A Chiton Uses Aragonite Lenses to Form Images

SummaryHundreds of ocelli are embedded in the dorsal shell plates of certain chitons [1]. These ocelli each contain a pigment layer, retina, and lens [2], but it is unknown whether they provide chitons with spatial vision [3]. It is also unclear whether chiton lenses are made from proteins, like nearly all biological lenses, or from some other material [4]. Electron probe X-ray microanalysis and X-ray diffraction revealed that the chiton Acanthopleura granulata has the first aragonite lenses ever discovered. We found that these lenses allow A. granulata's ocelli to function as small camera eyes with an angular resolution of about 9°–12°. Animals responded to the sudden appearance of black, overhead circles with an angular size of 9°, but not to equivalent, uniform decreases in the downwelling irradiance. Our behavioral estimates of angular resolution were consistent with estimates derived from focal length and receptor spacing within the A. granulata eye. Behavioral trials further indicated that A. granulata's eyes provide the same angular resolution in both air and water. We propose that one of the two refractive indices of the birefringent chiton lens places a focused image on the retina in air, whereas the other does so in water

Ku, kalv og diing - Økobonden sine erfaringar.

Only poster shown, no paper in the proceedings. Tips ved separasjon • Separasjon med kontakt men ikkje diing • Gradvis nedtrapping av diing, gi surmjølk i tillegg • Nedtrapping av samvær • Gi kalven ei flaske mjølk før den får kome saman med kua. • Avvend fleire kalver samtidi

Exploring the Information Base Needed for Sustainable Management of Rangeland Resources for Improved Livelihoods

Pastoralism is one of the most sustainable production systems worldwide and plays a major role in safeguarding ecosystem services and biodiversity in rangelands. The unique biological and cultural diversity of rangelands contributes to goods, services and knowledge that benefit humans also beyond the herding communities. Yet data currently available on grassland, forestry, agriculture and livestock are inadequate for informing policymaking on rangeland-based livestock systems. A review of global environmental assessments, online databases, peer-reviewed literature and international project documents showed that available information seldom disaggregates rangelands from other ecosystems or pastoralists from other rural dwellers. Few peer-reviewed publications address pastoral and rangeland issues combined. While some international projects present contextualised information on cases of pastoralism and rangelands, most do not share the data on their websites. A challenge encountered when seeking information is the inconsistency in defining pastoralists and rangelands. Estimates of the total number of pastoralists vary from 22 million to over half a billion; estimates of area covered by rangelands vary from 18% to 80% of the world’s land surface. The variation in definitions and lack of disaggregation of data lead to significant knowledge gaps on the condition and trends of pastoralism and rangelands. These therefore tend to be devalued. Underrating benefits of livestock mobility and inaccurate data on rangeland degradation could cause governments to blame and dismantle traditionally sustainable pastoral systems – in other words, ‘fix’ something that’s not broken. Without good data on pastoralists and rangelands, the impacts of current policies on these livelihoods and ecosystems cannot be assessed, and sustainable use and management of rangelands for improved livelihoods may be hindered. Improving the information base is high on the agenda of the initiative for an International Year of Rangelands and Pastoralists to increase global awareness of the importance of rangelands and pastoralists for livelihoods and healthy ecosystems

Socio-economic and lifestyle factors associated with the risk of prostate cancer

International and interethnic differences in prostate cancer incidence suggest an environmental aetiology, and lifestyle and socio-economic factors have been studied, but with divergent results. Information on a cohort of 22 895 Norwegian men aged 40 years and more was obtained from a health examination and two self-administered questionnaires. Information on incident cases of prostate cancer was made available from the Cancer Registry. We used the Cox proportional hazards model to calculate incidence rate ratios as estimates of the relative risk (RR) with 95% confidence interval (CI). Reported P -values are two-sided. During a mean follow-up of 9.3 years, 644 cases were diagnosed. Risk was elevated among men in occupations of high compared to low socio-economic status (RR = 1.30; 95% CI 1.05–1.61), and among men with high education compared to the least educated (RR = 1.56; 95% CI 1.11–2.19). A RR of 1.56 (95% CI 0.97–2.44) suggests a higher risk among divorced or separated men, compared with married men. We also found indications of a weak negative association with leisure-time physical activity (RR = 0.80; 95% CI 0.62–1.03 for high vs low activity), a weak positive association with increasing number of cigarettes (P = 0.046), while alcohol consumption was not related to the risk of prostate cancer. These results show that high socio-economic status is associated with increased risk of prostate cancer, and that divorced or separated men might be at higher risk than married men. Data from this study also indicate that high levels of physical activity may reduce prostate cancer risk. © 2000 Cancer Research Campaig

Meddelelser

Intet resum

Meddelelser

Intet resum

Developing a Glossary of People-Focused Terms Related to Rangelands and Grasslands

Excellent glossaries on rangelands and grasslands have been developed by the Society for Range Management (SRM), the International Grassland Congress (IGC) and the International Rangeland Congress (IRC). However, these are largely confined to biophysical and technical terminology and contain very few concepts referring to social, institutional and policy aspects of using rangelands and grasslands. After the 10th IRC in Saskatoon, Canada, in 2016, an informal group started to develop a glossary of such “people-focused” terms. The short and non-academic definitions are meant to improve communication and understanding by users/practitioners in rangeland and grassland management, policymakers, teachers, students, journalists and the general public. The glossary focuses on terms in common international use in rangeland management and includes terminology referring to rangelands/grasslands users (e.g. pastoralists, agropastoralists, hunters and gatherers) and to how they organise the use and management of rangeland resources (e.g. common property rights, resource access rights, herding contracts, transhumance and other forms of mobility). More general terms in social sciences are not included, as the debates about their meanings are well covered in the conventional social science literature. Thus far, the glossary is in English only. It is hoped that people working on rangelands and pastoralism in other countries will translate it into other languages and adapt it with area- and language-specific terminology. The definitions in the glossary are intended to fill an existing gap relatively quickly. Previous experience of the SRM, IRC and IGC showed that developing a comprehensive glossary takes several years. The current version of the glossary will doubtless be revised when a more systematic effort is made to define socio-institutional terms related to rangelands and grasslands. In any case, further revisions will be made as concepts evolve and new ones arise, as was the case with the technical glossaries of the SRM, IGC and IRC