bluuebunny/crossref_metadata_2025 huggingface dataset:
An equivalent circuit model for electric conductive polymer composites
Authors: Zhang M Q , Zeng H M , Wang H F , Yao X
Published: January 2019

The electric properties of conductive high density polyethylene (HDPE) composites filled with carbon black were characterized by using frequency spectrum technique. The results show that with increasing carbon black content, the composites exhibit capacitive and inductive features, respectively. On the basis of the observed experimental phenomena, an equivalent inductance - capacitance - resistance (LCR) parallel serial circuit model is proposed
Experimental Modeling for the Compressive Strengthening Mechanism of an Al-Li / SiCp Composite
Authors: Boey F , Khor K A , Yang R , Sano T
Published: January 2019

The main strengthening mechanism for a SiCp / Al-Li alloy composite has been compared with a dislocation generation mechanism, under compression loading. Both higher volume fraction and a smaller SiC particle size was found to give higher increases in the compressive yield stress. However, the results also indicate that particulate reinforcement could only give limited increases in the yield stress.
Mechanical Properties and Corrosion Resistance of Al 6092-20 SiC(P) in Arabian Gulf Water and Neutral Sodium Chloride Solution
Authors: Ahmed Zaki , Aleem B.J. Abdul
Published: January 2019

Alloy 6092-20 SiC(P) a modification of Al-6013 shows higher mechanical strength than Al 6013 and Al 6061 reinforced with silicon carbide particulates and a good resistance to corrosion in highly corrosive Gulf water and neutral sodium chloride. The alloy in T4 temper showed a better resistance to corrosion than in 0 temper. Temper T4 represents a good combination of high mechanical strength and good corrosion resistance and appears to be a highly promising structural material with the capability to encounter marine environment.
Moisture Diffusion in T800/924C Carbon Fibre-Epoxy Laminates
Authors: Soutis C. , Turkmen D.
Published: January 2019

The objective of the present work is to evaluate the response of the T800/924C carbon fibreepoxy composite system (currently available for aerospace structural applications) in hot-wet environments. The weight gains, maximum moisture contents and diffusion coefficients of unidirectional and an orthotropic multidirectional laminate immersed in boiling water (accelerated ageing) are reported.
Mechanical Properties of Carbon Black-Filled Polymeric Concrete
Authors: Rejón L. , Ponce M.A. , Vazquez-Polo G. , Castaño V.M.
Published: January 2019

Polymeric concrete, a recently patented material for electrical insulators, was modified by using various amounts of monomer in the resins employed and by adding different concentrarions of carbon black. The results show that there exists an optimal carbon black content in terms of the mechanical performance.
Wear Status Estimation of Fiber Composite through Fractal Characterization of Wear Debris
Authors: Zhang Ming Qiu , Song Le , Zeng Han Min
Published: January 2019

As the product of mass loss during friction and wear, wear debris carries extensive information about the tribological process. By using fractal geometry, the authors of the present paper quantitatively characterize the morphologies of the wear particles of short carbon fiber reinforced polyetheretherketone (PEEK). The experimental results show that the fractal dimensions of the wear particles are closely correlated to the wear status of the bulk composites. Basing upon this investigation, one can predict or estimate wear conditions of tribological components made of polymer composites in practice.
Application of Composites to Civil Engineering Structures; Shear and Bending of Beam-to-Column Composite Sections
Authors: Gutierrez E. , Verzeletti G. , Galiotis C.
Published: January 2019

The structural integrity of a monolithic beam-column joint manufactured from glass-fibre pre-pregs was assessed under shear and bending. It was found that the higher content of shear reinforcement in the quasi-isotropic specimen the higher the stiffness of the joint. The main structural failure mechanism was associated with inter-laminar fissures developing internally at the radial beam-to-column transition.
Fabrication of Aramid Fiber Knitted Fabric Reinforced Polypropylene Composites
Authors: Cuong N.K. , Maekawa Z.
Published: January 2019

In this paper, the effects of fabrication conditions on mechanical properties of aramid fiber knitted fabric reinforced thermoplastic polypropylene composites have been investigated. Composite laminates were fabricated by variation of impregnation time and compression molding pressures. Impregnation of matrix resin into aramid fibers was identified by observing cross-sections of laminates. Tensile tests were carried out on samples cut from the laminates parallel to the wale and course directions. Tensile properties increased with increasing the impregnation time or the compression molding pressure. The tensile properties also display higher in wale direction than in course direction. SEM micrographs of fractured surfaces reveal poor adhesion between aramid fibers and polypropylene matrix.
Dielectric Dissipation of Fibre-modified Hydraulic Concretes
Authors: Hernández J.B. , Aguirre F.A. , Martínez J.L. , Caballero C. E. , Pérez-Rea L. , Castaño V.M.
Published: January 2019

Dielectric behavior of Portland cement-based concretes, modified with either polyester or polypropylene fibers was studied by measuring their dissipation factors at different frequencies. The results show that the fibers with non-polar surfaces (polyester) do not influence the hydration process of the cement matrix, whereas polypropylene fibres, with polar surfaces, have a definitive role on the curing properties of the composites.
Effect of Lay-Up on the Sorption Behaviour of Woven Glass-Polyester Composites
Authors: Elleuch R. , Chateauminois A. , Bradai Ch. , Derbel N.
Published: January 2019

