Posted by: princekhaled | April 8, 2009

April & May 2009

Amin AA, Menon RA, Reid KJ, Harris WS(*), & Spertus JA. (2008).
Acute Coronary Syndrome Patients with Depression have Low Blood Cell Membrane Omega-3 Fatty Acid Levels.
Psychosomatic Medicine 70(8): 856-862.

Objective: To determine the extent to which levels of membrane eicosapentaenoic (EPA)+docosahexaenoic acids (DHA) (the omega-3 index) were associated with depression in patients with acute coronary syndrome (ACS). Depression is associated with worse cardiovascular (CV) outcomes in patients with ACS. Reduced levels of blood cell membrane omega-3 (n-3) fatty acids (FAs), an emerging risk factor for both CV disease and depression, may help to explain the link between depression and adverse CV outcomes. Methods: We measured membrane FA composition in 759 patients with confirmed ACS. The analysis included not only EPA and DHA but also the n-6 FAs linoleic and arachidonic acids (LA and AA). Depressive symptoms were measured with the Patient Health Questionnaire-9 (PHQ). Multivariable linear regression was used to adjust for demographic and clinical characteristics. Results: There was a significant inverse relationship between the n-3 index and depressive symptoms (PHQ) in the fully adjusted model (p = .034). For every 4.54% point rise in the n-3 index, there was a 1-point decline in depressive symptoms. In contrast to the n-3 FAs, membrane levels of the n-6 FAs LA and AA were not different between depressed and nondepressed ACS patients. Conclusion: We found an inverse relationship between the n-3 index and the prevalence of depressive symptoms in patients with ACS. Therefore, this study supports the hypothesis that reduced n-3 FA tissue levels are a common and potentially modifiable link between depression and adverse CV outcomes.

(*) Sanford School of Medicine, University of South Dakota, Vermillion, SD

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Ballal A(*), Ray B(*), & Manna AC(*). (2009).
sarZ, a sarA Family Gene, is Transcriptionally Activated by MgrA and is Involved in the Regulation of Genes Encoding Exoproteins in Staphylococcus aureus.
Journal of Bacteriology 191(5): 1656-1665.

The expression of genes involved in the pathogenesis of Staphylococcus aureus is controlled by global regulatory loci, including two-component regulatory systems and transcriptional regulators (e.g., sar family genes). Most members of the SarA family have been partially characterized and shown to regulate a large numbers of target genes. Here, we describe the characterization of sarZ, a sarA paralog from S. aureus, and its regulatory relationship with other members of its family. Expression of sarZ was growth phase dependent with maximal expression in the early exponential phase of growth. Transcription of sarZ was reduced in an mgrA mutant and returned to a normal level in a complemented mgrA mutant strain, which suggests that mgrA acts as an activator of sarZ transcription. Purified MgrA protein bound to the sarZ promoter region, as determined by gel shift assays. Among the sarA family of genes analyzed, inactivation of sarZ increased sarS transcription, while it decreased agr transcription. The expression of potential target genes involved in virulence was evaluated in single and double mutants of sarZ with mgrA, sarX, and agr. Northern and zymogram analyses indicated that the sarZ gene product played a role in regulating several virulence genes, particularly those encoding exoproteins. Gel shift assays demonstrated nonspecific binding of purified SarZ protein to the promoter regions of the sarZ-regulated target genes. These results demonstrate the important role played by SarZ in controlling regulatory and virulence gene expression in S. aureus.

(*) Sanford School of Medicine, University of South Dakota, Vermillion, SD

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Ballal A(*). (2009).
Regulation of Superoxide Dismutase (sod) Genes by SarA in Staphylococcus aureus.
Journal of Bacteriology 191(10): 3301-3310.

