Dimensions of Global Change in African Mountains: The Example of Mount Kenya

This paper discusses the effects of global change in African mountains, with the example of Mount Kenya. The geographical focus is the northwestern, semi-arid foot zone of the mountain (Laikipia District). Over the past 50 years, this area has experienced rapid and profound transformation, the respective processes of which are all linked to global change. The main driving forces behind these processes have been political and economic in nature. To these an environmental change factor has been added in recent years – climate change. After introducing the area of research, the paper presents three dimensions of global change that are manifested in the region and largely shape its development: Socio-political change, economic change, environmental change. For the regions northwest of Mount Kenya, climate models predict important changes in rainfall distribution that will have a profound impact on freshwater availability and management. The results presented here are based on research undertaken northwest of Mount Kenya within the framework of a series of long-term Kenyan-Swiss research programmes that began in the early 1980s.

Efficiency of frost-cracking processes through space and time: An example from the eastern Italian Alps

It is widely accepted that climate has a strong impact and exerts important feedbacks on erosional processes and sediment transport mechanisms. However, the extent at which climate influences erosion is still a matter of debate. In this paper we test whether frost-cracking processes and related temperature variations can influence the sediment production and surface erosion in a small catchment situated in the eastern Italian Alps. To this extent, we first present a geomorphic map of the region that we complement with published 10Be-based denudation rates. We then apply a preexisting heat-flow model in order to analyze the variations of the frost-cracking intensity (FCI) in the study area, which could have controlled the sediment production in the basin. Finally, we compare the model results with the pattern of denudation rates and Quaternary deposits in the geomorphic map. The model results, combined with field observations, mapping, and quantitative geomorphic analyses, reveal that frost-cracking processes have had a primary role in the production of sediment where the intensity of sediment supply has been dictated and limited by the combined effect of temperature variations and conditions of bedrock preservation. These results highlight the importance of a yet poorly understood process for the production of sediment in mountain areas.

P-T-t estimation of syn-kinematic strain in low-grade quartz-feldspar bearing rocks using thermodynamic modeling and 40Ar/39Ar dating techniques: example of the Plan-de-Phasy shear zone unit (Briançonnais Zone, Western Alps)

Pressure–Temperature–time (P–T–t) estimates of the syn-kinematic strain at the peak-pressure conditions reached during shallow underthrusting of the Briançonnais Zone in the Alpine subduction zone was made by thermodynamic modelling and 40Ar/39Ar dating in the Plan-de-Phasy unit (SE of the Pelvoux Massif, Western Alps). The dated phengite minerals crystallized syn-kinematically in a shear zone indicating top-to-the-N motion. By combining X-ray mapping with multi-equilibrium calculations, we estimate the phengite crystallization conditions at 270 ± 50 °C and 8.1 ± 2 kbar at an age of 45.9 ± 1.1 Ma. Combining this P–T–t estimate with data from the literature allows us to constrain the timing and geometry of Alpine continental subduction. We propose that the Briançonnais units were scalped on top of the slab during ongoing continental subduction and exhumed continuously until collision.

Sample size considerations using mathematical models: an example with Chlamydia trachomatis infection and its sequelae pelvic inflammatory disease.

BACKGROUND The success of an intervention to prevent the complications of an infection is influenced by the natural history of the infection. Assumptions about the temporal relationship between infection and the development of sequelae can affect the predicted effect size of an intervention and the sample size calculation. This study investigates how a mathematical model can be used to inform sample size calculations for a randomised controlled trial (RCT) using the example of Chlamydia trachomatis infection and pelvic inflammatory disease (PID). METHODS We used a compartmental model to imitate the structure of a published RCT. We considered three different processes for the timing of PID development, in relation to the initial C. trachomatis infection: immediate, constant throughout, or at the end of the infectious period. For each process we assumed that, of all women infected, the same fraction would develop PID in the absence of an intervention. We examined two sets of assumptions used to calculate the sample size in a published RCT that investigated the effect of chlamydia screening on PID incidence. We also investigated the influence of the natural history parameters of chlamydia on the required sample size. RESULTS The assumed event rates and effect sizes used for the sample size calculation implicitly determined the temporal relationship between chlamydia infection and PID in the model. Even small changes in the assumed PID incidence and relative risk (RR) led to considerable differences in the hypothesised mechanism of PID development. The RR and the sample size needed per group also depend on the natural history parameters of chlamydia. CONCLUSIONS Mathematical modelling helps to understand the temporal relationship between an infection and its sequelae and can show how uncertainties about natural history parameters affect sample size calculations when planning a RCT.

