Addition-Deletion Networks

We study structural properties of growing networks where both addition and deletion of nodes are possible. Our model network evolves via two independent processes. With rate r, a node is added to the system and this node links to a randomly selected existing node. With rate 1, a randomly selected node is deleted, and its parent node inherits the links of its immediate descendants. We show that the in-component size distribution decays algebraically, c_k ~ k^{-beta}, as k-->infty. The exponent beta=2+1/(r-1) varies continuously with the addition rate r. Structural properties of the network including the height distribution, the diameter of the network, the average distance between two nodes, and the fraction of dangling nodes are also obtained analytically. Interestingly, the deletion process leads to a giant hub, a single node with a macroscopic degree whereas all other nodes have a microscopic degree.Comment: 8 pages, 5 figure

Myxome Du Maxillaire A Propos D\'un Cas

Les myxomes des maxillaires sont des tumeurs bénignes rares dont la pathogénie reste encore controversée. Leur indolence et la pauvreté des manifestations qui les accompagnent rendent leur diagnostic souvent tardif et leur prise en charge difficile. Nous présentons un cas de myxome du maxillaire chez un nourrisson âgé de 12 mois suivi d\'une revue de la littérature permettant de synthétiser les données cliniques ainsi que la stratégie thérapeutique à adopter.Maxillary myxoma are rare benign tumours whose pathogenesis remains extremely discussed. The poor clinical picture and the absence of pain makes the diagnosis difficult. We report a pediatric case of maxillary myxoma of a 12- monthold infant and review the clinical features, radiographic evaluation and the appropriate treatment Keywords:Myxoma - maxillary - benign tumor. Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 18 2007: pp. 43-4

Cholesteatome Congenital De L’oreille Moyenne A Propos De Deux Cas

But :Le cholesteatome congenital de l’oreille moyenne est une entite rare. L’objectif de ce travail est de discuter les particularites cliniques et therapeutiques de cette pathologie a travers deux observations de malades presentant un cholesteatome congenital operes et suivis au service d’ORL et de chirurgie cervico-faciale Fattouma Bourguiba Monastir, entre 2002 et 2008. Résultats : Il s’agissait de deux garcons, ages de 5 et 7 ans. La symptomatologie etait dominee par l’apparition d’une hypoacousie et l’examen otologique a revele un tympan complet dans les deux cas. La TDM des rochers a permis d’evoquer le diagnostic du cholesteatome congenital et d’apprecier les extensions locales des lesions. Les deux malades ont eu une tympanoplastie en technique fermee. Conclusion : L’evolution du cholesteatome congenital est insidieuse et le diagnostic est souvent tardif. Le traitement est chirurgical, domine par la tympanoplastie en technique fermee. Mots clès : Chlolesteatome congenital, hypoacousie, tympan complet, tympanoplastie en technique fermee, technique ouverte

Tumeur Germinale De L\'espace Para Pharynge : A Propos D\'un Cas

Les tumeurs germinales à localisation cervico-faciale sont rares. Nous rapportons l\'observation d\'une une fillette de 7 ans porteuse d\'une tumeur maligne à cellules germinales de l\'espace para-pharyngé droit traité par chimiothérapie. Les particularités étiopathogéniques, thérapeutiques, et pronostiques de cette tumeur sont rappelées après une revue des données de la littérature.Extragonadal germ cell tumors of the head and neck are very rare. We report the case of a 7-year-old girl with malignant germ cell tumor of the right parapharyngeal space treated by chemotherapy. Etiopathogenic, therapeutic, and prognostic characteristics of this tumour are recalled after a review of the literature data. Keywords: Extragonadal germ cell tumors, parapharyngeal tumors. Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 18 2007: pp. 61-6

Design of a Partially Grid-Connected Photovoltaic Microgrid Using IoT Technology

This study describes the design and control algorithms of an IoT-connected photovoltaic microgrid operating in a partially grid-connected mode. The proposed architecture and control design aim to connect or disconnect non-critical loads between the microgrid and utility grid. Different components of the microgrid, such as photovoltaic arrays, energy storage elements, inverters, solid-state transfer switches, smart-meters, and communication networks were modeled and simulated. The communication between smart meters and the microgrid controller is designed using LoRa communication protocol for the control and monitoring of loads in residential buildings. An IoT-enabled smart meter has been designed using ZigBee communication protocol to evaluate data transmission requirements in the microgrid. The loads were managed by a proposed under-voltage load-shedding algorithm that selects suitable loads to be disconnected from the microgrid and transferred to the utility grid. The simulation results showed that the duty cycle of LoRa and its bit rate can handle the communication requirements in the proposed PV microgrid architecture

