Melting dynamics of large ice balls in a turbulent swirling flow

We study the melting dynamics of large ice balls in a turbulent von Karman flow at very high Reynolds number. Using an optical shadowgraphy setup, we record the time evolution of particle sizes. We study the heat transfer as a function of the particle scale Reynolds number for three cases: fixed ice balls melting in a region of strong turbulence with zero mean flow, fixed ice balls melting under the action of a strong mean flow with lower fluctuations, and ice balls freely advected in the whole flow. For the fixed particles cases, heat transfer is observed to be much stronger than in laminar flows, the Nusselt number behaving as a power law of the Reynolds number of exponent 0.8. For freely advected ice balls, the turbulent transfer is further enhanced and the Nusselt number is proportional to the Reynolds number. The surface heat flux is then independent of the particles size, leading to an ultimate regime of heat transfer reached when the thermal boundary layer is fully turbulent

Can we screen for pancreatic cancer? Identifying a sub-population of patients at high risk of subsequent diagnosis using machine learning techniques applied to primary care data.

BACKGROUND: Pancreatic cancer (PC) represents a substantial public health burden. Pancreatic cancer patients have very low survival due to the difficulty of identifying cancers early when the tumour is localised to the site of origin and treatable. Recent progress has been made in identifying biomarkers for PC in the blood and urine, but these cannot be used for population-based screening as this would be prohibitively expensive and potentially harmful. METHODS: We conducted a case-control study using prospectively-collected electronic health records from primary care individually-linked to cancer registrations. Our cases were comprised of 1,139 patients, aged 15-99 years, diagnosed with pancreatic cancer between January 1, 2005 and June 30, 2009. Each case was age-, sex- and diagnosis time-matched to four non-pancreatic (cancer patient) controls. Disease and prescription codes for the 24 months prior to diagnosis were used to identify 57 individual symptoms. Using a machine learning approach, we trained a logistic regression model on 75% of the data to predict patients who later developed PC and tested the model's performance on the remaining 25%. RESULTS: We were able to identify 41.3% of patients 60 years were similarly identified at 17 months, with 65% sensitivity, 57% specificity and, 61% AUC. We estimate that combining our algorithm with currently available biomarker tests could result in 30 older and 400 younger patients per cancer being identified as 'potential patients', and the earlier diagnosis of around 60% of tumours. CONCLUSION: After further work this approach could be applied in the primary care setting and has the potential to be used alongside a non-invasive biomarker test to increase earlier diagnosis. This would result in a greater number of patients surviving this devastating disease

Characterization of a Thin Film Composite Membrane: Fluorinated Copolymer in a Carbon Nanotube Matrix

IDEX Health and Science has created a thin-film composite membrane consisting of a carbon nanotube matrix impregnated with a fluorinated copolymer called Teflon® AF 2400. This membrane is being studied for use in degassing chambers of analytical instruments such as a High Pressure Liquid Chromatography (HPLC) degassing modules. The level of impregnation of the Teflon® in the carbon matrix affects the diffusion properties which are crucial for the performance of the membrane. Scanning Electron Microscopy (SEM) characterization techniques were used to measure the outer Teflon® and the inner carbon matrix layer thickness. The outer Teflon® and inner carbon matrix layer thicknesses ranged from 1.92 to 28.17 microns and 5.07 to 41.70 microns, respectively. Energy Dispersive X-ray Spectrometry (EDS) was used to measure the Teflon® fluorine concentration gradient across the composite membrane. Mechanical tensile testing was also performed on each sample to compare the mechanical properties of the membrane to the initial design parameters. Ultimate Tensile Strength (UTS), Young’s Modulus (E), and Percent Elongation were collected for each membrane. IDEX Health and Science used the following processing parameters to create each membrane: (a) Concentration, (b) Density, (c) Time, and (d) Recoat. Statistical analysis indicated that time and recoat had the largest effect on maximum stress at maximum load. The results from SEM imaging, EDS scans, and tensile testing helped determine how well the Teflon® infiltrated the carbon matrix. The interactions between the four processing parameters provided IDEX Health and Science with information to determine the optimal set of processing parameters for generating the ideal membrane