Effect of low count sums on quantitative environmental reconstructions: an example using subfossil chironomids

The concentrations of chironomid remains in lake sediments are very variable and, therefore, chironomid stratigraphies often include samples with a low number of counts. Thus, the effect of low count sums on reconstructed temperatures is an important issue when applying chironomid‐temperature inference models. Using an existing data set, we simulated low count sums by randomly picking subsets of head capsules from surface‐sediment samples with a high number of specimens. Subsequently, a chironomid‐temperature inference model was used to assess how the inferred temperatures are affected by low counts. The simulations indicate that the variability of inferred temperatures increases progressively with decreasing count sums. At counts below 50 specimens, a further reduction in count sum can cause a disproportionate increase in the variation of inferred temperatures, whereas at higher count sums the inferences are more stable. Furthermore, low count samples may consistently infer too low or too high temperatures and, therefore, produce a systematic error in a reconstruction. Smoothing reconstructed temperatures downcore is proposed as a possible way to compensate for the high variability due to low count sums. By combining adjacent samples in a stratigraphy, to produce samples of a more reliable size, it is possible to assess if low counts cause a systematic error in inferred temperatures.

A Hartree-Fock Example Using Helium

The Hartree-Fock method is applied to Helium's electrons to show explicitly how the coupled equations reflect the interactions between electrons.

Assessing Treatment Integrity: A Case Example

This paper presents an example of assessing treatment integrity as part of an experimental study of home-based, intensive family preservation services (IFPS). Participants were 103 IFPS workers and 24 state public child welfare agency workers (FC). The structured, self-report questionnaire included questions about specific components of the services, as well as the characteristics of the family and the workers themselves. Findings suggest that IFPS workers delivered services according to the treatment model guidelines. The procedure yielded a good estimate of whether the structural components of treatment were delivered according to the model as delineated in the treatment manual. The paper discusses the advantages and disadvantages of this approach to assessing treatment integrity.

Converting Land from Poplar Tree Bioenergy Planting to Cropland: An Example

Many landowners ask about the process and costs for returning land to crop production after trees are cut for biomass. A field on the Squaw Creek bottom, Story County, Iowa was planted to hybrid poplar trees in spring 2000. The trees were planted in rows with a 10-ft spacing. The trees were cut in spring 2010. The resulting field was four acres, and this is the account of the first corn crop in 2011 on the area.

Territorial assemblages and Governance : The example of the Taonaba project [Town of Abymes, Guadeloupe]

This article reports on an action research to support the urban community of Cap Excellence in Guadaloupe in its local sustainable development project. After summarizing the terms of the debate around sustainable development, and presenting the region, the search will be put back into the context of a more general approach of territorial* intelligence (TI). The limits of a local Agenda 21 in the form of a 'programmed action plan' is the chance to enhance the concept of TI with that of territorial assemblage. Our study area is the natural reserve of the Grand Cul-de-Sac Marin of Guadeloupe, the second largest biosphere reserve designated by UNESCO in the archipelago of the Petites Antilles, more specifically the implementation of the Taonaba project, whose goal is to launch an ecotourism visitors' centre, operational at the end of 2012. Based on the analysis of a large amount of data, the article describes an evaluation tool for territorial assemblages for participative territorial governance. Our results were presented to local government officials in the Urban Sustainable Development Forum, which our group organised from 2 to 4 April 2012, in the district of Abymes/Pointe-à-Pitre

