ALPprolog --- A New Logic Programming Method for Dynamic Domains

Logic programming is a powerful paradigm for programming autonomous agents in dynamic domains, as witnessed by languages such as Golog and Flux. In this work we present ALPprolog, an expressive, yet efficient, logic programming language for the online control of agents that have to reason about incomplete information and sensing actions.Comment: 16 page

Under consideration for publication in Theory and Practice of Logic Programming ALPprolog -A New Logic Programming Method for Dynamic Domains

Abstract Logic programming is a powerful paradigm for programming autonomous agents in dynamic domains, as witnessed by languages such as Golog and Flux. In this work we present ALPprolog, an expressive, yet efficient, logic programming language for the online control of agents that have to reason about incomplete information and sensing actions

Adapting a practical EPR dosimetry protocol to measure output factors in small fields with alanine.

PURPOSE Modern radiotherapy techniques often deliver small radiation fields. In this work, a practical Electron Paramagnetic Resonance (EPR) dosimetry protocol is adapted and applied to measure output factors (OF) in small fields of a 6 MV radiotherapy system. Correction factors and uncertainties are presented and OFs are compared to the values obtained by following TRS-483 using an ionization chamber (IC). METHODS Irradiations were performed at 10 cm depth inside a water phantom positioned at 90 cm source to surface distance with a 6 MV flattening filter free photon beam of a Halcyon radiotherapy system. OFs for different nominal field sizes (1 × 1, 2 × 2, 3 × 3, 4 × 4, normalized to 10 × 10 cm2 ) were determined with a PinPoint 3D (PTW 31022) IC following TRS-483 as well as with alanine pellets with a diameter of 4 mm and a height of 2.4 mm. EPR readout was performed with a benchtop X-band spectrometer. Correction factors due to volume averaging and due to positional uncertainties were derived from 2D film measurements. RESULTS OFs obtained from both dosimeter types agreed within 0.7% after applying corrections for the volume averaging effect. For the used alanine pellets, volume averaging correction factors of 1.030(2) for the 1 × 1 cm2 field and <1.002 for the larger field sizes were determined. The correction factor for positional uncertainties of 1 mm was in the order of 1.018 for the 1 × 1 cm2 field. Combined relative standard uncertainties uc for the OFs resulting from alanine measurements were estimated to be below 1.5% for all field sizes. For IC measurements, uc was estimated to be below 1.0%. CONCLUSIONS A practical EPR dosimetry protocol is adaptable for precisely measuring OFs in small fields down to 1 × 1 cm2 . It is recommended to consider the effect of positional uncertainties for field sizes <2 × 2 cm2

Heat Transfer Characteristics of a Pipeline for CO2 Transport with Water as Surrounding Substance

AbstractThe heat transfer characteristics of pipelines for transport of CO2 is crucial for the events following a depressurization or a crack formation, involving rapid cooling. In this work, we present and analyze recent experiments from an experimental facility tailored to investigate these phenomena. With stagnant water as the surrounding substance, we quantify the contribution to the heat transfer from the surroundings, the insulation and the CO2 boiling inside the pipeline, for a large set of operating conditions. We discuss whether empirical expressions in the literature can describe the outer heat transfer coefficient and analyze the experimental results in detail using computational fluid dynamical simulations. The work gives insight into and quantifies the heat transfer characteristics of a CO2-pipeline. In particular, the outer heat transfer coefficient was between 80 and 210W/m2K, the thermal conductivity of the insulation was well described by a linear temperature relation and the mean value of the overall heat transfer coefficient was 44.7W/m2K. The work lays the foundation for future work on this subject, which will involve other surrounding substances such as clay and gravel as well as the forming of ice

Promoting indigenous vegetables in urban agriculture & livelihoods : policy lessons from Sub-Saharan Africa

[From Introduction] Globally, the growth of urbanised areas continues at an exponential rate, and most spectacularly in the developing world. The global urban population will increase from 2.9 billion in 2000 to 5.0 billion by 2030. The mean rate of urban growth in non-OECD countries between 2000 and 2005 was just under 3% per annum, compared to 0.5 % for rural regions of the same countries (UN-Habitat 2006). Although the proportion of Africans currently living in urban areas is the lowest in the world (+ 40%), because of this low base it is not unsurprising that the rates of urbanisation are among the highest at approximately 4.3% per annum. Projections vary, but sometime in the mid- 2020s over 50% of Africa's population will be living in urban areas, as compared to just 15% in 1950 and 34% in 1994. As urbanisation takes place another important trend is revealed, namely the locus of poverty in Africa is slowly shifting from rural to urban areas. For example, it is estimated that more than 56% of the world's absolute or chronic poor will be concentrated in urban areas (WRI 1996). Since as much as 60-80% of the income of the urban poor is spent on the purchase of food (Maxwell et al. 2000), the issue of food supply, both its quantity and quality, is increasingly a central issue in poverty reduction debates and strategies. In rural areas, a common strategy to alleviate poverty is to call for measures to boost small-holder food production. Surprisingly, this is less common in urban poverty alleviation programmes, despite the widespread promise of urban and household agriculture in contributing to improved food security

