Acculturation et dénomination des langues africaines

Nombreuses sont les langues africaines qui, à l’heure actuelle, connaissent deux dénominations, l’une donnée par le colonisateur européen, l’autre, plus récemment, par les langagiers. Tandis que la première paraît étrangère en raison du processus de transcription, la seconde se veut authentique et fait appel aux ressources de la langue elle-même. L’étude présente cet état de fait pour trois langues d’Afrique de l’Ouest et montre que ces dénominations ne tiennent pas compte du nom de la langue en usage dans la langue elle-même, qu’elles sont des abus de langage et qu’elles résultent, en fait, d’une imposition, à la langue, de la culture du colonisateur ou de celle des langagiers.At the present time, several African languages have two names, the first one being given by the european colonizer, the other one, more recently, by language professionals and researchers. The first denomination looks foreign due to the transcription process, the second is intended to be authentic. This study analyses such a situation for three West African languages and shows that the names used in the languages themselves have been ignored. In fact, the denominations of both types have been imposed by the culture of the colonizer and by that of the linguists

Rathke cleft cyst with squamous metaplasia and activating mutations of mitogen-activated protein kinase signaling: illustrative case.

BACKGROUND: Rathke cleft cysts (RCCs) are benign sellar/suprasellar lesions that result from mucin-secreting vestigial remnants within the pars intermedia of the pituitary gland. When symptomatic, they can present with retro-orbital headaches, visual field defects, and/or pituitary dysfunction. OBSERVATIONS: A 35-year-old female presented with subacute retro-orbital headache, right ptosis, and blurred vision. Workup revealed panhypopituitarism with central hypothyroidism and adrenal insufficiency. Imaging demonstrated a sellar/suprasellar mass with subacute intralesional hemorrhage, which was thought to represent chronic pituitary apoplexy. The patient underwent an endoscopic endonasal approach in which the initial intraoperative frozen section suggested papillary craniopharyngioma. Subsequent specimens suggested RCC, thus presenting a surgical management conundrum. Hemihypophysectomy with lesionectomy was performed. Final histopathology demonstrated RCC with squamous metaplasia (RCC-SM), rupture, and hemorrhage. BRAF V600E was not detected. However, activating mutations in KRAS and MAP2K1 were identified. LESSONS: RCC can undergo SM and rupture, leading to a hemorrhagic-appearing cystic sellar/suprasellar mass associated with cranial nerve palsies and hypopituitarism that mimics pituitary apoplexy. Intraoperative frozen sections can be ambiguous due to overlapping histopathological features with craniopharyngioma, complicating surgical decision-making. The authors hypothesize that RCC-SM may represent a transitional state between RCC and craniopharyngioma. Neurosurgeons should be mindful of this transitional entity and be prepared to modify their surgical strategy accordingly. https://thejns.org/doi/10.3171/CASE24657

Enhanced Bandwidth of Band Pass Filter Using a Defected Microstrip Structure for Wideband Applications

In this paper, the bandwidth enhancement of bandpass filter (BPF) is proposed by utilizing defected microstrip structure (DMS). The initial micro strip BPF which is designed to have the bandwidth 1GHz with the center frequency of 3.5GHz is deployed on FR4 Epoxy dielectric substrate with overall size and thickness of 14mm x 24mm and 1.6mm, respectively. The proposed filter consists of two parallel coupled lines centred by ring-shaped, to enhance the bandwidth response, an attempt is carried out by applying DMS on the ligne center with a ring-shaped of initial filter. Here, the proposed DMS is constructed of the arrowhead dumbbell. Some parametrical studies to the DMS such as changing to obtain the optimum geometry of DMS with the desired bandwidth response. From the characterization result, it shows that the utilization of DMS on to the microstrip ligne of filter has widened 3dB bandwidth response up to 1.8GHz ranges from 2.55GHz to 4.35GHz yielding an enhanced wideband response for various wideband wireless applications

Oer catalysis at activated and codeposited nife-oxo/hydroxide thin films is due to postdeposition surface-fe and is not sustainable without fe in solution

