1,003 research outputs found
Perceived challenges in business development of smallholder dairy farmers in three Malawian regions
Dairy farmers face various challenges in developing their businesses. The current literature identifies several constraints towards a more efficient dairy sector that relate mostly to on-farm management practices. The available studies analyze constraints mostly from the objective viewpoint of the researcher, whereas very little is known about what farmers themselves perceive to be challenging. To better understand the farmersβ perspective and what they perceive to be challenging, and how these challenges differ across regions, this paper builds on a survey of 529 dairy farmers in Malawi. In the survey, respondents were asked in an open question to name their three main challenges. Based on the responses, a three-level coding scheme was elaborated. Data were then coded by two researchers to ensure reliability of coding. Codes were then used to calculate relative frequencies for the different challenges and to perform chi-square tests to check for regional differences in frequencies. Results suggest that farmers perceive low milk price and milk yield, animal health, availability of feedstock, and the costs for drugs as the main challenges. The analysis also revealed that the challenges vary strongly between the three main regions in the country β Blantyre (south), Lilongwe (central), and Mzuzu (north). The perceived challenges reflect the different production systems in the regions. In Blantyre, dairy farming is low in intensity, and farmers thus perceive inputs, in particular the availability of fodder, as well as outputs, in particular milk yields more frequently as a challenge than farmers in Lilongwe and Mzuzu. In contrast, dairy farming in Lilongwe is the most intense. Accordingly, farmers in Lilongwe perceive costs, in particular for inputs such as mash and concentrates as major constraints. Farmers in Mzuzu, which is a rather remote region, consider a lack of assistance, in particular concerning extension services significantly more challenging than the farmers in the other two regions do. Considering these insights, development work and extensions services may be able to increase outcomes in the dairy sector by targeting the regional challenges.Keywords: Challenges, dairy production, smallholders, Malawi, qualitative study, region
Upwelling events, coastal offshore exchange, links to biogeochemical processes - Highlights from the Baltic Sea Sciences Congress at Rostock University, Germany, 19-22 March 2007
The Baltic Sea Science Congress was held at Rostock University, Germany, from 19 to 22 March 2007. In the session entitled"Upwelling events, coastal offshore exchange, links to biogeochemical processes" 20 presentations were given,including 7 talks and 13 posters related to the theme of the session.This paper summarises new findings of the upwelling-related studies reported in the session. It deals with investigationsbased on the use of in situ and remote sensing measurements as well as numerical modelling tools. The biogeochemicalimplications of upwelling are also discussed.Our knowledge of the fine structure and dynamic considerations of upwelling has increased in recent decades with the advent ofhigh-resolution modern measurement techniques and modelling studies. The forcing and the overall structure, duration and intensity ofupwelling events are understood quite well. However, the quantification of related transports and the contribution to the overall mixingof upwelling requires further research. Furthermore, our knowledge of the links between upwelling and biogeochemical processes is stillincomplete. Numerical modelling has advanced to the extent that horizontal resolutions of c. 0.5 nautical miles can now be applied,which allows the complete spectrum of meso-scale features to be described. Even the development of filaments can be describedrealistically in comparison with high-resolution satellite data.But the effect of upwelling at a basin scale and possible changes under changing climatic conditions remain open questions
Fatty fish and supplements are the greatest modifiable contributors to the serum 25-hydroxyvitamin D concentration in a multiethnic population
Objective: Because vitamin D synthesis is lower in a heavily pigmented skin than in a lighter skin, the relative contribution of determinants to the vitamin D concentration might differ between ethnic groups. The aim of this study was to assess the prevalence of vitamin D deficiency and the relative contribution of vitamin D consumption and exposure to sunlight to the vitamin D concentration in a multiethnic population. Design: Cross-sectional study. Patients A total of 613 adults aged 18-65 years from a random sample from general practices in the Netherlands (52 degrees N, 2003-05), stratified according to gender and ethnic group. Measurements Serum 25-hydroxyvitamin D [25(OH)D], PTH, ethnic group, sunlight exposure, consumption of foods and supplements rich in vitamin D. Results The prevalence (95% confidence interval) of vitamin D deficiency [serum 25(OH)D < 25 nmol/l] was higher in Turkish (41.3%; 32.5-50.1), Moroccan (36.5%; 26.9-46.1), Surinam South Asian (51.4%; 41.9-60.9), Surinam Creole (45.3%; 34.0-56.6), sub-Saharan African (19.3%; 9.1-29.5) and other adults (29.1%; 17.1-41.1) compared to the indigenous Dutch (5.9%; 1.3-10.5). Modifiable, significant determinants (standardized regression coefficients) for serum 25(OH)D concentration were: consumption of fatty fish (0.160), use of vitamin D supplements (0.142), area of uncovered skin (highest category 0.136; middle category 0.028), use of tanning bed (0.103), consumption of margarine (0.093) and preference for sun (0.089). We found no significant modification of ethnic group on the effect of sunlight determinants. Conclusion: Of the modifiable determinants, fatty fish and supplements are the greatest contributors to the serum 25(OH)D concentration in a multiethnic population.(aut. ref.
