bluuebunny/crossref_metadata_2025 huggingface dataset:
Neuro-Ophthalmology at the Bedside: A Clinical Guide
Authors: Heckmann Josef G. , Vachalova Ivana , Lang Christoph J. G. , Pitz Susanne
Published: August 2018

Neuro-ophthalmological signs and symptoms are common in the emergency department but are a frequent source of diagnostic uncertainties. However, neuro-ophthalmological signs often allow a precise neuro-topographical localization of the clinical problem. A practical concept is presented how to perform a neuro-ophthalmological examination at the bedside and to interpret key findings under the aspect of emergency medicine with limited resources.
Acute Hemiplegia in Children: A Prospective Study of Etiology, Clinical Presentation, and Outcome from Western India
Authors: Chinnabhandar Vasant , Singh Amitabh , Mandal Anirban , Parmar B. J.
Published: August 2018

Background: Hemiplegia/hemiparesis denotes the weakness of one side of the body. In contrast to adults, hemiparesis in children occurs secondary to a variety of etiological conditions. Aims: The aim of this study was to assess the clinical, laboratory, and radiological features of children with acquired hemiparesis/hemiplegia of nontraumatic origin and intended to find its underlying etiology in the Indian children. Settings and Design: This prospective, observational study was carried out at a tertiary care hospital in western India. Materials and Methods: Children aged between 3 months and 14 years admitted to the in-patient department of a tertiary care hospital with acquired hemiparesis/hemiplegia were included over 2 years. Children with perinatal insult, preexisting neurological diseases, neurotrauma, hemiplegic migraine, and Todd's paralysis were excluded from the study. Detailed clinical examination, laboratory, and radiological investigations were done, and an attempt was made to find the underlying etiology. These children were also followed up after 1 month of discharge to look at short-term outcomes. All clinical information was recorded in a predesigned performa and was managed with Microsoft Excel spreadsheet. Frequency was presented as number (N) and percentage (%). Results: Fifty-five children (male:female = 1.2:1), predominantly between 1 and 5 years of age were studied. Apart from weakness (92.8%), vomiting (70.9%), fever (58.2%), and seizure (58.2%) were the predominant presenting complaints. One-fifth of them had comorbidities; most commonly congenital heart disease. Cerebral infarction was the most common pathology in neuroimaging. Central nervous system infection (45.5%) was the most common identified etiology followed by vascular events (21.8%). Among those who could be followed up at 1 month, about 65% had some improvement in their power. Conclusion: Infections continue to be an important cause of neurodisability in the developing countries.
Orbital Tuberculosis with Intracranial Extension
Authors: Diyora Batuk , Giri Sachin Ashok , Bhende Bhagyashri , Giri Deepali , Kukreja Sanjay , Sharma Alok
Published: August 2018

We report a case of orbital tuberculosis (OTB) with intracranial extension without active tuberculosis in the rest of the body organs or a history of tuberculosis infection. A 29-year-male patient presented with left-sided painful periorbital swelling with pus discharging sinus and visual impairment. Orbital computed tomography revealed contrast enhancing cystic mass lesion in the left orbit with erosion of the lateral and superior orbital wall with intracranial extension. After the failure of 3 weeks’ course of oral antibiotics, the patient underwent left lateral orbitotomy, pus was drained out, and granulation tissues were excised. Histopathological examination confirmed OTB. The patient had received antituberculous treatment. Periorbital swelling completely disappeared and vision improved over a period of 2 weeks. OTB should be considered in differential diagnosis of periorbital swelling especially when it does not respond to oral antibiotics.
Новые примеры транзитивных цилиндрических каскадов со свойством Безиковича
Authors: Kochergin Andrey Vasilyevich
Published: August 2018

Построены новые примеры транзитивных цилиндрических каскадов, имеющих дискретные орбиты (свойство Безиковича). Для любого $\gamma\in(0,1)$ существует цилиндрический каскад над некоторым поворотом окружности с $\gamma$-гeльдеровой функцией, который обладает свойством Безиковича, причем размерность Хаусдорфа множества точек окружности, имеющих дискретные орбиты, не меньше $1-\gamma$. Эта оценка лучше (на $\varepsilon$) полученной ранее. Кроме того, построен пример каскада, обладающего дискретными орбитами, с функцией, удовлетворяющей условию Гeльдера с любым показателем $\gamma\in(0,1)$.
Библиография: 16 названий.
Устойчивость по Уламу-Хайерсу-Миттаг-Леффлеру для нелинейных дифференциальных уравнений дробного порядка нейтрального типа
Authors: Niazi Azmat Ullah Khan , Wei Jiang , Rehman Mujeeb Ur , Denghao Pang
Published: August 2018

Обсуждаются два результата (в терминах чебышeвской нормы и нормы Билецкого) относительно существования и единственности для одного класса нелинейных функционально дифференциальных уравнений дробного порядка с запаздыванием, содержащих производные Капуто дробного порядка. С помощью операторов Пикара доказываются утверждения, касающиеся устойчивости по Уламу-Хайерсу-Миттаг-Леффлеру на отрезке. Приводятся два примера, иллюстрирующие полученные результаты.
Библиография: 29 названий.
Асимптотика собственных колебаний длинной двумерной пластины Кирхгофа с переменным сечением
Authors: Nazarov Sergei Aleksandrovich
Published: August 2018

