Collagen-hyaluronic acid scaffolds for adipose tissue engineering.

Three-dimensional (3-D) in vitro models of the mammary gland require a scaffold matrix that supports the development of adipose stroma within a robust freely permeable matrix. 3-D porous collagen-hyaluronic acid (HA: 7.5% and 15%) scaffolds were produced by controlled freeze-drying technique and crosslinking with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride. All scaffolds displayed uniform, interconnected pore structure (total porosity approximately 85%). Physical and chemical analysis showed no signs of collagen denaturation during the formation process. The values of thermal characteristics indicated that crosslinking occurred and that its efficiency was enhanced by the presence of HA. Although the crosslinking reduced the swelling of the strut material in water, the collagen-HA matrix as a whole tended to swell more and show higher dissolution resistance than pure collagen samples. The compressive modulus and elastic collapse stress were higher for collagen-HA composites. All the scaffolds were shown to support the proliferation and differentiation 3T3-L1 preadipocytes while collagen-HA samples maintained a significantly increased proportion of cycling cells (Ki-67+). Furthermore, collagen-HA composites displayed significantly raised Adipsin gene expression with adipogenic culture supplementation for 8 days vs. control conditions. These results indicate that collagen-HA scaffolds may offer robust, freely permeable 3-D matrices that enhance mammary stromal tissue development in vitro.This was supported by the Biotechnology and Biological Sciences Research Council

Are the dead taking over Facebook? A Big Data approach to the future of death online

We project the future accumulation of profiles belonging to deceased Facebook users. Our analysis suggests that a minimum of 1.4 billion users will pass away before 2100 if Facebook ceases to attract new users as of 2018. If the network continues expanding at current rates, however, this number will exceed 4.9 billion. In both cases, a majority of the profiles will belong to non-Western users. In discussing our findings, we draw on the emerging scholarship on digital preservation and stress the challenges arising from curating the profiles of the deceased. We argue that an exclusively commercial approach to data preservation poses important ethical and political risks that demand urgent consideration. We call for a scalable, sustainable, and dignified curation model that incorporates the interests of multiple stakeholders

Mammary Stem Cells: Premise, Properties, and Perspectives

Adult mammary stem cells (MaSCs) drive postnatal organogenesis and remodeling in the mammary gland, and their longevity and potential have important implications for breast cancer. However, despite intense investigation the identity, location, and differentiation potential of MaSCs remain subject to deliberation. The application of genetic lineage-tracing models, combined with quantitative 3D imaging and biophysical methods, has provided new insights into the mammary epithelial hierarchy that challenge classical definitions of MaSC potency and behaviors. We review here recent advances - discussing fundamental unresolved properties of MaSC potency, dynamics, and plasticity - and point to evolving technologies that promise to shed new light on this intractable debate. Elucidation of the physiological mammary differentiation hierarchy is paramount to understanding the complex heterogeneous breast cancer landscape.his work was supported by the Medical Research Council ( MR/J001023/1 to C.J.W. and B.L-L.), the Wellcome Trust ( 105377/Z/14/Z to O.B.H.), the National Health and Medical Research Council ( 1071074 to F.M.D.), and a University of Queensland Early Career Researcher Grant ( UQECR1718865 to F.M.D.)

Development of three-dimensional collagen scaffolds with controlled architecture for cell migration studies using breast cancer cell lines

Cancer is characterized by cell heterogeneity and the development of 3D $\textit{in vitro }$ assays that can distinguish more invasive or migratory phenotypes could enhance diagnosis or drug discovery. 3D collagen scaffolds have been used to develop analogues of complex tissues $\textit{in vitro }$ and are suited to routine biochemical and immunological assays. We sought to increase 3D model tractability and modulate the migration rate of seeded cells using an ice-templating technique to create either directional/anisotropic or non-directional/isotropic porous architectures within cross-linked collagen scaffolds. Anisotropic scaffolds supported the enhanced migration of an invasive breast cancer cell line MDA-MB-231 with an altered spatial distribution of proliferative cells in contrast to invasive MDA-MB-468 and non-invasive MCF-7 cells lines. In addition, MDA-MB-468 showed increased migration upon epithelial-to-mesenchymal transition (EMT) in anisotropic scaffolds. The provision of controlled architecture in this system may act both to increase assay robustness and as a tuneable parameter to capture detection of a migrated population within a set time, with consequences for primary tumour migration analysis. The separation of invasive clones from a cancer biomass with in vitro platforms could enhance drug development and diagnosis testing by contributing assay metrics including migration rate, as well as modelling cell-cell and cell-matrix interaction in a system compatible with routine histopathological testing.The authors gratefully acknowledge the financial support of the ERC Advanced Grant 320598 3D-E and the Newton Trust. A.H. held a Daphne Jackson Fellowship funded by the University of Cambridge for part of the work. R.D.H. is funded through a NC3Rs studentship

Statistics education at a time of global disruption and crises: a growing challenge for the curriculum, classroom and beyond

COVID-19 provided the world at large, including the world of mathematics education, with a challenge demanding attention and understanding. If met, this could potentially provide society with many of the skills needed to tackle the challenges of hyperobjects (Morton, 2013) such as climate change, which are potentially more threatening in the long-term. The COVID-19 context and the massive amount of data it has produced are the most recent examples of the growing recognition that the school mathematics curriculum has a role to play outside of the pure mathematics classroom. This paper considers COVID-19 as a stimulus for increasing the importance of statistical literacy and data literacy in preparing society for coping with world crises. Topics considered include the importance of acknowledging statistics as a significant component of mathematical ways of knowing, the contextual motivation provided by the COVID-19 crisis, the importance of statistics and statistical literacy, the place of statistics in the wider school curriculum, and finally, its place in the classroom. These topics need to be taken into account by both policy makers and teachers

Detecting grave sites from surface anomalies: A longitudinal study in an Australian woodland.

Forensic investigations of single and mass graves often use surface anomalies, including changes to soil and vegetation conditions, to identify potential grave locations. Though numerous resources describe surface anomalies in grave detection, few studies formally investigate the rate at which the surface anomalies return to a natural state; hence, the period the grave is detectable to observers. Understanding these processes can provide guidance as to when ground searches will be an effective strategy for locating graves. We studied three experimental graves and control plots in woodland at the Australian Facility for Taphonomic Experimental Research (Sydney, Australia) to monitor the rate at which surface anomalies change following disturbance. After three years, vegetation cover on all grave sites and control plots had steadily increased but remained substantially less than undisturbed surroundings. Soil anomalies (depressions and cracking) were more pronounced at larger grave sites versus the smaller grave and controls, with leaf litterfall rendering smaller graves difficult to detect beyond 20 months. Similar results were observed in two concurrent burial studies, except where accelerated revegetation appeared to be influenced by mummified remains. Extreme weather events such as heatwaves and heavy rainfall may prolong the detection window for grave sites by hindering vegetation establishment. Observation of grave-indicator vegetation, which exhibited abnormally strong growth 10 months after commencement, suggests that different surface anomalies may have different detection windows. Our findings are environment-specific, but the concepts are applicable globally