Teleporters, tunnels & time : Understanding warp devices in videogames

Catchment land uses, particularly agriculture and urban uses, have long been recognized as major drivers of nutrient concentrations in surface waters. However, few simple models have been developed that relate the amount of catchment land use to downstream freshwater nutrients. Nor are existing models applicable to large numbers of freshwaters across broad spatial extents such as regions or continents. This research aims to increase model performance by exploring three factors that affect the relationship between land use and downstream nutrients in freshwater: the spatial extent for measuring land use, hydrologic connectivity, and the regional differences in both the amount of nutrients and effects of land use on them. We quantified the effects of these three factors that relate land use to lake total phosphorus (TP) and total nitrogen (TN) in 346 north temperate lakes in 7 regions in Michigan, USA. We used a linear mixed modeling framework to examine the importance of spatial extent, lake hydrologic class, and region on models with individual lake nutrients as the response variable, and individual land use types as the predictor variables. Our modeling approach was chosen to avoid problems of multi-collinearity among predictor variables and a lack of independence of lakes within regions, both of which are common problems in broad-scale analyses of freshwaters. We found that all three factors influence land use-lake nutrient relationships. The strongest evidence was for the effect of lake hydrologic connectivity, followed by region, and finally, the spatial extent of land use measurements. Incorporating these three factors into relatively simple models of land use effects on lake nutrients should help to improve predictions and understanding of land use-lake nutrient interactions at broad scales

Identification of an alternating-access dynamics mutant of EmrE with impaired transport

Proteins that perform active transport must alternate the access of a binding site, first to one side of a membrane and then to the other, resulting in the transport of bound substrates across the membrane. To better understand this process, we sought to identify mutants of the small multidrug resistance transporter EmrE with reduced rates of alternating access. We performed extensive scanning mutagenesis by changing every amino acid residue to Val, Ala, or Gly, and then screening the drug resistance phenotypes of the resulting mutants. We identified EmrE mutants that had impaired transport activity but retained the ability to bind substrate and further tested their alternating access rates using NMR. Ultimately, we were able to identify a single mutation, S64V, which significantly reduced the rate of alternating access but did not impair substrate binding. Six other transport-impaired mutants did not have reduced alternating access rates, highlighting the importance of other aspects of the transport cycle to achieve drug resistance activity in vivo. To better understand the transport cycle of EmrE, efforts are now underway to determine a high-resolution structure using the S64V mutant identified here

Descriptive and Substantive Representation in Congress: Evidence from 80,000 Congressional Inquiries

A vast literature debates the efficacy of descriptive representation in legislatures. Though studies argue it influences how communities are represented through constituency service, they are limited since legislators’ service activities are unobserved. Using Freedom of Information Act (FOIA) requests, we collected 88,000 records of communication between members of the U.S. Congress and federal agencies during the 108th–113th Congresses. These legislative interventions allow us to examine members’ “follow‐through” with policy implementation. We find that women, racial/ethnic minorities, and veterans are more likely to work on behalf of constituents with whom they share identities. Including veterans offers leverage in understanding the role of political cleavages and shared experiences. Our findings suggest that shared experiences operate as a critical mechanism for representation, that a lack of political consensus is not necessary for substantive representation, and that the causal relationships identified by experimental work have observable implications in the daily work of Congress.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150606/1/ajps12443-sup-0001-SuppMat.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150606/2/ajps12443.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150606/3/ajps12443_am.pd

Signs of Humanity: A Qualitative Exploration of Panhandling in Philadelphia

People who participate in panhandling are those who ask for financial or other assistance on the street. In Philadelphia, it is known that a large portion of people who panhandle also experience housing insecurity or other hardship. Panhandlers are a very visible fraction of a city’s homeless population and their experiences are of particular interest because their cardboard signs can give insight into common hardships such as housing and food insecurity and substance abuse disorders. While panhandlers in Philadelphia have been surveyed in the past, there is not recent literature on their lived experiences and perspectives and information was not collected and analyzed in a qualitative manner. The purpose of this study was to shed light on the experiences and needs of those who panhandle in Philadelphia. This was a qualitative study that utilized open-ended and freelisting questions. The results of the open ended questions will be analyzed via thematic coding. This approach will highlight major themes in responses to allow summary and organization of the major findings. Analysis of the freelisting question specifically will give information about the ways that those who participate in panhandling spend the money they receive. Formal results are pending, but preliminary findings reveal appreciation of social interaction with passersby, explanations for IV drug use, and lack of family and social support among study participants.The final results will guide recommendations on initiatives benefiting Philadelphia’s homeless population

Molecules incorporating a benzothiazole core scaffold inhibit the N-myristoyltransferase of Plasmodium falciparum.

Recombinant N-myristoyltransferase of Plasmodium falciparum (termed PfNMT) has been used in the development of a SPA (scintillation proximity assay) suitable for automation and high-throughput screening of inhibitors against this enzyme. The ability to use the SPA has been facilitated by development of an expression and purification system which yields considerably improved quantities of soluble active recombinant PfNMT compared with previous studies. Specifically, yields of pure protein have been increased from 12 microg x l(-1) to >400 microg x l(-1) by use of a synthetic gene with codon usage optimized for expression in an Escherichia coli host. Preliminary small-scale 'piggyback' inhibitor studies using the SPA have identified a family of related molecules containing a core benzothiazole scaffold with IC50 values 80% at a concentration of 10 microM

The 17th Dynasty gold necklace from Qurneh, Egypt

In 1908, the archaeologist Flinders Petrie discovered a rich intact burial of an adult and child at Qurneh, near Luxor. Stylistically, the burial has been dated to the late 17th Dynasty, in the 16th century BC. The complete burial group came to Edinburgh in 1909. A recent examination of the rings of the necklace found with the adult burial is presented as part of a wider study of the mummy collections of the National Museums Scotland (NMS). The necklace shows sophisticated workmanship, with 1,699 rings threaded onto four strands, the rings having uniform diameter and thickness, and very few of them showing any visible joints. The necklace rings have been examined by Optical Microscopy, X-radiography, Scanning Electron Microscopy with Energy Dispersive X-ray analysis (SEM-EDS), air-path X-ray Fluorescence (XRF), and proton induced X-ray analysis (micro-PIXE). We summarise these findings and propose the method of manufacture. We also describe an experimental attempt to make joint-less rings in order to compare them with the originals.En 1908, l’archéologue Flinders Petrie découvre à Qurneh, près de Louxor, sur la route de la Vallée des Rois, la tombe intacte et richement pourvue d’un adulte et d’un enfant. L’ensemble de la tombe a été stylistiquement daté de la fin de la XVIIe dynastie, xvie siècle av. J.-C., et son contenu fut transféré à Edimbourg en 1909. Dans le cadre d’un projet de recherche sur la collection des momies égyptiennes du Musée National d’Écosse (NMS), le collier trouvé associé à l’adulte a été étudié. Ce collier se compose de 1 699 anneaux enfilés sur quatre rangs, chaque anneau présentant une section circulaire très uniforme avec très peu de joints apparents. Comment ses anneaux ont-ils été réalisés ? Le collier a été analysé par microscopie optique, radiographie de rayons X, Microscopie Électronique à Balayage couplée à un système d’énergie dispersive de rayons X (MEB-EDS), Fluorescence de rayons X (FX) et analyse par faisceaux d’ions (micro-PIXE). Les résultats de cette étude sont présentés et discutés en parallèle avec les résultats d’un travail de recréation expérimental, visant à réaliser des anneaux sans joints apparents