694 research outputs found
Ancient Organic Residues as Cultural and Environmental Proxies: The Value of Legacy Objects
Often treated as an accessory science, organic residue analysis (ORA) has the capacity to illuminate otherwise hidden aspects of ancient technology, culture, and economy, and therein can play a central role in archaeological inquiry. Through ORA, both the intact vessel freshly excavated from a tomb and the sherd tucked away in a museum storage closet can offer insights into their contents, their histories, and the cultures that created them—provided the results can be carefully calibrated to account for their treatment during and after excavation. The case study below presents ORA data obtained from a range of artifacts from Late Bronze Age Crete, setting results from freshly-excavated and legacy objects alongside one another. Although legacy objects do tend to yield diminished results from both a quantitative and qualitative perspective, our comparative work has demonstrated both their value and untapped potential when their object biographies are carefully considered. It also sheds light on biomarker degradation processes, which have implications for methodologies of extraction and interpretation of legacy objects. Comparative studies such as these broaden the pool of viable ORA candidates, and therein amplify ORA’s ability to reveal patterns of consumption as well as ecological and environmental change. They also highlight the role and value of data-sharing in collaborative environments such as the OpenARCHEM archaeometric database. Keywords: organic residue analysis (ORA); archaeochemistry; phytochemistry; ethnobotany; ethnohistory; paleoenvironment; paleoecology; legacy artifacts; perfumed oils; Minoan Crete; OpenARCHE
LPP3 mediates self-generation of chemotactic LPA gradients by melanoma cells
Melanoma cells steer out of tumours using self-generated lysophosphatidic acid (LPA) gradients. The cells break down LPA, which is present at high levels around the tumours, creating a dynamic gradient that is low in the tumour and high outside. They then also migrate up this gradient, creating a complex and evolving outward chemotactic stimulus. Here we introduce a new assay for self-generated chemotaxis, and show that raising LPA levels causes a delay in migration rather than loss of chemotactic efficiency. Knockdown of the lipid phosphatase LPP3 - but not its homologues LPP1 or LPP2 - diminishes the cell's ability to break down LPA. This is specific for chemotactically active LPAs, such as the 18:1 and 20:4 species. Inhibition of autotaxin-mediated LPA production does not diminish outward chemotaxis, but loss of LPP3-mediated LPA breakdown blocks it. Similarly, in both 2D and 3D invasion assays, knockdown of LPP3 diminishes melanoma cells' ability to invade. Our results demonstrate that LPP3 is the key enzyme in melanoma cells' breakdown of LPA, and confirm the importance of attractant breakdown in LPA-mediated cell steering
Mapping lightning in the sky with a mini array
Mini arrays are commonly used for infrasonic and seismic studies. Here we report for the first time the detection and mapping of distant lightning discharges in the sky with a mini array. The array has a baseline to wavelength ratio ∼4.2·10−2 to record very low frequency electromagnetic waves from 2 to 18 kHz. It is found that the mini array detects ∼69 lightning pulses per second from cloud-to-ground and in-cloud discharges, even though the parent thunderstorms are ∼900–1100 km away and a rigorous selection criterion based on the quality of the wavefront across the array is used. In particular, lightning pulses that exhibit a clockwise phase progression are found at larger elevation angles in the sky as the result of a birefringent subionospheric wave propagation attributed to ordinary and extraordinary waves. These results imply that long range lightning detection networks might benefit from an exploration of the wave propagation conditions with mini arrays.</p
Overcoming the barriers to implementing urban road user charging schemes
Urban road user charging offers the potential to achieve significant improvements in urban transport, but is notoriously difficult to implement. Cities need guidance on the range of factors to be considered in planning and implementing such schemes. This paper summarises the results of a 3 year programme which has collated evidence on the issues of most concern to cities. A state of the art report has provided evidence on 14 themes, ranging from objectives and design to implementation and evaluation. A set of 16 case studies has reviewed experience in design and implementation across Europe. The paper summarises their findings, provides references to more detailed information, presents the resulting policy recommendations to European, national and local government, and outlines the areas in which further research is needed
A new graft insertion device for descemet stripping automated endothelial keratoplasty
Purpose: Corneal endothelial dysfunction is a major indicator for corneal graft surgery worldwide, and whilst surgical intervention via a range of posterior lamellar surgeries has proven to be hugely beneficial, challenges remain. This is especially so where the anterior chamber is relatively shallow, as is often the case in the Asian population, though not exclusively so. Here, we introduce a new insertion device to deliver endothelial graft tissue for Descemet stripping automated endothelial keratoplasty (DSAEK).
Methods: A new surgical tool was designed and manufactured so as to enable a one-step insertion of corneal graft tissue into the anterior chamber based on a pressure-flow concept, rather than the a pull-through one. This was tested ex vivo to assess endothelial cell damage, then performed in 12 first-in-man surgeries.
