In pursuit of the heteroxyly hypothesis: Sharing tasks between xylem tissues for performance implementation
Speaker: Aritsara Amy Ny Aina (College of Forestry, Guangxi University, China)
Date/Time: Tue, 12 Nov 2019, 4 pm
Venue: DBS Conference Room 1 (Block S3 Level 5)
Growing skywards implies that trees have to deal with different kinds of constraints: mechanical support, water transport, resource storage, etc. The heteroxyly hypothesis states that sharing those functions among specialized tissues is more efficient than multifunctional tissues. My study mainly focuses on xylem parenchyma and its contribution to plant hydraulic safety and efficiency. In palms, the ground parenchyma, with its high storage capacity, is vital for the plant to escape from the constraints due to the theoretical vessel tapering and to optimize their water transport efficiency. In basal angiosperms, the axial parenchyma has been believed to hold space and to use large amounts of resources for maintenance, hence trading-off with hydraulic efficiency and safety. However, our findings suggest that it coordinates with the optimization of water transport. In the new era of changing climates, would a xylem with more parenchyma tissue guarantee higher survivorship against environmental stochasticity?
All are welcome.
Speaker: Sean Yap (Graduate Student, Dept. of Biological Sciences, NUS)
Date/Time: Thursday, 7 November 2019: 9.30am
Venue: S3-05-02, DBS Conference Room (S3 Level 5)
Supervisor : Dr Nalini Puniamoorthy
Southeast Asia is biodiversity rich, but the role of reproductive isolation via mechanisms of sexual selection remains largely unexplored. Here, we aim to investigate the potential role of sexual selection in reproductive diversification of dung beetles in SEA.
Dung beetles are an incredibly species rich group and provide key ecosystem services in forested and agricultural communities. Globally, these insects are excellent models to investigate speciation by sexual selection because most species and even populations might exhibit stark differences in pre- and postcopulatory sexual traits. However, little is known about reproductive diversification of dung beetles in SEA. There are incomplete records on regional biodiversity and little to no information about genetic structure among widespread populations and morphological variation within species, especially with respect to traits that might establish reproductive barriers to gene flow.
Thus, this research aims to address four complementary research questions to study reproductive evolution in local and regional dung beetle fauna, focusing on two main genera, Onthophagus and Catharsius:
- What are the morphological and molecular estimates of dung beetle biodiversity in the region?
- Is postcopulatory sexual selection driving incipient speciation in the Catharsius molossus species complex?
- Do widespread populations of Onthophagus species differ in sexual selection across SEA?
- Does nematode diversity and load increase with the intensity of sexual selection across species and populations?
All are welcome.
Nepenthes: A Model System for the Study of Resource-Mediated Interspecific Interactions
Speaker: Lam Weng Ngai (Graduate Student, Dept. of Biological Sciences, NUS)
Date/Time: Friday, 8 November 2019: 9.00am
Venue: S3-05-02, DBS Conference Room (S3 Level 5)
Supervisor: A/P Tan Tiang Wah, Hugh
Carnivorous pitcher plants of the genus Nepenthes bear modified leaves which employ pitfall trap-type mechanisms to capture and digest invertebrate prey. Nutrients obtained from these prey allow Nepenthes to survive in environments that are deficient in these resources. The fluid-filled traps of Nepenthes are also habitats for specialized aquatic organisms known as inquilines, which have been shown to facilitate prey carcass breakdown and thus nutrient sequestration in Nepenthes pitchers.
In this thesis, I use Nepenthes pitcher plants as a model to investigate key topics in ecology relating to interspecific interactions, namely coexistence, facilitation and context dependency.
My thesis is divided into two sections. The first investigates resource-based interactions within this diverse plant genus—specifically, resource competition and facilitation between Nepenthes species—and establishes the key premise of prey resource limitation in Nepenthes species.
The second conditions upon this established premise, but focuses instead on the resource-mediated interactions between the Nepenthes host and its inquilines. Findings of the second section lead me to postulate a previously unexplored mechanism behind resource-mediated positive species interactions.
