Diffusion and Home Range Parameters for Rodents: Peromyscus maniculatus in New Mexico

We analyze data from a long term field project in New Mexico, consisting of repeated sessions of mark-recaptures of Peromyscus maniculatus (Rodentia: Muridae), the host and reservoir of Sin Nombre Virus (Bunyaviridae: Hantavirus). The displacements of the recaptured animals provide a means to study their movement from a statistical point of view. We extract two parameters from the data with the help of a simple model: the diffusion constant of the rodents, and the size of their home range. The short time behavior shows the motion to be approximately diffusive and the diffusion constant to be 470+/-50m^2/day. The long time behavior provides an estimation of the diameter of the rodent home ranges, with an average value of 100+/-25m. As in previous investigations directed at Zygodontomys brevicauda observations in Panama, we use a box model for home range estimation. We also use a harmonic model in the present investigation to study the sensitivity of the conclusions to the model used and find that both models lead to similar estimates.Comment: The published paper in Ecol. Complexity has an old version of Figure 6. Here we have put the correct version of Figure

Demographic variation in nutrition knowledge in England

This paper describes a nutrition knowledge survey carried out on a cross-section of the adult population of England (n = 1040), looking at knowledge relating to current dietary recommendations, sources of nutrients, healthy food choices and diet-disease links. Serious gaps in knowledge about even the basic recommendations were discovered, and there was much confusion over the relationship between diet and disease. Significant differences in knowledge between socio-demographic groups were found, with men having poorer knowledge than women, and knowledge declining with lower educational level and socio-economic status. Possible reasons for these differences and implications for public education campaigns and socio-economic inequalities in health are discussed

Following the rivers: historical reconstruction of California voles Microtus californicus (Rodentia: Cricetidae) in the deserts of eastern California

The California vole, Microtus californicus, restricted to habitat patches where water is available nearly year-round, is a remnant of the mesic history of the southern Great Basin and Mojave deserts of eastern California. The history of voles in this region is a model for species-edge population dynamics through periods of climatic change. We sampled voles from the eastern deserts of California and examined variation in the mitochondrial cytb gene, three nuclear intron regions, and across 12 nuclear microsatellite markers. Samples are allocated to two mitochondrial clades: one associated with southern California and the other with central and northern California. The limited mtDNA structure largely recovers the geographical distribution, replicated by both nuclear introns and microsatellites. The most remote population, Microtus californicus scirpensis at Tecopa near Death Valley, was the most distinct. This population shares microsatellite alleles with both mtDNA clades, and both its northern clade nuclear introns and southern clade mtDNA sequences support a hybrid origin for this endangered population. The overall patterns support two major invasions into the desert through an ancient system of riparian corridors along streams and lake margins during the latter part of the Pleistocene followed by local in situ divergence subsequent to late Pleistocene and Holocene drying events. Changes in current water resource use could easily remove California voles from parts of the desert landscape

Error analysis for station position from tracking of the Lageos satellite

The earth physics satellite systems error analysis program was applied to the problem of predicting the relative accuracy of station position determinations under varying orbital and observing geometries. The reference case consists of nine ground stations extending over 1500 km which lasers ranged to a LAGEOS satellite, with simultaneous Doppler tracking from a geosynchronous satellite for 16 days. Eleven variations from the reference case were tested. The results showed little sensitivity to whether the LAGEOS altitude is 3700 or 5690 km. More significant were the high inclination, and that LAGEOS was tracked by a geosynchronous satellite

Transferable skills for global employability in PhD curriculum transformation

Over the past twenty years, higher education has experienced greatly increased doctoral enrolments and corresponding changes in career destinations. Until recently, most graduates could expect to secure academic positions, but this career path is no longer assured or necessarily desired. For example, in the UK, only 14% of PhD students now secure an academic post, and only 19% of UK PhD holders were in higher education research roles three years after graduating. The increasing proportion and diversity of people holding a doctorate is leading to a transformation in how governments, employers, and degree holders themselves consider career possibilities for doctoral graduates. This change in the doctoral demographic and concomitant employment possibilities has precipitated a focus on the development of generic (transferable) skills in addition to the PhD research content itself. Consequently, a range of researcher development programmes has been established, notably national initiatives such as Vitae in the UK and institution-specific initiatives. This expansion of focus has implications for curriculum, with employability as a key driver for what and how we teach doctoral students. However, in facilitating and achieving such curriculum transformation, students’ views of how their experiences and learning have supported, enhanced, or hindered their career and life opportunities have seldom been sought. This issue becomes even more pertinent when discussion is extended to the global sphere. The OECD average for international students in doctoral programmes is 24%, which includes traditionaltype international students who travel to host countries to study. The number increases further when doctoral students in programmes designed in line with “international” standards, but taught by international faculty in a home country context, are added. What do these students consider appropriate preparation for their future employment in terms of transferable skills, and what challenges do they perceive when seeking jobs? Using perspectives gained from an empirical study on transferable skills conducted with doctoral students in New Zealand and the experiences of curriculum transformation in a PhD programme in Kazakhstan designed in collaboration with strategic partners in the UK and USA, the presenters will engage delegates in discussion of doctoral curriculum transformation and transferable skills in a global context. Doctoral candidates are especially welcome at the round table to share their own experiences

Badnavirus sequences identified from Passiflora spp. in Guadeloupe and Australia [Abstract]

Badnaviruses (family Caulimoviridae, genus Badnavirus) have non-enveloped bacilliform particles containing a single copy of a circular dsDNA genome of c. 7.4R7.6 kbp arranged in at least three conserved open reading frames. Badnaviruses are transmitted in a semi-persistent mode by mealybugs and, for some species, also by aphids, scale insects or lacebugs. Several badnaviruses infect economically important tropical crops such as banana, cocoa, pineapple, sugarcane, taro and yam, and have a serious impact on yields. Over the past 10 years, endogenous viral sequences have been discovered and characterized in the genome of numerous crops, including badnavirus sequences in the genome of banana, yam and pineapple. It is expected that in silico analysis of plant genomic sequence data will reveal more endogenous viral sequences. Passiflora spp. from Guadeloupe and Australia were screened for badnavirus sequences by PCR across the conserved reverse transcriptase/RNaseH region of the ORF 3 polyprotein. PCR was performed on purified total DNA, using two sets of degenerate primers. Badnavirus sequences were amplified from Passiflora edulis f. flavicarpa, a yellow mutant introduced to Australia and Guadeloupe in the beginning of the XXth century. Badnavirus sequences were also amplified from species P. edulis, P. foetida, P. laurifolia, P. maliformis, P. quadrangularis and P. serrato-digitata, which were introduced in Guadeloupe from South and Central America at the turn of the XXth century. On the contrary, no badnavirus sequences could be amplified from Australian native P. aurantia and P. herbertiana. Phylogenetic analyses show that there is no host speciation of badnavirus sequences in the Passiflora spp. used in this work. They also show that P. edulis samples from Guadeloupe and Australia share highly similar sequences. The nature of these sequences (episomal vs integrated) is currently being explored. Although no badnavirus has been reported yet in Passiflora spp., bacilliform particles could be observed in an Australian P. edulis f. flavicarpa plant showing severe fruit puckering and leaf shoestring symptoms. Nevertheless, all other plants used in this study were asymptomatic. (Texte intégral