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Record W4206786836 · doi:10.22215/etd/2021-14804

Investigating a Link Between Cold Stress and Bacterial Leak from the Gut of Locusta Migratoria

2021· dissertation· en· W4206786836 on OpenAlexaff
Mahmoud El-Saadi

Bibliographic record

Venuenot available
Typedissertation
Languageen
FieldImmunology and Microbiology
TopicInvertebrate Immune Response Mechanisms
Canadian institutionsCarleton University
Fundersnot available
KeywordsImmune systemBacteriaBiologyCold stressHomeostasisInsectGut floraLeakCell biologyZoologyMicrobiologyEcologyImmunologyBiochemistry

Abstract

fetched live from OpenAlex

Following prolonged low temperature exposure, chill-susceptible insects can incur chilling injuries that manifest as motor deficits and tissue damage. This tissue damage is thought to be driven by a loss of ion and water homeostasis, characterized by elevated potassium concentration in the hemolymph (hyperkalemia). The insect gut plays a major role in the maintenance of ion and water balance, and gut epithelial barrier function is compromised during chilling, which can contribute to the leak of water and solutes across the gut wall. The insect gut also houses an abundant bacterial population which can contribute to the host's cold tolerance. In recent years, however, a growing number of studies have reported increased activation of the insect immune system following a cold stress, suggesting that cold stress may cause bacterial infection. For my research, I hypothesized that prolonged cold stresses result in the leak of bacteria from the gut into the surrounding hemolymph as a possible explanation for the immune activation. With locusts as my model insect, I used an E. coli strain that expresses a fluorescent marker (GFPmut3) to track bacterial leak from the gut. After a period of feeding on wheat that was soaked in a concentrated solution of the bacteria, locusts were exposed to -2C for varying lengths of time before hemolymph was extracted and plated on agar media to facilitate bacterial colony growth. Surprisingly, I found no evidence of bacterial leak as no colonies were observed regardless of cold exposure length. My research strongly suggests that gut barrier integrity is well maintained even after severe cold stresses and is sufficient enough to prevent the leak of whole bacteria across the gut wall, which opens up other possible explanations as to why immune activation occurs following cold exposures in insects.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow), Insufficient payload (model declined to judge)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.027
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0010.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.013
GPT teacher head0.236
Teacher spread0.223 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

Study designBench or experimental
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations0
Published2021
Admission routes1
Has abstractyes

Explore more

Same topicInvertebrate Immune Response MechanismsFrench-language works237,207