Replication of mixing achieved in large co-rotating screw extruder using a novel laboratory 10-100g minimixer

YesWhen compounding polymers with additives to develop materials at specifications (colouring plastics is the simplest example), the difficulties is in getting the formulation right the first time. Also, when developing completely new materials such as in nanotechnology applications, there is a need to do the initial trials safely and with as small quantities as possible to enable a wide range of experimentation. Wiith traditional applications, often the initial compounding formulation is done using small single or twin screw extruders but with machines that have a fair output to instruct the large scale operation. This step is costly in material wastage and time but more importantly it often does not provide the right formulation which in turn results in bigger wastage cost at the industrial scale before the right formulation is eventually obtained. With the very new material formulations, any reduction in cost of development is always essential. With these aims in mind, we have developed a new minimixer capable of handling tiny quantities of order 10-100g but the minimixer is capable of reproducing the very high mixing conditions experienced in large machines. This invention provides a new opportunity to develop new products quickly, safely and cheaply. The application is not restricted to polymers and can be extended to other soft materials. It has also other spin-offs as a research tool for studying mixing and developing new, more efficient, mixing flows. In this paper we explain the principle of operation we have engineered to produce such intense mixing. Basically, the device is based on combining two opposing flows: a single screw extruder circulation flow with a twin screw extruder mixing flow. The mixing is carried out as a batch but on its completion, the single screw extruder flow is reversed and becomes co-current with the twin extruder flow to enable the discharging of the batch through a die. In the paper we present mixing data obtained with various polymer-additive combinations tested in the minimixer under various conditions of screw speeds, mixing times and temperatures and at the larger scale to underpin the operation of this novel mixer. The quality of mixing of the extrudate was measured using a variety of methods depending on applications: using image analysis of microtome sections of the extrudate or of blown film samples produced from the formulations or measuring electrical properties

When and where do feed-forward neural networks learn localist representations?

According to parallel distributed processing (PDP) theory in psychology, neural networks (NN) learn distributed rather than interpretable localist representations. This view has been held so strongly that few researchers have analysed single units to determine if this assumption is correct. However, recent results from psychology, neuroscience and computer science have shown the occasional existence of local codes emerging in artificial and biological neural networks. In this paper, we undertake the first systematic survey of when local codes emerge in a feed-forward neural network, using generated input and output data with known qualities. We find that the number of local codes that emerge from a NN follows a well-defined distribution across the number of hidden layer neurons, with a peak determined by the size of input data, number of examples presented and the sparsity of input data. Using a 1-hot output code drastically decreases the number of local codes on the hidden layer. The number of emergent local codes increases with the percentage of dropout applied to the hidden layer, suggesting that the localist encoding may offer a resilience to noisy networks. This data suggests that localist coding can emerge from feed-forward PDP networks and suggests some of the conditions that may lead to interpretable localist representations in the cortex. The findings highlight how local codes should not be dismissed out of hand

Oral History Interview: Selma Gale Martin

This interview is one of series conducted concerning the Oral History of Appalachia. Selma Gale Martin discusses her childhood, her education at Marshall University, and also gives a detailed description of the Huntington flood of 1937.https://mds.marshall.edu/oral_history/1227/thumbnail.jp

Control Diseases and Insect Pests of Apples and Pears

Production of high quality fruit in home plantings depends on the control of several insect pests and diseases. The information in this circular is designed to assist the home grower produce good quality fruit. Carefully follow the spray schedule. Elimination of one or two sprays from the schedule or haphazard application of spray materials, usually results in low-quality diseased or insect- damaged fruit. Keep farm and home fruit plantings small, just large enough to supply fruit for the family. Many plantings are too large to be taken care of adequately. For home use, it is far better to have two or three properly maintained trees than a neglected large orchard. For spraying equipment, small power sprayers are best to use, although hand operated ones such as the trombone-type sprayers are much lower in cost. The latter type of sprayer will spray branches 25 to 30 feet from the ground but care has to be taken to see that all surfaces are completely covered by the spray. A sprayer with an adjustable nozzle is desirable

An emerging role for stress granules in neurodegenerative disease and hearing loss

