Erin McParland
Ph.D. Candidate, MBBO Graduate Program (PI: Dr. Naomi Levine)
The dynamic regulation of DMSP production by marine phytoplankton
Wednesday, May 8, 2019
10 AM
AHF 153 (Torrey Webb Room)
Abstract: Dimethylsulfoniopropionate (DMSP) is a labile sulfur and carbon metabolite that significantly contributes to both the cycling of marine dissolved organic carbon and the balance of Earth’s albedo. DMSP is produced by the majority of eukaryotic marine phytoplankton and by many prokaryotes, but despite decades of research, the cellular mechanism and environmental drivers of DMSP production remain unknown. My thesis confirms that the cellular mechanism of DMSP is differentiated by the cellular concentrations of DMSP in different producers, where high DMSP producers (e.g. dinoflagellates and haptophytes) constitutively produce DMSP and low DMSP producers (e.g. cyanobacteria and diatoms) actively regulate DMSP production in response to environmental stress. However, with natural community experiments and global model predictions, my thesis demonstrates that variability of in situ DMSP production is driven by the biomass of high producers. My thesis highlights the potential for predicting in situ DMSP concentrations with a high DMSP producer marker gene and demonstrates the importance of accurately capturing the sub-dominant community for prediction of DMSP, or other similar metabolites produced by a small fraction of the marine microbial community.
Showing posts with label defense. Show all posts
Showing posts with label defense. Show all posts
Monday, April 29, 2019
MBBO Ph.D. Dissertation Defense | Pingping Qu
Pingping Qu
Ph.D. Candidate, MBBO Graduate Program (PI: Dr. David Hutchins)
Thermal Acclimation and Adaptation of Key Phytoplankton Groups and Interactions with Other Global Change Variables
Wednesday, May 1, 2019
11 AM
AHF 153 (Torrey Webb Room)
Abstract: Marine phytoplankton play critical roles in global primary productivity, carbon export and biogeochemistry. The relationships between environmental forcing and key phytoplankton groups in marine ecosystems need more attention, especially under global change scenarios. Among many other environmental changes, phytoplankton communities in the euphotic zone are anticipated to be most sensitive to concurrent ocean acidification, warming, more thermal variability and reduced nutrient supplies.
Marine diatoms play critical roles in global primary productivity, carbon export and the food web. Marine diazotrophic cyanobacteria are equally important as a source of new nitrogen through nitrogen fixation. In order to better understand the possible responses of marine diatoms and diazotrophs to a changing ocean environment, my studies focused on the synergistic effects of multiple climate change variables on an important diatom, as well as the responses of two keystone diazotrophs to thermal variability and to long-term selection by warming.
In my first chapter, the physiological responses of the widespread centric diatom Coscinodiscus sp. to interactions between three climate-change variables (elevated CO2, warming, and nitrate availability) were investigated to better understand the interactions of multiple global changes on large, carbon-exporting diatoms. The second one examined how short-term thermal variability affects the growth and physiology of the diazotrophic cyanobacterium Trichodesmium erythraeum GBRTRLI101, as well as the interaction between temperature variation and phosphate availability. The third chapter tested the physiological responses and compared and contrasted acclimation and adaptation of Trichodesmium erythraeum IMS101 and Crocosphaera WH0005 under long-term experimental selection at different temperatures, exploring possible ecological and biogeochemical implications of ways that these two representative diazotrophic cyanobacteria may cope with future warmer conditions.
Ph.D. Candidate, MBBO Graduate Program (PI: Dr. David Hutchins)
Thermal Acclimation and Adaptation of Key Phytoplankton Groups and Interactions with Other Global Change Variables
Wednesday, May 1, 2019
11 AM
AHF 153 (Torrey Webb Room)
Abstract: Marine phytoplankton play critical roles in global primary productivity, carbon export and biogeochemistry. The relationships between environmental forcing and key phytoplankton groups in marine ecosystems need more attention, especially under global change scenarios. Among many other environmental changes, phytoplankton communities in the euphotic zone are anticipated to be most sensitive to concurrent ocean acidification, warming, more thermal variability and reduced nutrient supplies.
Marine diatoms play critical roles in global primary productivity, carbon export and the food web. Marine diazotrophic cyanobacteria are equally important as a source of new nitrogen through nitrogen fixation. In order to better understand the possible responses of marine diatoms and diazotrophs to a changing ocean environment, my studies focused on the synergistic effects of multiple climate change variables on an important diatom, as well as the responses of two keystone diazotrophs to thermal variability and to long-term selection by warming.
