Posted by: kelsijo97 | August 19, 2013

August 2013

Liu, C., L. Q. Guo, S. Menon, D. Jin, E. Pick, Xuejun Wang, . . . N. Wei. (2013). COP9 Signalosome Subunit Csn8 Is Involved in Maintaining Proper Duration of the G(1) Phase. Journal of Biological Chemistry, 288(28), 20443-20452.

The COP9 signalosome (CSN) is a conserved protein complex known to be involved in developmental processes of eukaryotic organisms. Genetic disruption of a CSN gene causes arrest during early embryonic development in mice. The Csn8 subunit is the smallest and the least conserved subunit, being absent from the CSN complex of several fungal species. Nevertheless, Csn8 is an integral component of the CSN complex in higher eukaryotes, where it is essential for life. By characterizing the mouse embryonic fibroblasts (MEFs) that express Csn8 at a low level, we found that Csn8 plays an important role in maintaining the proper duration of the G(1) phase of the cell cycle. A decreased level of Csn8, either in Csn8 hypomorphic MEFs or following siRNA-mediated knockdown in HeLa cells, accelerated cell growth rate. Csn8 hypomorphic MEFs exhibited a shortened G1 duration and affected expression of G(1) regulators. In contrast to Csn8, down-regulation of Csn5 impaired cell proliferation. Csn5 proteins were found both as a component of the CSN complex and outside of CSN (Csn5-f), and the amount of Csn5-f relative to CSN was increased in the Csn8 hypomorphic cells. We conclude that CSN harbors both positive and negative regulators of the cell cycle and therefore is poised to influence the fate of a cell at the crossroad of cell division, differentiation, and senescence.

Basic Biomedical Sciences, Vermillion Campus.

 

Ambigapathy, Ganesh, Zhaoqing Zheng, Wei Li, & Joyce Keifer. (2013). Identification of a Functionally Distinct Truncated BDNF mRNA Splice Variant and Protein in Trachemys scripta elegans. PloS one, 8(6), e67141.

Brain-derived neurotrophic factor (BDNF) has a diverse functional role and complex pattern of gene expression. Alternative splicing of mRNA transcripts leads to further diversity of mRNAs and protein isoforms. Here, we describe the regulation of BDNF mRNA transcripts in an in vitro model of eyeblink classical conditioning and a unique transcript that forms a functionally distinct truncated BDNF protein isoform. Nine different mRNA transcripts from the BDNF gene of the pond turtle Trachemys scripta elegans (tBDNF) are selectively regulated during classical conditioning: exon I mRNA transcripts show no change, exon II transcripts are downregulated, while exon III transcripts are upregulated. One unique transcript that codes from exon II, tBDNF2a, contains a 40 base pair deletion in the protein coding exon that generates a truncated tBDNF protein. The truncated transcript and protein are expressed in the naive untrained state and are fully repressed during conditioning when full-length mature tBDNF is expressed, thereby having an alternate pattern of expression in conditioning. Truncated BDNF is not restricted to turtles as a truncated mRNA splice variant has been described for the human BDNF gene. Further studies are required to determine the ubiquity of truncated BDNF alternative splice variants across species and the mechanisms of regulation and function of this newly recognized BDNF protein.

Basic Biomedical Sciences, Vermillion Campus.

 

Lei, Daoxiong, Faqian Li, Huabo Su, Jinbao Liu, Ning Wei, & Xuejun Wang. (2013). Hepatic Deficiency of COP9 Signalosome Subunit 8 Induces Ubiquitin-Proteasome System Impairment and Bim-Mediated Apoptosis in Murine Livers. PloS one, 8(7), e67793.

The COP9 signalosome (CSN), an evolutionally highly conserved protein complex composed of 8 unique subunits (CSN1 through CSN8) in higher eukaryotes, is purported to modulate protein degradation mediated by the ubiquitin-proteasome system (UPS) but this has not been demonstrated in a critical mitotic parenchymal organ of vertebrates. Hepatocyte-specific knockout of the Cops8 gene (HS-Csn8KO) was shown to cause massive hepatocyte apoptosis and liver malfunction but the underlying mechanism remains unclear. Here, we report that Csn8/CSN exerts profound impacts on hepatic UPS function and is critical to the stability of the pro-apoptotic protein Bim. Significant decreases in CIS (cytokine-inducible Src homology 2 domain-containing protein), a Bim receptor of a cullin2-based ubiquitin ligase, were found to co-exist with a marked increase of Bim proteins. Csn8 deficiency also significantly decreased 19S proteasome subunit Rpt5 and markedly increased high molecular weight neddylated and ubiquitinated proteins. The use of a surrogate UPS substrate further reveals severe impairment of UPS-mediated proteolysis in HS-Csn8KO livers. Inclusion body-like materials were accumulated in Csn8 deficient hepatocytes. In addition to Bim, massive hepatocyte apoptosis in HS-Csn8KO livers is also associated with elevated expression of other members of the Bcl2 family, including pro-apoptotic Bax as well as anti-apoptotic Bcl2 and Bcl-XL. Increased interaction between Bcl2 and Bim, but not between Bcl2 and Bax, was detected. Hence, it is concluded that hepatic CSN8 deficiency impairs the UPS in the liver and the resultant Bim upregulation likely plays an important role in triggering hepatocyte apoptosis via sequestering Bcl2 away from Bax.

Basic Biomedical Sciences, Vermillion Campus.

