537 research outputs found
Knowledge, education and social differentiation amongst the Betsileo of Fisakana, highland Madagascar
This thesis is an ethnographic study of a village in Fisakana, an area of highland Madagascar where the institution of formal education has had great social, economic and cultural influence.
Although the principal means of subsistence in Fisakana is wet rice cultivation, a severe shortage of good land has led to large-scale emigration. Schooling has provided opportunities for social and spatial mobility that have shaped the character of the region.
Migration and movement are dominant themes in the ethnography of Madagascar. The thesis examines three different types of migration in Fisakana. Each entails a different type of relationship between the migrants and their ancestral land. These are discussed in the context of other literature dealing with this topic in the anthropology of Madagascar.
The region is characterised by inequalities of wealth. People working in the profession sector have prospered economically in comparison to those dependent on agriculture. This thesis makes an original contribution to the literature on social and economic differentiation in the highlands by treating the subject from an ethnographic perspective. The role of formal education in widening socio-economic differentiation is explored in detail. Then the thesis studies how this differentiation is elaborated symbolically through the building of houses and tombs. it also points out the ambiguous nature of tomb ceremonies: whilst ostensibly symbolising social unity and cohesion, they also imply fissure and exclusion.
The thesis then examine the Betsileo social construction of knowledge. Through an exploration of what is learned inside and outside the classroom the thesis shows how local notions of traditional and foreign knowledge articulate with missionary, colonial and post-colonial ideologies of schooling, and with the social and spatial differentiation and displacement produced by formal education
A Study of Short-Season Winter Cover Crops for Organic High Tunnel Production Systems
This two-year study investigated short-season winter cover crops to improve soil quality and growth of subsequent vegetable crops in an organic high tunnel production system. Five winter cover crop treatments including a nontreated control, Austrian winter peas (Pisum arvense), bell beans (Vicia faba), mustard (Brassica juncea cv. Kodiak), and Daikon radish (Raphanus sativus var. longipinnatus) were grown in a high tunnel in a randomized complete block design from mid-November to mid-March, mowed and incorporated into the soil, and followed by a succession of vegetable crops including tomato (Lycopersicon lycopersicum, cv. âPlum Dandyâ) and broccoli (Brassica oleracea var. italica, cv. âBay Meadowsâ). In 2014 winter peas yielded the greatest above-ground biomass (284 g/m2), though in 2015 mustard and radish cover crops yielded greater above-ground biomass (424 g/m2 and 395 g/m2, respectively). Across both years winter peas contained the highest foliar N concentration (3.8%) and resulted in the greatest biomass N contribution, at an average of 10.2 g N/m2. The N contribution from winter pea resulted in a significantly lower soil C:N ratio 30 days after incorporation. Cover crop treatments did not result in significant changes to soil quality variables including soil organic matter, pH, and EC, though changes were observed over time across all treatments. The winter pea cover crop resulted in greater tomato leaf chlorophyll estimates than the nontreated control across both years, greater tomato foliar N concentration than all other treatments in 2015, and greater tomato plant biomass compared to the control. Though statistical differences were not detected due to high background variation, the winter pea cover crop resulted in a 48% increase in mean tomato yield compared to the control. Broccoli plant biomass was significantly greater following winter pea and radish cover crop treatments compared to the control (808 g/plant and 726 g/plant, respectively, compared to 600 g/plant), however cover crop treatments were not found to significantly affect broccoli harvest variables. Overall findings point to a cumulative effect of cover cropping on soil quality and vegetable crop production in a high tunnel, though the two-year timeline of this project limited the ability to understand long-term effects
The effects of shade on primocane fruiting blackberries in the field
Primocane fruiting blackberry production in Arkansas is limited by heat during the flowering and early fruiting season. Shade could be used to delay flowering and fruiting to more favorable growth period. This study was designed to test three levels of shade (0% [control], 30% and 50% shading) applied at three times during the growing season that examined the growth, development, physiology of flowering, and fruiting of âPrime-ArkÂź 45â blackberries. The seven treatments were as follows: 1) an untreated control (CK), 2) early shade 30% (ES30), mid shade 30% (MS30), 4) late shade 30% (LS30), 5) early shade 50% (ES50), 6) mid shade 50% (MS50), and 7) late shade 50% (LS50). The 30% and 50% treatments were implemented 16 June (ES) and left on for 95 days, 1 July (MS) and left on for 80 days, and 15 July (LS) and left on for 66 days. All shade was removed 19 Sept. 2014. Foliar gas exchange using CIRASÂź-3 portable gas exchange monitor and estimated chlorophyll content (Minolta SPADÂź) were measured weekly. Beginning at maturity, fruit was harvested biweekly to determine fruit yields per plot. Plant growth was measured destructively at the end of the study period. The cumulative berry weight was greatest for LS50 and LS30 which was not different from the CK or MS50, while ES30, MS30, and ES50 berry weights were significantly less. The cumulative marketable weights were greatest for LS30 and CK, while ES30 and MS30 were less than the CK. Shade altered flower and fruit production, but was not found to result in higher fruit quantities compared to the control. Some ES treatments reduced cropping compared to LS treatments
