Identification of the growth arrest and DNA damage protein GADD34 in the normal human heart and demonstration of alterations in expression following myocardial ischaemia

Growth arrest and DNA damage protein 34 (GADD34) is a multifunctional protein upregulated in response to cellular stress and is believed to mediate DNA repair and restore protein synthesis. In the present study we have examined GADD34 immunoreactivity in human myocardial tissue at defined survival times following cardiac arrest and determined alterations in expression following ischaemia. In the normal human heart, GADD34 immunoreactivity was generally intense and present within most cells. GADD34 immunoreactivity was downregulated in tissue displaying ischaemic damage and remained intense in adjacent non-infarcted tissue. Unlike brain, GADD34 was not found to be upregulated in the peri-infarct zone. Cells displaying apoptotic changes were located in regions displaying reduced GADD34 immunoreactivity. In the brain, it is thought that GADD34 supports re-initiation of protein synthesis following ischaemia. Similarly, GADD34 may perform important functions in cardiac tissue in response to ischaemia

Physical limitations on quantum nonlocality in the detection of gamma photons emitted from positron/electron annihilation

Recent experimental measurements of the time interval between detection of the two photons emitted in positron/electron annihilation have indicated that collapse of the spatial part of the photon's wavefunction, due to detection of the other photon, does not occur. Although quantum nonlocality actually occurs in photons produced through parametric down-conversion, the recent experiments give strong evidence against measurement-induced instantaneous spatial-localization of high-energy gamma photons. A new quantum-mechanical analysis of the EPR problem is presented which may help to explain the observed differences between photons produced through parametric down-conversion and photons produced through positron/electron annihilation. The results are found to concur with the recent experiments involving gamma photons.Comment: accepted for publication, Phys. Rev.

The Solar--Stellar Connection

Stars have proven to be surprisingly prolific radio sources and the added sensitivity of the Square Kilometer Array will lead to advances in many directions. This chapter discusses prospects for studying the physics of stellar atmospheres and stellar winds across the HR diagram.Comment: to appear in "Science with the Square Kilometer Array," eds. C. Carilli and S. Rawlings, New Astronomy Reviews (Elsevier: Amsterdam

Modeling energy and reproductive costs in caribou exposed to low flying military jet aircraft

We used simulation modeling to estimate the effect of low-flying military jet aircraft on the productivity of caribou. The base model (CARIBOU, CWS Whitehorse, Yukon Territory) uses daily intake and expenditure of energy to assess the condition of female caribou throughout the annual cycle. The activity budget of the model caribou was adjusted based on field observations of responses to noise disturbance. A subroutine was added that predicted the likelihood of conception based on fall body fat weight. Caribou responses to overflights were evaluated by equipping free-ranging caribou with radio collars and activity sensors that could distinguish between resting and active periods. Collared animals were exposed to 110 overflights by A-10, F-15 and F- 16 jet aircraft during late-winter, post-calving and the insect season. Noise exposure levels for individual animals either were measured directly with collar-mounted dosimeters or were estimated based on the proximity of the caribou to the aircraft during the overflight. A Time-averaged Sound Level (LT) was calculated from the total daily noise exposure for each animal and linear regression was used to evaluate the influence of daily noise exposure on daily hours spent resting. Results of these analyses then were used to modify the time budgets in the CARIBOU model. That is, if time spent resting declined, then time spent in the two rest classes (lying and standing) were proportionately redistributed into the three active classes (foraging, walking and running). Model simulations indicated that caribou increased forage intake in response to increased noise exposure, but it also predicted that increased noise exposure would cause a reduced accumulation of body fat. Because body fat in fall has successfully been used to predict the probability of pregnancy (see Gerhart et al, 1993), this relationship was used in the model. Preliminary model simulations indicate that increased noise exposure decreases the probability of pregnancy and that unfavorable environmental conditions (e.g., deep snow and severe insect harassment) exacerbate the situation. The threshold at which point the caribou fail to conceive has not been determined at this time, but appears to be well beyond the exposure to aircraft that caribou in the Delta herd are currently experiencing

Tracking and Tolerances Study for the ATLAS High Beta Optics

International audienc

Modelling the effect of temperature on the seasonal population dynamics of temperate mosquitoes