 

Ranek, Mark J., Erin J. M. Terpstra, Jie Li, D. A. Kass, & Xuejun Wang. (2013). Protein Kinase G Positively Regulates Proteasome-Mediated Degradation of Misfolded Proteins. Circulation, 128(4), 365-376.

Background Proteasome functional insufficiency is implicated in a large subset of cardiovascular diseases and may play an important role in their pathogenesis. The regulation of proteasome function is poorly understood, hindering the development of effective strategies to improve proteasome function. Methods and Results Protein kinase G (PKG) was manipulated genetically and pharmacologically in cultured cardiomyocytes. Activation of PKG increased proteasome peptidase activities, facilitated proteasome-mediated degradation of surrogate (enhanced green fluorescence protein modified by carboxyl fusion of degron CL1) and bona fide (CryAB(R120G)) misfolded proteins, and attenuated CryAB(R120G) overexpression-induced accumulation of ubiquitinated proteins and cellular injury. PKG inhibition elicited the opposite responses. Differences in the abundance of the key 26S proteasome subunits Rpt6 and 5 between the PKG-manipulated and control groups were not statistically significant, but the isoelectric points were shifted by PKG activation. In transgenic mice expressing a surrogate substrate (GFPdgn), PKG activation by sildenafil increased myocardial proteasome activities and significantly decreased myocardial GFPdgn protein levels. Sildenafil treatment significantly increased myocardial PKG activity and significantly reduced myocardial accumulation of CryAB(R120G), ubiquitin conjugates, and aberrant protein aggregates in mice with CryAB(R120G)-based desmin-related cardiomyopathy. No discernible effect on bona fide native substrates of the ubiquitin-proteasome system was observed from PKG manipulation in vitro or in vivo. Conclusions PKG positively regulates proteasome activities and proteasome-mediated degradation of misfolded proteins, likely through posttranslational modifications to proteasome subunits. This may be a new mechanism underlying the benefit of PKG stimulation in treating cardiac diseases. Stimulation of PKG by measures such as sildenafil administration is potentially a new therapeutic strategy to treat cardiac proteinopathies.

Basic Biomedical Sciences, Vermillion Campus.

 

Weltman, Nathan Y., K. Ojamaa, Olga V. Savinova, Y. F. Chen, Evelyn H. Schlenker, R. Zucchi, . . . A. M. Gerdes. (2013). Restoration of Cardiac Tissue Thyroid Hormone Status in Experimental Hypothyroidism: A Dose-Response Study in Female Rats. Endocrinology, 154(7), 2542-2552.

Thyroid hormones (THs) play a pivotal role in regulating cardiovascular homeostasis. To provide a better understanding of the coordinated processes that govern cardiac TH bioavailability, this study investigated the influence of serum and cardiac TH status on the expression of TH transporters and cytosolic binding proteins in the myocardium. In addition, we sought to determine whether the administration of T-3 (instead of T-4) improves the relationship between THs in serum and cardiac tissue and cardiac function over a short-term treatment period. Adult female Sprague Dawley rats were made hypothyroid by 7 weeks treatment with the antithyroid drug 6-n-propyl-2-thiouracil (PTU). After establishing hypothyroidism, rats were assigned to 1 of 5 graded T-3 dosages plus PTU for a 2-week dose-response experiment. Untreated, age-matched rats served as euthyroid controls. PTU was associated with depressed serum and cardiac tissue T-3 and T-4 levels, arteriolar atrophy, altered TH transporter and cytosolic TH binding protein expression, fetal gene reexpression, and cardiac dysfunction. Short-term administration of T-3 led to a mismatch between serum and cardiac tissue TH levels. Normalization of serum T-3 levels was not associated with restoration of cardiac tissue T-3 levels or cardiac function. In fact, a 3-fold higher T-3 dosage was necessary to normalize cardiac tissue T-3 levels and cardiac function. Importantly, this study provides the first comprehensive data on the relationship between altered TH status (serum and cardiac tissue), cardiac function, and the coordinated in vivo changes in cardiac TH membrane transporters and cytosolic TH binding proteins in altered TH states.

Basic Biomedical Sciences, Vermillion Campus.

 

Brown, Jennifer R., Tyler Miiller, & Jacob L. Kerby. (2013). The interactive effect of an emerging infectious disease and an emerging contaminant on Woodhouse’s toad (Anaxyrus woodhousii) tadpoles. Environmental toxicology and chemistry / SETAC, 32(9), 2003-2008.

Two factors that influence amphibian population declines are infectious diseases and exposure to anthropogenic contaminants. The authors examined an emerging fungal pathogen, Batrachochytrium dendrobatidis (Bd), and its interaction with an emerging contaminant, the antimicrobial triclosan. They first conducted a 2*2*4 factorial study to examine the interactive impacts of dragonfly predator cues, Bd, and triclosan (0g/L, 10g/L, 100g/L, and 1000g/L) on Woodhouse’s toad (Anaxyrus woodhousii) tadpoles. The authors measured the lethal and sublethal impacts of these stressors on tadpoles over 4 wk. All tadpoles in the 100-g/L and 1000-g/L concentrations of triclosan died within 24h of exposure, but tadpoles in the low concentration (10g/L) survived. Tadpoles exposed to only Bd (no triclosan) exhibited a low survival rate (67.5%), whereas those exposed to both 10g/L triclosan and Bd exhibited a high survival rate (91.1%), implying that triclosan inhibits effects of Bd on tadpoles. Batrachochytrium dendrobatidis and predator cue exposure individually increased the developmental rate of the surviving tadpoles, but this effect was absent when these factors were combined with triclosan. In a follow-up study, the authors found Bd growth in culture was significantly inhibited at the 10-g/L concentration of triclosan and completely inhibited at 100g/L. These findings suggest that interactions among multiple stressors can be complex and require examination in conjunction with one another to evaluate actual impacts to aquatic fauna. Environ Toxicol Chem 2013;32:2003-2008. 2013 SETAC. Copyright 2013 SETAC.

