Indoor secondhand tobacco smoke emission levels in six Lebanese cities

Background: To date, Lebanon has failed to enact comprehensive clean indoor air laws despite ratification of the Framework Convention on Tobacco Control (FCTC), which calls for the protection of non-smokers from exposure to secondhand tobacco smoke (SHS). Complicating the problem of SHS exposure in Lebanon is the widespread use of the tobacco water-pipe. While most research on SHS has involved cigarette smoking as a source of emissions, other sources, including tobacco water-pipes, may be an important contributor. Methods: $PM_{2.5}$ concentrations $(\mu g/m^3)$ were measured in a sample of 28 public venues located in six major Lebanese cities. Active smoker density (number of smokers$/100 m^3$) was calculated for both water-pipe and cigarette smokers. Venues were then categorised as having higher density of water-pipe smokers or higher density of cigarette smokers, and resultant emission levels were compared between the two groups. Results: Cigarette and water-pipe smoking was observed in 14 venues, while cigarette smoking only and water-pipe smoking only were found in 12 venues and one venue, respectively. Among all smoking-permitted venues, the mean $PM_{2.5}$ concentration was $342 \mu g/m^3$. Venues with a higher density of water-pipe smokers $(n =14)$ showed a similar median $PM_{2.5}$ concentration $349 \mu g/m^3$ compared with venues with a higher density of cigarette smokers $(n =13; 241 \mu g/m^3; p=0.159)$. The mean $PM_{2.5}$ concentration in the single venue with a voluntary smoke-free policy was $6 \mu g/m^3$. Conclusions: Despite ratification of the FCTC in 2005, both cigarette and water-pipe smoking are commonly practised in enclosed public places throughout Lebanon, leading to unsafe levels of indoor particulate pollution. Smoke-free policies are needed in Lebanon to protect the public's health, and should apply to all forms of tobacco smoking

An Active Role for the Ribosome in Determining the Fate of Oxidized mRNA

Chemical damage to RNA affects its functional properties and thus may pose a significant hurdle to the translational apparatus; however, the effects of damaged mRNA on the speed and accuracy of the decoding process and their interplay with quality-control processes are not known. Here, we systematically explore the effects of oxidative damage on the decoding process using a well-defined bacterial in vitro translation system. We find that the oxidative lesion 8-oxoguanosine (8-oxoG) reduces the rate of peptide-bond formation by more than three orders of magnitude independent of its position within the codon. Interestingly, 8-oxoG had little effect on the fidelity of the selection process, suggesting that the modification stalls the translational machinery. Consistent with these findings, 8-oxoG mRNAs were observed to accumulate and associate with polyribosomes in yeast strains in which no-go decay is compromised. Our data provide compelling evidence that mRNA-surveillance mechanisms have evolved to cope with damaged mRNA

The elevated Curie temperature and half-metallicity in the ferromagnetic semiconductor Lax_{x}Eu1−x_{1-x}O

Here we study the effect of La doping in EuO thin films using SQUID magnetometry, muon spin rotation ($\mu$SR), polarized neutron reflectivity (PNR), and density functional theory (DFT). The $\mu$SR data shows that the La$_{0.15}$Eu$_{0.85}$O is homogeneously magnetically ordered up to its elevated $T_{\rm C}$. It is concluded that bound magnetic polaron behavior does not explain the increase in $T_{\rm C}$ and an RKKY-like interaction is consistent with the $\mu$SR data. The estimation of the magnetic moment by DFT simulations concurs with the results obtained by PNR, showing a reduction of the magnetic moment per La$_{x}$Eu$_{1-x}$O for increasing lanthanum doping. This reduction of the magnetic moment is explained by the reduction of the number of Eu-4$f$ electrons present in all the magnetic interactions in EuO films. Finally, we show that an upwards shift of the Fermi energy with La or Gd doping gives rise to half-metallicity for doping levels as high as 3.2 %.Comment: 7 pages, 11 figure

Non-Hodgkin's lymphoma in a woman with adult-onset Still's disease: a case report

