The Southern Hemisphere at glacial terminations: insights from the Dome C ice core

The many different proxy records from the European Project for Ice Coring in Antarctica (EPICA) Dome C ice core allow for the first time a comparison of nine glacial terminations in great detail. Despite the fact that all terminations cover the transition from a glacial maximum into an interglacial, there are large differences between single terminations. For some terminations, Antarctic temperature increased only moderately, while for others, the amplitude of change at the termination was much larger. For the different terminations, the rate of change in temperature is more similar than the magnitude or duration of change. These temperature changes were accompanied by vast changes in dust and sea salt deposition all over Antarctica. Here we investigate the phasing between a South American dust proxy (non-sea-salt calcium flux, nssCa2+), a sea ice proxy (sea salt sodium flux, ssNa+) and a proxy for Antarctic temperature (deuterium, δD). In particular, we look into whether a similar sequence of events applies to all terminations, despite their different characteristics. All proxies are derived from the EPICA Dome C ice core, resulting in a relative dating uncertainty between the proxies of less than 20 years. At the start of the terminations, the temperature (δD) increase and dust (nssCa2+ flux) decrease start synchronously. The sea ice proxy (ssNa+ flux), however, only changes once the temperature has reached a particular threshold, approximately 5°C below present day temperatures (corresponding to a δD value of −420‰). This reflects to a large extent the limited sensitivity of the sea ice proxy during very cold periods with large sea ice extent. At terminations where this threshold is not reached (TVI, TVIII), ssNa+ flux shows no changes. Above this threshold, the sea ice proxy is closely coupled to the Antarctic temperature, and interglacial levels are reached at the same time for both ssNa+ and δD. On the other hand, once another threshold at approximately 2°C below present day temperature is passed (corresponding to a δD value of −402‰), nssCa2+ flux has reached interglacial levels and does not change any more, despite further warming. This threshold behaviour most likely results from a combination of changes to the threshold friction velocity for dust entrainment and to the distribution of surface wind speeds in the dust source region.

The Civil War in Southern Sudan and Its Effect on Youth and Children

The Civil War in Sudan, which began in June 1983, has caused a numbers of social, cultural and economical problems for Sudan. Many social changes took place, not only in the southern Sudan, where the war has been fought since its inception, but also in the Sudanese Nation as a whole. In this contribution, I would like to give a short summary about the effect of the war on the Sudanese society, in general, and on youth and children, in particular. This is important, because youth and children are the future of every nation. Because the youth and children in southern Sudan are gravely affected by the current war, this article will specifically address these effects. Youth and children in the North of the country are, however, almost equally affected by the conflict. After discussing historical background of Sudan and its political and developmental condition, I will briefly summarize the social situation and the role of social work in Sudan during and after the conflict.

Decidability for some justification logics with negative introspection

Justification logics are modal logics that include justifications for the agent's knowledge. So far, there are no decidability results available for justification logics with negative introspection. In this paper, we develop a novel model construction for such logics and show that justification logics with negative introspection are decidable for finite constant specifications.

Safety climate and its association with office type and team involvement in primary care

OBJECTIVE To assess differences in safety climate perceptions between occupational groups and types of office organization in primary care. METHODS Primary care physicians and nurses working in outpatient offices were surveyed about safety climate. Explorative factor analysis was performed to determine the factorial structure. Differences in mean climate scores between staff groups and types of office were tested. Logistic regression analysis was conducted to determine predictors for a 'favorable' safety climate. RESULTS 630 individuals returned the survey (response rate, 50%). Differences between occupational groups were observed in the means of the 'team-based error prevention'-scale (physician 4.0 vs. nurse 3.8, P < 0.001). Medical centers scored higher compared with single-handed offices and joint practices on the 'team-based error prevention'-scale (4.3 vs. 3.8 vs. 3.9, P < 0.001) but less favorable on the 'rules and risks'-scale (3.5 vs. 3.9 vs. 3.7, P < 0.001). Characteristics on the individual and office level predicted favorable 'team-based error prevention'-scores. Physicians (OR = 0.4, P = 0.01) and less experienced staff (OR 0.52, P = 0.04) were less likely to provide favorable scores. Individuals working at medical centers were more likely to provide positive scores compared with single-handed offices (OR 3.33, P = 0.001). The largest positive effect was associated with at least monthly team meetings (OR 6.2, P < 0.001) and participation in quality circles (OR 4.49, P < 0.001). CONCLUSIONS Results indicate that frequent quality circle participation and team meetings involving all team members are effective ways to strengthen safety climate in terms of team-based strategies and activities in error prevention.