Biology Department.

 

Ricci, Lesley, Cliff H. Summers, Earl T. Larson, Donald O’Malley, & Richard H. Melloni. (2013). Development of aggressive phenotypes in zebrafish: interactions of age, experience and social status. Animal Behaviour, 86(2), 245-252.

Aggression is important in the life history of most vertebrate species and influences ecological and social relationships by regulating the dynamics of territoriality, hierarchy, predation and resource utilization. The expression of aggressive behaviour develops as an individual ages and is often shaped by social experience. Even though the heritability of traits that yield dominant–subordinate relationships is high, strong environmental influences also shape the expression of these individual behaviours. In this study we present evidence for the first time of a necessary interplay between factors that generate behavioural phenotypic plasticity in zebrafish. Select presumptively genetic and environmental elements interacted developmentally to produce the behavioural phenotypes necessary for dominant–subordinate relationships in dyads. Aggressive and submissive acts increased in focus and intensity and were correlated with social rank during development, but decreased with duration of the paired interaction.

Biology Department.

 

Welton, L. J., Cameron D. Siler, G. W. Linkem, A. C. Diesmos, M. L. Diesmos, E. Sy, & R. M. Brown. (2013). Dragons in our midst: Phyloforensics of illegally traded Southeast Asian monitor lizards. Biological Conservation, 159, 7-15.

We provide a phylogenetic and population genetic evaluation of the illegal pet and bush meat trade of monitor lizards in the Philippines. We use a molecular dataset assembled from vouchered samples with known localities throughout the country, as a reference for statistical phylogenetic, population genetic, and DNA barcoding analyses of genetic material obtained during a three year survey of the Manila pet trade. Our results provide the first genetic evaluation of a major Southeast Asian city’s illegal trade in monitors and allow us to establish several important conclusions regarding actual, versus reported, origins of Manila’s black market Varanus. Monitor lizards are clearly transported throughout the archipelago for trade; we identified genotypes from areas surrounding Manila, the distinct Bicol faunal subregion of Luzon, Mindanao Island, the Visayan islands, islands of the Romblon Province, the Babuyan islands, and Mindoro Island. Numerous species are involved, including multiple endemic Philippine taxa, the threatened Gray’s monitor (Varanus olivaceus), and the presumably non-Philippine rough-neck monitor (Varanus rudicollis). Our results suggest that traders frequently and deliberately misrepresent the provenance of traded animals, in an apparent effort to increase their perceived market value. (C) 2012 Elsevier Ltd. All rights reserved.

Biology Department.

 

Gallo, Annemarie, & Gopinath Mani. (2013). A stent for co-delivering paclitaxel and nitric oxide from abluminal and luminal surfaces: Preparation, surface characterization, and in vitro drug release studies. Applied Surface Science, 279, 216-232.

Most drug-eluting stents currently available are coated with anti-proliferative drugs on both abluminal (toward blood vessel wall) and luminal (toward lumen) surfaces to prevent neointimal hyperplasia. While the abluminal delivery of anti-proliferative drugs is useful for controlling neointimal hyperplasia, the luminal delivery of such drugs impairs or prevents endothelialization which causes late stent thrombosis. This research is focused on developing a bidirectional dual drug-eluting stent to co-deliver an anti-proliferative agent (paclitaxel – PAT) and an endothelial cell promoting agent (nitric oxide – NO) from abluminal and luminal surfaces of the stent, respectively. Phosphonoacetic acid, a polymer-free drug delivery platform, was initially coated on the stents. Then, the PAT and NO donor drugs were co-coated on the abluminal and luminal stent surfaces, respectively. The co-coating of drugs was collectively confirmed by the surface characterization techniques such as Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), 3D optical surface profilometry, and contact angle goniometry. SEM showed that the integrity of the co-coating of drugs was maintained without delamination or cracks formation occurring during the stent expansion experiments. In vitro drug release studies showed that the PAT was released from the abluminal stent surfaces in a biphasic manner, which is an initial burst followed by a slow and sustained release. The NO was burst released from the luminal stent surfaces. Thus, this study demonstrated the co-delivery of PAT and NO from abluminal and luminal stent surfaces, respectively. The stent developed in this study has potential applications in inhibiting neointimal hyperplasia as well as encouraging luminal endothelialization to prevent late stent thrombosis. (C) 2013 Elsevier B.V. All rights reserved.

Biomedical Engineering, Sioux Falls Campus.

 

Kakade, Sandeep, & Gopinath Mani. (2013). A comparative study of the effects of vitamin C, sirolimus, and paclitaxel on the growth of endothelial and smooth muscle cells for cardiovascular medical device applications. Drug Design Development and Therapy, 7, 529-544.

