Occupation Volume Research Articles

A novel three axis Semi Elliptic Manipulator Configuration for simultaneous Multi Point Operations

A new three axes robotic configuration named as “Semi Elliptic Configuration” has been explored here. The configuration’s topology, working principle, forward kinematics, inverse kinematics and application have been described in this article. The inverse and forward kinematic equations have been derived using more fundamental mathematical tools like plane coordinate geometry, trigonometry and properties of triangles instead of using DH parameters, Transformation and Jacobian matrices. The configuration’s name has been derived from the unconventional geometry of the work volume within which it operates. Unlike the cubically shaped work volume of a typical XYZ Cartesian robotic configuration, its shape has been warped towards the edge containing the vertical Z-axis. It was found that the edges enclosing the face opposite to the Z-axis is part of an Ellipse. Two mutually perpendicular co-planar arms originating from the Z-axis enclose the semi elliptic boundary. Two manipulators of such configuration could be accommodated and be made to work independently within the cubical volume occupied by the perpendicular arms. It was found that the configuration’s work volume leaves a void region within the volume of occupancy of the configuration’s structure, which proved to be a disadvantage in certain applications and an advantage in others. An enhancement has been proposed to work around this restriction. The modification allows the configuration to expand its work volume into the void regions. The superior version of the Semi elliptic configuration was named “Enhanced Semi Elliptic Configuration”.

Dynamics of Chiral Cations in Two-Dimensional CuX4 and PbX4 Perovskites (X = Cl and Br).

Chiral organic ammonium cations ((R)-2-methylphenethylammonium (R-MPhA) and (R)-3,7-dimethyloctylammonium (R-DMOA)) cations were combined with [MX4]2- anions (M = Cu and Pb, X = Cl and Br) to form two-dimensional (2D) perovskites: (R-MPhA)2CuCl4 (1a), (R-MPhA)2CuBr4 (1b), (R-DMOA)2CuCl4 (2a), (R-DMOA)2CuBr4 (2b), (R-DMOA)2PbCl4 (2c), and (R-DMOA)2PbBr4 (2d). The point shearing of the MX4 octahedron formed 2D perovskite layers, which were sandwiched by the bilayer molecular assembly of chiral organic ammonium cations. We found that the flexible and polar organic R-MPhA and R-DMOA cations in the 2D perovskites played an important role in the phase transition behavior and dielectric responses. Salts 2a-2d showed similar solid-solid (S1-S2) phase transitions, for which the temperatures decreased in the order of CuCl4 (2a) > PbCl4 (2c) > CuBr4 (2b) > PbBr4 (2d). The occupation volume of one R-DMOA per MX4 octahedron determined the dynamic crystalline space for the motional freedom of chiral ammonium in the 2D perovskite layer. Although thermally activated dielectric fluctuations were observed in salts 2a, 2b, and 2c, only an order-disorder-type dielectric phase transition was observed in salt 2d. Interband optical transitions were observed in the CuCl4 and CuBr4 2D perovskites, whereas sharp exciton absorptions were observed in the 2D PbCl4 and PbBr4 layers in perovskite salts 2c and 2d.

The Coronavirus Disease (COVID-19) Challenge in Mexico: A Critical and Forced Reflection as Individuals and Society.

OPINION article Front. Public Health, 26 June 2020Sec. Occupational Health and Safety Volume 8 - 2020 | https://doi.org/10.3389/fpubh.2020.00337

Volumetric study of the maxillary sinus in patients with sinus pathology.