Results: Pre-cut DSAEK lenticules implanted in donor corneas ex vivo via the new technique showed less endothelial cell damage occurs compared to a pull-through technique. Grafts were successful in all patients receiving the new surgery, with no cases of primary graft failure.
Conclusion: The newly developed DSAEK inserter is a simple and useful tool for endothelial graft delivery, lessening intraoperative mechanical stress on the graft tissue
Explaining Myanmar's Regime Transition: The Periphery is Central
In 2010, Myanmar (Burma) held its first elections after 22 years of direct military rule. Few compelling explanations for this regime transition have emerged. This article critiques popular accounts and potential explanations generated by theories of authoritarian ‘regime breakdown’ and ‘regime maintenance’. It returns instead to the classical literature on military intervention and withdrawal. Military regimes, when not terminated by internal factionalism or external unrest, typically liberalise once they feel they have sufficiently addressed the crises that prompted their seizure of power. This was the case in Myanmar. The military intervened for fear that political unrest and ethnic-minority separatist insurgencies would destroy Myanmar’s always-fragile territorial integrity and sovereignty. Far from suddenly liberalising in 2010, the regime sought to create a ‘disciplined democracy’ to safeguard its preferred social and political order twice before, but was thwarted by societal opposition. Its success in 2010 stemmed from a strategy of coercive state-building and economic incorporation via ‘ceasefire capitalism’, which weakened and co-opted much of the opposition. Having altered the balance of forces in its favour, the regime felt sufficiently confident to impose its preferred settlement. However, the transition neither reflected total ‘victory’ for the military nor secured a genuine or lasting peace
Synergies for Improving Oil Palm Production and Forest Conservation in Floodplain Landscapes
Lowland tropical forests are increasingly threatened with conversion to oil palm as global demand and high profit drives crop expansion throughout the world’s tropical regions. Yet, landscapes are not homogeneous and regional constraints dictate land suitability for this crop. We conducted a regional study to investigate spatial and economic components of forest conversion to oil palm within a tropical floodplain in the Lower Kinabatangan, Sabah, Malaysian Borneo. The Kinabatangan ecosystem harbours significant biodiversity with globally threatened species but has suffered forest loss and fragmentation. We mapped the oil palm and forested landscapes (using object-based-image analysis, classification and regression tree analysis and on-screen digitising of high-resolution imagery) and undertook economic modelling. Within the study region (520,269 ha), 250,617 ha is cultivated with oil palm with 77% having high Net-Present-Value (NPV) estimates (637/ha?yr); but 20.5% is under-producing. In fact 6.3% (15,810 ha) of oil palm is commercially redundant (with negative NPV of -65/ha?yr) due to palm mortality from flood inundation. These areas would have been important riparian or flooded forest types. Moreover, 30,173 ha of unprotected forest remain and despite its value for connectivity and biodiversity 64% is allocated for future oil palm. However, we estimate that at minimum 54% of these forests are unsuitable for this crop due to inundation events. If conversion to oil palm occurs, we predict a further 16,207 ha will become commercially redundant. This means that over 32,000 ha of forest within the floodplain would have been converted for little or no financial gain yet with significant cost to the ecosystem. Our findings have globally relevant implications for similar floodplain landscapes undergoing forest transformation to agriculture such as oil palm. Understanding landscape level constraints to this crop, and transferring these into policy and practice, may provide conservation and economic opportunities within these seemingly high opportunity cost landscapes
The Student Movement Volume 107 Issue 18: Ain\u27t I A Woman? : AU Students Reflect on the Feminist Movement
HUMANS
Interview with the WEAAU President, Interviewed by: Grace No
What is Feminism to You?, Interviewed by: Caryn Cruz
What\u27s Your Major?, Interviewed by: Nora Martin
ARTS & ENTERTAINMENT
Currently: The Idol, Solana Campbell
Faculty Art Exhibition, Ysabelle Fernando
Music Seniors: A Day in the Life, Aiko J. Ayala Rios
Through the Paintings, Kaela McFadden
NEWS
Empowering our Neighbors: Interview with H.E.L.P. Program Director Carlisle Suttton, Isabella Koh
John Wesley Taylor V Elected to be the Next Andrews University President
Students Open the Month with Cultural Showcase, Andrew Francis
The Agora at AU: A Conversation on Police Brutality, Solana Campbell
What\u27s Going on East Palestine, Ohio?, Julia Randall
IDEAS
The Biblical Bechdel: How Much are Women Represented in the Bible?, Bella Hamann
The Murder of Abby Choi: A Spotlight on Relationship Violence Against Women, Abby Shim
PULSE
Nilah Mataafa: An End to Period Poverty, Interviewed by: Chris Ngugi
Remember the Ladies! : The Female Perspective on Women\u27s History Month, Amelia Stefanescu
The Aerial Workout You\u27ve Never Heard Of, Melissa Moore
LAST WORD
Perfect Imperfections, Shania Wattshttps://digitalcommons.andrews.edu/sm-107/1017/thumbnail.jp
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