In the final chapter of the thesis, I investigate this mechanism by formulating a generalizable, consumer-resource type model of what I term as “resource conversion interactions”. Predictions of this model are compared with earlier empirical findings, and synthesis across the whole thesis is attempted.
All are welcome.
Advert from NParks
Sungei Buloh Wetland Reserve (SBWR) is a branch under the Conservation Division in NParks which is responsible for safeguarding our Nature Reserves and Nature Parks.
SBWR is seeking interns who wish to have a unique opportunity in experiencing various management practices to preserve the ecological health of Singapore’s most famous mangrove and wetland reserve. More specifically the intern will join our Communication, Education and Public Awareness (CEPA) program team.
The job scope includes:
- Assist or lead signature outreach events and programmes unique to SBWR
- Design outreach collaterals for various public and educational groups
- Public and volunteers engagement to raise awareness for wetland conservation
- Logistics preparations
This internship is suitable for someone who has deep passion for nature conservation, enjoys engaging people, a team player, and has an aptitude for developing outreach activities and materials creatively. Ideally the internship is for five to six months (eg. LSM4299 students), but we can consider other internship duration.
If you have desire in contributing to the conservation cause, please contact Robin Ngiam (firstname.lastname@example.org) or Florence Sim (email@example.com) for an interview.
The successful applicant is required to support programmes that promote collaboration and partnerships in conserving Singapore’s natural heritage. Examples of programmes include NParks Community in Nature (CIN) Biodiversity Watches, Festival of Biodiversity and CIN school programmes.
- Developing, organising and conducting outreach programmes.
- Creating suitable materials for these programmes.
- Assisting in research and field trips.
- Managing logistics and other administrative duties.
- Processing of data collected by citizen scientists.
Any Other Requirements (e.g. to indicate preference for students’ course)
- Strong background in biological sciences or related discipline.
- Good interpersonal, written and communication skills, with the ability to influence and motivate others.
- Familiarity with online medium, audio and visual equipment, for the development of educational materials.
- An organised, creative and resourceful team player who can meet deadlines.
- Keen interest in nature conservation and outreach and enjoys working in an outdoor environment.
- Proficiency in nature photography, film production or design-related media (e.g. Adobe Photoshop, Illustrator) is a plus.
Apply with the following documents to CIN@nparks.gov.sg with the subject: 2020 FYI Application
- Cover letter
- Photography, film or design-related portfolio, if any
More information available in this document: BIP-FYI-Internship-info_2019_2020.pdf
Visit the NUS DBS webpage for details.
The Centre for International Law, NUS, is looking for a Research Assistant for a multi-disciplinary research project on marine international law and policy, marine sciences and pollution from marine plastics
Full-time or part-time position of Research Assistant
This is a 3-months position starting 1 Oct 2019-31 Dec 2019 to support completion of the research project under a grant from UN Environment through the Coordinating Body for the Seas of East Asia (COBSEA).
This grant is designed to support the development of an East Asian Seas Regional Node (RNSEA) of the GPML (Global Partnership on Marine Litter). It is based on a initial research project which resulted in a report: “A review of research on marine plastics in Southeast Asia: Who does what?” [link]
This position will involve:
- Support to the development of deliverables in the project with particular tasks to be defined for each by the team;
- Study of different research streams and proposals to combat pollution from marine plastics;
- Liaising with marine scientists and network design experts;
- Organisation for and participation to SEA of solutions in Bangkok, November 2019
This position is opened to 4th-year students and graduates with the following skills and experience:
- Preferred degrees: Bachelor or graduate degree including the study of international public law, public policy and public affairs, international relations, marine sciences and/or geography in the context of environmental sustainability;
- Rigourous research and analytical skills;
- Excellent communication skills / simple drafting style suitable for policy reports to be read by non-experts;
- Solid experience in policy analysis in the context of issues of sustainability, climate change and marine conservation;
- Ability to work independently and understand the needs of different stakeholder groups.
There is a possibility of extending this 3-months long position to one year or more for other projects in marine environmental law, policy and science. Send your CV and statement of interest to firstname.lastname@example.org, project lead.