A Broad Spectrum Defense Against Adversarial Examples

Machine learning models are increasingly employed in making critical decisions across a wide array of applications. As our dependence on these models increases, it is vital to recognize their vulnerability to malicious attacks from determined adversaries. In response to these adversarial attacks, new defensive mechanisms have been developed to ensure the security of machine learning models and the accuracy of the decisions they make. However, many of these mechanisms are reactionary, designed to defend specific models against a known specific attack or family of attacks. This reactionary approach does not generalize to future yet to be developed attacks. In this work, we developed Broad Spectrum Defense (BSD) as a defensive mechanism to secure any model against a wide range of attacks. BSD is not reactionary, and unlike most other approaches, it does not train its detectors using adversarial data, hence removing an inherent bias present in other defenses that rely on having access to adversarial data. An extensive set of experiments showed that BSD outperforms existing detector-based methods such as MagNet and Feature Squeezing. We believe BSD will inspire a new direction in adversarial machine learning to create a robust defense capable of generalizing to existing and future attacks

Why Would Berlin Mischaracterize Rousseau?

Isaiah Berlin’s “Two Concepts of Liberty” introduced the terminology of negative and positive liberty in 1958. Berlin asserts that Jean-Jacques Rousseau’s political philosophy (particularly “On the Social Contract’) exemplifies the dangerous notion of positive liberty. I argue that Berlin’s presentation distorts Rousseau’s work and overlooks resources that exculpate Rousseau with regard to despotic regimes. Berlin’s interpretation and portrayal of Rousseau are examined. Berlin’s claims are examined mainly in light of Rousseau’s “Third Discourse” (The Discourse on Political Economy), as opposed to Berlin’s emphasis on “The Social Contract”. This work contains Rousseau’s normative commentary on the principles of good government. The adequacy of Berlin’s positive/negative liberty framework is tested with respect to Rousseau’s own claims

COVID-19_Maine Campus_Letter to the Editor

Letter to the Editor by Sean McGuire submitted to the Maine Campus Newspaper regarding the employment of students in the University of Maine\u27s front line response to the COVID-19 pandemic

Peripherally Inserted Central Catheters vs Peripheral Cannulas for Delivering Parenteral Nutrition in Neonates

CLINICAL QUESTION: Is parenteral nutrition via peripherally inserted central catheters (PICCs) associated with better delivery of nutrition and growth and fewer adverse events compared with short peripheral cannulas in neonates? BOTTOM LINE: Compared with short peripheral cannulas, parenteral nutrition via PICCs is associated with better nutrient delivery and lower rates of subsequent catheters or cannulas placed and is not associated with increased rates of invasive infection

Have 24 hour news channels had their day?

Are 24 hour news channels - which transformed news broadcasting 30 years ago, still fit for purpose? Or in an age of open interactive media are these closed, linear channels no longer providing the service consumers increasingly want

Have 24 hour news channels had their day?

Are 24 hour news channels - which transformed news broadcasting 30 years ago, still fit for purpose? Or in an age of open interactive media are these closed, linear channels no longer providing the service consumers increasingly want

Tracer-based assessment of flow paths, storage and runoff generation in northern catchments : a review

Peer reviewedPostprin

Improving developmental timelines through the generation of predictive scale down models

The importance of scale down models in biomanufacturing has increased with accelerating program timelines and desired efficiency improvements. To meet these demands, it is necessary not only to have a platform scale down model that can reliably perform across early programs, but to also understand the key aspects of the model so as to be able to adapt it to specific program needs and to different manufacturing equipment and scales. We are working to create this level of understanding by combining both traditional engineering principles with more detailed knowledge of how scale differences commonly impact cell culture behavior. As part of this process, we have systematically characterized the volumetric mass transfer coefficients (kLas) for our laboratory and manufacturing bioreactors and have used this data to determine the scaling criteria that most accurately captures the differences between our systems. We then modified the setup of and general practices used for our laboratory scale bioreactors based on these results to better align with the predictions of the identified scaling criteria. Through this process we were able to rapidly establish scale down models for 3 early stage programs at 2 different manufacturing scales. These models were used to transfer these programs following a single clone selection run at the 3 L scale and without additional runs at intermediate scales. The identification of the critical scaling criteria for our manufacturing bioreactors also allowed for the direct transfer of a late stage program between suites without engineering runs. We are currently expanding this work to understand how changes to our scale down practices have impacted additional characteristics of our cultures apart from the standardly measured attributes, and how these characteristics can be used to drive more predictive models

Exploration of human brain tumour metabolism using pairwise metabolite-metabolite correlation analysis (MMCA) of HR-MAS 1H NMR spectra.

METHODS: We quantified 378 HRMAS 1H NMR spectra of human brain tumours (132 glioblastomas, 101 astrocytomas, 75 meningiomas, 37 oligodendrogliomas and 33 metastases) from the eTumour database and looked for metabolic interactions by metabolite-metabolite correlation analysis (MMCA). RESULTS: All tumour types showed remarkably similar metabolic correlations. Lactate correlated positively with alanine, glutamate with glutamine; creatine + phosphocreatine (tCr) correlated positively with lactate, alanine and choline + phosphocholine + glycerophosphocholine (tCho), and tCho correlated positively with lactate; fatty acids correlated negatively with lactate, glutamate + glutamine (tGlut), tCr and tCho. Oligodendrogliomas had fewer correlations but they still fitted that pattern. CONCLUSIONS: Possible explanations include (i) glycolytic tumour cells (the Warburg effect) generating pyruvate which is converted to lactate, alanine, glutamate and then glutamine; (ii) an association between elevated glycolysis and increased choline turnover in membranes; (iii) an increase in the tCr pool to facilitate phosphocreatine-driven glutamate uptake; (iv) lipid signals come from cytosolic lipid droplets in necrotic or pre-necrotic tumour tissue that has lower concentrations of anabolic and catabolic metabolites. Additional metabolite exchanges with host cells may also be involved. If tumours co-opt a standard set of biochemical mechanisms to grow in the brain, then drugs might be developed to disrupt those mechanisms

Identification of a pan-cancer oncogenic microRNA superfamily anchored by a central core seed motif

MicroRNAs modulate tumorigenesis through suppression of specific genes. As many tumour types rely on overlapping oncogenic pathways, a core set of microRNAs may exist, which consistently drives or suppresses tumorigenesis in many cancer types. Here we integrate The Cancer Genome Atlas (TCGA) pan-cancer data set with a microRNA target atlas composed of publicly available Argonaute Crosslinking Immunoprecipitation (AGO-CLIP) data to identify pan-tumour microRNA drivers of cancer. Through this analysis, we show a pan-cancer, coregulated oncogenic microRNA ‘superfamily’ consisting of the miR-17, miR-19, miR-130, miR-93, miR-18, miR-455 and miR-210 seed families, which cotargets critical tumour suppressors via a central GUGC core motif. We subsequently define mutations in microRNA target sites using the AGO-CLIP microRNA target atlas and TCGA exome-sequencing data. These combined analyses identify pan-cancer oncogenic cotargeting of the phosphoinositide 3-kinase, TGFβ and p53 pathways by the miR-17-19-130 superfamily members