Aboveground Net Primary Productivity in Grazed and Ungrazed pastures: Grazing Optimisation Hypothesis or Local Extinction of Vegetation Species

The controversy that has surrounded herbivory studies in the last few decades prompted our investigation to establish the extent to which herbivore optimisation hypothesis or compensatory growth evidence is real. We used the traditional movable cage method to collect primary productivity data on herbage, functional groups and key individual grass species in various controlled large herbivore treatments in an east African savanna. The herbivore treatments in triplicate blocks included cattle, wild herbivores with and without mega herbivores and combinations of cattle and wild herbivores also with and without mega herbivores. The findings revealed that at herbage level, most grazed treatments (four out of five) had higher productivity than the ungrazed control and three showed grazing optimisation curve at sixth polynomial degree between monthly productivity and grazing intensity (1-g/ng). At functional group level forbs productivity was higher in the ungrazed control than in any of the grazed treatments while at individual grass species level _Themeda triandra_ productivity was higher in all grazed treatments than in ungrazed control. We conclude against presence of herbivore optimisation hypothesis at herbage, functional group and species level because of lack of attributable grazing effect in grazed treatments that matches complex ecological effects in the ungrazed treatment

Epidemiological and socio-legal overview

No Abstract

Challenges and Opportunities in Cassava Production among the Rural Households in Kilifi County in the Coastal Region of Kenya

In Kenya, food security and poverty alleviation are some of the most important factors that the country must address in order to achieve the vision 2030. Cassava has potential not only as food for humans, but also as feed for livestock and as a substrate for biofuel production.  Although various constraints have been reported to afflict farmers in cassava production, a base line survey in the study sites (Kilifi and Kaloleni) was necessary to identify specific constraints facing farmers in this region so as to identify areas of intervention in production and utilization. Lack of disease free planting materials was identified as one of the major constraints since cassava mosaic disease (CMD) and the cassava brown streak disease (CBSD) pose serious threats in yield losses. The two diseases are transmitted by vectors and by diseased planting materials and almost all the farmers obtain their planting materials from their neighbours thus aiding in disease dissemination and compounding the problem. There is need to enable the community produce quality cassava seed and operate sustained cassava business, integrate legumes into cassava cropping systems and create an innovative value addition chain for utilization of cassava. Eighty percent of Kenya is marginal area and cassava being drought tolerant can enable the potential of these areas to be tapped thus helping to deal with the persistent food insecurity which is a common feature in these areas. Key words: Cassava, cowpeas, cultivars, production constraints, utilizatio

Transforming Geo-Spatial Data to Web Map Service Solutions

No abstract availabl

High-frequency variability of bacterioplankton in response to environmental drivers in Red Sea coastal waters

Autotrophic and heterotrophic bacterioplankton are essential to the biogeochemistry of tropical ecosystems. However, the processes that govern their dynamics are not well known. We provide here a high-frequency assessment of bacterial community dynamics and concurrent environmental factors in Red Sea coastal waters. Weekly sampling of surface samples during a full annual cycle at an enclosed station revealed high variability in ecological conditions, which reflected in changes of major bacterioplankton communities. Temperature varied between 23 and 34°C during the sampling period. Autotrophic (Synechococcus, 1.7–16.2 × 104 cells mL−1) and heterotrophic bacteria (1.6–4.3 × 105 cells mL−1) showed two maxima in abundance in spring and summer, while minima were found in winter and autumn. Heterotrophic cells with high nucleic acid content (HNA) peaked in July, but their contribution to the total cell counts (35–60%) did not show a clear seasonal pattern. Actively respiring cells (CTC+) contributed between 4 and 51% of the total number of heterotrophic bacteria, while live cells (with intact membrane) consistently accounted for over 90%. Sequenced 16S rRNA amplicons revealed a predominance of Proteobacteria in summer and autumn (>40%) and a smaller contribution in winter (21–24%), with members of the Alphaproteobacteria class dominating throughout the year. The contribution of the Flavobacteriaceae family was highest in winter (21%), while the Rhodobacteraceae contribution was lowest (6%). Temperature, chlorophyll-a, and dissolved organic carbon concentration were the environmental variables with the greatest effects on bacterial abundance and diversity patterns

Red Sea SAR11 and Prochlorococcus Single-cell Genomes Reflect Globally Distributed Pangenomes