The aim of this study is 1) to obtain the area and volumes of the maxillary sinuses in patients affected by clinically unilateral sinus pathology by comparing the results to the contralateral sinus and 2) to determine the importance of the volumetric measures when diagnosing the percentage of sinus obliteration. A single-centre observational retrospective clinical study was conducted in 214 patients with clinically unilateral sinus pathologies. Linear (mm), area (mm2) and volume (mm3) measurements were taken from Cone Beam Computed Tomography (CBCT) images of the affected sinus as well as from the contralateral ones. Histopathological study was performed using haematoxylin/eosin and PAS or Groccot stains. The lesions were classified into non-specific sinusitis, polyps, inverted papilloma, fungal sinusitis, cysts, mucocele and other lesions. Chi-squared test, ANOVA for independent samples and Pearson test were used for the statistical analysis. A total of 100 sinuses were measured in 50 patients (28 men and 22 women, with an age of 43.6 years (SD = 18.3), 50 pathological and 50 healthy contralateral sinuses. The three-dimensional occupation volume of the affected sinuses was 97.1 mm3 (62.5%) vs. 40.6 mm3 (22.8%) in the healthy ones (p<0.0001). The medial-lateral width of the sinus in the frontal plane was significantly higher in the cysts group (32.4 mm, CI: 23-41.8 mm). In medical terms, the global percentage of occupation determined using the classic manual determination method does not differ from the three-dimensional percentage calculated using specific complex software.

Attenuation Correction Approaches for Serotonin Transporter Quantification With PET/MRI.

BackgroundSeveral MR-based attenuation correction (AC) approaches were developed to conquer the challenging AC in hybrid PET/MR imaging. These AC methods are commonly evaluated on standardized uptake values or tissue concentration. However, in neurotransmitter system studies absolute quantification is more favorable due to its accuracy. Therefore, our aim was to investigate the accuracy of segmentation- and atlas-based MR AC approaches on serotonin transporter (SERT) distribution volumes and occupancy after a drug challenge.Methods18 healthy subjects (7 male) underwent two [11C]DASB PET/MRI measurements in a double-blinded, placebo controlled, cross-over design. After 70 min the selective serotonin reuptake inhibitor (SSRI) citalopram or a placebo was infused. The parameters total and specific volume of distribution (VT, VS = BPP) and occupancy were quantified. All subjects underwent a low-dose CT scan as reference AC method. Besides the standard AC approaches DIXON and UTE, a T1-weighted structural image was recorded to estimate a pseudo-CT based on an MR/CT database (pseudoCT). Another evaluated AC approach superimposed a bone model on AC DIXON. Lastly, an approach optimizing the segmentation of UTE images was analyzed (RESOLUTE). PET emission data were reconstructed with all 6 AC methods. The accuracy of the AC approaches was evaluated on a region of interest-basis for the parameters VT, BPP, and occupancy with respect to the results of AC CT.ResultsVariations for VT and BPP were found with all AC methods with bias ranging from −15 to 17%. The smallest relative errors for all regions were found with AC pseudoCT (<|5%|). Although the bias between BPP SSRI and BPP placebo varied markedly with AC DIXON (<|12%|) and AC UTE (<|9%|), a high correlation to AC CT was obtained (r2∼1). The relative difference of the occupancy for all tested AC methods was small for SERT high binding regions (<|4%|).ConclusionThe high correlation might offer a rescaling from the biased parameters VT and BPP to the true values. Overall, the pseudoCT approach yielded smallest errors and the best agreement with AC CT. For SERT occupancy, all AC methods showed little bias in high binding regions, indicating that errors may cancel out in longitudinal assessments.

A simulator study of driving behavior and mental workload in mixed-use arterial road environments

Objectives: Mixed-use urban environments, such as arterial roads with adjacent commercial land uses, represent crash locations with the highest risk. These locations are often characterized by high volumes of motor vehicle traffic, on-street parking, and interactions with multiple road user groups such as pedestrians, cyclists, and public transportation. The objective of this study was to investigate previously identified crash risk factors for mixed-use urban environments and assess how parking occupancy, center medians, and cyclist volume influence performance and workload in a driving simulator study.Methods: Thirty participants were recruited for the study. Participants completed 6 drives that presented different combinations of cyclist volume, median condition, and parking occupancy. Incorporated into the simulator drives was a secondary peripheral detection task (PDT) designed to measure mental workload. Participants provided subjective assessments of workload using the Rating Scale Mental Effort (RSME).Results: Mean lateral lane position was found to significantly vary across the 3 independent variables of parking occupancy, cyclist volume, and median conditions. No significant changes were identified for mean speed across the conditions. Subjective and objective measures of workload identified changes due to the presence of cyclists with slower reaction times for the PDT task when cyclists were present.Conclusion: The findings provide insight into the interaction of road design elements in mixed-use urban road environments and demonstrate that increasingly complex environments increase driver demand. This has important road design implications for mixed-use arterial roads, which are often characterized by complex interactions between multiple road user groups.

