bluuebunny/crossref_metadata_2025 huggingface dataset:
Stribeck Curve Analysis of Temporomandibular Joint Condylar Cartilage and Disc
Authors: Middendorf Jill M. , Albahrani Shaden A. , Bonassar Lawrence J.
Published: October 2019

Temporomandibular joint (TMJ) diseases such as osteoarthritis and disc displacement have no permanent treatment options, but lubrication therapies, used in other joints, could be an effective alternative. However, the healthy TMJ contains fibrocartilage, not hyaline cartilage as is found in other joints. As such, the effect of lubrication therapies in the TMJ is unknown. Additionally, only a few studies have characterized the friction coefficient of the healthy TMJ. Like other cartilaginous tissues, the mandibular condyles and discs are subject to changes in friction coefficient due to fluid pressurization. In addition, the friction coefficients of the inferior joint space of the TMJ are affected by the sliding direction and anatomic location. However, these previous findings have not been able to identify how all three of these parameters (anatomic location, sliding direction, and fluid pressurization) influence changes in friction coefficient. This study used Stribeck curves to identify differences in the friction coefficients of mandibular condyles and discs based on anatomic location, sliding direction, and amount of fluid pressurization (friction mode). Friction coefficients were measured using a cartilage on glass tribometer. Both mandibular condyle and disc friction coefficients were well described by Stribeck curves (R2 range 0.87–0.97; p < 0.0001). These curves changed based on anatomic location (Δμ ∼ 0.05), but very few differences in friction coefficients were observed based on sliding direction. Mandibular condyles had similar boundary mode and elastoviscous mode friction coefficients to the TMJ disc (μmin ∼ 0.009 to 0.19) and both were lower than hyaline cartilage in other joints (e.g., knee, ankle, etc.). The observed differences here indicate that the surface characteristics of each anatomic region cause differences in friction coefficients.
Effect of Deterministic and Continuous Design Space Resolution on Multiple-Objective Combustor Optimization
Authors: Briones Alejandro M. , Rumpfkeil Markus P. , Thomas Nathan R. , Rankin Brent A.
Published: October 2019

Supervised machine learning is used to classify a continuous and deterministic design space into a nondominated Pareto frontier and dominated design points. The effect of the initial training data quantity on the Pareto frontier and output parameter sensitivity is explored. The study is performed with the optimization of a subsonic small-scale cavity-stabilized combustor. A 3D geometry is created and parameterized using computer aided design (CAD) that is combined with a software for meshing, which automatically transfers grids and boundary conditions to the solver and postprocessing tool. Steady, compressible three-dimensional simulations are conducted employing a multiphase Realizable k–ε Reynolds-averaged Navier–Stokes (RANS) physics with an adiabatic flamelet progress variable (FPV) model. The near-wall turbulence modeling is computed with scalable wall functions (SWFs). For each computational fluid dynamics (CFD) simulation, four levels of adaptive mesh refinement (AMR) are utilized on the original cut-cell grid. There are 15 geometrical input parameters and three output parameters, viz., a pattern factor proxy, a combustion efficiency proxy, and total pressure loss (TPL). Three times the number of input parameters plus one (48) is necessary to yield an optimization independent of the initial sampling. This conclusion is drawn by examining and comparing the Pareto frontiers and global sensitivities. However, the latter provides a better metric. The relative influence of the input parameters on the outputs is assessed by Spearman's order-rank correlation and an active subspace analysis. Some persistent geometric features for nondominated designs are also discussed.
Exact Nonlinear Dynamic Analysis of a Beam With a Nonlinear Vibration Absorber and With Various Boundary Conditions
Authors: Bukhari Mohammad , Barry Oumar
Published: October 2019

We study the nonlinear vibration of a beam with an attached grounded and ungrounded nonlinear vibration absorber (NVA) using the exact natural frequencies and mode shapes of the loaded beam. The nonlinearity in the beam is due to midplane stretching and that in the NVA is of cubic stiffness nonlinearity. We consider various boundary conditions and derive their closed-form characteristic equations and mode shapes. The method of multiple scales (MMS) is directly applied to the nonlinear partial differential equations of motion to obtain explicit expressions of the nonlinear frequency, modulation, and loci of the saddle-node bifurcation equations. Our analytical approach is validated using direct numerical simulation. Parametric studies demonstrate that the performance of the NVA does not only depend on its key design variables and location, but also on the boundary conditions, midplane stretching of the beam, and type of configuration (i.e., grounded NVA versus ungrounded NVA). Our analysis also indicates that the use of common approach such as employing approximate modes in estimating the nonlinear response of a loaded beam produces significant error (i.e., up to 1200% in some case). These observations suggest that the exact modes shape and natural frequencies are required for a precise investigation of the nonlinear dynamic of loaded beams. These findings could contribute to the design improvement of NVAs, microelectromechanical systems (MEMS), energy harvesters, and metastructures.
A Unifying Framework for Probabilistic Validation Metrics
Authors: Gardner Paul , Lord Charles , Barthorpe Robert J.
Published: October 2019

