Permafrost

Mike and a brave group of volunteers battle the elements on their journey to get help and save there peopl

Profiling changes in the metastatic potential of breast cancer cells exposed to flow

Most cancer related deaths can be directly attributed to blood bourne metastasis.Metastasis is the process by which tumor cells leave the initial tumor travel through thecirculatory or lymphatic system to distant sites where secondary tumors are formed.One important part of metastasis is epithelial to mesenchymal transition (EMT), inwhich cells lose their epithelial cell morphology and gain a mesenchymal morphology.This transition causes enhanced migratory capacity, invasiveness, and resistance tocell death, creating a more metastatic cell. In this study we used a parallel plate flowchamber to create conditions that would encourage EMT in breast cancer cells. Severalbreast cancer cell lines were exposed to high shear stress (10 dyn/cm2) for 20 hours.RNA was collected from static and flow exposed cells. RT-qPCR was used to comparethe expression of four genes known to be related to EMT or cell invasiveness. Wefound that TSP-1 gene expression was strongly upregulated, MMP-14 was slightlyupregulated, ICAM-1 was slightly downregulated, and TGFR1 gene expression didnot change. TSP-1 has been shown to increase tumor cell migration and invasivenessand MMP-14 has also been associated with increased tumor cell invasiveness. ICAM-1is an intercellular adhesion molecule that plays different roles in cell to cell adhesion.The loss of ICAM-1 and the up regulation of TSP-1 and MMP-14 show that the cellsexposed to flow lose some intercellular interaction and gain increased mobility andinvasiveness, all of which is indicative of EMT. These results show for the first timethat fluid forces can upregulate genes involved in cancer cell EMT. This will be used infuture studies to investigate more about the metastatic potential of breast cancer cells.1

On the bias-variance tradeoff : textbooks need an update

L’objectif principal de cette thèse est de souligner que le compromis biais-variance n’est pas toujours vrai (p. ex. dans les réseaux neuronaux). Nous plaidons pour que ce manque d’universalité soit reconnu dans les manuels scolaires et enseigné dans les cours d’introduction qui couvrent le compromis. Nous passons d’abord en revue l’historique du compromis entre les biais et les variances, sa prévalence dans les manuels scolaires et certaines des principales affirmations faites au sujet du compromis entre les biais et les variances. Au moyen d’expériences et d’analyses approfondies, nous montrons qu’il n’y a pas de compromis entre la variance et le biais dans les réseaux de neurones lorsque la largeur du réseau augmente. Nos conclusions semblent contredire les affirmations de l’oeuvre historique de Geman et al. (1992). Motivés par cette contradiction, nous revisitons les mesures expérimentales dans Geman et al. (1992). Nous discutons du fait qu’il n’y a jamais eu de preuves solides d’un compromis dans les réseaux neuronaux lorsque le nombre de paramètres variait. Nous observons un phénomène similaire au-delà de l’apprentissage supervisé, avec un ensemble d’expériences d’apprentissage de renforcement profond. Nous soutenons que les révisions des manuels et des cours magistraux ont pour but de transmettre cette compréhension moderne nuancée de l’arbitrage entre les biais et les variances.The main goal of this thesis is to point out that the bias-variance tradeoff is not always true (e.g. in neural networks). We advocate for this lack of universality to be acknowledged in textbooks and taught in introductory courses that cover the tradeoff. We first review the history of the bias-variance tradeoff, its prevalence in textbooks, and some of the main claims made about the bias-variance tradeoff. Through extensive experiments and analysis, we show a lack of a bias-variance tradeoff in neural networks when increasing network width. Our findings seem to contradict the claims of the landmark work by Geman et al. (1992). Motivated by this contradiction, we revisit the experimental measurements in Geman et al. (1992). We discuss that there was never strong evidence for a tradeoff in neural networks when varying the number of parameters. We observe a similar phenomenon beyond supervised learning, with a set of deep reinforcement learning experiments. We argue that textbook and lecture revisions are in order to convey this nuanced modern understanding of the bias-variance tradeoff

