Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
416
result(s) for
"Cole, Stephanie"
Sort by:
Ready...Set...Read! : the beginning reader's treasury
A collection of stories, poems, and non-fiction for beginning readers, by such authors as Dr. Seuss, Else Minarik, and Arnold Lobel.
Book
Electron-shuttling antibiotics structure bacterial communities by modulating cellular levels of c-di-GMP
Diverse organisms secrete redox-active antibiotics, which can be used as extracellular electron shuttles by resistant microbes. Shuttle-mediated metabolism can support survival when substrates are available not locally but rather at a distance. Such conditions arise in multicellular communities, where the formation of chemical gradients leads to resource limitation for cells at depth. In the pathogenic bacterium Pseudomonas aeruginosa PA14, antibiotics called phenazines act as oxidants to balance the intracellular redox state of cells in anoxic biofilm subzones. PA14 colony biofilms show a profound morphogenic response to phenazines resulting from electron acceptor-dependent inhibition of ECM production. This effect is reminiscent of the developmental responses of some eukaryotic systems to redox control, but for bacterial systems its mechanistic basis has not been well defined. Here, we identify the regulatory protein RmcA and show that it links redox conditions to PA14 colony morphogenesis by modulating levels of bis-(3′,5′)-cyclic-dimeric-guanosine (c-di-GMP), a second messenger that stimulates matrix production, in response to phenazine availability. RmcA contains four Per-Arnt-Sim (PAS) domains and domains with the potential to catalyze the synthesis and degradation of c-di-GMP. Our results suggest that phenazine production modulates RmcA activity such that the protein degrades c-di-GMP and thereby inhibits matrix production during oxidizing conditions. RmcA thus forms a mechanistic link between cellular redox sensing and community morphogenesis analogous to the functions performed by PAS-domain–containing regulatory proteins found in complex eukaryotes.
Journal Article
Hot diggity dogs
When a new hot dog stand opens in town, dog-lovers Kate and Lucie rush to try it out, and the food is great, but the owners' dachshunds, Ketchup and Mustard, soon disappear. It's up to the girls to save the day, while evading boys and preparing for the Bark-in-the-Park dog competition.
Book
Diversity in receptor-like kinase genes is a major determinant of quantitative resistance to Fusarium oxysporum f.sp. matthioli
Resistance to wilt fungus Fusarium oxysporum f.sp. matthioli (FOM) is a polygenic trait in Arabidopsis thaliana. RFO3 is one of six quantitative trait loci accounting for the complete resistance of accession Columbia-0 (Col-0) and susceptibility of accession Taynuilt-0 (Ty-0).
We find that Col-0 and Ty-0 alleles of RFO3 are representative of two common variants in wild Arabidopsis accessions, that resistance and susceptibility to FOM are ancestral features of the two variants and that resistance from RFO3 is unrivalled by other genes in a genome-wide survey of diversity in accessions. A single receptor-like kinase (RLK) gene in Col-0 is responsible for the resistance of RFO3, although the susceptible Ty-0 allele codes for two RLK homologs.
Expression of RFO3 is highest in vascular tissue, which F. oxysporum infects, and rootexpressed RFO3 restricts FOM infection of the vascular system. RFO3 confers specific resistance to FOM and provides no resistance to two other crucifer-infecting F. oxysporum pathogens.
RFO3's identity, expression and specificity suggest that RFO3 represents diversity in pattern-recognition receptor (PRR) genes. The characteristics of RFO3 and the previously published RFO1 suggest that diversity in RLK PRRs is a major determinant of quantitative resistance in wild plant populations.
Journal Article
No dogs allowed
Best friends and dog lovers Kate and Lucie live in apartments where dogs are not allowed, but a pair of unusual necklaces they find in a thrift store allow them to become dogs whenever they wish.
Book
Host suppression of quorum sensing during catheter-associated urinary tract infections
Chronic bacterial infections on medical devices, including catheter-associated urinary tract infections (CAUTI), are associated with bacterial biofilm communities that are refractory to antibiotic therapy and resistant to host immunity. Previously, we have shown that
Pseudomonas aeruginosa
can cause CAUTI by forming a device-associated biofilm that is independent of known biofilm exopolysaccharides. Here, we show by RNA-seq that host urine alters the transcriptome of
P. aeruginosa
by suppressing quorum sensing regulated genes.
P. aeruginosa
produces acyl homoserine lactones (AHLs) in the presence of urea, but cannot perceive AHLs. Repression of quorum sensing by urine implies that quorum sensing should be dispensable during infection of the urinary tract. Indeed, mutants defective in quorum sensing are able to colonize similarly to wild-type in a murine model of CAUTI. Quorum sensing-regulated processes in clinical isolates are also inhibited by urea. These data show that urea in urine is a natural anti-quorum sensing mechanism in mammals.
Pseudomonas aeruginosa
can cause chronic infections on medical devices by forming biofilms, a process regulated by quorum sensing (QS). Here, the authors show that
P. aeruginosa
is unable to perceive QS signals in the presence of either host urine or urea, and clinical isolates are often defective in QS.