Amalgamation and interpolation in ordered algebras

The first part of this paper provides a comprehensive and self-contained account of the interrelationships between algebraic properties of varieties and properties of their free algebras and equational consequence relations. In particular, proofs are given of known equivalences between the amalgamation property and the Robinson property, the congruence extension property and the extension property, and the flat amalgamation property and the deductive interpolation property, as well as various dependencies between these properties. These relationships are then exploited in the second part of the paper in order to provide new proofs of amalgamation and deductive interpolation for the varieties of lattice-ordered abelian groups and MV-algebras, and to determine important subvarieties of residuated lattices where these properties hold or fail. In particular, a full description is given of all subvarieties of commutative GMV-algebras possessing the amalgamation property.

Depolymerization of malarial hemozoin: a novel reaction initiated by blood schizontocidal antimalarials

Malaria parasite digests hemoglobin and utilizes the globin part for its nutritional requirements. Heme released as a byproduct of hemoglobin degradation is detoxified by polymerization into a crystalline, insoluble pigment, known as hemozoin. We have identified a novel reaction of depolymerization of hemozoin to heme. This reaction is initiated by the interaction of blood schizonticidal antimalarial drugs with the malarial hemozoin. The reaction has been confirmed, with the purified hemozoin as well as the lysate of the malaria parasite. Pigment breakdown was studied by infrared spectroscopy, thin-layer chromatography and spectrophotometric analysis. It was complete within 2 h of drug exposure, which explains the selective sensitivity of late stages (trophozoites and schizonts) of malarial parasites loaded with the hemozoin pigment to the toxic action of these drugs. It is suggested that the failure of the parasite heme detoxification system due to this reaction results in the accumulation of toxic heme, which alone, or complexed with the antimalarial leads to the death of malaria parasite.

Schul-, Praxis- und habituelles Herrschaftswissen. Bildung ländlicher Eliten mit Blick auf die korporative Selbstverwaltung in der frühmodernen Schweiz (18. und 19. Jahrhundert)

Knowledge taught at schools, everyday skills and practical know-how. The relevancy of formation for local elites and the corporative self-government of Early Modern Switzerland Daniel Schläppi, Bern There were different kinds of rural elites in Early Modern Switzerland. The diverse parts of the country developed in very dissimilar ways politically and economically. Some regions were dominated by traditional types of agriculture. Some territories were ruled by major cities. In some of the rural Cantons like Uri, Schwyz, Unterwalden, Glarus and Zug a political elite took control over generations and practiced a cultural lifestyle comparable to the famous aristocracies in cities like Bern, Basel, Freiburg, Luzern, Solothurn and Zurich. Intense proto-industrialization formed a completely different sort of elite with strong affinities to industry and trade in other regions. Meanwhile the habitants of the valley close-by stayed farmers like their ancestors (like in Appenzell). In the most conservative parts of the country mercenary business played an important role till the very end of the Ancien Regime and even furthermore. In summery the variety of historical circumstances caused heterogeneous elites all over. Such socio-political diversity provoked a variety of educational backgrounds. I an academic understanding of the term we know only little about literacy in local rural elites. But there is strong evidence that a lively culture of reading and story-telling existed. This means that even simple countrymen seem to have been in possession of some books. The organisation and capacity of the school system is subject of controversial discussions among up to date researchers. The state of research makes us suppose that the people designed to political careers learned their essential skills not only in school but also in everyday life or on the job. Based on the fact that every community and countless public corporations managed their affairs by their own it’s evident that the local elite’s key-players had a large repertoire of techniques and skills like writing, calculating, strategic thinking or knowledge of oral tradition, old usage or important rituals. Unfortunately the historical actors left not that many sources that would tell us precisely how knowledge and know-how were transferred in former times. Hardly any private account books or common correspondence have been conserved. But a huge bunch of sources that originate from corporative self-administration shows us that most local elites were well-educated and had the necessary skills anyway. Above all other sources like for instance the «Topographische Beschreibungen» (topographic descriptions) that were initiated by the «Ökonomische Gesellschaft» of Berne since the sixties of the 18th century provide an insight into pre-modern classrooms. More important information on the historical formation-reality can be gained by the autobiography of the famous poor peasant Ulrich Bräker (1735‒1798) or some of the novels by Albert Bitzius (1797‒1854, better known as Jeremias Gotthelf). The pedagogic writings by Johann Heinrich Pestalozzi (1746‒1827) and the influences by his mentors Johann Rudolf Tschiffeli (1716‒1780) or Philipp Emanuel von Fellenberg (1771‒1884) are quite illustrative as well.