In my first chapter, the physiological responses of the widespread centric diatom Coscinodiscus sp. to interactions between three climate-change variables (elevated CO2, warming, and nitrate availability) were investigated to better understand the interactions of multiple global changes on large, carbon-exporting diatoms. The second one examined how short-term thermal variability affects the growth and physiology of the diazotrophic cyanobacterium Trichodesmium erythraeum GBRTRLI101, as well as the interaction between temperature variation and phosphate availability. The third chapter tested the physiological responses and compared and contrasted acclimation and adaptation of Trichodesmium erythraeum IMS101 and Crocosphaera WH0005 under long-term experimental selection at different temperatures, exploring possible ecological and biogeochemical implications of ways that these two representative diazotrophic cyanobacteria may cope with future warmer conditions.
Monday, February 25, 2019
IEB Ph.D. Defense | Nicole Adams
Nicole Adams
Ph.D. Candidate, Integrative & Evolutionary Biology Graduate Program
Google Scholar Profile
Genetic diversity and its effect on the scat microbiome in the threatened insular canid, Urocyon littoralis
Tuesday, March 5
1 PM
RRI 121
Abstract: Loss of genetic diversity in wild populations can have profound effects on the ability of a population to respond to a changing environment. Small populations can have low genetic variation due to inbreeding and strong drift, which may be exacerbated by further declines in population size. The Channel Island fox, Urocyon littoralis, was delisted/down-listed from the federal endangered species list in 2016 after successful conservation efforts brought them back from a 90-99% population decline in the 1990s. While their demographic recovery has been dramatic, much less is known about their genetic recovery. Therefore, we looked at the “natural” experiment of the Channel Island fox population declines, which varied in bottleneck presence, size, cause, and recovery across multiple islands. To assess their recovery, we conducted the first direct genetic comparison at the population level of pre- and post-bottleneck samples. In order to understand functional consequences associated with the loss of genetic diversity, we evaluated the relationship between island fox genetics and the bacterial community after characterizing the scat bacterial community using 16S amplicon sequencing.
PI: Drs. Suzanne Edmands and Xiaoming Wang
Ph.D. Candidate, Integrative & Evolutionary Biology Graduate Program
Google Scholar Profile
Genetic diversity and its effect on the scat microbiome in the threatened insular canid, Urocyon littoralis
Tuesday, March 5
1 PM
RRI 121
Abstract: Loss of genetic diversity in wild populations can have profound effects on the ability of a population to respond to a changing environment. Small populations can have low genetic variation due to inbreeding and strong drift, which may be exacerbated by further declines in population size. The Channel Island fox, Urocyon littoralis, was delisted/down-listed from the federal endangered species list in 2016 after successful conservation efforts brought them back from a 90-99% population decline in the 1990s. While their demographic recovery has been dramatic, much less is known about their genetic recovery. Therefore, we looked at the “natural” experiment of the Channel Island fox population declines, which varied in bottleneck presence, size, cause, and recovery across multiple islands. To assess their recovery, we conducted the first direct genetic comparison at the population level of pre- and post-bottleneck samples. In order to understand functional consequences associated with the loss of genetic diversity, we evaluated the relationship between island fox genetics and the bacterial community after characterizing the scat bacterial community using 16S amplicon sequencing.
PI: Drs. Suzanne Edmands and Xiaoming Wang
Monday, October 22, 2018
Thesis Center Office Hours + FAQ for Students
Sam Mantell of the Graduate School will be holding Thesis Center Office Hours. If you will be submitting a thesis/dissertation manuscript this term and need one-on-one assistance with Thesis Center, please schedule an appointment to meet with him.
Office Hours will be held on UPC, in STU 301, and on HSC, in CHP 219, between 10 /18 and 10/24. Office Hours appointments can be scheduled on the Graduate School website, in the Graduate Events page.
Attached, you will find Thesis Center FAQ for Students.
Office Hours will be held on UPC, in STU 301, and on HSC, in CHP 219, between 10 /18 and 10/24. Office Hours appointments can be scheduled on the Graduate School website, in the Graduate Events page.
Attached, you will find Thesis Center FAQ for Students.
Thesis Center FAQ for Students by uscbiscgrad on Scribd
Tuesday, November 15, 2016
Ph.D. Defense | Comparative Ecology and Physiology of Critically Endangered Madagascar Tortoises
Andrea Currylow
Ph.D. Candidate
Integrative & Evolutionary Biology Graduate Program
Tuesday, November 29
1-2 PM
RRI 321
Abstract: For ectotherms, physiology and behavior are critically tied to environmental conditions. Feeding, metabolism, reproduction, and even movement are strongly influenced by temperature, cover availability, and resource quality. The underlying mechanisms of these interactions are, however, poorly understood. The use of seasonal baseline hormone concentrations and data on ranging behavior can be used to determining the potential reproductive output in both wild and captive populations. Using three closely related, critically endangered Malagasy tortoise species as models, I assessed the tempo and mode of reproductive potential, activity, and health (stress and body condition) by measuring circulating stress and sex steroid hormones in conjunction with environmental, physical, activity, and behavioral data.
