Galactic cosmic ray hazard in the unusual extended solar minimum between solar cycle 23 and 24

Galactic cosmic rays (GCRs) are extremely difficult to shield against and pose one of the most severe long-term hazards for human exploration of space. The recent solar minimum between solar cycles 23 and 24 shows a prolonged period of reduced solar activity and low interplanetary magnetic field strengths. As a result, the modulation of GCRs is very weak, and the fluxes of GCRs are near their highest levels in the last 25 years in the fall of 2009. Here we explore the dose rates of GCRs in the current prolonged solar minimum and make predictions for the Lunar Reconnaissance Orbiter (LRO) Cosmic Ray Telescope for the Effects of Radiation (CRaTER), which is now measuring GCRs in the lunar environment. Our results confirm the weak modulation of GCRs leading to the largest dose rates seen in the last 25 years over a prolonged period of little solar activity.

Cognitive tests used in chronic adult human randomised controlled trial micronutrient and phytochemical intervention studies

In recent years there has been a rapid growth of interest in exploring the relationship between nutritional therapies and the maintenance of cognitive function in adulthood. Emerging evidence reveals an increasingly complex picture with respect to the benefits of various food constituents on learning, memory and psychomotor function in adults. However, to date, there has been little consensus in human studies on the range of cognitive domains to be tested or the particular tests to be employed. To illustrate the potential difficulties that this poses, we conducted a systematic review of existing human adult randomised controlled trial (RCT) studies that have investigated the effects of 24 d to 36 months of supplementation with flavonoids and micronutrients on cognitive performance. There were thirty-nine studies employing a total of 121 different cognitive tasks that met the criteria for inclusion. Results showed that less than half of these studies reported positive effects of treatment, with some important cognitive domains either under-represented or not explored at all. Although there was some evidence of sensitivity to nutritional supplementation in a number of domains (for example, executive function, spatial working memory), interpretation is currently difficult given the prevailing 'scattergun approach' for selecting cognitive tests. Specifically, the practice means that it is often difficult to distinguish between a boundary condition for a particular nutrient and a lack of task sensitivity. We argue that for significant future progress to be made, researchers need to pay much closer attention to existing human RCT and animal data, as well as to more basic issues surrounding task sensitivity, statistical power and type I error.

Current level of consensus on probiotic science: report of an expert meeting, London, 23 November 2009

The present paper summarizes  the consensus views of a group of 9 European clinicians and scientists on the current state of scientific knowledge on probiotics, covering those areas where there is substantial evidence for beneficial effects and those  where the evidence base is poor or inconsistent. There was general agreement that probiotic effects were species and often strain specific. The experts agreed  that some probiotics were effective in reducing the incidence and duration of rotavirus diarrhoea in infants, antibiotic-associated diarrhoea in adults and, for certain probiotics, Clostridium difficile infections. Some probiotics are associated with symptomatic improvements in irritable bowel syndrome and alleviation of digestive discomfort. Probiotics can reduce the frequency and severity of necrotizing enterocolitis in premature infants and have been shown to regulate intestinal immunity.  Several other clinical effects of probiotics, including their role in inflammatory bowel disease, atopic dermatitis, respiratory or genito-urinary infections or H.pylori adjuvant treatment were thought promising but inconsistent.

SPI-23 of S.Derby: role in adherence and invasion of porcine tissues

Salmonella enterica serovars Derby and Mbandaka are isolated from different groups of livestock species in the UK. S. Derby is predominantly isolated from pigs and turkeys and S. Mbandaka is predominantly isolated from cattle and chickens. Alignment of the genome sequences of two isolates of each serovar led to the discovery of a new putative Salmonella pathogenicity island, SPI-23, in the chromosome sequence of S. Derby isolates. SPI-23 is 37 kb in length and contains 42 ORFs, ten of which are putative type III effector proteins. In this study we use porcine jejunum derived cell line IPEC-J2 and in vitro organ culture of porcine jejunum and colon, to characterise the association and invasion rates of S. Derby and S. Mbandaka, and tissue tropism of S. Derby respectively. We show that S. Derby invades and associates to an IPEC-J2 monolayer in significantly greater numbers than S. Mbandaka, and that S. Derby preferentially attaches to porcine jejunum over colon explants. We also show that nine genes across SPI-23 are up-regulated to a greater degree in the jejunum compared to the colon explants. Furthermore, we constructed a mutant of the highly up-regulated, pilV-like gene, potR, and find that it produces an excess of surface pili compared to the parent strain which form a strong agglutinating phenotype interfering with association and invasion of IPEC-J2 monolayers. We suggest that potR may play a role in tissue tropism.

