Articles: Postgraduate student articles
http://repository.embuni.ac.ke/handle/embuni/2154
Collection of journal articles authored by University of Embu Postgraduate students2024-03-29T08:53:02ZAperture Maximization with Half-Wavelength Spacing, via a 2-Circle Concentric Array Geometry that is Uniform but Sparse
http://repository.embuni.ac.ke/handle/embuni/2166
Aperture Maximization with Half-Wavelength Spacing, via a 2-Circle Concentric Array Geometry that is Uniform but Sparse
Kinyili, Musyoka; Kitavi, Dominic M.; Ngari, Cyrus G.
This paper proposes a new sensor-array geometry (the 2-circle concentric array geometry),
that maximizes the array's spatial aperture mainly for bivariate azimuth-polar resolution of
direction-of-arrival estimation problem. The proposed geometry provides almost invariant
azimuth angle coverage and o ers the advantage of full rotational symmetry (circular invariance)
while maintaining an inter-sensor spacing of only an half wavelength (for non-ambiguity with
respect to the Cartesian direction cosines). A better-accurate performance in direction nding
of the proposed array grid over a single ring array geometry termed as uniform circular array
(UCA) is hereby analytically veri ed via Cram er-Rao bound analysis. Further, the authors
demonstrate that the proposed sensor-array geometry has better estimation accuracy than a
single ring array.
2019-05-01T00:00:00ZBehavioural Patterns and Responses to Human Disturbances of Wild Somali Ostriches (Struthio molybdophanes) in Samburu, Kenya.
http://repository.embuni.ac.ke/handle/embuni/2165
Behavioural Patterns and Responses to Human Disturbances of Wild Somali Ostriches (Struthio molybdophanes) in Samburu, Kenya.
Mutiga, Mariciano Iguna; Muoria, Paul Kimata; Kotut, Kiplagat; Karuri, Hannah W.
Somali ostrich has suffered a drastic decline in its population and range mainly due to hunting over the years for meat, skin and feathers. Urgent conservation measures should therefore be taken to reverse this trend particularly in their current population stronghold, the Samburu landscape. In this range, the magnitude and consequences of human disturbance on the ostrich has not been established. The aim of this study was therefore to investigate the behavioural patterns and assess the impacts of human disturbance to the bird. Focal animal sampling was used to establish ostrich‟s behavioural activity budget while the magnitude of human disturbance was assessed by determining and comparing flight initiation distances in the protected and partially protected areas. Somali ostrich spent most of their diurnal time in feeding and moving, and are more sensitive to human disturbance in the protected areas than they are in the partially protected areas. The results of this study imply that the ratite does not differ in behavioural patterns from other extant ostrich species and human disturbance is not posing a significant threat to its survival within Samburu landscape. Further studies are recommended for better understanding of the conservation status of the newly published species.
2016-08-01T00:00:00ZFrom Shiny Shoes to Muddy Reality: Understanding How Meso-State Actors Negotiate the Implementation Gap in Participatory Forest Management
http://repository.embuni.ac.ke/handle/embuni/2164
From Shiny Shoes to Muddy Reality: Understanding How Meso-State Actors Negotiate the Implementation Gap in Participatory Forest Management
Kairu, Anne; Upton, Caroline; Huxham, Mark; Kotut, Kiplagat; Mbeche, Robert; Kairo, James
Recent research on participatory forest management (PFM) in the
global south has highlighted the existence of a widespread
“implementation gap” between the ambitious intent enshrined in
legislation and the often partial, disappointing rollout of devolved
forest governance on the ground. Here, through an ethnographic case
study of forest officers (FOs) in Kenya, we draw on a framework of
critical institutionalism to examine how key meso-level actors, or
“interface bureaucrats,” negotiate and challenge this implementation
gap in everyday forest governance. We go beyond consideration of
institutional bricolage in isolation or as an aggregate category, to
analyze how bricolage as aggregation, alteration, and/or articulation is
variously driven, shaped, and constrained by FOs’ multiple accountabilities
and agency. Our analysis highlights the locally specific,
contingent, and mutually reinforcing nature of accountability, agency
and bricolage, and their explanatory power in relation to the
performance and nature of “actually existing” PFM.
2017-11-01T00:00:00ZTomato Leaf miner (Tuta absoluta) (Meyrick 1917) (Lepidoptera: Gelechiidae) prevalence and farmer management practices in Kirinyanga County, Kenya
http://repository.embuni.ac.ke/handle/embuni/2163
Tomato Leaf miner (Tuta absoluta) (Meyrick 1917) (Lepidoptera: Gelechiidae) prevalence and farmer management practices in Kirinyanga County, Kenya
Nderitu, Peris Wangari; Muturi, Jamleck; Otieno, Mark; Arunga, Ester E.; Mattias, Jonsson
Pest invasion is one of the limiting factors affecting food production. Tomato leaf miner (Tuta absoluta)
(Meyrick 1917) (Lepidoptera: Gelechiidae), is an invasive insect pest of tomato. However, In Kenya,
there is limited information on the level of invasion of the pest in tomato producing areas in the
country. We assessed the level of invasion of T. absoluta and farmer management practices in
Kirinyaga County. Tomato farmers were interviewed using questionnaires aimed at identifying the
management practices used by farmers to control T. absoluta and their awareness on the insect pest.
Two hundred and eight tomato farmers were interviewed, 90% of the respondents rated T. absoluta as a
major pest of tomato. Results show that 94% of the respondents use synthetic chemicals in the control
of T. absoluta with an average frequency of 12 times per growing season of three months with the
highest frequency being 16 times. Increased use of synthetic insecticides was associated with a
negative impact on the natural enemies. Among the interviewed farmers, 52 and 46% of respondents
stated that after chemical spraying natural enemies disappear and are killed respectively, while 2% did
not know what happened to them. It is therefore imperative to design an integrated pest management
program that integrates biological control and environmentally friendly chemicals for sustainable
control of T. absoluta populations.
2018-08-01T00:00:00Z