Using a 10.5-GHz resonant electro-optic modulator placed inside a resonant optical cavity, we generated an optical frequency comb with a span wider than 3 THz. The optical resonator consists of three mirrors, with the output coupler being a thin Fabry-Perot cavity with a free spectral range of 2 THz and a finesse of 400. Tuning this filter cavity onto resonance with a particular high-order sideband permits efficient output coupling of the desired sideband power from the comb generator, while keeping all other sidebands inside for continued comb generation. This spectrally pure output light was then heterodyne detected by another laser with a frequency offset of the order of 1 THz.
Currently, light microscopic examination of cell morphology cannot discriminate Crithidia mellificae and Lotmaria passim with 100% certainty. Here, a minor groove-binding (MGB) probe-based multiplex real-time PCR assay was developed for the simultaneous and quantitative detection of C. mellificae and L. passim in honey bees. A conserved Hymenoptera 18S rRNA gene was built in as an internal control that allows accurate detection of PCR inhibition and failure of DNA extraction. The newly developed assay was also applied to field samples. Of 21 honey bee colonies (446 bees) sampled from six counties in both central and eastern Massachusetts, 3 colonies (14.29%) and 8 bees (1.79%) were infected with L. passim, and 1 colony (4.76%) and 1 bee (0.22%) with C. mellificae. Our data showed a low rate of trypanosomatid infection, and L. passim was more prevalent than C. mellificae in honey bee samples in Massachusetts.
Background: Therapeutic research into Alzheimer’s disease (AD) has been dominated by the amyloid cascade hypothesis (ACH) since the 1990s. However, targeting amyloid in AD patients has not yet resulted in highly significant disease-modifying effects. Furthermore, other promising theories of AD etiology exist. Objective: We sought to directly investigate whether the ACH still dominates the opinions of researchers working on AD and explore the implications of this question for future directions of research. Methods: During 2019, we undertook an international survey promoted with the help of the Alzheimer’s Association with questions on theories and treatments of AD. Further efforts to promote a similar study in 2021 did not recruit a significant number of participants. Results: 173 researchers took part in the 2019 survey, 22% of which held “pro-ACH” opinions, tended to have more publications, were more likely to be male, and over 60. Thus, pro-ACH may now be a minority opinion in the field but is nevertheless the hypothesis on which the most clinical trials are based, suggestive of a representation bias. Popular vote of all 173 participants suggested that lifestyle treatments and anti-tau drugs were a source of more therapeutic optimism than anti-amyloid treatments. Conclusion: We propose a more democratic research structure which increases the likelihood that promising theories are published and funded fairly, promotes a broader scientific view of AD, and reduces the larger community’s dependence on a fragile economic model.
Given the unknown therapeutic value of targeting Alzheimer’s disease pathology and the discovery of robust risk factors for dementia, non-pharmacological risk reduction (RR) is increasingly offered as an alternative to targeting Alzheimer’s disease pathology. While RR will surely be a useful tool to make public health gains, we propose solutions to three possible issues with over-reliance on multi-domain interventions to achieve RR: limited individual impact, an exclusive focus on later life, and overlooking social determinants of dementia. We argue in favor of a broader debate within the research community and greater society about how different therapeutic avenues should be explored.
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The amyloid cascade hypothesis (ACH) has dominated contemporary biomedical research into Alzheimer's disease (AD) since the 1990s but lacks confirmation by successful clinical trials of anti-amyloid medicines in human AD. In this uncertain period regarding the centrality of betaamyloid (Aβ) in the AD disease process, and with the community apparently divided about the ACH's validity, we used citation practices as a proxy for measuring how researchers have invested their belief in the hypothesis between 1992 and 2019. We sampled 445 articles citing Hardy & Higgins ("HH92") and classified the polarity of their HH92 citation according to Greenberg (2009)'s citation taxonomy of positive, neutral, and negative citations, and then tested four hypotheses. We identified two major attitudes towards HH92: a majority (62.7%) of neutral attitudes with consistent properties across the time period, and a positive attitude (35.0%), tending to cite HH92 earlier on within the bibliography as time went by, tending to take HH92 as
The qualitative survey by Susanne Röhr and colleagues recently published in the journal 1 on changing urban spaces to reduce dementia risk marks a step towards what they term the 'co-creation' of risk-reducing urban environments (p. 1). 1 It also marks an important conceptual shift away from the individual to the environment's role in dementia prevention.
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