Search

The purpose of this study was to evaluate the association between aortic endograft diameter and long-term outcomes following endovascular aneurysm repair (EVAR) performed in accordance with manufacturer instructions for use (IFU).A retrospective review of consecutive patients undergoing on-IFU EVAR (2000-2018) was performed to facilitate a comparative analysis of long-term patient outcomes based on device diameter. "Large diameter" devices were defined as34 mm. The primary outcome of interest was freedom from sac expansion throughout long-term follow-up. Analyses included standard bivariate analyses, Kaplan-Meier with log-rank comparison, and Cox proportional hazards multivariate analysis.A total of 1,099 underwent on-IFU EVAR from 2000-2018. Follow-up data were available for 980 patients. Of these, 75 patients (7.6%) were treated with34-mm devices. There were no significant differences in demographics or comorbidities between the 2 groups, although preoperative abdominal aortic aneurysm size was greater in patients undergoing implantation of34-mm devices (58 ± 8.5 mm vs. 56 ± 17.4 mm; P = 0.05). Median follow-up was 10.3 years. Patients with grafts34 mm had reduced freedom from sac expansion throughout follow-up (P = 0.038). There were no significant differences in reintervention rates, open conversion, or rupture when stratified by graft diameter. A multivariate Cox regression identified patient age, preoperative abdominal aortic aneurysm size, need for reintervention, and use of34-mm endografts as independent factors associated with expansion.The use of large diameter aortic endografts is associated with higher rates of sac expansion during long-term follow-up. Although there is undoubtedly a role for large diameter graft use in selected patients, it is important to recognize that these devices were typically approved post hoc without the same regulatory scrutiny of smaller endografts. These findings underscore the importance of ongoing surveillance for patients treated with34-mm grafts, irrespective of compliance with manufacturer IFU.

BackgroundElevated rates of alcohol, tobacco, and cannabis use are observed in both patients with psychotic disorders and individuals at clinical high risk for psychosis (CHR-P), and strong genetic associations exist between substance use disorders and schizophrenia. While individuals with 22q11.2 deletion syndrome (22qDel) are at increased genetic risk for psychosis, initial evidence suggests that they have strikingly low rates of substance use. In the current study, we aimed to directly compare substance use patterns and their neurobehavioral correlates in genetic and clinical high-risk cohorts.MethodsData on substance use frequency and severity, clinical symptoms, and neurobehavioral measures were collected at baseline and at 12-month follow-up visits in two prospective longitudinal cohorts: participants included 89 22qDel carriers and 65 age and sex-matched typically developing (TD) controls (40.67% male, Mage = 19.26 ± 7.84 years) and 1,288 CHR-P youth and 371 matched TD controls from the North American Prodrome Longitudinal Study-2 and 3 (55.74% male; Mage = 18.71 ± 4.27 years). Data were analyzed both cross-sectionally and longitudinally using linear mixed effects models.ResultsControlling for age, sex, and site, CHR-P individuals had significantly elevated rates of tobacco, alcohol, and cannabis use relative to TD controls, whereas 22qDel had significantly lower rates. Increased substance use in CHR-P individuals was associated with increased psychosis symptom severity, dysphoric mood, social functioning, and IQ, while higher social anhedonia was associated with lower substance use across all domains at baseline. These patterns persisted when we investigated these relationships longitudinally over one-year. CHR-P youth exhibited significantly increased positive psychosis symptoms, dysphoric mood, social functioning, social anhedonia, and IQ compared to 22qDel carriers, and lower rates of autism spectrum disorder (ASD) compared to 22qDel carriers, both at baseline and at 1 year follow-up.ConclusionIndividuals at genetic and CHR-P have strikingly different patterns of substance use. Factors such as increased neurodevelopmental symptoms (lower IQ, higher rates of ASD) and poorer social functioning in 22qDel may help explain this distinction from substance use patterns observed in CHR-P individuals.