The scavenging of reactive oxygen species (ROS) within cells is regulated by several interacting factors, including transcriptional regulators. Involvement of sarA family genes in the regulation of proteins involved in the scavenging of ROS is largely unknown. In this report, we show that under aerobic conditions, the levels of sodM and sodA transcription, in particular the sodM transcript, are markedly enhanced in the sarA mutant among the tested sarA family mutants. Increased levels of sod expression returned to near the parental level in a single-copy sarA complemented strain. Under microaerophilc conditions, transcription of both sodM and sodA was considerably enhanced in the sarA mutant compared to the wild-type strain. Various genotypic, phenotypic, and DNA binding studies confirmed the involvement of SarA in the regulation of sod transcripts in different strains of Staphylococcus aureus. The sodA mutant was sensitive to an oxidative stress-inducing agent, methyl viologen, but the sarA sodA double mutant was more resistant to the same stressor than the single sodA mutant. These results suggest that overexpression of SodM, which occurs in the sarA background, can rescue the methyl viologen-sensitive phenotype observed in the absence of the sodA gene. Analysis with various oxidative stress-inducing agents indicates that SarA may play a greater role in modulating oxidative stress resistance in S. aureus. This is the first report that demonstrates the direct involvement of a regulatory protein (SarA) in control of sod expression in S. aureus.

(*) Sanford School of Medicine, University of South Dakota, Vermillion, SD

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Chen DG(*), & Lio YL(**). (2009).
A Novel Estimation Approach for Mixture Transition Distribution Model in High-Order Markov Chains.
Communications in Statistics: Simulation and Computation 38(5): 990-1003.

A transformation is proposed to convert the nonlinear constraints of the parameters in the mixture transition distribution (MTD) model into box-constraints. The proposed transformation removes the difficulties associated with the maximum likelihood estimation (MLE) process in the MTD modeling so that the MLEs of the parameters can be easily obtained via a hybrid algorithm from the evolutionary algorithms and/or quasi-Newton algorithms for global optimization. Simulation studies are conducted to demonstrate MTD modeling by the proposed novel approach through a global search algorithm in R environment. Finally, the proposed approach is used for the MTD modelings of three real data sets.

(*) Sanford School of Medicine, University of South Dakota, Sioux Falls, SD
(**) Department of Medicine, University of South Dakota, Vermillion, SD

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Christopher MS, & Skillman GD(*). (2009).
Exploring the Link Between Self-Construal and Distress Among African American and Asian American College Students.
Journal of College Counseling 12(1): 44-56.

The authors investigated ethnicity, self-construal, and distress among African American and Asian American college students, African American students expressed more salient independent self-construals, whereas Asian American students expressed more salient interdependent self-construals. As hypothesized, among African American participants, distress was positively related to interdependent self-construal and negatively associated with independent self-construal. Contrary to prediction, the same pattern was found for Asian American participants. Multicultural clinical practice implications are presented.

(*) Psychology Department, University of South Dakota, Vermillion, SD

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Engeman JM(*), Aspinwall N, & Mabee PM(*). (2009).
Development of the Pharyngeal Arch Skeleton in Catostomus commersonii Teleostei: Cypriniformes.
Journal of Morphology 270(3): 291-305.

Skeletal elements of the gill arches of adult cypriniform fishes vary widely in number, size, and shape and are important characters in morphologically based phylogenetic studies. Understanding the developmental basis for this variation is thus phylogenetically significant but also important in relation to the many developmental genetic and molecularly based studies of the early developing and hence experimentally tractable gill arches in the zebrafish, a cyprinid cypriniform. We describe the sequence of the chondrification and ossification of the pharyngeal arches and associated dermal bones from Catostomus commersonii (Catostomidae, Cypriniformes) and make selected comparisons to other similarly described pharyngeal arches. We noted shared spatial trends in arch development including the formation of ventral cartilages before dorsal and anterior cartilages before posterior. Qualitatively variable gill arch elements in Cypriniformes including pharyngobranchial 1, pharyngobranchial 4, and the sublingual are the last such elements to chondrify in C. commersonii. We show that the sublingual bone in C. commersonii has two cartilaginous precursors that fuse and ossify to form the single bone in adults. This indicates homology of the sublingual in catostomids to the two sublingual bones in the adults of cobitids and balitorids. Intriguing patterns of fusion and segmentation of the cartilages in the pharyngeal arches were discovered. These include the individuation of the basihyal and anterior copula through segmentation of a single cartilage rod, fusion of cartilaginous basibranchials 4 and 5, and fusion of hypobranchial 4 with ceratobranchial 4. Such  fluidity  in cartilage patterning may be widespread in fishes and requires further comparative developmental studies.