The effects of the lay-up on the water diffusion behaviour of hand made woven glass/polyester composites have been investigated by means of sorption experiments and numerical simulation of the diffusion process in a stratified media. Experimental sorption curves exhibited a non linear behaviour during the initial sorption step. On the basis of the numerical simulations, this behaviour was attributed to an enhanced diffusion rate in the superficial matrix layers. These effects were found to affect significantly the measurement of the diffusion coefficient from the sorption curve.
DC and AC Conductivity in Polymeric Particulate Composites of Epoxy Resin and Metal Particles
Authors: Tsangaris G.M. , Psarras G.C. , Manolakaki E.
Published: January 2019

The DC and AC conductivity of composites with epoxy resin and nickel particles was investigated for various content of nickel powder from ambient to 120 °C. AC conductivity was measured in the frequency range 10 Hz to 13 MHz. An enhancement of conductivity was evidenced increasing conductive filler content and temperature. AC conductivity was found to be frequency dependent beyond a critical frequency ω c. The activation energy of the temperature shift of ω c was compared to the activation energy of DC conductivity.
Simulation of Resin Film Infusion Process using Finite Element/Nodal Control Volume Approach
Authors: Joshi Sunil C. , Liu Xiao-Lin , Lam Y.C. , Sheridan J.
Published: January 2019

A numerical scheme, which is interfaced with a general-purpose finite element package for the simulation of resin film infusion process, is presented. The movement of the resin within the film and the impregnation of the fabric preform are modelled simultaneously as a fixed boundary problem. Application of the scheme is demonstrated by simulating the fabrication of a generic L-section.
Effect of Pip Cycles on Fracture Behaviour in Unidirectional SiC Fibre-Reinforced SiC Matrix Composite
Authors: Kakisawa H. , Kagawa Y. , Takeda M. , Imai Y. , Ichikawa H.
Published: January 2019

The effect of pore volume fraction in unidirectional SiC fibre (Nicalon™)-reinforced SiC matrix composite fabricated by polymer infiltration pyrolysis (PIP) process on three-point bend fracture behaviour has been studied. The pore volume fraction, f u, is varied by changing the number of PIP cycles, N. Results shows that the shear fracture mode is dominant at f u ≥ 0.36 and the strength increased with the decrease of f u. On the other hand, the tensile mode was dominant at f u ≤ 0.17 and the tensile strength was independent of fu. Transition of the fracture mode occurred when the ratio of shear strength to constant tensile strength was reached ≈ 1/30.
Delayed diagnosis of long QT syndrome in a patient with seizures
Authors: Shin Seung Yong , Hong Jun Young , Lee Dong Hoon
Published: January 2019

Introduction:

Long QT syndrome accompanied by a seizure episode is often misdiagnosed as primary epilepsy. Although patients with Long QT syndrome who are misdiagnosed and improperly managed are likely to result in fatality, their first clinical manifestations are seizure episodes in many cases.

Case presentation:

A 17-year-old boy visited the emergency department with poorly controlled seizure during epilepsy treatment was found to have been misdiagnosed with epilepsy when he was 7 years old. His electrocardiography showed a prolonged QT interval. After careful re-evaluation, he was finally diagnosed with Long QT syndrome and recovered without any seizure episodes in the absence of anti-epileptic agents.

Discussion and conclusion:

Careful initial assessment including repetitive electrocardiography, when abnormal, is required for those who visit the emergency department with a seizure or who show no definite abnormalities in diagnostic work up process.
Structural instability of non-conservative functionally graded micro-beams tunable with piezoelectric layers
Authors: Hosseini Mohammad , Bahaadini Reza , Khalili-Parizi Zahra
Published: January 2019

This investigation aims to explore the non-conservative instability of a functionally graded material micro-beam subjected to a subtangential force. The functionally graded material micro-beam is integrated with piezoelectric layers on the lower and upper surfaces. To take size effect into account, the mathematical derivations are expanded in terms of three length scale parameters using the modified strain gradient theory in conjunction with the Euler–Bernoulli beam model. However, the modified strain gradient theory includes modified couple stress theory and classical theory as special cases. Applying extended Hamilton’s principle and Galerkin method, the governing equation and corresponding boundary conditions are obtained and then solved numerically by the eigenvalue analysis, respectively. The results illustrated effects of non-conservative parameter, length scale parameter, different material gradient index, and various values of piezoelectric voltage on the natural frequencies, flutter and divergence instabilities of a cantilever functionally graded material micro-beam. It is found that both the material gradient index and applied piezoelectric voltage have significant influence on the vibrational behaviors, divergence and flutter instability regions. Furthermore, a comparison between the various micro-beam theories on the basis of modified couple stress theory, modified strain gradient theory, and classical theory are presented.
The Integration of EMA and Single-Occasion Multimethod Assessment Data for a Complex Psychiatric Patient
Authors: Lewis Katie C. , Ridenour Jeremy M.
Published: January 2019