BackgroundChoroid plexus (ChP) enlargement has been described in first-episode psychosis and psychosis spectrum disorders, but whether ChP enlargement occurs before disease onset is unknown. This study investigated whether ChP volume is enlarged in individuals with clinical high-risk (CHR) for psychosis and whether these changes are related to clinical, cortical, and plasma analyte measures.MethodsClinical and neuroimaging data from the North American Prodrome Longitudinal Study 2 (NAPLS2) was used for analysis. A total of 509 participants (169 controls, 340 CHR) were recruited across 8 sites. Conversion status was determined until 2-years of follow-up, with 36 patients developing psychosis. The lateral ventricle ChP was manually segmented from all available baseline brain scans. A subsample of 84 participants (31 controls, 53 CHR) had plasma analyte and neuroimaging data.ResultsCompared to controls, CHR overall (d=0.22, p=0.017) and converters(d=0.21, p=0.041)demonstrated higher ChP volumes, but not nonconverters. In CHR, greater ChP volume correlated with lower cortical(r=−0.22, pand subcortical gray matter volume(r=− 0.21, p, total white matter volume(r=−0.28,p, and larger lateral ventricle volume(r=0.63,p. In CHR, greater ChP volume, but not lateral ventricle volume, correlated with higher C3(r=0.39, p=0.005)and TSH(r=0.31, p=0.026), and lower MMP7(r=−0.30, p=0.032)and UMOD(r=−0.33, p=0.019).Conclusions and RelevanceCHR and converters to psychosis demonstrated significantly larger ChP volumes compared to controls. ChP enlargement was associated with cortical volume reduction and increased peripheral inflammatory markers. These findings suggest that the ChP may be a key biomarker in psychosis disease onset and conversion.

Aberrant subclavian arteries (aSCA), with or without aortic pathology are uncommon. The purpose of this study is to review our experience with surgical management of aSCA.We performed a retrospective review of patients who underwent surgery for aSCA between 1996-2020. Symptomatic and asymptomatic patients were included. Primary endpoints were ≤ 30 day and late mortality. Secondary endpoints were ≤ 30-day complications, graft patency, and re-interventions.Forty-six symptomatic and 3 asymptomatic patients with aSCA underwent surgical treatment (female: 31, 62%; median age 45 years). Aberrant right subclavian artery (aRSCA) was present in 38 (78%), and aberrant left subclavian artery (aLSCA) in 11 (22%). Forty-one (84%) had a Kommerell diverticulum (KD) and 11(22%) had concomitant distal arch or proximal descending thoracic aortic (DA/PDTA) aneurysm. Symptoms included dysphagia (56%), dyspnea (27%), odynophagia in (20%), and upper extremity exertional fatigue in (16%). Five patients (10%) required emergency surgery. The aSCA was treated by transposition in 32, carotid to subclavian bypass in 11 and ascending aorta to subclavian bypass in 6. KD was treated by resection and oversewing in 19 (39%). Fifteen (31%) required DA/PDTA replacement for concomitant aortic disease and/or KD treatment. TEVAR was used to exclude the KD in 6 (12%). Seven patients (14%) had only bypass or transposition. 30-day complications included one death from pulseless electrical activity arrest secondary to massive pulmonary embolism. 30-day major complications (14%) included acute respiratory failure in 3, early mortality in 1, stroke in 1, NSTEMI in 1, and 1 temporary dialysis in 1. Others included 5 (10%) chylothorax/lymphocele, 2 (4%) acute kidney injury (AKI), 2 (4%) pneumonia, 2 (4%) wound infection, 2 (4%) atrial fibrillation, 2 (4%) Horner syndrome, 1 (2%) lower extremity acute limb ischemia (ALI) and 1 (2%) left recurrent laryngeal nerve injury. At median follow up of 53 months (range 1-230), 40 (80%) patients had complete symptom relief and 10 (20%) had improvement. Six late deaths occurred at a median of 157 months and were not procedure or aortic related. Primary patency was 98%. ≤ 30-day re-interventions occurred in 2 (4%) for ligation of lymphatics and bilateral lower extremity fasciotomy after proximal DTA replacement. One patient required late explant of an infected and occluded carotid to subclavian bypass graft; treated by cryopreserved allograft replacement.Surgical treatment of the aSCA can be accomplished with low major morbidity and mortality with excellent primary patency and symptom relief.

