1,226 research outputs found
Predicting college basketball match outcomes using machine learning techniques: some results and lessons learned
Most existing work on predicting NCAAB matches has been developed in a
statistical context. Trusting the capabilities of ML techniques, particularly
classification learners, to uncover the importance of features and learn their
relationships, we evaluated a number of different paradigms on this task. In
this paper, we summarize our work, pointing out that attributes seem to be more
important than models, and that there seems to be an upper limit to predictive
quality
WikiM: Metapaths based Wikification of Scientific Abstracts
In order to disseminate the exponential extent of knowledge being produced in
the form of scientific publications, it would be best to design mechanisms that
connect it with already existing rich repository of concepts -- the Wikipedia.
Not only does it make scientific reading simple and easy (by connecting the
involved concepts used in the scientific articles to their Wikipedia
explanations) but also improves the overall quality of the article. In this
paper, we present a novel metapath based method, WikiM, to efficiently wikify
scientific abstracts -- a topic that has been rarely investigated in the
literature. One of the prime motivations for this work comes from the
observation that, wikified abstracts of scientific documents help a reader to
decide better, in comparison to the plain abstracts, whether (s)he would be
interested to read the full article. We perform mention extraction mostly
through traditional tf-idf measures coupled with a set of smart filters. The
entity linking heavily leverages on the rich citation and author publication
networks. Our observation is that various metapaths defined over these networks
can significantly enhance the overall performance of the system. For mention
extraction and entity linking, we outperform most of the competing
state-of-the-art techniques by a large margin arriving at precision values of
72.42% and 73.8% respectively over a dataset from the ACL Anthology Network. In
order to establish the robustness of our scheme, we wikify three other datasets
and get precision values of 63.41%-94.03% and 67.67%-73.29% respectively for
the mention extraction and the entity linking phase
Beware of the Ostrich Policy: End-Users' Perceptions Towards Data Transparency and Control
End users' awareness about the data they share, the purpose of sharing that
data, and their control over it, is key to establishing trust and eradicating
privacy concerns. We experimented on personal data management by prototyping a
Point-of-Interest recommender system in which data collected on the user can be
viewed, edited, deleted, and shared via elements in the User Interface. Based
on our qualitative findings, in this paper we discuss "The ostrich policy"
adopted by end users who do not want to manage their personal data. We sound a
waking whistle to design and model for personal data management by
understanding end users' perceptions towards data transparency and control.Comment: Human Centered AI workshop (HCAI) at the 35th Conference on Neural
Information Processing Systems (NeurIPS), 13 December, 202
Two-component Hydrogel as Biomimetic Vitreous Substitutes
The vitreous humor of the eye is a biological hydrogel principally composed of fibrillary collagen interspersed with semi-flexible polyelectrolyte, hyaluronic acid (HA). Certain pathological conditions necessitate its removal and replacement. Current vitreous substitutes, such as silicone oils and perfluorocarbons, are hydrophobic, do not resemble the properties of the vitreous, and have known complications. An ideal vitreous substitute should have properties of the natural vitreous, perform its functions, and be biocompatible in the eye. Inspired by the structure and composition of the natural vitreous, we used bio-mimicry to develop an injectable two-component hydrogel. The hydrogel is composed of a fibrillary gellan, an analogue of collagen, and a semi-flexible polyelectrolyte poly[methacrylamide-co-(methacrylic acid)], an analogue of hyaluronic acid, both endowed with thiol cross-linkers for reversible covalent linkage. The gellan, in the polymeric mixture, undergoes coil-helix transition near physiological temperature, enabling instantaneous in situ physical gelation of the solution. The thiol cross-linkers that later oxidize to disulfides under physiological conditions, make the hydrogel non-absorbable, non-degradable, and reversible, for facile removal if needed.