This work examines by electrochemical measurements a hypothesis that low-coordination Fe on the surface (surface-Fe) of NiFe-oxo/hydroxide promotes catalysis for the oxygen evolution reaction (OER) rather than Fe in the bulk structure (bulk-Fe) even in ultrathin films that are mostly surface. The effect of method of incorporation of Fe in Ni-oxo/hydroxide on the electrochemical behavior and OER activity is interrogated, and the sustainability of OER catalysis at NiFe-oxo/hydroxide is examined in the absence of Fe in solution. Ni(Fe)-oxo/hydroxide ultrathin films of a few monolayers and thicker films of tens of monolayers of Ni(OH)2 were deposited at anodic bias from potassium borate buffer containing Ni nitrate or Ni and Fe nitrates at a 6:4 Ni:Fe ratio and were conditioned and studied in 1 M KOH containing Fe or purified from Fe. Fe was incorporated in NiFe-oxo/hydroxide during codeposition but removed from solution during conditioning and catalysis, was included postdeposition during conditioning and catalysis in Fe-containing solution, or was incorporated postdeposition by conditioning in Fe-containing solution and then removed from solution during catalysis. Ultrathin and thicker NiOxHy and Ni0.6Fe0.4OxHy films exhibited high OER currents and low Tafel slopes in the range of 40 mV/dec in 1 M KOH after activation that included Fe from solution. However, ultrathin and thicker codeposited Ni0.6Fe0.4OxHy films exhibited low OER currents in Fe-purified KOH, which further decreased with the application of anodic bias, and exhibited high Tafel slopes of ca. 100 mV/dec or higher, in a behavior similar to that of NiOxHy in Fe-free KOH. Fe included postdeposition or surface-Fe is therefore indicated to be responsible for high OER catalysis in ultrathin and thicker NiFe-oxo/hydroxide films. The sustainability of OER catalysis at postdeposition activated Ni(Fe)-oxo/hydroxide still required the presence of Fe in solution. NiOxHy films activated for OER postdeposition in Fe-containing electrolyte did not sustain their high OER catalysis in Fe-free KOH but were deactivated with potential cycling. An exchange that causes surface-Fe to move into higher coordination bulk-Fe is proposed to cause the loss of OER activity of activated NiFe-oxo/hydroxide in Fe-free electrolyte. © 2019 American Chemical Society

Enhanced Solar Light Harvesting with Q-CdTe/Se Sensitized Inverse Opal TiO2

This study reports enhanced light harvesting in an ultrathin Q-CdTe/Se quantum dot layer sensitized TiO2 photonic crystal that is enabled by light trapping which increases light absorbance in the photonic crystal structure. We fabricated TiO2 inverse opals (i-TiO2-o) with stop bands centered at ca. 550 nm (550-i-TiO2-o) sensitized with 2-4 nm Q-CdTe with absorption edges tuned to the red, within, and to the blue of the stop band, followed by surface modification with Se. The photoelectrode behavior was examined in the presence of an alkaline selenide electrolyte which enhances stability and efficiency, relative to the usual sulfide electrolyte. Modification with Se resulted in type-II Q-CdTe/CdSe characteristics of enhanced red-shifted absorbance and quenched emission, and a major increase in the light-to-current conversion was measured on both nc-TiO2 and i-TiO2-o after annealing attributed to improved charge separation across the Q-CdTe/CdSe interface. A 4-fold amplification was measured on average for i-TiO2-o sensitized with green-emitting 2.3 nm Q-CdTe to both the blue and red of the stop band relative to similarly sensitized nonscattering nc-TiO2, before and after Se-modification, which is attributed to light trapping amplifying absorbance. The gain is shown to depend on the absorption edge relative to the stop band; a smaller gain was measured for i-TiO2-o sensitized with 3 nm yellow-emitting Q-CdTe with an absorbance edge within the stop band. An enhancement by 4-5 fold in the overall visible photon-to-current-conversion efficiency resulted at i-TiO2-o sensitized with green-Q-CdTe/CdSe relative to similarly modified nc-TiO2: about 2-fold is attributed to the type-II structure and 2-fold to light trapping in the photonic crystal enhancing light absorbance by the layer of quantum dots. © 2020 American Chemical Society

Multijunction Photoanode of Mo:BiVO4Layered with TiO2Inverse Opal and NiBiOxygen Evolution Catalyst to Trap Light and Enhance Water Splitting

Thin-film photoelectrodes can benefit from mechanisms to trap light to increase absorbance and from multi-electron co-catalysts to facilitate charge transfer kinetics. This study examined photonic and catalytic effects in bismuth vanadate photoanodes coupled with a photonic crystal and oxygen evolution catalyst to enhance light energy conversion. A bilayer photoanode was fabricated by depositing a TiO2inverse opal (i-TiO2-o) with various stopbands, replicated from polystyrene opals assembled from 227, 282, and 305 nm spheres, on top of a thin Mo-doped BiVO4film. To assess photonic effects, the photoelectrochemical behavior was examined in the presence of sulfite sacrificial hole scavenger. An average gain in excess of twofold in the visible photon-to-current conversion efficiency was measured with i-TiO2-o having a stopband to the red of or coinciding with BiVO4absorbance. The effects of a heterojunction with TiO2and of disorder and the open structure were interrogated using a non-scattering nc-TiO2layer or a disordered TiO2inverse photonic glass (i-TiO2-g282) having the same air hole size as i-TiO2-o282, and neither was found to cause the gain. The periodicity was found to be key to enhance the photocurrent, and the gain is attributed to light trapping in different parts of the structure, increasing absorbance of bismuth vanadate coupled to the inverse opal. i-TiO2-o282on top of Mo:BiVO4also enhanced water photooxidation in borate buffer but to a lesser extent than with sulfite as the kinetics of oxygen evolution remains the predominant limitation. After modification with Ni(Fe)-oxo/hydroxo complex in borate (termed NiBi), the gain in the photon-to-current conversion efficiency reached twofold at the bilayer relative to the parent Mo:BiVO4. Photocurrents increased at low and high bias, which may be caused by reduced recombination and catalytic reactivity after hole transfer to the co-catalyst. Improved light harvesting upon coupling to the photonic crystal with a hole scavenger in solution or the oxygen evolution reaction catalyst on the surface was the highest for bismuth vanadate films that exhibited initially low light-to-current conversion efficiency, presenting a unique promise for thin photoelectrodes. © 2022 American Chemical Society. All rights reserved