Introduction Ocean Worlds, and their subsurface oceans, are prime targets in the search for exobiology. Access to these sub-ice oceans presents many engineering challenges. THOR (Thermal High-voltage Ocean-penetrator Research platform) is a prototype for a new class of Ocean World exploration vehicle which combines elements of an ice-penetrator (cryobot) and an ocean-profiler (sonde). This ice/ocean profiler (IOP) will carry a sampling subsystem and spatial, environmental, and life-detection sensors to characterize the ice and water column. Using the THOR platform and sensor suite, we are developing test strategies and behaviors for autonomous exploration and sampling as the vehicle descends through an ice column and into and through a subglacial lake. THOR is funded through the NASA PSTAR program (Grant 80NSSC18K1738). THOR builds upon three breakthroughs in cryobot technology achieved in the NASA-funded VALKYRIE and SPINDLE projects: Onboard closed-cycle hot-water drilling (CCHWD); small-diameter high-voltage, high-power tether technology; and high voltage fluid-resistor water heating. These concepts were tested as sub-scale assemblies in the lab or in limited field tests. THOR scales up and integrates these approaches into a high-efficiency cryobot that is sized to incorporate the Kilopower fission reactor as its thermal power source. With hot water jets in the nose and tail, THOR can melt its way both downwards through ice as well as upwards through the refrozen ice behind it. The vehicle concept is the first to incorporate a Vertical Motion Control System (VMCS) that includes onboard servo spoolers to pay out or retrieve power, communications, and strength tethers as the vehicle descends or ascends. Our goal with THOR is to conduct the first cryobot descent into a terrestrial subglacial lake. Here we present the Phase I vehicle final design, key features of the operational core CCHWD system, and the recent results of lab testing of a simulated 700 m continuous descent in temperate glacier ice conditions and penetration tests through ice containing tephra deposits. Vehicle Architecture THOR is a flight-scale cryobot based on closed-cycle hot water drill technology. CCHWD has been demonstrated to achieve a melting metric (kWH/m3 of melted ice) of approximately twice that of passive thermal probes and can penetrate glacial debris in polar regions on Earth. THOR is sized to carry the NASA 40 kWth Kilopower reactor as the thermal and electrical power source for future sub-ice missions to Europa and other Ocean World targets. THOR Phase I work focused on the design and performance of the CCHWD melt head. Currently, the Kilopower reactor is not available for terrestrial cryobot testing, so we needed to emulate the Kilopower geometry and thermal output with a nuclear surrogate. There are three key components to the THOR power transmission approach. To create a nuclear surrogate, surface power is currently provided by a diesel generator (50 kW single phase 240 AC; the system is designed to handle up to 100 kW). Power is then routed to an up-converter that raises the voltage to 10 kV AC. Finally, a small fraction of power is converted for use by the onboard pumps, computers, sensors, and valves. The full 10 kV is used directly in the thermal power conversion module, known as HOTSHOT. The estimated descent performance in temperate ice is approximately 10 m/hour at 50 kW input power. Figure 1. THOR Phase I and Phase II Vehicle Architecture In general the cryobot descent speed will be inversely proportional to the square of the vehicle diameter and directly proportional to the ice temperature (which varies with depth) and the input power. On the basis of a kWH/m3 performance metric, THOR will compete with traditional terrestrial hot water drills in terms of speed. Its logistics footprint, however, is substantially smaller. Furthermore, bi-directional cryobots like THOR enable persistent subglacial science. Larger diameter cryobots can be used to transport, release, and retrieve science payloads as well as autonomous vehicles to subglacial aqueous environments. HOTSHOT: Turning Lightning Bolts into Heat The CCHWD system forms the core of the THOR technologies developed for Phase I. The goal of the system is to enable THOR to achieve high penetration rates by using high-pressure water jets to rapidly transfer heat into the ice from a novel direct high voltage heater system called HOTSHOT. The HOTSHOT technology is a critical enabler for terrestrial cryobot missions which are not able to use nuclear power sources. The HOTSHOT heater developed for THOR passes high-voltage (10 kV), low current, AC power through a moving conducting fluid. This creates resistive heating in the fluid with 100% efficiency without inducing electrolysis. Power densities as high as 600 kW/liter have been achieved with the HOTSHOT design. The overall system consists of two loops: a completely internal fully-closed process loop to allow for tight control of the fluid resistivity in HOTSHOT, and the environmental loop which heats the surrounding ice via jetting. The HOTSHOT concept has been extensively tested at Stone Aerospace and was used during the full power 72 hour burn test. Figure 2. HOTSHOT, a novel direct high voltage heater system Long Duration Testing: Simulating an Antarctic Mission Due to the Covid-19 pandemic we were not able to perform field tests of THOR at the Matanuska Glacier (Alaska, USA) as we originally planned. Instead we tested the integrated THOR CCHWD melt head at full power in a simulated long duration mission. This Long Duration Test (LDT) simulated a 700 m ice penetrating mission by operating THOR in an insulated subzero (-0.5 C) water bath with a field-realistic power supply and high voltage (9.2 kV avg) delivery system. The vehicle achieved a peak thermal power of 45 kW and the HOTSHOT nuclear surrogate and sustained an average power of 37 kW over 72 hours of operation. The Closed Cycle Hot Water Drill (CCHWD) design delivered a 30 L/min flow from the nose jet at an average temperature 14C above the surrounding water. Optimizing the thermal distribution along the length of the cryobot is planned for Phase 2. Figure 3. Underwater still image capture in the test tank during THOR jet firing