(*) Department of Biology, University of South Dakota, Vermillion, SD

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Epperson BK, Telewski FW, & Willyard A(*). (2009).
Chloroplast Diversity in a Putative Hybrid Swarm of Ponderosae (Pinaceae).
American Journal of Botany 96(3): 707-712.

The Ponderosae subsection of the genus Pinus contains numerous taxa in disjunct mountain ranges of southern Arizona and New Mexico, differing for several leaf and cone traits, key among which is the number of leaf needles per fascicle. Trees with three needles are often found together with trees having five needles and mixed numbers. One taxonomic hypothesis is that there are swarms of hybrids between P. ponderosa and P. arizonica. A second hypothesis is that there are spatial mixtures of two separate taxa, five-needle P. arizonica and a “taxon X” containing three needle and mixed needle trees. We genotyped chloroplasts in one putative hybrid swarm on Mt. Lemmon using microsatellite markers and show that cpDNA is almost completely differentiated between two separate morphotypes corresponding to P. arizonica and “taxon X.” Little if any introgression has occurred on Mt. Lemmon, and the simplest explanation is that little or no effective hybridization has occurred. Further results indicate that not only is taxon X not of hybrid origin, it is more closely related to nonregional Ponderosae other than P. ponderosa and P. arizonica. The results further suggest that other putative hybrid swarms in the region are also spatial mixtures of distinct taxa.

(*) Department of Biology, University of South Dakota, Vermillion, SD

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Fairholm MR(*), & Card M(*). (2009).
Perspectives of Strategic Thinking: From Controlling Chaos to Embracing It.
Journal of Management & Organization 15(1): 17-30.

There is an increasing focus in today’s organization on measuring results and calculating return on investment. Efforts of administrators today to control organizational endeavors are essential and generally aligned with current best practices. Control mechanisms, however, ultimately prove to be only part of the puzzle. Strategic planning, encompassing such activities as planning, performance measurement, program budgeting, and the like, has proven to be very useful but limited. It is a technical fix that gets at only part of the question of organizational effectiveness and only deals with some organizational dilemmas. In the face of such realities, the notion of strategic thinking emerges to fill the gaps and overcome the limitations that experience with strategic planning has proven to exhibit. This paper presents an integration of leadership ideas, strategic thinking and traditional planning activities in an effort to make important connections and important distinctions.

(*) Political Science Department and WO Farber Center for Civic Leadership, University of South Dakota, Vermillion, SD

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Freeburg E(*), Goyeneche A(*), Seidel E(*), & Telleria C(*). (2009).
Resistance to Cisplatin Does Not Affect Sensitivity of Human Ovarian Cancer Cell Lines to Mifepristone Cytotoxicity.
Cancer Cell International 9(1): 4-4.

The prototypical antiprogestin mifepristone exhibits potent growth inhibition activity towards ovarian cancer cells in vitro and in vivo. The aim of this research was to establish whether mifepristone is capable of inhibiting cell proliferation and inducing apoptotic cell death regardless of the degree of sensitivity ovarian cancer cells exhibit to cisplatin.

(*) Sanford School of Medicine, University of South Dakota, Vermillion, SD

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Frueh BC, Grubaugh AL, Cusack KJ, Kimble MO, Elhai JD(*), & Knapp RG. (2009).
Exposure-based Cognitive-behavioral Treatment of PTSD in Adults with Schizophrenia or Schizoaffective Disorder: A Pilot Study.
Journal of Anxiety Disorders 23(5): 665-675.