Transformer-Based Learned Optimization
We propose a new approach to learned optimization where we represent the
computation of an optimizer's update step using a neural network. The
parameters of the optimizer are then learned by training on a set of
optimization tasks with the objective to perform minimization efficiently. Our
innovation is a new neural network architecture, Optimus, for the learned
optimizer inspired by the classic BFGS algorithm. As in BFGS, we estimate a
preconditioning matrix as a sum of rank-one updates but use a Transformer-based
neural network to predict these updates jointly with the step length and
direction. In contrast to several recent learned optimization-based approaches,
our formulation allows for conditioning across the dimensions of the parameter
space of the target problem while remaining applicable to optimization tasks of
variable dimensionality without retraining. We demonstrate the advantages of
our approach on a benchmark composed of objective functions traditionally used
for the evaluation of optimization algorithms, as well as on the real
world-task of physics-based visual reconstruction of articulated 3d human
motion.Comment: Accepted to the IEEE/CVF Conference on Computer Vision and Pattern
Recognition 2023 (CVPR) in Vancouver, Canad
Effect of timing of shade on growth, development, physiology, and fruiting of a primocane fruiting blackberry in a controlled environment
Primocane blackberry production in the upper south is limited by high temperatures during the bloom and early fruiting period, resulting in poor fruit set and poor fruit quality. Shade may have the potential to delay bloom and flowering to a more favorable season. A greenhouse study was established to evaluate the effects of shade on primocane blackberry growth, physiology, and fruiting. Single rooted plants of âPrime-ArkÂź 45â were planted in 12-liter pots and grown in a greenhouse at the University of Arkansas System Division of Agriculture, Agriculture Research and Extension Center, Fayetteville, Arkansas. At approximately 0.25 m in height, one of the four following treatments was imposed with eleven single plant replications: 1) an untreated control (CK), 2) unshaded for 29 days then shaded for 30 days (US), 3) shaded for 29 days then shaded for 30 days (SS), and 4) shaded for 29 days and unshaded for 30 days (SU). Plants in the SU treatment were significantly taller than the SS and CK. Dry weight of leaves was consistent for all treatments except for SS which was significantly lower than the others. The CK bloomed first followed by US and SS. The last to bloom was the SU, 26 days after the CK. In conclusion, there was a delay of âPrime-Ark 45â flower formation when 50% shade cloth was implemented and removed in the SU treatment. Further research needs to be completed to find the optimal intensity and timing of shade implementation that will improve fruit set in the southern region
Clinical and cost-effectiveness of internal limiting membrane peeling for patients with idiopathic full thickness macular hole. Protocol for a Randomised Controlled Trial : FILMS (Full-thickness macular hole and Internal Limiting Membrane peeling Study)
Background: A full-thickness macular hole (FTMH) is a common retinal condition associated with impaired vision. Randomised controlled trials (RCTs) have demonstrated that surgery, by means of pars plana vitrectomy and post-operative intraocular tamponade with gas, is effective for stage 2, 3 and 4 FTMH. Internal limiting membrane (ILM) peeling has been introduced as an additional surgical manoeuvre to increase the success of the surgery; i.e. increase rates of hole closure and visual improvement. However, little robust evidence exists supporting the superiority of ILM peeling compared with no-peeling techniques. The purpose of FILMS (Fullthickness macular hole and Internal Limiting Membrane peeling Study) is to determine whether ILM peeling improves the visual function, the anatomical closure of FTMH, and the quality of life of patients affected by this disorder, and the cost-effectiveness of the surgery.
Methods/Design: Patients with stage 2â3 idiopathic FTMH of less or equal than 18 months duration (based on symptoms reported by the participant) and with a visual acuity †20/40 in the study eye will be enrolled in this FILMS from eight sites across the UK and Ireland. Participants will be randomised to receive combined cataract surgery (phacoemulsification and intraocular lens implantation) and pars plana vitrectomy with postoperative intraocular tamponade with gas, with or without ILM peeling. The primary outcome is distance visual acuity at 6 months. Secondary outcomes include distance visual acuity at 3 and 24 months, near visual acuity at 3, 6, and 24 months, contrast sensitivity at 6 months, reading speed at 6 months, anatomical closure of the macular hole at each time point (1, 3, 6, and 24 months), health related quality of life (HRQOL) at six months, costs to the health service and the participant, incremental costs per quality adjusted life year (QALY) and adverse events.
Discussion: FILMS will provide high quality evidence on the role of ILM peeling in FTMH surgery.
Trial registration: This trial is registered with Current Controlled Trials ISRCTN number 33175422 and Clinical Trials.gov identifier NCT00286507.Chief Scientist Office, Scotland (project ref no CZH/4/235), NHS GrampianPeer reviewedPublisher PD
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