Determining the Interaction Of Atg11cc2-3 with Its Protein Partners Using In Vitro Binding Assays

Autophagy is a mechanism of cellular upkeep by trafficking intracellular material to be degraded. Autophagy is known to be carried out by autophagy related proteins (Atg), yet the exact mechanism of how autophagy occurs has yet to be discovered. Due to its clinical relevance to conditions such as neurodegenerative and muscular diseases, a great deal of current research is being dedicated to further our understanding of how autophagy occurs. Atg11, a protein critical to a yeast’s ability to perform selective autophagy, may also hold many answers to selective autophagy within humans. Atg11 is a coiled-coil protein that interacts with Atg1, 9, 11, 20, 29, along with Ypt1 in selective autophagy. However, it is unknown how these interactions occur. Does Atg11 have multiple binding sites where it may bind to proteins simultaneously? Or does Atg11 have one competitive binding site where it can only bind with a single protein, and then release it before it may bind again? In this research we attempt to purify the binding portion of Atg11 so that it can be used to observe Atg11’s binding interactions with these proteins through a protein binding test mediated by a resin pulldown

The Feasibility of Developing a Computer Based Expert System to Mitigate Nuclear Power Plant Accidents

This study investigated the feasibility of developing a rule-based expert system to support nuclear plant operators in the mitigation of accidents. Human error in the use of Emergency Operating Procedures (EOPs) was the problem to be addressed. The goal was to determine if the Nuclear Plant Information System (NPIS) at one specific power plant would support development of an EOP operator aid to reduce the number of human errors. A review of the literature confirmed that human error is a recurring problem. This is particularly evident during high stress situations, such as accidents. A rule-based operator aid can reduce human performance errors. This made the research significant enough to justify its undertaking. Previous studies have developed rule-based operator aids for new plant design, but ignored nuclear plants constructed before the availability of computers. The data required for performance of each Emergency Operating Procedure step was identified. Individual step data requirements were compared to data presently available from the Nuclear Plant Information System. For needed data not directly available, alternative parameters were selected where possible. The alternative parameters provide the same plant information to the operator as that described in the Emergency Operating Procedure step. Parameters that cannot be monitored directly or by an alternative method are identified. This was documented in an EOP data matrix. Using the EOPs, a set of rules was developed for a 10, 000-gpm large break loss of coolant accident (LBLOCA). A plant specific simulator scenario for a LBLOCA was conducted. Data collection was performed during this scenario. A comparison of the collected data to the EOP rules determined all required information is not available. This was documented in an EOP rules matrix. A separate matrix compiled all parameters not directly on NPIS and without an acceptable alternative. The effect of each missing parameter on the mitigation strategy is documented. An EOP expert performed an independent verification of the rules matrix. This verifies correctness of the rules and the required data. A NPIS database expert performed an additional independent verification of unavailable NPIS data. This verified that the matrix data identified as unavailable from NPIS was correct. The study resulted in a set of recommendations for improving plant process computers, EOP procedures, and EOP development techniques. This approach may be used in other nuclear plants. Additional research avenues were identified

The multiflora rose as a living hedge fence

Cover title

Managing Insects on Texas Peanuts.

7 p

Managing Insects on Texas Peanuts.

7 p

Climate Change-Driven Cumulative Mountain Pine Beetle-Caused Whitebark Pine Mortality in the Greater Yellowstone Ecosystem

An aerial survey method called the Landscape Assessment System (LAS) was used to assess mountain pine beetle (Dendroctonus ponderosae)-caused mortality of whitebark pine (Pinus albicaulis) across the Greater Yellowstone Ecosystem (59,000 km2; GYE). This consisted of 11,942 km of flightlines, along which 4434 geo-tagged, oblique aerial photos were captured and processed. A mortality rating of none to severe (0–4.0 recent attack or 5.0–5.4 old attack) was assigned to each photo based on the amount of red (recent attack) and gray (old attack) trees visible. The method produced a photo inventory of 74 percent of the GYE whitebark pine distribution. For the remaining 26 percent of the distribution, mortality levels were estimated based on an interpolated mortality surface. Catchment-level results combining the photo-inventoried and interpolated mortality indicated that 44 percent of the GYE whitebark pine distribution showed severe old attack mortality (5.3–5.4 rating), 37 percent showed moderate old attack mortality (5.2–5.29 rating), 19 percent showed low old attack mortality (5.1–5.19 rating) and less than 1 percent showed trace levels of old attack mortality (5.0–5.09). No catchments were classified as recent attacks indicating that the outbreak of the early 2000’s has ended. However, mortality continues to occur as chronic sub-outbreak-level mortality. Ground verification using field plots indicates that higher LAS mortality values are moderately correlated with a higher percentage of mortality on the ground

