The importance of bushmeat in the livelihoods of cocoa farmers living in a wildlife depleted farm-forest landscape, SW Ghana

Bushmeat is an important source of cash income and animal protein in rural sub-Saharan Africa. However, hunting levels are largely unsustainable, resulting in the widespread depletion and local extinction of prey species. This is a problem for both the conservation of biodiversity and the sustainable development of rural African communities. This thesis investigates the consequences of wildlife depletion for the livelihood security of Ghanaian cocoa farmers with diversified incomes. The overarching hypothesis that runs through the study is that the importance of bushmeat in livelihoods increases with household vulnerability (i.e. poor households and female-headed households), especially during the agricultural lean season. The study is based primarily on repeated socio-economic questionnaires (N=804), conducted over twelve months among 63 households inWansampo: an agricultural community situated in a forest reserve in SW Ghana. The research found that the amount of bushmeat harvested was low and limited to smallbodied species, suggesting severe depletion of wildlife populations around the study village. Protein insecurity and income poverty were widespread but neither co-varied strongly with household vulnerability. While income poverty was highest during the lean season, total protein consumption/security did not vary across seasons. Hunting was efficiently integrated into agricultural activities, with bushmeat being a minor part of household income and protein consumption. Contrary to expectations, household vulnerability had little effect on the importance of bushmeat in livelihoods. However, during the lean season, the bushmeat harvest increased. Since most bushmeat was consumed by the hunter’s household, the relative dietary importance of bushmeat was highest during the lean season, enabling households to reduce their meat/fish expenditures while maintaining protein consumption levels. Moreover, when income shortages were highest, bushmeat sales increased, preventing some households from falling into income poverty. In summary, despite local wildlife depletion, the importance of bushmeat for both income and protein security increased during the lean season. This suggests that bushmeat is an important safety-net for some households in this community. The thesis concludes by outlining the study’s limitations, before suggesting further research and policy implications

Remote community drinking water supply : mechanisms of uranium retention and adsorption by ultrafiltration, nanofiltration and reverse osmosis

