Tropical shelterwood system of forest regeneration its development and application in the Benin Division of Southern Nigeria and a consideration of factors affecting its success

It is the purpose of this paper to give a description of the development of a system of natural regeneration for the Benin forests, to measure the success of the work, and to set out some of the factors which appear to limit or to assist the regeneration. Between the latitudes 6 and 7 degrees north and the longitudes 5 and 6 degrees east in Western Provinces, Kigeria,is situated Benin Division, the most southern and western of the four political Divisions which together form Benin Province. The area of Benin Division is approximately 4,000 square miles, and in 1931 (the latest census figures available) the population was taken to be 111,000, although there is no doubt that during the last two decades this latter figure has greatly increased due to a rising birth -rate and an influx of labour, mainly from the south and east, to the prosperous rubber estates and expanding timber industry. The provincial and divisional capital, Benin City, lies in the centre of the Division. With a population of over 20,000 it is the hub from which radiate the several roads which serve the many small and few large villages of the area and which link the capital with neighbouring Provinces. GEOLOGY: Crystalline rocks (the "undifferentiated basement complex" of gneisses and granites) occur in the extreme north-west of the Division, but the remainder is entirely sedimentary, being part of the extensive Benin Sand Series. In parts this formation consists of a homogeneous layer of quartz sand several hundred feet thick, but the Benin Sands may be part of the Lignite Series, in which unevenly distributed strata of sandstone, shales and clays occur in the red sands. RAINFALL AND DRAINAGE: The average rainfall of the whole Division is probably about 75 inches per annum, distributed in the typical two-peak fashion of the coast of West Africa. The rainfall in the south averages 110 inches per annum (probably higher in the extreme southwest) but that in the extreme north may be as low as 60 inches. The figures for Benin City show that the months of November, Decembers January and February have precipitation below 3 inches per month, but the relative humidity (especially in the forest) remains fairly high throughout the year, and the effect of the dry Harmattan wind from the north is weak and is obvious on only very few, isolated days. The table (t ore p. 3 shows average rainfall, temperature and relative humidity figures for Benin City which is not itself in the forest. Within the forest the mean relative humidity, particularly at 3 p.m., is higher and probably without such large fluctuations between months. The area of the Benin Sands is characterised by a scarcity of streams and the rain water appears to drain to considerable depth, the rivers flowing in deep trenches cut below the general level of the almost flat plain. Except on land which has been completely cleared of vegetation there is little run-off, and the streams, fed by underground drainage, generally hold deep and very clear water. Chukwuogo and other writers have stressed the severe water shortage which exists in the country districts, in the dry season, away from the limited number of streaa. FARMING: The local food farming technique involves the practice of a bush fallow system; the number of years for which a farm is cropped is small, usually two, or possibly three years if the land proves to be of high qw l ity, and this is an index of the rapidity at which the Benin Sands lose their fertility after the removal of the forest vegetation. The farmer cuts, heaps and burns almost every tree on the new farm, and this practice of leaving no high shade has important ecological and economic repercussions. There is a sharp contrast with the practice in other parts of West Africa where the largest trees remain as a high shade, an important reservoir of timber, a source of seed and a skeleton of forest structure. There are practically no cattle in the Division owing to the susceptibility of all but a few strains to trypanosomiasis. The most common domestic animal is the goat, which is here a village or compound animal, living by scavenging and seldom, if, ever, found either it forest or farm. An important plantation crop of the Division is rubber and considerable areas have been planted with Heavea brasil,iensis. During the 1939 - 45 war the plantations prospered, and were largely extended Owing to the inflated price of rubber following the Japanese occupation of Malaya, but the present prices are subject to large fluctuations. TIMBER. By far the most important industry, apart from food farming for local use, is timber working. On this trade, whether for the export market or the Nigerian market, the prosperity of Benin largely depends. A result of the rising standard of living of many Nigerian people, and the growing needs of industry in West Africa and abroad, is that the demand for Nigerian timber has increased. At the same time the area of non reserved forest (forest land not included in Forest Reserves) has been greatly reduced in the last fifteen years owing to the destructive work of farmers and the planting of permanent cash crops. The supply of timber outside the gazetted Reserves dwindled rapidly, particularly because of the clear-felling technique of the farmers, and the Forest Department was faced some years ago with the need to allow the exploitation of Forest Reserves to begin; such exploitation had to be accompanied by regeneration, either artificial or natural. Artificial regeneration, while important in certain limited areas and for special purposes, could not be attempted on the scale necessary to ensure the future of the forests and thus natural regeneration had to be attempted on an enormous scale. The intention in this paper is to describe briefly the technique of natural regeneration adopted and to examine in some detail the success obtained in different forest associations in a single compartment with the object of assessing the suitability of the technique for the maintenance of the forest

Incorporating patient preferences in the management of multiple long-term conditions: is this a role for clinical practice guidelines?

