Frequency and time standards based on stored ions

The method of ion storage provides a basis for excellent time and frequency standards. This is due to the ability to confine ions for long periods of time without the usual perturbations associated with confinement (e.g., wall shifts). In addition, Doppler effects can be greatly suppressed. The use of stored ions for microwave frequency standards and the future possibilities for an optical frequency standard based on stored ions are addressed

Helicopter gust response characteristics including unsteady aerodynamic stall effects

The results of an analytical study to evaluate the general response characteristics of a helicopter subjected to various types of discrete gust encounters are presented. The analysis employed was a nonlinear coupled, multi-blade rotorfuselage analysis including the effects of blade flexibility and unsteady aerodynamic stall. Only the controls-fixed response of the basic aircraft without any aircraft stability augmentation was considered. A discussion of the basic differences between gust sensitivity of fixed and rotary wing aircraft is presented. The effects of several rotor configuration and aircraft operating parameters on initial gust-induced load factor and blade vibratory stress and pushrod loads are discussed

Frontiers of parasitology research in the People's Republic of China : infection, diagnosis, protection and surveillance

ABSTRACT: Control and eventual elimination of human parasitic diseases in the People's Republic of China (P.R. China) requires novel approaches, particularly in the areas of diagnostics, mathematical modelling, monitoring, evaluation, surveillance and public health response. A comprehensive effort, involving the collaboration of 188 scientists (<85% from P.R. China) from 48 different institutions and universities (80% from P.R. China), covers this collection of 29 articles published in Parasites & Vectors. The research mainly stems from a research project entitled 'Surveillance and diagnostic tools for major parasitic diseases in P.R. China' (grant no. 2008ZX10004-011) and highlights the frontiers of research in parasitology. The majority of articles in this thematic series deals with the most important parasitic diseases in P.R. China, emphasizing Schistosoma japonicum, Plasmodium vivax and Clonorchis sinensis plus some parasites of emerging importance such as Angiostrongylus cantonensis. Significant achievements have been made through the collaborative research programme in the following three fields: (i) development of control strategies for the national control programme; (ii) updating the surveillance data of parasitic infections both in human and animals; and (iii) improvement of existing, and development of novel, diagnostic tools to detect parasitic infections. The progress is considerable and warrants broad validation efforts. Combined with the development of improved tools for diagnosis and surveillance, integrated and multi-pronged control strategies now pave the way for elimination of parasitic diseases in P.R. China. Experiences and lessons learned can stimulate control and elimination efforts of parasitic diseases in other parts of the world

Exploring the In-Race Adoption of Asian Children

A growing body of literature exists which explores the transracial adoption of Asian children into White/Caucasian families while there are no studies to date which capture the experiences of Asian/Asian American families who adopt Asian children. It is the researchers\u27 intent to build knowledge in the area as well as illuminate the need for further research

User's manual for the coupled mode version of the normal modes rotor aeroelastic analysis computer program

This User's Manual was prepared to provide the engineer with the information required to run the coupled mode version of the Normal Modes Rotor Aeroelastic Analysis Computer Program. The manual provides a full set of instructions for running the program, including calculation of blade modes, calculations of variable induced velocity distribution and the calculation of the time history of the response for either a single blade or a complete rotor with an airframe (the latter with constant inflow)

Schistosomiasis at the crossroad to elimination: review of eclipsed research with emphasis on the post-transmission agenda