In an open trial design, adults (n=20) with posttraumatic stress disorder (PTSD) and either schizophrenia or schizoaffective disorder were treated via an 11-week cognitive-behavioral intervention for PTSD that consisted of education, anxiety management therapy, social skills training, and exposure therapy, provided at community mental health centers. Results offer preliminary hope for effective treatment of PTSD among adults with schizophrenia or schizoaffective disorder, especially among treatment completers (n=13). Data showed significant PTSD symptom improvement, maintained at 3-month follow-up. Further, 12 of 13 completers no longer met criteria for PTSD or were considered treatment responders. Clinical outcomes for other targeted domains (e.g., anger, general mental health) also improved and were maintained at 3-month follow-up. Participants evidenced high treatment satisfaction, with no adverse events. Significant improvements were not noted on depression, general anxiety, or physical health status. Future directions include the need for randomized controlled trials and dissemination efforts.

(*) Disaster Mental Health Institute, University of South Dakota, Vermillion, SD

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Gapp SC, Zalud G, & Pietrzak D. (2009).
End of Intervention Reading Recovery Decisions and Subsequent Achievement.
Reading Improvement 46(1): 9-18.

The article presents a study which examines the relationship between end of Reading Recovery intervention decisions and predicting later reading achievement. The findings reveal that end of intervention decision did predict performance level categories. Study shows that students who successfully discontinued the need of the Reading Recovery intervention tended to perform in the proficient to advanced levels in third, fourth and fifth grades.

(*) Department of Education, University of South Dakota, Vermillion, SD

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Harris WS(*), Mozaffarian D, Lefevre M, Toner CD(*), Colombo J, Cunnane SC, Holden JM, Klurfeld DM, Morris MC, & Whelan J. (2009).
Towards Establishing Dietary Reference Intakes for Eicosapentaenoic and Docosahexaenoic Acids.
Journal of Nutrition 139(4): 804S-819S.

The article presents a discussion regarding the use of (n-3) long-chain polyunsaturated fatty acids (PUFA) for mitigating the occurrence of morbidity and mortality brought about by chronic diseases. The need for clearly-defined Dietary Reference Intakes (DRI) for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is noted, mentioning that EPA+DHA intake has been found to hold a possible connection to the mitigation of the risk of morbidity or mortality associated with chronic diseases such as coronary heart disease (CHD), cancer, and cognitive decline.

(*) Sanford School of Medicine, University of South Dakota, Vermillion, SD

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Long L, Braunstein R(*), Manning B, & Anderson WD(*). (2008).
Understanding Contextual Differences in American Indian Criminal Justice.
American Indian Culture and Research Journal 32(4): 41-65.

The findings of the 1999 and 2004 Bureau of Justice Statistics (BJS) studies about crime and victimization in the American Indian community deviate from the experience and expectations of South Dakota’s current attorney general. The BJS studies focused on the 10-year period from 1992 to 2002 and found that non-Indians had committed 66 percent of all crimes against American Indian victims. The experience of prosecutors in and around Indian country in South Dakota was inconsistent with the BJS findings. Furthermore, the BJS reports deviate in significant ways from academic literature describing violent crime victimization within and outside Indian country. Combined, these concerns produced an overall sense that something was wrong in the findings of the BJS studies that necessitated further investigation. A detailed study of the state of South Dakota’s criminal justice system, which contradicted the BJS studies’ findings, found that the BJS had ignored federal case data in their research.

(*) Political Science Department and WO Farber Center for Civic Leadership, University of South Dakota, Vermillion, SD

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Lowry CA, Hale MW, Plant A, Windle RJ, Shanks N, Wood SA, Ingram CD, Renner KJ(*), Lightman SL, & Summers CH(*). (2009).
Fluoxetine Inhibits Corticotropin-releasing Factor (CRF)-induced Behavioural Responses in Rats.
Stress: The International Journal on the Biology of Stress 12(3): 225-239.