Life cycle assessment of a rainwater harvesting system compared with an AC condensate harvesting system

This study presents a life cycle assessment (LCA) of a rainwater harvesting (RWH) system and an air-conditioning condensate harvesting (ACH) system for non-potable water reuse. U.S. commercial buildings were reviewed to design rooftop RWH and ACH systems for one- to multi-story buildings’ non-potable water demand. A life cycle inventory was compiled from the U.S. EPA’s database. Nine scenarios were analyzed, including baseline RWH system, ACH system, and combinations of the two systems adapted to 4-story and 19-story commercial buildings in San Francisco and a 4-story building in Washington, DC. Normalization of 11 life cycle impact assessment categories showed that RWH systems in 4-story buildings at both locations outperformed ACH systems (45–80% of ACH impacts) except equivalent in Evaporative Water Consumption. However, San Francisco’s ACH system in 19-story building outperformed the RWH system (51–83% of RWH impacts) due to the larger volume of ACH collection, except equivalent in Evaporative Water Consumption. For all three buildings, the combined system preformed equivalently to the better-performing option (≤4–8% impact difference compared to the maximum system). Sensitivity analysis of the volume of water supply and building occupancy showed impact-specific results. Local climatic conditions, rainfall, humidity, water collections and demands are important when designing building-scale RWH and ACH systems. LCA models are transferrable to other locations with variable climatic conditions for decision-making when developing and implementing on-site non-potable water systems.

The Food Waste Atlas: An important tool to track food loss and waste and support the creation of a sustainable global food system

This study presents a life cycle assessment (LCA) of a rainwater harvesting (RWH) system and an air-conditioning condensate harvesting (ACH) system for non-potable water reuse. U.S. commercial buildings were reviewed to design rooftop RWH and ACH systems for one- to multi-story buildings’ non-potable water demand. A life cycle inventory was compiled from the U.S. EPA’s database. Nine scenarios were analyzed, including baseline RWH system, ACH system, and combinations of the two systems adapted to 4-story and 19-story commercial buildings in San Francisco and a 4-story building in Washington, DC. Normalization of 11 life cycle impact assessment categories showed that RWH systems in 4-story buildings at both locations outperformed ACH systems (45–80% of ACH impacts) except equivalent in Evaporative Water Consumption. However, San Francisco’s ACH system in 19-story building outperformed the RWH system (51–83% of RWH impacts) due to the larger volume of ACH collection, except equivalent in Evaporative Water Consumption. For all three buildings, the combined system preformed equivalently to the better-performing option (≤4–8% impact difference compared to the maximum system). Sensitivity analysis of the volume of water supply and building occupancy showed impact-specific results. Local climatic conditions, rainfall, humidity, water collections and demands are important when designing building-scale RWH and ACH systems. LCA models are transferrable to other locations with variable climatic conditions for decision-making when developing and implementing on-site non-potable water systems.

Design and Implementtationg of an IPsec VPN Gateway Base on OpenWRT

IPSec VPN is a virtual private network technology implemented using the IPSec protocol. Aiming at the problem that the national secret algorithm is relatively less applied to network security products, a gateway based on Openwrt system equipment is designed. The OpenWRT system includes the complete strongswan software, making it easy to set up a VPN. The design replaces the aes algorithm, the sha256 algorithm and the ECDSA algorithm used in the IPSec VPN in the StrongSwan source code with the SM4, SM3 and SM2 algorithms respectively, and replaces the ECDSA-SHA256 certificate with the SM2-SM3 certificate according to the X509 certificate standard to achieve the national secret standard. The SM4, SM3 and SM2 algorithms are provided by the SSX0912 encryption chip, and the certificate is placed in the SSX0912 encryption chip for dense storage. It is proved that the scheme is completely feasible, and the IPSec VPN that can be realized can run stably for a long time and has high practical value. By setting up the development environment test, the gateway runs stably, has small delay, and has higher security, and the device has high communication speed, small occupation volume, high flexibility, and strong specificity.