Probabilistic modeling methods are increasingly being employed in engineering applications. These approaches make inferences about the distribution for output quantities of interest. A challenge in applying probabilistic computer models (simulators) is validating output distributions against samples from observational data. An ideal validation metric is one that intuitively provides information on key differences between the simulator output and observational distributions, such as statistical distances/divergences. Within the literature, only a small set of statistical distances/divergences have been utilized for this task; often selected based on user experience and without reference to the wider variety available. As a result, this paper offers a unifying framework of statistical distances/divergences, categorizing those implemented within the literature, providing a greater understanding of their benefits, and offering new potential measures as validation metrics. In this paper, two families of measures for quantifying differences between distributions, that encompass the existing statistical distances/divergences within the literature, are analyzed: f-divergence and integral probability metrics (IPMs). Specific measures from these families are highlighted, providing an assessment of current and new validation metrics, with a discussion of their merits in determining simulator adequacy, offering validation metrics with greater sensitivity in quantifying differences across the range of probability mass.
Postoperation Dose Rate Estimates for the Very-Small, Long-Life, Modular Reactor
Authors: Palomino Luis M. , El-Genk Mohamed S. , Schriener Timothy M.
Published: October 2019

The very-small, long-life, modular (VSLLIM) nuclear reactor generates 1.0–10 MWth, for ∼92 and 5.8 full power years (FPY), respectively, without refueling. This factory fabricated, assembled, and sealed reactor is cooled by natural circulation of in-vessel liquid sodium (Na). It offers redundant control and passive operation and decay heat removal features. The VSLLIM reactor, together with other plant components for generating electricity using open Brayton cycle, is deployable on a portable platform. Alternatively, multiple units could be installed at a site and use high thermal efficiency Rankine or supercritical CO2 cycles for electricity generation. Extensive analyses are performed to estimate postoperation external biological dose rate and the storage time required on-site for this dose rate to decrease to or below the U.S. federal transportation limit (0.2 rem/h or 2 mSv/h) for safe handling, removal, and replacement with a new unit loaded with fresh fuel. Results show that gamma photons emission from the uranium nitride (UN) fuel and the activated HT-9 steel cladding for the UN fuel rods, the core structure, and the reactor primary vessel, is a major contributor to the radiological source term, and the external biological dose rate estimates. After operating at 10 MWth for 5.8 FPY, using 6 cm thick lead shielding of the reactor guard vessel, decreases the postoperation external biological dose rate to be in compliance with the federal limit, only after∼ 103 days of postoperation on-site storage.
Proof of Concept of a Surrogate High-Adhesion Medical Tape Using Photo-Thermal Release for Rapid and Less Painful Removal
Authors: Lim Saniel D. , Svanevik Carl C. , Fauver Mark E. , Nelson Leonard Y. , Taroc Ann-Marie , Emery Ashley F. , Seibel Eric J.
Published: October 2019

Medical tapes often hold critical devices to the skin so having high adhesion for the lifespan of this product is of great importance. However, the removal process is challenging for caregivers and patients alike, often a painful process that can cause medical adhesive-related skin injury (MARSI). By using an industrial thermally sensitive tape, a surrogate photosensitive tape was developed that switched from the equivalent of high-adhesion medical tape to low-adhesion medical tape. This resulted in an 86% reduction in the average peel strength when heated from 45 to 55 °C using a custom test apparatus. To photo-release the prototype tape (PT), a near-infrared (NIR) absorbing layer was painted on the visibly clear thermal-sensitive tape and an NIR optical wand using 15-LEDs (940 nm) with thermal feedback control was designed and tested. Preliminary performance of photo-to-thermal conversion was numerically modeled with transient results matching experimental measurements with 96.8% correspondence. Using the verified energy conversion model of the surrogate photosensitive tape, a new NIR optical wand was designed for rapid and noncontact release of a future medical tape at 10 deg lower than the release temperature (RTemp) of the custom adhesive, called UnTape. Numerical simulations compared to the thermal skin pain threshold of 45 °C predicts photo-release within 1.1 s of NIR exposure (85.5% absorption in PT at < 1.3 W/cm2). The unique properties of the multifunctional UnTape system (tape and portable NIR wand) may allow even stronger skin adhesion for critical medical devices while concurrently reducing the risk of MARSI upon photo release and easy removal.
Analysis of the Evolution of the Structure of a Surface With Pyramidal Asperities in Contact With a Hard and Smooth Plane
Authors: Bourassia Bensaad , Brahim Bourouga
Published: October 2019

This research deals with the evolution of the structure of the sapphire–brass interface due to the variation of contact pressure. This evolution primarily affects the essential parameters that govern the thermal contact resistance (TCR), namely, the contact point density N, the ratio of real area of contact S*, and the distance d separating the median contact planes. The combination of three measurement techniques, namely, profilometry, imaging, and mechanical characterization, was used for the purpose of investigating the structural variation of the interface. Alternatively, the TCR, which prevails at the interface, was estimated. Thus, the object of our study is to propose an original and new experimental approach allowing at the same time the precise measurement of the TCR and the estimate of the contact parameters of the interface studied constituting input data to the theoretical models of TCR. The estimated values given by these last are then compared with those measured. Through this approach, we try to open new ways of experimentation that would tend to reinforce the effort of TCR modeling. The results obtained showed that the roughness parameters Ra and Rq are independent of loading. The roughness Rp, which is considered equal to d, is sensitive to loading and has the same decreasing behavior under the effect of loading. The determination of S*, using the hardness testing, is even more relevant when the effective hardness Hc is considered. Analysis of data for the estimation of the TCR shows that the comparisons with the reference model (Bardon) attest to the relevance of our approach.
Multifidelity Analysis of Acoustic Streaming in Forced Convection Heat Transfer
Authors: Agarwal Tapish , Rahbari Iman , Saavedra Jorge , Paniagua Guillermo , Cukurel Beni
Published: October 2019