Corticotropin-releasing factor (CRF) is a potent neuromodulator of stress-related behaviour but the neural mechanisms underlying these effects are not clear. Studies were designed to test the hypothesis that CRF-induced behavioural arousal involves interactions with brainstem serotonergic systems. To examine interactions between CRF and serotonergic systems in the regulation of behaviour, CRF (1 μg, intracerebroventricular (i.c.v.)) or vehicle was infused in the presence or absence of the selective serotonin re-uptake inhibitor fluoxetine (0, 0.1, 1 or 10 mg/kg, intravenous (i.v.)). Fluoxetine was used at these doses because it is known to decrease serotonin cell firing rates while increasing extracellular serotonin concentrations in select forebrain regions. We then measured behavioural, neurochemical and endocrine responses. CRF increased locomotion and spontaneous non-ambulatory motor activity (SNAMA) in the home cages. Fluoxetine decreased tissue 5-hydroxyindoleacetic acid concentrations, a measure of serotonin metabolism, in specific limbic brain regions of CRF-treated rats (nucleus accumbens shell region, entorhinal cortex, central nucleus of the amygdala). Furthermore, fluoxetine inhibited CRF-induced SNAMA. CRF and fluoxetine independently increased plasma corticosterone concentrations, but the responses had distinct temporal profiles. Overall, these data are consistent with the hypothesis that CRF-induced facilitation of behavioural activity is dependent on brainstem serotonergic systems. Therefore, fluoxetine may attenuate or alleviate some behavioural responses to stress by interfering with CRF-induced responses.

(*) Department of Biology, University of South Dakota, Vermillion, SD

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Naifeh J(*), North T, Davis J, Reyes G, Logan C, & Elhai J(*). (2008).
Clinical Profile Differences Between PTSD-Diagnosed Military Veterans and Crime Victims.
Journal of Trauma & Dissociation 9(3): 321-334.

Few studies have conducted symptom comparisons across different trauma-exposed populations. Evidence linking different types of trauma to variations in clinical presentation would have potential implications for the assessment and treatment of trauma-related psychopathology. The current study evaluated whether military veterans (n = 187) and civilian crime victims (n = 47) diagnosed with posttraumatic stress disorder differ in their self-reported posttraumatic symptoms as measured by the Trauma Symptom Inventory. A multivariate profile analysis revealed that military-related trauma is associated with more severe posttraumatic symptoms than criminal victimization and suggested that these 2 types of trauma have statistically distinct symptom profiles. Some potential implications of these findings and considerations for future research are discussed.

(*) Disaster Mental Health Institute, University of South Dakota, Vermillion, SD

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Newswander CB(*), & Newswander LK(*). (2009).
“Born Again” Govermentality: The Faith-based Initiative as Administrative Agent.
International Journal of Organization Theory & Behavior 12(1): 27-54.

A careful study demonstrates that President Bush has implemented the faith-based initiative as a method of governmentality, one which appears to be biased toward Christianity. This paper examines the definition of Foucault’s governmentality as it relates to the ever-expanding structure of contemporary American governance and justifies the categorization of faith-based initiatives as an example of pastoral power. Ultimately, these arguments characterize the current state of governmentality as “born-again,” and call specific attention to what appears to be a strong affiliation of charitable choice” with evangelical Christianity. By relying on evangelical Christianity to govern, the pastoral-panopticon coupled with governmental resources has brought back an older method of regulation which is less obvious in its intrusion, and more dangerous for it.

(*) University of South Dakota, Vermillion, SD

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Prentice C(*). (2009).
Relational Dialectics Among In-Laws.
Journal of Family Communication 9(2): 67-89.

