Scaling Law for the Cosmological Constant from Quantum Cosmology with Seven Extra Dimensions

According to a model of quantum cosmology the maximum number of degrees of freedom allowed in our three dimensions was determined by the size of seven extra dimensions in an initial excited state before inflation. The size of the extra dimensions can be inferred from a simple scheme for unifying the strong force and gravity. Coupled with the Bekenstein-Hawking entropy bound, these considerations lead to a scaling law for the cosmological constant that has been proposed independently by several authors.Comment: matches published version in IJT

Temperature-sensitive Tien Shan tree ring chronologies show multi-centennial growth trends

Two millennia-length juniper ring width chronologies, processed to preserve multi-centennial growth trends, are presented for the Alai Range of the western Tien Shan in Kirghizia. The chronologies average the information from seven near-timberline sampling sites, and likely reflect summer temperature variation. For comparison, chronologies are also built using standard dendrochronological techniques. We briefly discuss some qualities of these "inter-decadal” records, and show the low frequency components removed by the standardization process include a long-term negative trend in the first half of the last millennium and a long-term positive trend since about AD 1800. The multi-centennial scale Alai Range chronologies, where these trends are retained, are both systematically biased (but in an opposite sense) in their low frequency domains. Nevertheless, they represent the best constraints and estimates of long-term summer temperature variation, and reflect the Medieval Warm Period, the Little Ice Age, and a period of warming since about the middle of the nineteenth centur

A stem-cell-derived platform enables complete Cryptosporidium development in vitro and genetic tractability

Despite being a frequent cause of severe diarrheal disease in infants and an opportunistic infection in immunocompromised patients, Cryptosporidium research has lagged due to a lack of facile experimental methods. Here, we describe a platform for complete life cycle development and long-term growth of C. parvum in vitro using air-liquid interface (ALI) cultures derived from intestinal epithelial stem cells. Transcriptomic profiling revealed that differentiating epithelial cells grown under ALI conditions undergo profound changes in metabolism and development that enable completion of the parasite life cycle in vitro. ALI cultures support parasite expansion \u3e 100-fold and generate viable oocysts that are transmissible in vitro and to mice, causing infection and animal death. Transgenic parasite lines created using CRISPR/Cas9 were used to complete a genetic cross in vitro, demonstrating Mendelian segregation of chromosomes during meiosis. ALI culture provides an accessible model that will enable innovative studies into Cryptosporidium biology and host interactions

Integrated Vehicle-Based Safety System (IVBSS): Heavy truck extended pilot test summary report

This report describes the findings and recommendations from the heavy-truck (HT) extended pilot test (EPT) conducted by University of Michigan Transportation Research Institute (UMTRI) and its partners under the Integrated Vehicle-Based Safety Systems (IVBSS) program. The EPT was conducted to provide evidence of system performance (alert rate and reliable operation) and driver acceptance prior to conduct of the field operational test (FOT). The results of this test were to be used to modify the HT system performance and functionality as required, prior to the start of the FOT. The EPT entailed use of an integrated crash warning system in a heavy truck by seven drivers, over a period of five days each, in the course of their regular duties as drivers for Con-way Freight at the Ann Arbor distribution center. The test lasted four weeks starting on November 10 and ending December 12, 2008; the resultant data represent 5,300 miles of system use. The extended pilot test of the heavy truck platform on the IVBSS program successfully evaluated system performance and driver acceptance. Driver recruitment and training procedures were tested, as were the driver survey and debriefing methodologies. The warning system and data acquisition hardware operated reliably through the EPT. However, the warning system had an alert rate that was higher than anticipated based on previous testing. Nonetheless, drivers were generally still accepting of the system. Valuable data obtained from the EPT have led to further system performance improvements in the detection of stopped and slower-moving objects by the FCW subsystem in order to reduce the alert rate, and these enhancements have been implemented into the heavy truck fleet for the full field operational test.U.S. Department of Transportationhttp://deepblue.lib.umich.edu/bitstream/2027.42/62989/1/102284.pd

Playing it cool: Characterizing social play, bout termination, and candidate play signals of juvenile and infant Tibetan macaques (Macaca thibetana)

Play behaviors and signals during playful interactions with juvenile conspecifics are important for both the social and cognitive development of young animals. The social organization of a species can also influence juvenile social play. We examined the relationships among play behaviors, candidate play signals, and play bout termination in Tibetan macaques (Macaca thibetana) during juvenile and infant social play to characterize the species play style. As Tibetan macaques are despotic and live in groups with strict linear dominance hierarchies and infrequent reconciliation, we predicted that play would be at risk of misinterpretation by both the individuals engaged in the play bout and by those watching, possibly leading to injury of the players. Animals living in such societies might need to frequently and clearly signal playful intent to play partners and other group members to avoid aggressive outcomes. We gathered video data on 21 individually-identified juvenile and infant macaques (one month to five years of age) from the Valley of the Wild Monkeys, Mt. Huangshan, China. We used all-occurrence sampling to record play behaviors and candidate play signals based on an ethogram. We predicted that play groups would use multiple candidate play signals in a variety of contexts and in association with the number of audience members in proximity to the players and play bout length. In the 283 playful interactions we scored, juvenile and infant macaques used multiple body and facial candidate play signals. Our data showed that juvenile and infant Tibetan macaques use a versatile repertoire of play behaviors and signals to sustain play

Molecular Beams

Contains reports on five research projects

Neonatal mouse gut metabolites influence Cryptosporidium parvum infection in intestinal epithelial cells

The protozoan parasit