Background In some settings, sensitive field diagnostic tools may be needed to achieve elimination of falciparum malaria. To this end, rapid diagnostic tests (RDTs) based on the detection of the Plasmodium falciparum protein HRP-2 are being developed with increasingly lower limits of detection. However, it is currently unclear how parasite stages that are unaffected by standard drug treatments may contribute to HRP-2 detectability and potentially confound RDT results even after clearance of blood stage infection. In this study, we assessed the detectability of HRP-2 in periods of post-treatment residual gametocytaemia. Methods A cohort of 100 Plasmodium falciparum infected, gametocyte positive individuals were treated with or without the gametocytocidal drug primaquine (PQ), alongside standard artemisinin-based combination therapy (ACT), in the context of a randomised clinical trial in Ouelessebougou, Mali. We used a quantitative ELISA to measure levels of HRP-2, and compared time to test negativity using a standard and ultra-sensitive RDT (uRDT) between residual gametocyte positive and negative groups. Findings Time to test negativity was longest by uRDT, followed by ELISA and then standard RDT. No significant difference in time to negativity was found between the treatment groups with and without residual gametocytes: uRDT (HR 0.79 [95% CI 0.52–1.21], p = 0.28), RDT (HR 0.77 [95% CI 0.51–1.15], p = 0.20) or ELISA (HR 0.88 [95% CI 0.59–1.32], p = 0.53). Similarly, no difference was observed when adjusting for baseline asexual parasite density. Quantified levels of HRP-2 over time were similar between groups, with differences attributable to asexual parasite densities. Furthermore, no difference in levels of HRP-2 was found between individuals who were or were not infectious to mosquitoes (OR 1.19 [95% CI 0.98–1.46], p = 0.077). Interpretation Surviving sexual stage parasites after standard ACT treatment do not contribute to the persistence of HRP-2 antigenaemia, and appear to have little impact on RDT results.