This research effort is related to the detailed analysis of the temporal evolution of thermal boundary layer(s) under periodic excitations. In the presence of oscillations, the nonlinear interaction leads to the formation of secondary flows, commonly known as acoustic streaming. However, the small spatial scales and the inherent unsteady nature of streaming have presented challenges for prior numerical investigations. In order to address this void in numerical framework, the development of a three-tier numerical approach is presented. As a first layer of fidelity, a laminar model is developed for fluctuations and streaming flow calculations in laminar flows subjected to traveling wave disturbances. At the next level of fidelity, two-dimensional (2D) U-RANS simulations are conducted across both laminar and turbulent flow regimes. This is geared toward extending the parameter space obtained from laminar model to turbulent flow conditions. As the third level of fidelity, temporally and spatially resolved direct numerical simulation (DNS) simulations are conducted to simulate the application relevant compressible flow environment. The exemplary findings indicate that in certain parameter space, both enhancement and reduction in heat transfer can be obtained through acoustic streaming. Moreover, the extent of heat transfer modulations is greater than alterations in wall shear, thereby surpassing Reynolds analogy.
Analytic Modeling of Heat Transfer to Vertical Dense Granular Flows
Authors: Watkins Megan F. , Chilamkurti Yesaswi N. , Gould Richard D.
Published: October 2019

The high packing fractions of dense granular flows make them an attractive option as a heat transfer fluid or thermal energy storage medium for high temperature applications. Previous works studying the heat transfer to dense flows have identified an increased thermal resistance adjacent to the heated surface as a limiting factor in the heat transfer to a discrete particle flow. While models exist to estimate the heat transfer to dense flows, no physics-based model describing the heat transfer in the near-wall layer is found; this is the focus of the present study. Discrete element method (DEM) simulations were used to examine the near-wall flow characteristics, identifying how parameters such as the near-wall packing fraction and number of particle-wall contacts may affect the heat transfer from the wall. A correlation to describe the effective thermal conductivity (ETC) of the wall-adjacent layer (with thickness of a particle radius) was derived based on parallel thermal resistances representing the heat transfer to particles in contact with the wall, particles not in contact with the wall, and void spaces. Empirical correlations based on DEM results were developed to estimate the near-wall packing fraction and number of particle-wall contacts. The contribution from radiation was also incorporated using a simple enclosure analysis. The ETC correlation was validated by incorporating it into dense flow models for chute flows and cylindrical flows and comparing with the experimental data for each.
A Mathematical Analysis of Directional Solidification of Aqueous Solutions
Authors: Ukpai Gideon , Rubinsky Boris
Published: October 2019

Horizontal directional solidification techniques have been broadly utilized for the freezing of biological matter under conditions in which the freezing rate during solidification must be controlled and known. Directional solidification is used for diverse applications such as fundamental research on freezing of biological materials, cryopreservation of biological matter, and tissue engineering. This study is motivated by our intent to use directional solidification as a simplified model for the study of three-dimensional (3D) cryoprinting. In evaluating directional solidification in the context of 3D cryoprinting, we realized that current mathematical models of directional solidification are not adequately representative for this purpose, because they are simplified and one-dimensional (1D). Here, we introduce an experimentally verified and more representative two-dimensional (2D) mathematical model of directional solidification that can aid in the fundamental study of freezing of biological matter, in particular during 3D cryoprinting. The mathematical model was used to develop correlations between the freezing rates that a layer of an aqueous solution experiences during directional solidification and the various design parameters such as thickness of the sample and temperature gradients in the substrate. Results show that the freezing rates can be higher than those suggested by the previously used simplified 1D mathematical models. The results can be used for developing simplified models of 3D cryoprinting. In addition, the results suggest that many experimental studies on directional solidification of aqueous solutions and biological matter may require readjustment of analysis, in view of these findings.
Toward Automated Vehicle Control Beyond the Stability Limits: Drifting Along a General Path
Authors: Goh Jonathan Y. , Goel Tushar , Christian Gerdes J.
Published: October 2019

Professional drivers in drifting competitions demonstrate accurate control over a car's position and sideslip while operating in an open-loop unstable region of state-space. Could similar approaches help autonomous cars contend with excursions past the stable handling limits, thereby improving overall safety outcomes? As a first step toward answering that question, this paper presents a novel controller framework for automated drifting along a path. The controller is derived for the general case, without reference to a nearby equilibrium point. This leads to the physically insightful result that one can use the rotation rate of the vehicle's velocity vector to track the path, while simultaneously using the yaw acceleration to stabilize sideslip. Nonlinear model inversion, in concert with low-level wheelspeed control, is then used to achieve these required state derivatives over a broad range of conditions. Experiments on MARTY, a modified 1981 DMC DeLorean, demonstrate excellent tracking of a path with varying curvature, speed, and sideslip. Comparisons to a test run without wheelspeed control highlight the importance of accounting for the rear saturated-tire wheelspeed dynamics.
Design and Analysis of a Swashplate Control System for an Asymmetric Axial Piston Pump
Authors: He Wei , Huang Jia-Hai , Hao Hui-Min , Quan Long , Ji Shuai-xu , Zhao Bin
Published: October 2019