Journal Article
Teacher's pets
\"The girls are dismayed when their teacher is out sick and they have a substitute. Mr. Z makes goofy jokes and can't keep the class under control. Worst of all, he doesn't say anything when mean Darlene makes fun of Kate and Lucie. Luckily, once the girls turn into dogs, Kate and Lucie learn they can save the day--and even make a new friend\"-- Provided by publisher.
Book
Worldwide population variation in pelvic sexual dimorphism: A validation and recalibration of the Klales et al. method
Sex estimation is an integral aspect of biological anthropology. Correctly estimating sex is the first step to many subsequent analyses, such as estimating living stature or age-at-death. Klales et al. (2012) [6] provided a revised version of the Phenice (1969) [3] method that expanded the original three traits (ventral arc, subpubic concavity/contour, and medial aspect of the ischio-pubic ramus) into five character states to capture varying degrees of expression within each trait. The Klales et al. (2012) [6] method also provided associated probabilities with each sex classification, which is of particular importance in forensic anthropology. However, the external validity of this method must be tested prior to applying the method to different populations from which the method was developed. A total of 1915 innominates from four diverse geographic populations: (1) U.S. Blacks and Whites; (2) South African Blacks and Whites; (3) Thai; and (4) unidentified Hispanic border crossers were scored in accordance with Klales et al. (2012) [6]. Trait scores for each innominate were entered into the equation provided by Klales et al. (2012) [6] for external validation. Additionally, recalibration equations were calculated with logistic regression for each population and for a pooled global sample. Validation accuracies ranged from 87.5% to 95.6% and recalibration equation accuracies ranged from 89.6% to 98% total correct. Pooling all samples and using Klales’ et al. (2012) [6] equations achieved an overall validation accuracy of 93.5%. The global recalibration model achieved 95.9% classification accuracy and can be employed in diverse worldwide populations for accurate sex estimation without the need for population specific equations.
Journal Article
Postoperative tonsil/adenoidectomy bleeding management in patients with diagnosed bleeding disorders
Objective Tonsil/adenoidectomy (T/A) is a commonly performed procedure with an average post‐tonsillectomy bleed (PTB) rate between 3 and 5%. Patients with bleeding disorders (BDs) are believed to have an increased risk of PTB. We hypothesize that our medical management of BD patients using a combination of DDAVP/antifibrinolytic agents has a similar PTB rate to control patients. This study suggests a standardized protocol for patients with BDs to avoid PTB. Methods A retrospective cohort study was completed for patients with BD who underwent tonsillectomy or T/A at Promedica Toledo or Flower Hospital between 2013 and 2020. Exclusion criteria included incomplete records, diagnosis of BD after surgery, and inability to find age and sex matched control. We defined the control group as patients who underwent T/A without BD. The following variables were collected: age, sex, medical history, BD severity, medications, type of surgery, indication for surgery, estimated blood loss (EBL), pre/postoperative medications, PTB status, and post‐PTB intervention. Results A total of 164 patient charts were reviewed. There were 82 patients in both cohorts. The BDs represented were platelet function disorder (80.5%), von Willebrand disease (14.6%), and others such as Factor VII and IX deficiency (4.9%). Of the BD patients included, 13.4% had severe disease. There was no significant difference between the age, sex, EBL, and PTB rates. Of the 8 BD patients with PTB, 62% bled 9‐10 days postoperatively and none had severe disease. Conclusion Our protocol to prevent PTB in patients with BDs produced similar bleed rates to control patients in this study. Further studies are required to assess postoperative length of antifibrinolytic treatment in BD patients. Level of Evidence III.
Journal Article
Variability in cell-free expression reactions can impact qualitative genetic circuit characterization
Abstract
Cell-free expression systems provide a suite of tools that are used in applications from sensing to biomanufacturing. One of these applications is genetic circuit prototyping, where the lack of cloning is required and a high degree of control over reaction components and conditions enables rapid testing of design candidates. Many studies have shown utility in the approach for characterizing genetic regulation elements, simple genetic circuit motifs, protein variants or metabolic pathways. However, variability in cell-free expression systems is a known challenge, whether between individuals, laboratories, instruments, or batches of materials. While the issue of variability has begun to be quantified and explored, little effort has been put into understanding the implications of this variability. For genetic circuit prototyping, it is unclear when and how significantly variability in reaction activity will impact qualitative assessments of genetic components, e.g. relative activity between promoters. Here, we explore this question by assessing DNA titrations of seven genetic circuits of increasing complexity using reaction conditions that ostensibly follow the same protocol but vary by person, instrument and material batch. Although the raw activities vary widely between the conditions, by normalizing within each circuit across conditions, reasonably consistent qualitative performance emerges for the simpler circuits. For the most complex case involving expression of three proteins, we observe a departure from this qualitative consistency, offering a provisional cautionary line where normal variability may disrupt reliable reuse of prototyping results. Our results also suggest that a previously described closed loop controller circuit may help to mitigate such variability, encouraging further work to design systems that are robust to variability.
Graphical Abstract
Journal Article