После масштабирования длинная пластина Кирхгофа с жестко защемленными торцами и свободными боковыми сторонами описывается смешанной краевой задачей для бигармонического оператора в тонкой области со слабо искривленной границей. На основе общей процедуры построения асимптотики решений эллиптических задач в тонких областях выведены и обоснованы асимптотические разложения собственных чисел и функций поставленной задачи по малому параметру - относительной ширине пластины. В низкочастотном диапазоне спектра в качестве предельной выступает задача Дирихле для обыкновенного дифференциального уравнения четвертого порядка с переменными коэффициентами, а в среднечастотном (вполне неожиданно) - задача Дирихле для уравнения второго порядка. Изучено явление пограничного слоя около торцов пластины, позволяющее построить бесконечные формальные асимптотические ряды для простых собственных чисел и соответствующих собственных функций, а также создать модель повышенной точности. Обсуждаются асимптотические конструкции в случае пластин с периодическими быстроосциллирующими границами или с иными группами краевых условий, отвечающих механически осмысленным способам крепления краев пластины.
Библиография: 46 названий.
GENOTYPING OF BALAMUTHIA MANDRILLARIS BASED ON NUCLEAR 18S AND MITOCHONDRIAL 16S rRNA GENES
Authors: BOOTON GREGORY C. , CARMICHAEL JENNIFER R. , VISVESVARA GOVINDA S. , BYERS THOMAS J. , FUERST PAUL A.
Published: August 2018

Balamuthia mandrillaris is an opportunistically pathogenic ameba that causes fatal granulomatous amebic encephalitis (GAE) in vertebrates. Previous phylogenetic analyses that included the sequence of a single nuclear small subunit ribosomal RNA gene (18S or ssu rDNA) from this ameba suggested that Balamuthia is closely related to Acanthamoeba, another opportunistically pathogenic amebic genus, which includes multiple ssu rDNA genotypes. We tested whether this also is true for Balamuthia. The nuclear ssu rDNA from 4 isolates and the mitochondrial ssu rDNA from 7 isolates of B. mandrillaris have been sequenced. No variation in the nuclear rDNA sequences and low levels of variation in the mitochondrial rDNA were found. Both gene sequences were consistent with a single genotype for B. mandrillaris. The mitochondrial sequences of B. mandrillaris are unique and should be useful for development of genus-specific diagnostic probes for use with clinical, environmental, and archived specimens.
Integrated Steering Systems to Enhance Manoeuvrability: Technical Note
Authors: Palanivendhan M. , Banwar U. , Vyas S. , Bohra S.
Published: August 2018

Most vehicles today employ conventional steering system where the front wheels are solely responsible for steering the vehicle, due to this the rear wheels remain dependent of the front wheels in the dynamic condition which is not allowing the vehicle to reach its maximum potential. On the other hand, in a four-wheel steering system the rear wheels along with the front wheels steer the vehicle improving its manoeuvrability. Four wheels steering also produces better acceleration as power is distributed to all the four-wheels enhancing the net traction and reducing the overall rolling resistance. Vehicles today are designed to under-steer a little with a steering ratio ranging between 14 and 22, this phenomenon fails in few scenarios where it takes longer to manoeuvre a vehicle in case of lane emergencies. Implementing in-phase and counter-phase steering mechanisms in a vehicle allow sharper turn, reduces tire wear and improves the overall manoeuvrability of the vehicle. Factors like steering torque, turning angle and velocity of the vehicle are taken into consideration for devising a proper method to shift between different steering modes. The input from steering angle and torque at a certain speed, allows the vehicle to choose between the crabs, parallel or counter steering mechanism during a turn for best performance. Thereby, integrating these mechanisms in a single vehicle would invariably stabilize and provide a better control to the driver in high as well as slow speed conditions.
Reinforcing VANET Security using Ant Colony Optimization through Heuristic Approach
Authors: Gopikrishnan S. , Krishnaraj C. , Kokilavani K.
Published: August 2018

Vehicular ad hoc network (VANET) is a novice technique which has drawn the attention of several industries and academics. Security parameters in VANET are now receiving popularity in the research community. A defensive mechanism provides a solution to control the attacks across the VANET security. However, a single defence mechanism is unable to provide solution to the attack models as more sophisticated method is required for VANETs. This paper proposed a method termed heuristic approach for ant colony optimization (HAAC) for improved security in addition to better transportation, reliability and management. The heuristic based ant colony optimization is used to reduce the problem in finding known and unknown opponents in providing security to VANET. The characteristic of real ant colonies is used in VANET security in order to solve attack problems with shortest path. The Reinforcing VANET security using vehicle mode analysis is evaluated in an efficient manner using NS2 simulator. The excellent outcomes are obtained by an HAAC approach combined with a dynamic heuristic.
Development and Testing of Nano-Clay Composites for Pressure Pad Application
Authors: Vijaykumar M.S. , Saravanan R. , Rajasekar K. , Dhandapani N.V.
Published: August 2018

Pressure pads are used in mobile cranes and launch vehicles to distribute the reaction forces uniformly on the soil. In mobile cranes these pressure pads made on alloy steel and permanently fixed below the elephant foot through ball and socket joint. Launch vehicles are used to carry and outrigger the missiles in operating field or war field. Load distribution during the outrigger will be challenging in uneven ground surfaces and loose soils. Pressure pads add the flexibility in outriggering the missiles even in a loose soil with ground pressure of 4kg/cm2. Considering the place of application, detachable type pressure pads are used in launch vehicles. Aluminium alloy is preferred over the steel due to its less weight and easy handling. In this research study nano-clay epoxy composites are proposed as an alternate material for pressure pads of launch vehicles due to its high compression load and strength to weight ratio. The present study focused on the preparation of nano-clay epoxy composites and neat epoxy composites. The work further analyzed the deflection of composites during forward and reverse loading. Creep test was also conducted for a period of 4 hours. The test results revealed that the nano-clay composites were bearing more compressive strength with lesser weight than neat resin composites.
Optimization of Machining Parameters on Electrochemical Micro Machining of Hastelloy C22 using Grey Taguchi Method
Authors: Manoj Samson R. , Arun Raj A.C. , Geethapriyan T. , Senkathir S. , Jenoris Muthiya S.
Published: August 2018