Effet de la fertilité du sol et du stress hydrique sur Banana Bunchy Top Disease

Early detection is important for the management of the Banana Bunch Top Disease (BBTD) as it enables the removal of inoculum and hence propagation of the disease. Roguing has been demonstrated as an effective way of managing BBTD if done consistently and in time. Disease detection is however dependent on the clear expression of the disease and its relationship with the onset of secondary spread from newly infected plants. Seasonal variations in BBTD cases observed in fields has been reported previously. This study investigated the effect of water stress and nutritional status of the soil on the expression of BBTD in two cultivars of Banana: FHIA 25 (hybrid) and a local landrace cultivar, Soutoumon. The two had previously been shown to differ in their response to symptom development. In brief we observed a delay in BBTD symptom expression associated with water stress under low fertility for both cultivars. Similar to previous reports, FHIA expressed the disease earlier than Soutoumon. Note: The poster is presented in Frenc

Ovarian profile of Wistar rats treated with Theobroa cacao extract.

The study was aimed at determining the effect of aqueous extract of Theobroma cacao on the histology of the ovary of female albino wistar rat. Twenty-four (24) adult wistar female rats weighting about 100- 160g were used for this research work and were divided into three (3) groups of eight (8) animals each. Group A; control, Group B; low dose and Group C; high dose with eight (8) animals in each group. Control group received vital feed; the low dose group was administered 240mgkg body weight of Theobroma cacao extract and the high dose group was administered 500mgkg body weight of the test substance. Extract was given daily by oral gavage method for twenty-one (21) days. Twenty-four hours after the last administration, all animals in each group were sacrificed under chloroform anesthesia. The ovaries were harvested, weighed and fixed in 10% buffered formalin for histological studies. Results showed that following administration of extract of Theoboma cacao at these doses, an insignificant decrease in organ weight was observed. Histological observation showed few follicles as well as loss of the substance of granulose cell this could possibly suggest decrease in production of sex steroids in the ovary.Keywords: Theobroma Cacao, Ovary, Histolog

Rapid modification of the insect elicitor N-linolenoyl-glutamate via a lipoxygenase-mediated mechanism on Nicotiana attenuata leaves

<p>Abstract</p> <p>Background</p> <p>Some plants distinguish mechanical wounding from herbivore attack by recognizing specific constituents of larval oral secretions (OS) which are introduced into plant wounds during feeding. Fatty acid-amino acid conjugates (FACs) are major constituents of <it>Manduca sexta </it>OS and strong elicitors of herbivore-induced defense responses in <it>Nicotiana attenuata </it>plants.</p> <p>Results</p> <p>The metabolism of one of the major FACs in <it>M. sexta </it>OS, <it>N</it>-linolenoyl-glutamic acid (18:3-Glu), was analyzed on <it>N. attenuata </it>wounded leaf surfaces. Between 50 to 70% of the 18:3-Glu in the OS or of synthetic 18:3-Glu were metabolized within 30 seconds of application to leaf wounds. This heat-labile process did not result in free α-linolenic acid (18:3) and glutamate but in the biogenesis of metabolites both more and less polar than 18:3-Glu. Identification of the major modified forms of this FAC showed that they corresponded to 13-hydroxy-18:3-Glu, 13-hydroperoxy-18:3-Glu and 13-oxo-13:2-Glu. The formation of these metabolites occurred on the wounded leaf surface and it was dependent on lipoxygenase (LOX) activity; plants silenced in the expression of <it>NaLOX2 </it>and <it>NaLOX3 </it>genes showed more than 50% reduced rates of 18:3-Glu conversion and accumulated smaller amounts of the oxygenated derivatives compared to wild-type plants. Similar to 18:3-Glu, 13-oxo-13:2-Glu activated the enhanced accumulation of jasmonic acid (JA) in <it>N. attenuata </it>leaves whereas 13-hydroxy-18:3-Glu did not. Moreover, compared to 18:3-Glu elicitation, 13-oxo-13:2-Glu induced the differential emission of two monoterpene volatiles (β-pinene and an unidentified monoterpene) in ir<it>lox2 </it>plants.</p> <p>Conclusions</p> <p>The metabolism of one of the major elicitors of herbivore-specific responses in <it>N. attenuata </it>plants, 18:3-Glu, results in the formation of oxidized forms of this FAC by a LOX-dependent mechanism. One of these derivatives, 13-oxo-13:2-Glu, is an active elicitor of JA biosynthesis and differential monoterpene emission.</p

