Sympathetic cooling of positrons to cryogenic temperatures for antihydrogen production

The positron, the antiparticle of the electron, predicted by Dirac in 1931 and discovered by Anderson in 1933, plays a key role in many scientific and everyday endeavours. Notably, the positron is a constituent of antihydrogen, the only long-lived neutral antimatter bound state that can currently be synthesized at low energy, presenting a prominent system for testing fundamental symmetries with high precision. Here, we report on the use of laser cooled Be+ ions to sympathetically cool a large and dense plasma of positrons to directly measured temperatures below 7 K in a Penning trap for antihydrogen synthesis. This will likely herald a significant increase in the amount of antihydrogen available for experimentation, thus facilitating further improvements in studies of fundamental symmetries

High-risk human papillomavirus (HPV) screening and detection in healthy patient saliva samples: a pilot study

<p>Abstract</p> <p>Background</p> <p>The human papillomaviruses (HPV) are a large family of non-enveloped DNA viruses, mainly associated with cervical cancers. Recent epidemiologic evidence has suggested that HPV may be an independent risk factor for oropharyngeal cancers. Evidence now suggests HPV may modulate the malignancy process in some tobacco- and alcohol-induced oropharynx tumors, but might also be the primary oncogenic factor for inducing carcinogenesis among some non-smokers. More evidence, however, is needed regarding oral HPV prevalence among healthy adults to estimate risk. The goal of this study was to perform an HPV screening of normal healthy adults to assess oral HPV prevalence.</p> <p>Methods</p> <p>Healthy adult patients at a US dental school were selected to participate in this pilot study. DNA was isolated from saliva samples and screened for high-risk HPV strains HPV16 and HPV18 and further processed using qPCR for quantification and to confirm analytical sensitivity and specificity.</p> <p>Results</p> <p>Chi-square analysis revealed the patient sample was representative of the general clinic population with respect to gender, race and age (<it>p </it>< 0.05). Four patient samples were found to harbor HPV16 DNA, representing 2.6% of the total (n = 151). Three of the four HPV16-positive samples were from patients under 65 years of age and all four were female and Hispanic (non-White). No samples tested positive for HPV18.</p> <p>Conclusions</p> <p>The successful recruitment and screening of healthy adult patients revealed HPV16, but not HPV18, was present in a small subset. These results provide new information about oral HPV status, which may help to contextualize results from other studies that demonstrate oral cancer rates have risen in the US among both females and minorities and in some geographic areas that are not solely explained by rates of tobacco and alcohol use. The results of this study may be of significant value to further our understanding of oral health and disease risk, as well as to help design future studies exploring the role of other factors that influence oral HPV exposure, as well as the short- and long-term consequences of oral HPV infection.</p

Laser cooling of antihydrogen atoms

The photon—the quantum excitation of the electromagnetic field—is massless but carries momentum. A photon can therefore exert a force on an object upon collision1. Slowing the translational motion of atoms and ions by application of such a force2,3, known as laser cooling, was first demonstrated 40 years ago4,5. It revolutionized atomic physics over the following decades6–8, and it is now a workhorse in many fields, including studies on quantum degenerate gases, quantum information, atomic clocks and tests of fundamental physics. However, this technique has not yet been applied to antimatter. Here we demonstrate laser cooling of antihydrogen9, the antimatter atom consisting of an antiproton and a positron. By exciting the 1S–2P transition in antihydrogen with pulsed, narrow-linewidth, Lyman-α laser radiation10,11, we Doppler-cool a sample of magnetically trapped antihydrogen. Although we apply laser cooling in only one dimension, the trap couples the longitudinal and transverse motions of the anti-atoms, leading to cooling in all three dimensions. We observe a reduction in the median transverse energy by more than an order of magnitude—with a substantial fraction of the anti-atoms attaining submicroelectronvolt transverse kinetic energies. We also report the observation of the laser-driven 1S–2S transition in samples of laser-cooled antihydrogen atoms. The observed spectral line is approximately four times narrower than that obtained without laser cooling. The demonstration of laser cooling and its immediate application has far-reaching implications for antimatter studies. A more localized, denser and colder sample of antihydrogen will drastically improve spectroscopic11–13 and gravitational14 studies of antihydrogen in ongoing experiments. Furthermore, the demonstrated ability to manipulate the motion of antimatter atoms by laser light will potentially provide ground-breaking opportunities for future experiments, such as anti-atomic fountains, anti-atom interferometry and the creation of antimatter molecules

The Dynamic of ICT and Smart Power: Implications for Managerial Practice

This chapter examines the concept of smart power and its interaction with innovations in information and communications technology (ICT) and management practice in contemporary organizational settings. Smart power is a composite of hard power (involving, for example, force, discipline, and direction) and soft power (including, by way of illustration, influencing, persuading and relationship building). Historically and conventionally, managerial practice has been cast having a propensity towards hard power yet in recent decades emergent approaches have witnessed the rise and increasing use of soft power. Importantly, the confluence of ‘hard’ and soft’ power produces ‘smart power’ which, interconnected with radical evolutions in ICT, produces a potentially potent amalgam and set of circumstances for organizations and managers. The chapter considers the above phenomena through an examination of three focal ICT areas: social media, data analytics, and mobile computing each of which challenges longstanding and conventional organizational operating modes and mindsets. Methodologically, the chapter collates, analyses and employs a range of sources including interviews, case studies and industry reports. The resultant analysis and discussion identify ways in which smart power interacts with ICT and the implications of this for management and organizations. In particular, it identifies shifts in established patterns of power, control and authority, as organizations seek to address their needs using these technologies. Finally, the chapter indicates potential negative and unintended effects of ICT in order to provide a deeper understanding of ICT and smart power

Perfil fonológico de crianças com baixa visão de 6 a 9 anos de idade em uma instituição para cegos na cidade de Salvador - BA

Resumo: OBJETIVO: descrever o perfil fonológico de crianças com baixa visão de 6 a 9 anos de idade, que não apresentem outra patologia associada, e assim, analisar se ocorre diferenças significantes no desenvolvimento fonológico dessas crianças em comparação com o desenvolvimento fonológico de crianças com visão normal. MÉTODOS: estudo descritivo, observacional, transversal e qualitativo. Foram analisadas 20 crianças com idades entre 6 e 9 anos, cadastradas em uma instituição para cegos na cidade de Salvador-Ba, com baixa visão e que não apresentava outra patologia associada. Para testagem do sistema fonológico utilizou-se o Protocolo de Avaliação Fonológica Infantil que consiste na nomeação de 43 figuras balanceadas foneticamente. A nomeação foi registrada em vídeo. As informações observadas e registradas durante o teste foram organizadas para análise por meio do emparelhamento de acordo a faixa etária. RESULTADOS: após análise detalhada das amostras de fala registradas em vídeo, os resultados foram organizados por idade em quadros, descrevendo quais fonemas foram produzidos em cada segmento do Português Brasileiro avaliado e os processos fonológicos utilizados. CONCLUSÃO: o desenvolvimento fonológico das crianças com baixa visão ocorre por um processo mais lento e tardio quando comparado ao desenvolvimento fonológico típico de crianças com visão normal