Research Output on Strategy Formulation and Implementation: Global Picture, Development and Key Bibliometric Indicators

Effective strategic management serves as the bedrock for an organization's vision, goal attainment, and stakeholder expectations. Consequently, the research focus on strategy formulation and implementation has garnered substantial attention in recent decades. This study aims to evaluate bibliometric indicators of research productivity related to strategy formulation and implementation through meticulous bibliometric analysis. The analysis leverages the R Bibliometrix library on scientific publications indexed in the Web of Science database. The dataset comprises 672 publications on strategy formulation and implementation, spanning the years 1971 to 2022. Authored by 1,280 contributors from 69 countries, these publications are dispersed across 374 diverse sources, including journals and books. Impressively, this body of work has garnered a cumulative total of 24,635 citations, averaging 36.66 citations per document. The top-ranking article, "The Resource-Based Theory of Competitive Advantage: Implications for Strategy Formulation" by Robert M. Grant, stands out with 3,649 citations. Examining global scientific production, the United States emerges as the primary contributor with 154 publications (22.91%), followed by China with 56 (8.33%) and the United Kingdom with 54 (8.03%). The study's findings offer valuable insights for researchers and organizations alike, shedding light on significant research contributions. This comprehensive assessment enables a nuanced understanding of the historical progression and growth within this domain. Additionally, it identifies current focal points of research and highlights areas that warrant attention in future studies

Biallelic mutations in valyl-tRNA synthetase gene VARS are associated with a progressive neurodevelopmental epileptic encephalopathy.

Aminoacyl-tRNA synthetases (ARSs) function to transfer amino acids to cognate tRNA molecules, which are required for protein translation. To date, biallelic mutations in 31 ARS genes are known to cause recessive, early-onset severe multi-organ diseases. VARS encodes the only known valine cytoplasmic-localized aminoacyl-tRNA synthetase. Here, we report seven patients from five unrelated families with five different biallelic missense variants in VARS. Subjects present with a range of global developmental delay, epileptic encephalopathy and primary or progressive microcephaly. Longitudinal assessment demonstrates progressive cortical atrophy and white matter volume loss. Variants map to the VARS tRNA binding domain and adjacent to the anticodon domain, and disrupt highly conserved residues. Patient primary cells show intact VARS protein but reduced enzymatic activity, suggesting partial loss of function. The implication of VARS in pediatric neurodegeneration broadens the spectrum of human diseases due to mutations in tRNA synthetase genes

The Dababiya corehole, Upper Nile Valley, Egypt : preliminary results

Author Posting. © Austrian Geological Society, 2012. This article is posted here by permission of Austrian Geological Society for personal use, not for redistribution. The definitive version was published in Austrian Journal of Earth Sciences 105, no. 1 (2012): 161-168.The Dababiya corehole was drilled in the Dababiya Quarry (Upper Nile Valley, Egypt), adjacent to the GSSP for the Paleocene/ Eocene boundary, to a total depth of 140 m and bottomed in the lower Maastrichtian Globotruncana aegyptiaca Zone of the Dakhla Shale Formation. Preliminary integrated studies on calcareous plankton (foraminifera, nannoplankton), benthic foraminifera, dinoflagellates, ammonites, geochemistry, clay mineralogy and geophysical logging indicate that: 1) The K/P boundary lies between 80.4 and 80.2 m, the Danian/Selandian boundary between ~ 41 and 43 m, the Selandian/Thanetian boundary at ~ 30 m (within the mid-part of the Tarawan Chalk) and the Paleocene/Eocene boundary at 11.75 m (base [planktonic foraminifera] Zone E1 and [calcareous nannoplankton] Zone NP9b); 2) the Dababiya Quarry Member (=Paleocene/Eocene Thermal Maximum interval) extends from 11.75 to 9.5 m, which is ~1 m less than in the adjacent GSSP outcrop.; 3) the Late Cretaceous (Maastrichtian) depositional environment was nearshore, tropical-sub tropical and nutrient rich; the latest Maastrichtian somewhat more restricted (coastal); and the early Danian cooler, low(er) salinity with increasing warmth and depth of water (i.e., more open water); 4) the Paleocene is further characterized by outer shelf (~ 200 m), warm water environments as supported by foraminifera P/B ratios > 85% (~79-28 m), whereas benthic foraminifera dominate (>70%) from ~27-12 m (Tarawan Chalk and Hanadi Member) due, perhaps, in part to increased dissolution (as observed in nearby outcrop samples over this interval); 5) during the PETM, enhanced hydrodynamic conditions are inferred to have occurred on the sea-floor with increased river discharge (in agreement with sedimentologic evidence), itself a likely cause for very high enhanced biological productivity on the epicontinental shelf of Egypt; 6) correlation of in situ measured geophysical logs of Natural Gamma Ray (GR), Single-Point Resistance (PR), Self-Potential (SP), magnetic susceptibility (MS), and Resistivity, and Short Normal (SN) and Long Normal (LN) showed correspondence to the lithologic units. The Dababiya Quarry Member, in particular, is characterized by very high Gamma Ray and Resistivity Short Normal values.The Dababiya corehole was made possible by the financial support of the National Geographic Society