Creating an Incident Response Plan

In any organization, it is important to be prepared in the event of a major incident that might impact and impede critical operations. The best practice that an organization can take to ensure that such an incident may be handled well is to develop a plan in preparation for such an event. In order to aid my organization in preparing for adverse incidents, I have worked to create an incident response plan based on our organization. This plan is developed to cater to our manufacturing organization with 4 major locations and an IT team of about a dozen individuals. By having an incident response plan developed, we can be more effective at managing any incidents that might occur

Acute Effects of Multi-Joint Eccentric Exercise on Lower Extremity Muscle Activation Measured During Land and Water Walking

Although prior literature has established the preliminary clinical benefits of aquatic exercise across various clinical populations, there is a need to explore the potential for including aquatic-based movement as a key component of a multi-modal approach toward improving mobility and reducing fall risk. Eccentric exercise may complement aquatic exercise given that movements performed in water immersion tend to be low impact. Eccentric exercise may also improve the passive stiffness of lower extremity extensors, which gives an additional rationale for the potential of eccentric exercise to reduce fall risk when combined with aquatic exercise. There may also be an acute response to spinal reflex activity post-eccentric exercise, which could enhance the benefit of performing aquatic exercise if eccentric exercise is performed immediately prior. The purpose of this study was to compare lower-limb muscle activation during gait performed in water versus on land, before and after a short bout of eccentric exercise, in order to investigate the potential of a multi-modal approach toward improving gait abnormalities that relate to fall risk in older adults. Twenty-six healthy, recreationally active young adults completed the study. Each participant walked on land and in water, both prior to and after eccentric exercise for 2-min each while root-mean-square (RMS) muscle activity of the tibialis anterior (TA), medial gastrocnemius (GM), biceps femoris (BF), and vastus lateralis (VL) were recorded during the swing and stance phases of gait, using surface electromyography. A two-way within-subjects analysis of variance was used to evaluate for main effects and interactions. Main effects of environment were observed across all measures of muscle activation (F = 4.5 – 602.6, p \u3c0.001 – 0.036) except for BF RMS during the swing phase (F = 0.2, p = 0.699). Co-activation of the thigh during swing was the only measure to reveal an environment × eccentric exercise interaction (F = 5.4, p \u3c 0.001) and main effect of eccentric exercise (F = 7.4, 2 p = 0.008).The significant interaction on Co-activation of the thigh during swing appeared to be influenced by a non-significant reduction in VL RMS observed for post-eccentric exercise land walking. This suggests that participants may have adopted a different motor strategy, possibly anticipating the greater vertical ground reaction forces during foot impact in land walking compared to water walking, leading to reduced VL activation during swing. The results of this study provide evidence that additional research is warranted and may be aimed at exploring the potential of a multi-modal training approach involving aquatic treadmill walking and eccentric exercise to enhance mobility and address fall risk in clinical populations

Exploring Flexibility in 83(b) Elections: A Tax Policy Proposal

Property awards, such as equity, are taxable to the recipient and have tax implications for employers, too. Without a recipient making an 83(b) election, property awards are taxable when they are granted. For awards that have vesting requirements or are considered “restricted,” they are generally taxable upon vesting. However, making an 83(b) election allows recipients of restricted property awards to be taxed as if the property were vested, meaning more income will shift from ordinary tax rate treatment to preferential tax rate treatment. The preferential tax system is foundational to the 83(b) election. Advocates believe that preferential tax rates in an 83(b) context promote economic growth and encourage efficient capital allocation. However, critics contend that 83(b) elections disproportionately benefit the wealthy because they require electors to pay taxes earlier, which may disadvantage lower-income individuals. Two similarly situated employees may receive significantly different tax treatment based on the type of compensation and whether they make the 83(b) election. Furthermore, the complexities and rigidity of this provision of the tax code create their own inequities. Although the 83(b) election grants flexibility and control for taxpayers, it needs more flexibility by extending the deadline to file. Perhaps providing downside protection for 83(b) electors can encourage more employers to grant property to their employees and service providers. Ultimately, these solutions will allow more people to enjoy the benefits of preferential tax treatment, thereby making preferential tax rates more equitable for everyone