Worldwide, around 884 million people lack access to safe drinking water. To address this, groundwater sources such as boreholes and wells are often installed in remote locations especially in developing countries. However, the natural chemical composition of groundwater may be a source of toxicity to human health. Uranium is naturally present in the environment, and concentrations above the World Health Organisation (WHO) drinking water guideline (15 μg/L) are found in various parts of the world. Uranium has a complex aqueous chemistry and its speciation, which varies according to pH and available ligands, determines its behaviour (e.g. mobility, reactivity or sorption tendency). Nanofiltration and reverse osmosis have proved effective in removing uranium from water, although fundamental removal mechanisms are not well understood. Even the more porous ultrafiltration (UF) has been shown to remove uranium when used in combination with complexation/coagulation methods. To address the water purification needs of remotely located communities with no or unreliable access to energy, a renewable energy powered membrane system was designed using UF as pre-treatment to remove particles, bacteria and viruses and NF/RO to remove ions. The system was trialled in the Australian outback, using natural groundwater high in uranium (>300 μg/L). Results showed that pH had a large effect on the uranium behaviour in the system and, curiously, interaction by sorption or precipitation to the membranes was observed at certain pH values. However, due to the complexity of the water and the combination of UF and NF/RO membranes, the mechanisms of the uranium retention and interaction with the membrane were not clear. Further systematic study was needed to investigate the uranium behaviour with the membranes. Laboratory studies were carried out with one membrane type at a time: UF, NF and RO. It was postulated that pH, organic matter and inorganic ions such as calcium have an important influence on uranium retention and interaction with membranes. Results show that uranium behaviour in the membrane systems was highly pH dependent. During the UF experiments, increased adsorption of uranium occurred in uranium-only solutions at pH 5-7. From the UF experiments with organic matter it could be concluded that organic matter did not increase retention (size exclusion) of uranium, however it did increase the adsorption. Humic acid increased adsorption to 80-95% at pH 3-5, alginic acid at pH 3 while tannic acid caused a nearly 100% adsorption at pH 10-11. Further investigating uranium behaviour with NF and RO membranes, it was found that uranium showed the same increase in affinity to the membrane at pH 5-7, with about 50% being taken up by NF and 30% by RO membranes. The effect of pressure on uranium-membrane interaction was investigated for NF and RO at pH 6 and 8.5. Pressure and consequent concentration polarisation only increased uranium affinity to the NF membrane at pH 8.5 where the uranium species and MWCO of the membrane were similar. There was no or little effect of pressure on the affinity of uranium to the NF membrane at pH 6 or to the RO membrane. At pH 6, STEM-EDX results showed that uranium was distributed through-out the polyamide active layer of the NF membrane while FTIR results confirmed that uranium bound to carboxyl groups in the polyamide. At pH 8.5 however, FTIR results showed that uranium did not form chemical bonds with the membrane, but was rather attracted to the surface through hydrogen bonding and loosely forming a layer on top of the membrane visible in SEM. It was concluded that at least three different characteristics of the uranium species and membranes played a role for the interaction: 1) uranium species valency and membrane charge, 2) uranium species size relative to the membrane pore size, and 3) the reactivity of the uranium species towards the membrane functional groups. The effect of calcium on uranium retention and uranium-membrane interaction in NF and RO was also investigated. Calcium affects uranium speciation by forming a neutral complex with uranium at pH 8-9, causing a decrease in adsorption to the membrane. Calcium also precipitates at pH 10. SEM and TEM images showed that the precipitation of calcium carbonate (CaCO3) as calcite caused co-precipitation of uranium, trapping it on the surface of the membrane. About 48-55% of the calcium precipitated which caused a 26-35% co-precipitation of uranium, compared to <5% adsorption in the absence of calcium at pH 10. Finally the chemical drinking water quality of mainly boreholes and wells across a West African country, Ghana, was investigated (199 samples in total from “improved” sources). In addition, the user water costs were documented and the scope for advanced treatment explored. The WHO guidelines for chemical water quality were exceeded in 38% of the samples. The main contaminants were nitrate (21%), managanese (11%) and fluoride (7%), while heavy metals such as lead, arsenic and uranium were localised to mining areas. It was concluded that when taking the cost of unsuccessful borehole development into account, alternative treatment may be a suitable option where inorganic contamination is high. The findings from this study show the importance of the water quality conditions (pH, organic matter and calcium) on the behaviour of contaminants such as uranium in membrane systems and explain the mechanisms of adsorption and co-precipitation of uranium to the membranes at certain pH values. These are important considerations when selecting appropriate membranes for water treatment and also for the maintenance of membranes. The study also showed that there is need for advanced treatment of drinking water in e.g. Ghana, but highlights the importance of strategies on local and national level to ensure long-term sustainability and integration of any such treatment

What Is the Evidence Base Linking Gender with Access to Forests and Use of Forest Resources for Food Security in Low- and Middle-Income Countries? A Systematic Evidence Map

In nearly all parts of the world, an important part of people's livelihood is derived from natural resources. Gender is considered one of the most important determinants of access and control over forests. It is thought that women and men within households and communities have different opportunities and different roles and responsibilities in relation to forest use. It is probable that when women have equal access to forests, better food security outcomes can be achieved for individuals and households that are dependent on forests for their livelihoods. A systematic evidence map of the evidence base linking gender with access to forests and use of forest resources for food security was undertaken. Ten bibliographic databases and 22 websites of international development and conservation organisations were searched using keywords suggested by stakeholders. Other articles were found by emailing authors and organisations to send potentially relevant publications. 19,500 articles were retrieved from bibliographic databases and 1281 from other sources. After iterative screening, 77 studies were included: 41 focussed on Africa, 22 on Asia, 12 on Latin America, 2 were global. Most indicators of food security measure access to food, measured by total consumption, expenditure, or income. Studies showed strong gender specialisation: commercial access and utilisation of forests and forest products dominated by men, whereas access for subsistence and household consumption is almost exclusively the task of women. Despite the large number of studies reviewed, limitations of the evidence base, including methodological heterogeneity, a dominance of case studies as the study design, and unequal geographical representation in study locations, make it difficult to generalise about the overall importance of gender and its effect on access to and use of forests for food security in developing countries. The critical gaps in the evidence base include geographical representation in primary research and a greater breadth of study designs to assess gender implications of access to forest resources globally