Putting ABox Updates into Action

When trying to apply recently developed approaches for updating Description Logic ABoxes in the context of an action programming language, one encounters two problems. First, updates generate so-called Boolean ABoxes, which cannot be handled by traditional Description Logic reasoners. Second, iterated update operations result in very large Boolean ABoxes, which, however, contain a huge amount of redundant information. In this paper, we address both issues from a practical point of view

Policy brief, number 11, 2014

[From Introduction] Urbanisation in sub-Saharan Africa: changing the locus of poverty. Urbanisation is a global phenomenon that is changing the face of the Earth, as well as how people earn a living and secure their livelihoods. In 2006 the number of urban people in the world surpassed the number of rural people, and this gap will continue to grow. In only 16 years (by 2030) just under two-thirds of the world's people will be urban dwellers. Whilst most of the developed world and large parts of Latin America already have more than threequarters of their populations living in cities and towns, most countries in Asia and sub-Saharan Africa are still catching up. This means that they are experiencing massive migrations from rural to urban areas as rural people wish to swap the insecurities of rural living for the allure of secure employment and better services for health, education, sanitation and transport in towns and cities. Sub-Saharan Africa (SSA) is the most rapidly urbanising region of the globe. According to UN-Habitat, in 1990, only 28 % of the region's inhabitants lived in towns and cities; that increased to approximately 32 % in 2001 and 41 % in 2010. The size of the urban population is likely to surpass the rural one around 2025. Contrary to popular belief, most urban residents in SSA (and globally) live in small towns rather than massive megacities; with just over half living in towns of less than 200,000 people and 78 % living in towns of less than 500,000 residents. Only 14 % of urban dwellers live in cities of more than one million people. Many new urban households maintain strong links to relatives and clans in rural areas, with circular migration patterns emerging as the urban transition takes place over several decades. The implications of this extremely rapid urbanisation in SSA countries for livelihoods and poverty are widely debated. UN-Habitat highlights a relatively unique aspect of urbanisation in SSA as being the accompanying high rate of growth in informal settlements or slums. In other words, not all rural migrants to towns and cities find secure incomes or shelter. Some slum areas have become permanent features where inter-generational poverty is reproduced. Although urban areas are producing an increasing share of national wealth in SSA countries, some argue that slowly the nexus of poverty is shifting towards urban areas. Rates of poverty are high in rural areas of SSA, but migration and internal population growth means that in some countries the number of urban poor almost matches the number of rural poor, and it is likely to grow. The informal economy contributes an average of 40 – 45 % of total urban GDP, which is higher than any other region of the world

Donor Age of Human Platelet Lysate Affects Proliferation and Differentiation of Mesenchymal Stem Cells

The regenerative potential declines upon aging. This might be due to cell-intrinsic changes in stem and progenitor cells or to influences by the microenvironment. Mesenchymal stem cells (MSC) raise high hopes in regenerative medicine. They are usually culture expanded in media with fetal calf serum (FCS) or other serum supplements such as human platelet lysate (HPL). In this study, we have analyzed the impact of HPL-donor age on culture expansion. 31 single donor derived HPLs (25 to 57 years old) were simultaneously compared for culture of MSC. Proliferation of MSC did not reveal a clear association with platelet counts of HPL donors or growth factors concentrations (PDGF-AB, TGF-β1, bFGF, or IGF-1), but it was significantly higher with HPLs from younger donors (<35 years) as compared to older donors (>45 years). Furthermore, HPLs from older donors increased activity of senescence-associated beta-galactosidase (SA-βgal). HPL-donor age did not affect the fibroblastoid colony-forming unit (CFU-f) frequency, immunophenotype or induction of adipogenic differentiation, whereas osteogenic differentiation was significantly lower with HPLs from older donors. Concentrations of various growth factors (PDGF-AB, TGF-β1, bFGF, IGF-1) or hormones (estradiol, parathormone, leptin, 1,25 vitamin D3) were not associated with HPL-donor age or MSC growth. Taken together, our data support the notion that aging is associated with systemic feedback mechanisms acting on stem and progenitor cells, and this is also relevant for serum supplements in cell culture: HPLs derived from younger donors facilitate enhanced expansion and more pronounced osteogenic differentiation

Comparison of the pattern of metastatic spread of squamous cell cancer and adenocarcinoma of the uterine cervix

Retrospective review of medical records and autopsy findings in patients dying of squamous cell cancer or adenocarcinoma of the uterine cervix was undertaken to evaluate for possible differences in biologic behavior between these tumor types. Twenty-one patients with each tumor type were evaluated. Patients with adenocarcinoma were found to have a higher incidence of tumor involvement of the paraaortic lymph nodes (13/21 vs 6/20, P P P P P &lt; 0.05) was also significantly more frequent in patients with adenocarcinoma. These findings suggest that this tumor may behave differently in regard to pattern of metastatic spread or response to therapy. The therapeutic implications of these findings deserve further study.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27919/1/0000342.pd