Likelihood inference for exponential-trawl processes

Integer-valued trawl processes are a class of serially correlated, stationary and infinitely divisible processes that Ole E. Barndorff-Nielsen has been working on in recent years. In this Chapter, we provide the first analysis of likelihood inference for trawl processes by focusing on the so-called exponential-trawl process, which is also a continuous time hidden Markov process with countable state space. The core ideas include prediction decomposition, filtering and smoothing, complete-data analysis and EM algorithm. These can be easily scaled up to adapt to more general trawl processes but with increasing computation efforts.Comment: 29 pages, 6 figures, forthcoming in: "A Fascinating Journey through Probability, Statistics and Applications: In Honour of Ole E. Barndorff-Nielsen's 80th Birthday", Springer, New Yor

Removal of Ni (II) and Pb (II) ions from aqueous solutions by grapefruit (Citrus paradisi) Mesocarp Biomass

The surface characteristics of Citrus paradisi (grapefruit mesocarp biomass) on the biosorption of Ni (II) and Pb (II) ions from aqueous solution were studied adopting a batch reactor technique. The dried  grapefruit mesocarp biomass was characterized using phytochemical screening and Fourier Transform  Infra – Red (FTIR) Spectroscopy. The results of the characterization revealed the presence of alkaloids, tannins, saponins, cyanogenic glycosides. Furthermore, the FTIR spectrum pattern of the biomass  showed broad and sharp absorption peaks indicating the existence of functional groups like – OH, C=O, C-H, C-O, N-H, etc. The biosorption process was found to be pH, time and concentration dependent. The rate of biosorption was higher in Ni (II) ion than Pb (II) ion. The result of the  equilibrium modeling showed that the biosorption process fitted well with the Freundlich isotherm equation indicating a muiltilayer biosorption. The mechanism of the biosorption process followed pseudo – second – order kinetic model equation with correlation coefficient (R2) of 0.999 for Ni (II) ion and 0.991 for Pb (II) ion  respectively. Thermodynamic parameters determined showed that the biosorption of Ni (II) and Pb (II) ions on the surface of the biomass was an exothermic and spontaneous process. The rate of biosorption was found to decrease with increasing temperature. The results showed that the dried grapefruit mesocarp biomass was efficient and effective in the biosorption of Ni (II) and Pb (II) ions and is recommended to be applied in wastewaters.Keywords: Citrus paradisi, biosorption, metal ions, characterization, mechanism

Economic Potential of Taungya Farming System in Edo State, Nigeria

The study examined the economic potential of taungya system in Edo state, using of data obtained from both primary and secondary sources with the aid of well structured questionnaires administered to 230 respondents in eight the Local Government Areas practicing taungya farming in government reserved forests. The research was based on sampling intensities of 30, 20 and 5% for farmers’ population of below 100, between 100 and 200 and over 200 respectively, to elicit information on socioeconomic issues. Data were analyzed with descriptive statistic of frequency and percentages and inferential statistic using “t” test and ANOVA. The results showed that 43.3% of the respondents affirmed that it was easy to obtain fuelwood, while 41.1% of them believed that was very easy to obtain fuelwood in the taungya farm system. Results showed that there was significant difference (P<0.05) among the income generated from benefits like food, fuelwood, fruits/vegetable/roots, bushmeat, medicinal plants. The results also revealed that the revenues government generated from allocation of taungya plots differed significantly among revenues types and (P<.05) various periods considered. Retention fees and April 2009 to date dominated the types of revenues and period respectively. It is expedient to enhance the economic potential of taungya so as to convert all the possible potentials to reality. This is done by following values premises for the adoption of taungya system in the real sense of it in most of the forest estates in the state.Keywords: Taungya, economic potential, income, revenues, concessionJournal of Agriculture and Social Research (JASR) Vol. 11, No. 1, 201

Vanishing largest Lyapunov exponent and Tsallis entropy

We present a geometric argument that explains why some systems having vanishing largest Lyapunov exponent have underlying dynamics aspects of which can be effectively described by the Tsallis entropy. We rely on a comparison of the generalised additivity of the Tsallis entropy versus the ordinary additivity of the BGS entropy. We translate this comparison in metric terms by using an effective hyperbolic metric on the configuration/phase space for the Tsallis entropy versus the Euclidean one in the case of the BGS entropy. Solving the Jacobi equation for such hyperbolic metrics effectively sets the largest Lyapunov exponent computed with respect to the corresponding Euclidean metric to zero. This conclusion is in agreement with all currently known results about systems that have a simple asymptotic behaviour and are described by the Tsallis entropy.Comment: 15 pages, No figures. LaTex2e. Some overlap with arXiv:1104.4869 Additional references and clarifications in this version. To be published in QScience Connec

Involuntary civil commitment for substance use disorders in puerto rico: Neglected rights violations and implications for legal reform

Laws facilitating the involuntary civil commitment (ICC) of people with substance use disorders vary considerably internationally and across the United States. Puerto Rico, a colonial territory of the United States since 1898, currently harbors the most punitive ICC legislation in the country. It is the only place in the United States where self-sufficient adults who pose no grave danger to themselves or others can be involuntarily committed to restrictive residential facilities for over a year at a time without ever being assessed by a health care professional. The involuntary commitment of otherwise-able citizens—many of whom have never been diagnosed with a substance use disorder—continues to be ignored nationally and internationally. In this paper, we specify how Puerto Rican ICC law and procedures systematically violate rights and liberties that are supposed to be guaranteed by Puerto Rico’s Mental Health Act, the US Federal Supreme Court, and the Universal Declaration of Human Rights. To ensure that Puerto Rico’s ICC procedures conform to prevailing local, national, and international standards, we propose a series of legislative reforms. Finally, we highlight the importance of addressing the preponderance of poorly constructed ICC laws both within the United States and internationally

