Factors Influencing the Evolution of Academic Dress at Kenyatta University, Kenya

Kenyatta University was established in 1985, as Kenya’s third university. It is based in Kahawa, which is a suburb of Nairobi, the capital city of Kenya. It is a modern institution, with well-equipped laboratories and other teaching facilities, state-of-the-art digital communications, including a fibre-optic cable network linking administrative and staff offices, and well-qualified teaching and administration staff. The declared aim of the management team is recognition as a ‘world class university’. However, in spite of the effort to achieve a modern image in teaching and research, the university has embraced the centuries-old tradition of wearing academic dress on certain occasions. [Excerpt]

A Check-list and identification key for succulent plants in general cultivation in Nairobi

Volume: 8

Digital Knowledge of Kenyan Succulent Flora and Priorities for Future Inventory and Documentation

Biodiversity inventory in Kenya has been ongoing for about a century and a half, coinciding with the arrival of naturalists from Europe, America, and elsewhere outside Africa. Since the first collections in the mid-to-late 1800s, there has been a steady increase of plant surveys, frequency of inventory, and discovery of new species that have considerably increased knowledge of faunal and floristic elements. However, as in all other countries, such historical biological collection activities are more often than not, ad hoc, resulting in gaps in knowledge of species and their habitats. While Kenya is relatively rich botanically, with a succulent flora of about 428 taxa, it is apparent that the list is understated owing to, among other factors, difficulty of preparing herbarium material and restricted access to some sites. This study investigated completeness of geographic knowledge of succulent plants in Kenya, with the aim of establishing species distribution patterns and identifying gaps that will guide and justify priority setting for future work on the group. Species data were filtered from the general BRAHMS database at the East African Herbarium and cleaned via an iterative series of inspections and visualizations designed to detect and document inconsistencies in taxonomic concepts, geographic coordinates, and dates of collection. Eight grid squares fulfilled criteria for completeness of inventory: one in the city of Mombasa, one in the Kulal–Nyiro complex, one in Garissa, one in Baringo, and four grid squares in the Nairobi–Nakuru–Laikipia area. Poorly-known areas, mostly in the west, north, and north-eastern regions of the country, were extremely isolated from well-known sites, both geographically and environmentally. These localities should be prioritised for future inventory as they are likely to yield species new to science, species new to the national flora, and/or contribute new knowledge on habitats. To avoid inconsistencies and data leakage, biodiversity inventory and documentation needs streamlining to generate standardised metadata that should be digitised to enhance access and synthesis

Ethnobotanical Uses of Sansevieria Thunb (Asparagaceae) in Coast Province of Kenya

Sansevieria Thunb. is a genus with diverse ethnobotanical uses in its geographical range. The current study reports on findings from an ethnobotanical study carried out on the genus Sansevieria in Coast Province of Kenya. Collating of ethnobotanical uses of Sansevieria from existing literature has been complicated by the fact that the ethnobotany of the genus is poorly documented with most species misidentified due to the nomenclatural confusion and the unresolved taxonomy of the genus Sansevieria. The aim of the current study was to correctly identify various Sansevieria species from their natural habitats and type localities where possible, to observe the plants in situ, and to document ethnobotanical uses of different Sansevieria species that occur in Coast Province of Kenya. Indigenous knowledge on the use of the plants by the local communities was captured by interviewing people residing in the study area. Purposive sampling and snow ball sampling were employed in the selection of informants. Direct observation, open ended, informal, and semi structured interviews covering questions on local names of species, plant uses, mode of administration, and the specific plant parts used were carried out with thirty respondents. Responses were documented for ethnobotanical uses of 9 Sansevieria species: S. conspicua N.E.Br., S. dumetescens L.E. Newton, S. fischeri (Baker) Marais, S. kirkii Baker, S. nitida Chahin., S. perrotii Warb., S. powellii N.E.Br., S. raffillii N.E.Br., and S. volkensii Gürke. A total of four broad use categories were identified from the study: medicinal use, horticultural use, food additives, and materials. Materials category was the most prevalent category with 49% of the total responses, followed by Medicinal category that accounted for 27%, the Horticultural use category that accounted for 21%, and the Food additives category that accounted for 3% of the total responses. The current study contributes to documentation of the ethnobotany of genus Sansevieria species in Coast Province of Kenya and provides a basis for a broader inquiry on the ethnobotany of genus Sansevieria based on wider sampling.