Thermal Properties of Acylated Low Molecular Weight Chitosans

Acylated low molecular weight chitosans (LChA) were prepared from nucleophilic acylation of chitosan using acid anhydrides of short and medium chain length (4 - 10) to study the response of applied heat as a function of acyl chain length. Thermogravimetric analysis (TGA) revealed the decomposition of LChA consisted of glucosamine and acyl-glucosamine units around 141 - 151and#176;C to 400 - 410and#176;C. Both TGA and differential scanning calorimetry (DSC) analyses indicated that the introduction of acyl groups disrupted the hydrogen bonding of chitosan, the effect was more prominent as the degree of substitution and chain length of LChA increased. Grafting of acyl chains lowered the kinematic viscosity of LChA as the disruption of hydrogen bonding led to decreased hydrodynamic volume. Field emission scanning electron micrographs showed that LChA with longer chains having larger particle size due to bigger occupancy volume of acyl chains during spray drying.

Novel Trifluoromethylated Enobosarm Analogues with Potent Antiandrogenic Activity In Vitro and Tissue Selectivity In Vivo

Prostate cancer often develops antiandrogen resistance, possibly via androgen receptor (AR) mutations, which change antagonists to agonists. Novel therapies with increased anticancer activity, while overcoming current drug resistance are urgently needed. Enobosarm has anabolic effects on muscle and bone while having no effect on the prostate. Here, we describe the activity of novel chemically modified enobosarm analogues. The rational addition of bis-trifluoromethyl groups into ring B of enobosarm, profoundly modified their activity, pharmacokinetic and tissue distribution profiles. These chemical structural modifications resulted in an improved AR binding affinity-by increasing the molecular occupational volume near helix 12 of AR. In vitro, the analogues SK33 and SK51 showed very potent antiandrogenic activity, monitored using LNCaP/AR-Luciferase cells where growth, PSA and luciferase activity were used as AR activity measurements. These compounds were 10-fold more potent than bicalutamide and 100-fold more potent than enobosarm within the LNCaP model. These compounds were also active in LNCaP/BicR cells with acquired bicalutamide resistance. In vivo, using the AR-Luc reporter mice, these drugs showed potent AR inhibitory activity in the prostate and other AR-expressing tissues, e.g., testes, seminal vesicles, and brain. These compounds do not inhibit AR activity in the skeletal muscle, and spleen, thus indicating a selective tissue inhibitory profile. These compounds were also active in vivo in the Pb-Pten deletion model. SK33 and SK51 have significantly different and enhanced activity profiles compared with enobosarm and are ideal candidates for further development for prostate cancer therapy with potentially fewer side effects. Mol Cancer Ther; 17(9); 1846-58. ©2018 AACR.

Corrigendum.

Classen, S. (2018). Editorial: Growth and Advances of OTJR. OTJR: Occupation, Participation and Health, 38, 3-5. DOI: 10.1177/1539449217747419 On page 3 of OTJR: Occupation, Participation and Health Volume 38(1), the core editorial team was incorrectly identified. The corrected sentence is provided below: Specifically-we have doubled the size of the core editorial team (which consists of editor-in-chief, assistant editor, and editorial fellow), more than doubled the size of the editorial board members (which consists of associate editors and review board members), and created and filled 13 new positions on the editorial board.