The utilization of multimethod assessment approaches can provide comprehensive information regarding daily interpersonal and personality functioning, increasing opportunities to guide treatment planning in a more personalized, evidence-based manner. The routine implementation of multimethod assessment within clinical settings, however, remains rare, and there are few studies that have reviewed the clinical utility of multimethod assessment. Our goal in this study was to analyze multimethod data collected from a single research subject enrolled in residential treatment in order to illustrate the process of integrating data across both single-occasion (e.g., self-report, performance-based, and behavioral tests) and multitimepoint (ecological momentary assessment of interpersonal experiences) dimensions. Results revealed both areas of convergence and divergence across measures, enabling the development of a complex clinical formulation that sharpened diagnostic considerations and contributed valuable insights to treatment planning. Our findings provide support for the value of incorporating multimethod assessment into routine clinical practice.
Empathy versus evidence: Does perspective-taking for a discrimination claimant bias judgments of institutional sexism?
Authors: Simon Stefanie , Magaldi Meagan E. , O’Brien Laurie T.
Published: January 2019

We examined whether perspective-taking increased people’s recognition of institutional sexism in cases where evidence was in favor or against a woman’s claim. In Experiment 1, participants who took the perspective of a woman claiming institutional sexism made greater attributions to discrimination than participants who remained objective, but only if legitimate evidence of discrimination was presented. Experiment 2 replicates and extends Experiment 1 with a nonstudent, jury-eligible sample. The present research suggests perspective-taking does not bias people’s perceptions and may be an effective strategy for increasing recognition of legitimate claims of institutional sexism.
‘Rigour’, ‘discipline’ and the ‘systematic’: The cultural construction of educational research identities?
Authors: Keiner Edwin
Published: January 2019

In the present scientific era which prefers evidence-based educational research and methodological gold standards, ‘rigour’, ‘discipline’ and the ‘systematic’ serve as standardising and homogenising concepts and as powerful identifiers of ‘normal science’ in the context of historical and cultural contingencies. These concepts serve to construct disciplinary identities and, furthermore, have the power to define what counts as rigour, discipline and the systematic – and what not. The article starts with the problems of terminology and shows that rigour, discipline and the systematic are rather vague and ambivalent concepts, especially when considering their meaning in different languages and cultures. The second part uses different foci of several theoretical approaches in order to show the meaning and functions of rigour, discipline and the systematic for constructing educational research identities and to explain different notions of these concepts in different research cultures. The final part considers the future and argues for the strengthening of a transversal, (meta-)reflexive and communicative dimension which both opens and limits the forms and formats of educational research employing diversity and intercultural communication as a valuable and powerful resource of sound scholarly research, mutual understanding and intellectual delight.
The Association Between Different Patterns of Traditional Chinese Medicine Treatment and All-Cause Mortality Among Cancer Patients
Authors: Lu Shao-Yi , Chen Jian-Jung , Pan Jiann-I , Fu Zi-Xuan , Wu Jung-Lun , Hsieh Tsung-Cheng
Published: January 2019

Background: Cancer patients receiving Western medical treatment, frequently seek Traditional Chinese Medicine (TCM) to alleviate adverse effects and prolong survival. Objective: This study evaluated the association between the use of TCM and cancer survival rate. Research into the effect of TCM on patient survival is limited, this analysis focused on 3 patterns of TCM use. Methods: Three retrospective cohorts with different patterns of TCM use were selected from the National Health Insurance Research Database of Taiwan and analyzed. Patients with newly diagnosed cancer between 1997 and 2012 were classified into groups of prediagnosis, postdiagnosis, and continuous TCM use associated with awareness of cancer diagnosis. All demographic and clinical data were analyzed. Results: After propensity score matching, longevity of the postdiagnosis and continuous TCM user was significantly longer than the non-TCM user. The adjusted hazard ratios of death in postdiagnosis and continuous TCM use groups (0.59 and 0.61, respectively) were lower than the non-TCM use group. Conclusion: The analysis suggests that cancer patients using TCM in conjunction with Western medical treatment exhibited a higher survival rate than patients not using TCM treatment.
Cross-Palm Nerve Grafts to Enhance Sensory Recovery in Severe Ulnar Neuropathy
Authors: Felder John M. , Hill Elspeth J. R. , Power Hollie A. , Hasak Jessica , Mackinnon Susan E.
Published: January 2019

Background: Intrinsic atrophy and debilitating sensory loss are prominent features of severe ulnar neuropathy with limited surgical options to reliably improve recovery. Restoration of sensation is important to provide protection for the vulnerable ulnar border of the hand. Here, we report our experience with side-to-side sensory nerve grafting from the median to ulnar nerve in the palm to enhance ulnar sensory recovery. Methods: A retrospective chart review identified patients with severe ulnar neuropathy who underwent cross-palm nerve grafting. Included patients had objective loss of protective sensation in the ulnar distribution with 2-point discrimination >8 mm, Semmes-Weinstein monofilament testing (SWMT) >4.56, or no sensory response on nerve conduction testing. Cross-palm side-to-side tension-free grafting from median to ulnar sensory components was performed using short-segment allograft or autografts. Analysis included patient etiology, procedures, nerve conduction studies, objective sensory testing, and Disabilities of the Arm, Shoulder, and Hand Disability score. Results: Forty-eight patients with severe ulnar neuropathy underwent cross-palm nerve grafting between 2014 and 2017. Twenty-four patients had adequate follow-up for inclusion. Of the 24 patients, 21 (87%) had return of protective sensation, 16 (66.7%) had return of diminished light touch sensation, and 6 (25%) had return to normal range sensation within 1 year as assessed by SWMT and/or 2-point discrimination. Patients treated with autograft demonstrated referred sensation to the median nerve distribution. Conclusions: Cross-palm nerve grafting may be a useful adjunct to enhance sensory recovery in severe ulnar neuropathy. Further study to quantify differences in sensory recovery between traditional operative techniques and cross-palm nerve grafting is required.
Characteristics and properties of nitrocellulose/glycidyl azide polymer/2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane nanocomposites synthesized using a sol–gel supercritical method
Authors: Wang Yi , Zhang Mi , Song Xiaolan , Huang Hao , Li Fengsheng
Published: January 2019

