A Multiband Fractal Dipole Antenna for Wireless Communication Applications

mmunication applications. The proposed fractal antenna design is based onfractal geometry of the second level tent function transformation. Due to theresulting geometrical structures of a fractal tent function curve depend on thestarting angles of the initial tent function, many dipole antennas have beenmodeled and the corresponding radiation characteristics have been evaluated.Theoretical performance of these antennas has been calculated using the methodof moments (MoM) electromagnetic simulator, IE3D. Simulation results of manytent fractal dipole antennas which have been modeled show that all of theseantennas have multiband resonate behavior, but this resonate behavior is differentaccording to the starting angle for each antenna. The results have shown that theseantennas have acceptable performance for VSWR ≤ 2 (return loss ≤ -10 dB),using a 50W feed line, at most of the resonating frequencies. This feature providesantenna designer with more degree of freedom, and makes the proposed antenna(or its monopole counterpart) suitable for use in the modern multi-functionscommunication system

Loss of Niemann-Pick C1 or C2 Protein Results in Similar Biochemical Changes Suggesting That These Proteins Function in a Common Lysosomal Pathway

Niemann-Pick Type C (NPC) disease is a lysosomal storage disorder characterized by accumulation of unesterified cholesterol and other lipids in the endolysosomal system. NPC disease results from a defect in either of two distinct cholesterol-binding proteins: a transmembrane protein, NPC1, and a small soluble protein, NPC2. NPC1 and NPC2 are thought to function closely in the export of lysosomal cholesterol with both proteins binding cholesterol in vitro but they may have unrelated lysosomal roles. To investigate this possibility, we compared biochemical consequences of the loss of either protein. Analyses of lysosome-enriched subcellular fractions from brain and liver revealed similar decreases in buoyant densities of lysosomes from NPC1 or NPC2 deficient mice compared to controls. The subcellular distribution of both proteins was similar and paralleled a lysosomal marker. In liver, absence of either NPC1 or NPC2 resulted in similar alterations in the carbohydrate processing of the lysosomal protease, tripeptidyl peptidase I. These results highlight biochemical alterations in the lysosomal system of the NPC-mutant mice that appear secondary to lipid storage. In addition, the similarity in biochemical phenotypes resulting from either NPC1 or NPC2 deficiency supports models in which the function of these two proteins within lysosomes are linked closely

Activation Mobilizes the Cholesterol in the Late Endosomes-Lysosomes of Niemann Pick Type C Cells

A variety of intercalating amphipaths increase the chemical activity of plasma membrane cholesterol. To test whether intracellular cholesterol can be similarly activated, we examined NPC1 and NPC2 fibroblasts, since they accumulate large amounts of cholesterol in their late endosomes and lysosomes (LE/L). We gauged the mobility of intracellular sterol from its appearance at the surface of the intact cells, as determined by its susceptibility to cholesterol oxidase and its isotope exchange with extracellular 2-(hydroxypropyl)-β-cyclodextrin-cholesterol. The entire cytoplasmic cholesterol pool in these cells was mobile, exchanging with the plasma membrane with an apparent half-time of ∼3–4 hours, ∼4–5 times slower than that for wild type human fibroblasts (half-time ∼0.75 hours). The mobility of the intracellular cholesterol was increased by the membrane-intercalating amphipaths chlorpromazine and 1-octanol. Chlorpromazine also promoted the net transfer of LE/L cholesterol to serum and cyclodextrin. Surprisingly, the mobility of LE/L cholesterol was greatly stimulated by treating intact NPC cells with glutaraldehyde or formaldehyde. Similar effects were seen with wild type fibroblasts in which the LE/L cholesterol pool had been expanded using U18666A. We also showed that the cholesterol in the intracellular membranes of fixed wild-type fibroblasts was mobile; it was rapidly oxidized by cholesterol oxidase and was rapidly replenished by exogenous sterol. We conclude that a) the cholesterol in NPC cells can exit the LE/L (and the extensive membranous inclusions therein) over a few hours; b) this mobility is stimulated by the activation of the cholesterol with intercalating amphipaths; c) intracellular cholesterol is even more mobile in fixed cells; and d) amphipaths that activate cholesterol might be useful in treating NPC disease

Comparison Of Biochemical And Physiological Properties Of Nigerian Tomato Fruits Ripened Under Different Conditions

