Distribution of interstitial stem cells in Hydra

The distribution of interstitial stem cells along the Hydra body column was determined using a simplified cloning assay. The assay measures stem cells as clone-forming units (CFU) in aggregates of nitrogen mustard inactivated Hydra tissue. The concentration of stem cells in the gastric region was uniform at about 0.02 CFU/epithelial cell. In both the hypostome and basal disk the concentration was 20-fold lower. A decrease in the ratio of stem cells to committed nerve and nematocyte precursors was correlated with the decrease in stem cell concentration in both hypostome and basal disk. The ratio of stem cells to committed precursors is a sensitive indicator of the rate of self-renewal in the stem cell population. From the ratio it can be estimated that <10% of stem cells self-renew in the hypostome and basal disk compared to 60% in the gastric region. Thus, the results provide an explanation for the observed depletion of stem cells in these regions. The results also suggest that differentiation and self-renewal compete for the same stem cell population

Reading (in/and) Miranda

"Australian fiction, like that of all nations, is written, published, received and read in the context of a literary canon, both national and transnational. In regards to women's fiction in Australia, this canon is predominantly composed of writers from two particular eras: authors of the nineteenth and early twentieth centuries (like Henry Handel Richardson, Miles Franklin, Katharine Susannah Prichard and Christina Stead) and women writers who came to prominence during the 1980s (like Helen Garner, Kate Grenville, Elizabeth Jolley, Barbara Hanrahan, Jessica Anderson and Beverley Farmer ... The second-wave feminist movement was responsible for the creation of this dual canon: in the first case, due to a desire to recover and reclaim women writers of the past, and in the second, due to a desire to celebrate and explore contemporary Australian women's fiction. Indeed, it is the preoccupation of second-wave feminism with uncovering and celebrating women's occluded stories that underlies the current critical focus on realist and experiential aspects of Australian women's fiction ... Among those whose work has been occluded by the critical attention given to the canonical figures of Australian women's writing, Wendy Scarfe is indicative in various ways.

Crossing numbers of composite knots and spatial graphs

We study the minimal crossing number $c(K_{1}\# K_{2})$ of composite knots $K_{1}\# K_{2}$, where $K_1$ and $K_2$ are prime, by relating it to the minimal crossing number of spatial graphs, in particular the $2n$-theta curve $\theta_{K_{1},K_{2}}^n$ that results from tying $n$ of the edges of the planar embedding of the $2n$-theta graph into $K_1$ and the remaining $n$ edges into $K_2$. We prove that for large enough $n$ we have $c(\theta_{K_1,K_2}^n)=n(c(K_1)+c(K_2))$. We also formulate additional relations between the crossing numbers of certain spatial graphs that, if satisfied, imply the additivity of the crossing number or at least give a lower bound for $c(K_1\# K_2)$.Comment: 20 pages, 11 figures, changes from version1: added Lemma 5.2 and corrected mistake in Proposition 5.3, improved quality of figure

'We're not truckin' around': On and off-road in Samuel Wagan Watson's Smoke Encrypted Whispers

Cars and roads traverse the poetry of Samuel Wagan Watson, a self-identified Aboriginal man of Bundjalung, Birri Gubba, German and Irish ancestry. The narrator/s of the poems in 'Smoke Encrypted' Whispers are repeatedly on the road or beside it, and driving is employed as a metaphor for everything from addiction and memory to the search for love. Road kill litters the poems, while roads come to life, cars become men, and men have 'gas tanks that can't see empty'. Watson's poetry has received significant critical attention and acclaim: his 'haunting, uncanny, layered poetics of history' and depiction of 'colonial degradation' have been explored, and his poems-including those featuring cars and roads-have been analysed in relation to such themes as the sacred, locatedness, and creative processes. Given the extent to which cars and roads dominate Watson's poetry, it is notable, however, that his use of both to explore and resist 'colonial degradation' has not received sustained attention

Tooth characters of protohippine horses with special reference to species from the Merychippus zone, California

The critical review of equine tooth characters attempted in this paper is the result of a study of the protohippine horses obtained from the Merychippus Zone of the north Coalinga district, California. During the conduct of extensive excavations in this zone since 1928 by the California Institute, more than two thousand teeth of the genus Merychippus have been collected. In addition to the types represented by the equine material, a number of associated land mammals have been secured. The faunal list, which includes some fifteen species, suggests that this locality occupies a stratigraphic position approximately late middle Miocene in age. The variation displayed in the dental characters of the merychippine material from the Merychippus Zone necessitated comparisons with cheek-teeth of Equidae from practically all of the Miocene formations furnishing vertebrate remains in the Pacific Coast and Great Basin Provinces. A comprehensive study of these collections clearly demonstrates that many of the cheek-tooth characters employed in the description of type specimens of fossil horses are variable to an extent which renders them unreliable in a determination of species. The variation of these characters within a large collection also indicates that it is possible for teeth referable to a particular species to have a wider stratigraphic range than has been hitherto appreciated. The conclusion is reached that the presence of a species has less value in reaching an age determination of the strata in which it occurs than evidence furnished by an association of several species

European Climate Policy: Burden Sharing after 2012

Regardless of whether or not the Kyoto Protocol enters into force, the EU may decide to set itself a long-term greenhouse gas emission target and thus to continue its leadership role in international climate policy. As for the first commitment period of the Kyoto Protocol, the EU may decide on a burden-sharing agreement as an integral part of such a long-term climate policy. Against this background I analyse three different options to distribute an overall budget of emission entitlements until 2042 among the member states of an enlarged EU. It is shown who wins and who loses with regard to compliance costs. As the member states' attitudes towards the different approaches are likely to depend on the relative attractiveness of the allocation options, a relevance threshold is introduced which may help to predict and understand the complexity of future climate negotiations in Europe.accession countries, allocation of GHG emission entitlements, burden sharing, European climate policy, EU-enlargement, future commitment periods, Environmental Economics and Policy, Q25, Q28,