Oithona similis in a high latitude ecosystem: abundance, distribution and temperature limitation of fecundity rates in a sac spawning copepod

In this study we report the abundance, fecundity and an index of mortality of Oithona similis across a large latitudinal and temperature range within the Southern Ocean. The abundance of O. similis was strongly related to temperature and to depthintegrated (0-100m) chorophyll a (Chl a), abundance increasing with increasing temperature (and therefore increasing latitude) and Chl a. In situ total egg production rates and fecundity per female were significantly and positively related to temperature and Chl a. Egg hatch times lengthen as temperature decreases and in sac spawning species the next batch of eggs cannot be produced until the previous clutch hatch. Consequently, O. similis fecundity rates must rapidly decline at low temperatures, especially below 5oC. In situ fecundity rates were compared with a model of maximum fecundity, and were generally much lower, thus suggesting strong food limitation across the region studied. However the relationships of in situ and maximum rates to temperature were similar, confirming the importance of temperature. Further, as time taken to develop from egg to adult also rapidly extends with declining temperature, it is increasingly unlikely that O. similis will be able to 2 maintain its population against typical field mortality. Our findings have broad implications for the lower temperature range and hence geographic limits of O. similis, but also for the distribution of other sac spawning copepods and planktonic species generall

Rural transport and older people in Lincolnshire : research report in association with the Policy Studies Research Centre and Lincoln Business School

Executive Summary • The population of the UK is ageing and it is predicted that by 2035 people aged 65 and over will comprise 23% of the total UK population. • These changing demographics are particularly noticeable in rural areas of the UK, where the median age of a rural resident is 42, compared to 36 for an urban resident. The out-migration of younger age groups and the selective re-population of many of England’s rural areas with older age groups, means that the rural population is simultaneously growing and ageing. • Research indicates that among post-retirement older people there is a clear connection between transport and social exclusion, which is especially marked in rural areas. Accessible transport is therefore a key factor in preventing social isolation, facilitating independence and maintaining a high quality of life. • This report was commissioned to examine these issues and investigate the current and future transportation needs of older people in Lincolnshire after transport was listed as one of three top priorities for older people in a consultation with this age group in the county. • The report will form part of a wider proposal to develop a community transport strategy for Lincolnshire, supported by a marketing and communication plan for transport services for older people. • If well planned, community transport can form a vital component of an integrated transport system as it provides an important passenger transport resource, which complements other transport services such as local bus and rail networks and Demand Responsive Transport (DRT) schemes such as CallConnect. • In so doing, community transport helps to provide and enhance passenger transport accessibility and reduce social isolation in rural areas and for particular categories of people (such as older people), who can find it difficult to access public transport. The main conclusions which emerged from the research are as follows: • There was a severe lack of knowledge amongst participants about what community transport schemes existed, how they operated and what services they offered. • There appeared to be a negative relationship between the number of community transport providers and high levels of socio-economic deprivation. For example, in Gainsborough there were no voluntary/community car schemes, whilst in Louth, there was a large scheme, well operated and well used. However, despite these findings, there were still people living in Louth attending the focus group who had little or no idea about what a voluntary/community car scheme was or what other services like CallConnect could do for them. • The dominant role of the car in older people’s lives was noticeable: both men and women were very reluctant to give up driving and continued to drive into their 80s. • While some older people felt that their free bus passes were a ‘lifeline’, others felt they were less useful as there were not enough buses to use them on, could not use them due to mobility issues and the distance from their homes to a bus stop, or were not aware that they could be used on DRT services e.g. CallConnect. • A severe lack of coordination between transport services was reported by older people. These included connection times between different bus operators and also to railway stations. Furthermore there was also a variety of health care providers who older people felt gave little or no consideration as to how they were to get to appointments and how to deal with potential life changing events, e.g. the cessation of driving. • While many older people appeared to own mobile phones, very few used these to send text messages and no participants used their phone to access the internet. • Very few of the people interviewed used a computer, instead relying on their sons and daughters to find out information when they had no other option but to use a computer and access the internet. However, some older people did express a desire to learn more about computer technology and how to access the internet. • There are a lack of public and community transport services that operate during the evenings and at weekends in rural communities. This creates a feeling of isolation amongst the older people interviewed and difficulties in accessing essential amenities and services. Based on the research in this report, a series of short and longer term recommendations are suggested to increase the use of public and community transport services by older people in rural communities: Short term 1. The implementation of a promotional and marketing campaign that would raise awareness of different rural transport services available to older people 2. Further development of the Lincolnshire Community Transport Forum 3. The promotion of voluntary/community transport as a way to access healthcare Longer term 4. Greater opportunities for older people to access and learn about ICT for transport 5. The expansion of the concessionary bus pass scheme to be used on other transport service

The summertime plankton community at South Georgia (Southern Ocean): comparing the historical (1926/27) and modern (post 1995) records.

