Effects of Triclopyr on Variable-Leaf Watermilfoil

The objective of the study described here was to determine the effect on variable-leaf watermilfoil of various combinations of triclopyr concentrations and exposure times using dosage rates that controlled Eurasian watermilfoil under laboratory and field conditions (Netherland and Getsinger 1992, Getsinger et al. 1997, Petty et al. 1998)

Subcellular partitioning of MRP RNA assessed by ultrastructural and biochemical analysis.

A small RNA encoded within the nucleus is an essential subunit of a RNA processing endonuclease (RNase MRP) hypothesized to generate primers for mitochondrial DNA replication from the heavy strand origin of replication. Controversy has arisen, however, concerning the authenticity of an intramitochondrial pool of MRP RNA, and has called into question the existence of pathways for nucleo-mitochondrial transport of nucleic acids in animal cells. In an effort to resolve this controversy, we combined ultrastructural in situ hybridization and biochemical techniques to assess the subcellular partitioning of MRP RNA. Cryosections of mouse cardiomyocytes were hybridized with biotin-labeled RNA probes complementary to different regions of MRP RNA and varying in length from 115 to 230 nucleotides, followed by immunogold labeling. In addition, we transfected mouse C2C12 myogenic cells with constructs bearing mutated forms of the mouse MRP RNA gene and compared the relative abundance of the resulting transcripts to that of control RNAs within whole cell and mitochondrial fractions. In the former analysis we observed preferential localization of MRP RNA to nucleoli and mitochondria in comparison to the nucleoplasm and cytoplasm. In the latter series of studies we observed that wild-type MRP RNA partitions to the mitochondrial fraction by comparison to other RNA transcripts that are localized to the extramitochondrial cytoplasmic space (28S rRNA) or to the nucleoplasm (U1 snRNA). Deletions within 5' or 3' regions of the MRP RNA gene produced transcripts that remain competent for mitochondrial targeting. In contrast, deletion of the midportion of the coding region (nt 118 to 175) of the MRP RNA gene resulted in transcripts that fail to partition to the mitochondrial fraction. We conclude that an authentic intramitochondrial pool of MRP RNA is present in these actively respiring cells, and that specific structural determinants within the MRP RNA molecule permit it to be partitioned to mitochondria

MR415: Why Not Tame the Wild Blueberry

A discussion of two studies of different methods of propagating lowbush blueberry plants. These methods could be used for introducing blueberry plants into existing fields to improve field cover, or to start a blueberry field from scratch.https://digitalcommons.library.umaine.edu/aes_miscreports/1005/thumbnail.jp

B852: Organic Wild Blueberry Production

Recent research carried out under the auspices of a USDA organic transition grant resulted in a better understanding of the interaction of wild blueberry production tactics such as pruning method, soil pH reduction by sulfur (S) application, and organic fertilizer rates on wild blueberry growth, development, and yield. This bulletin is the product of what we have learned over the past four years of this research project.https://digitalcommons.library.umaine.edu/aes_bulletin/1002/thumbnail.jp

Determinants of depressive symptom trajectories among older adults in community and treatment settings

Sub-diagnostic depression, sleep, and circadian rest-activity rhythm (CAR) syndromes are common in late-life, but their characteristics, prevalence, and relations to future depression are unclear. We characterized commonly occurring sleep, CAR, and depressive sign/symptom patterns using a data-driven approach applied to a large population-based study of older men. We next examined relationships of these baseline syndromes with longitudinal change in depressive symptoms. Common (32.44%) probable depressive syndromes were characterized by somatic/apathy symptoms; a subset (5.74%) with only limited somatic/apathy symptoms also had emotional-related impairment. Subjective complaints without objectively (actigraph) assessed disturbances characterized two distinct classes of men (totaling 37.46%); a pattern of objective disturbance (including greater sleep fragmentation with probable prolonged sleep latency or short (<5 hour) sleep duration) occurred in both the presence (8.87%) and absence (8.51%) of subjective complaints. Only 32.18% appeared to be free of a non-normative CAR parameter; 8 classes were distinguished by activity timing, levels, and the active period length. Baseline sleep and depression latent classes were not meaningfully associated with rates of change in depression severity. The rate of increase in depressive symptoms was higher for classes with later activity and for a class with dampened, earlier, and compressed activity combined. Future work should assess the modifiability of the identified markers of depressive symptom increases through preventative interventions. Nevertheless, there remains a need to understand of mechanisms of variability in pharmacological treatment response among older adults with major depressive disorder (MDD). We therefore assessed prognostic factors associated with distinct trajectories of depressive symptom change over 12-weeks of open-label Venlafaxine XR treatment for MDD. Only about 42% of participants exhibited a clear response, and the clinical prognostic factors linked to unique patterns of non-response included: worse depressive severity, longer illness duration, prior adequate pharmacological treatment, and worse list recognition performance. Overall, this work has public health relevance by providing a novel description of common sleep-wake/depressive syndromes in the community and distinct symptom trajectories found when pharmacologically treating MDD in the clinic. There is a need to integrate the identified prognostic markers with neurobiological research towards a valid predictive science of depression pathogenesis, prevention, and treatment

TB203: Recent Advances in the Biology and Genetics of Lowbush Blueberry

For lowbush blueberries, this publication presents an in-depth look at the biology and genetics of lowbush blueberry. The authors provide details on its genetic composition and the outline the usefulness of various biochemical, genomic, and other markers in studying the plants genetic structure. The authors also provide an overview of the plant’s economic value to Maine, nutritional value, and its life history.https://digitalcommons.library.umaine.edu/aes_techbulletin/1008/thumbnail.jp

A mitochondrial import receptor for the ADP/ATP carrier

We have identified a mitochondrial outer membrane protein of 72 kd (MOM72) that exhibits the properties of an import receptor for the ADP/ATP carrier (AAC), the most abundant mitochondrial protein. Monospecific antibodies and Fab fragments against MOM72 selectively inhibit import of AAC at the level of specific binding to the mitochondria. AAC bound to the mitochondrial surface is coprecipitated with antibodies against MOM72 after lysis of mitochondria with detergent. MOM72 thus has a complementary function to that of MOM19, which acts as an import receptor for the majority of mitochondrial proteins studied so far but not for the AAC. The import pathway of the precursor of MOM72 appears to involve MOM19 as receptor

Transport of proteins into the various subcompartments of mitochondria

The import of proteins into mitochondria is an intricate process comprised of multiple steps. The first step involves the sorting of cytosolically synthesized precursor proteins to the mitochondrial surface. There precursor proteins are recognized by specific receptors which deliver them to the general import site present in the outer membrane. The second stage of import involves a series of complex intraorganelle sorting events which results in the delivery of the proteins to one of the four possible submitochondrial destinations, namely the outer and inner membranes, the matrix and intermembrane space. Here in this review, we discuss the current knowledge on these intramitochondrial sorting events. We especially focus on targetting of proteins to the intermembrane space. Sorting to the intermembrane space represents a particularly interesting situation, as at least three separate targetting pathways to this subcompartment are known to exist