84 research outputs found
Eliciting students' preferences for the use of their data for learning analytics. A crowdsourcing approach.
Research on student perspectives of learning analytics suggests that students are generally unaware of the collection and use of their data by their learning institutions, and they are often not involved in decisions about whether and how their data are used. To determine the influence of risks and benefits awareness on students’ data use preferences for learning analytics, we designed two interventions: one describing the possible privacy risks of data use for learning analytics and the second describing the possible benefits. These interventions were distributed amongst 447 participants recruited using a crowdsourcing platform. Participants were randomly assigned to one of three experimental groups – risks, benefits, and risks and benefits – and received the corresponding intervention(s). Participants in the control group received a learning analytics dashboard (as did participants in the experimental conditions). Participants’ indicated the motivation for their data use preferences. Chapter 11 will discuss the implications of our findings in relation to how to better support learning institutions in being more transparent with students about the practice of learning analytics
Eliciting students' preferences for the use of their data for learning analytics. A crowdsourcing approach.
Research on student perspectives of learning analytics suggests that students are generally unaware of the collection and use of their data by their learning institutions, and they are often not involved in decisions about whether and how their data are used. To determine the influence of risks and benefits awareness on students’ data use preferences for learning analytics, we designed two interventions: one describing the possible privacy risks of data use for learning analytics and the second describing the possible benefits. These interventions were distributed amongst 447 participants recruited using a crowdsourcing platform. Participants were randomly assigned to one of three experimental groups – risks, benefits, and risks and benefits – and received the corresponding intervention(s). Participants in the control group received a learning analytics dashboard (as did participants in the experimental conditions). Participants’ indicated the motivation for their data use preferences. Chapter 11 will discuss the implications of our findings in relation to how to better support learning institutions in being more transparent with students about the practice of learning analytics
COMPARATIVE ADVANTAGE OF THE EASTERN AND CENTRAL AFRICA IN THE COFFEE EXPORT SECTOR: THE CASE OF BURUNDI
Coffee is a major contributor to the economies of East African
Community (EAC) members. However, recently, export of the crop has
declined due to internal and external forces of supply and demand. This
paper sheds light on the EAC\u2019s comparative advantage in this cash
crop in the international coffee market, with a special focus on
Burundi, whose green coffee export is a backbone to its total exports
(75%). The study is based on the proposition of the trade theory that
partnership in international trade is determined by the prevailing
comparative advantage. An improved normalised comparative advantage
index, Normalised Revealed Comparative Advantage (NRCA), was used on
data of coffee exports of Standard International Trade Classification
(SITC) 3 4-grade, for the period 2000-2012. In order to conduct a
dynamic comparative analysis, we used a time trend regression model to
detect whether a country has gained or lost its comparative advantage
during the period under study. Instability analysis was also used to
depict the extent of NRCA volatility when the time trend was not
statistical significant. Empirical results reveal that EAC countries
had comparative advantage, with Uganda and Kenya leading the group
during the period under study. However, they exhibited a simultaneous
reduction in competitiveness in the global market, though at different
levels. For the ECA countries to remain competitive in the global
market, they must strengthen their position in the market by tackling
coffee price volatility at ^producer level and show willingness to
revamp the coffee industry.Le caf\ue9 est un grand support de l\u2019\ue9conomie des pays
membre de la Communaut\ue9 d\u2019Afrique de l\u2019Est (CAE).
Cependant, dans les p\ue9riodes r\ue9centes, les exportations de
cette culture industrielle a chut\ue9 a cause des facteurs tant
internes qu\u2019externes de l\u2019offre et de la demande. Cet
article a pour but de d\ue9gager le niveau de l\u2019avantage
comparatif des exportations de cette culture industrielle dans les pays
importateurs, avec un aper\ue7u sp\ue9cial sur le cas du Burundi
dont les exportations d\ue9pendent principalement du caf\ue9 (75
percent). Cette \ue9tude se base sur l\u2019hypoth\ue8se de la
th\ue9orie de l\u2019\ue9conomie internationale selon laquelle les
tendances du commerce international sont pr\ue9dites par
l\u2019avantage comparatif. L\u2019indicateur de l\u2019analyse de
l\u2019avantage comparatif, Avantage Comparatif R\ue9v\ue9l\ue9
Normalis\ue9 (NRCA) a servi \ue0 analyser NRCA sur les donn\ue9es
des exportations du caf\ue9 vert, SITC grade 3- 4, durant la
p\ue9riode de 2000-2012. Pour mener une analyse comparative
dynamique, nous avons utilis\ue9 le mod\ue8le de r\ue9gression de
tendance temporelle. Cette analyse nous a permis de savoir si le pays
en question a gagn\ue9 ou perdu son avantage comparatif durant la
p\ue9riode consid\ue9r\ue9e. L\u2019analyse
d\u2019instabilit\ue9 a \ue9t\ue9 adopt\ue9e afin de trouver
le d\ue9gr\ue9e de la volatilit\ue9 de NRCA lorsque la
r\ue9gression de tendance temporelle donnait des r\ue9sultats dont
les diff\ue9rences \ue9taient statistiquement non significatives.