Background: Clinical practice guidelines provide an evidence-based approach to managing single chronic conditions, but their applicability to multiple conditions has been actively debated. Incorporating patient-preference recommendations and involving consumers in guideline development may enhance their applicability, but further understanding is needed. Objectives: To assess guidelines that include recommendations for comorbid conditions to determine the extent to which they incorporate patient-preference recommendations; use consumer-engagement processes during development, and, if so, whether these processes produce more patient-preference recommendations; and meet standard quality criteria, particularly in relation to stakeholder involvement. Design: A review of Australian guidelines published from 2006 to 2014 that incorporated recommendations for managing comorbid conditions in primary care. Document analysis of guidelines examined the presence of patient-preference recommendations and the consumer-engagement processes used. The Appraisal of Guidelines for Research and Evaluation instrument was used to assess guideline quality. Results: Thirteen guidelines were reviewed. Twelve included at least one core patient-preference recommendation. Ten used consumer-engagement processes, including participation in development groups (seven guidelines) and reviewing drafts (ten guidelines). More extensive consumer engagement was generally linked to greater incorporation of patient-preference recommendations. Overall quality of guidelines was mixed, particularly in relation to stakeholder involvement. Conclusions: Guidelines do incorporate some patient-preference recommendations, but more explicit acknowledgement is required. Consumer-engagement processes used during guideline development have the potential to assist in identifying patient preferences, but further research is needed. Clarification of the consumer role and investment in consumer training may strengthen these processes.Journal of Comorbidity 2015;5(1):122–13

Dark-Ages Reionisation & Galaxy Formation Simulation XVI: The Thermal Memory of Reionisation

Intergalactic medium temperature is a powerful probe of the epoch of reionisation, as information is retained long after reionisation itself. However, mean temperatures are highly degenerate with the timing of reionisation, with the amount heat injected during the epoch, and with the subsequent cooling rates. We post-process a suite of semi-analytic galaxy formation models to characterise how different thermal statistics of the intergalactic medium can be used to constrain reionisation. Temperature is highly correlated with redshift of reionisation for a period of time after the gas is heated. However as the gas cools, thermal memory of reionisation is lost, and a power-law temperature-density relation is formed, $T = T_0(1+\delta)^{1-\gamma}$ with $\gamma \approx 1.5$. Constraining our model against observations of electron optical depth and temperature at mean density, we find that reionisation likely finished at $z_{\rm{reion}} = 6.8 ^{+ 0.5} _{-0.8}$ with a soft spectral slope of $\alpha = 2.8 ^{+ 1.2} _{-1.0}$. By restricting spectral slope to the range $[0.5,2.5]$ motivated by population II synthesis models, reionisation timing is further constrained to $z_{\rm{reion}} = 6.9 ^{+ 0.4} _{-0.5}$. We find that, in the future, the degeneracies between reionisation timing and background spectrum can be broken using the scatter in temperatures and integrated thermal history.Comment: 17 pages, 17 figures, Accepted for publication in MNRA

Genotoxic effect induced by hydrogen peroxide in human hepatoma cells using comet assay

Background: Hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) is a common reactive oxygen intermediate generated by various forms of oxidative stress. Aim: The aim of this study was to investigate the DNA damage capacity of H<sub>2</sub>O<sub>2</sub> in HepG2 cells. Methods: Cells were treated with H<sub>2</sub>O<sub>2</sub> at concentrations of 25 mM or 50 mM for 5 min, 30 min, 40 min, 1 h, or 24 h in parallel. The extent of DNA damage was assessed by the comet assay. Results: Compared to the control, DNA damage by 25 and 50 mM H<sub>2</sub>O<sub>2</sub> increased significantly with increasing incubation time up to 1 h, but it was not increased at 24 h. Conclusions: Our findings confirm that H<sub>2</sub>O<sub>2</sub> is a typical DNA damage-inducing agent and thus is a good model system to study the effects of oxidative stress. DNA damage in HepG2 cells increased significantly with H<sub>2</sub>O<sub>2</sub> concentration and time of incubation but later decreased likely due to DNA repair mechanisms and antioxidant enzymes.Keywords: DNA damage; hydrogen peroxide; HepG2 cells; comet assa

Are care plans suitable for the management of multiple conditions?

