Seedling resistance, tolerance and escape from herbivores: insights from co-dominant canopy tree species in a resource-poor African rain forest

* Although plants can reduce the impacts of herbivory in multiple ways, these defensive traits are often studied in isolation and an understanding of the resulting strategies is incomplete. * In the study reported here, empirical evidence was simultaneously evaluated for the three main sets of traits available to plants: (i) resistance through constitutive leaf traits, (ii) tolerance to defoliation and (iii) escape in space, for three caesalpiniaceous tree species Microberlinia bisulcata, Tetraberlinia bifoliolata and T. korupensis, which co-dominate groves within the lowland primary rain forest of Korup National Park (Cameroon). * Mesh cages were placed around individual wild seedlings to exclude insect herbivores at 41 paired canopy gap and understorey locations. After following seedling growth and survival for c. 2 years, caged and control treatments were removed, leaves harvested to determine nutrient and phenolic concentrations, leaf mass per area estimated, and seedling performance in gaps followed for a further c. 2 years to quantify tolerance to the leaf harvesting. * The more nutrient-rich leaves of the weakly shade-tolerant M. bisulcata were damaged much more in gaps than the two strongly shade-tolerant Tetraberlinia species, which had higher leaf mass per area and concentrations of total phenols. Conversely, the faster-growing M. bisulcata was better able to tolerate defoliation in terms of height growth (reflushing capacity), but not at maintaining overall leaf numbers, than the other two species. * Across gaps, insect-mediated Janzen–Connell effects were most pronounced for M. bisulcata, less so for T. korupensis, and not detectable for T. bifoliolata. The three species differed distinctly in their secondary metabolic profiles. * Taken together, the results suggested a conceptual framework linking the three sets of traits, one in which the three co-dominant species adopt different strategies towards herbivore pressure depending on their different responses to light availability. This study is one of the first in a natural forest ecosystem to examine resistance to, tolerance of, and escape from herbivory among a group of co-occurring tropical tree species.

Disentangling human tolerance and resistance against HIV.

In ecology, "disease tolerance" is defined as an evolutionary strategy of hosts against pathogens, characterized by reduced or absent pathogenesis despite high pathogen load. To our knowledge, tolerance has to date not been quantified and disentangled from host resistance to disease in any clinically relevant human infection. Using data from the Swiss HIV Cohort Study, we investigated if there is variation in tolerance to HIV in humans and if this variation is associated with polymorphisms in the human genome. In particular, we tested for associations between tolerance and alleles of the Human Leukocyte Antigen (HLA) genes, the CC chemokine receptor 5 (CCR5), the age at which individuals were infected, and their sex. We found that HLA-B alleles associated with better HIV control do not confer tolerance. The slower disease progression associated with these alleles can be fully attributed to the extent of viral load reduction in carriers. However, we observed that tolerance significantly varies across HLA-B genotypes with a relative standard deviation of 34%. Furthermore, we found that HLA-B homozygotes are less tolerant than heterozygotes. Lastly, tolerance was observed to decrease with age, resulting in a 1.7-fold difference in disease progression between 20 and 60-y-old individuals with the same viral load. Thus, disease tolerance is a feature of infection with HIV, and the identification of the mechanisms involved may pave the way to a better understanding of pathogenesis.

The Personal Foundations of Political Tolerance towards Immigrants

In this paper, we expand previous research on the psychological foundations of attitudes towards immigrants by evaluating the role of the Big Five personality traits with regard to the formation of political tolerance. Following the literature, we elaborate tolerance as a sequential concept of rejection and acceptance to uncover differentiating effects of personality on both immigrant-specific prejudices as well as on the assignment of the right to vote as a pivotal political privilege to this group. Using a representative sample of the Swiss population, with its distinctive history related to the immigration issue, our two-step Heckman selection models reveal that extroverts and people who score low in agreeableness exhibit negative attitudes towards immigrants. At the same time, only openness to experience is significantly connected to the likeliness of granting immigrants the right to vote.

Teaching Tolerance? Associational Diversity and Tolerance Formation

Tolerance is a basic democratic principle that helps civil societies cope with rising levels of diversity stemming from increased immigration and individualism. During the last decade the question of how tolerance may be fostered has dominated debates in public and academic spheres. In this article, a closer look is taken at how associational diversity relates to the formation of tolerance and the importance of associations as schools of tolerance are evaluated. The main theoretical argument follows contact theory, wherein regular and enduring contact in diverse settings reduces prejudice and thereby increases an individual’s tolerance toward objectionable groups. The empirical findings reveal a positive relationship between associational diversity and tolerance. It is observed, however, that the duration of active engagement in associations reduces this positive relation between diversity and tolerance. Accordingly, these results challenge the notion that associations serve as schools of tolerance in the long run.

The present state of the Jews : wherein is contained an exact account of their customs, secular and religious ; to which is annexed a summary discourse of the Misna, Talmud, and Gemara

by L. Addison

Addresses on homely and religious subjects, delivered before the children of the Hebrew Orphan Asylum

by Hermann Baar

Patterns of Religious Education Policy in Switzerland. The Long Arm of Distanced Christians?

