843 research outputs found
Strengthening the Resiliency of Dryland Forest-Based Livelihoods in Ethiopia and South Sudan: A Review of Literature on the Interaction Between Dryland Forests, Livelihoods and Forest Governance
Dry forests account for nearly half of the world’s tropical and subtropical forests and provide a multitude of ecological services. They contribute to hydrological cycles and livestock and wildlife provisioning; and host pollinators and wild plants. They are also important ecological zones for dryland agriculture and pastoral livelihood strategies that support hundreds of millions of people around the world. Dry forests cover large areas and their biomass stores carbon and helps mitigate climate change. Dry forests are particularly important to people in Africa. They provide wood for construction and energy, contribute to local diets with wild fruits, vegetables, nuts, edible insects and bushmeat. Wild, edible plants provide essential nutrients, particularly during times of food scarcity. Yet dry forests are subject to high rates of deforestation and degradation driven mainly by agricultural expansion and growing energy demands. Other challenges include limited information on dry forests (their inventories, changes over time, major drivers of deforestation and recovery, etc.), their biophysical aspects and ecosystem services and the potential roles they could play in increasing the sustainability of crop and livestock farming. Governments, development partners and communities are looking for options to better manage these resources at the landscape level.
Dry forests are complex ecosystems that are not fully understood. Scientific knowledge to better manage dry forests and sustain the livelihoods of people that depend on these ecosystems remains scanty as research to inform policy and practice is still very limited. The knowledge gap is even more pronounced in northeastern Africa, notably Ethiopia and South Sudan where these forest types are important in terms of areas coverage and in supporting rural livelihoods. Ethiopia and South Sudan share histories of political unrest and conflict that have contributed to famines; large-scale land acquisition for investment and agricultural expansion by smallholders are resulting in major and rapid land-use changes in their dry forested areas. Ethiopia’s two decades of peace and stability and its experience in managing its natural resources could inform post-conflict intervention measures in South Sudan.
This study was conducted as an effort to help fill the knowledge gap in dry forest-based livelihoods through a critical review of the available literature. It used publications from CIFOR’s work on dry forests and product marketing in Ethiopia and from other sources, including gray literature. The study assessed the socio-ecological context, including relevant laws and strategies, with an emphasis on the biophysical characteristics of the dryland forests of Ethiopia and South Sudan and the major causes of deforestation and forest degradation. Using livelihood systems as an analytical framework, it examined (i) major livelihood strategies; (ii) the contribution of dry forests to livelihoods; (iii) forest product markets and value chains; and (iv) forest and land governance with an emphasis on the relationship between political, economic and resource management policies and the level of degradation of dry forests and their contributions to the livelihoods of forest-dependent communities in Ethiopia and South Sudan. It also identified major threats to dry, forest-based livelihoods and key issues for policy, research and practice that need to be addressed to maintain the multifunctionality of dryland forests while also ensuring the well-being of communities dependent on these landscapes
A comparison of the neuroprotective efficacy of newly developed oximes (K117, K127) and currently available oxime (obidoxime) in tabun-poisoned rats
The potency of newly developed bispyridinium compounds (K117, K127) to reduce tabun-induced acute neurotoxic signs and symptoms was compared with currently available oxime (obidoxime) using functional observational battery. The neuroprotective effects of atropine alone and atropine combined with one of three bispyridinium oximes (K117, K127, obidoxime) on rats poisoned with tabun at a sublethal dose (180 ÎĽg/kg i.m.; 80% of LD50 value) were studied. Tabun-induced neurotoxicity was monitored using a functional observational battery and automatic measurement of motor activity at 24 h following tabun challenge. The results indicated that all tested oximes combined with atropine enabled tabun-poisoned rats to survive 24 h following tabun challenge while one tabun-poisoned rats died within 24 h after tabun poisoning when the rats were treated with atropine alone. Newly developed oxime K127 combined with atropine was the most effective in decreasing tabun-induced neurotoxicity in the case of sublethal poisonings among all oximes tested. Nevertheless, the differences of neuroprotective efficacy between K127 and obidoxime are not sufficient to replace obidoxime by K127 for the treatment of acute tabun poisonings
Effects of cavity birefringence in polarisation-encoded quantum networks
The generation of entanglement between distant atoms via single photons is
the basis for networked quantum computing, a promising route to large-scale
trapped-ion and trapped-atom processors. Locating the emitter within an optical
cavity provides an efficient matter-light interface, but mirror-induced
birefringence within the cavity introduces time-dependence to the polarisation
of the photons produced. We show that such `polarisation oscillation' effects
can lead to severe loss of fidelity in the context of two-photon, polarisation
encoded measurement-based remote entanglement schemes. It is always preferable
to suppress these errors at source by minimising mirror ellipticity, but we
propose two remedies for systems where this cannot be achieved. We conclude
that even modest cavity birefringence can be detrimental to remote entanglement
performance, to an extent that may limit the suitability of
polarisation-encoded schemes for large-scale quantum networks.Comment: 18 pages, 8 figure
IMPACT OF CLIMATE CHANGE ON SMALL-HOLDER FARMING: A CASE OF EASTERN TIGRAY, NORTHERN ETHIOPIA
Although there are well-established concerns about climate change
effects in northern Ethiopia, there is little quantitative information
concerning how serious these effects are to small holder farming.