Electrochemical study of the promoting effect of Fe on oxygen evolution at thin 'NiFe-Bi' films and the inhibiting effect of Al in borate electrolyte

In this study, we investigated the electrochemical effects of Fe co-deposition in thin Ni oxo/hydroxo films in borate, termed 'NiFe-Bi', electrodeposited from a Ni:Fe ratio of 9:1, 6:4, and 4:6 in solution. The NiFe-Bi films were investigated as-deposited and after anodic conditioning, and compared to Ni-Bi without intentional Fe doping at Ni(OH)2 loading from a submonolayer to 10 layers. Fe co-deposition enhanced the oxygen evolution reaction (OER) of as-deposited NiFe-Bi films relative to as-deposited Ni-Bi; however, anodic biasing was still required to maximize catalysis. The Ni(OH)2/NiOOH redox peaks of NiFe-Bi deposited from 6:4 and 4:6 Ni:Fe were more cathodic and more reversible than Ni-Bi peaks. Anodic conditioning caused the Ni(OH)2/NiOOH redox peaks of Ni-Bi and NiFe-Bi to shift anodically but without narrowing of peak separation, different from the effects of Fe co-deposition. After anodic conditioning, the turnover frequency (TOF) for OER per Ni center for Ni-Bi and NiFe-Bi was more proportional to the Ni content within the first linear Tafel region, with a promoting effect of Fe, and the films exhibited similar Tafel slopes of 37-42 mV dec-1. With increasing overpotential however, the TOF increased more significantly at high Fe:Ni ratio and was not proportional to the Ni content, and the Tafel slopes varied while notably decreasing for some NiFe-Bi films. Electrochemical results can support a Ni active site at low overpotential, but point to possibly different roles of Fe at low versus high potential. In addition, the effect of adding Fe3+ and Al3+ to the electrolyte was studied after deposition of Ni-Bi. Adding Fe resulted in reaching almost maximum activity in a single potential scan, confirming the promoting role of Fe in Ni-Bi and providing a quick alternative to applying anodic bias for hours to increase activity, while Al in the electrolyte poisoned OER catalysis at Ni-Bi and at NiFe-Bi. In the presence of both Fe and Al ions in solution however, with their opposite effects on the OER, the Ni(OH)2/NiOOH redox peaks shifted anodically with potential scanning. © The Royal Society of Chemistry 2017

Multiband Planar Inverted-F Antenna with Independent Operating Bands Control for Mobile Handset Applications

A new compact multiband PIFA (Planar Inverted-F Antenna) for mobile handset is proposed in this article. The proposed PIFA has a simple geometry with four slots integrated in the radiating patch and ground plane. The PIFA occupies a small volume of 51 × 14 × 7.2 mm3 and is placed on the top portion of mobile phone. The optimized PIFA is worked in the 790 MHz band (737–831 MHz), the 1870 MHz band (1794–1977 MHz), the 2550 MHz band (2507–2615 MHz), and the 3400 MHz band (3341–3545 MHz), to cover LTE700, LTE800, DCS1800, PCS1900, LTE1800, LTE1900, LTE2500, and WIMAX3400 bands. Each of the four operating bands can be controlled independently by the variation of a single parameter of the proposed design, with a wide control range. An omnidirectional radiation pattern to each resonant frequency is obtained with a maximum gain of 2.15 dBi at 790 MHz, 3.99 dBi at 1870 MHz, 4.57 dBi at 2550 MHz, and 6.43 dBi at 3400 MHz. The proposed PIFA is studied in the free space and in the presence of other mobile phone components such as the battery, LCD (liquid crystal display), camera, microphone, speaker, buttons, and a plastic housing. The distribution of specific absorption rate for both European and American standards for each operating band and at various distances between the antenna and the human head is also studied

A case of Bertolotti's syndrome as a cause of sciatica

Background: Bertolotti's syndrome (i.e., varying extent of fusion between the last lumbar vertebra and the first sacral segment) or lumbosacral transitional vertebrae is a rare cause of back pain. Notably, this syndrome is one of the differential diagnoses for patients with refractory back pain/sciatica. Case Description: A 71-year-old male presented with low back pain of 3 years duration that radiated into the right lower extremity resulting in numbness in the L5 distribution. He then underwent a minimally invasive approach to resect the L5 wide transverse process following the CT diagnosis of Bertolotti's syndrome. Prior to surgery, patient reported pain that was exacerbated by ambulation that resolved post-operative. Conclusion: Bertolotti's syndrome is one of the rare causes of sciatica that often goes undiagnosed. Nevertheless, it should be ruled out for patients with back pain without disc herniations or other focal pathology diagnosed on lumbar MR scans. © 2021 Scientific Scholar. All rights reserved