While chronic schistosomiasis is pathologically well defined, the acute form of the disease is less well understood. It is generally agreed that early lesions, such as lung nodules and bladder polyps, are reversible, which impedes identification of the time elapsed since exposure. The intermediate stage between the acute and the chronic forms of schistosomiasis requires further investigation, as does the clinical stage due to lesions remaining after treatment. With current schistosomiasis control efforts gradually progressing to elimination, there is a need to focus on post-transmission schistosomiasis, which not only refers to remaining lesions from previous infections, but also accounts for the potential presence of surviving worms after treatment. This issue is particularly salient for migrants from endemic to non-endemic countries and should be kept in mind for returning expatriates from schistosomiasis-endemic countries. Negative stool examination or urine filtration are generally taken as indicative of cure since rectoscopy for Schistosoma mansoni infection, or cystoscopy for S. haematobium infection, are rarely performed. However, pathology of affected organs may persist indefinitely, while potentially remaining live worms could produce additional pathology. Hence, post-transmission schistosomiasis can prevail for years after elimination of the disease, and thus, warrant further attention

Sub-dekahertz ultraviolet spectroscopy of 199Hg+

Using a laser that is frequency-locked to a Fabry-Perot etalon of high finesse and stability, we probe the 5d10 6s 2S_1/2 (F=0) - 5d9 6s 2D_5/2 (F=2) Delta-m_F = 0 electric-quadrupole transition of a single laser-cooled 199Hg+ ion stored in a cryogenic radio-frequency ion trap. We observe Fourier-transform limited linewidths as narrow as 6.7 Hz at 282 nm (1.06 X 10^15 Hz), yielding a line Q = 1.6 X 10^14. We perform a preliminary measurement of the 5d9 6s2 2D_5/2 electric-quadrupole shift due to interaction with the static fields of the trap, and discuss the implications for future trapped-ion optical frequency standards.Comment: 4 pages, 4 figures, submitted for publicatio

Satisfaction with Cognitive Rehabilitation Delivered via the Internet in Persons with Acquired Brain Injury

We examined the level of satisfaction with cognitive rehabilitation delivered via the Internet in persons with moderate to severe acquired brain injury (ABI). Fifteen adults with moderate to severe ABI were randomized to 30 days of Internet-based active treatment (AT) or to a wait list (WL) group, and crossed over to the opposite condition after 30 sessions. Both caregivers and participants were assessed at three time points during the study. This study focused on participant satisfaction with receiving treatment in this manner. Though the results of this study showed no significant treatment effect, the vast majority of participants (&gt;87%) were satisfied with treatment. Treatment satisfaction accounted for 25% of additional variance in predicting lower family ratings of mood difficulties after final assessment (p&lt;.03). Greater satisfaction with treatment was positively correlated with greater employment rate after treatment (r=.63, p=.02), as well as lower family ratings of memory and mood difficulties after final assessment (r=-.59, p=.03; r=-.58, p=.03,). Results suggest that treatment satisfaction in persons with ABI is related to less activity limitations, and maintaining employment after cognitive rehabilitation delivered via the Internet. 

Incremental validity of psychological flexibility, anxiety sensitivity, and mindfulness in the prediction of panic disorder symptomology and life satisfaction

Cognitive behavioral therapy (CBT) is a psychotherapeutic approach that has been demonstrated to be effective in the treatment of panic disorder. Reducing the fear of anxiety-related sensations (anxiety sensitivity) is a core putative mechanism of CBT for panic disorder. Acceptance and Commitment Therapy (ACT) is a transdiagnostic therapy approach that shares some similarities with traditional CBT but differs in many key aspects. ACT has attracted interest and generated debate in academic and clinical domains. Research suggests that ACT is an efficacious treatment in the context of panic disorder and other anxiety-related disorders. However, the incremental utility of ACT-related constructs (e.g., psychological flexibility, mindfulness) relative to traditional CBT-related constructs (e.g., anxiety sensitivity) in the prediction of panic symptomology and life satisfaction is unclear. The few results that exist in this area have been mixed. The present study found anxiety sensitivity and psychological flexibility supplemented one another in the prediction of panic disorder symptoms and life satisfaction. Mindfulness was not a significant predictor of either panic or life satisfaction. The results suggest that both traditional and third wave CBT constructs (i.e., anxiety sensitivity and psychological flexibility) are useful predictors of panic symptoms and life satisfaction