Moreover, studies on farm level adaptations that farmers make to
minimise the potential impacts of climate change are lacking. Both
quantitative and qualitative information were, therefore, collected in
a household survey in three representative agro-ecological zones to
investigate these problems. There was a general perception among rural
households that crop and livestock production, and land productivity
declined in the last 20 years. The reduction was related to changes in
rainfall. The rainfall was extremely unpredictable and erratic with a
coefficient of variation ranging from 18 percent in the midlands to 42
percent in the lowlands. Livestock holding size and crop yield showed a
positive correlation with rainfall amount. However, the number of pack
animals significantly increased regardless of the decreased rainfall
amount. This increased was due to farmers\u2019 shift to off-farm
activities.M\ueame si les probl\ue8mes li\ue9s aux effets du changement
climatique sont bien connus au Nord de l\u2019Ethiopie, les
informations en rapport avec l\u2019ampleur de ces effets sur les
petits exploitants restent insuffisantes. En plus, il n\u2019ya aucune
\ue9tude disponible sur les m\ue9canismes d\u2019adaptation que
les fermiers utilisent pour minimiser les impacts potentiels du
changement climatiques. Les donn\ue9es quantitatives et qualitatives
\ue9taient collect\ue9es au cours d\u2019une enquete de
m\ue9nages dans trois zones agro \ue9cologiques
repr\ue9sentatives, afin d\u2019\ue9tudier ces probl\ue8mes. Les
r\ue9sultats ont montr\ue9 que les fermiers per\ue7oivent
g\ue9n\ue9ralement que la production des cultures et
d\u2019\ue9levage ainsi que la productivit\ue9 des terres ont
diminu\ue9 depuis les 20 derni\ue8res ann\ue9es. Cette diminution
\ue9tait li\ue9e au changement dans la pluviom\ue9trie. La
pluviom\ue9trie \ue9tait extr\ueamement impr\ue9dictible et
erratique avec un coefficient de variation allant de 18% dans les
midlands \ue0 42% dans les bas fonds. La taille de la possession
d\u2019\ue9levage et le rendement des cultures ont montr\ue9 une
corr\ue9lation positive avec la quantit\ue9 des pluies. Cependant,
le nombre du b\ue9tail en stabulation a significativement
augment\ue9 malgr\ue9 la diminution des pluies. Cette augmentation
\ue9tait due \ue0 la cr \ue9 ation d\u2019autres activit \ue9
s non agricoles
Dryland restoration successes in the Sahel and Greater Horn of Africa show how to increase scale and impact
Drylands occupy more than 40% of the world’s land area and are home to some two billion people. This includes a disproportionate number of the world’s poorest people, who live in degraded and severely degraded landscapes. The United Nations Convention to Combat Desertification states on its website that 12 million hectares are lost annually to desertification and drought, and that more than 1.5 billion people are directly dependent on land that is being degraded, leading to US$42 billion in lost earnings each year. In Africa, three million hectares of forest are lost annually, along with an estimated 3% of GDP, through depleted soils. The result is that two-thirds of Africa’s forests, farmlands and pastures are now degraded. This means that millions of Africans have to live with malnutrition and poverty, and in the absence of options this further forces the poor to overexploit their natural resources to survive. This in turn intensifies the effects of climate change and hinders economic development, threatening ecological functions that are vital to national economies
Type of anaesthesia for caesarean section and failure rate in Princess Marina Hospital, Botswana\u2019s largest referral hospital
Background: Caesarean Section (CS) is a mode of delivery to decrease
maternal and perinatal morbidity and mortality. We aimed to determine
the type of anaesthesia used for CS among live-birth deliveries; and
the failure rate of spinal anaesthesia (SA) in Princess Marina Referral
Hospital, Botswana. Methods: Women who underwent CS from May-December
2017 were enrolled in the study. Data were recorded from anaesthesia
charts and abstracted using Excel spreadsheet. We established the type
of anaesthesia used, comparing the rate of elective versus emergency
indications, and failure rate of SA using STATA. Fisher\u2019s exact
test used to compare results. Results: Among 2775 live-birth
deliveries, 30.2% (837/2775) was by CS. Of those, 95.2% (797/837) had
had SA and 4.8% (40/837) were GA. Under SA, 27.4% (218/797) were
elective, and 72.6% (579/797) were emergency. Under GA 10% (4/40) were
elective and 90.0% (36/40) were emergency. The overall failure rate of
SA was 2% (16/813), that is 0.9% (2/220) for elective and 2.4% (14/593)
among emergency indications; Fisher\u2019s exact test p = 0.2959.
