2,373 research outputs found
Molecular mechanisms of malaria sporozoite motility and invasion of host cells
Malaria sporozoites have the unique capacity to invade two entirely different types of target cell in the mosquito vector and the vertebrate host during the course of the parasite’s life cycle. Although little is known about the specific interaction of the sporozoite with its target cells, two sporozoite proteins, circumsporozoite (CS) and thrombospondin-related adhesive protein (TRAP), have been shown to play important roles in the invasion of both cell types. CS protein is a multifunctional protein involved in sporogony, invasion of the salivary glands, the specific arrest of sporozoites in the liver sinusoid, gliding motility of the sporozoite, and hepatocyte recognition and entry. TRAP has been shown to be critical for sporozoite infection of the mosquito salivary glands and liver cells, and is essential for sporozoite gliding motility. This review will focus on the involvement of these molecules in sporozoite motility and the invasion of host cells
Microbial dynamics during various activities in residential areas of Lahore, Pakistan
Bioaerosols are ubiquitous in the atmosphere with their levels affected by a variety of environmental factors as well as
type of activities being carried out at any specific time. The present study investigated how indoor activities influence
bioaerosol concentrations in five residential houses of Lahore. Agar coated petri plates were exposed face upwards for
twenty minutes in kitchens and living rooms during activity and non-activity periods. The temperature and relative
humidity levels were noted as well. The bioaerosol concentrations in kitchens during the activity time ranged between
1022 to 4481 cfu/m3 and in living rooms from 1179 to 3183 cfu/m3 . Lower values were observed during non-activity
periods. A paired-t test revealed a significant difference in bacterial loads during activity and non-activity times in both
micro-environments (p = 0.038 in kitchen and p = 0.021 in living room). The predominant species identified were
Micrococcus spp., Staphylococcus spp., and Bacillus spp. which are a common constituent of the indoor environment
and are known to be opportunistic pathogens as well
EFEK PENAMBAHAN SERAT POLYPROPYLENE TERHADAP KUAT TEKAN BETON PADA PERKERASAN KAKU
Rigid pavement or cement concrete pavement is a construction (pavement) with aggregate and raw materials and uses cement as a binding material. Rigid pavements have good compressive strength, but in contrast to flexural strength, this is due to their brittle nature, so when planning rigid pavements, fiber is added to the concrete mixture in the hope of increasing the elastic or flexible properties of the rigid pavement itself. This study aims to analyze the effect of adding polypropylene fibers to a mixture of rigid pavement concrete with a variation of 0.1%; 0.3%; 0.5%; 0.7%; and 1.0% by weight of cement. Control test objects without using polypropylene fiber. The number of cylindrical specimens of 15x30 cm was 30 pieces. Compressive strength test. The results showed that the compressive strength were optimum at 0.30%.Perkerasan kaku atau perkerasan beton semen adalah konstruksi (perkerasan jalan) dengan agregat dan bahan baku serta menggunakan semen sebagai bahan pengikat. Perkerasan kaku memiliki kuat tekan yang baik, namun berbeda dengan kuat lentur, hal ini dikarenakan sifatnya yang getas, sehingga pada saat merencanakan perkerasan kaku, ditambahkan serat pada campuran beton dengan harapan dapat meningkatkan sifat elastis atau lentur dari perkerasan kaku itu sendiri. Penelitian ini bertujuan menganalisis pengaruh penambahan serat polypropylene pada campuran beton perkerasan kaku dengan variasi 0,1%; 0,3%; 0,5%; 0,7%; dan 1,0% berat semen. Benda uji tanpa menggunakan serat polypropylene sebagai benda uji kontrol. Jumlah benda uji berbentuk silinder 15x30 cm sebanyak 30 buah. Uji kuat tekan Hasil penelitian menunjukkan bahwa kuat tekan optimum pada kadar serat polypropylene 0,30% terhadap berat seme
A GIS Based Digital Land Resources Framework for Optimal Soil Management in Barda and Awaje Basin, Syria
Kalman Filter of Dynamic Hierarchical Model
In a specific way, the dynamic hierarchical model has been presented alongside with the derivation of the final formula of the Kalman filter. The filtering coefficient used along with the equations necessary for the filtering process has also been determined. Most of the related works were studied which gave rise to the problem statement of filtering problems placed under the case of st = . Most of the basic concepts of the dynamic hierarchical linear model were also displayed based on some previous works. A mathematical formula was also formulated and derived to calculate the dynamic hierarchical Kalman filter model, which results in a repetitive measure to estimate the model parameters. The proposed derived formula reduces the error associated with the model and achieves a successful optimal estimation of the parameters. This proves that the Kalman coefficient is the best filtering for any normal probability distribution and provides the least variance among the estimates. This study also provides an illustrative example of the model with the filtering process concerned. It was further illustrated that the findings can be used in practical applications, which reveals the fields that can be investigated in this area
Simulating Cotton Growth and Productivity Using AquaCrop Model under Deficit Irrigation in a Semi-Arid Climate
AquaCrop is a water-driven model that simulates the effect of environment and management on crop production under deficit irrigation. The model was calibrated and validated using three databases and four irrigation treatments (i.e., 100%ET, 80%ET, 70%ET, and 50%ET). Model performance was evaluated by simulating canopy cover (CC), biomass accumulation, and water productivity (WP). Statistics of root mean square error (RMSE) and Willmott’s index of agreement (d) showed that model predictions are suitable for non-stressed and moderate stressed conditions. The results showed that the simulated biomass and yield were consistent with the measured values with a coefficient of determination (R2) of 0.976 and 0.950, respectively. RMSE and d-index values for canopy cover (CC) were 2.67% to 4.47% and 0.991% to 0.998% and for biomass were 0.088 to 0.666 ton/ha and 0.991 to 0.999 ton/ha, respectively. Prediction of simulated and measured biomass and final yield was acceptable with deviation ˂10%. The overall value of R2 for WP in terms of yield was 0.943. Treatment with 80% ET consumed 20% less water than the treatment with 100%ET and resulted in high WP in terms of yield (0.6 kg/m3) and biomass (1.74 kg/m3), respectively. The deviations were in the range of −2% to 11% in yield and −2% to 4% in biomass. It was concluded that AquaCrop is a useful tool in predicting the productivity of cotton under different irrigation scenarios