In spite of its different cantonal jurisdictions and traditions, the development of religious education in Switzerland over the past decade has taken a common direction: the state has assumed a more active role in the field of religious education in public (state-run) schools. In this article, we ask the question: How do key social actors interpret these reforms and how do these interpretations relate to the social structure of religion in Switzerland, in particular with respect to the majority category of the so-called distanced Christians? Drawing on qualitative interviews with members of the schools’ teaching staff, school administrators, and church representatives, the article highlights a dominant interpretative pattern that frames the socially accepted representation of religion in public schools. Thus, rather than addressing the pedagogical dimension of religious education, we discuss the significance of this pattern for the debate on the public presence of religion in Switzerland and Europe.

Optical Tolerance Analysis of the Multi-Beam Limb Viewing Instrument STEAMR

In this paper, we report on an optical tolerance analysis of the submillimeter atmospheric multi-beam limb sounder, STEAMR. Physical optics and ray-tracing methods were used to quantify and separate errors in beam pointing and distortion due to reflector misalignment and primary reflector surface deformations. Simulations were performed concurrently with the manufacturing of a multi-beam demonstrator of the relay optical system which shapes and images the beams to their corresponding receiver feed horns. Results from Monte Carlo simulations show that the inserts used for reflector mounting should be positioned with an overall accuracy better than 100 μm (~ 1/10 wavelength). Analyses of primary reflector surface deformations show that a deviation of magnitude 100 μm can be tolerable before deployment, whereas the corresponding variations should be less than 30 μm during operation. The most sensitive optical elements in terms of misalignments are found near the focal plane. This localized sensitivity is attributed to the off-axis nature of the beams at this location. Post-assembly mechanical measurements of the reflectors in the demonstrator show that alignment better than 50 μm could be obtained.

Semi-dwarfism and lodging tolerance in tef (Eragrostis tef) is linked to a mutation in the α-Tubulin 1 gene

Genetic improvement of native crops is a new and promising strategy to combat hunger in the developing world. Tef is the major staple food crop for approximately 50 million people in Ethiopia. As an indigenous cereal, it is well adapted to diverse climatic and soil conditions; however, its productivity is extremely low mainly due to susceptibility to lodging. Tef has a tall and weak stem, liable to lodge (or fall over), which is aggravated by wind, rain, or application of nitrogen fertilizer. To circumvent this problem, the first semi-dwarf lodging-tolerant tef line, called kegne, was developed from an ethyl methanesulphonate (EMS)-mutagenized population. The response of kegne to microtubule-depolymerizing and -stabilizing drugs, as well as subsequent gene sequencing and segregation analysis, suggests that a defect in the α-Tubulin gene is functionally and genetically tightly linked to the kegne phenotype. In diploid species such as rice, homozygous mutations in α-Tubulin genes result in extreme dwarfism and weak stems. In the allotetraploid tef, only one homeologue is mutated, and the presence of the second intact α-Tubulin gene copy confers the agriculturally beneficial semi-dwarf and lodging-tolerant phenotype. Introgression of kegne into locally adapted and popular tef cultivars in Ethiopia will increase the lodging tolerance in the tef germplasm and, as a result, will improve the productivity of this valuable crop.

The Jew's struggle for religious and civil liberty in Maryland

by E. Milton Altfeld

American Judaism : the religion and religious institutions of the jewish people in the United States ; a historical survey

by Joseph Leiser

Collingwood on religious atonement

R. G. Collingwood’s philosophical analysis of religious atonement as a dialectical process of mortal repentance and divine forgiveness is explained and criticized. Collingwood’s Christian concept of atonement, in which Christ TeX the Atonement (and also TeX the Incarnation), is subject in turn to another kind of dialectic, in which some of Collingwood’s leading ideas are first surveyed, and then tested against objections in a philosophical evaluation of their virtues and defects, strengths and weaknesses. Collingwood’s efforts to synthesize objective and subjective aspects of atonement, and his proposal to solve the soteriological problem as to why God becomes flesh, as a dogma of some Christian belief systems, is finally exposed in adversarial exposition as inadequately supported by one of his main arguments, designated here as Collingwood’s Dilemma. The dilemma is that sin is either forgiven or unforgiven by God. If God forgives sin, then God’s justice is lax, whereas if God does not forgive sin, then, also contrary to divine nature, God lacks perfect loving compassion. The dilemma is supposed to drive philosophy toward a concept of atonement in which the sacrifice of Christ is required in order to absolve God of the lax judgment objection. God forgives sin only when the price of sin is paid, in this case, by the suffering and crucifixion of God’s avatar. The dilemma can be resolved in another way than Collingwood considers, undermining his motivation for synthesizing objective and subjective facets of the concept of atonement for the sake of avoiding inconsistency. Collingwood is philosophically important because he asks all the right questions about religious atonement, and points toward reasonable answers, even if he does not always deliver original philosophically satisfactory solutions.