17 research outputs found
Rethinking Outreach: Teaching the Process of Science through Modeling
How can we get high school students interested in science? Here is a program that matches students with researchers, with the purpose of building a physical model of the protein being investigated in the lab
Microbial Strain Prioritization Using Metabolomics Tools for the Discovery of Natural Products
Measurement of Estradiol in Human Serum by LC-MS/MS Using a Novel Estrogen-Specific Derivatization Reagent
A liquid chromatography–tandem
mass spectrometry (LC-MS/MS)
method is described that employs a novel derivatization reagent for
the measurement of serum estradiol (E2), with simultaneous analysis
of underivatized testosterone (T) and dihydrotestosterone (DHT). The
main advantage of the new derivatization reagent 1,2-dimethylimidazole-5-sulfonyl
chloride is its analyte-specific fragmentation that enables monitoring
of confirmatory mass transitions with high sensitivity. The reaction
mixture can be analyzed without additional purification steps using
a 9.5 min gradient run, and sensitive detection is achieved with a
triple quadrupole mass spectrometer using atmospheric pressure photoionization.
Method validation was performed with human serum samples, including
a comparison with a standard LC-MS/MS method using 120 samples from
a clinical study, and analysis of certified E2 serum reference materials
BCR-576, BCR-577, and BCR-578. The lower limits of quantification
for E2, T, and DHT were 0.5 pg/mL, 25 pg/mL, and 0.10 ng/mL, respectively,
from a 200-μL sample. Validation results indicated good accuracy
and agreement with established, conventional LC-MS/MS assays, demonstrating
suitability for analysis of samples containing E2 in the low pg/mL
range, such as serum from men, children, and postmenopausal women
Testosterone attenuates and the selective estrogen receptor modulator, raloxifene, potentiates amphetamine-induced locomotion in male rats
Although sex steroids are known to modulate brain dopamine, it is still unclear how testosterone modifies locomotor behaviour controlled, at least in part, by striatal dopamine in adolescent males. Our previous work suggests that increasing testosterone during adolescence may bias midbrain neurons to synthesise more dopamine. We hypothesised that baseline and amphetamine-induced locomotion would differ in adult males depending on testosterone exposure during adolescence. We hypothesised that concomitant stimulation of estrogen receptor signaling, through a selective estrogen receptor modulator (SERM), raloxifene, can counter testosterone effects on locomotion. Male Sprague-Dawley rats at postnatal day 45 were gonadectomised (G) or sham-operated (S) prior to the typical adolescent testosterone increase. Gonadectomised rats were either given testosterone replacement (T) or blank implants (B) for six weeks and sham-operated (i.e. intact or endogenous testosterone group) were given blank implants. Subgroups of sham-operated, gonadectomised and gonadectomised/testosterone-replaced rats were treated with raloxifene (R, 5. mg/kg) or vehicle (V), daily for the final four weeks. There were six groups (SBV, GBV, GTV, SBR, GBR, GTR). Saline and amphetamine-induced (1.25. mg/kg) locomotion in the open field was measured at PND85. Gonadectomy increased amphetamine-induced locomotion compared to rats with endogenous or with exogenous testosterone. Raloxifene increased amphetamine-induced locomotion in rats with either endogenous or exogenous testosterone. Amphetamine-induced locomotion was negatively correlated with testosterone and this relationship was abolished by raloxifene. Lack of testosterone during adolescence potentiates and testosterone exposure during adolescence attenuates amphetamine-induced locomotion. Treatment with raloxifene appears to potentiate amphetamine-induced locomotion and to have an opposite effect to that of testosterone in male rats
Data from: Eco-evolutionary feedbacks predict the time course of rapid life history evolution
Organisms can change their environment and, in so doing, change the selection they experience and how they evolve. Population density is one potential mediator of such interactions because high population densities can impact the ecosystem and reduce resource availability. At present, such interactions are best known from theory and laboratory experiments. Here we quantify the importance of such interactions in nature by transplanting guppies from a stream where they co-occur with predators into tributaries that previously lacked both guppies and predators. If guppies evolve solely because of the immediate reduction in mortality rate, the strength of selection and rate of evolution should be greatest at the outset then decline as the population adapts to its new environment. If indirect effects caused by the increase in guppy population density in the absence of predation prevail, then there should be a lag in guppy evolution because time is required for them to modify
their environment. The duration of this lag is predicted to be associated with the environmental modification caused by guppies. We observed a lag in life history evolution associated with increases in population density and altered ecology. How guppies evolved matched predictions derived from evolutionary theory that incorporates such density effects
MaleReproductiveSuccess
Reproductive success of males in the Lower LaLaja, based on the number of offspring in the pedigree assigned to each male
Pedigree for lab common garden
Pedigree of individuals included in the laboratory common garden experiment
Male Maturity Data - lab common gardens
Dependent values for the four common garden assays of age and size at maturity in male
MaleMatingSuccessData
Mating success of males derived from the pedigree for the Lower LaLaja stream