Climatic and topographic changes since the Miocene influenced the diversification and biogeography of the tent tortoise (Psammobates tentorius) species complex in Southern Africa

Background: Climatic and topographic changes function as key drivers in shaping genetic structure and cladogenic radiation in many organisms. Southern Africa has an exceptionally diverse tortoise fauna, harbouring one-third of the world’s tortoise genera. The distribution of Psammobates tentorius (Kuhl, 1820) covers two of the 25 biodiversity hotspots in the world, the Succulent Karoo and Cape Floristic Region. The highly diverged P. tentorius represents an excellent model species for exploring biogeographic and radiation patterns of reptiles in Southern Africa. Results: We investigated genetic structure and radiation patterns against temporal and spatial dimensions since the Miocene in the Psammobates tentorius species complex, using multiple types of DNA markers and niche modelling analyses. Cladogenesis in P. tentorius started in the late Miocene (11.63–5.33 Ma) when populations dispersed from north to south to form two geographically isolated groups. The northern group diverged into a clade north of the Orange River (OR), followed by the splitting of the group south of the OR into a western and an interior clade. The latter divergence corresponded to the intensifcation of the cold Benguela current, which caused western aridifcation and rainfall seasonality. In the south, tectonic uplift and subsequent exhumation, together with climatic fuctuations seemed responsible for radiations among the four southern clades since the late Miocene. We found that each clade occurred in a habitat shaped by diferent climatic parameters, and that the niches difered substantially among the clades of the northern group but were similar among clades of the southern group. Conclusion: Climatic shifts, and biome and geographic changes were possibly the three major driving forces shaping cladogenesis and genetic structure in Southern African tortoise species. Our results revealed that the cladogenesis of the P. tentorius species complex was probably shaped by environmental cooling, biome shifts and topographic uplift in Southern Africa since the late Miocene. The Last Glacial Maximum (LGM) may have impacted the distribution of P. tentorius substantially. We found the taxonomic diversify of the P. tentorius species complex to be highest in the Greater Cape Floristic Region. All seven clades discovered warrant conservation attention, particularly Ptt-B–Ptr, Ptt-A and Pv-

The Tourist Offer of the Destination in an Experience Logic Perspective

The aim of the chapter is to propose an application of the experience logic and, in particular, the theatrical model to organize the tourist offer for the destination. Assuming the prospect of selling experiences, it emerges that, among the various factors needed for a destination to fall within the theatrical model, there must be the indispensable presence of a director (governing body in a systemic approach), to which we refer in our proposal for possible tourist destination market-oriented management tools. According to the theatrical model inspired by Pine and Gilmore, in which they underline that each business can be considered a show business, in order to be wholly efficient, the marketing activities must be geared toward the various internal (cast) and external subjects within the organizational system, whether it is a company or a destination. In other words, it is a question of adopting an integrated managerial perspective that is widely diffused organization-wide and culturally holistic. What is to be avoided is the logic of focusing the marketing only on the final client, thereby falling into a near-sighted approach that underestimates the importance of truly satisfying an audience when all of the theater components have worked together well. Indeed, concentrating exclusively on the external consumer means ignoring the fact that, in a tourist system, there are stakeholders (internal clients, distributes, suppliers, financial backers, public institutions, mass media, etc.) whose complete satisfaction is an indispensable condition for satisfying the final client and for long-term competitive success. We propose applying the experience concept and the theater model to tourist destinations with all due conceptual caution, aware of the limitations inherent in both theory and managerial actions, in undertaking to shift into terri27 torial contexts paradigms and tools that were developed with reference to organi2829 zational systems

Perceptions of Efficacy, Control and Risk: A Theory of Mixed Control

We prove a multivariable elliptic analogue of Jackson’s 8W7 summation formula, which was recently conjectured by S. O. Warnaar

Alternative pathways for phosphonate metabolism in thermophilic cyanobacteria from microbial mats

Synechococcus sp. represents an ecologically diverse group of cyanobacteria found in numerous environments, including hot-spring microbial mats, where they are spatially distributed along thermal, light and oxygen gradients. These thermophiles engage in photosynthesis and aerobic respiration during the day, but switch to fermentative metabolism and nitrogen fixation at night. The genome of Synechococcus OS-B′, isolated from Octopus Spring (Yellowstone National Park) contains a phn gene cluster encoding a phosphonate (Phn) transporter and a C–P lyase. A closely related isolate, Synechococcus OS-A, lacks this cluster, but contains genes encoding putative phosphonatases (Phnases) that appear to be active only in the presence of the Phn substrate. Both isolates grow well on several different Phns as a sole phosphorus (P) source. Interestingly, Synechococcus OS-B′ can use the organic carbon backbones of Phns for heterotrophic growth in the dark, whereas in the light this strain releases organic carbon from Phn as ethane or methane (depending on the specific Phn available); Synechococcus OS-A has neither of these capabilities. These differences in metabolic strategies for assimilating the P and C of Phn by two closely related Synechococcus spp. are suggestive of niche-specific constraints in the evolution of nutrient assimilation pathways and syntrophic relationships among the microbial populations of the hot-spring mats. Thus, it is critical to evaluate levels of various P sources, including Phn, in thermally active habitats and the potential importance of these compounds in the biogeochemical cycling of P and C (some Phn compounds also contain N) in diverse terrestrial environments

Perceptions of Efficacy, Control and Risk: A Theory of Mixed Control

Based on the aggregated insights of the existing theories related to multiple sources of efficacy and locus of control, we introduce the theory of mixed control, a model of compound-risk perception. This theory considers outcome expectancies as being composed of expectancies regarding three distinct sources of risk (self, others, and chance). This reflects that entrepreneurship is a complex and dynamic activity, involving multiple sources of risk. Beliefs about the efficacy of these elements are weighted by the degree to which these elements are perceived to control the outcome. The interaction of efficacy and control beliefs is therefore at the core of our theory. Further, we discuss that risks are not only subjectively perceived but can be endogenous and depend on future decisions and actions of the entrepreneur