Evidence suggests many marine bacteria are cosmopolitan, with widespread but sparse strains poised to seed abundant populations under conducive growth conditions. However, studies supporting this "microbial seed bank" hypothesis have analyzed taxonomic marker genes rather than whole genomes/metagenomes, leaving open the possibility that disparate ocean regions harbor endemic gene content. The Red Sea is isolated geographically from the rest of the ocean and has a combination of high irradiance, high temperature, and high salinity that is unique among the oceans; we therefore asked whether it harbors endemic gene content. We sequenced and assembled single-cell genomes of 21 SAR11 (subclades Ia, Ib, Id, and II) and 5 Prochlorococcus (ecotype HLII) samples from the Red Sea and combined them with globally sourced reference genomes to cluster genes into ortholog groups (OGs). Ordination of OG composition could distinguish clades, including phylogenetically cryptic Prochlorococcus ecotypes LLII and LLIII. Compared with reference genomes, 1% of Prochlorococcus and 17% of SAR11 OGs were unique to the Red Sea genomes (RS-OGs). Most (83%) RS-OGs had no annotated function, but 65% of RS-OGs were expressed in diel Red Sea metatranscriptomes, suggesting they are functional. Searching Tara Oceans metagenomes, RS-OGs were as likely to be found as non-RS-OGs; nevertheless, Red Sea and other warm samples could be distinguished from cooler samples using the relative abundances of OGs. The results suggest that the prevalence of OGs in these surface ocean bacteria is largely cosmopolitan, with differences in population metagenomes manifested by differences in relative abundance rather than complete presence/absence of OGs.IMPORTANCE Studies have shown that as we sequence seawater from a selected environment deeper and deeper, we approach finding every bacterial taxon known for the ocean as a whole. However, such studies have focused on taxonomic marker genes rather than on whole genomes, raising the possibility that the lack of endemism results from the method of investigation. We took a geographically isolated water body, the Red Sea, and sequenced single cells from it. We compared those single-cell genomes to available genomes from around the ocean and to ocean-spanning metagenomes. We showed that gene ortholog groups found in Red Sea genomes but not in other genomes are nevertheless common across global ocean metagenomes. These results suggest that Baas Becking's hypothesis "everything is everywhere, but the environment selects" also applies to gene ortholog groups. This widely dispersed functional diversity may give oceanic microbial communities the functional capacity to respond rapidly to changing conditions

The Student Movement Volume 106 Issue 18: Spring, Strings, and Jeans: AU Composers Take the Stage

HUMANS Freshman Spotlight Interview: George Isaac, Interviewed by: Lauren Kim From Berrien Springs to Beirut - A Spring Break Mission Trip, Interviewed by: Irina Gagiu Student Workers Across Campus, Interviewed by: Grace No ARTS & ENTERTAINMENT Creative Spotlight: In Passing Podcast, Interviewed by: Megan Napod Signal Boost: Inventing Anna, Gabriela Francisco The 94th Academy Awards: Desert Sci-Fi, Kooky Westers, & much more, Solana Campbell NEWS Gym Class Heroes Challenge, Sion Kim Sunday Music Series: Andrews University Composers Concert, Andrew Pak The Election, Chris Ngugi IDEAS Is Carbon Capture the Key to Stopping Climate Change?. Lyle Goulbourne Learning to Focus: Navigating the Weird, Wacky Mind of A Sould Blessed with ADD or ADHD, Angelina Nesmith Silenced Chalk: Unheard Women in STEM, Alexander Navarro PULSE Hamil Day: Making a Holiday, T Bruggeman Spring at Andrews, Isabella Koh Unplugging from Social Media, Gloria Oh THE LAST WORD You Can\u27t Give What You Don\u27t Have: Fill Your Cup, Megan Napodhttps://digitalcommons.andrews.edu/sm-106/1017/thumbnail.jp

The Student Movement Volume 106 Issue 20: Waving Goodbye to the School Year: AFIA Musical Dazzles Audience

HUMANS Meet Your New AUSA President: Aya Pangusan, Interviewed by: Timmy Duado Meet Your New AUSA Senator-at-Large: Rock Choi, Interviewed by: Grace No Professor Spotlight: Dr. L. Monique Pittman, Interviewed by: Caryn Cruz Senior Spotlight: Joshua Pak, Interviewed by: Lauren Kim ARTS & ENTERTAINMENT Creative Spotlight: The Scoop Podcast, Interviewed by: Solana Campbell Return to Palau Documentary Premiers at AU, Megan Napod Write ON, Kaela McFadden NEWS Balikbayan, Homecoming, Chris Ngugi Terry Dodge Memorial, Scott Moncrieff Until We Meet Again: Farewell to Three AU Deans, Chris Ngugi IDEAS Does the total score of a college course have anything to do with a student\u27s motivation?, Robert Zhang The Pros and Cons of Taking a Gap Year, Gabriela Francisco You\u27ll Be Ready When You Get There, I Promise, Evin N. Musgrove PULSE Eggs, Gabriela Fransico Goodbye from the SM Staff Summer Plans, Gloria Oh To Find Your Worldview, T Bruggeman THE LAST WORD Butterflies and Anxiety: A Final Word, Alyssa Henriquezhttps://digitalcommons.andrews.edu/sm-106/1019/thumbnail.jp