Based on the previously developed fixed-displacement asymmetric axial piston pump, a variable displacement asymmetric axial piston pump (VDAAPP) with three independent suction/delivery ports is proposed. A basic linear model of VDAAPP is established to get open-loop bode diagram. Based on open-loop Bode diagram features and design requirements, P-controller is determined for VDAAPP. Then VDAAPP's performance is investigated by advanced modeling environment for performing simulations of engineering systems (AMESim) and automatic dynamic analysis of mechanical systems (ADAMS) joint simulation, and some key design parameters are obtained. Next, a VDAAPP prototype with a maximum displacement of 40 cc/rev is designed and manufactured, ratio of flow rates at ports A, B and T is 1:0.6:0.4. Due to hard limitations of the test bench, the performance only under the conditions of the opposite passive loads is tested. Preliminary test results indicate that VDAAPP prototype works normally and meets the design requirements for flow ratio, and the maximum rise time of the test pressure is about 0.32 s. However, due to special design of VDAAPP valve plate, the swash plate torque severely limits system dynamic response. Therefore, an improved swashplate control system based on asymmetric-valve-controlled asymmetric-piston scheme is presented as well, it is found to be an effective way to suppress the negative impact of swash plate torque on system dynamic performance. This provides a direction for the optimization of the swashplate control system for asymmetric axial piston pumps in the future.
Nonlinear Kalman Filtering With Expensive Forward Models Via Measure Change
Authors: Burrows Brian J. , Allaire Douglas
Published: October 2019

Filtering is a subset of a more general probabilistic estimation scheme for estimating the unobserved parameters from the observed measurements. For nonlinear, high speed applications, the extended Kalman filter (EKF) and the unscented Kalman filter (UKF) are common estimators; however, expensive and strongly nonlinear forward models remain a challenge. In this paper, a novel Kalman filtering algorithm for nonlinear systems is developed, where the numerical approximation is achieved via a change of measure. The accuracy is identical in the linear case and superior in two nonlinear test problems: a challenging 1D benchmarking problem and a 4D structural health monitoring problem. This increase in accuracy is achieved without the need for tuning parameters, rather relying on a more complete approximation of the underlying distributions than the Unscented Transform. In addition, when expensive forward models are used, we achieve a significant reduction in computational cost without resorting to model approximation.
Impact of a Plate on an Asymmetric Water Wedge
Authors: Wen Xueliang , Liu Peiqing , Qu Qiulin , Hu Tianxiang
Published: October 2019

The impacts of a plate on an asymmetric water wedge with constant and varying speeds are studied in this paper by considering the fluid to be incompressible, inviscid, and weightless; the effect of surface tension to be negligible; and the flow to be irrotational. A similarity solution for an impact with a constant speed is derived with the help of Wagner's function and the Schwarz–Christophel mapping technique and then numerically solved by employing an iterative method. An approximate solution is derived for the impact with a varying speed satisfying a power law in time based on the computational fluid dynamics (CFD) results with the volume of fluid (VOF) method. The approximate solution can provide an explicit expression for the pressure acting on the plate. The CFD validation shows that the pressure expression can also be applicable to other cases in which the speed of the plate is not a power law in time.
An Area-Depth Approximation Model of Microdrilling on High-Density Polyethylene Soft Films Using Pulsed Laser Ablation
Authors: Ravi-Kumar Sandeep , Zhang Xiao , Lies Benjamin , Jiang Liangkui , Qin Hantang
Published: October 2019

Microdrilling based on laser ablation has been widely applied for manufacturing micro-/nanofeatures on different materials as a noncontact thermal removal approach. It has the advantages of high aspect ratio manufacturing capability and reduced surface damage. However, laser ablation is a complicated process that is challenging to model. In this paper, a standardized modeling procedure was demonstrated to predict the area and depth of laser ablation based on experimental study and simulation validation. A case study was conducted where microdrilling of high-density polyethylene (HDPE) was investigated using a 1064 nm nanosecond pulsed laser. Blind microholes were fabricated on the HDPE samples by ablating under different laser powers and numbers of pulses. Gain factors were defined and determined by the experimental data. A quantitative area-depth approximation model was formulated based on the gain factors. A comparison of the measured and the simulated results of microholes presented average 96.5% accuracy for the area and 85.7% for the depth. This research provided a simple but effective approach to predict dimensions of microholes on various substrates using laser ablation under different laser powers and the numbers of pulses, which could pave the way for development and modeling of laser ablation on polymers.
New records of water mites (Acari: Hydrachnidia) from the Western Himalaya and description of three new species from Asia
Authors: Pešić Vladimir , Smit Harry , Bahuguna Pankaj
Published: October 2019

