Evidence for the Galactic X-ray Bulge II

A mosaic of 5 \ros~PSPC pointed observations in the Galactic plane ($l\sim25^{\circ}$) reveals X-ray shadows in the $0.5-2.0$ keV band cast by distant molecular clouds. The observed on-cloud and off-cloud X-ray fluxes indicate that $\sim15$% and $\sim37$% of the diffuse X-ray background in this direction in the \tq~keV and 1.5 keV bands, respectively, originates behind the molecular gas which is located at $\sim$3 kpc from the Sun. The implication of the derived background X-ray flux beyond the absorbing molecular cloud is consistent with, and lends further support to recent observations of a Galactic X-ray bulge.Comment: 19 pages, 5 figures, 2 table

Importance of the loading factor in transport CO2 emissions

This paper is focusing on the influence of the loading factor on CO2 emissions, from freight and passengers. A common approach in economics to relate greenhouse gas (GHG) emissions to economic activity is the ASIF model (Unander & Schipper 2000). However, this model has been elaborated for all economic sectors, and it doesn’t take into account the vehicle load factor for the calculation of transport emissions. The objective of this paper is to include the loading factor into the ASIF approach. First, we will include this loading factor into the ASIF equation, aggregating step by step from trip level to macro level; loading will appear as a result of empty running, vehicle capacity and occupancy rate (section 2). Then section 3 will analyse the relationship between loading factor and energy consumption, per type of vehicle. Section 4 will focus on issues concerning freight, as well as section 5 for passengers. The examples will be mainly taken from road transport, which causes most of transport CO2 emissions. Then our conclusion will draw attention on data needs and policy implications

Ephyrae and metaephyrae of Pelagia noctiluca: stage determination, morphometry and shrinkage

Understanding processes occurring in the different life stages of jellyfish is key to advance knowledge on their trophic interactions and population dynamics. We describe four developmental stages of Pelagia noctiluca ephyrae and metaephyrae based on the progress of feeding structures and morphometric measurements on the central disc diameter and total body diameter. Size differs significantly among stages, but it can overlap substantially, suggesting that it is not always coupled with development progress due to different somatic growth. Morphological distinction of stages is biologically important because it implies different levels of food specialization and capture efficiency. We further report a 25% (±13 SD) shrinkage of ephyrae and metaephyrae after storage in 4% formaldehyde solution. This metric can be used in ecological studies focusing on size-related traits of field observed individuals.Postprint1,74

Bluefin tuna larval indices in the western Mediterranean, ecological and analytycal sources of uncertainity

The main objective of this study is to provide the knowledge to design adequate sensitivity analyses on the assessment models used for the Eastern stock of Bluefin tuna. We analyze how different configuration for the same environmental variable (temperature in the mixed layer depth) and different modeling approaches (nonlinear Delta-log,delta-gamma, tweedy and bayesian) affects to the variability of the larval indices of the Eastern bluefin tuna from data collected in the Balearic Sea (Western Mediterranean). We also investigate the effects on the index caused from having differences in the total sampled area among years. We used these results to interpolate larval index values in years with not standard larval surveys but with some ichthyoplankton surveys available, and to propose a “revised version” of the index providing parameters of uncertainty

ASCA Observation of an "X-ray Shadow" in the Galactic Plane

The diffuse X-ray background (DXB) emission near the Galactic plane ($l,b \sim 25.6^{\circ},0.78^{\circ}$) has been observed with $ASCA$. The observed region is toward a Galactic molecular cloud which was recently reported to cast a deep X-ray shadow in the 0.5 $-$ 2.0 keV band DXB. The selection of this particular region is intended to provide a constraint on the spatial distribution of the DXB emission along the line of sight: i.e., the molecular cloud is optically thick at $<$2 keV and so the bulk of the observed soft X-rays {\it must} originate in the foreground of the cloud, which is at $\sim$3 kpc from the Sun. In the 0.8 $-$ 9.0 keV band, the observed spectrum is primarily from multiple components of thermal plasmas. We here report a detection of soft X-ray (0.5 $-$ 2 keV) emission from an $\sim10^{7}$ K thermal plasma. Comparisons with the {\it ROSAT} data suggest that this soft X-ray emission is absorbed by $N_H$ = 1 $-$ 3 $\times$ 10$^{21}$ cm$^{-2}$, which implies a path-length through the soft X-ray emitting regions of \la1 kpc from the Sun.Comment: 24 pages including 8 figures, accepted for Ap

Small fish eat smaller fish: A model of interaction strength in early life stages of two tuna species