The growth in chronic diseases such as obesity, diabetes, various types of cancers and cardiovascular diseases is an argument in favour of promoting fruit and vegetable consumption in Africa, with the main obstacle being the purchasing power. The objective of this study was to investigate the respective impacts of ripening stages and techniques of ripening on tomato fruit quality in order to recommend which of the conditions of ripening is better for optimum benefit of the tomatoes. The physiological and biochemical changes in tomato fruits of two varieties (Ibadan-Local and Roma cultivars) ripened using two different techniques (field and ambient temperature ripening) were monitored; the differences in the mean values between the ripening methods are discussed at appropriate significance levels. The mean differences in percent total solids for tomato fruits between the two conditions of ripening are significant (P<0.05 at the breaker stage of Ibadan-local cultivar and P<0.01 for other stages in the two varieties). The differences are much higher at the pink to fully-red stages in tomatoes ripened under the ambient temperature. Except at light-red stage of Ibadan-local cultivar and breaker stage of Roma cultivar, the mean differences in pH values between the ripening methods are significant (P<0.05 at the breaker stage of Ibadan-local cultivar and at the light-red stage of Roma cultivar and P<0.01 for other stages in the two varieties).Mean differencesin percent titratable acidity (as citric acid) of the fruits under the two methods of ripening are also significant (P<0.05 at the breaker stage of Roma cultivar and P<0.01 for other stages in the two varieties) with exceptions at fully-red stage of the two varieties. However, high significant differences (P<0.01) exist between the mean values of reducing sugar, lycopene (but P<0.05 at breaker stage of Roma cultivars) and beta-carotene contents of the tomato fruits under the two conditions of ripening, with higher values obtained mostly in the field ripening method.About 69.2 g and 58.3 g of tomato fruits, ripened on the parent plants (field ripening), at light-red stage of Ibadan-local and Roma-type respectively, are recommended daily in accordance with average daily recommendation of 25.2 mg of lycopene per day in Canadian diet and from the study from Harvard School of Medicine. Equivalent quantities could only be reached by consuming higher quantities of tomatoes ripened at ambient temperature

KONKURENTNA PREDNOST NIGERIJSKE INDUSTRIJE OSIGURANJA: ULOGA INOVACIONE SPOSOBNOSTI

Emerging technologies have given rise to greater opportunities within the insurance sector with innovations upturning the traditional business model. This study examined competitive advantage and the relationship with innovation capability in Nigerian insurance sector. Employing a cross sectional research design, the study utilised primary data obtained from selected insurance companies through the use of a structured questionnaire. Multistage sampling technique was used and data collected was analysed using regression analysis. The findings revealed innovation capability had a significant influence on competitive advantage. The study concluded that there was a need to pay attention to this capability with a capacity to boost the activities of the industry and recommendations were made.Nove tehnologije su omogućile veće mogućnosti u okviru sektora osiguranja, gde su inovacije preokrenule tradicionalni biznis model. Ovaj rad proučava konkurentnu prednost i njen odnos sa sposobnošću za inovacije nigerijskog sektora osiguranja. Uz pomoć međusektorskog dizajna istraživanja, studija koristi primarne podatke dobijene od odabranih osiguravajućih kompanija uz pomoć strukturisanog upitnika. Korišćena je tehnika višefaznog uzrokovanja, a dobijeni podaci su analizirani uz pomoć regresivne analize. Rezultati su pokazali da je sposobnost za inovacije imala značajnog uticaja na komparativnu prednost. Studija zaključuje da postoji potreba da se obrati pažnja na ovu sposobnost sa mogućnošću da se pojačaju aktivnosti industriuje i date su preporuke

Impact of the COVID-19 pandemic on patients with paediatric cancer in low-income, middle-income and high-income countries: a multicentre, international, observational cohort study

OBJECTIVES: Paediatric cancer is a leading cause of death for children. Children in low-income and middle-income countries (LMICs) were four times more likely to die than children in high-income countries (HICs). This study aimed to test the hypothesis that the COVID-19 pandemic had affected the delivery of healthcare services worldwide, and exacerbated the disparity in paediatric cancer outcomes between LMICs and HICs. DESIGN: A multicentre, international, collaborative cohort study. SETTING: 91 hospitals and cancer centres in 39 countries providing cancer treatment to paediatric patients between March and December 2020. PARTICIPANTS: Patients were included if they were under the age of 18 years, and newly diagnosed with or undergoing active cancer treatment for Acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, Wilms' tumour, sarcoma, retinoblastoma, gliomas, medulloblastomas or neuroblastomas, in keeping with the WHO Global Initiative for Childhood Cancer. MAIN OUTCOME MEASURE: All-cause mortality at 30 days and 90 days. RESULTS: 1660 patients were recruited. 219 children had changes to their treatment due to the pandemic. Patients in LMICs were primarily affected (n=182/219, 83.1%). Relative to patients with paediatric cancer in HICs, patients with paediatric cancer in LMICs had 12.1 (95% CI 2.93 to 50.3) and 7.9 (95% CI 3.2 to 19.7) times the odds of death at 30 days and 90 days, respectively, after presentation during the COVID-19 pandemic (p<0.001). After adjusting for confounders, patients with paediatric cancer in LMICs had 15.6 (95% CI 3.7 to 65.8) times the odds of death at 30 days (p<0.001). CONCLUSIONS: The COVID-19 pandemic has affected paediatric oncology service provision. It has disproportionately affected patients in LMICs, highlighting and compounding existing disparities in healthcare systems globally that need addressing urgently. However, many patients with paediatric cancer continued to receive their normal standard of care. This speaks to the adaptability and resilience of healthcare systems and healthcare workers globally