Evaluation of the potential for virus dispersal during hand drying: a comparison of three methods

Aims To use a MS2 bacteriophage model to compare three hand-drying methods, paper towels (PT), a warm air dryer (WAD) and a jet air dryer (JAD), for their potential to disperse viruses and contaminate the immediate environment during use. Methods and Results Participants washed their gloved hands with a suspension of MS2 bacteriophage and hands were dried with one of the three hand-drying devices. The quantity of MS2 present in the areas around each device was determined using a plaque assay. Samples were collected from plates containing the indicator strain, placed at varying heights and distances and also from the air. Over a height range of 0.15-1.65 m, the JAD dispersed an average of >60 and >1300-fold more plaque-forming units (pfu) compared to the WAD and PT (P <0.0001), respectively. The JAD dispersed an average of >20 and >190-fold more pfu in total compared to WAD and PT at all distances tested up to 3 m (P <0.01), respectively. Air samples collected around each device 15 minutes after use indicated that the JAD dispersed an average of >50 and >100-fold more pfu compared to the WAD and PT (P <0.001), respectively. Conclusions Use of the JAD lead to significantly greater and further dispersal of MS2 bacteriophage from artificially contaminated hands when compared to the WAD and PT. Significance and Impact of Study The choice of hand drying device should be considered carefully in areas where infection prevention concerns are paramount, such as healthcare settings and the food industry.

Comparison of virus dispersal and aerosolization by different hand-drying devices

Background World Health Organization and EU hand hygiene guidelines state that if electric hand dryers are used, they should not aerosolize pathogens. Previous studies have investigated the dispersal by different hand-drying devices of chemical indicators, fungi and bacteria on the hands. This study assessed the aerosolization and dispersal of virus on the hands to determine any differences between hand-drying devices in their potential to contaminate other occupants of public washrooms and the washroom environment. Methods A suspension of MS2, an Escherichia coli bacteriophage virus, was used to artificially contaminate the hands of participants prior to using three different hand-drying devices: jet air dryer, warm air dryer, paper towel dispenser. Virus was detected by plaque formation on agar plates layered with the host bacterium. Vertical dispersal of virus was assessed at a fixed distance (0.4 m) and over a range of different heights (0.0 – 1.8 m) from the floor. Horizontal dispersal was assessed at different distances of up to three metres from the hand-drying devices. Virus aerosolization and dispersal was also assessed at different times up to 15 minutes after use by means of air sampling at two distances (0.1 and 1.0 m) and at a distance behind and offset from each of the hand-drying devices. Results Over a range of heights, the jet air dryer was shown to produce over 60 times greater vertical dispersal of virus from the hands than a warm air dryer and over 1300 times greater than paper towels; the maximum being detected between 0.6 and 1.2 metres from the floor. Horizontal dispersal of virus by the jet air dryer was over 20 times greater than a warm air dryer and over 190 times greater than paper towels; virus being detected at distances of up to three metres. Air sampling at three different positions from the hand-drying devices 15 minutes after use showed that the jet air dryer produced over 50-times greater viral contamination of the air than a warm air dryer and over 110-times greater than paper towels. Conclusions Due to their high air speed, jet air dryers aerosolize and disperse more virus over a range of heights, greater distances, and for longer times than other hand drying devices. If hands are inadequately washed, they have a greater potential to contaminate other occupants of a public washroom and the washroom environment. Main messages: Jet air dryers with claimed air speeds of over 600 kph have a greater potential than warm air dryers or paper towels to aerosolize and disperse viruses on the hands of users. The choice of hand-drying device should be carefully considered. Jet air dryers may increase the risk of transmission of human viruses, such as norovirus, particularly if hand washing is inadequate.

Reliable and Fast Hand-Offs in Low-Power Wireless Networks

Hand-off (or hand-over), the process where mobile nodes select the best access point available to transfer data, has been well studied in wireless networks. The performance of a hand-off process depends on the specific characteristics of the wireless links. In the case of low-power wireless networks, hand-off decisions must be carefully taken by considering the unique properties of inexpensive low-power radios. This paper addresses the design, implementation and evaluation of smart-HOP, a hand-off mechanism tailored for low-power wireless networks. This work has three main contributions. First, it formulates the hard hand-off process for low-power networks (such as typical wireless sensor networks - WSNs) with a probabilistic model, to investigate the impact of the most relevant channel parameters through an analytical approach. Second, it confirms the probabilistic model through simulation and further elaborates on the impact of several hand-off parameters. Third, it fine-tunes the most relevant hand-off parameters via an extended set of experiments, in a realistic experimental scenario. The evaluation shows that smart-HOP performs well in the transitional region while achieving more than 98 percent relative delivery ratio and hand-off delays in the order of a few tens of a milliseconds.