Effect of pH and pressure on uranium removal from drinking water using NF/RO membranes

International audienceGroundwater is becoming an increasingly important drinking water source. However, the use of groundwater for potable purposes can lead to chronic human exposure to geogenic contaminants, for example, uranium. Nanofiltration (NF) and reverse osmosis (RO) processes are used for drinking water purification, and it is important to understand how contaminants interact with membranes since accumulation of contaminants to the membrane surface can lead to fouling, performance decline and possible breakthrough of contaminants. During the current study laboratory experiments were conducted using NF (TFC-SR2) and RO (BW30) membranes to establish the behavior of uranium across pH (3-10) and pressure (5-15 bar) ranges. The results showed that important determinants of uranium membrane sorption interactions were (1) the uranium speciation (uranium species valence and size in relation to membrane surface charge and pore size) and (ii) concentration polarization, depending on the pH values. The results show that it is important to monitor sorption of uranium to membranes, which is controlled by pH and concentration polarization, and, if necessary, adjust those parameters controlling uranium sorption

Gradient‐enhanced TROSY described with Cartesian product operators

TROSY, Transverse Relaxation Optimized Spectroscopy, was developed more than a decade ago. Since that time, the 15 N‐ 1 H HSQC‐TROSY experiment has become the standard “fingerprint” correlation spectrum for proteins of high molecular weight. In addition, its implementation in protein triple resonance experiments has pushed the boundaries of NMR assignment up to about 100 kDa, making NMR a highly relevant technique in structural biology. TROSY exploits the dipole‐CSA cross‐correlated relaxation properties of the NH system and selects for the narrowest of the HSQC J‐correlation quartet in both dimensions. The original publications and reviews of TROSY use shift operators and/or single transition product operators to describe the TROSY coherence pathways selections. In this review, we offer a familiar Cartesian product operator approach to comprehensively describe all of the events in the modern TROSY pulse sequence such as multiplet selection, gradient coherence selection, gradient quadrature, and sensitivity enhancement. © 2011 Wiley Periodicals, Inc. Concepts Magn Reson Part A 38: 280–288, 2011.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88024/1/20228_ftp.pd

The Gendered Nature of Ecosystem Services

This is the final version. Available from Elsevier via the DOI in this record. This article assesses the extent to which our conceptualisation, understanding and empirical analysis of ecosystem services are inherently gendered; in other words, how they might be biased and unbalanced in terms of their appreciation of gender differences. We do this by empirically investigating how women and men are able to benefit from ecosystem services across eight communities in coastal Kenya and Mozambique. Our results highlight different dimensions of wellbeing affected by ecosystem services, and how these are valued differently by men and women. However, it is not just the division of costs and benefits of ecosystem services that is gendered. Using a heuristic device of the ‘ecosystem-wellbeing chain’ we explain patterns within our primary data as an outcome of gendered knowledge systems, gendered behavioural expectations, gendered access to resources and gendered institutions. We conclude that this holistic, gendered understanding of ecosystem services is important not just for how ecosystem services are conceptualised, but also for the development and implementation of sustainable and equitable policy and interventions.Natural Environment Research Council (NERC)Ecosystem Services for Poverty Alleviation (ESPA)Economic and Social Research Council (ESRC

The Gendered Nature of Ecosystem Services

This article assesses the extent to which our conceptualisation, understanding and empirical analysis of ecosystem services are inherently gendered; in other words, how they might be biased and unbalanced in terms of their appreciation of gender differences. We do this by empirically investigating how women and men are able to benefit from ecosystem services across eight communities in coastal Kenya and Mozambique. Our results highlight different dimensions of wellbeing affected by ecosystem services, and how these are valued differently by men and women. However, it is not just the division of costs and benefits of ecosystem services that is gendered. Using a heuristic device of the ‘ecosystem-wellbeing chain’, we explain patterns within our primary data as an outcome of gendered knowledge systems, gendered behavioural expectations, gendered access to resources and gendered institutions. We conclude that this holistic, gendered understanding of ecosystem services is important not just for how ecosystem services are conceptualised, but also for the development and implementation of sustainable and equitable policy and interventions

