The photodisintegration of cosmic ray nuclei by solar photons: the Gerasimova-Zatsepin effect revisted

The interesting possibility of measuring the masses of high energy cosmic ray particles by observing pairs of extensive air showers arriving at the earth nearly simultaneously was proposed some years ago by Gerasimova and Zatsepin (1960). Such showers would be created by the nuclear fragments originating as a result of the photodisintegration of massive nuclei interacting with the solar radiation field. In this paper we re-visit this possibility in the context of existing and proposed detectors of high and ultra-high energy cosmic rays considering a simple, yet realistic, model of the interplanetary magnetic field. The possibilty of observing the mass fragmentation of cosmic rays directly, however, remains challenging.Comment: 14 pages, 7 figures (3 ps + 4 jpg), Astroparticle Physics (in press) - typos corrected and other minor modification

Cosmic Rays above 101410^{14} eV

We briefly review the status of cosmic ray studies between $10^{14}$ eV and the highest observed energies, namely a few times $10^{20}$ eV. Because of the rather low incident fluxes in this energy range, the studies mostly rely on ground based, large aperture detectors reconstructing the cosmic ray's properties through the detection of the air-showers they generate by interacting with the atmosphere. We stress the fact that many issues such as the chemical composition of the cosmic rays, their acceleration mechanisms, the structures displayed in their energy spectrum are mostly open questions which may be answered by the next generation of experiments.Comment: 11 pages, 5 figures, Latex2e, one reference modifie

Extreme asteroids in the Pan-STARRS 1 Survey

Using the first 18 months of the Pan-STARRS 1 survey we have identified 33 candidate high-amplitude objects for follow-up observations and carried out observations of 22 asteroids. 4 of the observed objects were found to have observed amplitude $A_{obs}\geq 1.0$ mag. We find that these high amplitude objects are most simply explained by single rubble pile objects with some density-dependent internal strength, allowing them to resist mass shedding even at their highly elongated shapes. 3 further objects although below the cut-off for 'high-amplitude' had a combination of elongation and rotation period which also may require internal cohesive strength, depending on the density of the body. We find that none of the 'high-amplitude asteroids' identified here require any unusual cohesive strengths to resist rotational fission. 3 asteroids were sufficiently observed to allow for shape and spin pole models to be determined through light curve inversion. 45864 was determined to have retrograde rotation with spin pole axes $\lambda=218\pm 10^{\circ}, \beta=-82\pm 5^{\circ}$ and asteroid 206167 was found to have best fit spin pole axes $\lambda= 57 \pm 5^{\circ}$, $\beta=-67 \pm 5^{\circ}$. An additional object not initially measured with $A_{obs}>1.0$ mag, 49257, was determined to have a shape model which does suggest a high-amplitude object. Its spin pole axes were best fit for values $\lambda=112\pm 6^{\circ}, \beta=6\pm 5^{\circ}$. In the course of this project to date no large super-fast rotators ($P_{rot} < 2.2$ h) have been identified.Comment: 31 pages; accepted by A

Agonistic Behaviour and Biogenic Amines in Shore Crabs Carcinus Maenas

To investigate the role of certain neurohormones in agonistic behaviour, fights were staged between pairs of size-matched male shore crabs Carcinus maenas, and blood samples were taken immediately after the contests had been resolved. Samples were also taken from these crabs at rest (before and after fighting) and after walking on a treadmill. A control group of crabs also had samples taken on each experimental day. Concentrations of tyramine, dopamine, octopamine, serotonin (5-HT) and norepinephrine were determined in each blood sample using a gas chromatography/mass spectrometry (GC-MS) system. Norepinephrine was not detectable in any of the samples, but the standards were recovered. Tyramine values were not significantly different between the control group and the fought group, so tyramine does not appear to be important in agonistic behaviour. A comparison between the control and fought groups shows that fighting had an effect on the concentrations of octopamine, dopamine and 5-HT, but exercise only had an effect on octopamine levels, which showed a reduction from resting values in both winners and losers. Resting and post-fight concentrations of octopamine, dopamine and 5-HT were higher in winners than in losers. 5-HT concentration increased in the blood of fought crabs from resting values, whereas dopamine concentration decreased. In winners, octopamine concentrations decreased from resting values, but in losers octopamine levels increased from resting concentrations. The escalatory behaviour or intensity of fighting performed by winners and losers was related to dopamine levels but not to those of octopamine or 5-HT. Therefore, there appears to be a link between relative concentrations of these three amines (dopamine, octopamine and 5-HT) and fighting ability; the effects are not simply a result of activity. The better competitors have higher concentrations of these three amines at rest and after fighting