Summary Background Pyronaridine–artesunate is the most recently licensed artemisinin-based combination therapy. WHO has recommended that a single low dose of primaquine could be added to artemisinin-based combination therapies to reduce Plasmodium falciparum transmission in areas aiming for elimination of malaria or areas facing artemisinin resistance. We aimed to determine the efficacy of pyronaridine–artesunate and dihydroartemisinin–piperaquine with and without single low-dose primaquine for reducing gametocyte density and transmission to mosquitoes. Methods We conducted a four-arm, single-blind, phase 2/3, randomised trial at the Ouélessébougou Clinical Research Unit of the Malaria Research and Training Centre of the University of Bamako (Bamako, Mali). Participants were aged 5–50 years, with asymptomatic P falciparum malaria mono-infection and gametocyte carriage on microscopy, haemoglobin density of 9·5 g/dL or higher, bodyweight less than 80 kg, and no use of antimalarial drugs over the past week. Participants were randomly assigned (1:1:1:1) to one of four treatment groups: pyronaridine–artesunate, pyronaridine–artesunate plus primaquine, dihydroartemisinin–piperaquine, or dihydroartemisinin–piperaquine plus primaquine. Treatment allocation was concealed to all study staff other than the trial pharmacist and treating physician. Dihydroartemisinin–piperaquine and pyronaridine–artesunate were administered as per manufacturer guidelines over 3 days; primaquine was administered as a single dose in oral solution according to bodyweight (0·25 mg/kg; in 1 kg bands). The primary endpoint was percentage reduction in mosquito infection rate (percentage of mosquitoes surviving to dissection that were infected with P falciparum) at 48 h after treatment compared with baseline (before treatment) in all treatment groups. Data were analysed per protocol. This trial is now complete, and is registered with ClinicalTrials.gov, NCT04049916. Findings Between Sept 10 and Nov 19, 2019, 1044 patients were assessed for eligibility and 100 were enrolled and randomly assigned to one of the four treatment groups (n=25 per group). Before treatment, 66 (66%) of 100 participants were infectious to mosquitoes, with a median of 15·8% (IQR 5·4–31·9) of mosquitoes becoming infected. In individuals who were infectious before treatment, the median percentage reduction in mosquito infection rate 48 h after treatment was 100·0% (IQR 100·0 to 100·0) for individuals treated with pyronaridine–artesunate plus primaquine (n=18; p

Spinocerebellar ataxia type 7 (SCA7) is a neurodegenerative disease caused by a trinucleotide CAG repeat. SCA7 predominantly causes a loss of photoreceptors in the retina and Purkinje cells of the cerebellum. Severe infantile-onset SCA7 also causes renal and cardiac irregularities. Previous reports have shown that SCA7 results in increased susceptibility to DNA damage. Since DNA damage can lead to accumulation of senescent cells, we hypothesized that SCA7 causes an accumulation of senescent cells over the course of disease. A 140-CAG repeat SCA7 mouse model was evaluated for signs of disease-specific involvement in the kidney, heart, and cerebellum, tissues that are commonly affected in the infantile form. We found evidence of significant renal abnormality that coincided with an accumulation of senescent cells in the kidneys of SCA7140Q/5Q mice, based on histology findings in addition to RT-qPCR for the cell cycle inhibitors p16Ink4a and p21Cip1 and senescence-associated ß-galactosidase (SA-ßgal) staining, respectively. The Purkinje layer in the cerebellum of SCA7140Q/5Q mice also displayed SA-ßgal+ cells. These novel findings offer evidence that senescent cells accumulate in affected tissues and may possibly contribute to SCA7’s specific phenotype.

Bullying is associated with a heightened risk for poor outcomes, including psychosis. This study aimed to replicate previous findings on bullying prevalence in clinical high-risk (CHR) individuals, to assess the longitudinal course of clinical and functional variables between bullied and non-bullied CHR and the association of bullying with premorbid functioning, clinical outcome, transition to psychosis and risk of violence.The sample consisted of 691 CHR participants and 96 healthy controls. Participants reported whether they had experienced bullying and how long it had lasted. Assessments included DSM-5 diagnoses, attenuated psychotic symptoms, negative symptoms, social and role functioning, depression, stress, premorbid functioning, and risk of violence. The bullied and non-bullied CHR groups were compared at baseline and further longitudinally on clinical and functioning variables and transition to psychosis.Bullying was more prevalent among CHR individuals than healthy controls. Bullied CHR had a higher prevalence of PTSD and more severe depression and stress at baseline than non-bullied CHR. There was no impact of bullying on clinical and functional variables over time. Bullying was not related to final clinical status or transition to psychosis. However, bullied participants had poorer premorbid functioning and a greater risk of violence.While bullying may not impact the likelihood of CHR individuals to transition to psychosis, it may be a risk factor for development of the at-risk state and may be related to a greater risk of violence. Future studies should consider bullying perpetration among CHR individuals.

