Tree size and fecundity influence ballistic seed dispersal of two dominant mast-fruiting species in a tropical rain forest

Seed production, seed dispersal, and seedling recruitment are integral to forest dynamics, especially in masting species. Often these are studied separately, yet scarcely ever for species with ballistic dispersal even though this mode of dispersal is common in legume trees of tropical African rain forests. Here, we studied two dominant main-canopy tree species, Microberlinia bisulcata and Tetraberlinia bifoliolata (Caesalpinioideae), in 25 ha of primary rain forest at Korup, Cameroon, during two successive masting events (2007/2010). In the vicinity of c. 100 and 130 trees of each species, 476/580 traps caught dispersed seeds and beneath their crowns c. 57,000 pod valves per species were inspected to estimate tree-level fecundity. Seed production of trees increased non-linearly and asymptotically with increasing stem diameters. It was unequal within the two species’ populations, and differed strongly between years to foster both spatial and temporal patchiness in seed rain. The M. bisulcata trees could begin seeding at 42–44 cm diameter: at a much larger size than could T. bifoliolata (25 cm). Nevertheless, per capita life-time reproductive capacity was c. five times greater in M. bisulcata than T. bifoliolata owing to former’s larger adult stature, lower mortality rate (despite a shorter life-time) and smaller seed mass. The two species displayed strong differences in their dispersal capabilities. Inverse modelling (IM) revealed that dispersal of M. bisulcata was best described by a lognormal kernel. Most seeds landed at 10–15 m from stems, with 1% of them going beyond 80 m (<100 m). The direct estimates of fecundity significantly improved the models fitted. The lognormal also described well the seedling recruitment distribution of this species in 121 ground plots. By contrast, the lower intensity of masting and more limited dispersal of the heavier-seeded T. bifoliolata prevented reliable IM. For this species, seed density as function of distance to traps suggested a maximum dispersal distance of 40–50 m, and a correspondingly more aggregated seedling recruitment pattern ensued than for M. bisulcata. From this integrated field study, we conclude that the reproductive traits of M. bisulcata give it a considerable advantage over T. bifoliolata by better dispersing more seeds per capita to reach more suitable establishment sites, and combined with other key traits they explain its local dominance in the forest. Understanding the linkages between size at onset of maturity, individual fecundity, and dispersal capability can better inform the life-history strategies, and hence management, of co-occurring tree species in tropical forests.

Shakespeare, the Middle Ages and the Luck of the British: Medievalism and National Identity in The Hollow Crown (2012)

Images of the medieval past have long been fertile soil for the identity politics of subsequent periods. Rather than “authentically” reproducing the Middle Ages, medievalism therefore usually tells us more about the concerns and ideological climate of its own time and place of origin. To dramatise the nascent nation, Shakespeare resorts to medievalism in his history plays. Centuries later, the BBC-produced television mini-serial The Hollow Crown – adapting Shakespeare’s second histories tetralogy – revamps this negotiation of national identity for the “Cultural Olympiad” in the run-up to the 2012 London Olympics. In this context of celebratory introspection, The Hollow Crown weaves a genealogical narrative consisting of the increasingly “glorious” medieval history depicted and “national” Shakespearean heritage in order to valorise 21st-century “Britishness”. Encouraging a reading of the histories as medieval history, the films construct an ostensibly inclusive, liberal-minded national identity grounded in this history. Moreover, medieval kingship is represented in distinctly sentimentalising and humanising terms, fostering emotional identification especially with the no longer ambivalent Hal/Henry V and making him an apt model for present-day British grandeur. However, the fact that the films in return marginalise female, Scottish, Irish and Welsh characters gives rise to doubts as to whether this vision of Shakespeare’s Middle Ages really is, as the producers claimed, “for everybody”.