Wee1-Regulated Apoptosis Mediated by the Crk Adaptor Protein in Xenopus Egg Extracts

Many of the biochemical reactions of apoptotic cell death, including mitochondrial cytochrome c release and caspase activation, can be reconstituted in cell-free extracts derived from Xenopus eggs. In addition, because caspase activation does not occur until the egg extract has been incubated for several hours on the bench, upstream signaling processes occurring before full apoptosis are rendered accessible to biochemical manipulation. We reported previously that the adaptor protein Crk is required for apoptotic signaling in egg extracts (Evans, E.K., W. Lu, S.L. Strum, B.J. Mayer, and S. Kornbluth. 1997. EMBO (Eur. Mol. Biol. Organ.) J. 16:230–241). Moreover, we demonstrated that removal of Crk Src homology (SH)2 or SH3 interactors from the extracts prevented apoptosis. We now report the finding that the relevant Crk SH2-interacting protein, important for apoptotic signaling in the extract, is the well-known cell cycle regulator, Wee1. We have demonstrated a specific interaction between tyrosine-phosphorylated Wee1 and the Crk SH2 domain and have shown that recombinant Wee1 can restore apoptosis to an extract depleted of SH2 interactors. Moreover, exogenous Wee1 accelerated apoptosis in egg extracts, and this acceleration was largely dependent on the presence of endogenous Crk protein. As other Cdk inhibitors, such as roscovitine and Myt1, did not act like Wee1 to accelerate apoptosis, we propose that Wee1–Crk complexes signal in a novel apoptotic pathway, which may be unrelated to Wee1's role as a cell cycle regulator

Recording plasticity in neuronal activity in the rodent intrinsic cardiac nervous system using calcium imaging techniques

The intrinsic cardiac nervous system (ICNS) is composed of interconnected clusters of neurons called ganglionated plexi (GP) which play a major role in controlling heart rate and rhythm. The function of these neurons is particularly important due to their involvement in cardiac arrhythmias such as atrial fibrillation (AF), and previous work has shown that plasticity in GP neural networks could underpin aberrant activity patterns that drive AF. As research in this field increases, developing new techniques to visualize the complex interactions and plasticity in this GP network is essential. In this study we have developed a calcium imaging method enabling the simultaneous recording of plasticity in neuronal activity from multiple neurons in intact atrial GP networks. Calcium imaging was performed with Cal-520 AM labeling in aged spontaneously hypertensive rats (SHRs), which display both spontaneous and induced AF, and age-matched Wistar Kyoto (WKY) controls to determine the relationship between chronic hypertension, arrhythmia and GP calcium dynamics. Our data show that SHR GPs have significantly larger calcium responses to cholinergic stimulation compared to WKY controls, as determined by both higher amplitude and longer duration calcium responses. Responses were significantly but not fully blocked by hexamethonium, indicating multiple cholinergic receptor subtypes are involved in the calcium response. Given that SHRs are susceptible to cardiac arrhythmias, our data provide evidence for a potential link between arrhythmia and plasticity in calcium dynamics that occur not only in cardiomyocytes but also in the GP neurons of the heart

Quantitatively monitoring the resilience of patterned vegetation in the Sahel

Patterning of vegetation in drylands is a consequence of localized feedback mechanisms. Such feedbacks also determine ecosystem resilience—i.e. the ability to recover from perturbation. Hence, the patterning of vegetation has been hypothesized to be an indicator of resilience, that is, spots are less resilient than labyrinths. Previous studies have made this qualitative link and used models to quantitatively explore it, but few have quantitatively analysed available data to test the hypothesis. Here we provide methods for quantitatively monitoring the resilience of patterned vegetation, applied to 40 sites in the Sahel (a mix of previously identified and new ones). We show that an existing quantification of vegetation patterns in terms of a feature vector metric can effectively distinguish gaps, labyrinths, spots, and a novel category of spot–labyrinths at their maximum extent, whereas NDVI does not. The feature vector pattern metric correlates with mean precipitation. We then explored two approaches to measuring resilience. First we treated the rainy season as a perturbation and examined the subsequent rate of decay of patterns and NDVI as possible measures of resilience. This showed faster decay rates—conventionally interpreted as greater resilience—associated with wetter, more vegetated sites. Second we detrended the seasonal cycle and examined temporal autocorrelation and variance of the residuals as possible measures of resilience. Autocorrelation and variance of our pattern metric increase with declining mean precipitation, consistent with loss of resilience. Thus, drier sites appear less resilient, but we find no significant correlation between the mean or maximum value of the pattern metric (and associated morphological pattern types) and either of our measures of resilience