Nitrocellulose/glycidyl azide polymer/2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane nanocomposites, in which 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane nanoparticles uniformly embedded in nitrocellulose/glycidyl azide polymer matrix, were synthesized using a sol–gel supercritical method. The micron morphology, crystal phase, molecular structure, specific surface area, and surface elements were characterized using scanning electron microscopy, X-ray diffractometry, infrared, Brunauer–Emmett–Teller, and X-ray photoelectron spectroscopy analyses, respectively. Thermal analyses were performed, and the kinetic and thermodynamic parameters, such as activation energy, per-exponent factor, rate constant, activation heat, activation free energy, and activation entropy, were calculated. The decomposition products of the nitrocellulose/glycidyl azide polymer matrix and nitrocellulose/glycidyl azide polymer/2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane were also investigated by differential scanning calorimetry–infrared analysis. The result indicated that the main decomposition product of nitrocellulose/glycidyl azide polymer is carbon dioxide and the –N3 group in glycidyl azide polymer decomposed to nitrogen without being detected by infrared spectrometer; the main decomposition products of nitrocellulose/glycidyl azide polymer/2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane are carbon dioxide, nitrous oxide, and water, and few carbon monoxide, methane, and nitrogen oxide are also detected. Energy performances of nitrocellulose/glycidyl azide polymer matrix and nitrocellulose/glycidyl azide polymer/2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane nanocomposites were evaluated, that is, the parameters such as standard specific impulse, characteristic speed, combustion chamber temperature, average molecular weight of combustion products, and explosion heat were calculated. The results illustrated that as the weight percentage of nitrocellulose increases, the values of standard specific impulse, characteristic speed, average molecular weight of combustion products, combustion chamber temperature, and explosion heat increase. This was ascribed to that the oxygen balance of glycidyl azide polymer is substantially lower than that of nitrocellulose, which results in that the chemical energy of glycidyl azide polymer does not release sufficiently. Additionally, as weight percentage of glycidyl azide polymer increases, the impact and friction sensitivity of the composites decrease obviously. This means that glycidyl azide polymer is much more insensitive than nitrocellulose.
Insulin-Based Infusion System: Preliminary Study
Authors: Hashemi Nasseh , Valk Tim , Houlind Kim , Ejskjaer Niels
Published: January 2019

Background:

Optimal glucose control has been shown to be useful in critical care as well as in other settings. Glucose concentrations in patients admitted to critical care are characterized by marked variability and hypoglycemia due to inadequate sensing and treatment technologies.

Methods:

The insulin balanced infusion system (IBIS) is a closed-loop system that uses a system controller, two syringe pumps, and capillary glucose sensor intravenously infusing regular insulin and/or dextrose. The IBIS performance was evaluated in terms of glucose stability in response to various conditions in subjects with type 1 and insulin requiring type 2 diabetes mellitus (n = 15) with frequent intermittent capillary measurements, entered into the system and an adaptive algorithm adjusting the treatment modalities without other nursing intervention.

Results:

Target glucose concentrations (80-125 mg/dl) were achieved from hyperglycemic levels in 2.49 hours in the first study with mean and standard deviation of 105.2 mg/dl and 11.5 mg/dl, respectively.

Conclusion:

Preliminary studies using a prototype closed-loop glucose control system for critical care produced noticeable results. Improvements were initiated within the system and further studies performed.
Endothelial protein C receptor supports hematopoietic stem cell engraftment and expansion in Mpl-deficient mice
Authors: Kohlscheen Saskia , Schenk Franziska , Rommel Marcel G. E. , Cullmann Katharina , Modlich Ute
Published: January 2019

Thrombopoietin (Thpo)/myeloproliferative leukemia virus oncogene (Mpl) signaling controls hematopoietic stem cell (HSC) self-renewal and quiescence; however, how these 2 seemingly opposing functions are controlled is not well understood. By transplantation of lentiviral-transduced hematopoietic cells in the Mpl-deficient mouse model, we addressed whether known or predicted Thpo target genes were able to rescue the Mpl-deficient phenotype of the mice. Among the tested genes, we identified endothelial protein C receptor (Epcr) to expand HSCs with the long-term (LT)-HSC surface phenotype in Mpl−/− mice and to enable secondary transplantation of Mpl-deficient bone marrow (BM). Epcr-transduced Mpl−/− HSCs enter quiescence earlier after transplantation than control-transduced Mpl−/− cells, and upregulated expression of the anti-apoptotic gene Bcl-xL. Also, in the wild-type background, Epcr expression marked the engrafting population in the BM. Furthermore, Epcr expression in Mpl−/− hematopoiesis increased the number of megakaryocytes in the BM. In vitro Thpo supported the surface expression of Epcr on primary murine hematopoietic stem and progenitor cells. With these data, we add new insights into Thpo-dependent influence on HSC engraftment after transplantation. This may be of use for the in vitro manipulation of HSCs, also in the context of gene therapy.
Foot structure, pain and functional ability in people with gout in primary care: cross‐sectional findings from the Clinical Assessment Study of the Foot
Authors: Petty Helen R. , Rathod‐Mistry Trishna , Menz Hylton B. , Roddy Edward
Published: January 2019

Background

Gout frequently affects the foot yet relatively little is known about the effects of gout on foot structure, pain and functional ability. This study aimed to describe the impact of gout in a UK primary care population.