Electro Chemical Machining (ECM) is a process that is used to machine extremely hard materials easily. It is a non-contact machining process. This ensures a higher tool life and no friction generated. The entire process is based on faradays laws of electrochemical process. With no heat affected zones (HAZ), this process holds a significant advantage over other high precision processes. This ensures that the material has neither thermal nor any other residual stresses. Nickel based alloys are known for their hardness and non-corrosive properties. This makes them unviable for machining using conventional methods as the overhead costs rise and makes them unproductive for use. ECM provides a better alternative comparatively. The alloy chosen for this analysis is Hastelloy C22. Its higher chromium content gives it better corrosion and pitting resistance. The objective of this analysis is to find the effects of various process parameters on MRR, surface finish, and dimensional deviation. The Taguchi technique has been used to investigate the effects of the ECMM process parameters and subsequently to predict sets of optimal parameters for maximum MRR and better surface finish. Grey analysis is done to find the optimal set of parameters for machining.
Sliding Mode Controller with Nonlinear Sliding Surface for Two-Link Planar Manipulator
Authors: Kow Yu-Yang , Ho Jee-Hou , Chai Tong-Yuen
Published: August 2018

The objective of this paper is to propose a method to control a two-link planar manipulator using a sliding mode controller with higher order sliding surface. Earlier approaches of varying sliding surface are time dependent and this may not yield optimal performance as the rotating surface does not depend on the dynamic states of the system. In this paper, the proposed control law alters the sliding surface based on the error states to drive the trajectory approaching the sliding phase quicker. A new sliding manifold is established and tuned until error decreases to zero. Stability is ensured through Lyapunov theorem and the trajectory is driven towards a designed sliding surface. The performance of the proposed controller is evaluated and compared against the conventional sliding mode controller as well as the previous approach of rotating sliding surface controller. Results showed that the proposed controller improved the respond speed and shortened the reaching phase. Although the chattering phenomenon remains, it enhanced the flexibility to adapt to the variation of system settings (e.g. torque limit).
Experimental Investigation of Ignition Timing on the Performance and Emission Characteristics of a Crank-Rocker Engine
Authors: Mohammed Salah E. , Baharom M.B. , Aziz A. Rashid A. , Zainal A. Ezrann Z. , Firmansyah F.
Published: August 2018

The effects of varying the ignition timing on the performance and emissions characteristics of a crank-rocker engine were experimentally investigated. Experiments were carried out at five different ignition timings of 6.5Â°, 8.5Â°, 10.5Â°, 12.5Â°and 14.5Â° CA BTDC at engine speed of 2000rpm and wide open throttle position. Performance data such as brake torque, brake power, brake specific fuel consumption and brake thermal efficiency were calculated. Engine exhaust gas emission such as CO, CO2, HC and NOx have also been measured. The results showed that at 10.5Â° CA (BTDC) ignition timing, the crank-rocker engine produce maximum brake torque, brake power, BTE and minimum value for the BSFC. In general, CO and HC emissions decreased while CO2 and NOx emissions increased with ignition timing advance. The findings in this paper are useful for researchers and engine developers in understanding the trade-offs and physical limitations of crank-rocker engine designs
Electrochemical Behavior of Alloy 825 at High-Temperature Pressurized Water–Chloride Solutions (30°C to 280°C)
Authors: Zhang Lefu , Wang Jiamei , Arjmand Farzin
Published: August 2018

Variations in the transpassive potential (Et) and open circuit potential (OCP) of Alloy 825 were investigated at high-temperature pressurized water–Cl solutions. Using an experimental design strategy, the effects of temperature (T) (30°C to 280°C), Cl− concentration (10 ppb to 1,000 ppb), and dissolved oxygen (DO) concentration (0 ppb to 200 ppb) on the electrochemical responses (Et and OCP) of the alloy were analyzed by conducting only a short series of experiments. The optimum values of each factor was obtained from the designed matrix of the experiments and the constructed 3D response surface plots based on the most positive values of the Et and OCP. The optimum experimental conditions in which the most positive Et can be recorded was found as follows: T ≈ 30°C (significant), [Cl−] ≈ 10 ppb (significant), and [DO] ≈ 200 ppb (less significant). The most positive OCP values were recorded when the analyzed factors were as follows: T ≈ 120°C (significant), [DO] ≈ 200 ppb, and [Cl−] ≈ 10 ppb (less significant). Finally, the microscopic surface analysis of the alloy coupons revealed the great impact of temperature on the oxide film formation on Alloy 825.
Aerosol distribution in the northern Gulf of Guinea: local anthropogenic sources, long-range transport, and the role of coastal shallow circulations
Authors: Flamant Cyrille , Deroubaix Adrien , Chazette Patrick , Brito Joel , Gaetani Marco , Knippertz Peter , Fink Andreas H. , de Coetlogon Gaëlle , Menut Laurent , Colomb Aurélie , Denjean Cyrielle , Meynadier Rémi , Rosenberg Philip , Dupuy Regis , Dominutti Pamela , Duplissy Jonathan , Bourrianne Thierry , Schwarzenboeck Alfons , Ramonet Michel , Totems Julien
Published: August 2018