Investigation of Changing Pore Topology and Porosity during Matrix Acidizing using Different Chelating Agents

Core flooding acidizing experiments on sandstone/carbonate formation are usually performed in the laboratory to observe different physical phenomena and to design acidizing stimulation jobs for the field. During the tests, some key parameters are analyzed such as pore volume required for breakthrough as well as pressure. Hydrochloric acid (HCl) is commonly used in the carbonate matrix acidizing while Mud acid (HF: HCl) is usually applied during the sandstone acidizing to remove damage around the well bore. However, many problems are associated with the application of these acids, such as fast reaction, corrosion and incompatibility of HCl with some minerals (illite). To overcome these problems, chelating agents (HEDTA, EDTA and GLDA) were used in this research. Colton tight sandstone and Guelph Dolomite core samples were used in this study. The experiments usually are defined in terms of porosity, permeability, dissolution and pore topology. Effluent samples were analyzed to determine dissolved iron, sodium, potassium, calcium and other positive ions using Inductively Coupled Plasma (ICP). Meanwhile Nuclear Magnetic Resonance (NMR) was employed to determine porosity and pore structure of the core sample. Core flood experiments on Berea sandstone cores and dolomite samples with dimensions of 1.5 in × 3 in were conducted at a flow rate of 1 cc/min under 150oF temperature. NMR and porosity analysis concluded that applied chemicals are effective in creating fresh pore spaces. ICP analysis concluded that HEDTA showed good ability to chelate calcium, sodium, magnesium, potassium and iron. It can be established from the analysis that HEDTA can increase more amount of permeability as compared to other chelates

The Regulation of Photosynthetic Structure and Function during Nitrogen Deprivation in Chlamydomonas reinhardtii

The accumulation of carbon storage compounds by many unicellular algae after nutrient deprivation occurs despite declines in their photosynthetic apparatus. To understand the regulation and roles of photosynthesis during this potentially bioenergetically valuable process, we analyzed photosynthetic structure and function after nitrogen deprivation in the model alga Chlamydomonas reinhardtii. Transcriptomic, proteomic, metabolite, and lipid profiling and microscopic time course data were combined with multiple measures of photosynthetic function. Levels of transcripts and proteins of photosystems I and II and most antenna genes fell with differing trajectories; thylakoid membrane lipid levels decreased, while their proportions remained similar and thylakoid membrane organization appeared to be preserved. Cellular chlorophyll (Chl) content decreased more than 2-fold within 24 h, and we conclude from transcript protein and 13C labeling rates that Chl synthesis was down-regulated both pre- and posttranslationally and that Chl levels fell because of a rapid cessation in synthesis and dilution by cellular growth rather than because of degradation. Photosynthetically driven oxygen production and the efficiency of photosystem II as well as P700+ reduction and electrochromic shift kinetics all decreased over the time course, without evidence of substantial energy overflow. The results also indicate that linear electron flow fell approximately 15% more than cyclic flow over the first 24 h. Comparing Calvin-Benson cycle transcript and enzyme levels with changes in photosynthetic 13CO2 incorporation rates also pointed to a coordinated multilevel down-regulation of photosynthetic fluxes during starch synthesis before the induction of high triacylglycerol accumulation rates