Methods

A cross‐sectional study was nested within an observational cohort study of adults aged ≥50 years with foot pain. Participants with gout were identified through their primary care medical records and each matched on age (±2 years) and gender to four participants without gout. Differences in person‐level variables (SF‐12 Physical Component Score, Manchester Foot Pain and Disability Index and Short Physical Performance Battery) between gout and non‐gout participants were determined using regression models. Differences in foot‐level variables (pain regions, skin lesions, deformities, foot posture, and non‐weightbearing range of motion) were determined using multi‐level regression models. All models were adjusted for body mass index. Means and probabilities with 95% confidence intervals were calculated.

Results

Twenty‐six participants with gout were compared to 102 participants without gout (77% male; mean age 66 years, standard deviation 11). Subtalar joint inversion and eversion and 1st metatarsophalangeal joint (MTPJ) dorsiflexion range of motion were significantly lower in the gout participants compared to the non‐gout participants. Gout participants were more likely to have mallet toes and less likely to have claw toes compared to non‐gout participants. There were no statistically significant differences in person‐level variables, foot posture, ankle dorsiflexion range of motion, hallux valgus, pain regions, or skin lesions.

Conclusions

Non‐weightbearing range of motion at the subtalar joint and 1st MTPJ was reduced in people with gout. Patients with gout who present with chronic foot problems should therefore undergo appropriate clinical assessment of foot structure.
A case study on receiver-clamping quality assessment from the seismic-interferometry processing of downhole seismic noise recordings
Authors: Yaskevich Sergey , A. Duchkov Anton , Myasnikov Artem
Published: January 2019

For downhole microseismic monitoring of hydraulic fracturing, the acquisition is performed using a set of three-component (3C) seismic receivers attached firmly to the borehole wall by a clamping mechanism. Such an acquisition cannot be repeated, and it is focused on recording weak signals. Thus, proper installation of the receivers is especially crucial for microseismic applications. We have developed a case study of using a seismic-interferometry approach for assessing the receiver’s installation quality from ambient-noise records. Crosscorrelation of one vertical receiver noise records with the others allows us to retrieve the direct body wave propagating along the receiver array. Our observations indicate that the inability to retrieve the direct body wave is an indicator of clamping issues. Our case study does not support the emergence-frequency hypothesis reported in the literature (that higher frequencies present in the retrieved body-wave spectrum imply better clamping quality). Another conclusion is that seismic-interferometry processing provides a stable assessment of the clamping quality only for the vertical receivers. Thus, one gets only partial diagnostics of the clamping quality for the 3C downhole tool. This is important because the horizontal components may be affected more by the clamping issues compared with the vertical components. The overall conclusion is that seismic-interferometry processing of noise records is recommended for the assessment of the downhole receiver installation prior to microseismic monitoring. It does not provide complete diagnostics but comes for free (does not need any additional technological operations or extra time).
On Trans* Epistemology
Authors: Radi Blas
Published: January 2019

This article explores the contents and differential traits of (a) trans* epistemology, as a way to contribute to a dialogue fundamental both from a scholarly perspective and from the point of view of trans* advocacy. The first section offers a brief introduction to trans* studies, highlighting some key aspects in relation to an epistemology rooted in philosophical reflection. The second section presents some of the main critiques trans* scholars have advanced in relation to the processes of knowledge production and its products. The section then moves on to some of the field's main constructive proposals in this respect. The third section builds on the concept of “cis” and “cissexism” to offer considerations on the nuanced relationship between critique and positive contributions, and on the resistance on the part of cis people to being named as such. Finally, the work offers some closing remarks in relation to the specificity and challenges of (a) trans* epistemology.
ApoE-associated modulation of neuroprotection from Aβ-mediated neurodegeneration in transgenic Caenorhabditis elegans
Authors: Griffin Edward F. , Scopel Samuel E. , Stephen Cayman A. , Holzhauer Adam C. , Vaji Madeline A. , Tuckey Ryan A. , Berkowitz Laura A. , Caldwell Kim A. , Caldwell Guy A.
Published: January 2019