Hospital Strategies for Reducing Emergency Department Crowding: A Mixed-Methods Study

Emergency department (ED) crowding and patient boarding are associated with increased mortality and decreased patient satisfaction. This study uses a positive deviance methodology to identify strategies among high-performing, low-performing, and high-performance improving hospitals to reduce ED crowding. In this mixed-methods comparative case study, we purposively selected and recruited hospitals that were within the top and bottom 5% of Centers for Medicare & Medicaid Services case-mix-adjusted ED length of stay and boarding times for admitted patients for 2012. We also recruited hospitals that showed the highest performance improvement in metrics between 2012 and 2013. Interviews were conducted with 60 key leaders (physicians, nurses, quality improvement specialists, and administrators). We engaged 4 high-performing, 4 low-performing, and 4 high-performing improving hospitals, matched on hospital characteristics including geographic designation (urban versus rural), region, hospital occupancy, and ED volume. Across all hospitals, ED crowding was recognized as a hospitalwide issue. The strategies for addressing ED crowding varied widely. No specific interventions were associated with performance in length-of-stay metrics. The presence of 4 organizational domains was associated with hospital performance: executive leadership involvement, hospitalwide coordinated strategies, data-driven management, and performance accountability. There are organizational characteristics associated with ED decreased length of stay. Specific interventions targeted to reduce ED crowding were more likely to be successfully executed at hospitals with these characteristics. These organizational domains represent identifiable and actionable changes that other hospitals may incorporate to build awareness of ED crowding.

Analysis of CO2 monitoring data demonstrates poor ventilation rates in Albanian schools during the cold season

Poor ventilation in schools is associated with accumulation of indoor-generated pollutants, which is associated with “stuffy” air, elevated risk of infectious diseases and impaired learning outcomes. This survey in Albania was conducted as part of WHO’s efforts to facilitate assessments of indoor air quality and other environmental factors in schools in the European Region. The survey was conducted in 36 classrooms in 12 middle schools (eight urban and four rural) from December 2011 through March 2012. In each school, carbon dioxide (CO2) was continuously measured in three classrooms during one school week. Ventilation rates during classes were estimated using the build-up and steady-state mass balance equations utilizing CO2 concentration data, classroom occupancy and classroom volume. All 12 schools had gravimetric ventilation systems. Heating systems were absent or not operational in most schools. Average classroom temperatures during lessons varied from 9.1 to 14.4 °C (median 11.7 °C) with lower temperature associated with poorer ventilation. Weekly average CO2 levels during classes ranged from 1286 to 5546 ppm (median 2776 ppm) while average ventilation rates ranged from 0.8 to 3.6 (median 1.8) litres per second per person. Classrooms with indoor combustion heaters had higher indoor temperature, lower CO2 levels and higher levels of carbon monoxide (CO). WHO guidelines on 1- and 8-h CO exposure levels were exceeded in one classroom. Classroom CO2 levels were substantially above and ventilation rates below existing national and international guidelines. Detrimental impacts of poor ventilation on health and learning outcomes are likely to be substantial in Albanian schools during the cold season. Indoor temperature in most classrooms was below the commonly recommended levels.

Main Effects Ensured by Symmetric Circular Slots Etched on the Radiating Patch of a Compact Monopole Antenna on the Impedance Bandwidth and Radiation Patterns

Three compact monopole ultrawideband (UWB) antennas with half-wavelength symmetric circular slots etched on the radiating patch and operating in the UWB spectrum are proposed. Parametric studies followed by experimental results of the return loss coefficient S11 versus the circular slot length prove dual ensured functions. In fact, a switching from an impedance mismatch to an impedance matching appears when we replace a semicircular etched slot by a small circular slot while maintaining its inner radius constant. Simulated and measured reflection coefficient S11 of a fabricated prototype with a stack of two small circular slots concord well and prove an impedance bandwidth enhancement that covers 3.9–14 GHz frequencies band (S11 < −10 dB) compared to the impedance bandwidth 3.55–4.77 and 7.65–11.08 GHz (S11 < −10 dB) of the baseline antenna without slots. In addition, measured radiation patterns in the H-plane of the monopole with two etched symmetric slots, are stably omnidirectional at 5.8 and 7.5 GHz. It is noted that due to some strong transverse currents around the small circular symmetric embedded slots, the cross-polarization in the same plane and at the same frequencies are not as low as single monopole. We noticed that there appears to be a close correspondence between the minimum of EФ and the maximum of Eθ electrical components. That is to say, the signals of the co-polarizations are irrelevant to those of the cross-polarizations. Due to its impedance matching and its stable omnidirectional radiation patterns, reliability and the reduced occupation volume, the proposed printed monopole with two etched small symmetric circular slots is suitable for the emerging applications of the wireless technology.