Test Facility to Study Surface-Interaction Processes for Particle Detection in Space

The Imager for Low Energetic Neutral Atoms test facility at the University of Bern was developed to investigate, characterize, and quantify physical processes on surfaces that are used to ionize neutral atoms before their analysis in neutral particle-sensing instruments designed for space research. The facility has contributed valuable knowledge of the interaction of ions with surfaces (e.g., fraction of ions scattered from surfaces and angular scattering distribution) and employs a novel measurement principle for the determination of secondary electron emission yields as a function of energy, angle of incidence, particle species, and sample surface for low particle energies. Only because of this test facility it was possible to successfully apply surface-science processes for the new detection technique for low-energetic neutral particles with energies below about 1 keV used in space applications. All successfully flown spectrometers for the detection of low-energetic neutrals based on the particle–surface interaction process use surfaces evaluated, tested, and calibrated in this facility. Many instruments placed on different spacecraft (e.g., Imager for Magnetopause-to-Aurora Global Exploration, Chandrayaan-1, Interstellar Boundary Explorer, etc.) have successfully used this technique.

Nuclear organization in the nematode C. elegans.

With its invariant cell lineage, easy genetics and small genome, the nematode Caenorhabditis elegans has emerged as one of the prime models in developmental biology over the last 50 years. Surprisingly however, until a decade ago very little was known about nuclear organization in worms, even though it is an ideal model system to explore the link between nuclear organization and cell fate determination. Here, we review the latest findings that exploit the repertoire of genetic tools developed in worms, leading to the identification of important sequences and signals governing the changes in chromatin tridimensional architecture. We also highlight parallels and differences to other model systems.

Simulation of the Impact of Dams and Fishing Weirs on Reproductive Potential of Silver-Phase American Eels in the Kennebec River Basin, Maine

I modeled the cumulative impact of hydroelectric projects with and without commercial fishing weirs and water-control dams on the production, survival to the sea, and potential fecundity of migrating female silver-phase American eels, Anguilla rostrata in the Kennebec River basin, Maine, This river basin has 22 hydroelectric projects, 73 water-control dams, and 15 commercial fishing weir sites. The modeled area included an 8,324 km(2) segment of the drainage area between Merrymeeting Bay and the upper limit of American eel distribution in the basin. One set of input,, (assumed or real values) concerned population structure (Le., population density and sex ratio changes throughout the basin, female length-class distribution, and drainage area between dams), Another set concerned factors influencing survival and potential fecundity of migrating American eels (i.e., pathway sequences through projects, survival rate per project by length-class. and length-fecundity relationship). Under baseline conditions about 402,400 simulated silver female American eels would be produced annually reductions in their numbers due to dams and weirs would reduce the realized fecundity (i.e., the number of eggs produced by all females that survived the migration). Without weirs or water-control dams, about 63% of the simulated silverphase American eels survived their freshwater spawning migration run to the sea when the survival rate at each hydroelectric dam was 9017, 40% survived at 80% survival per dam, and 18% survived at 60% survival per dam. Removing the lowermost hydroelectric dam on the Kennebec River increased survival by 6.0-7.6% for the basin. The efficient commercial weirs reduced survival to the sea to 69-76%( of what it would have been without weirs', regardless of survival rates at hydroelectric dams. Water-control dams had little impact on production in this basin because most were located in the upper reaches of tributaries. Sensitivity analysis led to the conclusion that small changes in population density and female length distribution had greater effects on survival and realized fecundity than similar changes in turbine survival rate. The latter became more important as turbine survival rate decreased. Therefore, it might be more fruitful to determine population distribution in basins of interest than to determine mortality rate at each hydroelectric project.

Orientierung. Die westliche Christenheit und das Heilige Land in der Antike

Obwohl die Vorstellung von einem irdischen Heiligen Land in den neutestamentlichen Schriften nicht belegt ist, wurde sie in der Geschichte des Christentums sehr wirkmächtig. Katharina Heyden zeigt in dieser Studie, dass nicht die explizite Rede von der terra sancta, sondern die faktische Orientierung an Palästina in unterschiedlichen Bereichen – Eschatologie, Kirchenpolitik, Hagiographie und Ikonographie – zur Sakralisierung der südlichen Levante und deren Rezeption durch westliche Christen führte. Als Bedingung der Möglichkeit einer christlichen Rede vom heiligen Land wird das „synoptische Vermögen“ herausgestellt, das sich in den Diskursen der ersten christlichen Jahrhunderte herausgebildet hat.