Care plans have been part of the primary care landscape in Australia for almost two decades. With an increasing number of patients presenting with multiple chronic conditions, it is timely to consider whether care plans meet the needs of patients and clinicians.To review and benchmark existing care plan templates that include recommendations for comorbid conditions, against four key criteria: (i) patient preferences, (ii) setting priorities, (iii) identifying conflicts and synergies between conditions, and (iv) setting dates for reviewing the care plan.Document analysis of Australian care plan templates published from 2006 to 2014 that incorporated recommendations for managing comorbid conditions in primary care.Sixteen templates were reviewed. All of the care plan templates addressed patient preference, but this was not done comprehensively. Only three templates included setting priorities. None assisted in identifying conflicts and synergies between conditions. Fifteen templates included setting a date for reviewing the care plan.Care plans are a well-used tool in primary care practice, but their current format perpetuates a single-disease approach to care, which works contrary to their intended purpose. Restructuring care plans to incorporate shared decision-making and attention to patient preferences may assist in shifting the focus back to the patient and their care needs

Imaging Active Infection in vivo Using D-Amino Acid Derived PET Radiotracers.

Occult bacterial infections represent a worldwide health problem. Differentiating active bacterial infection from sterile inflammation can be difficult using current imaging tools. Present clinically viable methodologies either detect morphologic changes (CT/ MR), recruitment of immune cells (111In-WBC SPECT), or enhanced glycolytic flux seen in inflammatory cells (18F-FDG PET). However, these strategies are often inadequate to detect bacterial infection and are not specific for living bacteria. Recent approaches have taken advantage of key metabolic differences between prokaryotic and eukaryotic organisms, allowing easier distinction between bacteria and their host. In this report, we exploited one key difference, bacterial cell wall biosynthesis, to detect living bacteria using a positron-labeled D-amino acid. After screening several 14C D-amino acids for their incorporation into E. coli in culture, we identified D-methionine as a probe with outstanding radiopharmaceutical potential. Based on an analogous procedure to that used for L-[methyl-11C]methionine ([11C] L-Met), we developed an enhanced asymmetric synthesis of D-[methyl-11C]methionine ([11C] D-Met), and showed that it can rapidly and selectively differentiate both E. coli and S. aureus infections from sterile inflammation in vivo. We believe that the ease of [11C] D-Met radiosynthesis, coupled with its rapid and specific in vivo bacterial accumulation, make it an attractive radiotracer for infection imaging in clinical practice

The institutional shaping of management: in the tracks of English individualism

Globalisation raises important questions about the shaping of economic action by cultural factors. This article explores the formation of what is seen by some as a prime influence on the formation of British management: individualism. Drawing on a range of historical sources, it argues for a comparative approach. In this case, the primary comparison drawn is between England and Scotland. The contention is that there is a systemic approach to authority in Scotland that can be contrasted to a personal approach in England. An examination of the careers of a number of Scottish pioneers of management suggests the roots of this systemic approach in practices of church governance. Ultimately this systemic approach was to take a secondary role to the personal approach engendered by institutions like the universities of Oxford and Cambridge, but it found more success in the different institutional context of the USA. The complexities of dealing with historical evidence are stressed, as is the value of taking a comparative approach. In this case this indicates a need to take religious practice as seriously as religious belief as a source of transferable practice. The article suggests that management should not be seen as a simple response to economic imperatives, but as shaped by the social and cultural context from which it emerges

Imaging glutathione depletion in the rat brain using ascorbate-derived hyperpolarized MR and PET probes.

Oxidative stress is a critical feature of several common neurologic disorders. The brain is well adapted to neutralize oxidative injury by maintaining a high steady-state concentration of small-molecule intracellular antioxidants including glutathione in astrocytes and ascorbic acid in neurons. Ascorbate-derived imaging probes for hyperpolarized 13C magnetic resonance spectroscopy and positron emission tomography have been used to study redox changes (antioxidant depletion and reactive oxygen species accumulation) in vivo. In this study, we applied these imaging probes to the normal rat brain and a rat model of glutathione depletion. We first studied hyperpolarized [1-13C]dehydroascorbate in the normal rat brain, demonstrating its robust conversion to [1-13C]vitamin C, consistent with rapid transport of the oxidized form across the blood-brain barrier. We next showed that the kinetic rate of this conversion decreased by nearly 50% after glutathione depletion by diethyl maleate treatment. Finally, we showed that dehydroascorbate labeled for positron emission tomography, namely [1-11C]dehydroascorbate, showed no change in brain signal accumulation after diethyl maleate treatment. These results suggest that hyperpolarized [1-13C]dehydroascorbate may be used to non-invasively detect oxidative stress in common disorders of the brain

Magnetic interactions in the S = 1/2 square-lattice antiferromagnets Ba2CuTeO6 and Ba2CuWO6: parent phases of a possible spin liquid

The isostructural double perovskites Ba2CuTeO6 and Ba2CuWO6 are shown by theory and experiment to be frustrated square-lattice antiferromagnets with opposing dominant magnetic interactions. This is driven by differences in orbital hybridisation of Te6+ and W6+. A spin-liquid-like ground state is predicted for Ba2Cu(Te1-xWx)O6 solid solution similar to recent observations in Sr2Cu(Te1-xWx)O6