ALBERT

Description: Advances in high-throughput characterization of protein networks in vivo have resulted in large databases of unexplored protein interactions that occur during normal cell function. Their further characterization requires quantitative experimental strategies that are easy to implement in laboratories without specialized equipment. We have overcome many of the previous limitations to thermodynamic quantification of protein interactions, by developing a series of in-solution fluorescence-based strategies. These methods have high sensitivity, a broad dynamic range, and can be performed in a high-throughput manner. In three case studies we demonstrate how fluorescence (de)quenching and fluorescence resonance energy transfer can be used to quantitatively probe various high-affinity protein–DNA and protein–protein interactions. We applied these methods to describe the preference of linker histone H1 for nucleosomes over DNA, the ionic dependence of the DNA repair enzyme PARP1 in DNA binding, and the interaction between the histone chaperone Nap1 and the histone H2A–H2B heterodimer.

Description: Radiolabeled diacetylbis(4-methylthiosemicarbazonato)copperII [CuII(atsm)] is an effective positron-emission tomography imaging agent for myocardial ischemia, hypoxic tumors, and brain disorders with regionalized oxidative stress, such as mitochondrial myopathy, encephalopathy, and lactic acidosis with stroke-like episodes (MELAS) and Parkinson’s disease. An excessively elevated reductive state is common to these conditions and has been proposed as an important mechanism affecting cellular retention of Cu from CuII(atsm). However, data from whole-cell models to demonstrate this mechanism have not yet been provided. The present study used a unique cell culture model, mitochondrial xenocybrids, to provide whole-cell mechanistic data on cellular retention of Cu from CuII(atsm). Genetic incompatibility between nuclear and mitochondrial encoded subunits of the mitochondrial electron transport chain (ETC) in xenocybrid cells compromises normal function of the ETC. As a consequence of this impairment to the ETC we show xenocybrid cells upregulate glycolytic ATP production and accumulate NADH. Compared to control cells the xenocybrid cells retained more Cu after being treated with CuII(atsm). By transfecting the cells with a metal-responsive element reporter construct the increase in Cu retention was shown to involve a CuII(atsm)-induced increase in intracellular bioavailable Cu specifically within the xenocybrid cells. Parallel experiments using cells grown under hypoxic conditions confirmed that a compromised ETC and elevated NADH levels contribute to increased cellular retention of Cu from CuII(atsm). Using these cell culture models our data demonstrate that compromised ETC function, due to the absence of O2 as the terminal electron acceptor or dysfunction of individual components of the ETC, is an important determinant in driving the intracellular dissociation of CuII(atsm) that increases cellular retention of the Cu.

Description: Simulations of an elevated mesoscale convective system (MCS) observed over southern England during the Convective Storm Initiation Project (CSIP) provide the first detailed modelling study of a case of elevated convection occurring in the UK. The study shows that many factors can influence the maintenance of elevated deep convection, from large-scale flow through to surface heating processes and diabatic cooling within the convective system. It is also shown that interactions and feedback mechanisms between a stable layer and the storm can act to maintain deep convection. The simulation successfully reproduced an elevated MCS above a low-level stable undercurrent, with a wave in the undercurrent linked to a rear-inflow jet (RIJ). Convection was fed from an elevated (840 hPa) source layer with CAPE of about 350 J kg − 1 . The undercurrent in the simulation was approximately 1 km deep, about half that observed. Unlike the observed MCS, a transition from elevated to surface-based convection occurred in the simulation due to the combined effects of a pre-existing large-scale θ e gradient, advection and surface heating causing the system to encounter increasingly unstable low-level air and a shallower stable layer that was more susceptible to penetration by downdraughts. The transition to surface-based convection was accompanied by the development of cold-pool outflow and an increase in system velocity from about 6 to 10 m s − 1 . Diabatic cooling from microphysical processes in the simulation enhanced the undercurrent and strengthened the RIJ. This strengthened the wave in the undercurrent and led to more extensive convection. The existence of a positive feedback process between the convection, RIJ and stable layer is discussed. Uncertainty in the synoptic scale generating errors in the undercurrent is shown to be a major source of error for convective-scale forecasts.