New material of water mites (Acari: Hydrachnidia) from the Uttarakhand State of India is reported, including a new species, Kongsbergia indica sp. nov. (Aturidae), and new records of the species Sperchon garhwalensis Kumar, Kumar & Pešić, 2007, Sperchon indicus Kumar, Kumar & Pešić, 2007, and Atractides indicus Pešić & Smit, 2007. Moreover, in the light of the newly discovered male of Torrenticola turkestanica (Sokolow, 1926), populations from South Korea and Thailand formerly assigned to the latter species are here attributed to two new species, i.e., T. wonchoeli sp. nov. and T. rangareddyi sp. nov., respectively.
A new genus, new species and a new record of the family Pygmephoridae (Acari: Heterostigmata) associated with Microcerotermes  parvus (Haviland) (Isoptera: Termitidae) from South Africa

Authors: Khaustov Alexander A. , Hugo-Coetzee Elizabeth A. , Ermilov Sergey G.
Published: October 2019

A new genus and species of termitophilous pygmephorid mites, Pseudoluciaphorus tuberosus gen. nov. and sp. nov. (Acari: Prostigmata: Pygmephoridae), associated with termites, Microcerotermes parvus (Haviland) (Isoptera: Termitidae) are described from South Africa. Luciaphorus perniciosus Rack is recorded from Africa for the first time. Images of phoretic females of L. perniciosus phoretic on workers and soldiers of Microcerotermes parvus are provided.
Butcher Ridge igneous complex: A glassy layered silicic magma distribution center in the Ferrar large igneous province, Antarctica
Authors: Nelson Demian A. , Cottle John M. , Schoene Blair
Published: October 2019

The Butcher Ridge igneous complex, Antarctica, is an ∼6000 km3 hypabyssal silicic intrusion containing rhythmically layered glassy rocks. Baddeleyite U-Pb geochronologic analysis on a sample of the Butcher Ridge igneous complex yielded an age of ca. 182.4 Ma, which confirms that it was emplaced synchronously with the Ferrar large igneous province. Rocks of the Butcher Ridge igneous complex vary from basaltic andesite to rhyolite, and so the inferred volume of the Butcher Ridge igneous complex makes it the most voluminous silicic component of the Ferrar large igneous province. Major-element, trace-element, and isotopic data combined with binary mixing, assimilation-fractional crystallization (AFC), and energy-constrained AFC models are consistent with formation of Butcher Ridge igneous complex silicic rocks by contamination of mafic Ferrar parental magma(s) with local Paleozoic plutonic basement rocks. Field and petrographic observations and evidence for alkali ion exchange suggest that the kilometer-long, meter-thick enigmatic rhythmic layering formed as a result of secondary hydration and devitrification of volcanic glass along parallel fracture networks. The regularity and scale of fracturing/layering imply a thermally driven process that occurred during shallow emplacement and supercooling of the intrusion in the upper crust. We suggest that layering observed in the Butcher Ridge igneous complex is analogous to that reported from terrestrial and Martian cryptodomes, and therefore it is an ideal locality at which to study layering processes in igneous bodies.
A randomized comparison between Accuro and palpation-guided spinal anesthesia for obese patients undergoing orthopedic surgery
Authors: Ghisi Daniela , Tomasi Marco , Giannone Sandra , Luppi Alessandra , Aurini Lucia , Toccaceli Letizia , Benazzo Andrea , Bonarelli Stefano
Published: October 2019

Background

Although obese patients benefit from neuraxial anesthesia, technical difficulties often discourage its use. The current randomized trial compared Accuro, a hand-held, battery-operated ultrasound (US) device, and conventional palpation for spinal anesthesia in obese patients undergoing orthopedic surgery. We hypothesized that Accuro would decrease the number of needle redirections.

Methods

We enrolled 130 men and women with a body mass index ≥30 kg/m2, scheduled for lower limb surgery under spinal block. Patients were randomized either to the Control group (group C: spinal block after palpation of cutaneous landmarks) or to the Accuro group (group A: preprocedural US scan with Accuro to identify the needle insertion point). The procedural time, the number of skin passes and of needle redirections, the occurrence of failure and adverse events were recorded.

Results

Ninety-nine patients completed the study. Patients in group Accuro showed a median (IQR) number of redirections of 3 (0–9) and a median (IQR) number of needle passes through the skin of 1 (1-2) versus 6 (1-16) and 1 (1-3), respectively, in group Control (p=0.008, p=0.019). The performance time was 558±232 s in group Accuro versus 348±255 s in group Control (p<0.001). There were no intergroup differences in terms of failed blocks and adverse events.

Conclusions

The use of Accuro reduced the number of needle redirections and passes through the skin when performing spinal anesthesia, but required a longer procedural time.

Trial registration number

ClinicalTrials.gov registry (NCT03075488).
Ultrasound-guided L5 dorsal ramus block: validation of a novel technique
Authors: Etheridge John-Paul B , De Villiers Frederick , Venter Jan , Squire Pam , Farnquist Brenda , Finlayson Roderick J
Published: October 2019

Background

Although the value of ultrasound-guided (USG) lumbar medial branch blocks (MBB) has previously been examined in several clinical trials, blocking the L5 dorsal ramus (DR) remains a technical challenge and we sought to examine the accuracy of a novel technique targeting this level.