Ph.D. Candidate
Integrative & Evolutionary Biology Graduate Program
Tuesday, November 29
1-2 PM
RRI 321
Abstract: For ectotherms, physiology and behavior are critically tied to environmental conditions. Feeding, metabolism, reproduction, and even movement are strongly influenced by temperature, cover availability, and resource quality. The underlying mechanisms of these interactions are, however, poorly understood. The use of seasonal baseline hormone concentrations and data on ranging behavior can be used to determining the potential reproductive output in both wild and captive populations. Using three closely related, critically endangered Malagasy tortoise species as models, I assessed the tempo and mode of reproductive potential, activity, and health (stress and body condition) by measuring circulating stress and sex steroid hormones in conjunction with environmental, physical, activity, and behavioral data.
Thursday, September 24, 2015
Thesis and Dissertation Submission Info Sessions
As the thesis and dissertation submission deadline
approaches for the Fall 2015 semester, the Graduate School will host
information sessions detailing the thesis submission process on two Wednesdays
in October. The University Park Campus sessions will take place on October
7th, in THH 301 at 12:00 pm and THH 102 at 5:00
pm. The Health Sciences Campus session will take place on October
14th, in MCH 156 at 12:00
pm.
Topics will include important information for both students
and advisors, such as:
· Thesis
Center navigation
· submission
deadlines
· required
documentation
There will be an opportunity for questions following the
presentation. Please mark your calendars. Hope to see you there!
Wednesday, September 17, 2014
Wednesday, February 6, 2013
Dissertation/Thesis Submission Forums
Two forums focusing on thesis and dissertation formatting and
submission process will be held later this month, one on the Health Sciences
campus and the other on the University Park campus. Please distribute the
following information to graduate students in your program who are preparing to
submit their theses and dissertations, especially to those who intend to file by
the Spring conferral deadlines.
Health Sciences Campus
Thursday, February 21st, 2013
2:30 – 3:30pm
NTT7409
University Park Campus
Friday, February 22nd, 2013
1:15 – 2:15pm
KAP 146
Please ask students to review the revised process and
requirements on the Graduate School Website, and to ‘like’ us on Facebook and
follow us on Twitter for important information and updates.
Thanks in advance for your assistance,
Frances
Frances M. Fitzgerald
Student Services Coordinator
The Graduate School
GFS 315 mc 1695
(213) 740-9045
Friday, June 18, 2010
Defense Instructions
Thinking about defending soon? These are your defense instructions. Please make sure that you have completed ALL of the following steps:
1) Download the dissertation submission packet and format and presentation guidelines from the Graduate School website: http://www.usc.edu/schools/GraduateSchool/current_thesis_dissert.html.
2) Complete your online dissertation profile on the Graduate School website: http://www.usc.edu/schools/GraduateSchool/WebThesis
3) Defend your dissertation. Take the following forms with you to your defense:
a) "Approval to Submit Defended and Final Copy of Doctoral Work" form
b) Signature Page
4) The "Approval to Submit" form should be signed by the committee after all changes have been made to your dissertation (if any). The date on this form stops the tuition clock and starts the submission clock. You have three months from this date to submit your dissertation without a late fee.
5) Pay your binding fee ($115) and get a receipt.
6) Bring ALL ORIGINAL forms listed on the "Documentation Review Form" to Linda Bazilian when you are ready to submit. She will make the necessary copies.
7) Linda will sign off on the "Verification" form and the "Documentation Review Form". Do NOT have either form signed by your dissertation advisor. You will then be ready to submit.
Best of luck to you all!
1) Download the dissertation submission packet and format and presentation guidelines from the Graduate School website: http://www.usc.edu/schools/GraduateSchool/current_thesis_dissert.html.
2) Complete your online dissertation profile on the Graduate School website: http://www.usc.edu/schools/GraduateSchool/WebThesis
3) Defend your dissertation. Take the following forms with you to your defense:
a) "Approval to Submit Defended and Final Copy of Doctoral Work" form
b) Signature Page
4) The "Approval to Submit" form should be signed by the committee after all changes have been made to your dissertation (if any). The date on this form stops the tuition clock and starts the submission clock. You have three months from this date to submit your dissertation without a late fee.
5) Pay your binding fee ($115) and get a receipt.
6) Bring ALL ORIGINAL forms listed on the "Documentation Review Form" to Linda Bazilian when you are ready to submit. She will make the necessary copies.
7) Linda will sign off on the "Verification" form and the "Documentation Review Form". Do NOT have either form signed by your dissertation advisor. You will then be ready to submit.
Best of luck to you all!
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