The earliest comprehensive plankton sampling programme in the Southern Ocean was 32 undertaken during the early part of last century by Discovery Investigations to gain a 33 greater scientific understanding of whale stocks and their summer feeding grounds. An 34 initial survey was carried out around South Georgia during December 1926 and January 35 1927 to describe the distribution of plankton during the summer, and to serve as a 36 baseline against which to compare future surveys. We have reanalysed phytoplankton and 37 zooplankton data from this survey and elucidated patterns of community distribution and 38 compared them with our recent understanding of the ecosystem based on contemporary 39 data. Analysis of Discovery data identified five groups of stations with characteristic 40 phytoplankton communities which were almost entirely consistent with the original 41 analysis conducted by Hardy and Gunther (1935). Major groupings were located at the 42 western end of the island and over the northern shelf where Corethron spp. were 43 dominant, and to the south and east where a more diverse flora included high abundances 44 of Nitzschia seriata. Major zooplankton-station groupings were located over the inner 45 shelf which was characterised by a high abundance of Drepanopus forcipatus and in 46 oceanic water >500 m deep that were dominated by Foraminifera, Oithona spp., 47 Ctenocalanus vanus, and Calanoides acutus. Stations along the middle and outer shelf 48 regions to the north and west, were characterised by low overall abundance. There was 49 some evidence that groupings of stations to the north of the island originated in different 50 water masses on either side of the Southern Antarctic Circumpolar Current Front, the 51 major frontal system in the deep ocean close to South Georgia. However, transect lines 52 during 1926/27 did not extend far enough offshore to sample this frontal region 53 3 adequately. Interannual variability of zooplankton abundance was assessed from stations 54 which were sampled repeatedly during 7 recent British Antarctic Survey cruises (1995-55 2005) to the region and following taxonomic harmonization and numerical 56 standardization (ind. m-3), a subset of 45 taxonomic categories of zooplankton (species 57 and higher taxa) from 1926/27, were compared with similar data obtained during the 58 BAS cruises using a linear model. Initially comparisons were restricted to BAS stations 59 that lay within 40 km of Discovery stations although a comparison was also made using 60 all available data. Despite low abundance values in 1926/27, in neither comparison did 61 Discovery data differ significantly from BAS data. Calculation of the percentage 62 similarity index across cruises did not reveal any systematic differences in species 63 composition between 1926/27 and the present. In the light of ocean warming trends, the 64 existence of more subtle changes in species composition is not ruled out, but an absence 65 of finely resolved time-series data make this impossible to determine

Equality of P-partition generating functions

To every labeled poset (P,\omega), one can associate a quasisymmetric generating function for its (P,\omega)-partitions. We ask: when do two labeled posets have the same generating function? Since the special case corresponding to skew Schur function equality is still open, a complete classification of equality among (P,\omega) generating functions is likely too much to expect. Instead, we determine necessary conditions and separate sufficient conditions for two labeled posets to have equal generating functions. We conclude with a classification of all equalities for labeled posets with small numbers of linear extensions.Comment: 24 pages, 19 figures. Incorporates minor changes suggested by the referees. To appear in Annals of Combinatoric

Macrofossil extinction patterns at Bay of Biscay Cretaceous-Tertiary boundary sections

Researchers examined several K-T boundary cores at Deep Sea Drilling Project (DSDP) core repositories to document biostratigraphic ranges of inoceramid shell fragments and prisms. As in land-based sections, prisms in the deep sea cores disappear well before the K-T boundary. Ammonites show a very different extinction pattern than do the inoceramids. A minimum of seven ammonite species have been collected from the last meter of Cretaceous strata in the Bay of Biscay basin. In three of the sections there is no marked drop in either species numbers or abundance prior to the K-T boundary Cretaceous strata; at the Zumaya section, however, both species richness and abundance drop in the last 20 m of the Cretaceous, with only a single ammonite specimen recovered to date from the uppermost 12 m of Cretaceous strata in this section. Researchers conclude that inoceramid bivalves and ammonites showed two different times and patterns of extinction, at least in the Bay of Biscay region. The inoceramids disappeared gradually during the Early Maestrichtian, and survived only into the earliest Late Maestrichtian. Ammonites, on the other hand, maintained relatively high species richness throughout the Maestrichtian, and then disappeared suddenly, either coincident with, or immediately before the microfossil extinction event marking the very end of the Cretaceous

Multiscale analysis of a spatially heterogeneous microscopic traffic model

The microscopic Optimal Velocity (OV) model is posed on an inhomogeneous ring-road, consisting of two spatial regimes which differ by a scaled OV function. Parameters are chosen throughout for which all uniform flows are linearly stable. The large time behaviour of this discrete system is stationary and exhibits three types of macroscopic traffic pattern, each consisting of plateaus joined together by sharp interfaces. At a coarse level, these patterns are determined by simple flow and density balances, which in some cases have non-unique solutions. The theory of characteristics for the classical Lighthill–Whitham PDE model is then applied to explain which pattern the OV model selects. A global analysis of a second-order PDE model is then performed in an attempt to explain some qualitative details of interface structure. Finally, the full microscopic model is analysed at the linear level to explain features which cannot be described by the present macroscopic approache