Abstract. The complex vertical distribution of aerosols over coastal southern West Africa (SWA) is investigated using airborne observations and numerical simulations. Observations were gathered on 2 July 2016 offshore of Ghana and Togo, during the field phase of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa project. This was the only flight conducted over the ocean during which a downward-looking lidar was operational. The aerosol loading in the lower troposphere includes emissions from coastal cities (Accra, Lomé, Cotonou, and Lagos) as well as biomass burning aerosol and dust associated with long-range transport from central Africa and the Sahara, respectively. Our results indicate that the aerosol distribution on this day is impacted by subsidence associated with zonal and meridional regional-scale overturning circulations associated with the land–sea surface temperature contrast and orography over Ghana and Togo, as typically observed on hot, cloud-free summer days such as 2 July 2016. Furthermore, we show that the zonal circulation evidenced on 2 July is a persistent feature over the Gulf of Guinea during July 2016. Numerical tracer release experiments highlight the dominance of aged emissions from Accra on the observed pollution plume loadings over the ocean, in the area of aircraft operation. The contribution of aged emission from Lomé and Cotonou is also evident above the marine boundary layer. Given the general direction of the monsoon flow, the tracer experiments indicate no contribution from Lagos emissions to the atmospheric composition of the area west of Cotonou, where our airborne observations were gathered. The tracer plume does not extend very far south over the ocean (i.e. less than 100 km from Accra), mostly because emissions are transported northeastward near the surface over land and westward above the marine atmospheric boundary layer. The latter is possible due to interactions between the monsoon flow, complex terrain, and land–sea breeze systems, which support the vertical mixing of the urban pollution. This work sheds light on the complex – and to date undocumented – mechanisms by which coastal shallow circulations can distribute atmospheric pollutants over the densely populated SWA region.
Solar 27-day signatures in standard phase height
measurements above central Europe
Authors: von Savigny Christian , Peters Dieter H. W. , Entzian Günter
Published: August 2018

Abstract. We report on the effect of solar variability at the 27-day and the 11-year time scale on standard phase height measurements carried out in central Europe. Using the superposed epoch analysis (SEA) method, we extract statistically highly significant solar 27-day signatures in standard phase heights. The 27-day signatures are roughly anti-correlated to solar proxies, such as the F10.7 cm radio flux or the Lyman-α flux. The sensitivity of standard phase height change to solar forcing at the 27-day time scale is found to be in good agreement with the sensitivity for the 11-year solar cycle, suggesting similar underlying mechanisms. The amplitude of the 27-day signature in standard phase height is larger during solar minimum than during solar maximum, indicating that the signature is not only driven by photo-ionisation of NO. We identified statistical evidence for an influence of ultra-long planetary waves on the quasi 27-day signature of standard phase height in winters of solar minimum periods.
Conversion of tropical forests to smallholder rubber and oil palm plantations impacts nutrient leaching losses and nutrient retention efficiency in highly weathered soils
Authors: Kurniawan Syahrul , Corre Marife D. , Matson Amanda L. , Schulte-Bisping Hubert , Utami Sri Rahayu , van Straaten Oliver , Veldkamp Edzo
Published: August 2018

Abstract. Conversion of forest to rubber
and oil palm plantations is widespread in Sumatra, Indonesia, and it is
largely unknown how such land-use conversion affects nutrient leaching
losses. Our study aimed to quantify nutrient leaching and nutrient retention
efficiency in the soil after land-use conversion to smallholder rubber and
oil palm plantations. In Jambi province, Indonesia, we selected two
landscapes on highly weathered Acrisol soils that mainly differed in texture:
loam and clay. Within each soil type, we compared two reference land uses,
lowland forest and jungle rubber (defined as rubber trees interspersed in
secondary forest), with two converted land uses: smallholder rubber and oil
palm plantations. Within each soil type, the first three land uses were
represented by 4 replicate sites and the oil palm by three sites, totaling
30 sites. We measured leaching losses using suction cup lysimeters
sampled biweekly to monthly from February to December 2013. Forests and
jungle rubber had low solute concentrations in drainage water, suggesting low
internal inputs of rock-derived nutrients and efficient internal cycling of
nutrients. These reference land uses on the clay Acrisol soils had lower
leaching of dissolved N and base cations (P= 0.01–0.06) and higher N and
base cation retention efficiency (P < 0.01–0.07) than those on
the loam Acrisols. In the converted land uses, particularly on the loam
Acrisol, the fertilized area of oil palm plantations showed higher leaching
of dissolved N, organic C, and base cations (P < 0.01–0.08) and
lower N and base cation retention efficiency compared to all the other land
uses (P < 0.01–0.06). The unfertilized rubber plantations,
particularly on the loam Acrisol, showed lower leaching of dissolved P (P=0.08) and organic C (P < 0.01) compared to forest or jungle
rubber, reflecting decreases in soil P stocks and C inputs to the soil. Our
results suggest that land-use conversion to rubber and oil palm causes
disruption of initially efficient nutrient cycling, which decreases nutrient
availability. Over time, smallholders will likely be increasingly reliant on
fertilization, with the risk of diminishing water quality due to increased
nutrient leaching. Thus, there is a need to develop management practices to
minimize leaching while sustaining productivity.
Modelling land atmosphere daily exchanges of NO, NH3, and CO2 in
a semi-arid grazed ecosystem in Senegal
Authors: Delon Claire , Galy-Lacaux Corinne , Serça Dominique , Personne Erwan , Mougin Eric , Adon Marcellin , Le Dantec Valérie , Loubet Benjamin , Fensholt Rasmus , Tagesson Torbern
Published: August 2018