We used response surface methodology to investigate the structure-property relationships of eleven two-component hydrogels, and identified two hydrogel formulations that match the primary properties of the vitreous. We determined how each component of the hydrogel affects their optical, mechanical, sol-gel transition temperature, and osmotic swelling properties. All the hydrogels were transparent to visible light, with density and refractive indexes nearly equivalent to those of the natural vitreous. The shear storage moduli of the hydrogels, at 1Hz, ranged from 3 to 358 Pa, and the sol-gel transition temperatures, from 35.5 to 43 °C. In addition, as expected, all the hydrogels swelled in physiological solutions. Interestingly, we discovered that the relatively large swelling capacity of the semi-flexible ionic copolymer was significantly restricted by the minimally swellable fibrillary gellan network. The tightly swollen gel of two dissimilar networks produced Donnan osmotic swelling pressure in physiological solutions, which is also the driving force for re-attachment of the retina. Insights from the biomimetic nature of the gel, led us to propose that the natural vitreous also exhibits controlled swelling, where ionic HA’s swelling capacity is restricted by fibrillary collagen. The Donnan swelling pressure produced by the tightly swollen vitreous gel maintains the delicate internal structure of the eye, and perhaps plays a critical role during the ocular development.
We evaluated the biocompatibility of the two optimized formulations of the hydrogels on different cell lines, and in rabbits. Both hydrogels were found to be biocompatible on primary porcine retinal pigment epithelial cells, human retinal pigment epithelial cells, and fibroblast (3T3/NIH) cells, by electric cell-substrate impedance sensing system. Furthermore, the hydrogels did not impair tight junction formation or affect proliferation of the cells. The hydrogels were also non-degradable in enzymatic solutions and in contact with ocular cell line for four weeks. Judged against silicone oil, a clinically-accepted vitreous replacement, both hydrogel formulations were biocompatible in rabbits for 30 days. Both hydrogels maintained optical clarity, physiological intra-ocular pressure, and intact retinal layers that displayed normal electroretinographs. In two cases of the iatrogenic retinal tear, the hydrogels reattached the retina by producing osmotic swelling pressure. The hydrogels also maintained the low oxygen environment, compared to silicone oil, in the rabbit’s vitreous cavity for 30 days post-surgery.
In conclusion, the two hydrogels reattach the retina via a unique mechanism of osmotic swelling pressure. They overcome the limitations of silicone oil with comparable in-vivo biocompatibility, and merit further evaluations as an artificial vitreous. In addition, the ability to control the mechanical and swelling properties of the two-component hydrogels over a wide range suggests their utility as biomimetic replacements of other soft tissues, such as cornea, nucleus pulposus, and cartilage
MICE LACKING MIST1 SHOW INCREASED SENSITIVITY TO CHRONIC ETHANOL EXPOSURE
Rodent models show that alcohol only sensitizes the pancreas to subsequent insult, indicating that additional factors play a role in alcohol-induced pancreatic injury. Mice lacking MIST1 (Misti4\u27), a target of the UPR marker XBP1, show reduced ability to activate the UPR during cell stress. Therefore, I hypothesized that an absence of MIST1 would lead to increased sensitivity to alcohol feeding. The effects of dietary stress on the UPR were examined in pancreatic tissue from 2 to 4 month-old mice placed on a diet containing 36% of kcal from ethanol for 6 weeks. Based on immunofluorescent, histological and immunoblotting assays, MistTAmice showed age related changes in UPR activation. In response to ethanol, they developed periductal accumulations of inflammatory cells, limited induction of autophagy and reduction in the expression of BiP, pelF2a and sXbp1, unlike wild type counterparts that had significantly higher levels of sXbp1 and pelF2a. The UPR was not further activated following initiation of acute pancreatitis. This work suggests that factors affecting MIST1 expression and function in humans may be a predisposing factor for pancreatic disease
Hadoop Based Data Intensive Computation on IAAS Cloud Platforms
Cloud computing is a relatively new form of computing which uses virtualized resources. It is dynamically scalable and is often provided as pay for use service over the Internet or Intranet or both. With increasing demand for data storage in the cloud, the study of data-intensive applications is becoming a primary focus. Data intensive applications are those which involve high CPU usage, processing large volumes of data typically in size of hundreds of gigabytes, terabytes or petabytes. The research in this thesis is focused on the Amazon’s Elastic Cloud Compute (EC2) and Amazon Elastic Map Reduce (EMR) using HiBench Hadoop Benchmark suite. HiBench is a Hadoop benchmark suite and is used for performing and evaluating Hadoop based data intensive computation on both these cloud platforms. Both quantitative and qualitative comparisons of Amazon EC2 and Amazon EMR are presented. Also presented are their pricing models and suggestions for future research
Advanced laser frequency stabilisation systems for mobile strontium optical lattice clocks
Strontium optical lattice clocks have undergone vast developments in the past decade with world leading frequency stability and uncertainty records. Now, a lot of scientists are moving from laboratory based clocks to transportable, and portable clocks for applications including space, fundamental science, finance, and communication. The research team at the University of Birmingham are working towards developing transportable apparatus for studying fundamental physics, global positioning system (GPS), and geodesy applications. This thesis reports on the progress towards two different transportable strontium optical lattice clocks, which we will call ‘miniclock’ and ‘Space Optical lattice Clock 2’ (SOC2).