This interpretive study gathered information from interviews with 42 participants who had recently acquired in-laws. Rather than examining specific dyads on in-laws, this study explored how the entry of the newcomer into a family group created tensions that were managed as the newcomer advanced through the stages of socialization into the group. Relational dialectics analysis indicated that in-laws experienced the external dialectical tensions of inclusion/seclusion, conventionality/uniqueness, and revelation/concealment. However, the tensions manifested in unique ways and were managed with a variety of strategies, some of them unique to the in-law relationship. New strategies for managing these tensions included mediating the communication between some in-laws, while seeking closer direct communication among adult siblings (-in-law). Through new relationships with adult siblings, the family was transformed from the family-of-childhood to the family-of-adulthood. These findings suggest that in-law relationships deserve further study.

(*) Department of Communication Studies, University of South Dakota, Vermillion, SD

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Richardson JD, Pekevski J(*), & Elhai JD(*). (2009).
Post-traumatic Stress Disorder and Health Problems Among Medically Ill Canadian Peacekeeping Veterans.
Australian & New Zealand Journal of Psychiatry 43(4): 366-372.

Objective: The aim of the present study was to examine the relationship between post-traumatic stress disorder (PTSD) symptom severity and four significant health conditions (gastrointestinal disorders, musculoskeletal problems, headaches, and cardiovascular problems). Method: Participants included 707 Canadian peacekeeping veterans with service-related disabilities, from a random, national Canadian survey, who had been deployed overseas. Results: PTSD severity was significantly related to gastrointestinal disorders, musculoskeletal problems, and headaches, but not to cardiovascular problems. Controlling for demographic factors did not affect PTSD’s relationships with the three significant health conditions. Conclusions: The present study supports previous work in finding consistent relations between PTSD severity and specific types of medical problems.

(*) Disaster Mental Health Institute, University of South Dakota, Vermillion, SD

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Roseman CP(*), Ritchie M, & Laux JM. (2009).
A Restorative Justice Approach to Empathy Development in Sex Offenders: An Exploratory Study.
Journal of Addictions & Offender Counseling 29(2): 96-109.

The article present information on an exploratory study which described sex offender treatment using a restorative justice approach to examine the shame, guilt, and empathy development of convicted sexual offenders. It offers a brief overview of the history of dealing with sex offenders in the U.S. It explores the trends for treating sex offenders. It also discusses the impact of guilt and shame on empathy development. It describes the application of two instruments used in the study: the Balanced Emotional Empathy Scale and the Personal Feelings Questionnaire-2.

(*) Department of Education: Counseling and Psychology, University of South Dakota

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Sabirzhanova I(*), Sabirzhanov B(*), Bjordahl J(*), Brandt J(*), Jay PY, & Clark TG(*). (2009).
Activation of Tolloid-like 1 Gene Expression by the Cardiac Specific Homeobox Gene Nkx2-5.
Development, Growth & Differentiation 51(4): 403-410.

Mammalian Tolloid-like 1 (Tll-1) is a pleiotropic metalloprotease that is expressed by a small subset of cells within the precardiac mesoderm and is necessary for proper heart development. Following heart tube formation Tll-1 is expressed by the endocardium and regions of myocardium overlying the region of the muscular interventricular septum. Mutations in Tll-1 lead to embryonic lethality due to cardiac defects. We demonstrate that the Tll-1 promoter contains Nkx2–5 binding sites and that the Tll-1 promoter is activated by and directly binds Nkx2–5. Tll-1 expression is ablated by a dominant negative Nkx2–5 or by mutation of the Nkx2–5 binding sites within the Tll-1 promoter. In vivo, Tll-1 expression is decreased in the hearts of Nkx2–5 knockout embryos when compared with hemizygous and wild-type embryos. These results show that Nkx2–5 is a direct activator of Tll-1 expression and provide insight into the mechanism of the defects found in both the Tll-1 and Nkx2–5 knockout mice.

