Experimental tests of pseudo-complex General Relativity

Based on previous publications exploring pseudo-complex General Relativity (pc-GR) we present a selection of observable consequences of pc-GR and possible ways to experimentally access them. Whenever possible we compare the results to Einstein's GR and differences are worked out in detail. We propose experimental tests to check the predictions of pc-GR for the orbital frequency of test particles, the gravitational redshift effect and the last stable orbit. We will show that the orbital frequency of test particles at a given radius in pc-GR is in general lower compared to standard GR. Also the effect of frame dragging is modified (weakened) in pc-GR. Concerning the gravitational redshift of a radiation emitting object we find that it is also lower in pc-GR than in standard GR. Eventually the classical concept of a last stable orbit has to be modified in pc-GR.Comment: submitted for publication to the Monthly Notices of the Royal Astronomical Societ

Do Childhood Vaccines Have Non-Specific Effects on Mortality

A recent article by Kristensen et al. suggested that measles vaccine and bacille Calmette–Guérin (BCG) vaccine might\ud reduce mortality beyond what is expected simply from protection against measles and tuberculosis. Previous reviews of the potential effects of childhood vaccines on mortality have not considered methodological features of reviewed studies. Methodological considerations play an especially important role in observational assessments, in which selection factors for vaccination may be difficult to ascertain. We reviewed 782 English language articles on vaccines and childhood mortality and found only a few whose design met the criteria for methodological rigor. The data reviewed suggest that measles vaccine delivers its promised reduction in mortality, but there is insufficient evidence to suggest a mortality benefit above that caused by its effect on measles disease and its sequelae. Our review of the available data in the literature reinforces how difficult answering these considerations has been and how important study design will be in determining the effect of specific vaccines on all-cause mortality.\u

A Stochastic Model of Cell Cycle Desynchronization

A general branching process model is suggested to describe cell cycle desynchronization. Cell cycle phase times are modeled as random variables and a formula for the expected fraction of cells in S phase as a function of time is established. The model is compared to data from the literature and is also compared to previously suggested deterministic and stochastic models

Electronic cigarettes and nicotine dependence: evolving products, evolving problems

Electronic cigarettes (ECIGs) use an electric heater to aerosolize a liquid that usually contains propylene glycol, vegetable glycerin, flavorants, and the dependence-producing drug nicotine. ECIG-induced nicotine dependence has become an important concern, as some ECIGs deliver very little nicotine while some may exceed the nicotine delivery profile of a tobacco cigarette. This variability is relevant to tobacco cigarette smokers who try to switch to ECIGs. Products with very low nicotine delivery may not substitute for tobacco cigarettes, so that ECIG use is accompanied by little reduced risk of cigarette-caused disease. Products with very high nicotine delivery may make quitting ECIGs particularly difficult should users decide to try. For non-smokers, the wide variability of ECIGs on the market is especially troublesome: low nicotine products may lead them to initiate nicotine self-administration and progress to higher dosing ECIGs or other products, and those that deliver more nicotine may produce nicotine dependence where it was not otherwise present. External regulatory action, guided by strong science, may be required to ensure that population-level nicotine dependence does not rise

Electronic cigarettes and nicotine dependence: evolving products, evolving problems

Electronic cigarettes (ECIGs) use an electric heater to aerosolize a liquid that usually contains propylene glycol, vegetable glycerin, flavorants, and the dependence-producing drug nicotine. ECIG-induced nicotine dependence has become an important concern, as some ECIGs deliver very little nicotine while some may exceed the nicotine delivery profile of a tobacco cigarette. This variability is relevant to tobacco cigarette smokers who try to switch to ECIGs. Products with very low nicotine delivery may not substitute for tobacco cigarettes, so that ECIG use is accompanied by little reduced risk of cigarette-caused disease. Products with very high nicotine delivery may make quitting ECIGs particularly difficult should users decide to try. For non-smokers, the wide variability of ECIGs on the market is especially troublesome: low nicotine products may lead them to initiate nicotine self-administration and progress to higher dosing ECIGs or other products, and those that deliver more nicotine may produce nicotine dependence where it was not otherwise present. External regulatory action, guided by strong science, may be required to ensure that population-level nicotine dependence does not rise

Novel treatment strategies for chronic kidney disease: insights from the animal kingdom

Many of the >2 million animal species that inhabit Earth have developed survival mechanisms that aid in the prevention of obesity, kidney disease, starvation, dehydration and vascular ageing; however, some animals remain susceptible to these complications. Domestic and captive wild felids, for example, show susceptibility to chronic kidney disease (CKD), potentially linked to the high protein intake of these animals. By contrast, naked mole rats are a model of longevity and are protected from extreme environmental conditions through mechanisms that provide resistance to oxidative stress. Biomimetic studies suggest that the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) offers protection in extreme environmental conditions and promotes longevity in the animal kingdom. Similarly, during months of fasting, immobilization and anuria, hibernating bears are protected from muscle wasting, azotaemia, thrombotic complications, organ damage and osteoporosis - features that are often associated with CKD. Improved understanding of the susceptibility and protective mechanisms of these animals and others could provide insights into novel strategies to prevent and treat several human diseases, such as CKD and ageing-associated complications. An integrated collaboration between nephrologists and experts from other fields, such as veterinarians, zoologists, biologists, anthropologists and ecologists, could introduce a novel approach for improving human health and help nephrologists to find novel treatment strategies for CKD

Prelaunch optical characterization of the Laser Geodynamic Satellite (LAGEOS 2)

The optical range correction (the distance between the apparent retroreflective skin of the satellite and the center of mass) of the LAGEOS 2 was determined using computer analysis of theoretical and experimentally measured far field diffraction patterns, and with short pulse lasers using both streak camera-based range receivers and more conventional PMT-based range receivers. The three measurement techniques yielded range correction values from 248 to 253 millimeters dependent on laser wavelength, pulsewidth, and polarization, location of the receiver in the far field diffraction pattern and detection technique (peak, half maximum, centroid, or constant fraction). The Lidar cross section of LAGEOS 2 was measured at 4 to 10 million square meters, comparable to the LAGEOS 1

TPC-H Analyzed: Hidden Messages and Lessons Learned from an Influential Benchmark

The TPC-D benchmark was developed almost 20 years ago, and even though its current existence as TPC H could be considered superseded by TPC-DS, one can still learn from it. We focus on the technical level, summarizing the challenges posed by the TPC-H workload as we now understand them, which w