INTRODUCTION: Adult onset Still's disease is a chronic multisystemic inflammatory disorder characterized by high spiking fever, polyarthralgia and rash. Lymphadenopathy is a prominent feature of adult onset Still's disease and is seen in about 65% of patients. Searching the medical literature using the MEDLINE database from January 1966 through November 2007 we could only find two reported cases of adult onset Still's disease that had progressed to lymphoma. CASE PRESENTATION: We describe a woman who was diagnosed with adult onset Still's disease and developed lymphoma 10 months after the onset of her symptoms. She initially presented with fever and arthritis of the knees, ankles and shoulders, along with a nonpruritic skin rash, myalgia and weight loss. On physical examination she was found to have several enlarged anterior cervical lymph nodes and left posterior auricular lymph nodes all of which were non-tender, immobile and rubbery. Excisional biopsy of the cervical lymph nodes was negative for malignancy. Bone marrow biopsy was also negative for malignancy. She was treated with prednisone. She remained in good health until she presented 10 months later with low back pain, dyspnea and weight loss. Work up revealed malignant lymphoma. She was treated with chemotherapy and was doing well until she presented with abdominal pain. Work up revealed a cirrhotic liver and ascites. She then passed away from hepatorenal syndrome 13 years after the diagnosis of lymphoma. To our knowledge, this is the third reported case of such an occurrence. CONCLUSION: Although the association between adult onset Still's disease and lymphoma has been rarely reported, careful screening for this malignancy in patients suspected to have adult onset Still's disease is warranted

Phylogenetic relationships of the genus Sibynophis (Serpentes: Colubroidea)

Os resultados apresentados correspondem à primeira análise molecular feita acerca das afinidades filogenéticas do gênero Sibynophis, um colubróideo de origem asiática. Sibynophis aparece como sendo o grupo-irmão do gênero Neotropical Scaphiodontophis. Embora Liophidium esteja por vezes associado a estes dois gêneros, a sua relação é apenas distante. Os caracteres morfológicos compartilhados entre Liophidium, Sibynophis e Scaphiodontophis correspondem a homoplasias que refletem provavelmente os hábitos alimentares especializados semelhantes, presentes nos três gêneros em questão. A tradicional subfamília Sibynophiinae é elevada ao nível de família, enquanto que Scaphiodontophiinae passa para sua sinonímia.We present the results of the first molecular analysis of the phylogenetic affinities of the Asian colubroid genus Sibynophis. We recovered a sister-group relationship between Sibynophis and the New World Scaphiodontophis. Although Liophidium sometimes is associated with these genera, the relationship is distant. Morphological characters that Liophidium shares with Sibynophis and Scaphiodontophis are resolved as homoplasies that probably reflect the similarities of their specialized feeding habits. The traditional subfamily Sibynophiinae is elevated to the family-level, and Scaphiodontophiinae is placed in its synonymy

Proximity-Induced Odd-Frequency Superconductivity in a Topological Insulator

At an interface between a topological insulator (TI) and a conventional superconductor (SC), superconductivity has been predicted to change dramatically and exhibit novel correlations. In particular, the induced superconductivity by an $s$-wave SC in a TI can develop an order parameter with a $p$-wave component. Here we present experimental evidence for an unexpected proximity-induced novel superconducting state in a thin layer of the prototypical TI, Bi$_2$Se$_3$, proximity coupled to Nb. From depth-resolved magnetic field measurements below the superconducting transition temperature of Nb, we observe a local enhancement of the magnetic field in Bi$_2$Se$_3$ that exceeds the externally applied field, thus supporting the existence of an intrinsic paramagnetic Meissner effect arising from an odd-frequency superconducting state. Our experimental results are complemented by theoretical calculations supporting the appearance of such a component at the interface which extends into the TI. This state is topologically distinct from the conventional Bardeen-Cooper-Schrieffer state it originates from. To the best of our knowledge, these findings present a first observation of bulk odd-frequency superconductivity in a TI. We thus reaffirm the potential of the TI-SC interface as a versatile platform to produce novel superconducting states.Comment: Accepted version for publication in Physical Review Letter