Allele-specific distinctions in the human ApolipoproteinE (ApoE) locus represent the best characterized genetic predictor of Alzheimer's disease (AD) risk. Expression of isoform ApoEε2 is associated with reduced risk, while ApoEε3 is neutral and ApoEε4 carriers exhibit increased susceptibility. Using Caenorhabditis elegans, we generated a novel suite of humanized transgenic nematodes to facilitate neuronal modeling of amyloid-beta peptide (Aβ) co-expression in the context of distinct human ApoE alleles. We found that co-expression of human ApoEε2 with Aβ attenuated Aβ-induced neurodegeneration, while expression of the ApoEε4 allele had no effect on neurodegeneration, indicating a loss of neuroprotective capacity. Notably, the ApoEε3 allele displayed an intermediate phenotype; it was not neuroprotective in young adults but attenuated neurodegeneration in older animals. There was no functional impact from the three ApoE isoforms in the absence of Aβ co-expression. Pharmacological treatment that examined neuroprotective effects of ApoE alleles on calcium homeostasis showed allele-specific responses to changes in ER-associated calcium dynamics in the Aβ background. Additionally, Aβ suppressed survival, an effect that was rescued by ApoEε2 and ApoEε3, but not ApoEε4. Expression of the ApoE alleles in neurons, independent of Aβ, exerted no impact on survival. Taken together, these results illustrate that C. elegans provides a powerful in vivo platform with which to explore how AD-associated neuronal pathways are modulated by distinct ApoE gene products in the context of Aβ-associated neurotoxicity. The significance of both ApoE and Aβ to AD highlights the utility of this new pre-clinical model as a means to dissect their functional interrelationship.
Structure and function analysis of the C. elegans aminophospholipid translocase TAT–1
Authors: Chen Yu-Zen , Klöditz Katharina , Lee Eui-Seung , Nguyen Diemmy Pham , Yuan Quan , Johnson Jack , Lee-yow Yannick , Hall Adam , Mitani Shohei , Xia Ning-Shao , Fadeel Bengt , Xue Ding
Published: January 2019

The C. elegans aminophospholipid translocase TAT–1 maintains phosphatidylserine (PS) asymmetry in the plasma membrane and regulates endocytic transport. Despite these important functions, the structure-function relationship of this protein is poorly understood. Taking advantage of the tat-1 mutations identified by the C. elegans million mutation project, we investigated the effects of 16 single amino-acid substitutions on the two functions of the TAT–1 protein. Two substitutions that alter a highly conserved PISL motif in the fourth transmembrane domain and a highly conserved DKTGT phosphorylation motif, respectively, disrupt both functions of TAT-1, leading to a vesicular gut defect and ectopic PS exposure on cell surface, whereas most other substitutions across the TAT-1 protein, often predicted to be deleterious by bioinformatics programs, do not affect the functions of TAT-1. These results provide in vivo evidence for the importance of the PISL and DKTGT motifs in P4–type adenosine triphosphatases (ATPases) and improve our understanding of the structure-function relationship of TAT-1. Our study also provides an example of how the C. elegans million mutation project helps decipher the structure, functions, and mechanisms of action of important genes.
Rapid adjustment of pecking trajectory to prism-induced visual shifts in crows as compared to pigeons
Authors: Matsui Hiroshi , Izawa Ei-Ichi
Published: January 2019

Pecking in birds is analogous to reaching and grasping movements in primates. Earlier studies on visuomotor control in birds, which were conducted mostly in pigeons, suggested that avian pecking is controlled feedforwardly, and is out of the control of visual guidance during movement. However, recent studies using crows suggested a role of vision in pecking control during movement. To unveil what visuomotor mechanisms underlie the flexibility of pecking in crows, the current study examined whether pigeons and crows adjust their pecking to the visual distortion induced by prisms. Because prisms induce visual shifts of object positions, birds were required to adjust their movements. Pecking kinematics were examined before and after attaching prisms in front of the birds’ eyes. Analysis of lateral deviation caused by the prisms showed that crows rapidly adjusted their pecking trajectories, but pigeons did slowly. Angular displacement also increased in pigeons after attachment of the prism but decreased in crows. These responses to prisms were consistent among individuals in pigeons but varied in crows, though the adjustment of pecking commonly succeeded in crows. These results suggest that pecking in pigeons predominantly involves feedforward control and that the movement is determined depending on the visual information available before the initiation of pecking. In contrast, the results from crows suggest that their pecking trajectories are corrected during the movement, supporting on-line visual control. Our findings were the first evidence to suggest the on-line visual control of pecking in birds.
The development and evaluation of an online application to assist in the extraction of data from graphs for use in systematic reviews
Authors: Cramond Fala , O'Mara-Eves Alison , Doran-Constant Lee , Rice Andrew SC , Macleod Malcolm , Thomas James
Published: January 2019

Background:The extraction of data from the reports of primary studies, on which the results of systematic reviews depend, needs to be carried out accurately. To aid reliability, it is recommended that two researchers carry out data extraction independently. The extraction of statistical data from graphs in PDF files is particularly challenging, as the process is usually completely manual, and reviewers need sometimes to revert to holding a ruler against the page to read off values: an inherently time-consuming and error-prone process.

Methods:To mitigate some of the above problems we integrated and customised two existing JavaScript libraries to create a new web-based graphical data extraction tool to assist reviewers in extracting data from graphs. This tool aims to facilitate more accurate and timely data extraction through a user interface which can be used to extract data through mouse clicks. We carried out a non-inferiority evaluation to examine its performance in comparison to standard practice.

Results:We found that the customised graphical data extraction tool is not inferior to users’ prior preferred current approaches. Our study was not designed to show superiority, but suggests that there may be a saving in time of around 6 minutes per graph, accompanied by a substantial increase in accuracy.