Evaluation of the operating conditions for the solid-state production of pectinases by Aspergillus niger in a bench-scale, intermittently agitated rotating drum bioreactor

Pectinase production by Aspergillus niger LB-02-SF was studied in a bench-scale rotating drum bioreactor. With 30% of the bioreactor volume occupied, agitation promoted increasing fungal growth and decreasing enzyme production, whereas with 50% occupation, an opposite trend occurred. The interval between agitation events was evaluated for an occupation volume of 70%, and no difference in enzyme production was observed for the 90 and 120 min intervals; for the 60 min intervals, however, the activity was reduced. Cultivations performed without temperature control attained 45 °C and showed maximum enzyme activity almost four times superior to cultivations controlled at 30–37 °C. Air flow rates between 0.18 and 0.90 L of air per kilogram of medium per minute were evaluated for 30 and 50% of the occupation volume. Fungal growth and pectinase production were favoured by the smallest and largest occupation volumes, respectively, with an intermediate air flow. The results of this work indicate that the best conditions for biomass growth are not the best for the production of pectinases.

144 Hospital Strategies for Reducing Emergency Department Crowding: A Mixed-Methods Study

Emergency department (ED) crowding and patient boarding are associated with increased mortality and decreased patient satisfaction. Despite years of quality and safety research, effective strategies to reduce ED crowding are not well elucidated. We identify potential hospital “best practices” to decrease ED crowding. Mixed methods comparative case study. We purposively selected and recruited hospitals that were within the top and bottom 5% of Centers for Medicare and Medicaid Services case-mix-adjusted ED length-of-stay metrics for both 2012 and 2013, including length of stay and boarding times for admitted patients. We conducted semi-structured interviews with 4-6 people at each hospital involved with ED throughput and crowding process improvement, including hospital administration (eg, CEO, CMO, CNO), inpatient care (eg, internal medicine), and ED operations. We analyzed interviews using a grounded theory approach and identified best practices to improve ED crowding. We engaged 4 high performing and 4 low performing hospitals, matched on hospital characteristics including geographic designation (urban versus rural), region, hospital occupancy, and ED volume. We conducted 38 interviews across sites. Across all hospitals, ED crowding was recognized as a hospital-wide issue, yet the strategies for addressing ED crowding varied widely. Strategies that were common in high- and low-performing hospitals included: improvement of front end processes including physician in triage and nurse-initiated protocols; hiring consultants to utilize LEAN methods; and data-driven strategies shared amongst team members and other departments. Low-performing hospitals expressed barriers to care that included nursing shortages, lack of resources for change, and lack of support from hospital-level leadership. In contrast, high-performing hospitals reported that executive leadership was significantly engaged in efforts to reduce ED crowding. This engagement was characterized by use of data to model and predict patient flow to staff appropriately; reporting of metrics to hospital-wide leadership on a daily basis; and proactive strategies that are implemented at various levels of crowding. The leadership created multi-disciplinary teams composed ED staff, professionals from a variety of departments, and professional backgrounds in the quality improvement process. High-performing hospitals reported making multiple changes concurrently to reduce front end (ED), throughput, and back end (ie, inpatient discharge) processes. These efforts led to hospital-wide coordination to decrease radiology, lab, and bed turnover times. Interviewees were able to easily identify metrics to which they were held accountable; in addition, once metrics were met there was a continuous improvement process to evaluate, modify, and enhance current processes. High-performing hospitals commonly engaged in proactive, as opposed to reactive, strategies, including flexibility in utilization of their physical space in both the ED and inpatient settings. We identified several best practices, including concurrent changes in all steps of hospital-wide flow, strong executive leadership, continuous data feedback and improvement that were tied to high performance on ED crowding metrics. While further research might assess the causal link between these strategies and ED crowding, these practices represent actionable changes that other EDs may incorporate.