Antiproliferative drugs such as sirolimus (SIR) and paclitaxel (PAT) are currently released from stents and vascular grafts to inhibit the growth of smooth muscle cells (SMCs), thereby preventing neointimal hyperplasia. However, these drugs delay or impair the growth of endothelial cells (ECs) on implant surfaces causing late thrombosis. Hence, there is a need to use alternative drugs in these implants to encourage the growth of ECs and to inhibit the growth of SMCs. Vitamin C (L-ascorbic acid [L-AA]) is one such drug which has been shown to encourage EC growth and inhibit SMC growth when orally administered or added directly to the cell cultures. In this research, four sets of in vitro cell culture experiments were carried out to compare the effects of L-AA, SIR, and PAT on the growth of ECs and SMCs under similar conditions, and to compare the effects of different doses of L-AA to determine the optimal dose for promoting maximum EC growth and inhibiting SMC growth. The ECs and SMCs treated with different drugs were characterized for their viability and proliferation, and morphology using the quantitative resazurin assay (as well as qualitative fluorescence microscopy characterization) and phase contrast microscopy, respectively, for up to 7 days. Also, the phenotype of ECs was characterized using immunofluorescence microscopy. Both SIR and PAT significantly inhibited the EC growth while L-AA significantly encouraged EC growth even more than that of the controls with no drugs. Also, L-AA significantly inhibited SMC growth although the inhibitory effect was inferior to that of SIR and PAT. The L-AA dosage study demonstrated that 100 mu g and 300 mu g of L-AA showed maximum EC growth after 7 days when compared to other dosages (1 mu g, 500 mu g, and 1000 mu g) of L-AA and controls investigated in this study. Also, the 100 mu g and 300 mu g L-AA doses significantly inhibited the SMC growth. Thus, this study demonstrates that L-AA is a promising drug for potential use in stents and vascular grafts, to promote their endothelialization and inhibit neointimal hyperplasia.

Biomedical Engineering, Sioux Falls Campus.

 

Baride, Aravind, Daniel Engebretson, Mary T. Berry, & P. Stanley May. (2013). Quenching of coumarin emission by CdSe and CdSe/ZnS quantum dots: Implications for fluorescence reporting. Journal of Luminescence, 141, 99-105.

The photoinduced release of highly fluorescent 7-diethylamino coumarin (7DEAC) from CdSe quantum dots (QD) modified with a thiocinnamate ligand (11-mercapto undecyl-E-3-(4-(N,N-diethylamino)-2-hydroxy phenyl) propenoate, [4DEATC]) has been previously described. Coumarin fluorescence was used to ‘report’ the photochemical reaction. The current study quantifies the quenching effect of the QDs on the coumarin emission in this system. A systematic study is presented on the quenching of 7DEAC by CdSe and CdSe/ZnS quantum dots capped with 2-[2-(2-methoxyethoxy)ethoxy] ethanethiol (PEG-thiol). A new method for the functionalization of CdSe and CdSe/ZnS QDs with PEG-thiol was developed, which does not require isolation of the as-synthesized QDs. Stern-Volmer analysis was applied to quantify the effect of the PEG-CdSe and PEG-CdSe/ZnS on 7DEAC emission. The Stern-Volmer constant, K-SV, was shown to be inversely proportional to temperature for quenching by PEG-CdSe, and the fluorescence lifetime of 7DEAC was shown to be independent of PEG-CdSe concentration. Room-temperature K-SV values were similar for the PEG-CdSe and PEG-CdSe/ZnS quenchers. The large magnitude of K-SV, the temperature dependence of K-SV, the lifetime data, and the similarity of K-SV values for the core and core-shell QD quenchers are all consistent with a static quenching mechanism. Assuming a static quenching mechanism, the temperature dependence of the coumarin-QD binding constant, K-b, was used to estimate the Delta H and Delta S for the binding process. (C) 2013 Elsevier B.V. All rights reserved.

Chemistry Department.

 

Baroughi, M. F., D. Dachhepati, U. Gautam, K. Bayat, & P. Stanley May. (2013). Highly tunable self-assembled plasmonic lattices through nanosphere lithography. Optics Letters, 38(12), 2153-2155.

This Letter reports a method to produce two-dimensional self-assembled plasmonic nanopillar (NP) arrays with independent control of the diameter (d), spacing (s), and height (h) of the NPs. A plasmonic lattice was designed and optimized for maximum plasmonic activity at 980 nm using three-dimensional finite-difference time-domain simulations. The optimized lattice with d = 365 nm, s = 410 nm, and h = 70 nm was fabricated utilizing a self-assembled nanosphere lithography approach. Outstanding agreement between the observed and predicted results confirms the validity of the design process and the controllability and repeatability of the fabrication process. The excellent short-range order in the lattice structure suggests that this method can replace the electron-beam lithography approach in a scalable and cost-effective manner. (C) 2013 Optical Society of America

Chemistry Department.

 

Inerbaev, T. M., James D. Hoefelmeyer, & Dmitri S. Kilin. (2013). Photoinduced Charge Transfer from Titania to Surface Doping Site. Journal of Physical Chemistry C, 117(19), 9673-9692.