Vehicle to everything (V2X) in heterogeneous networks concurrently retains multiple communication links within a channel: such as vehicle to vehicle (V2V), Vehicle to macro base station (V2C), and cellular user equipment to femtocell base station (U2F). To provide high spectral efficiency, there were many efforts such as non-orthogonal multiple access (NOMA) and channel aggregation. However, combining these schemes on the top of NOMA-V2X-femtocell is extremely challenging as it increases the number of dimensions to be considered. To address this issue, this paper proposes a new genetic deep learning algorithm. It employs a genetic algorithm (GA) to find a pair of communication links per channel in a way to maximize the throughput and a neural network to reduce the dimension gradually. The neural network is trained to predicts which pair can be part of the final result. The suitable pairs are marked by deep learning, then they are not shuffled in the subsequent generations. The simulation results show that the proposed scheme achieved higher throughput greater than 20%, compared to the existing GA.

Background Counseling patients with written materials relies equally on patients' health literacy to understand their disease and its treatment, and the written materials' effectiveness communicating clearly in accessible and actionable ways. Only about 12% of the US population is adequately health literate. Objectives To explore the impact of reducing the health literacy demands of written patient health information. Methods 805 patients were screened for health literacy, and recruited for balanced cohorts of adequate and low literacy, and high and normal blood pressure. Half of each patient cohort received either standard or “health literacy-friendly” drug summaries (i.e. Patient Package Inserts, or PPIs or “leaflets”) along with a standardized health literacy assessment scale. Results The literacy-friendly drug summary improved comprehension of drug-related information overall from 50% to 71% correct responses. Adequate literacy patients improved from 58% correct to 90%, while lower literacy patients improved from 42% to 52% correct in response to the health literacy-friendly PPIs. Conclusions Health literacy demands require special attention in developing and using written drug summary materials. Additionally, pharmacists should be provided additional information and counseling support materials to facilitate communications with low health literacy level patients.

In this paper, wind turbines dynamics are considered for nonlinear behavioral modeling and simulation. The modeling part is concerned about the wind turbines exposed to lower range of wind speeds. The nonlinear model considered in this paper is derived from the models published recently. The model then is analyzed through stability, eigenvalues, sensitivity and Simulink verification versus General Electric and NREL models. The paper then introduces analysis and simulations for the wind turbines dynamics approximated to fast–slow (two) time scales and fast–medium–slow (three) time scales. The multiple time scale simulation analysis and results we present are a continuation for our previous work (Eisa et al. in Int J Dyn Control 2017. https://doi.org/10.1007/s40435-017-0356-0 ) that concluded rigorous mathematical analysis for wind turbines dynamics. The paper presents full numerical simulation results for the time scale work. Finally, the paper presents a practical illustration by comparing the modeling work versus other models and real measured data from a wind farm.

When multiple blasts occur at different times, the situation arises in which a blast wave is propagating into a medium that has already been shocked. Determining the evolution in the shape of the second shock is not trivial, as it is propagating into air that is not only non-uniform, but also non-stationary. To accomplish this task, we employ the method of Kompaneets to determine the shape of a shock in a non-uniform media. We also draw from the work of Korycansky (Astrophys J 398:184–189. https://doi.org/10.1086/171847 , 1992) on an off-center explosion in a medium with radially varying density. Extending this to treat non-stationary flow, and making use of approximations to the Sedov solution for the point blast problem, we are able to determine an analytic expression for the evolving shape of the second shock. In particular, we consider the case of a shock in air at standard ambient temperature and pressure, with the second shock occurring shortly after the original blast wave reaches it, as in a sympathetic detonation.

In this study, a mathematical analysis of a wind turbine dynamics is presented. The model represented by control blocks and transfer functions taken from recognized papers and studies, is translated to a system of nonlinear differential algebraic equations. For easier computational and numerical study, we prove the existence of a unique terminal voltage solution, which eliminates the algebraic constraint. Our study provides rigorous proofs of boundedness, existence, and uniqueness for the initial value problem of the system, allowing for the assurance that convergent numerical solutions converge to a unique solution for a given initial condition. This allows scholars to have a free simulator that will aid in dynamical studies of wind turbines without the need for software and Simulink limitations. A safe region within grid parameter space (R and X) is defined, in which existence and uniqueness are guaranteed. We presented time scale analysis and simulations to show that the system can be studied in smaller sizes. Lastly, we introduce cases of two and three time scales.