A diode-seeded tapered amplifier based narrow linewidth laser is developed and used to realise second stage cooling of strontium in miniclock apparatus. The laser has achieved a linewidth of 1 kHz after stabilising to a 3 cm long optical reference cavity. A multiple frequency stabilisation unit (FSU) for strontium lattice clocks is established. It is a robust, portable, and compact frequency stabilisation unit with a volume of 593 cm^3. Three different lasers are currently locked simultaneously to the FSU cavity, which could be extended to any number of lasers, enabling to use a single cavity for locking all the lasers required in a strontium lattice clock, except the clock laser. FSU is designed specifically for use in compact clocks. In the SOC2 system, realisation of clock transition and its characterisation are performed. A transition linewidth of 3 Hz is obtained for the SOC2 strontium clock. Further details and results are described in the thesis
Immunotherapeutic Strategies to Reverse Tumor Associated Immunosuppression in Breast Cancer
Heterogenous cancers such as breast carcinoma, would highly benefit from personalized vaccine approaches such as autologous tumor cell vaccines (ATCVs). By using cancer cells that are isolated from self, this approach has the potential to generate a polyclonal immune response against tumor antigens, that are specific to the individual. However, so far, ATCVs against breast cancers have not had any clinical success due to the poor immunogenicity of the malignant cells.
In this study, for the first time, we determined tumor derived G-CSF to play a major role in affecting immune response against breast cancer ATCVs. By using CRISPR/Cas9 genome editing technology, we found that tumor derived G-CSF results in the accumulation of exceptionally high levels of myeloid derived suppressor cells (MDSCs) in the spleen and lymph nodes of immunized mice. For the first time, we demonstrated that by eliminating G-CSF in ATCVs, the overall efficacy of the vaccine can be significantly improved. Further, for the first time, by using breast cancer cells that naturally produce varying levels of G-CSF, we reestablished the effect of G-CSF on splenic MDSC accumulation.
Additionally, we addressed the MDSC associated immunosuppression, by investigating strategies to facilitate the maturation of immature immune cells. We considered different commercially available toll like receptor (TLR) agonists namely Pam3CSK4 (Pam), Poly (I:C), lipopolysaccharide, FLA-ST, FSL-1 and R848, and compared their effect on MDSC maturation in-vitro. Of all the agonists, we found that only Pam resulted in the complete maturation of MDSCs since it resulted in the upregulation of all four MDSC maturation markers, CD80, CD86, MHCII and F4/80. Additionally, Pam also significantly reduced the number of MDSCs in the treated whole splenocyte cultures.
Future studies that are discussed here will expand our knowledge on the effect of tumor derived G-CSF in clinical cancer burden and metastasis of breast cancer. Further, in-vivo studies with the TLR agonists, would help design an effective adjuvant therapy against aggressive and metastatic breast cancers, with improved survival and reduced rate of recurrence
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