Fish larvae are rarely a major driver of fish mortality, but tunas can produce large batches of larvae that rapidly develop the capacity to kill other fish. We combine a model for the killing potential from Atlantic bluefin tuna (BFT) larvae on larval albacore (ALB) with field observations at a major spawning ground. Both species spawn from June to August, but BFT has a narrow spawning peak at the beginning of the season that results in priority effects. Our model shows that, following a recent stock recovery, BFT larvae have increased their killing pressure, leaving areas of up to 1000 km2 with < 1% chance of ALB daily survival. Such increase in killing pressure suggests larval ALB has reduced chances to survive; yet in large areas with few BFT, other drivers of early survival prevail over BFT predation. This shows that strong predatory interactions can occur during larval stages in some fishes.En prensa3,38

Client self-assessment in community aged care: A comparative study involving older Australians and their case managers

Self-assessment of support needs is a relatively new and under-researched phenomenon in domiciliary aged care. This article outlines the results of a comparative study focusing on whether a self-assessment approach assists clients to identify support needs and the degree to which self-assessed needs differ from an assessment conducted by community care professionals. A total of 48 older people and their case managers completed a needs assessment tool. Twenty-two semi-structured interviews were used to ascertain older people&rsquo;s views and preferences regarding the self-assessment process. The study suggests that while a co-assessment approach as outlined in this article has the potential to assist older people to gain a better understanding of their care needs as well as the assessment process and its ramifications, client self-assessment should be seen as part of a co-assessment process involving care professionals. Such a co-assessment process allows older people to gain a better understanding of their support needs and the wider community aged care context. The article suggests that a co-assessment process involving both clients and care professionals contains features that have the capacity to enhance domiciliary aged care

Spawning site distribution of a bluefin tuna reduces jellyfish predation on early life stages

Bluefin tunas across the world migrate long distances to spawn in particularly warm and oligotrophic areas constrained by oceanographic fronts. The low abundance of predators in these areas increases survival chances of their early life stages, but its importance for choice of spawning habitat is unknown. Here, we use estimated clearance rates and data on spatial distributions of Atlantic bluefin tuna larvae Thunnus thynnus and metaephyrae of the jellyfish Pelagia noctiluca to quantify predation at a major spawning ground in the Mediterranean Sea. We found that high densities of P. noctiluca can rapidly deplete tuna eggs and preflexion larvae, but their patchy distribution and low spatial and temporal overlap results in overall low predation. The specific distribution of the spawning sites suggests that bluefin tunas may use local oceanography as cues to spawn outside areas with high predator densities.Postprint3,38

On the Contribution of Unresolved Galactic Stars to the Diffuse Soft X-ray Background

Using stellar luminosity functions derived from ROSAT data, the contributions of Galactic stars to the diffuse X-ray background are calculated for ROSAT PSPC energy bands. The model follows that of Guillout et al. (1996), but uses ROSAT rather than {\it Einstein} data to determine the intrinsic luminosity distributions. The model adequately predicts the numbers of stellar sources observed in deep ROSAT surveys. The contribution of unresolved stellar sources to the ROSAT All-Sky Survey at the Galactic poles is 6.85, 4.76, and 4.91 $\times$ counts s$^{-1}$ arcmin$^{-2}$ in bands R12 (1/4 keV), R45(3/4 keV), and R67(1.5 keV), respectively, which is equivalent to 4.66, 31.3 and 26.9 $\times10^{-14}$ ergs cm$^{-2}$ s$^{-1}$ deg$^{-2}$.Comment: 14 pages, 8 figures, accepted by Ap

Evidence for an X-ray Emitting Galactic Bulge: Shadows Cast by Distant Molecular Gas

A mosaic of 7 ROSAT PSPC pointed observations in the direction of (l,b ~ 10,0 deg) reveals deep X-ray shadows in the 0.5-2.0 keV band cast by dense molecular gas. The comparison between the observed on-cloud and off-cloud X-ray fluxes indicates that ~43% of the diffuse X-ray background in this direction in both the 3/4 keV and 1.5 keV bands originates behind the molecular gas, which is located at 2-4 kpc from the Sun. Given the short mean free path of X-rays in the 3/4 keV band in the Galactic plane (~1 kpc assuming an average space density of 1 cm^-3), this large percentage of the observed flux which originates beyond the molecular gas most likely indicates a strong enhancement in the distribution of X-ray emitting gas in the Galactic center region, possibly associated with a Galactic X-ray bulge.Comment: 16 pages LaTex, 2 figures. Accepted for the publication in Astrophysical Journal, Letter