Biologically-inspired transport of solid spherical nanoparticles in an electrically-conducting viscoelastic fluid with heat transfer

Bio-inspired pumping systems exploit a variety of mechanisms including peristalsis to achieve more efficient propulsion. Non-conducting, uniformly dispersed, spherical nano-sized solid particles suspended in viscoelastic medium forms a complex working matrix. Electromagnetic pumping systems often employ complex working fluids. A simulation of combined electromagnetic bio-inspired propulsion is observed in the present article. Currents formation has increasingly more applications in mechanical and medical industries. A mathematical study is conducted for magnetohydrodynamic pumping of a bi-phase nanofluid coupled with heat transfer in a planar channel. Two-phase model is employed to separately identity the effects of solid nanoparticles. Base fluid employs Jeffery’s model to address viscoelastic characteristics. The model is simplified using of long wavelength and creeping flow approximations. The formulation is taken to wave frame and non-dimensionalize the equations. The resulting boundary value problem is solved analytically, and exact expressions are derived for the fluid velocity, particulate velocity, fluid/particle temperature, fluid and particulate volumetric flow rates, axial pressure gradient and pressure rise. The influence of volume fraction density, Prandtl number, Hartmann number, Eckert number and relaxation time on flow and thermal characteristics is evaluated in detail. The axial flow is accelerated with increasing relaxation time and greater volume fraction whereas it is decelerated with greater Hartmann number. Both fluid and particulate temperature are increased with increment in Eckert and Prandtl number whereas it is reduced when the volume fraction density increases. With increasing Hartmann, number pressure rise is reduced. Furthermore, pressure is reduced with greater relaxation time in the retrograde pumping region whereas it is elevated in the co-pumping and free pumping regions. The number of the trapped boluses is decreased whereas the quantity of boluses increases with a rise in volume fraction density of particles

Aflatoxin B1 in chilies from the Punjab region, Pakistan

The occurrence of aflatoxin B1 (AFB1) in chilies from Pakistan was determined by using HPLC in work undertaken in Pakistan.Whole (n=22) and powdered (n=22) chilies were analyzed. Sixteen (73.0%) and 19 (86.4%) samples of whole and ground chilies, respectively, were contaminated. The mean concentration in powdered chilies (32.20 μg/kg) was higher statistically than in whole chilies (24.69 μg/kg). Concentrations ranged from 0.00 to 89.56 μg/ kg for powdered chilies, compared with 0.00–96.3 μg/kg for whole chilies. The limits of detection and quantification were 0.05 μg/kg and 0.53 μg/kg, respectively. The concentrations were high in general and greater than the statutory limit set by the European Union. There is considerable scope for improvements in chili production in Pakistan.Higher Education Commission, PakistanFundação para a Ciência e a Tecnologia (FCT

Optical coherence tomography findings in paraneoplastic pseudovitelliform lesions in melanoma-associated retinopathy

Michael Javaheri1, Rahul N Khurana1, Rizwan A Bhatti1, Jennifer I Lim21Doheny Retina Institute, Doheny Eye Institute, Department of Ophthalmology, University of Southern California, Keck School of Medicine, Los Angeles, CA, USA; 2Eye and Ear Infirmary, Department of Ophthalmology, University of Illinois, Chicago, IL, USAPurpose: To report an unusual case of paraneoplastic pseudovitelliform lesions associated with melanoma-associated retinopathy (MAR).Design: Observational case report.Methods: Retrospective review of the ophthalmic examination, fundus photography, fluorescein angiography, electroretinogram (ERG), and optical coherence tomography (OCT) of a patient with MAR.Results: A 65-year-old Caucasian man with a two-year history of metastatic melanoma was referred for evaluation of a six-month history of nyctalopia. Funduscopic examination in both eyes revealed multiple, creamy, yellow, pseudovitelliform lesions in the posterior pole, varying in size from 100–500 µm, at the level of the outer retinal/retinal pigment epithelium (RPE) junction, coalescing along the inferior portion, with overlying macular neurosensory detachments. OCT showed bilateral macular neurosensory detachments with multiple small areas of high refl ectivity at the level of the outer retinal/RPE junction. ERG demonstrated a selective loss of the b-wave and a normal a-wave under dark adapted, scotopic conditions.Conclusion: Clinicians should be aware of this atypical presentation of MAR that may include pseudovitelliform retinal findings.Keywords: cancer-associated retinopathy, melanoma-associated retinopathy, optical coherence tomography, paraneoplastic syndrome, paraneoplastic pseudovitelliform retinopath

Bacterial isolates from neutropenic febrile pediatric patients and their sensitivity patterns to antibiotics