The uses of Kenyan aloes: an analysis of implications for names, distribution and conservation

Background The genus Aloe is renowned for its medicinal and cosmetic properties and long history of use. Sixty-three Aloe species occur in Kenya, of which around 50 % are endemic. Several species of aloes are threatened with extinction and knowledge about their use is of major importance for sound conservation strategies. The main aims of this study were to assess the biocultural value of Aloe in Kenya by documenting local uses of aloes and evaluating how the vernacular names reflect the relative importance in different ethnic groups. Methods Ethnobotanical and ethnotaxonomical data were collected using field observations and semi-structured interviews. Information was collected by interviewing 63 respondents from nine different ethnic groups, representing different ages, gender and occupations. Statistical analyses were performed using R version 3.1.2. Results A total of 19 species of Aloe were found in the study area, of which 16 were used. On the generic level Aloe was easily distinguished. At species level, the local and scientific delimitation were almost identical for frequently used taxa. Aloe secundiflora, with 57 unique use records was the most important species. The two most frequently mentioned Aloe treatments, were malaria and poultry diseases. In our study area neither age nor gender had a significant influence on the level of knowledge of Aloe use. Finally, no correlation was found between extent of use and people’s perception of decrease in local aloe populations. The aloes are highly appreciated and are therefore propagated and transported over large areas when people relocate. Conclusion Biocultural value is reflected in the ethnotaxonomy of Aloe in Kenya. Different ethnic groups recognise their most-valued Aloe at the genus level as “the aloe” and add explanatory names for the other species, such as the “spotted aloe” and the “one-legged aloe”. Widespread species of Aloe have the highest number of uses. There is no obvious correlation with high use and decrease in abundance of aloes locally, and we found no compelling evidence for local uses causing devastating damage to populations of the 19 species in use, whereas habitat loss and commercial harvesting appear to be of urgent concern for these important plants

Bostonia. Volume 11

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

The Core-Collapse Supernova Rate in Arp299 Revisited

We present a study of the CCSN rate in nuclei A and B1 of the luminous infrared galaxy Arp299, based on 11 years of Very Large Array monitoring of their radio emission at 8.4 GHz. Significant variations in the nuclear radio flux density can be used to identify the CCSN activity in the absence of high-resolution very long baseline interferometry observations. In the case of the B1-nucleus, the small variations in its measured diffuse radio emission are below the fluxes expected from radio supernovae, thus making it well-suited to detect RSNe through flux density variability. In fact, we find strong evidence for at least three RSNe this way, which results in a lower limit for the CCSN rate of 0.28 +/- 0.16 per year. In the A-nucleus, we did not detect any significant variability and found a SN detection threshold luminosity which allows only the detection of the most luminous RSNe known. Our method is basically blind to normal CCSN explosions occurring within the A-nucleus, which result in too small variations in the nuclear flux density, remaining diluted by the strong diffuse emission of the nucleus itself. Additionally, we have attempted to find near-infrared counterparts for the earlier reported RSNe in the Arp299 nucleus A, by comparing NIR adaptive optics images from the Gemini-N telescope with contemporaneous observations from the European VLBI Network. However, we were not able to detect NIR counterparts for the reported radio SNe within the innermost regions of nucleus A. While our NIR observations were sensitive to typical CCSNe at 300 mas from the centre of the nucleus A, suffering from extinction up to A_v~15 mag, they were not sensitive to such highly obscured SNe within the innermost nuclear regions where most of the EVN sources were detected. (abridged)Comment: 12 pages, 4 figures and 7 tables. Accepted for publication in MNRA

The motion of the 2D hydrodynamic Chaplygin sleigh in the presence of circulation

We consider the motion of a planar rigid body in a potential flow with circulation and subject to a certain nonholonomic constraint. This model is related to the design of underwater vehicles. The equations of motion admit a reduction to a 2-dimensional nonlinear system, which is integrated explicitly. We show that the reduced system comprises both asymptotic and periodic dynamics separated by a critical value of the energy, and give a complete classification of types of the motion. Then we describe the whole variety of the trajectories of the body on the plane.Comment: 25 pages, 7 figures. This article uses some introductory material from arXiv:1109.321

Core-collapse supernovae missed by optical surveys

We estimate the fraction of core-collapse supernovae (CCSNe) that remain undetected by optical SN searches due to obscuration by large amounts of dust in their host galaxies. This effect is especially important in luminous and ultraluminous infrared galaxies, which are locally rare but dominate the star formation at redshifts of z~1-2. We perform a detailed investigation of the SN activity in the nearby luminous infrared galaxy Arp 299 and estimate that up to 83% of the SNe in Arp 299 and in similar galaxies in the local Universe are missed by observations at optical wavelengths. For rest-frame optical surveys we find the fraction of SNe missed due to high dust extinction to increase from the average local value of ~19% to ~38% at z~1.2 and then stay roughly constant up to z~2. It is therefore crucial to take into account the effects of obscuration by dust when determining SN rates at high redshift and when predicting the number of CCSNe detectable by future high-z surveys such as LSST, JWST, and Euclid. For a sample of nearby CCSNe (distances 6-15 Mpc) detected during the last 12 yr, we find a lower limit for the local CCSN rate of 1.5 +0.4/-0.3 x 10^-4 yr^-1 Mpc^-3, consistent with that expected from the star formation rate. Even closer, at distances less than ~6 Mpc, we find a significant increase in the CCSN rate, indicating a local overdensity of star formation caused by a small number of galaxies that have each hosted multiple SNe.Comment: 16 pages, 5 figures, 11 tables, minor changes to match the published versio