Les r\ue9sultats empiriques ont montre que tous les pays membres de
la CAE pr\ue9sentent un certain avantage comparatif dans ce secteur
caf\ue9 avec le Kenya et l\u2019Uganda \ue0 la t\ueate du groupe
des pays pendant la p\ue9riode consid\ue9r\ue9e. N\ue9anmoins,
tous ont perdu leur avantage comparatif dans le march\ue9 mondial du
caf\ue9 durant la p\ue9riode en \ue9tude mais \ue0 des niveaux
relativement diff\ue9rents. Cet article a recommande que si les pays
de la CAE et sp\ue9cifiquement le Burundi, veulent \ueatre
comp\ue9titif sur le march\ue9 mondial du caf\ue9, ils doivent
r\ue9soudre l\u2019\ue9pineux probl\ue8me de la volatilite du
prix au producteur, mais aussi avoir la ferme volont\ue9
d\u2019acc\ue9l\ue9rer les politiques de restructuration du
secteur caf\ue9
Flowering and maturation periods of Finger Millet as influenced by phosphorus and variety in different agro-ecologies in Kenya
Phosphorus is important for finger millet production in many tropical African soils with low phosphorus fertility. Knowledge of redirection of this limited resource for reproduction is fundamental in realization of potential yields. The effect of four phosphorus levels (0, 12.5, 25.0 and 37.5 kg ha-1 P2O5) and three varieties (U-15, P-224 and a local check) on the days to flowering and maturity of finger millet were evaluated in three agro-ecologies in Kenya during the raining seasons of 2014-2015. Phosphorus application significantly (P<0.05) increased early flowering and physiological maturity in Kakamega and Busia. The varieties elicited significantly different days to 50% flowering and maturation periods in all the study sites. The days to flowering and maturity were found to be lowly but negatively correlated with the grain yield of finger millet in all the sites
Phosphorus influence on nitrogen uptake, nutrient and yield attributes of finger millet in semi-arid region of Kenya
An understanding of P efficiencies of finger millet is very important
in soil management and selection of varieties adaptable to
P-deficient soils. Therefore, on-station experiments were conducted
at the ICRISAT-Kiboko research station to evaluate the
effect of differential levels of P on nitrogen uptake, nutrient content
and yield. There were four P levels (0, 12.5, 25 and 37.5 kg
ha-1 P2O5) and three varieties (U-15, P-224 and Ekalakala). Ekalakala
was the local check while 0 kg/ha P2O5 was the control. The
trial was laid out in a randomized complete block design in factorial
arrangement with three replicates. Soil analytical results
showed moderately available P but very low N, organic carbon
and zinc. Significant differences (P<.05) were observed between
the phosphate levels on the nitrogen contents, where the control
had the lowest with 4.95% and 4.90% for the short and long
rains respectively; while the 25 kg ha-1 P2O5 rate had the highest,
with 5.66% in the short rains and 5.14% in the long rains. The
protein content significantly increased with phosphorus application,
peaking at 11.00 g/100 g on the 25 kg ha-1 P2O5treatment.
The newly released variety (U-15) responded positively to P
supplemented at 25 kg ha-1 P2O5 , with a maximum grain yield of
3,410 kg ha-1. It can, thus, efficiently utilize N in soils with low N
and is highly recommended. The application of P beyond 25 kg
ha-1 P2O5 would not be translated into profitable yields, but losses
to the farmer
Effect of Phosphate Levels on Soil Rhizosphere Nutrient Balances and Finger Millet Yield
Soil infertility is one of the main factors leading to low finger millet production in the semi-arid
tropics of Kenya. About 50-80% of P applied as fertilizer is adsorbed by soil and the amount of P
needed to achieve maintenance of its adequate status and influence on other soil properties has
not been well documented. An on-station experiment was therefore conducted at the KALROKiboko
research station during the 2014 long and 2015 short rain seasons to investigate the
influence of phosphorus rates on soil rhizosphere chemical properties and yield of three finger
millet varieties. The experiment was laid out in a Randomized Complete Block Design in factorial
arrangement and replicated three times. There were four P levels (0, 12.5, 25 and 37.5 kg ha-1
P2O5) and three varieties (U15, P-224 and local check-Kat FM1). Phosphorus application reduced
the soil pH significantly for both seasons with the 37.5 kg ha-1 P2O5 rate eliciting the greatest pH
from 9.26 to 7.90 (1.36 units) during the long rain season. As expected, soil phosphorus increased
with the highest rate with 11 ppm during the long rain season and 9 ppm for the short rains. The
organic carbon increased by 0.28% for the long rain season on the 25 kg ha-1 P2O5 rate while the
highest rate increased total N by 0.05%. The 25 kg ha-1 P2O5 rate and U-15 indicated the highest
yield for both seasons with a maximum of 3.71 t ha-1 realized during the short rain season.