We evaluate a theoretical model in which Ru is substituting for Ti at the (100) surface of anatase TiO2. Charge transfer from the photoexcited TiO2 substrate to the catalytic site triggers the photocatalytic event (such as water oxidation or reduction half-reaction). We perform ab initio computational modeling of the charge transfer dynamics on the interface of the TiO2 nanorod and catalytic site. A slab of TiO2 represents a fragment of the TiO2 nanorod in the anatase phase. Titanium to ruthenium replacement is performed in a way to match the symmetry of the TiO2 substrate. One molecular layer of adsorbed water is taken into consideration to mimic the experimental conditions. It is found that these adsorbed water molecules saturate dangling surface bonds and affect the electronic properties of systems investigated. The modeling is performed by the reduced density matrix method in the basis of Kohn-Sham orbitals. A nanocatalyst modeled through replacement defect contributes energy levels near the bottom of the conduction band of the TiO2 nanostructure. An exciton in the nanorod is dissipating due to interaction with lattice vibrations, treated through nonadiabatic coupling. The electron relaxes to the conduction band edge and then to the Ru site with a faster rate than the hole relaxes to the Ru site. These results are of importance for an optimal design of nanomaterials for photocatalytic water splitting and solar energy harvesting.

Chemistry Department.

 

Kang, Wonjun, C. S. Spanjers, R. M. Rioux, & James D. Hoefelmeyer. (2013). Synthesis of brookite TiO2 nanorods with isolated Co(II) surface sites and photocatalytic degradation of 5,8-dihydroxy-1,4-naphthoquinone dye. Journal of Materials Chemistry A, 1(26), 7717-7728.

Decomposition of CO2(CO)(8) in the presence of ca. 4 nm x 20 nm oleic acid stabilized brookite TiO2 nanorods was performed according to a prior report in the literature in which Co-TiO2 hybrid nanocrystals had been observed. The hybrid nanocrystals could not be duplicated; however, we report a procedure that consistently led to a mixture of blue Co(II)-TiO2 nanorods and Co precipitate. The Co(II)-TiO2 nanorods have single-site Co(II) ions selectively attached to the TiO2 nanocrystal surface. Transmission electron microscopy and powder X-ray diffraction data show the crystal phase and morphology of the nanorod is unchanged on addition of Co(II) and no new crystal phases or particulate domains are associated with the colloid. A combination of UV-visible, X-ray photoelectron, and X-ray absorption spectroscopic analysis indicates Co(II) sites are present on the surface of the TiO2 nanorods in octahedral and tetrahedral coordination in similar to 1 : 1 ratio. A mechanism is proposed in which the Co-Co bond of the precursor undergoes heterolysis followed by disproportionation of Co(I) to yield Co(II) and Co(0) precipitate. The Co(II)-TiO2 nanorods were shown to exhibit greater activity than TiO2 nanorods in the degradation of 5,8-dihydroxy-1,4-naphthoquinone dye under visible light irradiation.

Chemistry Department.

 

Parayil, Sreenivasan Koliyat, Rhett J. Psota, & Ranjit T. Koodali. (2013). Modulating the textural properties and photocatalytic hydrogen production activity of TiO2 by high temperature supercritical drying. International Journal of Hydrogen Energy, 38(25), 10215-10225.

Abstract: We report a facile method for the synthesis of TiO2 aerogels by a single step high temperature supercritical drying (HTSCD) of sol–gel derived TiO2. The morphological and structural features of the resultant materials were determined by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, Diffuse Reflectance (DR) spectra, and Fourier Transform infra-Red spectroscopy (FT-IR) measurements. The materials exhibited enhanced solar hydrogen production from water using methanol as sacrificial reagent under Ultra-Violet (UV) light in the absence of Pt as a co-catalyst. Among the TiO2 aerogel samples synthesized, TiO2-M-6h evolved 390 μmol g−1 of H2 after 4 h of irradiation, whereas TiO2-M-2h produced 217 μmol g−1 of H2 after 4 h of irradiation under identical conditions, indicating the importance of aging the gels prior to HTSCD step. The enhancement was credited to increase in surface area, and decrease in particle size in TiO2-M-6h as evidenced from N2-sorption and DRS studies respectively. Upon comparison with a room temperature synthesized TiO2-xerogel, the aerogel materials exhibited enhanced hydrogen production. The results validate the superior performance of TiO2 aerogel materials over TiO2 xerogels and indicate the potential of HTSCD method for the preparation of titania aerogels for solar energy applications.

Chemistry Department.

 

Paudel, H. P., D. Dachhepati, K. Bayat, S. S. Mottaghian, P. Stanley May, Cuikiun Lin, . . . M. F. Baroughi. (2013). Design, fabrication, and characterization of a plasmonic upconversion enhancer and its prospects for photovoltaics. Journal of Photonics for Energy, 3, x.

The design, fabrication, and characterization of an upconversion-luminescence enhancer based on a two-dimensional plasmonic crystal are described. Full-wave finite-difference time domain analysis was used for optimizing the geometrical parameters of the plasmonic crystal for maximum plasmon activity, as signified by minimum light reflection. The optimum design produced >20x enhancement in the average electromagnetic field intensity within a one-micron-thick dielectric film over the plasmonic crystal. The optimized plasmonic upconverter was fabricated and used to enhance the upconversion efficiency of sodium yttrium fluoride: 3% erbium, 17% ytterbium nanocrystals dispersed in a poly(methylmethcrylate) matrix. A thin film of the upconversion layer, 105 nm in thickness, was spin-coated on the surface of the plasmonic crystal, as well as on the surfaces of planar gold and bare glass, which were used as reference samples. Compared to the sample with a planar gold back reflector, the plasmonic crystal showed an enhancement of 3.3x for upconversion of 980-nm photons to 655-nm photons. The upconversion enhancement was 25.9x compared to the same coating on bare glass. An absorption model was developed to assess the viability of plasmonically enhanced upconversion for photovoltaic applications. (c) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Chemistry Department.