Abstract. Three different models (STEP-GENDEC-NOflux, Zhang2010 and Surfatm) are used to simulate NO, CO2, and NH3 fluxes at the daily scale during two years (2012–2013) in a semi-arid grazed ecosystem at Dahra (15°24′10′′ N, 15°25′56′′ W, Senegal, Sahel). Model results are evaluated against experimental results acquired during three field campaigns. At the end of the dry season, when the first rains rewet the dry soils, the model STEP-GENDEC-NOflux simulate the sudden mineralization of buried litter, leading to pulses in soil respiration and NO fluxes. The contribution of wet season fluxes of NO and CO2 to the annual mean is respectively 51 % and 57 %. NH3 fluxes are simulated by two models: Surfatm and Zhang2010. During the wet season, air humidity and soil moisture increase, leading to a transition between low soil NH3 emissions (which dominate during the dry months) to large NH3 deposition on vegetation during wet months, Results show a great impact of the soil emission potential and a close agreement between the two models. The order of magnitude of NO, NH3 and CO2 fluxes are correctly represented by the models, as well as the sharp transitions between seasons, specific to the Sahel region. The role of soil moisture on flux magnitude is highlighted, whereas the role of soil temperature is less obvious. The simultaneous increase of NO and CO2 emissions and NH3 deposition at the beginning of the wet season is attributed to the availability of mineral nitrogen in the soil and also to microbial processes which distribute the roles between respiration (CO2 emissions), nitrification (NO emissions), volatilization and deposition (NH3 emission/deposition). This objective of this study is to understand the origin of carbon and nitrogen compounds exchanges between the soil and the atmosphere, and to quantify these exchanges on a longer time scale when only few measurements have been performed.
Causal dependences between the coupled ocean–atmosphere dynamics over the tropical Pacific, the North Pacific and the North Atlantic
Authors: Vannitsem Stéphane , Ekelmans Pierre
Published: August 2018

Abstract. The causal dependences (in a dynamical sense) between the dynamics of three
different coupled ocean–atmosphere basins, the North Atlantic, the North
Pacific and the tropical Pacific region (Nino3.4), have been explored using
data from three reanalysis datasets, namely ORA-20C, ORAS4 and ERA-20C. The
approach is based on convergent cross mapping (CCM) developed by
Sugihara et al. (2012) that allows for evaluating the dependences between
variables beyond the classical teleconnection patterns based on correlations. The use of CCM on these data mostly reveals that (i) the tropical Pacific
(Nino3.4 region) only influences the dynamics of the North Atlantic region
through its annual climatological cycle; (ii) the atmosphere over the North
Pacific is dynamically forcing the North Atlantic on a monthly basis; (iii)
on longer timescales (interannual), the dynamics of the North Pacific and
the North Atlantic are influencing each other through the ocean dynamics,
suggesting a connection through the thermohaline circulation. These findings shed a new light on the coupling between these three different regions of the globe. In
particular, they call for a deep reassessment of the way teleconnections are
interpreted and for a more rigorous way to evaluate dynamical dependences
between the different components of the climate system.
Uniaxial compression of calcite single crystals at room temperature: insights into twinning activation and development
Authors: Parlangeau Camille , Dimanov Alexandre , Lacombe Olivier , Hallais Simon , Daniel Jean-Marc
Published: August 2018

Abstract. E-twinning is a common plastic deformation mechanism in calcite deformed at low temperature. Strain rate, temperature and confining pressure have negligible effects on twinning activation that is mainly dependent on differential stress. The critical resolved shear stress (CRSS) required for twinning activation is dependent on grain size and strain hardening. This CRSS value may obey the Hall-Petch relation, but due to sparse experimental data its actual evolution with grain size and strain still remains a matter of debate. In order to provide additional constraints on twinning activation and development, new mechanical tests were carried out at room temperature on unconfined single crystals of calcite, with different sizes and crystallographic orientations. Uniaxial deformation was performed at controlled displacement rate, meanwhile the sample surface was monitored using optical microscopy and high resolution CCD camera. The retrieved macroscopic stress-strain behavior of the crystals was correlated with the surface observations of the deformation process. Results show (1) the onset of crystal plasticity with the activation of the first isolated mechanical twins during the strain hardening stage, and (2) the densification and thickening of twin lamellae during the steady state flow stress stage. Such thickening of twin lamellae at room temperature emphasizes that calcite twin morphology is not only controlled by temperature. The different values for the CRSS obtained for the activation of isolated twins and for the onset of twin densification and thickening questions the appropriate value to be considered when using calcite twin data for stress inversion purposes.
Modelled subglacial floods and tunnel valleys control the life cycle of transitory ice streams
Authors: Lelandais Thomas , Ravier Édouard , Pochat Stéphane , Bourgeois Olivier , Clark Christopher , Mourgues Régis , Strzerzynski Pierre
Published: August 2018

