Sensitivity of Lake Sturgeon population dynamics and genetics to demographic parameters [Powerpoint Slide]

Lake sturgeon Acipenser fulvescens restoration is a priority throughout the Great Lakes basin, where sturgeon have been reduced to less than 1% of historic levels due to habitat degradation, overharvest, and fragmentation of spawning populations. The population parameters most important to long-term lake sturgeon persistence are unknown

Case Report: Recurrent Staphylococcal Scalded Skin Syndrome in Healthy Term Neonate Despite Full Course of Antibiotic Therapy

Background Staphylococcal scalded skin syndrome (SSSS) describes a blistering skin infection caused by the exfoliative toxin in the bacterium Staphylococcus aureus. It more commonly affects the infant population and is characterized by large blistering bullae that rupture upon application of pressure. Case description We describe a case of recurrent SSSS in a healthy term neonate who initially presented with a perioral rash on day of life (DOL) 11 that quickly became vesicular with new lesions on the sternum and extremities. The patient’s rash began to resolve upon administration of culture-specific IV antibiotics. She was appropriately treated with a 14-day course and was discharged home. The patient returned on DOL 35 with a perioral rash and generalized reddening of the skin. She was admitted and placed empirically on nafcillin, clindamycin, and vancomycin for concerning recurrence of SSSS. At this time, consults were placed to Dermatology, as well as Allergy & Immunology for possible Epidermolysis Bullosa and immune deficiency. Skin biopsy revealed development of recurrent SSSS. Patient finished another 14-day course of IV antibiotics and was discharged home with resolution of the rash. Conclusion This report discusses a case of recurrent SSSS in a term neonate who received two full courses of antibiotics and has since fully recovered. Key words: Staphylococcal scalded skin syndrome, epidermolysis bullosa, disease recurrenc

Postbaccalaureate STEM Students’ Perceptions of their Training: Exploring the Intersection of Gender and Nativity

The number of international students in graduate school within STEM fields at US institutions has risen dramatically over the last few decades, whereas the numbers of US women attending graduate school in STEM fields has largely stagnated. These trends suggest the importance of intersectionality to understanding individuals’ pursuit of STEM careers. Here we examined doctoral (N = 270) and postdoctoral (N = 27) students\u27 satisfaction with their graduate training at a large, research focused institution in the US as a function of the intersection of participants’ gender and nativity. Participants completed measures of occupational values, perceived fit of their values with STEM research careers, perceptions of discrimination, mentor support, and satisfaction with their graduate training. Results indicated that both international and US-born women both valued family flexibility more than did international and US-born men. Importantly, international, but not US-born, women viewed careers in STEM research as affording, or providing a means of fulfilling, their values. Furthermore, US women were more likely than international women to perceive their gender as the target of discrimination. Stronger belief that research careers do not provide a means for fulfilling one’s values and greater perceptions of gender discrimination were associated with lower ratings of satisfaction with graduate training among women but not men

Tat RNA silencing suppressor activity contributes to perturbation of lymphocyte miRNA by HIV-1

<p>Abstract</p> <p>Background</p> <p>MicroRNA (miRNA)-mediated RNA silencing is integral to virtually every cellular process including cell cycle progression and response to virus infection. The interplay between RNA silencing and HIV-1 is multifaceted, and accumulating evidence posits a strike-counterstrike interface that alters the cellular environment to favor virus replication. For instance, miRNA-mediated RNA silencing of HIV-1 translation is antagonized by HIV-1 Tat RNA silencing suppressor activity. The activity of HIV-1 accessory proteins Vpr/Vif delays cell cycle progression, which is a process prominently modulated by miRNA. The expression profile of cellular miRNA is altered by HIV-1 infection in both cultured cells and clinical samples. The open question stands of what, if any, is the contribution of Tat RNA silencing suppressor activity or Vpr/Vif activity to the perturbation of cellular miRNA by HIV-1.</p> <p>Results</p> <p>Herein, we compared the perturbation of miRNA expression profiles of lymphocytes infected with HIV-1^NL4-3or derivative strains that are deficient in Tat RNA silencing suppressor activity (Tat K51A substitution) or ablated of the vpr/vif open reading frames. Microarrays recapitulated the perturbation of the cellular miRNA profile by HIV-1 infection. The miRNA expression trends overlapped ~50% with published microarray results on clinical samples from HIV-1 infected patients. Moreover, the number of miRNA perturbed by HIV-1 was largely similar despite ablation of Tat RSS activity and Vpr/Vif; however, the Tat RSS mutation lessened HIV-1 downregulation of twenty-two miRNAs.</p> <p>Conclusions</p> <p>Our study identified miRNA expression changes attributable to Tat RSS activity in HIV-1^NL4-3. The results accomplish a necessary step in the process to understand the interface of HIV-1 with host RNA silencing activity. The overlap in miRNA expression trends observed between HIV-1 infected CEMx174 lymphocytes and primary cells supports the utility of cultured lymphocytes as a tractable model to investigate interplay between HIV-1 and host RNA silencing. The subset of miRNA determined to be perturbed by Tat RSS in HIV-1 infection provides a focal point to define the gene networks that shape the cellular environment for HIV-1 replication.</p

Development of an Oral Form of Azacytidine: 2′3′5′Triacetyl-5-Azacytidine

Myelodysplastic syndromes (MDSs) represent a group of incurable stem-cell malignancies which are predominantly treated by supportive care. Epigenetic silencing through promoter methylation of a number of genes is present in poor-risk subtypes of MDS and often predicts transformation to acute myelogenous leukemia (AML). Azacitidine and decitabine, two FDA-approved DNA methyltransferase (DNMT) inhibitors, are able to improve overall response although their oral bioavailability complicates their clinical use. This study evaluated 2′, 3′, 5′-triacetyl-5-azacitidine (TAC) as a potential prodrug for azacitidine. The prodrug demonstrated significant pharmacokinetic improvements in bioavailability, solubility, and stability over the parent compound. In vivo analyses indicated a lack of general toxicity coupled with significantly improved survival. Pharmacodynamic analyses confirmed its ability to suppress global methylation in vivo. These data indicate that esterified nucleoside derivatives may be effective prodrugs for azacitidine and encourages further investigation of TAC into its metabolism, activity, and possible clinical evaluation

Probing the Evolution of the Galaxy Interaction/Merger Rate Using Collisional Ring Galaxies

We present the results from our program to determine the evolution of the galaxy interaction/merger rate with redshift using the unique star-forming characteristics of collisional ring galaxies. We have identified 25 distant collisional ring galaxy candidates (CRGCs) in a total of 162 deep Hubble Space Telescope Wide Field/Planetary Camera-2 images obtained from the HST Archives. Based on measured and estimated redshifts, these 25 CRGCs all lie in the redshift interval of 0.1 < z < 1. Using the local collisional ring galaxy volume density and the new ``standard'' cosmology, we find that in order to account for the number of identified CRGCs in our surveyed fields, the galaxy interaction/merger rate, parameterized as (1 + z)^m, must increase steeply with redshift.We determine a minimum value of m = 5.2 $\pm$ 0.7, though m could be as high as 7 or 8. We can rule out a non-evolving (m = 0) and weakly evolving (m = 1-2) galaxy interaction/merger rate at greater than the 4 sigma level of confidence.Comment: Accepted in the Astrophysical Journal (11 pages, 4 figures). Higher resolution version of the figures is available at http://www.astro.cornell.edu/~vassilis/papers