Public Purpose Recreation Marketing: A Focus on the Relationships Between the Public and Public Lands

Marketing has long had a place in the planning and management of public sector recreation. In particular, the use of market segmentation has allowed leisure providers to better understand their clients’ needs and to tailor their services to the diversity of those needs. However, the use of marketing approaches is not without controversy and is sometimes perceived to be at odds with the public service or stewardship mandates often associated with recreation management. We suggest that wholesale adoption of basic marketing principles (such as the notion of giving people exactly what they want at a great price) may be inappropriate. An alternative form, relational marketing, may be better suited to public purpose organizations. Relational marketing focuses on the development or fostering of a relationship between the public and the public agency. Thus, relational marketing focuses on building confidence in the agency’s ability to guard the short- and long-term interests of the public. For example, for land management agencies, these objectives are embedded in legislative and policy mandates to provide outstanding opportunities for recreation, while at the same time protecting and enhancing the environment. Relational marketing seems better suited to these objectives compared with transactional marketing, which is more dominant in private sector businesses. Whereas transactional marketing focuses on fostering current and continuing purchases of goods and services, relational marketing extends beyond the direct economic exchange. In the public recreation settings, the public is considered more than a current or potential customer, they are also considered an owner or shareholder of the agency. Thus, repeat purchases or customer satisfaction are not sufficient measures of success for organizations with a public service mandate. Instead, relational marketing considers the perceptions that the many different groups of the public (e.g. participants and non-participants, supporters and non-supporters) have of the agency and its actions. The research reported here conceptualizes the relationship between the public and the agency into three dimensions: social trust (the degree to which individuals perceive the agency to share their views, goals, and values); commitment (the investment, attachment, and longevity of the relationship to the agency); and social responsibility (which includes attitudes towards the goals or public purposes of the agency). A market segmentation based on these dimensions yielded distinct subpopulations of the general public. The challenge for public agencies, such as the Forest Service, is to be responsive to the different relationships the public has with the agency. Collaborative planning efforts must acknowledge and incorporate knowledge of these differences in social trust, commitment, and social responsibility. Any public action or policy change should consider how it potentially affects the varying public’s relationship with the agency and the services it provides. Managers must demonstrate stewardship, care, responsiveness, and continuing service to today’s public and future generations. Any interaction with the public (e.g., marketing) should focus on the intended public purpose which guides the agency

Identification and annotation of conserved promoters and macrophage-expressed genes in the pig genome.

BACKGROUND: The FANTOM5 consortium used Cap Analysis of Gene Expression (CAGE) tag sequencing to produce a comprehensive atlas of promoters and enhancers within the human and mouse genomes. We reasoned that the mapping of these regulatory elements to the pig genome could provide useful annotation and evidence to support assignment of orthology. RESULTS: For human transcription start sites (TSS) associated with annotated human-mouse orthologs, 17% mapped to the pig genome but not to the mouse, 10% mapped only to the mouse, and 55% mapped to both pig and mouse. Around 17% did not map to either species. The mapping percentages were lower where there was not clear orthology relationship, but in every case, mapping to pig was greater than to mouse, and the degree of homology was also greater. Combined mapping of mouse and human CAGE-defined promoters identified at least one putative conserved TSS for >16,000 protein-coding genes. About 54% of the predicted locations of regulatory elements in the pig genome were supported by CAGE and/or RNA-Seq analysis from pig macrophages. CONCLUSIONS: Comparative mapping of promoters and enhancers from humans and mice can provide useful preliminary annotation of other animal genomes. The data also confirm extensive gain and loss of regulatory elements between species, and the likelihood that pigs provide a better model than mice for human gene regulation and function

A novel cellular pathway of antigen presentation and CD4 T cell activation in vivo

Dendritic cell activation of CD4 T cells in the lymph node draining a site of infection or vaccination is widely considered the central event in initiating adaptive immunity. The accepted dogma is that this occurs by stimulating local activation and antigen acquisition by dendritic cells, with subsequent lymph node migration, however the generalizability of this mechanism is unclear. Here we show that in some circumstances antigen can bypass the injection site inflammatory response, draining freely and rapidly to the lymph nodes where it interacts with subcapsular sinus (SCS) macrophages resulting in their death. Debris from these dying SCS macrophages is internalized by monocytes recruited from the circulation. This coordinated response leads to antigen presentation by monocytes and interactions with naïve CD4 T cells that can drive the initiation of T cell and B cell responses. These studies demonstrate an entirely novel pathway leading to initiation of adaptive immune responses in vivo