Conclusions:Our study suggests that the incorporation of this type of tool in online systematic review software would be beneficial in facilitating the production of accurate and timely evidence synthesis to improve decision-making.
Periodic Little’s Law
Authors: Whitt Ward , Zhang Xiaopei
Published: January 2019

Motivated by our recent study of patient flow data from an Israeli emergency department (ED), we establish a sample path periodic Little’s law (PLL), which extends the sample path Little’s law (LL). The ED data analysis led us to propose a periodic stochastic process to represent the aggregate ED occupancy level, with the length of a periodic cycle being 1 week. Because we conducted the ED data analysis over successive hours, we construct our PLL in discrete time. The PLL helps explain the remarkable similarities between the simulation estimates of the average hourly ED occupancy level over a week using our proposed stochastic model fit to the data and direct estimates of the ED occupancy level from the data. We also establish a steady-state stochastic PLL, similar to the time-varying LL.

The e-companion is available at https://doi.org/10.1287/opre.2018.1766 .
Aprendizaje para todos: venciendo obstáculos en el estado de Amazonas
Authors: Costin Claudia Maria , Jales Coutinho Allan Michel
Published: January 2019

Brasil es signatario de varios tratados internacionales, entre ellos los Objetivos de Desarrollo Sostenible (ODS), que establecen, en su meta 4, que la educación debe de ser inclusiva, equitativa y de calidad, además de promover oportunidades de aprendizaje a lo largo de la vida para todos. Con un territorio de 1.571 millones de km2, el estado de Amazonas necesita superar obstáculos geográficos y estructurales para asegurar el acceso de miles de jóvenes a la escuela y así promover la igualdad de oportunidades a escala por medio de la educación básica. En este artículo, describimos el proceso de implantación del Centro de Medios del estado de Amazonas como una política pública innovadora que utiliza la tecnología interactiva como un inductor para la construcción de un sistema educativo equitativo. Argumentamos que la tecnología desempeña un papel de palanca de cambio junto con la formación inicial continuada de los profesores de las redes públicas.
El bioma amazónico y el Acuerdo de París: cooperación y gobernanza
Authors: De Las Casas César Augusto
Published: January 2019

Se plantea una nueva conceptualización en el modo de abordar la relación entre bioma amazónico y cambio climático, particularmente respecto a la implementación del Acuerdo de París sobre Cambio Climático y a la construcción de una buena gobernanza climática, para lo cual se propone la formulación de los sistemas social-ecológicos Tierra y Amazonia, respectivamente, como dos unidades distintas, pero conectadas para el análisis y la gestión de los problemas descritos, y cuya relación es fundamental para la construcción de la resiliencia. En ese contexto se destaca el papel de los pueblos indígenas de la Amazonia como protagonistas históricos de la adaptación y transformación del paisaje amazónico, dando prioridad a la necesidad de reconocer que las políticas públicas deben ser coherentes al integrar las políticas de mitigación y de adaptación en un sentido transformador.
Entrevista con Thomas Lovejoy
Authors: Val Adalberto Luis , Marcovitch Jacques
Published: January 2019

Thomas Lovejoy es un innovador y talentoso biólogo en el área de la conservación que, en 1980, acuñó el término de “diversidad biológica”. En 2010, fue elegido profesor en el departamento de Ciencia y política ambiental de la Universidad George Mason. Es miembro senior de la Fundación de las Naciones Unidas en Washington, D.C. Fue presidente del Heinz Center de 2002 a 2008 y catedrático en Biodiversidad. Antes de asumir la cátedra, Lovejoy fue consejero-jefe del Banco Mundial para la biodiversidad y principal especialista en medio ambiente para América Latina y Caribe. En la década de 1980, Thomas Lovejoy llamó la atención de la comunidad internacional sobre los bosques tropicales del mundo y, particularmete, sobre la Amazonia brasileña, donde trabaja desde 1965. Lovejoy también desarrolló los actuales omnipresentes programas de intercambio “deuda-por-naturaleza” y fue el líder del proyecto Tamaño Mínimo Crítico para los Ecosistemas. En 2001, Lovejoy recibió el prestigioso premio Tyler de Conquista Ambiental. En 2009, fue el ganador del premio BBVA Fronteras del Conocimiento en la categoría ecología y biología de la conservación. Ese mismo año, fue nombrado Conservation Fellow por la National Geographic. En 2012, recibió el premio Planeta Azul. Lovejoy es licenciado y doctor en Biología por la Universidad de Yale.
Conservación de la biota acuática de la Amazonia
Authors: Val Adalberto Luis
Published: January 2019

En las aguas amazónicas existen cerca de tres mil especies conocidas de peces, así como algunas otras especies acuáticas que incluyen algunos mamíferos, como el manatí. Es posible que muchas especies aún no hayan sido descritas por la ciencia. Los peces de esta región se enfrentan a condiciones naturales extremas en sus ambientes como bajos niveles de oxígeno, aguas ácidas y pobres en iones, altas temperaturas, sequías intensas e inundaciones. Los cambios climáticos globales están intensificando estas condiciones ambientales. Además, los cambios ambientales causados por el hombre, que trae consigo contaminantes orgánicos e inorgânicos, se están produciendo en muchas partes de la región. Estas condiciones ambientales representan desafíos para todas las especies de peces que exhiben ajustes en todos los niveles de la organización biológica. Conocer la capacidad adaptativa de estos animales permite diseñar estrategias de conservación de la biota acuática, así como proponer intervenciones ambientales más adecuadas. Por último, es fundamental considerar la importancia de la biota acuática para la plena implantación de los objetivos del desarrollo sostenible en la Amazonia.
Same- vs Different-Hospital Readmissions in Patients With Cirrhosis After Hospital Discharge
Authors: Okafor Philip N. , Nnadi Augustine K. , Okoli Okwuchukwu , Huang Alice E. , Nwaiwu Obioma
Published: January 2019

INTRODUCTION:

There is a lack of data on the impact of readmission to the same vs a different hospital following an index hospital discharge in cirrhosis patients.