Market researchers are used to asking questions. It is their job to query and probe “to gather information about markets or customers” (McQuarrie, 2016), but how adept are they at turning those questions inward? Have health care-related market researchers synthesized what is currently known about health literacy to inform their study designs or their participant recruitment goals?

In this paper, a model of type-3 Doubly Fed Asynchronous/Induction Generator (DFAG/DFIG) wind turbine is considered. We construct a system of 10 nonlinear differential equations that describes the transitional stage of dynamics when the rated speed is achieved and the rated power is not. A computation of the steady state vs. wind speed, stability in grid parameter space (resistance and reactance), and sensitivity of state variables and eigenvalues to parameters are presented in the paper. The paper recorded some sensitivity of eigenvalues to the reactance X. The paper presents simulations for a transitioning wind speed profile and a class of solutions with different wind speeds that start close to the equilibrium. These simulations are supporting the paper's conclusion.

Visual search techniques and FROC analysis have been widely used in radiology to understand medical image perceptual behaviour and diagnostic performance. The potential of exploiting the advantages of both methodologies is of great interest to medical researchers. In this study, eye tracking data of eight dental practitioners was investigated. The visual search measures and their analyses are considered here. Each participant interpreted 20 dental radiographs which were chosen by an expert dental radiologist. Various eye movement measurements were obtained based on image area of interest (AOI) information. FROC analysis was then carried out by using these eye movement measurements as a direct input source. The performance of FROC methods using different input parameters was tested. The results showed that there were significant differences in FROC measures, based on eye movement data, between groups with different experience levels. Namely, the area under the curve (AUC) score evidenced higher values for experienced group for the measurements of fixation and dwell time. Also, positive correlations were found for AUC scores between the eye movement data conducted FROC and rating based FROC. FROC analysis using eye movement measurements as input variables can act as a potential performance indicator to deliver assessment in medical imaging interpretation and assess training procedures. Visual search data analyses lead to new ways of combining eye movement data and FROC methods to provide an alternative dimension to assess performance and visual search behaviour in the area of medical imaging perceptual tasks.

In this paper, a type-3 Doubly Fed Asynchronous/ Induction Generator (DFAG/DFIG) wind turbine is considered for a dynamical study. The main blocks of the model taken from the literature are described and translated into a system of differential equations. By proving the possibility of eliminating the algebraic constraint, we are provided with good numerical possibilities to study wind turbine's dynamics. The paper provides a time domain analysis to emphasize and analyze the effect of adding a Q Drop function to the reactive power control dynamics. Our results, supported by simulations, suggest the important impact of the Q Drop function on the integrators blocks. The paper also provides an investigation of the system's attraction limits versus the control limits proposed by General Electric and others. The results, supported by simulations, questions the current models' validity, at least the proposed control limits.

In this paper, a type-3 Doubly Fed Asynchronous/InductionGenerator (DFAG/DFIG) wind turbine is considered for higher wind speeds with the pitch control activated. The purpose of the paper is to study the stability of wind turbine's when connected to the grid. The main blocks of the model that have been taken from the literature are described and translated into a system of differential equations with algebraic constraint. Time domain analysis for the system is provided by computing the steady states as functions of the wind speed and the grid parameters, testing eigenvalues sensitivity to the wind speed, and analyzing stability, including bifurcation in parameter space. The existence of a Hopfbifurcation for a practical value of the reactance is found and analyzed. Three groups of simulations are presented, time dependent wind speed, drop-clear terminal voltage, and a drop-clear case in reactance to show the bifurcation effect and thesystem's response to it.