Stress granules (SGs) are membrane-less cytosolic assemblies that form in response to stress (e.g., heat, oxidative stress, hypoxia, viral infection and UV). Composed of mRNA, RNA binding proteins and signalling proteins, SGs minimise stress-related damage and promote cell survival. Recent research has shown that the stress granule response is vital to the cochlea's response to stress. However, emerging evidence suggests stress granule dysfunction plays a key role in the pathophysiology of multiple neurodegenerative diseases, several of which present with hearing loss as a symptom. Hearing loss has been identified as the largest potentially modifiable risk factor for dementia. The underlying reason for the link between hearing loss and dementia remains to be established. However, several possible mechanisms have been proposed including a common pathological mechanism. Here we will review the role of SGs in the pathophysiology of neurodegenerative diseases and explore possible links and emerging evidence that they may play an important role in maintenance of hearing and may be a common mechanism underlying age-related hearing loss and dementia

Coherence Time Effects on J/psi Production and Suppression in Relativistic Heavy Ion Collisions

Using a coherence time extracted from high precision proton-nucleus Drell-Yan measurements and a nuclear absorption cross section extracted from pA charmonium production experiments, we study J/psi production and absorption in nucleus-nucleus collisions. We find that coherence time effects are large enough to affect the measured J/psi-to-Drell-Yan ratio. The S+U data at 200A GeV/c measured by NA38 are reproduced quantitatively without the introduction of any new parameters. However, when compared with recent NA50 measurements for Pb+Pb at 158A GeV/c, the data is not reproduced in trend or in magnitude.Comment: 8 pages, 2 figure

Are there any ‘object detectors’ in the hidden layers of CNNs trained to identify objects or scenes?

Various methods of measuring unit selectivity have been developed with the aim of better understanding how neural networks work. But the different measures provide divergent estimates of selectivity, and this has led to different conclusions regarding the conditions in which selective object representations are learned and the functional relevance of these representations. In an attempt to better characterize object selectivity, we undertake a comparison of various selectivity measures on a large set of units in AlexNet, including localist selectivity, precision, class-conditional mean activity selectivity (CCMAS), network dissection,the human interpretation of activation maximization (AM) images, and standard signal-detection measures. We find that the different measures provide different estimates of object selectivity, with precision and CCMAS measures providing misleadingly high estimates. Indeed, the most selective units had a poor hit-rate or a high false-alarm rate (or both) in object classification, making them poor object detectors. We fail to find any units that are even remotely as selective as the 'grandmother cell' units reported in recurrent neural networks. In order to generalize these results, we compared selectivity measures on units in VGG-16 and GoogLeNet trained on the ImageNet or Places-365 datasets that have been described as 'object detectors'. Again, we find poor hit-rates and high false-alarm rates for object classification. We conclude that signal-detection measures provide a better assessment of single-unit selectivity compared to common alternative approaches, and that deep convolutional networks of image classification do not learn object detectors in their hidden layers.Comment: Published in Vision Research 2020, 19 pages, 8 figure

The ototoxic drug cisplatin localises to stress granules altering their dynamics and composition

Cisplatin is an effective platinum-based chemotherapeutic with several side effects, including ototoxicity. Cochlear cells have low rates of proliferation yet are highly susceptible to cisplatin. We hypothesized that cisplatin ototoxicity may be caused by cisplatin-protein interactions rather than cisplatin-DNA interactions. Two known cisplatin-binding proteins are involved in the stress granule (SG) response. SGs are a pro-survival mechanism involving formation of transient ribonucleoprotein complexes during stress. We examined the effects of cisplatin on SG dynamics and composition in cell lines derived from the cochlea and retinal pigment epithelium. Cisplatin-induced SGs are significantly diminished in size and quantity compared to arsenite-induced SGs and are persistent after 24 hours recovery. Additionally, cisplatin pre-treated cells were unable to form a typical SG response to subsequent arsenite stress. Cisplatin-induced SGs had significant reductions in the sequestration of eIF4G and proteins RACK1 and DDX3X. Live cell imaging of cisplatin-TR revealed localisation to SGs and retention for at least 24 hours. We show cisplatin-induced SGs have impaired assembly, altered composition and are persistent, providing evidence of an alternate mechanism for cisplatin-induced ototoxicity via an impaired SG response