(*) Sanford School of Medicine, University of South Dakota, Vermillion, SD

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Shokeen S(*), Greenfield TJ, Ehli EA(*), Rasmussen J(*), Perrault BE(*), & Weaver KE(*). (2009).
An Intramolecular Upstream Helix Ensures the Stability of a Toxin-Encoding RNA in Enterococcus faecalis.
Journal of Bacteriology 191(5): 1528-1536.

The par stability determinant is required for the stable inheritance of the plasmid pAD1 in its native host, Enterococcus faecalis. It is the only antisense RNA-regulated addiction module identified to date in gram-positive bacteria. It encodes two small, convergently transcribed RNAs, RNA I and RNA II. RNA I encodes the Fst toxin and RNA II acts as the antitoxin by interacting with RNA I posttranscriptionally. As the toxin-encoding component of the system, it is important that RNA I is more stable than RNA II. This study reveals that a helix sequestering the 5′ end of RNA I plays a crucial role in maintaining the stability of the RNA I. An adjacent structure previously determined to regulate Fst translation was not required to enhance stability. Results indicated that endoribonuclease J2 contributes significantly to the degradation of a mutant disrupting the upstream helix (UH) of RNA I in Bacillus subtilis. Finally, it was shown that interaction with RNA II stabilized the UH mutant of RNA I.

(*) Sanford School of Medicine, University of South Dakota, Vermillion, SD

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Stromberg JC, Rychener TJ, & Dixon MD(*). (2009).
Return of Fire to a Free-Flowing Desert River: Effects on Vegetation.
Restoration Ecology 17(3): 327-338.

After a long period in which fuel loads were sparse, fire recently has occurred with high frequency in the ungrazed riparian zone of the Upper San Pedro River in southern Arizona’s Chihuahuan Desert. We studied four accidental fires that occurred during 1994–2003 (two in different years at the same site). Woody vegetation was contrasted between three burned sites and matched spatial controls, and before and after the most recent fire. Herbaceous vegetation was sampled in multiple years producing a chronosequence of time since fire (from 4 months to 8 years). Riparian fire was associated with reductions in woody plant species diversity and canopy cover. In contrast, fire caused a short-term (2 year) pulse of herbaceous plant diversity, driven by annual species, and persistent increase in herbaceous cover. Path analysis indicated that the increase in herbaceous cover was mediated in part by the reduction in tree canopy cover. Ordination (nonmetric multidimensional scaling) and regression analysis also indicated that canopy cover and/or fire played a role in structuring the herbaceous community, although its effects were secondary to that of hydrologic factors (stream flow rate, seasonal flood size). By converting riparian forests to grasslands and savannahs, fire may be shifting structure of the Upper San Pedro floodplain vegetation closer toward conditions present during past centuries when fire was frequent in the upland desert grasslands and embedded riparian corridor.

(*) Department of Biology, University of South Dakota, Vermillion, SD

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Swanson DL(*), Sabirzhanov B(**), VandeZande A(**), & Clark TG(**). (2009).
Seasonal Variation of Myostatin Gene Expression in Pectoralis Muscle of House Sparrows (Passer domesticus) Is Consistent with a Role in Regulating Thermogenic Capacity and Cold Tolerance.
Physiological & Biochemical Zoology 82(2): 121-128.

Winter acclimatization in small birds overwintering in cold climates, including house sparrows (Passer domesticus), is associated with improved cold tolerance, elevated summit metabolic rates (M<sub>sum</sub>= maximum cold-induced metabolic rate), and increased pectoralis muscle mass compared to summer birds. Myostatin is a potent autocrine/paracrine inhibitor of skeletal muscle growth in mammals and birds and is a potential candidate for regulation of seasonal phenotypic flexibility in birds. As a first step toward examining such a role for myostatin in small birds, we measured summer and winter gene expression of myostatin and its potential metalloproteinase activators TLL-1 and TLL-2 in house sparrows from southeastern South Dakota. Gene expression of myostatin decreased significantly in winter, with summer values exceeding winter values by 1.52-fold. Moreover, gene expression of TLL-1 was also significantly reduced in winter, with summer values exceeding winter values by 1.55-fold. These data are consistent with the hypothesis that the winter increases in pectoralis muscle mass, M<sub>sum</sub>, and cold tolerance in house sparrows are mediated by reduced levels of myostatin and its activator TLL-1, and they suggest the possibility that myostatin may be a common mediator of phenotypic flexibility of muscle mass in birds.