Description: The first results from coordinated experiments between the Radio Receiver Instrument (RRI) on the Enhanced Polar Outflow Probe (e-POP) and the Super Dual Auroral Radar Network (SuperDARN) Saskatoon High Frequency (HF) radar are examined for a conjunction on July 8, 2014. e-POP, a payload on the CAScade, Smallsat and IOnospheric Polar Explorer (CASSIOPE) spacecraft, was located at 380 km altitude, approximately 10 ∘ north (geographic) and 2 ∘ west of Saskatoon, Canada, moving in a southeast direction. We use a matched filter technique to extract individual received SuperDARN pulses from the RRI data stream. The pulses show characteristics of propagation through the F-region ionosphere: they are heavily they show significant pulse-to-pulse variability in magnitude, and there is clear evidence that they experienced multipath propagation. We calculate the polarization parameters of the pulses and use them to identify magnetoionic phenomena such as mode-splitting and single-mode fading. These first RRI results provide compelling insight into HF radio wave propagation, and show RRI's potential to significantly advance radio science.

Description: IJERPH, Vol. 15, Pages 934: Teens Implementing a Childhood Obesity Prevention Program in the Community: Feasibility and Perceptions of a Partnership with HSTA and iCook 4-H International Journal of Environmental Research and Public Health doi: 10.3390/ijerph15050934 Authors: Rebecca L. Hagedorn Jade A. White Lisa Franzen-Castle Sarah E. Colby Kendra K. Kattelmann Adrienne A. White Melissa D. Olfert High school student researchers and teen leaders from the Health Science Technology Academy (HSTA), under the supervision of HSTA teachers, led a childhood obesity prevention (COP) program (iCook 4-H). The objective was to evaluate the feasibility and perceptions of having teen leaders implement a COP program for dyads of youth (9–10 years old) and their primary adult food preparer. Behavior change and perceptions were assessed through surveys and open-ended interviews. Across eight HSTA organizations, 43 teen leaders participated in teaching the iCook 4-H program to 24 dyads. Increased frequency of culinary skills, physical activity and mealtime behavior were reported by youth. Almost all adults (93%) reported that their youth had learned kitchen skills and that the program provided youth-adult quality time and developed culinary skills. Youth echoed adult perceptions with additional themes of food safety and physical activity. HSTA teen leaders perceived the program to be successful and reported the training they received to implement the program was adequate 98% of the time. HSTA teachers found the program to be beneficial for HSTA students in improving leadership, confidence and responsibility. iCook 4-H was feasible to be disseminated through teen leaders in the HSTA program. This teen-led approach could serve as a model for youth health-related programming.

Description: IJERPH, Vol. 15, Pages 1401: Development of iGrow: A Curriculum for Youth/Adult Dyads to Increase Gardening Skills, Culinary Competence, and Family Meal Time for Youths and Their Adult Caregivers International Journal of Environmental Research and Public Health doi: 10.3390/ijerph15071401 Authors: Jade A. White Rebecca L. Hagedorn Nicole L. Waterland Makenzie L. Barr Oluremi A. Famodu Amy E. Root Adrienne A. White Sarah E. Colby Lisa Franzen-Castle Kendra K. Kattelmann Melissa D. Olfert This manuscript describes the development of a “learn by actively participating” curriculum for youth and their adult caregivers (dyad pair) to increase gardening skills, culinary competence, and family meal time. The curriculum was developed by integrating “iCook 4-H” and Junior Masters Gardener “Health and Nutrition from the Garden”, and “Essential Elements of 4-H Youth Development” curriculums with additional resources for gardening activities from the USDA’s My Plate and garden-based recipes. Expert reviewers (n = 11) provided feedback on the curriculum content, session structure, dosage, age appropriateness, and balance of the three focused areas. Seven family dyads (n = 14) participated in focus groups about understanding of need, interest, barriers, and potential engagement. A 10-week curriculum was developed and named: iGrow. The curriculum is a hands on, active learning program delivered through five, two-hour sessions using a family dyad model. Three main focus areas included gardening, culinary skills, and family conversation/interaction that all focused on togetherness. For the final iGrow curriculum, expert-level content review and feedback from focus group dyad pairs was used to revise the curriculum which further enhanced the approach and balance of the curriculum content. Focus group feedback supported appropriateness, dosage and learning objectives, and content depth. This curriculum has been developed to provide knowledge of gardening and culinary skills with the goal of increased consumption of fruit and vegetables.

Description: Journal of the American Chemical Society DOI: 10.1021/jacs.5b06390