Monitoring change in soil nutrient status is important for prescribing P fertilization in order to
maintain or replenish soil fertility. The application rate of 25 kg ha-1 P2O5 led to the optimal yields
under the improved variety and hence the study recommends this rate
Finger Millet (Eleusine coracana) Fodder Yield Potential and Nutritive Value under Different Levels of Phosphorus in Rainfed Conditions
Scarcity of fodder is the major limiting factor for increasing livestock production in Kenya. With rising energy costs and declining water levels in the semi-arid tropics and sub-tropics, crops that use less water like finger millet could become an alternate fodder crop. The fodder potential of three finger millet varieties (U-15, P-224 and a local check) were evaluated under four P fertilizer levels (0, 12.5, 25 and 37.5 kg ha-1 P2O5) at three sites in Kenya for two cropping seasons. The trials were laid in randomized complete block design in factorial arrangement and replicated three times. A maximum of 28,189 kg ha-1 fresh stover yield was realized in the 25 kg ha-1 P2O5 treatment and consequently 11,616 kg ha-1 dry stover yield. The 25 kg ha-1 rate elicited the highest fresh stover yield at Kakamega and Alupe for both seasons while at Kiboko a linear increase was observed on the stover yield with increasing rates where the highest rate had more than 15% yield compared to the control. The varieties also showed significant differences in all the sites with the local variety, Ikhulule, showing the highest fresh and dry stover yield at Kakamega and Alupe peaking at 28,852 and 12,826 kg ha-1 fresh and dry stover yields respectively. Interactions between variety and phosphorus rates were revealed on the crude protein content of the finger millet stover. At Kiboko, the highest crude protein (11.0%) on varieties P-224 and U-15 was exhibited at the highest rate while on the local variety, Ekalakala, the highest protein (10.9%) was realized at the 25 kg ha-1 P2O5. At Kakamega and Alupe, the highest protein was observed on the local variety, Ikhulule at 12.5 kg ha-1 P2O5 rate with variety P-224 and U-15 showing the highest at the 25 and 37.5 kg ha-1 P2O5 respectively. Therefore, finger millet can provide a unique opportunity to improve the availability of fodder to smallholder livestock farmers
Nitrogen and Phosphorus Uptake and Partitioning in Finger Millet as Influenced by Phosphorus Fertilization
Finger millet (Eleusine coracana) production in Eastern Africa remains low due to a variety of factors including soil nutrient depletion. As intensive row-crop production evolves, improvements in managing soil nutrient quantity and availability of less renewable nutrients like P becomes increasingly important. The yields in Kenya are typical of low input systems ranging below 1.0 t ha-1 against a potential of 5.0 t ha-1 in a season. In an attempt to overcome this constraint, On-station experiments were conducted at the Alupe research station during the long and short rain seasons of 2015 to investigate the influence of phosphate fertilizer rates (0, 12.5, 25 and 37.5 kg ha-1 P2O5) on nutrient uptake and partitioning in finger millet. Partitioning of N and P was significantly influenced (P30%) while the least to the roots (<19%). Variety U-15 had the greatest partitioning of nitrogen to the grains while the local variety, Ikhulule had the least. Application of phosphorus led to increase in the nitrogen and phosphorus uptake in finger millet with the most in the grains with a maximum of 106.5 kg ha-1 on the 37.5 kg ha-1 P2O5 rate during the short rains while the roots had the lowest uptake with 16.9 kg ha-1 and 22.1 kg ha-1 in the long and short rains seasons respectively on the control. This study on nutrient use provides an opportunity to further improve P fertilization to specific rates in relation to crops needs as farmers will be assured of greater yields, profitable and sustainable production. Limited use of P fertilizer restricts the uptake of phosphorus and nitrogen as well as the balance in partitioning and recommends application of 25 kg ha-1 P2O5 with improved varieties
Finger millet (Eleusine coracana L.) grain yield and yield components as influenced by phosphorus application and variety in Western Kenya
Finger millet is one of the potential cereal crops that can contribute to the efforts of
realization of food security in the Sub-Saharan Africa. However, scientific information available
with regards to improving soil phosphorus supply and identification of P efficient varieties for the
crops potential yield is limited. In order to investigate the effects of P levels on yield components
and grain yield On-station field experiments were conducted in two sites of western Kenya during
the long and short rain seasons of 2015. The experiment was laid out in a Randomized Complete
Block Design in factorial arrangement with four levels of P (0, 12.5, 25 and 37.5 kg P2O5 ha-1 and
three finger millet varieties (U-15, P-224 and a local check-Ikhulule) and the treatments replicated
three times. The increase of phosphorus levels significantly (P≤0.05) increased the grain yield
over the control up to 25 kg P2O5 ha-1 during the long rain seasons and 25 kg P2O5 ha-1 during the
short rain seasons in both sites. Interactions at P≤0.05 were revealed on the grain yield where
improved variety P-224 at 25 kg P2O5 ha-1 produced the highest grain yield of 4.74 t.ha-1 in Alupe
and 4.77 t.ha-1 in Kakamega and the consistent results suggest that the combination is highly
recommended. Therefore the use of judicious and proper rates of P fertilizers can markedly
increase the grain yield of finger millet in western Kenya
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