METHODS:

We sought to describe rates and predictors of different-hospital readmissions (DHRs) among patients with cirrhosis and also determine the impact on cirrhosis outcomes including all-cause inpatient mortality and hospital costs. Using the national readmissions database, we identified cirrhosis hospitalizations in 2013. Regression analysis was used to determine the predictors of DHRs. A time-to-event analysis was performed to assess the impact on subsequent readmissions and all-cause inpatient mortality.

RESULTS:

In 2013, there were 109,039 cirrhosis readmissions with 67% of these being same-hospital readmissions and 33% being DHRs (P < 0.001). Two percent of readmitted patients were treated at ≥4 different hospitals. The 30-day readmission rate was 29.1%. Predictors of DHR included Medicaid payer (adjusted odds ratio [OR] 1.07, 95% confidence interval [95% CI] 1.01–1.14), age (OR 0.98, 95% CI 0.978–0.982), elective admission (OR 1.09, 95% CI 1.01–1.17), hepatic encephalopathy (OR 1.20, 95% CI 1.16–1.25), hepatorenal syndrome (OR 1.09, 95% CI 1.03–1.16), and low socioeconomic status (OR 1.15, 95% CI 1.06–1.25). No difference was observed in 30-day readmission risk following a DHR (adjusted hazard ratio 1.044, 95% CI 0.975–1.118). In addition, there was no increased risk of inpatient death observed during a DHR within 30 days (adjusted hazard ratio 1.08, 95% CI 0.94–1.23). However, patients with DHR had significantly higher hospital costs and length of stay.

CONCLUSIONS:

Majority of cirrhosis readmissions are same-hospital readmissions. Different-hospital readmissions do not increase the risk of 30-day readmissions and inpatient mortality but are associated with higher hospital costs.
Tecnologias para impressão e confecção de próteses sobre implante: revisão de literatura
Authors: Alves Kamila Aguiar Figueiredo , Damasceno Janaina Emanuela , Oliveira Viviane Maia Barreto , Bastos Luiz Gustavo Cavalcanti , Cavalcanti Andrea Nóbrega
Published: January 2019

A reabilitação com implantes tem sido considerada como primeira escolha para a substituição de dentes perdidos na Odontologia. Aliado a isso, estão em constante desenvolvimento materiais e tecnologias associados ao restabelecimento da estética, função, qualidade e longevidade para as restaurações protéticas. O objetivo do presente trabalho foi descrever o estado atual das tecnologias para impressão e confecção de próteses sobre implante, levando em consideração sua relevância, aplicação e indicação. De acordo com a literatura revisada, verifica-se que os diversos sistemas CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing) vêm sendo crescentemente utilizados na Implantodontia com propósito de automatizar um processo originalmente manual, visando reduzir o tempo de confecção das próteses e aumentar a confiabilidade nesse processo. Estudos demonstram que o desenvolvimento do sistema CAD/CAM resultou em melhora na reprodutibilidade, resistência mecânica e estética final das próteses implantossuportadas, aliadas à melhor aceitação pelo paciente. Por outro lado, ainda há limitações a serem superadas, como o alto custo, problemas com distorção dos modelos digitais e menor precisão em relação à impressão convencional, em algumas situações clínicas.
Técnica de Retentores Intrarradiculares: O ensino é devidamente valorizado? Uma avaliação radiográfica da qualidade de retentores
Authors: Barbosa Sthefane Brandão , Albuquerque Elisa Gomes , Passos Isabella de Almeida Guimarães , Marins Stella Soares , Warol Flávio , Scarparo Angela , Barceleiro Marcos de Oliveira
Published: January 2019

O objetivo do presente estudo foi avaliar a qualidade de retentores radiculares, através de radiografias periapicais de prontuários de 250 pacientes com pelo menos um elemento dental com retentor radicular. Foram analisados o tipo de retentor utilizado, a qualidade do tratamento endodôntico, o comprimento dos retentores e existência ou não de espaço entre o retentor e o material obturador endodôntico. De um total de 463 retentores, 324 eram núcleos metálicos fundidos, 118 eram pré-fabricados metálicos e 21 pré-fabricados não metálicos. 127 núcleos metálicos fundidos e 69 retentores pré-fabricados foram cimentados em dentes sem tratamento endodôntico ou com tratamento endodôntico insatisfatório. 35 núcleos metálicos fundidos, 12 pré-fabricados metálicos e 6 pré-fabricados não metálicos foram considerados satisfatórios. Observou-se grande número de falhas, que podem contribuir com fraturas ou outros tipos de falhas em dentes onde estes retentores radiculares estejam cimentados.