Methods

In this prospective cohort study, 115 patients scheduled for an L4 MBB and L5 DR block underwent an ultrasound scan to assess their lower spine sonoanatomy. Subjects in whom the necessary landmarks could be visualized underwent a USG L5 DR block using a pivot technique, which involved redirecting a needle from its position on the L5 transverse process after an L4 MBB. Success was determined by a blinded observer who examined the contrast distribution on postprocedural X-ray images. In addition to the final needle position, performance time, the number of needle passes, and any complication were recorded.

Results

A total of 100 patients had a USG block and 15 patients (13%) were excluded because of poor landmark visibility. The latter group presented a significantly higher body mass index (38.90±7.50 vs 26.31±4.25 kg/m2, p=0.004). A total of five failures were noted (95% success rate), this included three patients with transitional anatomy in whom needles were placed at the wrong level and two cases of incomplete contrast coverage possibly related to the partial intravascular injection. Performance time was 153.93±41.56 s and the median number of needle passes was 2 (range 4). No significant complications were noted.

Conclusion

The pivot technique provides a reliable approach for USG L5 DR ramus blocks.

Trial registration number

NCT03805906
Benign juvenile focal epilepsy in a captive Iberian lynx (Lynx pardinus)
Authors: Mínguez Juan J , Martinez Fernando , Vargas Astrid , Wessmann Annette , Lorenzo Valentina
Published: October 2019

An 8‐week‐old intact male lynx cub (Lynx pardinus) from a captive breeding colony was presented with a 2‐day history of cluster seizures. There was no history of intoxication. Physical and neurological examinations were normal. Complete blood profile, infectious diseases panel, MRI of the brain and cerebrospinal fluid analysis were unremarkable. A diagnosis of suspected idiopathic epilepsy was made. The lynx cub was treated with increasing doses of phenobarbital and seizure activity stopped within 28 days. After 23 seizure‐free months, phenobarbital was tapered over 4 months and finally discontinued. No further seizures were observed during the follow‐up period of 8 years. Given the early onset followed by rapid and maintained remission, seizure semiology and the lack of underlying disease, a presumptive diagnosis of benign focal epilepsy similar to benign childhood focal epilepsies as described in human medicine is postulated.
Geant4-based electromagnetic background model for the CRESST dark matter experiment
Authors: Abdelhameed A. H. , Angloher G. , Bauer P. , Bento A. , Bertoldo E. , Breier R. , Bucci C. , Canonica L. , D’Addabbo A. , Lorenzo S. Di , Erb A. , Feilitzsch F. v. , Iachellini N. Ferreiro , Fichtinger S. , Fuss A. , Gorla P. , Hauff D. , Jes̆kovský M. , Jochum J. , Kaizer J. , Kinast A. , Kluck H. , Kraus H. , Langenkämper A. , Mancuso M. , Mokina V. , Mondragón E. , Olmi M. , Ortmann T. , Pagliarone C. , Palus̆ová V. , Pattavina L. , Petricca F. , Potzel W. , Povinec P. , Pröbst F. , Reindl F. , Rothe J. , Schäffner K. , Schieck J. , Schipperges V. , Schmiedmayer D. , Schönert S. , Schwertner C. , Stahlberg M. , Stodolsky L. , Strandhagen C. , Strauss R. , Türkoğlu C. , Usherov I. , Willers M. , Zema V. , Zeman J.
Published: October 2019

The CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) dark matter search experiment aims for the detection of dark matter particles via elastic scattering off nuclei in $$\mathrm {CaWO_4}$$CaWO4 crystals. To understand the CRESST electromagnetic background due to the bulk contamination in the employed materials, a model based on Monte Carlo simulations was developed using the Geant4 simulation toolkit. The results of the simulation are applied to the TUM40 detector module of CRESST-II phase 2. We are able to explain up to $$(68 \pm 16)\,\mathrm {\%}$$(68±16)% of the electromagnetic background in the energy range between 1 and $$40\,\mathrm {keV}$$40keV.
Casimir effect in an axially symmetric spacetime with unparticles
Authors: Bezerra V. B. , Muniz C. R. , Vieira H. S.
Published: October 2019

We investigate the Casimir effect of the massless scalar field in a cavity formed by ideal parallel plates in the spacetime generated by a rotating axially symmetric distribution of vector or scalar (tensor) unparticles, around which the plates orbit. The presence of the unparticles is incorporated to the background by means of a correction to the Kerr solution of the Einstein equations, in which the characteristic length and the scale dimension associated to the unparticle theory are taken into account. We show that the Casimir energy density depends also on these parameters. The analysis of the “ungravity” limit for the Casimir energy density, in which the characteristic length is very large in comparison to the horizon radius, is made, too. At zero temperature, we show that such a limit implies the instability of the system, since the Casimir energy density becomes an imaginary quantity. The general result is compared to the current terrestrial experiments of the Casimir effect. Thermal corrections also are investigated and the ungravity limit again examined, with the aforementioned instability disappearing at high temperatures.
“Welcome to Jamrock": poéticas e políticas Rastafari nas ruas de Kingston
Authors: Araújo Felipe Neis
Published: October 2019

