694 research outputs found

    Non-monotoic fluctuation-induced interactions between dielectric slabs carrying charge disorder

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    We investigate the effect of monopolar charge disorder on the classical fluctuation-induced interactions between randomly charged net-neutral dielectric slabs and discuss various generalizations of recent results (A. Naji et al., Phys. Rev. Lett. 104, 060601 (2010)) to highly inhomogeneous dielectric systems with and without statistical disorder correlations. We shall focus on the specific case of two generally dissimilar plane-parallel slabs, which interact across vacuum or an arbitrary intervening dielectric medium. Monopolar charge disorder is considered to be present on the bounding surfaces and/or in the bulk of the slabs, may be in general quenched or annealed and may possess a finite lateral correlation length reflecting possible `patchiness' of the random charge distribution. In the case of quenched disorder, the bulk disorder is shown to give rise to an additive long-range contribution to the total force, which decays as the inverse distance between the slabs and may be attractive or repulsive depending on the dielectric constants of the slabs. We show that in the case of two dissimilar slabs the net effect due to the interplay between the disorder-induced and the pure van der Waals interactions can lead to a variety of unusual non-monotonic interaction profiles between the dielectric slabs. In particular, when the intervening medium has a larger dielectric constant than the two slabs, we find that the net interaction can become repulsive and exhibit a potential barrier, while the underlying van der Waals force is attractive. On the contrary, when the intervening medium has a dielectric constant in between that of the two slabs, the net interaction can become attractive and exhibit a free energy minimum, while the pure van der Waals force is repulsive. Therefore, the charge disorder, if present, can drastically alter the effective interaction between net-neutral objects.Comment: 13 pages, 8 figure

    Novel Smartphone Interventions Improve Cognitive Flexibility and Obsessive-Compulsive Disorder Symptoms in Individuals with Contamination Fears.

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    One type of obsessive-compulsive disorder (OCD) is characterized by contamination fears and compulsive cleansing. Few effective treatments are available for this debilitating condition. Compulsive symptoms, such as excessive washing, are believed to be mediated by cognitive inflexibility-arguably the most striking cognitive impairment in OCD. In this study, we investigated the effects of two novel smartphone interventions on cognitive flexibility and OCD symptoms in healthy individuals with OCD-like contamination fears. In the first intervention, participants watched a brief video recording of themselves engaging in handwashing on a smartphone, four times a day, for a total of one week (N = 31). The second intervention was similar except that participants watched themselves repeatedly touching a disgust-inducing object (N = 31). In a third (control) "intervention", participants watched themselves performing sequential hand movements (N = 31). As hypothesized, the two smartphone interventions, unlike the control, improved cognitive flexibility; as assessed on the Intradimensional-Extradimensional Set Shifting task (a sensitive marker of cognitive flexibility). The two interventions, unlike the control, also improved OCD symptoms (measured with the Obsessive-Compulsive Inventory-Revised and Yale-Brown Obsessive-Compulsive Scale). Finally, we found high levels of adherence to the interventions. These findings have significant clinical implications for OCD

    BETWEEN THE BIOACTIVE EXTRACTS OF EDIBLE MUSHROOMS AND PHARMACOLOGICALLY IMPORTANT NANOPARTICLES: NEED FOR THE INVESTIGATION OF A SYNERGISTIC COMBINATION - A MINI REVIEW

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    ABSTRACTThe pharmacological potential of bioactive compounds extracted from mushrooms has been studied to a reasonable level. In the same vein, thebioactivity of nanoparticles has also been investigated and reported to be of potential pharmacological benefit. No doubt, there is a reasonableamount of claims regarding the vast activity of the mushroom extracts and nanoparticles on the tested cell lines and microorganisms. In this paper,a review of the recent application of bioactive compounds extracted from two edible mushrooms (Coprinus comatus and Lactarius deliciosus), aswell as some of the recently reported studies on some nanoparticles of pharmacological potentials, was carried out. In order to check for synergy inthe bioactivity of the mushroom extracts when co-administered with nanoparticles, an investigation on the synergistic application of the materialsthrough the encapsulation of the bioactive extracts from the mushroom onto the nanoparticle was proposed. The supposed synergy in the activity ofthe extract-nanoparticle complex could hold the key to improved activity of nutraceuticals against resistant microorganisms and tumor cells.Keywords: Coprinus comatus, Lactarius deliciosus, Nanoparticles, Synergy, Bioactive extracts

    Simulation and analysis for harvesting Dioscorea hispida tubers

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    This study discussed an analysis and simulation of fixture stand structure that will use for data collection of force required for harvesting the tubers of Dioscorea hispida. The tubers were surrounded by roots which were well gripped to the soil which made harvesting process difficult. Therefore, a new tool fixture equipped with digital force gauge device to gripped stem dioscorea hispida is required. Imada digital force measurement gauges are state-of-the-art, instruments capable of the highly accurate measurements required in quality testing to determine the strength or functionality of a part or product. The information from the experiments is used to model and simulate the tool in Computer Aided Design (CAD) environment. The solid modelling software Solidworks was used for the design, modelling and simulation of the equipment and the finite element analysis to determine the stress affected on various fixture designs