Large-scale molecular dynamics simulation of crosslinked phenolic resins using pseudo-reaction model

Abstract We constructed and characterized a network structure of crosslinked phenolic resins using a large-scale atomistic molecular dynamics simulation with a pseudo-reaction algorithm. The atomic configuration of the reaction products was controlled by the reaction probabilities and initial molecular structures. The crosslinked structure obtained from phenols as initial molecules agreed well with experimental results in terms of the branching structure of the phenolic units and the methylene linkages, molecular weight distributions, densities, and scattering functions at various reaction conversions. The calculated structure factor for phenolic resins indicated inhomogeneous crosslinking, which expanded as the reaction proceeded after gelation. Voronoi tessellation analysis of the change in the occupation volume of the phenolic units after crosslinking indicated that the initial molecular configuration influenced the resulting crosslinked structure. The experimental molecular weight distribution before gelation and the scattering function were well reproduced by a large-scale simulation with 232,000 atoms.

Imaging α4β2 Nicotinic Acetylcholine Receptors (nAChRs) in Baboons with [18F]XTRA, a Radioligand with Improved Specific Binding in Extra-Thalamic Regions.

Currently available positron-emitting radiotracers for imaging of the α4β2 subtype of nicotinic acetylcholine receptors (nAChRs) exhibit high and moderate specific binding in the thalamus and extra-thalamic brain regions, respectively. In many neuropsychiatric disorders, α4β2-nAChRs are altered in the extra-thalamic brain regions, but not necessarily in the thalamus. The purpose of this study was to evaluate [18F]XTRA, a new α4β2-nAChR positron emission tomography (PET) radioligand with improved specific binding in extra-thalamic brain regions, in non-human primates. The regional distribution of [18F]XTRA in the brain of Papio anubis baboons was evaluated in baseline and blocking experiments. Various PET modeling procedures were used for determination of volume of distribution (V T), binding potential (BPND), and receptor occupancy. Radiation dosimetry for [18F]XTRA was studied in male CD-1 mice and extrapolated to human dosimetry estimates using OLINDA/EXM software. [18F]XTRA was synthesized using an automated radiochemistry module with 25% decay-corrected radiochemical yield. [18F]XTRA readily enters the baboon brain and specifically labels α4β2-nAChRs. Mathematical modeling demonstrates high binding potential values (BPND=7 and 1.3 in the thalamus and frontal cortex, respectively). A PET scanning time of 90-120min was sufficient to obtain stable V T values in the extra-thalamic regions. The extrapolated human effective dose was 0.041mSv/MBq (0.15Rem/mCi). [18F]XTRA exhibits improved specific binding in the baboon brain including extra-thalamic regions and it is considered radiologically acceptable for human studies. Further evaluations of [18F]XTRA in human subjects are under way.

A probabilistic approach to workspace sharing for human–robot cooperation in assembly tasks

Abstract Recently, human–robot cooperation (HRC) research activities have focused on the development of new methodologies for the generation of safe robot trajectories. However, the applicability of such methodologies in a real context is limited due to the inherent uncertainty of robot trajectory execution time (i.e. the robot can avoid the worker by modifying its velocity along the path). This paper proposes an approach to estimate a confidence interval on robot trajectory execution time for scenarios in which human–robot space sharing is required. First, human arm movements are studied for a given set of assembly collaborative tasks: worker occupancy volumes and occupancy volume probabilities are derived. Then, a finite number of alternative robot trajectories, crossing human occupancy volumes with different occupancy probabilities, are generated. It is therefore possible to estimate a probability for the robot to reduce its velocity, and a confidence interval on the robot execution time. The application on a real assembly case is discussed.