Abstract. Ice streams are corridors of fast-flowing ice that control mass transfers
from continental ice sheets to oceans. Their flow speeds are known to
accelerate and decelerate, their activity can switch on and off, and even
their locations can shift entirely. Our analogue physical experiments reveal
that a life cycle incorporating evolving subglacial meltwater routing and bed
erosion can govern this complex transitory behaviour. The modelled ice
streams switch on and accelerate when subglacial water pockets drain as
marginal outburst floods (basal decoupling). Then they decelerate when the
lubricating water drainage system spontaneously organizes itself into
channels that create tunnel valleys (partial basal recoupling). The ice
streams surge or jump in location when these water drainage systems maintain
low discharge but they ultimately switch off when tunnel valleys have
expanded to develop efficient drainage systems. Beyond reconciling
previously disconnected observations of modern and ancient ice streams into
a single life cycle, the modelling suggests that tunnel valley development
may be crucial in stabilizing portions of ice sheets during periods of
climate change.
Líquenes cortícolas de las áreas urbanas y suburbanas de Morelia, Michoacán, México
Authors: Gregorio-Cipriano María del Rosario , Gómez-Peralta Marlene , Álvarez Isela
Published: August 2018

En este trabajo se presenta la diversidad de líquenes que se desarrollan sobre árboles nativos e introducidos en las avenidas y áreas verdes, urbanas y suburbanas de Morelia. Se enlistan 49 especies distribuidas en 26 géneros y 10 familias, de las cuales, 39 se registran por primera vez para Morelia e incluyen 27 nuevas citas para el estado de Michoacán y una para México (Hyperphyscia isidiata). Las familias Physciaceae y Parmeliaceae fueron las mejor representadas con el 71% de las especies registradas. El 69,39% presentan talo foliáceo y el 30,61% talo crustáceo; mientras que los líquenes fruticulosos estuvieron ausentes en el área.
Anotaciones a la flora vascular del Parque Nacional de Monfragüe y su área de influencia (Cáceres, España)
Authors: Belmonte López Mª Dolores
Published: August 2018

Se revisan los catálogos y listados de flora vascular del Parque Nacional de Monfragüe y área de influencia conocidos hasta la fecha (1987-2008) en base a la taxonomía y corología de Flora iberica. Se proponen nuevos taxones y testimonios recientes de taxones citados por Rivas Mateos (1897-1931). Se incorporan citas bibliográficas (1969-2008) para el territorio y las publicadas en fecha posterior (2009-2015). Se indican aquellos taxones cuya presencia en el territorio debe ser evaluada de nuevo.
Aportaciones a la flora alóctona de Córdoba y Andalucía Occidental (España)
Authors: Muñoz-Álvarez Jesús M. , Delgado-Marzo Juan M. , Díaz-Iglesias María L.
Published: August 2018

Se citan por primera vez para la provincia de Córdoba cuatro taxones alóctonos: Amaranthus blitum subsp. emarginatus, Chamaesyce maculata, Onobrychis viciifolia y Proboscidea louisianica, todos ellos poco frecuentes en Andalucía occidental (y en Andalucía en general). Para cada uno de ellos se ha identificado el origen: predominan los procedentes de América del Norte; estatus de invasión (para A. occidental): naturalizado, invasor, casual y casual, respectivamente; estatus de residencia: los cuatro son neófitos; hábitat: predominan los de zonas construidas y tierras cultivadas; vía de introducción: involuntaria excepto en el caso de O. viciifolia, que se ha considerado intencionada; y primera cita conocida (para A. occidental), entre 1886 (O. viciifolia) y 2001 (P. louisianica). Se ha analizado además la dificultad de identificar el estatus de invasión.
Criptógamas atribuidos a Antonio José Cavanilles (1745-1804), y su entorno, conservadas en el herbario del Real Colegio ‘Alfonso XII’ (San Lorenzo de El Escorial, Madrid)
Authors: González-Bueno Antonio , Carrasco María Andrea , Perea Domingo
Published: August 2018

Damos cuenta de una colección histórica de 129 criptógamas; todas ellas, salvo cuatro pliegos atribuibles a Mariano La Gasca (1776-1839) y uno de Luis Neé (1734-1803), fueron identificadas por Antonio José Cavanilles (1745-1804). Estos materiales se conservan entre los fondos del Herbario del Real Colegio Alfonso XII de San Lorenzo de El Escorial (Madrid); salvo un pliegos de Luis Neé, fechado en 1786, los demás carecen de indicaciones sobre la localidad y fecha de herborización, pero por el carácter manuscrito de las etiquetas y por el interés que este grupo de plantas despertó en A.J. Cavanilles durante los primeros años del siglo XIX, permiten datar los ejemplares entre 1786 y 1804.
El bilingüismo como protección ante la demencia: Inconsistencias empíricas y nuevas propuestas metodológicas
Authors: Calvo Noelia , Manoiloff Laura , Muñoz Edinson , Contreras Marcela , Ibáñez Agustín , M. García Adolfo
Published: August 2018