    Limnological parameters affecting monthly abundance of Chironomid larvae in a fish pond and their role in the diet of catfish, Clarias batrachus

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    Six months-long experiment was carried out in a fish pond at Bangladesh Agricultural University (BAU), Mymensingh from September 2008-February 2009 to evaluate the limnological parameters affecting monthly abundance of Chironomid larvae and their role in the diet of catfish, Clarias batrachus. The water-quality and soil parameters were monitored and found to be within suitable range for freshwater aquaculture. The composition of the benthic macro-invertebrates at the bottom indicated that Chironomidae was most dominant group in this pond. The body-weight percentage of the organisms showed that Chironomids and Oligochaetes were major two groups. The quantitative and qualitative studies of Chironomid larvae indicated that there was monthly variation in the abundance of Chironomids where Chironomus was most dominant. The highest (3585.19 m-2) and the lowest (548.15 m-2) abundance of Chironomids in 3 samples were recorded in the month of January 2009 and October 2008, respectively. Gut content analysis suggested that Chironomids was dominant food item in the diet of Clarias batrachus. The maximum 768 and minimum 25 occurrences were recorded in the months of December and October 2008, respectively in 5 fishes sampled from the experimental pond. The electivity indices suggested a shifting to Chironomid larvae from negative selection to positive selection in different months

    Perceptions of UK Community Pharmacists on Current Consultation Skills and Motivational Interviewing as a Consultation Approach: A Qualitative Study

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    Community pharmacists' roles in the UK are evolving; pharmacists currently deliver a wider range of clinical services with more patient-focused care. The objectives of this study were (i) to investigate UK community pharmacists' views on their current communication skills in pharmacist-patient facing consultations, and (ii) to explore the perceptions of UK community pharmacists towards the application of motivational interviewing (MI) in a pharmacy consultation. In-depth qualitative face-to-face, semi-structured interviews with ten practicing community pharmacists were carried out, ranging from 30-60 minutes in length. The interviews were audio recorded, transcribed verbatim and thematic analysis was employed. Four themes emerged from the data: (1) the fight for time; (2) wrestling with consultation styles; (3) a personal communication evolution; and (4) unfamiliar but engaging motivational interviewing. These themes demonstrated the juxtaposition between the desire for patient-centred care and the pressures of managing broader dispensing work. Participants were critical of academic and continuous professional learning (CPD) training in communication skills and there was a strong recognition of the potential role of MI in promoting patient autonomy and outcomes. Participants recognized a few elements of MI techniques in their current consultations, but welcomed further training on behavioral change for effective consultations, expressing a desire for practical MI-specific training. Face-to-face CPD of consultation skills is needed to avoid the feeling of isolation among UK practicing pharmacists and rigidity in consultation delivery. Support for community pharmacists from other pharmacy staff could relieve current pressures and allow pharmacists time to develop and acquire effective skills for patient facing roles. Behavioural change consultation skills training for pharmacists could be an effective strategy to address these current challenges

    Isolation, characterisation and in vitro evaluation of bacteriocins-producing lactiv acid bacteria from fermented products of Northern Borneo for their beneficial roles in food industry

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    In this study, lactic acid bacteria (LAB) isolated from traditional fermented foods namely coco bean, fermented cabbage, salted vegetable, tempeh, tempoyak, tapai ubi and tapai nasi were screened for production of bacteriocin. Characterisation and in vitro evaluation of them were carried out to assess their potential use in food industry. Towards these objectives, the inhibitory spectra of the isolates against Listeria monocytogenes ATCC13932, resistance to phenol, amylolytic and proteolytic activities, ability to produce acid and coagulate milk, antibiotic susceptibility and tolerance in the presence of various concentration of NaCl and at different temperatures were evaluated. Two out of 15 LAB strains were able to inhibit the growth of food-borne pathogen, L. monocytogenes ATCC 13932 and produce bacteriocin-like inhibitory substances. The strains were identified as Pediococcus acidilactici TN1 (from tapai nasi) and Lactobacillus farciminis TY1 (from tempoyak). Biochemical and physiological tests demonstrated that, both strains were able to grow at wide range of NaCl concentrations (0.5 - 5.0 %, w/v) and temperatures (28 - 70 ˚C), and capable to degrade protein. They lowered the pH level and coagulate milk after 24 h of incubation. Both strains showed intrinsic mechanisms of antibiotic resistance towards streptomycin, norfloxacin, erythromycin, amikacin and nalidixic acid. They also were able to grow in 0.3% (w/v) of bile salts and tolerate up to 0.5% (w/v) phenol. The findings from this study revealed the presence of LAB strains in fermented foods of Northern Borneo which have an antimicrobial activity towards the food-borne pathogen. Even though this study had generated extensive information to validate Pediococcus acidilactici TN1 and Lactobacillus farciminis TY1 as potential probiotic strains for application in the food industry, the study is by no means comprehensive nor complete. More laboratory, particularly in vivo studies, are needed before this product could be accepted by the food industry and most importantly to explore its novel health promoting functions as well as its colonization behaviour in the gut
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