Patients on cytotoxic therapy often develop neutropenia and fever. Our interest was to identify the common pathogens isolated from such patients and to study the sensitivity patterns of these organisms to the antibiotics used in their treatment. Thus, guidelines can be established by hospitals to identify which antibiotics can be used in the treatment of these patients when the results of cultures and sensitivities are not available. We conducted a retrospective study of neutropenic pediatrics presenting to AKUH from July, 1990 to June, 1996. A total of 153 isolates in 35 different patients were studied. Samples for culture were taken from the sites at risk. The majority of samples consisted of blood, stool, pus and urine. Twenty stool samples were also sent for microscopy. Malignancies were both hematological and non-hematological. Gram negatives were isolated in 52.9%, gram positives in 33.9% and parasites in 13.2%. Salmonella paratyphi B was the most commonly isolated organism, followed by Pseudomonas aeroginosa, Giardia lamblia was the most common parasite. Sensitivity patterns of these organisms to antibiotics studied showed that Escheria coli had the lowest sensitivity rate being only 40% sensitive to Aztreonam and 64% sensitive to Ofloxacillin. A comparison was made between our findings and those reported in literature, as well as the risk factors for developing neutropenia. A guide to management is also discussed

Stellar rotational periods in the planet hosting open cluster Praesepe

By using the dense coverage of the extrasolar planet survey project HATNet, we Fourier analyze 381 high-probability members of the nearby open cluster Praesepe (Beehive/M44/NGC 2632). In addition to the detection of 10 variables (of \delta Scuti and other types), we identify 180 rotational variables (including the two known planet hosts). This sample increases the number of known rotational variables in this cluster for spectral classes earlier than M by more than a factor of three. These stars closely follow a color/magnitude -- period relation from early F to late K stars. We approximate this relation by polynomials for an easier reference to the rotational characteristics in different colors. The total (peak-to-peak) amplitudes of the large majority (94%) of these variables span the range of 0.005 to 0.04 mag. The periods cover a range from 2.5 to 15 days. These data strongly confirm that Praesepe and the Hyades have the same gyrochronological ages. Regarding the two planet hosts, Pr0211 (the one with the shorter orbital period) has a rotational period that is ~2 days shorter than the one expected from the main rotational pattern in this cluster. This, together with other examples discussed in the paper, may hint that star-planet interaction via tidal dissipation can be significant in some cases in the rotational evolution of stars hosting Hot Jupiters.Comment: 17 pages, 13 figures, 5 tables; accepted for publication in MNRA

An energy efficient interference-aware routing protocol for underwater WSNs

Interference-aware routing protocol design for underwater wireless sensor networks (UWSNs) is one of the key strategies in reducing packet loss in the highly hostile underwater environment. The reduced interference causes efficient utilization of the limited battery power of the sensor nodes that, in consequence, prolongs the entire network lifetime. In this paper, we propose an energy-efficient interference-aware routing (EEIAR) protocol for UWSNs. A sender node selects the best relay node in its neighborhood with the lowest depth and the least number of neighbors. Combination of the two routing metrics ensures that data packets are forwarded along the least interference paths to reach the final destination. The proposed work is unique in that it does not require the full dimensional localization information of sensor nodes and the network total depth is segmented to identify source, relay and neighbor nodes. Simulation results reveal better performance of the scheme than the counterparts DBR and EEDBR techniques in terms of energy efficiency, packet delivery ratio and end-to-end delay

Ogbu and the debate on educational achievement: an exploration of the links between education, migration, identity and belonging

This paper looks at some of the issues raised by Ogbu’s work in relation to the education of different minority ethnic groups. Ogbu poses questions such as the value attached to education, its links to the future and its measurable outcomes in terms of ‘success’ as experienced by black participants. The desire for better life chances leads families to consider migration to a new country or resettlement within the same country, thus making migration both a local and a global phenomenon. As an example, attention is drawn to the situation facing South Asian children and their families in the UK. In terms of ethnicity and belonging, the wider question that is significant for many countries in the West after ‘Nine-Eleven’ is the education of Muslim children. A consideration of this current situation throws Ogbu’s identification of ‘autonomous minority’ into question. It is argued that a greater understanding of diverse needs has to be accompanied by a concerted effort to confront racism and intolerance in schools and in society, thus enabling all communities to make a useful contribution and to avoid the ‘risk’ of failure and disenchantment

Complications of in-dwelling venous access devices: a single institution experience

Objective: To determine the complications of venous access devices (VADs) in cancer patients.SETTING: Retrospective study in a tertiary referral center with specialist hematology and oncology services.SUBJECTS: First one hundred consecutive patients who were implanted a VAD. All patients had an underlying cancer and the devices were inserted by the same surgeon. The duration of use of VADs and causes of their premature removal were noted.Results: One hundred VADs (55 port-a-caths and 45 Hickman\u27s lines) were inserted in a total of 89 patients over a 7.5 year period. Majority of patients had acute myeloid leukemia (22) gastrointestinal malignancies (20) breast cancer (19) and genito-urinary cancers (15). The mean duration of use was 110 days; 157 days for the port-a-cath and 53 days for the Hickman\u27s line. Nineteen devices (10 port-a-caths and 9 Hickman\u27s lines) had to be removed prematurely. Two Hickman\u27s lines got removed accidentally. The causes of premature removal included device failure (9), exist site infection (4), luminal infection (3) and tunnel infection (3).CONCLUSION: The mean duration of use and the complication rates are comparable with studies reported in the literature