Mosquito-borne diseases cause substantial mortality and morbidity worldwide. These impacts are widely predicted to increase as temperatures warm and extreme precipitation events become more frequent, since mosquito biology and disease ecology are strongly linked to environmental conditions. However, direct evidence linking environmental change to changes in mosquito-borne disease is rare, and the ecological mechanisms that may underpin such changes are poorly understood. Environmental drivers, such as temperature, can have non-linear, opposing impacts on the demographic rates of different mosquito life cycle stages. As such, model frameworks that can deal with fluctuations in temperature explicitly are required to predict seasonal mosquito abundance, on which the intensity and persistence of disease transmission under different environmental scenarios depends. We present a novel, temperature-dependent, delay-differential equation model, which incorporates diapause and the differential effects of temperature on the duration and mortality of each life stage and demonstrates the sensitivity of seasonal abundance patterns to inter- and intra-annual changes in temperature. Likely changes in seasonal abundance and exposure to mosquitoes under projected changes in UK temperatures are presented, showing an increase in peak vector abundance with warming that potentially increases the risk of disease outbreaks

Seismic data reveal eastern Black Sea Basin structure

Rifted continental margins are formed by progressive extension of the lithosphere. The development of these margins plays an integral role in the plate tectonic cycle, and an understanding of the extensional process underpins much hydrocarbon exploration. A key issue is whether the lithosphere extends uniformly, or whether extension varies\ud with depth. Crustal extension may be determined using seismic techniques. Lithospheric extension may be inferred from the waterloaded subsidence history, determined from\ud the pattern of sedimentation during and after rifting. Unfortunately, however, many rifted margins are sediment-starved, so the subsidence history is poorly known.\ud To test whether extension varies between the crust and the mantle, a major seismic experiment was conducted in February–March 2005 in the eastern Black Sea Basin (Figure 1), a deep basin where the subsidence history is recorded\ud by a thick, post-rift sedimentary sequence. The seismic data from the experiment indicate the presence of a thick, low-velocity zone, possibly representing overpressured sediments. They also indicate that the basement and\ud Moho in the center of the basin are both several kilometers shallower than previously inferred. These initial observations may have considerable impact on thermal models of the petroleum system in the basin. Understanding\ud the thermal history of potential source rocks is key to reducing hydrocarbon exploration risk. The experiment, which involved collaboration between university groups in the United Kingdom, Ireland, and Turkey, and BP and\ud Turkish Petroleum (TPAO), formed part of a larger project that also is using deep seismic reflection and other geophysical data held by the industry partners to determine the subsidence history and hence the strain evolution of\ud the basin

Desflurane in modern anaesthetic practice:walking on thin ice(caps)?

The third-generation volatile anaesthetic agents desflurane and sevoflurane were introduced into clinical practice in the 1990s in response to the perceived need for rapid return of consciousness after ambulatory surgery. Initially marketed by two competing pharmaceutical companies, their relative merits have been debated for three decades. Of the two, desflurane has a lower solubility in blood and therefore the fastest offset, providing a rapid emergence, which is more notable in obese patients and after prolonged anaesthesia. Furthermore, some authorities (including the US Food and Drug Administration [FDA]) have deemed desflurane to be more suitable than sevoflurane for low-flow anaesthesia, as it undergoes only negligible metabolism and minimal reaction with soda lime. However, desflurane has several well-known disadvantages, including a pungent odour (making it a respiratory irritant), lower potency, and environmental impacts related to its manufacture, administration, and discharge into the atmosphere, calling into question its continued use as a general anaesthetic agent

Eruptions of Magnetic Ropes in Two Homologous Solar Events on 2002 June 1 and 2: a Key to Understanding of an Enigmatic Flare

The goal of this paper is to understand the drivers, configurations, and scenarios of two similar eruptive events, which occurred in the same solar active region 9973 on 2002 June 1 and 2. The June 2 event was previously studied by Sui, Holman, and Dennis (2006, 2008), who concluded that it was challenging for popular flare models. Using multi-spectral data, we analyze a combination of the two events. Each of the events exhibited an evolving cusp-like feature. We have revealed that these apparent ``cusps'' were most likely mimicked by twisted magnetic flux ropes, but unlikely to be related to the inverted Y-like magnetic configuration in the standard flare model. The ropes originated inside a funnel-like magnetic domain whose base was bounded by an EUV ring structure, and the top was associated with a coronal null point. The ropes appear to be the major drivers for the events, but their rise was not triggered by reconnection in the coronal null point. We propose a scenario and a three-dimensional scheme for these events in which the filament eruptions and flares were caused by interaction of the ropes.Comment: 22 pages, 11 figure

Very long optical path-length from a compact multi-pass cell

The multiple-pass optical cell is an important tool for laser absorption spectroscopy and its many applications. For most practical applications, such as trace-gas detection, a compact and robust design is essential. Here we report an investigation into a multi-pass cell design based on a pair of cylindrical mirrors, with a particular focus on achieving very long optical paths. We demonstrate a path-length of 50.31 m in a cell with 40 mm diameter mirrors spaced 88.9 mm apart - a 3-fold increase over the previously reported longest path-length obtained with this type of cell configuration. We characterize the mechanical stability of the cell and describe the practical conditions necessary to achieve very long path-lengths