In and near Chaco Canyon, New Mexico—the center of monumental ceremonial architecture of the Ancestral Puebloan culture—ancient peoples appear to have intentionally interrelated numerous small masonry structures on alignments to the major standstill moon. The structures include low-walled C-shaped, circular, and cairn configurations located on prominent positions near the tops of three mesas that form the south side of Chaco Canyon and mesas located beyond the canyon, with inter-site alignments spanning 5–15 km. Deposits of turquoise and other offerings at these small sites, and their similarity with later Puebloan features, suggest their use as shrines. Geographic information system analysis of the spatial distribution of these sites—with precise geodetic coordinates determined by the National Oceanic and Atmospheric Administration’s National Geodetic Survey—shows clustering of their interrelationships along azimuths to the rising and setting moon at its major standstill. Previous extensive investigation by the Solstice Project, with geodetic support by the National Geodetic Survey, documented the Chacoans’ commemoration of the lunar standstill cycle at the Sun Dagger petroglyph site on Fajada Butte and in the wall alignments and inter-building relationships of numerous Chaco Great Houses. Other research documented the relationship of the Chacoan Great House of Chimney Rock, Colorado, to the major lunar standstill. Our findings of the inter-shrine-site alignments to the major standstill moon provide significant evidence for a hitherto undocumented small scale of lunar astronomical expression of the Chaco culture. The placement of these shrines also appears to possibly have marked a correspondence between the topographic trajectory of Chaco Canyon and the alignment to the moon at its major standstill, suggesting a specific effort to integrate Chaco’s land formations with celestial patterns. These preliminary findings are part of a study in progress of cosmographic expressions throughout the Chacoan cultural region.

In this paper, the model of a type-3 DFAG/DFIG wind turbine generator is considered at higher wind speeds with the pitch control activated. The main blocks of the model taken from the literature are described and translated into a system of differential equations with algebraic constraints. Eigenvalues and steady states of the model are presented with the main focus being the sensitivity analysis of state variables and eigenvalues to the parameters, and how the parameters affect the steady states. Results for sensitivities to a single parameter and two parameters are provided along with a simulation of the dynamics for time-varying wind speed.

Fault intersections are the locus of hot spring activity and Carlin-type gold mineralization within the Basin and Range, USA. Analytical and numerical solutions to Stokes equation suggest that peak fluid velocities at fault intersections increase between 20% and 47% when fracture apertures have identical widths but increase by only about 1% and 8% when aperture widths vary by a factor of 2. This suggests that fault zone intersections must have enlarged apertures. Three-dimensional finite element models that consider intersecting 10to 20-m wide fault planes resulted in hot spring activity being preferentially located at fault zone intersections when fault zones were assigned identical permeabilities. We found that the onset of convection at the intersections of the fault zones occurred in our hydrothermal model over a narrow permeability range between 5 · 10 and 7 · 10 m. Relatively high vertical fluid velocities (0.3–3 m year) extended away from the fault intersections for about 0.5–1.5 km. For the boundary conditions and fault plane dimensions used, peak discharge temperatures of 112 C at the water table occurred with an intermediate fault zone permeability of 5 · 10 m. When fault plane permeability differed by a factor of 2 or more, the locus of hot spring activity shifted away from the intersections. However, increasing the permeability at the core of the fault plane intersection by 40% shifted the discharge back to the intersections. When aquifer units were assigned a permeability value equal to those of the fault planes, convective rolls developed that extend about 3 km laterally along the fault plane and into the

The relationship between MRI findings (i.e., subcortical hyperintensities; SH, whole brain volume) and the cognitive dysfunction of vascular dementia (VaD) was examined. Participants included 24 persons that met NINDS-AIREN criteria for VaD (MMSE = 19.9 ± 4.2) and underwent comprehensive neuropsychological assessment and MRI brain imaging. The volume of subcortical hyperintensities (SH) was strongly associated with executive–psychomotor performance, but not with performance across other cognitive domains or global cognitive functional level. Conversely, WBV was strongly associated with global cognitive functioning and performance across most cognitive domains (memory, language, visual integration), but not with executive–psychomotor functioning. The failure of SH to account for either the global dementia evident in these VaD patients or impairments across most cognitive domains suggests that deep subcortical white matter disease may only indirectly contribute to the global cognitive dysfunction of VaD. That WBV emerged as a stronger correlate of dementia raises further questions regarding the cerebral mechanisms that contribute to the development of VaD. (JINS, 2002, 8, 743–752.)