 

Aslam, M., M. Azam, Y. L. Lio, & C. H. Jun. (2013). Two-Stage Group Acceptance Sampling Plan for Burr Type X Percentiles. Journal of Testing and Evaluation, 41(4), 525-533.

A two-stage group acceptance sampling plan for the percentile of lifetimes which have the Burr type X distribution is discussed under the time truncated life test. The sampling plan parameters for the two-stage sampling plan are determined such that the producer’s risk and consumer’s risk are satisfied simultaneously for the given tester size and experiment time. The advantage of the proposed two-stage sampling plan over the single-stage sampling plan is also discussed. Useful tables are given for practical purpose.

Mathematics Department.

 

Chen, D. G., Y. L. Lio, & Nan Jiang. (2013). Lower Confidence Limits on the Generalized Exponential Distribution Percentiles Under Progressive Type-I Interval Censoring. Communications in Statistics-Simulation and Computation, 42(9), 2106-2117.

In industrial life test and survival analysis, the percentile estimation is always a practical issue with lower confidence bound required for maintenance purpose. Sampling distributions for the maximum likelihood estimators of percentiles are usually unknown. Bootstrap procedures are common ways to estimate the unknown sampling distributions. Five parametric bootstrap procedures are proposed to estimate the confidence lower bounds on maximum likelihood estimators for the generalized exponential (GE) distribution percentiles under progressive type-I interval censoring. An intensive simulation is conducted to evaluate the performances of proposed procedures. Finally, an example of 112 patients with plasma cell myeloma is given for illustration.

Mathematics Department.

 

Garay-Narvaez, L., M. Arim, Jose D. Flores, & R. Ramos-Jiliberto. (2013). The more polluted the environment, the more important biodiversity is for food web stability. Oikos, 122(8), 1247-1253.

Human activities have led to massive influxes of pollutants, degrading the habitat of species and simplifying their biodiversity. However, the interaction between food web complexity, pollution and stability is still poorly understood. In this study we evaluate the effect exerted by accumulable pollutants on the relationship between complexity and stability of food webs. We built model food webs with different levels of richness and connectance, and used a bioenergetic model to project the dynamics of species biomasses. Further, we developed appropriate expressions for the dynamics of bioaccumulated and environmental pollutants. We additionally analyzed attributes of organisms’ and communities as determinants of species persistence (stability). We found that the positive effect of complexity on stability was enhanced as pollutant stress increased. Additionally we showed that the number of basal species and the maximum trophic level shape the complexity-stability relationship in polluted systems, and that in-degree of consumers determines species extinction in polluted environments. Our study indicates that the form of biodiversity and the complexity of interaction networks are essential to understand and project the effects of pollution and other ecosystem threats.

Mathematics Department.

 

Boswell, M. S., S. R. Elliott, D. V. Perepelitsa, M. Devlin, N. Fotiades, R. O. Nelson, . . . V. E. Guiseppe. (2013). Neutron inelastic scattering in natural Cu as a background in neutrinoless double-beta decay experiments. Physical Review C, 87(6).

Background: Experiments designed to study rare processes, such as neutrinoless double-beta decay (0 nu beta beta), are crucial tests for physics beyond the standard model. These experiments rely on reducing the intrinsic radioactive background to unprecedented levels, while adequately shielding the detectors from external sources of radioactivity. Purpose: The purpose of this work is focused on understanding the background rates from neutron interactions in Cu shielding in regions around the Q values of many candidate 0 nu beta beta decay isotopes, as well as providing data for benchmarking Monte Carlo simulations of background events. Methods: Using the broad-spectrum neutron beam at Los Alamos Neutron Science Center, we have measured gamma rays emitted from inelastic neutron scattering on Cu-nat. Results: We extracted the level cross sections from the gamma-production cross section for 46 energy levels in Cu-nat. These level cross sections were compared with the available experimental data, as well as the ENDF/B-VII evaluation for discrete levels. Conclusions: For energy levels above 2 MeV we found significant discrepancies between the suggested level cross sections for both nuclei and our data. We found reasonable agreement between our measurement and the ENDF/B-VII evaluation for the total neutron inelastic cross section in Cu-63. Our measurement of the total neutron inelastic scattering cross section in Cu-65 was 30% lower than the ENDF/B-VII evaluations, which we attribute to unobserved transitions in Cu-65. Furthermore, we found that the implementation of the ENDF/B-VII evaluation in simulations did not properly model the decay properties of the nucleus to the degree necessary for estimating backgrounds in rear-event searches. Finally, we examined the potential implications of our measurements on 0 nu beta beta measurements and found that many of the commonly studied 0 nu beta beta isotopes had Q values below the cutoff for ENDF/B-VII evaluated discrete levels in either Cu nucleus.

Physics Department.

 

Struckman-Johnson, Cindy, & Dave Struckman-Johnson. (2013). Stopping Prison Rape: The Evolution of Standards Recommended by PREA’s National Prison Rape Elimination Commission. Prison Journal, 93(3), 335-354.

The authors, one a past member of the National Prison Rape Elimination Commission (NPREC), review the historic literature on solutions to prison sexual assault. We contend that pressure for humanitarian treatment of inmates as well as other forces internal and external to the prison system brought about the 2003 Prison Rape Elimination Act (PREA) and NPREC. We review the 40 standards to stop prison rape in adult prisons and jails proposed by NPREC in 2009 and compare their scope to solutions from past literature. We recommend that the effectiveness of NPREC standards be evaluated and that the search for solutions continue.

