The Relationship of Catalase Activity to the Trade-Off Between Reproduction and Lifespan in the Giant Waterbug, Belostoma flumineum

Senescence is the process by which organisms age and ultimately die. Life history theory suggests that the allocation of energy into growth and reproduction is necessarily associated with a decrease in energy available for the maintenance of the soma. Many studies have shown that early or increased rates of reproduction are often correlated with a decrease in longevity, but few studies have investigated physiological correlates to this event. Catalase is an enzyme involved in the removal of oxygen free radicals implicated in damaging cellular components that contribute to senescence. A decrease in catalase activity with age could increase the organism\u27s maintenance cost and lead to an increased rate of senescence. This study investigated the possibility that changes in catalase activity are related to the energy trade-off between reproduction and longevity in the giant waterbug, Belostoma flumineum. This species is a good model for this type of investigation because both males and females contribute a significant amount of parental investment. Waterbugs were collected as fifth instar nymphs and maintained under controlled laboratory conditions. Males and females were randomly allocated to either virgin or breeder reproductive treatments. Waterbugs were assayed for catalase activity at ages of 10, 60, 100, and 150 days. Catalase activity/ g bug was shown to increase with chronological age in male and female virgins, but not in breeders of either sex; most of this change was early in life (0-60 days). Virgin bugs also had higher catalase activity I g bug than those that were allowed to breed. This might suggest that waterbugs that breed are less protected from free radical damage than virgins, and could help explain the shortened life span of breeders relative to virgins

Changes in trabecular bone, hematopoiesis and bone marrow vessels in aplastic anemia, primary osteoporosis, and old age

Retrospective histologic analyses of bone biopsies and of post mortem samples from normal persons of different age groups, and of bone biopsies of age- and sex-matched groups of patients with primary osteoporosis and aplastic anemia show characteristic age dependent as well as pathologic changes including atrophy of osseous trabeculae and of hematopoiesis, and changes in the sinusoidal and arterial capillary compartments. These results indicate the possible role of a microvascular defect in the pathogenesis of osteoporosis and aplastic anemia

Precision spectroscopy of pionic 1s states of Sn nuclei and evidence for partial restoration of chiral symmetry in the nuclear medium

Deeply bound 1s states of $\pi^-$ in $^{115,119,123}$Sn were preferentially observed using the Sn($d$,$^3$He) pion-transfer reaction under the recoil-free condition. The 1s binding energies and widths were precisely determined, and were used to deduce the isovector parameter of the s-wave pion-nucleus potential to be $b_1 =-0.115\pm 0.007 ~m_{\pi}^{-1}$. The observed enhancement of $|b_1|$ over the free $\pi N$ value ($b_1^{\rm free}/b_1 = 0.78 \pm 0.05$) indicates a reduction of the chiral order parameter, $f^{*}_{\pi} (\rho)^2/f_{\pi}^2 \approx 0.64$, at the normal nuclear density, $\rho = \rho_0$.Comment: 4 pages including 3 postscript figures, RevTeX 4 with multirow.sty, submitted to Physical Review Letter

Synchronous timing of return to breeding sites in a long-distance migratory seabird with ocean-scale variation in migration schedules

Background Migratory birds generally have tightly scheduled annual cycles, in which delays can have carry-over effects on the timing of later events, ultimately impacting reproductive output. Whether temporal carry-over effects are more pronounced among migrations over larger distances, with tighter schedules, is a largely unexplored question. Methods We tracked individual Arctic Skuas Stercorarius parasiticus, a long-distance migratory seabird, from eight breeding populations between Greenland and Siberia using light-level geolocators. We tested whether migration schedules among breeding populations differ as a function of their use of seven widely divergent wintering areas across the Atlantic Ocean, Mediterranean Sea and Indian Ocean. Results Breeding at higher latitudes led not only to later reproduction and migration, but also faster spring migration and shorter time between return to the breeding area and clutch initiation. Wintering area was consistent within individuals among years; and more distant areas were associated with more time spent on migration and less time in the wintering areas. Skuas adjusted the period spent in the wintering area, regardless of migration distance, which buffered the variation in timing of autumn migration. Choice of wintering area had only minor effects on timing of return at the breeding area and timing of breeding and these effects were not consistent between breeding populations. Conclusion The lack of a consistent effect of wintering area on timing of return between breeding areas indicates that individuals synchronize their arrival with others in their population despite extensive individual differences in migration strategies

The Lore of Low Methane Livestock:Co-Producing Technology and Animals for Reduced Climate Change Impact

Methane emissions from sheep and cattle production have gained increasing profile in the context of climate change. Policy and scientific research communities have suggested a number of technological approaches to mitigate these emissions. This paper uses the concept of co-production as an analytical framework to understand farmers’ evaluation of a 'good animal’. It examines how technology and sheep and beef cattle are co-produced in the context of concerns about the climate change impact of methane. Drawing on 42 semi-structured interviews, this paper demonstrates that methane emissions are viewed as a natural and integral part of sheep and beef cattle by farmers, rather than as a pollutant. Sheep and beef cattle farmers in the UK are found to be an extremely heterogeneous group that need to be understood in their specific social, environmental and consumer contexts. Some are more amenable to appropriating methane reducing measures than others, but largely because animals are already co-constructed from the natural and the technical for reasons of increased production efficiency

Public opinion on energy crops in the landscape: considerations for the expansion of renewable energy from biomass

Public attitudes were assessed towards two dedicated biomass crops – Miscanthus and Short Rotation Coppice (SRC), particularly regarding their visual impacts in the landscape. Results are based on responses to photographic and computer-generated images as the crops are still relatively scarce in the landscape. A questionnaire survey indicated little public concern about potential landscape aesthetics but more concern about attendant built infrastructure. Focus group meetings and interviews indicated support for biomass end uses that bring direct benefits to local communities. Questions arise as to how well the imagery used was able to portray the true nature of these tall, dense, perennial plants but based on the responses obtained and given the caveat that there was limited personal experience of the crops, it appears unlikely that wide-scale planting of biomass crops will give rise to substantial public concern in relation to their visual impact in the landscape

Non-state nations: Structure, rescaling, and the role of territorial policy communities, illustrated by the cases of Wales and Sardinia

This paper explores the role of non-state nations’ identity and agency with regard to relations with their host nation states. The particular focus here is on the means by which such regions might express their individuality. To this end, we employ a comparative case study analysis of two non-state nations with a range of differing yet in other ways similar qualities – namely Wales (UK) and Sardinia (Italy). We suggest that this is a valuable exercise, allowing as it does for the exploring of evidence ‘on the ground’ of the processes involved. The conceptual rationale for the paper is provided by new regionalism – regions as actors beyond the nation state. Following this, the idea of the ‘territorial policy community’ is presented as a point of departure, with the scope of the paper being to develop a diachronic framework for regional change. Given the focus on identity and interest articulation, the role of regional political parties is a particular subject of the empirical investigation, with non-state nations and nation states linked by opportunistic relationships based on political and electoral support. We then consider what this might mean with regard to the capacity of non-state nations to build on the past to successfully negotiate future policy-making agendas. Finally, we reflect on the limitations of the study, and consider the implications of its findings for further research agendas