Quantum cellular automata quantum computing with endohedral fullerenes

We present a scheme to perform universal quantum computation using global addressing techniques as applied to a physical system of endohedrally doped fullerenes. The system consists of an ABAB linear array of Group V endohedrally doped fullerenes. Each molecule spin site consists of a nuclear spin coupled via a Hyperfine interaction to an electron spin. The electron spin of each molecule is in a quartet ground state $S=3/2$. Neighboring molecular electron spins are coupled via a magnetic dipole interaction. We find that an all-electron construction of a quantum cellular automata is frustrated due to the degeneracy of the electronic transitions. However, we can construct a quantum celluar automata quantum computing architecture using these molecules by encoding the quantum information on the nuclear spins while using the electron spins as a local bus. We deduce the NMR and ESR pulses required to execute the basic cellular automata operation and obtain a rough figure of merit for the the number of gate operations per decoherence time. We find that this figure of merit compares well with other physical quantum computer proposals. We argue that the proposed architecture meets well the first four DiVincenzo criteria and we outline various routes towards meeting the fifth criteria: qubit readout.Comment: 16 pages, Latex, 5 figures, See http://planck.thphys.may.ie/QIPDDF/ submitted to Phys. Rev.

On the C-determinantal range for special classes of matrices

Let A and C be square complex matrices of sizen, the C-determinantal range of A is the subset of the complex plane{det(A−UCU^∗): UU^∗=In}. If A, C are both Hermitian matrices, then by a result of Fiedler (1971)[11] this set is a real line segment. In our paper we study this set for the case when C is a Hermitian matrix. Our purpose is to revisit and improve two well-known results on this topic. The first result is due to Li concerning theC-numerical range of a Hermitian matrix, see Condition 5.1 (a) in Li, (1994)[20]. The second one is due to C.-K. Li, Y.-T. Poon and N.-S. Sze about necessary and sufficient conditions for the C-determinantal range of A to be a subset of the line, (see Li et al. (2008)[21], Theorem 3.3)

Extensive Neuronal Differentiation of Human Neural Stem Cell Grafts in Adult Rat Spinal Cord

BACKGROUND: Effective treatments for degenerative and traumatic diseases of the nervous system are not currently available. The support or replacement of injured neurons with neural grafts, already an established approach in experimental therapeutics, has been recently invigorated with the addition of neural and embryonic stem-derived precursors as inexhaustible, self-propagating alternatives to fetal tissues. The adult spinal cord, i.e., the site of common devastating injuries and motor neuron disease, has been an especially challenging target for stem cell therapies. In most cases, neural stem cell (NSC) transplants have shown either poor differentiation or a preferential choice of glial lineages. METHODS AND FINDINGS: In the present investigation, we grafted NSCs from human fetal spinal cord grown in monolayer into the lumbar cord of normal or injured adult nude rats and observed large-scale differentiation of these cells into neurons that formed axons and synapses and established extensive contacts with host motor neurons. Spinal cord microenvironment appeared to influence fate choice, with centrally located cells taking on a predominant neuronal path, and cells located under the pia membrane persisting as NSCs or presenting with astrocytic phenotypes. Slightly fewer than one-tenth of grafted neurons differentiated into oligodendrocytes. The presence of lesions increased the frequency of astrocytic phenotypes in the white matter. CONCLUSIONS: NSC grafts can show substantial neuronal differentiation in the normal and injured adult spinal cord with good potential of integration into host neural circuits. In view of recent similar findings from other laboratories, the extent of neuronal differentiation observed here disputes the notion of a spinal cord that is constitutively unfavorable to neuronal repair. Restoration of spinal cord circuitry in traumatic and degenerative diseases may be more realistic than previously thought, although major challenges remain, especially with respect to the establishment of neuromuscular connections