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.
Visit the NUS DBS webpage for details.
We (Dr. Chong Kwek Yan, A/P Hugh Tan, and A/P Darren Yeo) have a six-year funded project that seeks to develop an index of the biodiversity in urban areas. We are looking for one research staff, preferably a post-doctoral fellow (but see Requirements below), to join the team. The standard contract duration is one year but is renewable contingent upon good performance until the end of the project (estimated to be 30 June 2022).
- Develop an automated workflow to classify urban greenery cover and water bodies from freely available satellite imagery and spatial data sets.
- Analyze the relationships between the urban landscape and field data collected on bird, butterfly, odonate, and anuran communities.
- Lead the research team in project management, including working closely with the collaborating government agency, and drafting project progress reports and slides for and minutes of progress meetings.
- Lead the writing of scientific manuscripts for peer-reviewed journals.
- Mentor undergraduate research students contributing to the research project.
Preferably a PhD with demonstrated experience in landscape/spatial ecology and/or remote sensing projects; or a MSc in Applied Geographic Information Systems, or computer science or computer engineering with demonstrated experience in remote sensing, image classification, and spatial analytics. A BSc (Honours) with an excellent track record in related projects and publications and the relevant skill sets would also be considered.
More importantly, we are looking for following skills and experience:
- Proficiency in open-source scripting languages for image classification, spatial analysis, and statistical analyses, such as R or Python.
- Evidence of excellent writing (in English), including the ability to draft manuscripts for publication in peer-reviewed scientific journals.
- Good project management skills, including time management and attention to detail.
- Ability to work in and potentially lead a small team.
- Good verbal and scientific communication skills, including the ability to work with government agencies.
- Experience working with both freely available as well as commercially acquired high resolution satellite or drone imagery as well as spatial data sets, in particular related to the urban landscape.
- Experience using deep-learning techniques to map elements of urban greenery, such as individual trees, would be advantageous.
- Some experience with field surveys of urban wildlife.
Please apply online at this link. For any queries please contact Dr. Chong.
The Insect Diversity Lab at the Department of Biological Sciences, National University of Singapore, is in search of a full-time Research Assistant. We study global insect diversity with current focus on bees and related wasps of Southeast Asia. A key goal is to develop taxonomic infrastructure and to use this to advance research on insect urban ecology, behaviour, and conservation.
Core Responsibilities include:
- Process collected specimens (pinning, labelling, curating, and dissection for DNA).
- Organise and conduct DNA barcoding work for bees of Singapore and Southeast Asia.
- Specimen preparation, database entries, DNA extractions, PCR and data analyses.
- Data entry and management of specimen and bibliographic databases.
- Coordinate with collaborators within the NUS Department of Biological Sciences and overseas.
Additional Responsibilities may include, but are not limited to:
- Technical and report/scientific paper editing.
- Specimen imaging using an imaging system.
- Procuring equipment and consumables.
- Ensuring proper maintenance and/or replacement of existing equipment.
- Managing laboratory’s grants and budget.
- Acting as a liaison with various external agencies, e.g. NParks to obtain permits.
- Field sampling of bees/wasps using a sweep net.
- Prior experience with molecular taxonomy, especially DNA barcoding and molecular diagnostics.
- Prior experience in the field of entomology will help but can be picked up on the job.
- Written and verbal competency in the English language is a necessity.
- Familiarity with NGS barcoding techniques is desirable.
- Prior technical expertise or familiarity with software used in data management, analysis, and visualization is preferred.
- Additional abilities/experience in statistics is desirable.
- The candidate should be conscientious and adaptive, and enthusiastic about working with insects both alive and dead.
- The job requires attention to detail and the ability to maintain focus when working independently.
- This position is for 1 year, with potential for renewal.
- Applicants should be ready to start work in January 2020.
- Degree in Life Sciences or related field.
- Remuneration: SGD $3,000/month (dependent on qualifications and includes CPF contribution for Singaporeans/PR).
- Interested applicants should submit their CV, a short write-up about how this job may contribute to the applicant’s long term goals, and a sample of their academic writing.
- Please submit these to Dr John Ascher (email@example.com), Mr Tan Ming Kai (firstname.lastname@example.org), and Miss Ong Xin Rui (email@example.com) by 23 September 2019.
- Short-listed applicants will be notified for an interview by end-September 2019.
Assistant Professor John Stoskopf Ascher
Department of Biological Sciences
National University of Singapore
16 Science Drive 4, Singapore 117558
Camphora Pte Ltd is a collective that provides integrated flora, fauna and arboriculture baseline data to inform design intent and formulate solutions for ecological conservation
We are seeking to hire an enthusiastic and self-motivated individual who has a passion for botany and enjoys working in the outdoors.
You will mainly be assisting the Lead Botanist in (but not limited to):
- Planning and execution of flora surveys
- Integrate flora surveys with fauna and arboriculture surveys in baseline studies
- Report writing
- Attend and prepare for meetings
- Degree in Environmental Science, Botany, Zoology, Horticulture or related fields
- Passionate about plants, botany and horticulture
- Responsible, independent, and possess strong interpersonal skills
- Physically fit, and comfortable being outdoors and in the forest
- Training will be provided but familiarity with local flora will be an advantage. Fresh graduates are welcomed to apply.
Appointment will be on a 1-year contract basis and salary will commensurate with qualification and experience.
To apply, please send a cover letter and CV to Derek Yap at firstname.lastname@example.org.