Neste ensaio reflito sobre os modos como Rastas criam e recriam Kingston habitando-a com sua presença física, suas narrativas e seu léxico. A Kingston Rastafari é construídos sobre diversas camadas semânticas e políticas, e a questão dos topônimos emergiu nas mais diversas interações que tive com meus interlocutores ao longo de meu trabalho de campo. Para além da toponímia rastafari, reflito também sua presença; seus corpos marcados por índices de pertencimento ao Movimento Rastafari; as decorações de muros e casas com cores e motivos rastafari, as narrativas de eventos ocorridos em certos locais. Explorar os modos de ocupação de Kingston pelos rastas é uma forma de analisar como diferentes pessoas e coletivos se posicionam e agem em relação à memória social, cidadania, utilização e acesso aos espaços públicos, acesso a direitos e reparação pelos ciclos de violência estatal aos quais foram submetidos ao longo da história.
Uma paciência selvagem trouxe-me até aqui: escrita em processo sobre processos de construção de lesbianidades através de escrita, circulação de textos e leitura
Authors: Maia Carolina
Published: October 2019

O presente trabalho, formulado inicialmente como trabalho de conclusão de um curso sobre etnografia e textualidade, apresenta parte dos resultados de pesquisa de mestrado da autora sobre publicações lésbicas de caráter periódico no Brasil e sua construção e circulação através de redes de correspondência, criando espaços para elaboração identitária, experimentação de escrita e construção política. Aqui, discuto gênero e gênero textual (gender, genre), a partir de uma perspectiva pós-estruturalista. O texto é construído através de e-mails e uma carta escrita a mão, em uma proposta de emulação do gênero epistolar, tendo o devaneio e a digressão como uma das marcas textuais empregadas para tal e a impossibilidade de edição como impulso para uma criação incremental e fragmentária dos argumentos.
Corpo livre: body and art as means of activism in Sao Paulo
Authors: Santos Eduardo Faria
Published: October 2019

New forms of organizing social movements are debating the intersection of different social markers or axis of oppression, as gender, sexuality, class and race, problematizing sexual and gender norms. The collective A Revolta da Lâmpada, in São Paulo, Brazil, claims to be a platform with intersectional horizon, creating a common denominator – the free body – among different identity groups without the hierarchization of agendas and delegitimization of its exclusive spaces. Through the celebration of their bodies occupying public spaces, it uses diverse artistic expressions to do activism, what is being called artivism. The study highlights how the collective goes beyond the debate on identity politics and uses the intersectional inspiration together with the body – and its emotions – as site of resistance, celebration and means of exploring artistic forms of doing activism.
Filmação e representação: o audiovisual nas montagens de performance do batuque de Ponto Chique – MG
Authors: Ribeiro Pâmilla Vilas Boas Costa
Published: October 2019

O presente artigo discute como a produção de um filme com o batuque de Ponto Chique e outros grupos de batuques vizinhos, ligados pelo rio São Francisco, mobiliza processos sociais e estéticos, ou seja, como o filme, enquanto processo de produção e exibição, se insere nessa relação entre drama estético, drama social e drama ritual. A partir do diálogo com autores da teoria da performance, o ponto de partida é discutir categorias como representação, drama e montagem, compreendendo a filmação como a materialização desse espaço fluido onde se assenta a cultura batuqueira/vazanteira.  A partir do uso das imagens enquanto método etnográfico, o artigo busca refletir sobre as relações entre as montagens batuqueiras e as montagens do filme como ficção e fricção entre passado e presente. Opera-se com a hipótese de que os fragmentos do passado organizam o tempo fílmico e podem constituir uma temporalidade própria dos batuques.
A liberdade também passou por aqui: Cineground, memória de uma cinematografia queer dos anos 1970 em Portugal
Authors: Gonçalves Mariana
Published: October 2019

A Cineground (1975-78) foi uma produtora de cinema amador, fundada em pleno PREC pelo artista plástico Óscar Alves e pelo cineasta João Paulo Ferreira. Projeto também ele revolucionário pela abordagem de sexualidades ainda criminalizadas na década de 1960/70, mostrou que a verdadeira libertação da sociedade teria de passar pela libertação do corpo individual. Esta cinematografia produzida em formato Super-8, e característica das condições sociais particulares deste tipo de circuito, abordou pela primeira vez no cinema português a temática gay, com a representação da vida dupla dos homossexuais (problemática do armário), e também queer, com a presença constante da personagem travesti. À discussão da performance travesti enquanto possibilidade de transgressão e desnaturalização de noções de género e identidade, segue-se uma reflexão sobre a representação e visibilidade das pessoas LGBT no cinema, no qual o Cineground, veículo de desobediência à ordem social e política da época, aparece como uma forma de artivismo.
Listas de artistas nunca são somente listas, versão 2.0
Authors: Vaitsman Marcia
Published: October 2019

Reflexão sobre trabalhos de artistas contemporâneas e suas obras, com caráter autonarrativo e autobiográfico, que contemplam a desorientação, a impermanência e a estrangeiridade, enfocando a atividade de fazer listas, catalogação, organização, arquivos, o interesse pelo alfabético, numérico, cartográfico e, por outro lado, o inclassificável, o que é cifrado, a desorientação e o et cetera. Traz o vídeo 10 delírios em 10 sutras (2017) e a lista 100 palavras que descrevem as imagens do deslocamento (2017) como exemplos, usados como instrumentos para entender suas próprias localidades e suas temporalidades, para abordar aspectos de uma situação ético-estética, transitória, do deslocamento.
festival religioso Ratha Yatra desfila no espaço público da “Lisboa intercultural”
Authors: Baldelli Debora
Published: October 2019