Sex- and gender-related risk factor burden in patients with premature acute coronary syndrome

BACKGROUND Few contemporary data exist on traditional (TRF) and non-TRF (NTRF) burden in patients with premature acute coronary syndrome (ACS). METHODS Prevalence of TRFs and NTRFs were measured in 1015 young (55 years old or younger) ACS patients recruited from 26 centres in Canada, the United States, and Switzerland. Risk factors were compared across sex and family history categories, and against a sample of the general Canadian population based on the 2000-2001 Canadian Community Health Survey. The 10- and 30-year risks of cardiovascular disease (CVD) were estimated using Framingham Risk Scores. RESULTS Risk factors were more prevalent in premature ACS patients compared with the general population. Young women with a family history of coronary artery disease showed the greatest risk factor burden including TRFs of hypertension (67%), dyslipidemia (67%), obesity (53%), smoking (42%), and diabetes (33%), and NTRFs of anxiety (55%), low household income (44%), and depression (37%). The estimated median 10-year risk of CVD was 7% (interquartile range [IQR], 3%-9%) in women and 13% (IQR, 7%-17%) in men, whereas the 30-year risk of CVD was 36% (IQR, 22%-49%) in women and 44% (IQR, 31%-57%) in men. CONCLUSIONS Patients with premature ACS, especially women with a positive family history, are characterized by a very high risk factor burden that is poorly captured by 10-year risk estimates but better captured by 30-year estimates. Consideration of NTRFs and use of 30-year risk estimates might better estimate risk in young individuals and improve the prevention of premature ACS.

Weather and War – Economic and social vulnerability in Switzerland at the end of the First World War

Neutral Switzerland – not embedded in the fighting forces – yet was involved in the Great War mainly in economical terms. Since Switzerland is a landlocked country especially agriculture became an important topic of war economy in regard to food security. Until 1916 national food supply was limited but could be maintained through barter trade. In 1916 a crisis on both supply and production level occurred and led to a decline in food availability and to immense price risings causing social turmoil. This paper aims to outline the factors of vulnerability in respect of food in Switzerland during the First World War and further it will show different coping strategies that were undertaken during that time. The paper takes the work of Mario Aeby and Christian Pfister (University of Bern) into consideration that pointed out to weather anomalies during the years 1916 and 1917 aggravating the already tense food situation. Arguing for an overlap of supply and production crisis the paper focuses on agricultural and economic history including environmental impacts. Further the paper addresses the question of what makes a food system resilient to such unforeseen impacts.

Mobile Temporalities: Place, Ruination and the Dialectics of Time

In this chapter I explore the ambiguous, contradictory and often transient ways the past enters into our lives. I shed light on the interplay of mobility and temporality in the lifeworlds of two Somalis who left Mogadishu with the outbreak of the war in the 1990s. Looking into the ways they actively make sense of this crucial ‘memory-place’ (Ricoeur 2004), a place that that has been turned into a landscape of ruins and rubble, alternative understandings of memory and temporality will emerge. Instead of producing a continuum between here and there, and now and then, the stories and photographs discussed in this chapter form dialectical images – images that refuse to be woven into a coherent picture of the past. By emphasising the dialectical ways these two individuals make sense of Mogadishu’s past and presence, I am following Walter Benjamin’s cue to rethink deeply modern analytical categories such as history, memory and temporality by highlighting the brief, fragmented moments of their appearance in everyday life.

Occupational mobility chains and the role of job opportunities for upward, lateral and downward mobility in Switzerland

This paper addresses the rarely studied relationship between job vacancies and inter-firm upward, lateral, and downward status mobility in an occupationally segmented labor market, taking Switzerland as the example. To conceptualize mobility mechanisms in this type of labor market, we introduce the concept of “occupational mobility chains” and test its validity. This concept provides the backdrop for developing time-dependent measures of individual job opportunities based on Swiss Job Monitor data. We link these measures with career data taken from the Swiss Life History Study and employ event history analysis to test different propositions of the ways in which status mobility is contingent on the number and the status of vacant positions. Results support our assumption that in occupationally segmented labor markets vacant positions affect status mobility only to the degree that they are located within workers’ occupational mobility chains.