833 research outputs found

    Using social networking sites for communicable disease control: innovative contact tracing or breach of confidentiality?

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    Social media applications such as Twitter, YouTube and Facebook have attained huge popularity, with more than three billion people and organizations predicted to have a social networking account by 2015. Social media offers a rapid avenue of communication with the public and has potential benefits for communicable disease control and surveillance. However, its application in everyday public health practice raises a number of important issues around confidentiality and autonomy. We report here a case from local level health protection where the friend of an individual with meningococcal septicaemia used a social networking site to notify potential contacts

    Quantum Dot in 2D Topological Insulator: The Two-channel Kondo Fixed Point

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    In this work, a quantum dot couples to two helical edge states of a 2D topological insulator through weak tunnelings is studied. We show that if the electron interactions on the edge states are repulsive, with Luttinger liquid parameter K<1 K < 1 , the system flows to a stable two-channel fixed point at low temperatures. This is in contrast to the case of a quantum dot couples to two Luttinger liquid leads. In the latter case, a strong electron-electron repulsion is needed, with K<1/2 K<1/2 , to reach the two-channel fixed point. This two-channel fixed point is described by a boundary Sine-Gordon Hamiltonian with a KK dependent boundary term. The impurity entropy at zero temperature is shown to be ln2K \ln\sqrt{2K} . The impurity specific heat is CT2K2C \propto T^{\frac{2}{K}-2} when 2/3<K<1 2/3 < K < 1 , and CT C \propto T when K<2/3 K<2/3. We also show that the linear conductance across the two helical edges has non-trivial temperature dependence as a result of the renormalization group flow.Comment: 4+\epsilon page

    Diphtheria anti-toxoid antibody levels among pre-clinical students and staff in an institute of higher learning in Malaysia: are they protected?

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    Introduction: Little is known about the sero-prevalence of diphtheria anti-toxoid antibody levels among medical students in Malaysia. They too, just like other health care workers (HCWs) are at risk of contracting and transmitting diphtheria. Fortunately, this can be prevented by giving a specific vaccine: the diphtheria, tetanus and pertussis (DTP) vaccine. Nonetheless, data from local or regional surveys are needed before any decision is made by the respective authorities. General objective: We studied the epidemiology of diphtheria anti-toxoid antibody levels and vaccination history amongst medical students and staff in Faculty of Medicine and Health Sciences, Universiti Putra Malaysia. Specific objectives: We determined the level of diphtheria anti-toxoid antibodies amongst pre-clinical students and staff. Methodology: A total of 152 sera were collected from subjects aged 19 to 63, and diphtheria anti-toxoid levels were measured by an enzyme-linked immunosorbent assay. Results: One hundred and fifty-two (94.4%) blood samples out of 161 participants were successfully withdrawn, which comprised 105 (69.1%) and 47 (30.9%) medical students and staff, respectively. A total of 77.6% and the other 22.4% of the subjects had full and basic protection, respectively. Higher levels were predominant amongst males and they were 1.3 times more protected than females in 20-29 year-old group (85.1% vs 66.2%; odd ratios 1.25 [95% CI 1.03-1.50]; P=0.03). No significant difference in the levels of immunity among subjects for ethnicity and academic position (P>0.05). Recommendations: Level of full protection against diphtheria toxin should be clearly defined by broad population based studies using several comparable detection methods. Medical students and staff with basic protection should be closely monitored or should be given a booster dose for those who are at high risk of acquiring the disease. Thus, a standard degree of coverage should be clearly determined for health workers to prevent a potential outbreak. Conclusion: Students and staff possess immunity towards diptheria toxin however the level of full protective antibody is yet to be determined in future

    MicroRNA 302a is a novel modulator of cholesterol homeostasis and atherosclerosis

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    © 2014 American Heart Association, Inc. OBJECTIVE - : Macrophage foam cell formation is a key feature of atherosclerosis. Recent studies have shown that specific microRNAs (miRs) are regulated in modified low-density lipoprotein-treated macrophages, which can affect the cellular cholesterol homeostasis. Undertaking a genome-wide screen of miRs regulated in primary macrophages by modified low-density lipoprotein, miR-302a emerged as a potential candidate that may play a key role in macrophage cholesterol homeostasis. APPROACH AND RESULTS - : The objective of this study was to assess the involvement of miR-302a in macrophage lipid homeostasis and if it can influence circulating lipid levels and atherosclerotic development when it is inhibited in a murine atherosclerosis model. We found that transfection of primary macrophages with either miR-302a or anti-miR-302a regulated the expression of ATP-binding cassette (ABC) transporter ABCA1 mRNA and protein. Luciferase reporter assays showed that miR-302a repressed the 3′ untranslated regions (UTR) activity of mouse Abca1 by 48% and human ABCA1 by 45%. In addition, transfection of murine macrophages with miR-302a attenuated cholesterol efflux to apolipoprotein A-1 (apoA-1) by 38%. Long-term in vivo administration of anti-miR-302a to mice with low-density lipoprotein receptor deficiency (Ldlr) fed an atherogenic diet led to an increase in ABCA1 in the liver and aorta as well as an increase in circulating plasma high-density lipoprotein levels by 35% compared with that of control mice. The anti-miR-302a-treated mice also displayed reduced atherosclerotic plaque size by ≈25% and a more stable plaque morphology with reduced signs of inflammation. CONCLUSIONS - : These studies identify miR-302a as a novel modulator of cholesterol efflux and a potential therapeutic target for suppressing atherosclerosis

    Study of 5.8 GHz Band-Stop Frequency Selective Surface (FSS)

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    This paper presents the study of 5.8 GHz frequency selective surface (FSS) acts as a band stop to eliminate unwanted radiation signal at 5.8GHz. The FSS was designed using computer simulation technology (CST) Microwave Studio software. The paper shows the comparison of square loop, octagon loop and hexagon loop of Band stop FSS (BSFSS) performance at 5.8 GHz. Besides, the BSFSS design using four different type of dielectric substrate such as FR-4, TLY-5, Roger RT5870 and Roger RT5880 were compared. The results obviously show that the Rogers RY5880 has the attenuation -44.72 dB.&nbsp; The fabricated FSS were measured by using free space technique with two horn antennas connected to performance network analyzer (PNA). The measured and simulated results were compared. The results show that the square loop FSS structure have the better attenuation -26.76 dB (simulated) and -38.34 dB (measured) at 5.8 GHz

    Typing of Ralstonia solanacearum isolated from tomato by antibiotic susceptibility, plasmid profiling and PCR-based techniques of RAPD and ERIC

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    The epidemiological characteristics of Ralstonia solanacearum isolated from tomato plants in Sarawak and Selangor were studied. The epidemiological analysis of the strains was carried out through antibiotic resistant pattern, plasmid profiles, randomly amplified polymorphic DNA (RAPD) and enterobacterial repetitive intergenic consensus (ERIC) methods. Six strains were susceptible to all antibiotics tested, whereas the 10 strains that were resistant to one or more antibiotics were grouped into six antibiotic resistance patterns. Small single plasmid of 7.2 Mda and 9.2 Mda were detected among the nine plasmid containing strains, enabling them to be grouped into only two plasmid patterns. In the polymerase chain reaction, based methods using RAPD and ERIC, two strains were untypable by RAPD, whereas all were typable by ERIC. In this study, a wide diversity of R. solanacearum strains was examined. ERIC analysis demonstrated the clonal relationship between isolates from tomato plants in Sarawak and Selangor. The existence of similar R. solanacearum strains in tomato plants from two very distant locations should be considered if tomato strain fingerprint results were to be used to help trace the vehicles for transmission
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