Vertical ion flow in the polar ionosphere

Outflowing ions from the polar ionosphere fall into two categories: the classical polar wind and the suprathermal ion flows. The flows in both these categories vary a great deal with altitude. The classical polar wind is supersonic at high altitude: at ∼3 RE geocentric, the observed polar wind is H+ dominated and has a Mach number of 2.5–5.1. At 400–600 km, thermal and suprathermal upward O+ ion fluxes frequently occur at the poleward edge of the nightside auroral oval during magnetically active times. Above 500 km, ions are accelerated transverse to the local geomagnetic field. At 1400 km, transversely accelerated ions are frequently observed in winter nights but rarely appear in the summer. In the dayside cleft above ∼2000 km, ions of all species are transversely heated and upwell with significant number and heat fluxes, forming a cleft ion fountain as they convect across the polar cap. Upwelling ions are observed most (least) frequently in the summer (winter). At yet higher altitudes, energetic (>10 eV to several kiloelectron volts) upflowing H+ and O+ ions are frequently observed, their active time occurrence frequency being as high as 0.7 at auroral latitudes and 0.3 in the polar cap. Their composition, intensity, and angular characteristics vary quantitatively with solar activity, being O+ dominant and more intense near solar maximum. Their resulting ion outflow is dominated by ions below 1 keV and reaches 3.5×10^26 O+ and 7×10^25 H+ ions s^{−1} at magnetically active times (Kp≥5) near solar maximum. In comparison, the estimated polar wind ion outflow at times of moderate solar activity is 7×10^25H+ and 4×10^24 He+ ions s^{−1}. The estimated <10-eV cleft ion fountain flow is 3.8×10^25 O+ and 8.6×10^23 H+ ions s^{−1} near solar maximum.

LOFZY 2005 - Field experiment on Cyclones over the Norwegian Sea: meteorological measurements of the research aircraft Falcon, 23 autonomous water buoys and radiosoundings at the research vessel Celtic Explorer

The field campaign LOFZY 2005 (LOFoten ZYklonen, engl.: Cyclones) was carried out in the frame of Collaborative Research Centre 512, which deals with low-pressure systems (cyclones) and the climate system of the North Atlantic. Cyclones are of special interest due to their influence on the interaction between atmosphere and ocean. Cyclone activity in the northern part of the Atlantic Ocean is notably high and is of particular importance for the entire Atlantic Ocean. An area of maximum precipitation exists in front of the Norwegian Lofoten islands. One aim of the LOFZY field campaign was to clarify the role cyclones play in the interaction of ocean and atmosphere. In order to obtain a comprehensive dataset of cyclone activity and ocean-atmosphere interaction a field experiment was carried out in the Lofoten region during March and April 2005. Employed platforms were the Irish research vessel RV Celtic Explorer which conducted a meteorological (radiosondes, standard parameters, observations) and an oceanographic (CTD) program. The German research aircraft Falcon accomplished eight flight missions (between 4-21 March) to observe synoptic conditions with high spatial and temporal resolution. In addition 23 autonomous marine buoys were deployed in advance of the campaign in the observed area to measure drift, air-temperature and -pressure and water-temperature. In addition to the published datasets several other measurements were performed during the experiment. Corresonding datasets will be published in the near future and are available on request. Details about all used platforms and sensors and all performed measurements are listed in the fieldreport. The following datasets are available on request: ground data at RV Celtic Explorer