A philosophy of science approach to the amyloid hypothesis of Alzheimer's disease.

Disputes about the scientific validity of the amyloid-ß hypothesis of Alzheimer's disease have been held since the early 1990s, with little constructive progress made between opposing sides despite recent therapeutic progress. Here, I argue that philosophy of science can improve the chance of constructive debate by giving researchers technical language to describe and assess scientific progress. To do so, I interpret the amyloid hypothesis using a modified version of the research programme concept from philosopher of science Imre Lakatos. I first outline the amyloid-ß hypothesis and study critiques of its central place in Alzheimer's research. Then, I draw on the complexity of amyloid-ß and Alzheimer's research to discuss the limits of using concepts from popular philosophers of science Karl Popper or Thomas Kuhn, before finally arguing that an adaptation of the research programme concept can foster constructive debates about the science of Alzheimer's and within it. I will argue that the amyloid-ß hypothesis has contributed to significant progress in the Alzheimer's field based on what Lakatos called the "positive heuristic" (motivating the programme to test its predictions) and the "negative heuristic" (protecting the programme from refutation). I consider the amyloid research agenda to be progressive despite the fact that its claims about disease aetiology could be wrong.

Against "silent" retractions in neuroscience.

When an academic paper is published in a journal that assigns a digital object identifier (DOI) to papers, this is a de facto fait accompli. Corrections or retractions are supposed to follow a specific protocol, especially in journals that claim to follow the Committee on Publication Ethics (COPE) guidelines. In this paper, we highlight a case of a new, fully open access neuroscience journal that claims to be COPE-compliant, yet has silently retracted two papers since all records, bibliometrics, and PDF files related to their existence have been deleted from the journal's website. Although this phenomenon does not seem to be common in the neurosciences, we consider that any opaque corrective measures in journals whose papers could be cited may negatively impact the wider neuroscience literature and community. Instead, we encourage transparency in retraction to promote truthfulness and trustworthiness.

Impact of flexible noise control (FNC) image processing parameters on portable chest radiography.

There is a lack of understanding in the performance of flexible noise control (FNC) processing, which is used in digital radiography on a scanner vendor and has four parameters each involving multiple options. The aim of this study was to investigate the impact of FNC on portable chest imaging. An anthropomorphic chest phantom was imaged using a clinical chest program with 85 kV and five radiation dose levels at 40″ source-to-image distance with software-based scatter reduction method. All images were processed without and with FNC. Noise analysis was performed in two regions of interest (ROI) on subtracted noise-only images, and line profiles were generated through a lung-rib interface. In addition, noise power spectra (NPS) analysis was performed in solid water phantoms of 10 and 20 cm thicknesses, using the same acquisition program and a range of dose levels. Last, feedback on retrospectively deidentified, reprocessed, and randomized clinical images from 20 portable chest exams was gathered from two thoracic radiologists. Noise reduction performances of FNC were demonstrated, with the level depending on specific FNC parameters, dose levels, ROI placement, and phantom sizes. Higher frequency textural patterns were revealed through the NPS analysis, which varied based on FNC parameters, dose levels, and phantom sizes. Overall, the vendor default parameter FGA0.5 yielded the highest noise reduction and textural artifacts. Radiologist feedback showed consistent preference of no FNC due to the presence of textural artifacts in the FNC-processed images. An algorithm improvement to avoid introducing artifacts would be desired.

Triplex real-time PCR for detection of Crithidia mellificae and Lotmaria passim in honey bees.

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.

Defining the common femoral artery: Insights from the femoral arterial access with ultrasound trial.

OBJECTIVE: We sought to establish the typical location of the common femoral artery (CFA) bifurcation, the origin and most inferior reflection of the inferior epigastric artery (IEA) relative to the femoral head (FH) and whether patient demographics predicted anatomical variations. BACKGROUND: In the absence of ultrasound guidance or prior imaging, the precise location of the CFA bifurcation and IEA can only be determined following access site angiography. Fluoroscopic landmarks are commonly used to estimate the location of the CFA bifurcation, but the position of the IEA is less well characterized. METHODS: Prospectively collected data on 989 patients with femoral angiography in the FAUST trial were analyzed. The level of CFA bifurcation and the origin and most inferior reflection of the IEA were classified by angiography. Logistic regression was used to explore whether baseline demographics were associated with anatomic variations. RESULTS: The CFA bifurcation occurs below the middle 1/3rd of the femoral head in 95% of patients, and no patient factors are predictive of a high bifurcation. The IEA origin has a more variable anatomically pattern, with high BSA, male gender, and white race associated with a low IEA origin. CONCLUSION: Operators should attempt to access the CFA at the level of the middle 1/3rd of the FH to maximize the chance of CFA cannulation. However, this location carries an 11% risk of being at or above the IEA origin. Baseline demographics were of limited utility for predicting anatomic variants of the CFA bifurcation and the course of the IEA. © 2016 Wiley Periodicals, Inc.