Conclusion: Our study demonstrated that single shot SA is the most
commonly preferred type of anaesthesia for both elective and emergency
CS. The overall failure rate of SA was less common in our settings than
previously reported
The major Ethiopian milksheds : an assessment of development potential
The development potential of 8 milksheds in Ethiopia was assessed and ranked for potential for value chain development, as part of the MIDD project. Major criteria for ranking were market potential, production potential, presence of services, and commercialization level of the value chain. Highest ranking milk sheds were Addis Abeba, Adama-Asella, and Bahir Dar–Gondar milksheds
Identification of Disease Resistance Parents and Genome-Wide Association Mapping of Resistance in Spring Wheat
The likelihood of success in developing modern cultivars depend on multiple factors, including the identification of suitable parents to initiate new crosses, and characterizations of genomic regions associated with target traits. The objectives of the present study were to (a) determine the best economic weights of four major wheat diseases (leaf spot, common bunt, leaf rust, and stripe rust) and grain yield for multi-trait restrictive linear phenotypic selection index (RLPSI), (b) select the top 10% cultivars and lines (hereafter referred as genotypes) with better resistance to combinations of the four diseases and acceptable grain yield as potential parents, and (c) map genomic regions associated with resistance to each disease using genome-wide association study (GWAS). A diversity panel of 196 spring wheat genotypes was evaluated for their reaction to stripe rust at eight environments, leaf rust at four environments, leaf spot at three environments, common bunt at two environments, and grain yield at five environments. The panel was genotyped with the Wheat 90K SNP array and a few KASP SNPs of which we used 23,342 markers for statistical analyses. The RLPSI analysis performed by restricting the expected genetic gain for yield displayed significant (p \u3c 0.05) differences among the 3125 economic weights. Using the best four economic weights, a subset of 22 of the 196 genotypes were selected as potential parents with resistance to the four diseases and acceptable grain yield. GWAS identified 37 genomic regions, which included 12 for common bunt, 13 for leaf rust, 5 for stripe rust, and 7 for leaf spot. Each genomic region explained from 6.6 to 16.9% and together accounted for 39.4% of the stripe rust, 49.1% of the leaf spot, 94.0% of the leaf rust, and 97.9% of the common bunt phenotypic variance combined across all environments. Results from this study provide valuable information for wheat breeders selecting parental combinations for new crosses to develop improved germplasm with enhanced resistance to the four diseases as well as the physical positions of genomic regions that confer resistance, which facilitates direct comparisons for independent mapping studies in the future
Renormalization of four-quark operators, effective theory, and the role of evanescent operators
We present, in the context of dimensional regularization, a prescription to
renormalize Feynman diagrams with an arbitrary number of external fermions.
This prescription, which is based on the original t'Hooft-Veltman proposal to
keep external particles in four dimensions, is particularly useful to define
the 'renormalization' (in the context of effective Lagrangian) of physical
four-quark operators without introducing any evanescent operator. The results
obtained for processes agree with those from the so-called
naive prescription, but disagree with the ones with the introduction of
evanescent operators in a renormalization group analysis. We also present an
explicit two loop calculation of the mixing of the evanescent operators with
the physical dimension five operators for the same processes. Particular
attention is paid to the unboundedness nature of such mixing and how a formal
finite transformation is effected to decouple. The inevitable mass dependence
of one of these schemes in the literature is pointed out as the cause for the
difference mentioned.Comment: 39 pages plain TeX and 10 Postscript figures available upon request,
McGill/ 94-14 and UM-TH-94-2
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