Hand Involvement in Ollier Disease and Maffucci Syndrome: a Case Series

Ollier Disease and Maffucci Syndrome are two rare diseases that can cause tumors in several organs, having a special predilection for the hand. However, there have been very few reports in the literature focusing on hand manifestations of these diseases. We report the cases of three female patients: one with Ollier Disease, and two other with Maffucci Syndrome. All patients had hand involvement as their initial primary complaint. The Ollier Disease patient developed chondrosarcomas of two digits and had to have these fingers amputated. One of the Maffucci patients died one year after presentation from a brain glioblastoma. These cases emphasize the importance of early diagnosis of Ollier Disease and Maffucci Syndrome, as these two conditions are associated not only to crippling hand deformity, but also to a significant risk of chondrosarcoma, and other malignant tumors.

Rapps Sistema de recomendação de apps de produtividade para Android

Nos últimos anos, a nossa sociedade sofreu alterações significativas ao nível tecnológico que têm vindo a modificar o quotidiano do cidadão e transportaram para a palma da mão um conjunto significativo de tarefas até há poucos anos impensáveis. Atualmente, torna-se possível realizar as mais simples tarefas como, a título de exemplo, efetuar um cálculo matemático, tirar fotografias ou registar numa agenda um compromisso, ou tarefas mais complexas, como por exemplo, escrever ou editar um documento, trabalhar numa folha de cálculo ou enviar um e-mail com um anexo, isto tudo com o recurso a um simples dispositivo móvel, conhecido como smartphone ou tablet. Apesar de existirem diversos tipos de apps que seriam um bom auxílio para o aumento da produtividade dos utilizadores de dispositivos móveis Android, nem todos têm conhecimento das mesmas, pelo que é importante que os utilizadores tenham conhecimentos das vantagens da utilização destes recursos e de tudo o que podem realizar com os seus dispositivos com o objetivo de aumentar a sua produtividade profissional ou pessoal. O presente estudo pretende contribuir para uma análise sobre a potencial utilização das novas tecnologias, mais propriamente estudando e recomendando apps de produtividade. Com este intuito foi criada uma app de recomendação de aplicações de produtividade com recurso a um método de sistemas de recomendação. São apresentados os resultados e as conclusões, com recurso a opiniões de potenciais utilizadores.

Why did Swiss citizens refuse a comprehensive second-hand smoke ban?

The ill effects of second-hand smoke are now well documented. To protect the population from exposure to tobacco smoke, comprehensive smoking bans are necessary as expressed in the WHO Framework Convention on Tobacco Control and its guidelines. Switzerland has only a partial smoking ban full of exceptions which has been in effect since 2010, which reproduces the so-called Spanish model. In September 2012, the Swiss citizens refused a proposal for a more comprehensive ban. This case study examines the reasons behind this rejection and draws some lessons that can be learnt from it.

« Recueil de matières de finance pour l'instruction du Roy, par M. D. C[HANDÉ]. Tome Ier. — 1722 ».

Contient : Abrégé chronologique des monnoies ; Dissertation sur la livre de compte ; Ferme du tabac ; Francs-fiefs ; Amortissemens ; Huitième et sixième denier ecclésiastique ; Insinuations laïques ; Controlle des actes des notaires ; Petits scels ; Cartes à jouer

Joyce Chapman, Palm Springs, California, 1998

Joyce Chapman, daughter of Grant and Zella Chapman; granddaughter of Frank M. Chapman, Palm Springs, California, 1998. Copyright Image Makers, Palm Springs, CA.

Joyce Chapman outside the Chapman Building, Palm Springs, California, 1960

Joyce Chapman outside the Chapman Building, Palm Springs, California, 1960.

The Ontario and St. Lawrence Steamboat Company's hand-book for travelers to Niagara Falls, Montreal and Quebec, and through Lake Champlain to Saratoga Springs.

"Illustrated with maps, and numerous engravings from original sketches."

Joyce Chapman, Palm Springs, California, 1998

Joyce Chapman, daughter of Grant and Zella Chapman; granddaughter of Frank M. Chapman, Palm Springs, California, 1998.

Joyce Chapman, Palm Springs, California, 1998

Joyce Chapman, Palm Springs, California, 1998. She is the granddaughter of C. C. Chapman's brother, Frank M. Chapman.