El deterioro cognitivo durante el envejecimiento normal o patológico puede retrasarse mediante experiencias que fomentan la reserva cognitiva. En este sentido, algunos estudios indican que el bilingüismo retrasaría los síntomas de la enfermedad de Alzheimer. Sin embargo, la evidencia se basa en diseños retrospectivos que arrojan resultados contradictorios. Este trabajo analiza dichos resultados, identifica las principales variables detrás de sus discrepancias y propone alternativas metodológicas. Primero, caracterizamos los posibles factores de confusión, a saber: criterios para definir el bilingüismo, diferencias en los diseños muestrales, instrumentos empleados para estudiar las habilidades cognitivas y variables que modulan el desempeño cognitivo. Luego proponemos que estas limitaciones se podrían evitar mediante diseños experimentales y el uso de instrumentos adecuados para controlar eficazmente dichas variables. Además, sugerimos incorporar tareas que ya han demostrado patrones predecibles de desempeño contrastivo entre individuos bilingües y monolingües (desventajas bilingües en el vocabulario, efectos nulos en ciertos componentes de la memoria de trabajo y ventajas en el control inhibitorio), y otras que podrían sumar datos muy valiosos (como las tareas de interferencia proactiva). Estas consideraciones pueden arrojar luz no sólo sobre la relación entre bilingüismo y reserva cognitiva, sino también sobre mecanismos más generales de compensación cognitiva.
Humanizing brands through story-telling in magazine advertising
Authors: Martín de la Rosa Victoria , Domínguez Romero Elena
Published: August 2018

Within the framework of Conceptual Metaphor Theory, where metaphor allows human beings to map structure from concrete realms of experience (based on sensory-motor experience) to other more abstract domains, the Source-Path-Goal schema stands as one of the central concepts in human conceptualization. Its importance lies in the way it unifies and gives structure to concepts of motion. In turn, this embodied notion shapes our understanding of a purposeful activity, in which some path is traversed in order to reach for a goal, and our understanding of story-telling where, based on the same notion of a path, there is a development of characters in quest of a goal. On this basis, our purpose in this paper is to analyze three magazine advertisements in an attempt to reveal Conceptual Metaphor Theory, embodied cognition, image schemas, magazine advertising
Pregones y bandos: tradición escrita y transmisión oral en textos de autoridad
Authors: Pérez-Salazar Carmela
Published: August 2018

La transmisión de noticias en voz alta se prolonga desde la Edad Media hasta la actualidad. En estas páginas se describen las transformaciones que ha experimentado la tradición discursiva denominada pregón o bando. Por un lado, se revisa la información que ofrecen las obras lexicográficas a lo largo del tiempo respecto de bandos y pregones; por otro, se analizan diacrónicamente, a través de fuentes literarias y no literarias, la peculiar tensión entre escritura y oralidad, la estructura diplomático-textual y las manifestaciones de la deíxis, todas ellas características de esta tradición.
Transferencia pragmática en lenguas afines: español e italiano
Authors: Robles Garrote Pilar
Published: August 2018

El estudio que se expone en el presente artículo analiza un corpus de correos electrónicos de petición en español e italiano L1 y L2 y tiene por objetivo estudiar el uso de las estrategias de cortesía verbal y comprobar la presencia o ausencia de transferencia pragmática en la interacción escrita de aprendientes italófonos de español L2. Los resultados indican que, si bien las muestras en L1 comparten ciertas características, en diferentes registros presentan discordancias en el uso de las estrategias de cortesía y confirman la presencia de transferencia pragmática en las muestras en L2 analizadas.
El sustantivo cuantificador en la lingüística hispánica: revisión crítica y nueva propuesta
Authors: San Julián Solana Javier
Published: August 2018

La incorporación de la etiqueta terminológica sustantivo cuantificador (o cuantificativo) a la lingüística hispánica es reciente, y su difusión, todavía escasa. Además, se trata de un marbete carente de univocidad, pues aparece ligado a distintos conceptos a lo largo de la bibliografía. Así las cosas, el objetivo del presente artículo es triple: 1) repasar el tratamiento que han recibido los cuantificadores de categoría sustantiva en los estudios gramaticales del español; 2) analizar críticamente las concepciones previas, poniendo de relieve los inconvenientes que ofrecen; y 3) proponer una nueva noción que salve los problemas previamente señalados.
La expresión evidencial con 'así que': significado evidencial y función discursiva en la interacción
Authors: Sainz Eugenia
Published: August 2018

En el presente artículo se focaliza la atención en el tipo de enunciado evidencial introducido por la conjunción ilativa así que (Rodríguez Ramalle 2010, 2013, 2014a, 2014b, 2015, 2016). En primer lugar, se describe el significado evidencial integrando las nociones de fuente y de acceso indirecto o mediado (Lazard 1999, 2001) con la noción interactiva de intersubjetividad (Nuyts 2001a, 2001b, 2006, 2012). En segundo lugar, se justifica la aparición del significado evidencial a partir de la hipótesis de una instrucción polifónica evidencial (Ducrot 1980, 1984). Por último, desde el punto de vista funcional, analizamos la función del enunciado evidencial en la interacción oral integrando la hipótesis de justificación de Anderson 1986 con las nociones pragmáticas de deixis proposicional (de Haan 2005), autoridad, derecho y propiedad de la información (Fox 2011, Hill and Irvine 1983, Nucholls y Michael 2014) y en relación con los fenómenos pragmáticos de la atenuación y de la intensificación (Briz 2003, 2007, 2011, 2016; Briz y Albelda 2013; Albelda 2016). Los datos manejados sostienen la independencia de las categorías evidencial y epistémica así como el valor deíctico de los evidenciales.
Arquitecturas Salvajes. Etnoarqueología de las viviendas nilo-saharianas de Etiopía Occidental
Authors: Falquina Álvaro
Published: August 2018

Se lleva a cabo un análisis etnoarqueológico de las viviendas de las comunidades nilo-saharianas de Etiopía Occidental. El objetivo es mostrar que las casas de estas comunidades tienen un modelo espacial común, sobre el que se han desplegado diferentes variantes en la configuración interior de las casas a lo largo de su historia, incluso dentro de un mismo grupo étnico. Este modelo espacial común se materializa un tipo de casa que ordena las acciones y prácticas sociales de humanos y cosas siguiendo los principios fisiológicos del cuerpo humano.
O ouro em Gana no século XXI: escalas e origens do capital na mineração aurífera
Authors: Lopes dos Santos Kauê
Published: August 2018