Protective effects of Buchholzia coriacea seeds extract and fractions on blood glucose and hyperlipidemia in diabetic rats

Background: The Buchholzia coriacea seeds (Capparaceae) are used in Nigerian ethnomedicine for treatment of hyperglycemia. Our aim, therefore, is to evaluate antihyperglycemic and hypolipidemic effects of extract and fractions of Bulcholzia coriacea seeds.Methods: The cut, dried and pulverized seeds were extracted with a mixture of methanol-dichloromethane (1:1) which yielded the crude extract, MDE. The MDE was fractionated using bioactive guided procedure and yielded hexane fraction (HF), ethylacetate fraction (EF) and methanol fraction (MF). Alloxan-induced diabetes, normoglycemic test and oral glucose tolerance test (OGTT) were the antidiabetic models employed, while hypolipidemic study was performed using standard assay kits to determine the serum total cholesterol (TC) triglycerides (TG) and low density lipoproteins (LDL). Acute toxicity test of the extract was performed using Lorke’s method while qualitative and quantitative phytochemical analyses were also performed using standard procedures.Results: The results showed an oral median lethality dose (LD50) greater than 5000mg/kg. The extract and fractions showed significant antihyperglycemic effect comparable and in synergy to metformin, a standard agent. The extract (200mg/kg) showed the highest percentage blood glucose reduction (PBGR) of 52.89% while ethylacetate fraction (EF, 400mg/kg) showed PBGR of 50.84%. Also, the MDE and hexane fraction (HF) showed a significant reduction of TC, TG and LDL and related increase in HDL-C levels in diabetic treated rats.Conclusions: The extract and the fractions of Buchholzia coriacea seeds possess antihyperglycemic and antihyperlipidemic effects and showed same mechanism of action as metformin, thus providing scientific rationale for its folkloric use

Amputation‑Related Phantom Limb Pain in Nigeria: A Prospective Cohort Study

Background: Phantom limb pain (PLP) is a common and distressing complication of limb amputations. Literature on PLP in Nigeria and indeedAfrica is scant despite the high rate of amputations in published works. We sought to highlight the burden of PLP among Nigerian amputeesin order to improve awareness and care by health‑care providers. Patients and Methods: In this prospective cohort study, consecutive limb amputees were recruited and relevant data were collected by in‑person interview at 1 week postamputation and subsequently by telephone survey at 6 months and 12 months. The sociodemographic and clinical&nbsp;&nbsp; information of the amputees were recorded, as well as presence of PLP and the treatment offered by the attending physician. The Chi‑square test of statistical significance and multivariate analysis using binary logistic regression were used in the analysis, and the level of statistical significance was determined by P &lt; 0.05. Results: One hundred and fourteen consecutive limb amputations were carried out in 113 patients over a 1‑year period. The period prevalence of PLP was 63.6%, and of these, only 8.6% had this documented in their medical record. No predictor of PLP was identified in the cohort. Conclusion:&nbsp; PLP is highly prevalent among limb amputees in our cohort. We call for improved awareness and practice relating to PLP among&nbsp; health‑care providers and partners, considering the vast population of amputees in the region. Keywords: Africa, American Society of Anesthesiologists physical status grade, amputees, phantom limb pai