(*) Department of Biology, University of South Dakota, Vermillion, SD
(**) Sanford School of Medicine, University of South Dakota, Vermillion, SD

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Zheng Z(*), & Keifer J(*). (2009).
PKA Has a Critical Role in Synaptic Delivery of GluR1- and GluR4-Containing AMPARs During Initial Stages of Acquisition of In Vitro Classical Conditioning.
Journal of Neurophysiology 101(5): 2539-2549.

The cyclic AMP-dependent protein kinase (PKA) signaling pathway has been shown to be important in mechanisms of synaptic plasticity, although its direct and downstream signaling effects are not well understood. Using an in vitro model of eyeblink classical conditioning, we report that PKA has a critical role in initiating a signaling cascade that results in synaptic delivery of glutamate receptor 1 (GluR1)- and GluR4-containing  -amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) in abducens motor neurons during conditioning. PKA and the Ca<sup>2+</sup>-calmodulin–dependent protein kinases (CaMKs) II and IV are activated early in conditioning and are required for acquisition and expression of conditioned responses (CRs). cAMP-response-element-binding protein (CREB) is also activated early in conditioning but is blocked by coapplication of inhibitors to PKA and the CaMKs, suggesting that CREB is downstream of those signaling cascades. Moreover, evidence suggests that PKA activates extracellular signal-regulated kinase, which is also required for conditioning. Imaging studies after conditioning further indicate that colocalization of GluR1 AMPAR subunits with the synaptic marker synaptophysin requires PKA, but is insensitive to the N-methyl-D-aspartate receptor (NMDAR) inhibitor D,L-AP5. PKA activation also leads to synaptic localization of GluR4 subunits that, unlike GluR1, is dependent on NMDARs and is mediated by CaMKII. Together with previous studies, our findings support a two-stage model of AMPAR synaptic delivery during acquisition of classical conditioning. The first stage involves synaptic incorporation of GluR1-containing AMPARs that serves to activate silent synapses. This allows a second stage of NMDAR- and protein kinase C–dependent delivery of GluR4 AMPAR subunits that supports the acquisition of CRs.

(*) Sanford School of Medicine, University of South Dakota, Vermillion, SD

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Zhou Z, Meng Q(*), Seifert A, Wagener A, Sun Y, Ernst S, Thiel WR. (2009).
Hybrid Mesoporous Materials Containing Covalently Anchored N-phenylthiazolium Salts as Organo Catalysts.
Microporous & Mesoporous Materials 121(1-3): 145-151.

A heterogenized organo catalyst based on an organic–inorganic hybrid material was synthesized by covalently anchoring N-phenylthiazolium salts onto mesoporous silica MCM-41 materials. The results of powder X-ray diffraction and N<sub>2</sub> adsorption show the persistence of the ordered two-dimensional hexagonal mesostructure of the functionalized materials. The integrity of the organic groups in the mesoporous materials is confirmed by solid-state <sup>13</sup>C and <sup>29</sup>Si CP-MAS–NMR spectroscopy. These hybrid mesoporous materials are efficient catalysts for the benzoin condensation and for the cross-coupling of aldehydes with acylimines to yield a-amido ketones. The catalytic activity of the heterogenized organo catalyst can further be enhanced by silylation of the residual Si–OH groups using Me<sub>3</sub>SiCl, due to an increased hydrophobicity of the support’s surface. The recyclability of the catalysts depends on the solvent of reaction: here aprotic and solvents of low polarity turned out to be beneficial.

(*) Department of Chemistry, University of South Dakota, Vermillion, SD

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