A mineração é uma das mais importantes atividades econômicas de muitas formações socioespaciais africanas. Nesse contexto, explorado há séculos na África Ocidental, o ouro tornou-se, no século XXI, o principal produto da pauta de exportações de Gana, sendo extraído e processado principalmente por grandescapitais estrangeiros e por pequenos capitais nacionais, que estabelecem diversos tipos de relações no país. Na cadeia produtiva desse minério, atua ainda o Estado, responsável pela elaboração da legislação e da fiscalização no setor. Assim, compreender a organização das forças produtivas e das relações de produção emtorno da exploração aurífera contemporânea de Gana é o objetivo deste artigo.
As geotecnologias na geografia acadêmica e na geografia escolar e seus desdobramentos educativos
Authors: Cazetta Valéria
Published: August 2018

O propósito deste texto é pensar com as linguagens cartográfica e do Sensoriamento Remoto a composição de um campo de forças indissociável do pensamento do espaço e da corporeidade, bem como seus paradoxos. Perspectivados desde uma analítica micropolítica, no registro deleuze-guattariano, elementos da cartografia simbólica como escala, projeção e simbologia foram empregados para operar com os mapas e com as imagens tributárias do Sensoriamento Remoto, objetivando compreender o espaço e a corporeidade de modo multiescalar. Assim, produzimos cruzamentos desde uma analítica micropolítica entre práticas educativas junto a escolares, com idade entre 9 e 10 anos, do ensino fundamental 1 da educação básica, especificamente quarto ano; e estudantes de graduação da Licenciatura em Ciências da Natureza (LCN) da Escola de Artes,Ciências e Humanidades (EACH) – Universidade de São Paulo (USP).
Sedimentos tecnogênicos em planície aluvial em Presidente Prudente?SP
Authors: Cristina Nesta Silva Érika , Osvaldo Rodrigues Nunes João
Published: August 2018

As deposições tecnogênicas apresentam características diferentes conforme o local onde são formadas. Este artigo apresenta contribuições relevantes quanto à interpretação dos materiais sedimentares tecnogênicos, especialmente na fração areia (entre 0,053mm e 2mm), estudados numa área de planície aluvial de Presidente Prudente – SP. Com o objetivo de reconhecer os materiais presentes nas deposições e relacioná-los às prováveis fontes, realizou-se a coleta de amostras, identificação visual dos materiais nos amostradores, análises granulométricas, fracionamentos da fração areia e microscopia ótica. Conforme esses procedimentos, reconheceu-se a presença de fragmentos de queimadas, plásticos, materiais de construção e nódulo carbonático. Esses materiais foram relacionados com o histórico de uso e ocupação e foram observadas as dificuldades de identificação de alguns desses materiais como manufaturados, visto a semelhança visual com fragmentos do embasamento rochoso local (arenitos da Formação Adamantina, Grupo Bauru). Concluise que a presença de fragmentos de carvão em camadas profundas se relaciona às queimadas realizadas durante as primeiras fases de expansão agrícola na região e os materiais manufaturados originam-se da área do loteamento e do antigo depósito de resíduos sólidos domésticos.
Avaliação dos efeitos do adensamento urbano na dinâmica hidrológica de bacias hidrográficas – Aparecida de Goiânia – GO
Authors: Dias Nunes Elizon , Lima Borba Lana
Published: August 2018

A expansão e o adensamento urbano nas últimas quatro décadas influenciaram na dinâmica hidrológica de bacias hidrográficas urbanas. O objetivo deste trabalho é avaliar a intensificação desse processo, tendo como base mudanças nos coeficientes de escoamento superficial em face de cenários de precipitação, esua influência no aumento das estimativas de vazão de uma bacia hidrográfica em Aparecida de Goiânia. A metodologia consistiu na modelagem dos condicionantes por geoprocessamento, envolvendo precipitação, variáveis morfométricas, classes de cobertura e uso associadas aos tipos de solo, e seus efeitos nasestimativas de vazão em 1992, 2005 e 2016. Os resultados indicam uma estreita correlação espaço-temporal entre o adensamento urbano e as estimativas de vazão, sendo que, no exutório da bacia, a vazão máxima estimada passou de 16,2 em 1992 para cerca de 46,8 m³/s em 2016. No mesmo período e em toda a bacia, a redução do tempo de concentração foi de apenas 5,3 minutos, em contraste com o considerável aumentodas estimativas de velocidade de escoamento das áreas densamente edificadas. Entende-se que os canais, juntamente com a planície de inundação, funcionaram como áreas redutoras da velocidade de escoamento, intensificadas pelo aumento e pela convergência de volumes de fluxo advindos das áreas mais elevadas.
Fair Value and Abnormal Audit Fees
Authors: Ryabova Tatyana S , Chen Keji , Taylor Gary , Vedd Rishma
Published: August 2018

Our study compares the financial reporting quality between a principles-based (i.e., fair value) and a rules-based (i.e., historical cost) accounting system. We explore a non-market based proxy of financial reporting quality: abnormal or unexplained audit fees. Utilizing a sample of European Union firms, we find that firms using a fair value accounting system have a lower level of abnormal audit fees. This result provides preliminary evidence that a fair value accounting system provides higher financial reporting quality.