Line defects in epitaxial silicon films grown at 560 C
We present an investigation of line defects in epitaxially grown silicon layers using Secco defect etching and transmission electron microscopy TEM . 1 m thick layers were deposited onto Si 100 wafers at a substrate temperature of 560 C using electron cyclotron resonance chemical vapour deposition ECRCVD . Defect etching reveals a variety of etch pits related to extended defects. A detailed analysis of the orientations and shapes of etch pits related to line defects is carried out. Using this information it is then possible to assign different types of etch pits to line defects observed by TEM. The investigations show, that one type of defect are extended dislocations parallel to lt;112 gt;, while the direction of two other types are lt;110 gt; as well as lt;314 gt;, a direction uncommon for line defects in silico
Central role of Ξ±7 nicotinic receptor in differentiation of the stratified squamous epithelium
Several ganglionic nicotinic acetylcholine receptor (nAChR) types are abundantly expressed in nonneuronal locations, but their functions remain unknown. We found that keratinocyte Ξ±7 nAChR controls homeostasis and terminal differentiation of epidermal keratinocytes required for formation of the skin barrier. The effects of functional inactivation of Ξ±7 nAChR on keratinocyte cell cycle progression, differentiation, and apoptosis were studied in cell monolayers treated with Ξ±-bungarotoxin or antisense oligonucleotides and in the skin of Acra7 homozygous mice lacking Ξ±7 nAChR channels. Elimination of the Ξ±7 signaling pathway blocked nicotine-induced influx of 45Ca2+ and also inhibited terminal differentiation of these cells at the transcriptional and/or translational level. On the other hand, inhibition of the Ξ±7 nAChR pathway favored cell cycle progression. In the epidermis of Ξ±7β/β mice, the abnormalities in keratinocyte gene expression were associated with phenotypic changes characteristic of delayed epidermal turnover. The lack of Ξ±7 was associated with up-regulated expression of the Ξ±3 containing nAChR channels that lack Ξ±5 subunit, and both homomeric Ξ±9- and heteromeric Ξ±9Ξ±10-made nAChRs. Thus, this study demonstrates that ACh signaling through Ξ±7 nAChR channels controls late stages of keratinocyte development in the epidermis by regulating expression of the cell cycle progression, apoptosis, and terminal differentiation genes and that these effects are mediated, at least in part, by alterations in transmembrane Ca2+ influx
Sunlight exposure or vitamin D supplementation for vitamin D-deficient non-western immigrants: a randomized clinical trial
Summary: Vitamin D deficiency is very common in non-western immigrants. In this randomized clinical trial, vitamin D 800 IU/day or 100,000 IU/3 months were compared with advised sunlight exposure. Vitamin D supplementation was more effective than advised sunlight exposure in improving vitamin D status and lowering parathyroid hormone levels. Introduction: Vitamin D deficiency (25-hydroxyvitamin D [25(OH)D]<25 nmol/l) is common among non-western immigrants. It can be treated with vitamin D supplementation or sunlight exposure. Methods: To determine whether the effect of vitamin
Short-Course External Beam Radiotherapy Versus Brachytherapy for Palliation of Dysphagia in Esophageal Cancer: A Matched Comparison of Two Prospective Trials
Introduction: Short-course external beam radiotherapy
(EBRT) and intraluminal brachytherapy are both accepted
treatments for the palliation of dysphagia in patients with
incurable esophageal cancer. We compared the effects of
both treatments from two prospective studies.
Methods: We performed a multicenter prospective cohort
study of patients with metastasized or otherwise incurable esophageal cancer requiring palliation of dysphagia
from September 2016 to March 2019. Patients were
treated with EBRT in five fractions of 4 Gy. Data were
compared with all patients treated with a single brachytherapy dose of 12 Gy in the SIREC (Stent or Intraluminal
Radiotherapy for inoperable Esophageal Cancer) trial,
both between the original cohorts and between 1:1 propensity scoreβmatched cohorts. The primary end point
was an improvement of dysphagia at 3 months without
reintervention. The secondary end points included toxicit
Prevalence of vitamin D deficiency among Turkish, Moroccan, Indian and sub-Sahara African populations in Europe and their countries of origin: an overview
Public Health and primary carePrevention and community carePrevention, Population and Disease management (PrePoD
Bone pain and extremely low bone mineral density due to severe vitamin D deficiency in celiac disease
Case report A 29-year-old wheelchair-bound woman was presented to us by the gastroenterologist with suspected osteomalacia. She had lived in the Netherlands all her life and was born of Moroccan parents. Her medical history revealed iron deficiency, growth retardation, and celiac disease, for which she was put on a gluten-free diet. She had progressive bone pain since 2 years, difficulty with walking, and about 15 kg weight loss. She had a short stature, scoliosis, and pronounced kyphosis of the spine and poor condition of her teeth. Laboratory results showed hypocalcemia, an immeasurable serum25-hydroxyvitamin D level, and elevated parathyroid hormone and alkaline phosphatase levels. Spinal radiographs showed unsharp, low contrast vertebrae. Bone mineral density measurement at the lumbar spine and hip showed a T-score of -6.0 and -6.5, respectively. A bone scintigraphy showed multiple hotspots in ribs, sternum, mandible, and long bones. A duodenal biopsy revealed villous atrophy (Marsh 3C) and positive antibodies against endomysium, transglutaminase, and gliadin, compatible with active celiac disease. A bone biopsy showed severe osteomalacia but normal bone volume. She was treated with calcium intravenously and later orally. Furthermore, she was treated with high oral doses of vitamin D and a gluten-free diet. After a few weeks of treatment, her bone pain decreased, and her muscle strength improved. Discussion In this article, the pathophysiology and occurrence of osteomalacia as a complication of celiac disease are discussed. Low bone mineral density can point to osteomalacia as well as osteoporosis. Β© International Osteoporosis Foundation and National Osteoporosis Foundation 2011
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