Psychology Department.

Computer Science Department.

 

Getty, Amanda, Attila D. Kovacs, Timea Lengyel-Nelson, Andrew Cardillo, Caitlin Hof, Chun-Hung Chan, & David A. Pearce. (2013). Osmotic Stress Changes the Expression and Subcellular Localization of the Batten Disease Protein CLN3. PloS one, 8(6), e66203.

Juvenile CLN3 disease (formerly known as juvenile neuronal ceroid lipofuscinosis) is a fatal childhood neurodegenerative disorder caused by mutations in the CLN3 gene. CLN3 encodes a putative lysosomal transmembrane protein with unknown function. Previous cell culture studies using CLN3-overexpressing vectors and/or anti-CLN3 antibodies with questionable specificity have also localized CLN3 in cellular structures other than lysosomes. Osmoregulation of the mouse Cln3 mRNA level in kidney cells was recently reported. To clarify the subcellular localization of the CLN3 protein and to investigate if human CLN3 expression and localization is affected by osmotic changes we generated a stably transfected BHK (baby hamster kidney) cell line that expresses a moderate level of myc-tagged human CLN3 under the control of the human ubiquitin C promoter. Hyperosmolarity (800 mOsm), achieved by either NaCl/urea or sucrose, dramatically increased the mRNA and protein levels of CLN3 as determined by quantitative real-time PCR and Western blotting. Under isotonic conditions (300 mOsm), human CLN3 was found in a punctate vesicular pattern surrounding the nucleus with prominent Golgi and lysosomal localizations. CLN3-positive early endosomes, late endosomes and cholesterol/sphingolipid-enriched plasma membrane microdomain caveolae were also observed. Increasing the osmolarity of the culture medium to 800 mOsm extended CLN3 distribution away from the perinuclear region and enhanced the lysosomal localization of CLN3. Our results reveal that CLN3 has multiple subcellular localizations within the cell, which, together with its expression, prominently change following osmotic stress. These data suggest that CLN3 is involved in the response and adaptation to cellular stress.

Sanford School of Medicine, Sioux Falls Campus.

 

Kovacs, Attila D., & David A. Pearce. (2013). Location- and sex-specific differences in weight and motor coordination in two commonly used mouse strains. Scientific reports, 3, 2116.

Several studies have shown that environmental factors can affect the outcome of behavioral experiments, shedding doubts on the inter-laboratory reproducibility of behavioral test results. When our laboratory moved from the University of Rochester, Rochester, NY, to Sanford Research in Sioux Falls, SD, our mouse colony was also transferred and the new environment caused strain-dependent changes in the weight, motor coordination and motor learning capability of mice. Here we report the observed changes for two wild type mouse strains commonly used in transgenic studies, C57BL/6J and 129S6/SvEv, and show that the type of rodent diet is partially responsible for the geographical location-specific differences. We also found sex-specific differences in weight and motor coordination in both mouse strains. Our results show that environmental factors specific to a geographical location can change the body weight, motor coordination and motor learning capability of wild type mice commonly used as controls in transgenic studies.

Sanford School of Medicine, Sioux Falls Campus.

 

Lee, Lance. (2013). Riding the wave of ependymal cilia: Genetic susceptibility to hydrocephalus in primary ciliary dyskinesia. Journal of Neuroscience Research, 91(9), 1117-1132.

Congenital hydrocephalus is a relatively common and debilitating birth defect with several known physiological causes. Dysfunction of motile cilia on the ependymal cells that line the ventricular surface of the brain can result in hydrocephalus by hindering the proper flow of cerebrospinal fluid. As a result, hydrocephalus can be associated with primary ciliary dyskinesia, a rare pediatric syndrome resulting from defects in ciliary and flagellar motility. Although the prevalence of hydrocephalus in primary ciliary dyskinesia patients is low, it is a common hallmark of the disease in mouse models, suggesting that distinct genetic mechanisms underlie the differences in the development and physiology of human and mouse brains. Mouse models of primary ciliary dyskinesia reveal strain-specific differences in the appearance and severity of hydrocephalus, indicating the presence of genetic modifiers segregating in inbred strains. These models may provide valuable insight into the genetic mechanisms that regulate susceptibility to hydrocephalus under the conditions of ependymal ciliary dysfunction. (c) 2013 Wiley Periodicals, Inc.

Sanford School of Medicine, Sioux Falls Campus.

 

Matsumura, J. S., D. Yamanouchi, J. A. Goldstein, C. W. Pollock, M. Bosiers, Greg A. Schultz, . . . K. J. Rocha-Singh. (2013). The United States StuDy for EvalUating EndovasculaR TreAtments of Lesions in the Superficial Femoral Artery and Proximal Popliteal By usIng the Protege EverfLex NitInol STent SYstem II (DURABILITY II). Journal of Vascular Surgery, 58(1), 73-+.