Este ensaio visual acompanha o desfile da segunda edição do festival religioso Ratha Yatra em Lisboa, organizado pela ISKCON Lisboa (Associação Internacional para a Consciência de Krishna) desde 2016. O Ratha Yatra Lisboa tem como base a proposta de unir diferentes grupos, entidades e comunidades de imigrantes na sua organização para uma performance coletiva pelas ruas do centro da cidade, realizando uma espécie de desfile de cidadania. Procuro enfatizar a importância das performances associadas à música e à dança no espaço público para a compreensão das experiências transnacionais.
Schneider, Arnd. 2017. Alternative art and anthropology: global encounters. London: Bloomsbury Academic.
Authors: Lappicy Paola
Published: October 2019

O livro Alternative art and anthropology: global encounters, editado por Arnd Schneider, traz uma conversa entre antropólogos, artistas, etnógrafos e curadores de fora do eixo euro-americano, que discutem as suas experiências antropológicas na arte contemporânea. Entre artigos, entrevistas e imagens de autores de diversos lugares do mundo, Schneider reitera a proposta de uma conversa global, que amplie o debate entre antropologia e arte contemporânea, até recentemente uma discussão metropolitana centrada num eixo ocidental. O campo da antropologia foi dominado por discussões sobretudo ocidentais acerca de arte e antropologia. O livro propõe uma descentralização desse debate, por meio da leitura de outras experiências que há pouco tempo não estavam no eixo de discussão.
Sylvia Caiuby Novaes (Org.). Entre arte e ciência: a fotografia na antropologia. São Paulo: Edusp, 2015, 224p.
Authors: Bruno Fabiana
Published: October 2019

A contarmos da primeira metade do século XIX, as histórias da antropologia e da fotografia mereceram capítulos vinculados, que atestam uma relação de proximidade ao longo de suas trajetórias. Nos dias atuais, considerando-se o universo de saturação do mundo das imagens, referenciado por muitos autores como “pós-fotográfico”, à guisa das confidências entre fotografia e antropologia, o que se subscreve é um cenário de reflexões críticas sobre “os usos” e “o pensamento” das imagens fotográficas em suas perspectivas antropológicas. Nesse cenário, emerge também um arco de problematizações acerca de um conhecimento próprio das imagens e indaga-se sobre qual é o lugar das imagens e o que queremos delas.
SEM study of planktonic chlorophytes from the aquatic habitat of the Indian Sundarbans and their conservation status
Authors: Satpati Gour Gopal , Pal Ruma
Published: October 2019

Scanning electron microscopy (SEM) is the most modern technique for plankton research.  The present paper deals with the taxonomy and morphology of some rare and endangered planktonic chlorophytes in relation to scanning electron microscopy.  Water samples from the distinct water body of the Sundarbans have been concentrated and examined by scanning electron microscopy.  A total of 45 species, of which 17 species of Scenedesmaceae, 10 species each of Hydrodictyaceae and Desmidiaceae, five species of Chlorococcaceae, two species of Selenastraceae and only one species of Chlorellaceae were recorded from the study site.  Some species were recorded as new and rare from the study area.  About 18 species including nine extremely rare, seven occasional, six frequent, four sporadic and one abundant was recorded in the present study.  A detailed taxonomic description with line drawings is also included in the present communication.
Diversity of parasitic Hymenoptera in three rice-growing tracts of Tamil Nadu, India
Authors: Daniel Johnson Alfred , Ramaraju Kunchithapatham
Published: October 2019

Parasitic hymenoptera play a vital role in rice ecosystems as biocontrol agents of pests.  Surveys were conducted from August 2015 to January 2016 in three rice growing zones in Tamil Nadu: western zone, Cauvery Delta zone, and high rainfall zone.  A total of 3,151 parasitic hymenoptera were collected, of which 1,349 were collected from high rainfall zone, 1,082 from western zone, and 720 from Cauvery Delta zone.  Platygastridae, Ichneumonidae, and Braconidae were the most abundant families in all the three zones.  The species diversity, richness, evenness as well as beta diversity were computed for all three zones via Simpson’s, Shannon-Wiener and Margalef indices.  The results showed the high rainfall zone to be the most diverse and the Cauvery Delta zone the least diverse, but with more evenness.  Pairwise comparison of zones using Jaccard’s index showed 75–79% species similarity.
A new distribution record of the Pentagonal Sea Urchin Crab Echinoecus pentagonus (A. Milne-Edwards, 1879) (Decapoda: Brachyura: Pilumnidae) from the Andaman Islands, India
Authors: Meher Balakrishna , Thiruchitrambalam Ganesh
Published: October 2019

First time, a Sea Urchin Crab, Echinoecus pentagonus (A. Milne-Edwards, 1879) is recorded from the rocky intertidal region of the Andaman Islands. It is a symbiotic crab live with Sea Urchin. This species is recorded from the Lakshadweep and Nicobar Islands but still there is no record from mainland India. A detail description of the species with standard photographs and line diagrams is provided.
First records of the ghost moth genus Palpifer Hampson, [1893] (Lepidoptera: Hepialidae) from the Indian subcontinent south of the Himalaya
Authors: Karim Siyad A. , Grehan John R.
Published: October 2019

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