Complementary approaches to understanding the plant circadian clock

This is the final version of the article. Available from the Open Publishing Association via the DOI in this record.Proceedings - Third Workshop 'From Biology To Concurrency and back', Paphos, Cyprus, 27 March 2010Circadian clocks are oscillatory genetic networks that help organisms adapt to the 24-hour day/night cycle. The clock of the green alga Ostreococcus tauri is the simplest plant clock discovered so far. Its many advantages as an experimental system facilitate the testing of computational predictions. We present a model of the Ostreococcus clock in the stochastic process algebra Bio-PEPA and exploit its mapping to different analysis techniques, such as ordinary differential equations, stochastic simulation algorithms and model-checking. The small number of molecules reported for this system tests the limits of the continuous approximation underlying differential equations. We investigate the difference between continuous-deterministic and discrete-stochastic approaches. Stochastic simulation and model-checking allow us to formulate new hypotheses on the system behaviour, such as the presence of self-sustained oscillations in single cells under constant light conditions. We investigate how to model the timing of dawn and dusk in the context of model-checking, which we use to compute how the probability distributions of key biochemical species change over time. These show that the relative variation in expression level is smallest at the time of peak expression, making peak time an optimal experimental phase marker. Building on these analyses, we use approaches from evolutionary systems biology to investigate how changes in the rate of mRNA degradation impacts the phase of a key protein likely to affect fitness. We explore how robust this circadian clock is towards such potential mutational changes in its underlying biochemistry. Our work shows that multiple approaches lead to a more complete understanding of the clock.The authors thank Gerben van Ooijen for TopCount data and Jane Hillston and Andrew Millar for their helpful comments. The Centre for Systems Biology at Edinburgh is a Centre for Integrative Systems Biology (CISB) funded by BBSRC and EPSRC, ref. BB/D019621/1. CT is supported by The International Human Frontier Science Program Organization

The theory of international business: the role of economic models

This paper reviews the scope for economic modelling in international business studies. It argues for multi-level theory based on classic internalisation theory. It present a systems approach that encompasses both firm-level and industry-level analysis

Cerebral Glycogen Distribution and Aging

In the brain, glycogen metabolism has been implied in synaptic plasticity and learning, yet the distribution of this molecule has not been fully described. We investigated cerebral glycogen of the mouse by immunohistochemistry (IHC) using two monoclonal antibodies that have different affinities depending on the glycogen size. The use of focused microwave irradiation yielded well‐defined glycogen immunoreactive signals compared with the conventional periodic acid‐Schiff method. The IHC signals displayed a punctate distribution localized predominantly in astrocytic processes. Glycogen immunoreactivity (IR) was high in the hippocampus, striatum, cortex, and cerebellar molecular layer, whereas it was low in the white matter and most of the subcortical structures. Additionally, glycogen distribution in the hippocampal CA3‐CA1 and striatum had a ‘patchy’ appearance with glycogen‐rich and glycogen‐poor astrocytes appearing in alternation. The glycogen patches were more evident with large‐molecule glycogen in young adult mice but they were hardly observable in aged mice (1–2 years old). Our results reveal brain region‐dependent glycogen accumulation and possibly metabolic heterogeneity of astrocytes

Seasonal variation in tissue-borne heavy metal(loid)s in herbaceous plants growing in contaminated soils developed from industrial wastes of Industrial Revolution age

A 1-year monitoring program was performed to examine the seasonal variation in shoot-borne heavy metal(loid)s in a dominant herbaceous plant species (creeping bentgrass) growing in contaminated soils developed from industrial wastes of Industrial Revolution age in Greater Manchester, UK. Heavy metal(loid)s in soil and plant tissues were quantified by inductively coupled plasma optical emission spectrometry (ICP-OES) after microwave-assisted acid digestion. The results show that different heavy metal(loid)s in the shoot tissue had different seasonal variation patterns. Seasonal shoot cutting-regrowth did not markedly affect the accumulation of various heavy metal(loid)s in the shoots. The concentration of shoot-borne heavy metal(loid)s was below the maximum tolerable level set for cattle except for Cd during spring-summer. The seasonal variation pattern for removal rate of Cd, Cr, Cu, Pb and Zn was strongly controlled by seasonal variation in biomass yield. The heavy metal(loid) removal from the soils via seasonal shoot harvest was 0.11, 0.56, 0.57, 3.56, 60.4, 0.34, 0.27 and 12.3 mg/m2 for As, Cd, Cr, Cu, Mn, Ni, Pb and Zn, respectively. It is estimated that during the 1-year monitoring period, only 0.0002, 0.4014, 0.0142, 0.0423, 0.1627, 0.0154, 0.0008 and 0.1840% of the total metal(loid)s were removed from the soil by the plant shoots for As, Cd, Cr, Cu, Mn, Ni, Pb and Zn, respectively. Phytoextraction literally had negligible effects on removing the investigated heavy metal(loid)s from the contaminated soils except for Cd, Mn and Zn. The average bioaccumulation factor for the investigated heavy metal(loid)s was in the following decreasing order: Zn > Mn > Cu > Cr > Ni > Cd > Pb > As. The translocation factor for Cd was over 10 under either non-regrowth or cutting-regrowth conditions although the bioaccumulation factor was smaller than 0.5. The research findings obtained from this study have implications for risk assessment and management of the industrial waste-turned contaminated soils