Objective: Angioplasty and stenting are options for revascularization of symptomatic femoral popliteal disease. Although angioplasty alone is effective in short lesions, longer lesions are often treated with stents. Multiple overlapping stents are expensive and may be associated with stent fracture. This trial evaluated the safety and efficacy of a single self-expanding stent up to 20 cm in length in patients with atherosclerotic disease of the superficial femoral artery (SFA) and proximal popliteal artery. Methods: Patients with lesions >4 cm and <18 cm were enrolled in this nonrandomized, prospective, multicenter trial that evaluated the Protege EverFlex Self-Expanding Peripheral Stent System (Covidien, Plymouth, Minn). The study’s primary end points were the 30-day major adverse event rate and duplex ultrasound-assessed patency at 1 year. These were compared with published performance goals. A preplanned analysis was conducted for the primary effectiveness end points at 1 year. Follow-up, including history, ankle-brachial index, patient-reported outcomes, duplex ultrasound assessment, and radiographs, is planned through 3 years. There was core laboratory review of angiograms, ultrasound scans, and plain radiographs. A subgroup of patients was studied with graded treadmill testing. Results: The study enrolled 287 patients (66% male; mean age, 68 years) with stenotic, restenotic, or occluded lesions of the SFA at 44 investigational sites in the United States and Europe. Systemic comorbidities included hypertension (88%), hyperlipidemia (86%), diabetes (43%), and prior SFA intervention (41%). The mean lesion length measured by the core laboratory was 89 mm. The mean normal-to-normal lesion length measured by sites was 110 mm. A total of 303 stents were implanted, and 95% of patients received a single stent. No major adverse events occurred at 30 days. At 1 year, primary outcome of duplex ultrasound stent patency was 67.7% in evaluable patients, and among 1-year secondary outcomes, the mean ankle-brachial index increased by 0.25. Walking Improvement Questionnaire scores improved in pain by 33.7, distance by 37.1, speed by 18.6, and stair climbing by 24.7. The Kaplan-Meier estimate of primary patency was 77.2%, primary assisted patency was 86.9%, and secondary patency was 87.3%. Rutherford clinical category improved in 83.5% of patients. Stent fracture rate was 0.4%. Matched absolute claudication distance was 412 feet greater and was not statistically different in this subgroup of 29 individuals. Conclusions: The results of DURABILITY II (StuDy for EvalUating EndovasculaR TreAtments of Lesions in the Superficial Femoral Artery and Proximal Popliteal By usIng the Protege EverfLex NitInol Stent SYstem II) suggest that a new single stent strategy is safe and effective for the treatment of long lesions of the SFA and proximal popliteal arteries at 1 year.

Sanford School of Medicine, Sioux Falls Campus.

Brown-Rice, Kathleen A., & S. Furr. (2013). Preservice Counselors’ Knowledge of Classmates’ Problems of Professional Competency. Journal of Counseling and Development, 91(2), 224-233.

Master’s-level students (N = 389) in programs accredited by the Council for Accreditation of Counseling and Related Educational Programs were surveyed to determine their knowledge of classmates’ problems of professional competency (PPC). Descriptive statistics were used to analyze the data, and a principal components analysis and Cronbach’s alpha coefficients were applied to reduce and investigate the pattern of correlations among participants’ responses. Findings suggest that the majority of preservice counselors are aware of classmates with PPC and report frustration with faculty for not addressing problematic peers.

School of Education.

Erford, B. T., T. Richards, E. Peacock, Kelly Duncan, H. McGair, B. Muller, . . . C. Y. Chang. (2013). Counseling and Guided Self-Help Outcomes for Clients With Bulimia Nervosa: A Meta-Analysis of Clinical Trials From 1980 to 2010. Journal of Counseling and Development, 91(2), 152-172.

This meta-analysis included 111 clinical trials exploring the effectiveness of counseling/psychotherapy and guided self-help approaches in the treatment of bulimia nervosa. In general, single-group studies supported higher efficacy of counseling/psychotherapy, whereas wait-list, treatment-as-usual, and placebo studies indicated both approaches were equally effective at termination (posttest) and follow-up in altering binging, purging, laxative use, and self-reported bulimia or body dissatisfaction perceptions in nearly all comparisons.

School of Education.

 

Hulac, David M., Garry Wickerd, & Odell Vining. (2013). Allowing Students to Administer Their Own Interventions: An Application of the Self-Administered Folding-In Technique. Rural Special Education Quarterly, 32(2), 31-36.

This study sought to determine the efficacy of a self-administered folding-in technique to help fourth grade students at-risk for math difficulties improve their fluency with multiplication facts. The investigators used a multiple baseline across participants design during a two-phase intervention. While 4 of the 5 students made progress during the first phase of the intervention, all student participants demonstrated significant gains in math fact performance during the second phase of the intervention. During the second phase, the investigators divided the students’ cards into known and unknown piles weekly. This preliminary research suggests interspersal technology may allow students to make progress on fluency tasks with limited adult supervision.

School of Education.

 

Roh, Soonhee, Kyoung Hag Lee, & Dong Pil Yoon. (2013). General Well-Being of Korean Immigrant Elders: The Significance of Religiousness/Spirituality and Social Support. Journal of Social Service Research, 39(4), 483-497.

This study examined how religiousness/spirituality (values/beliefs, private religious practice, religious/spiritual coping, and religious support) and social support are related to the general well-being (positive well-being, general health, vitality, self-control, anxiety, and depression) of 177 Korean immigrant elders (KIEs). Regression analysis revealed a significant association between religious/spiritual coping, religious support, and social support and the general well-being of KIEs. Social workers need to provide spiritually sensitive religious support and coping skills to KIEs to enhance their well-being. A future study needs to use a probability sampling method to confirm generalizable findings concerning the relationship between religiousness/spirituality and general well-being among KIEs.

School of Health Sciences.

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