Dielectric Properties and AC conductivity of (Epoxy / Ion exchange) blend
The dielectric behavior of blend materials epoxy resin- Polyvinyl benzyl dimethyl ethanol ammonium chloride (PBDEAC) (Ion exchange) was analysed as a function of Ion exchange weight content; temperature and frequency. Blends were prepared by mixing the components and pouring them into suitable moulds. The dielectric parameters have been measured using parallel plate capacitor method in the frequency range from 120 Hz to 2 MHz and in the temperature range from 30 ?C to 110?C. Variations of real (??) and imaginary (?") parts of dielectric constants and loss tangent of material with frequency and temperature have been studied. The experimental results showed that (??) and (?") increased with the addition of Ion exchange filler content. The value of (??) decreased with increasing frequency, which indicates that the major contribution to the polarization comes from orientation polarization. Dielectric loss peaks were also observed in the composite materials at high temperature. The value of (??) increased with increasing temperature, and is due to greater freedom of movement of the dipole molecular chains within the polymer at high temperature. Ac. conductivity and impedance of the composites behaviours as function of frequency and temperature have also been investigated. Keywords: Dielectric properties, epoxy, Ion exchange, ac. conductivity
Editorial: EBV-Associated Carcinomas: Presence, Role, and Prevention Strategies.
This special issue addresses an important topic related to the role of Epstein-Barr virus (EBV) in human carcinomas initiation and progression, which is one of the most common viral infections worldwide. Today, the relationship between EBV infection and several types of human lymphomas is clearly established, including Hodgkin and Burkitt's lymphoma; meanwhile, it was recently pointed out that EBV is present in nasopharyngeal carcinomas as well as other epithelial cancers (1). EBV is ubiquitous human herpesvirus 4, its genome codes more than 85 proteins of which only few are well-understood; More specifically, six nuclear antigens (EBNA: 1, 2, 3A, 3B, 3C, and LP); three latent membrane proteins/genes (LMP: 1, 2A, 2B) as well as small non-polyadenylated RNAs, EBERs 1 and 2 in addition to few microRNAs have been identified so far, as key regulators, of the oncogenic activity of this virus (2, 3). Present estimates indicate that EBV causes 200,000 new cancer cases annually, accounting for ~2% of cancers worldwide (Cancer Research UK). On the other hand, it is important to emphasize that recent investigations have revealed the possible involvement of EBV in other cancers such as cervical, gliomas, and breast, which are highlighted in this issue.This work is supported by Qatar University grants# GCC-2017-002 QU/KU and QUCG-CMED-20182019-3
Performance investigation of stand-alone induction generator based on STATCOM for wind power application
Self-Excited induction generators (SEIG) display a low voltage and frequency regulation due to variable applied load and input rotation speed. Current work presents a simulation and performance analysis of a three-phase wind-driven, SEIG connect to a three-phase load. In addition, an investigation of the dynamic operation of the induction generator from starting steady state until no-load operation. It is assumed that the input mechanical power is constant where the rotor of the SEIG rotates at a constant speed. The value of the excitation capacitance which is necessary to the operation of the induction generator also computed to ensure a smooth and self-excitation starting. The output voltage of the generator is adjusted by varying the reactive power injected by STATCOM. A 3-phase IGBT voltage source inverter with a fuel cell input supply is connected as STATCOM which is used to compensate for the reduction in the supply voltage and its frequency due to variation occurred in the applied loads. This work includes introducing a neuro-fuzzyy logic controller to enhance the performance of the SEIG by regulation the generated voltage and frequency The dynamic model of SEIG with STATCOM and loads are implemented using MATLAB/SIMULIN
Aorto-Uni-Iliac Stent Grafts with and without Crossover Femorofemoral Bypass for Treatment of Abdominal Aortic Aneurysms: A Parallel Observational Comparative Study
We investigated the safety and efficacy of primary aorto-uni-iliac (AUI) endovascular aortic repair (EVAR) without fem-fem crossover in patients with abdominal aortic aneurysm (AAA) and concomitant aortoiliac occlusive disease. 537 EVARs were implemented between 2002 and 2015 in University Hospital Galway, a tertiary referral center for aortic surgery and EVAR. We executed a parallel observational comparative study between 34 patients with AUI with femorofemoral crossover (group A) and six patients treated with AUI but without the crossover (group B). Group B patients presented with infrarenal AAAs with associated total occlusion of one iliac axis and high comorbidities. Technical success was 97% (n=33) in group A and 85% (n=5) in group B (P=0.31). Primary and assisted clinical success at 24 months were 88% (n=30) and 12% (n=4), respectively, in group A, and 85% (n=5) and 15% (n=1), respectively, in group B (P=0.125). Reintervention rate was 10% (n=3) in group A and 0% in group B (P=0.084). No incidence of postoperative critical lower limb ischemia or amputations occurred in the follow-up period. AUI without crossover bypass is a viable option in selected cases
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