Territorial assemblages and Governance : The example of the Taonaba project [Town of Abymes, Guadeloupe]

This article reports on an action research to support the urban community of Cap Excellence in Guadaloupe in its local sustainable development project. After summarizing the terms of the debate around sustainable development, and presenting the region, the search will be put back into the context of a more general approach of territorial* intelligence (TI). The limits of a local Agenda 21 in the form of a 'programmed action plan' is the chance to enhance the concept of TI with that of territorial assemblage. Our study area is the natural reserve of the Grand Cul-de-Sac Marin of Guadeloupe, the second largest biosphere reserve designated by UNESCO in the archipelago of the Petites Antilles, more specifically the implementation of the Taonaba project, whose goal is to launch an ecotourism visitors' centre, operational at the end of 2012. Based on the analysis of a large amount of data, the article describes an evaluation tool for territorial assemblages for participative territorial governance. Our results were presented to local government officials in the Urban Sustainable Development Forum, which our group organised from 2 to 4 April 2012, in the district of Abymes/Pointe-à-Pitre

Territorial assemblages and Governance : The example of the Taonaba project [Town of Abymes, Guadeloupe]

This article reports on an action research to support the urban community of Cap Excellence in Guadaloupe in its local sustainable development project. After summarizing the terms of the debate around sustainable development, and presenting the region, the search will be put back into the context of a more general approach of territorial* intelligence (TI). The limits of a local Agenda 21 in the form of a 'programmed action plan' is the chance to enhance the concept of TI with that of territorial assemblage. Our study area is the natural reserve of the Grand Cul-de-Sac Marin of Guadeloupe, the second largest biosphere reserve designated by UNESCO in the archipelago of the Petites Antilles, more specifically the implementation of the Taonaba project, whose goal is to launch an ecotourism visitors' centre, operational at the end of 2012. Based on the analysis of a large amount of data, the article describes an evaluation tool for territorial assemblages for participative territorial governance. Our results were presented to local government officials in the Urban Sustainable Development Forum, which our group organised from 2 to 4 April 2012, in the district of Abymes/Pointe-à-Pitre

Does Encapsulation Protect Embryos from the Effects of Ocean Acidification? The Example of Crepidula fornicata

Early life history stages of marine organisms are generally thought to be more sensitive to environmental stress than adults. Although most marine invertebrates are broadcast spawners, some species are brooders and/or protect their embryos in egg or capsules. Brooding and encapsulation strategies are typically assumed to confer greater safety and protection to embryos, although little is known about the physico-chemical conditions within egg capsules. In the context of ocean acidification, the protective role of encapsulation remains to be investigated. To address this issue, we conducted experiments on the gastropod Crepidula fornicata. This species broods its embryos within capsules located under the female and veliger larvae are released directly into the water column. C. fornicata adults were reared at the current level of CO2 partial pressure (pCO2) (390 µatm) and at elevated levels (750 and 1400 µatm) before and after fertilization and until larval release, such that larval development occurred entirely at a given pCO2. The pCO2 effects on shell morphology, the frequency of abnormalities and mineralization level were investigated on released larvae. Shell length decreased by 6% and shell surface area by 11% at elevated pCO2 (1400 µatm). The percentage of abnormalities was 1.5- to 4-fold higher at 750 µatm and 1400 µatm pCO2, respectively, than at 390 µatm. The intensity of birefringence, used as a proxy for the mineralization level of the larval shell, also decreased with increasing pCO2. These negative results are likely explained by increased intracapsular acidosis due to elevated pCO2 in extracapsular seawater. The encapsulation of C. fornicata embryos did not protect them against the deleterious effects of a predicted pCO2 increase. Nevertheless, C. fornicata larvae seemed less affected than other mollusk species. Further studies are needed to identify the critical points of the life cycle in this species in light of future ocean acidification.