Posted by: kelsijo97 | July 24, 2012

August 2012

Dong, Gaofeng, Callegari, Eduardo, Gloeckner, C. J., Ueffing, M., & Wang, Hongmin. (2012). Mass spectrometric identification of novel posttranslational modification sites in Huntingtin. Proteomics, 12(12), 2060-2064.

Huntington’s disease (HD) is caused by a CAG triplet repeat expansion in exon 1 of the Huntingtin (Htt) gene, encoding an abnormal expanded polyglutamine (polyQ) tract that confers toxicity to the mutant Htt (mHtt) protein. Recent data suggest that posttranslational modifications of mHtt modulate its cytotoxicity. To further understand the cytotoxic mechanisms of mHtt, we have generated HEK293 cell models stably expressing Strep- and FLAG-tagged Htt containing either 19Q (wild-type Htt), 55Q (mHtt), or 94Q (mHtt) repeats. Following tandem affinity purification, the tagged Htt and associated proteins were subjected to tandem mass spectrometry or 2D nano-LC tandem mass spectrometry and several novel modification sites of mHtt containing 55Q or 94Q were identified. These were phosphorylation sites located at Ser431 and Ser432, and ubiquitination site located at Lys444. The two phosphorylation sites were confirmed by Western blot analysis using phosphorylation site-specific antibodies. In addition, prevention of phosphorylation at the two serine sites altered mHtt toxicity and accumulation. These modifications of mHtt may provide novel therapeutic targets for effective treatment of the disorder.

Basic Biomedical Sciences, Vermillion Campus.

 

Gamarra-Luques, Carlos D., Goyeneche, Alicia A., Hapon, Maria B., & Telleria, Carlos M. (2012). Mifepristone prevents repopulation of ovarian cancer cells escaping cisplatin-paclitaxel therapy. Bmc Cancer, 12.

Background: Advanced ovarian cancer is treated with cytoreductive surgery and combination platinum-and taxane-based chemotherapy. Although most patients have acute clinical response to this strategy, the disease ultimately recurs. In this work we questioned whether the synthetic steroid mifepristone, which as monotherapy inhibits the growth of ovarian cancer cells, is capable of preventing repopulation of ovarian cancer cells if given after a round of lethal cisplatin-paclitaxel combination treatment. Methods: We established an in vitro approach wherein ovarian cancer cells with various sensitivities to cisplatin or paclitaxel were exposed to a round of lethal doses of cisplatin for 1 h plus paclitaxel for 3 h. Thereafter, cells were maintained in media with or without mifepristone, and short-and long-term cytotoxicity was assessed. Results: Four days after treatment the lethality of cisplatin-paclitaxel was evidenced by reduced number of cells, increased hypodiploid DNA content, morphological features of apoptosis, DNA fragmentation, and cleavage of caspase-3, and of its downstream substrate PARP. Short-term presence of mifepristone either enhanced or did not modify such acute lethality. Seven days after receiving cisplatin-paclitaxel, cultures showed signs of relapse with escaping colonies that repopulated the plate in a time-dependent manner. Conversely, cultures exposed to cisplatin-paclitaxel followed by mifepristone not only did not display signs of repopulation following initial chemotherapy, but they also had their clonogenic capacity drastically reduced when compared to cells repopulating after cisplatin-paclitaxel. Conclusions: Cytostatic concentrations of mifepristone after exposure to lethal doses of cisplatin and paclitaxel in combination blocks repopulation of remnant cells surviving and escaping the cytotoxic drugs.

Basic Biomedical Sciences, Vermillion Campus.

 

Lu, Lanhai, & Wang, Hongmin. (2012). Transient focal cerebral ischemia upregulates immunoproteasomal subunits. Cellular and molecular neurobiology, 32(6), 965-970.

This study was designed to determine whether focal cerebral ischemia alters the expression of the immunoproteasomal (i-proteasomal) subunits. Transient cerebral ischemia significantly increased the expression of the i-proteasomal subunits, 20S beta1i (LMP2) and beta5i (LMP7) in the parietal cortex and hippocampus. This alteration was associated with a remarkable increase in ubiquitinated proteins. It is likely that the postischemic induction of the i-proteasome plays an important role in coping with the damaged proteins and thus may have an important effect on neuronal survival and death.

Basic Biomedical Sciences, Vermillion Campus.

 

Yuan, Sharleen, & Burrell, Brian D. (2012). Long-term depression of nociceptive synapses by non-nociceptive afferent activity: Role of endocannabinoids, Ca(2+), and calcineurin. Brain Research, 1460, 1-11.

Activity in non-nociceptive afferents is known to produce long-lasting decreases in nociceptive signaling, often referred to as gate control, but the cellular mechanisms mediating this form of neuroplasticity are poorly understood. In the leech, activation of non-nociceptive touch (T) mechanosensory neurons induces a heterosynaptic depression of nociceptive (N) synapses that is endocannabinoid-dependent. This heterosynaptic, endocannabinoid-dependent long-term depression (ecLTD) is observed where the T- and N-cells converge on a common postsynaptic target, in this case the motor neuron that innervates the longitudinal muscles (L-cells) that contributes to a defensive withdrawal reflex. Depression in the nociceptive synapse required both presynaptic and postsynaptic increases in intracellular Ca(2+). Activation of the Ca(2+)-sensitive protein phosphatase calcineurin was also required, but only in the presynaptic neuron. Heterosynaptic ecLTD was unaffected by antagonists for NMDA or metabotropic glutamate receptors, but was blocked by the 5-HT(2) receptor antagonist ritanserin. Depression was also blocked by the CB1 receptor antagonist rimonabant, but this is thought to represent an effect on a TRPV-like receptor. This heterosynaptic, endocannabinoid-dependent modulation of nociceptive synapses represents a novel mechanism for regulating how injury-inducing or painful stimuli are transmitted to the rest of the central nervous system. (C) 2012 Elsevier B.V. All rights reserved.

Basic Biomedical Sciences, Vermillion Campus.

 

Zheng, Zhaoqing, Sabirzhanov, Boris, & Keifer, Joyce. (2012). Two-stage AMPA receptor trafficking in classical conditioning and selective role for glutamate receptor subunit 4 (tGluA4) flop splice variant. Journal of neurophysiology, 108(1), 101-111.

Previously, we proposed a two-stage model for an in vitro neural correlate of eyeblink classical conditioning involving the initial synaptic incorporation of glutamate receptor A1 (GluA1)-containing alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid type receptors (AMPARs) followed by delivery of GluA4-containing AMPARs that support acquisition of conditioned responses. To test specific elements of our model for conditioning, selective knockdown of GluA4 AMPAR subunits was used using small-interfering RNAs (siRNAs). Recently, we sequenced and characterized the GluA4 subunit and its splice variants from pond turtles, Trachemys scripta elegans (tGluA4). Analysis of the relative abundance of mRNA expression by real-time RT-PCR showed that the flip/flop variants of tGluA4, tGluA4c, and a novel truncated variant tGluA4trc1 are major isoforms in the turtle brain. Here, transfection of in vitro brain stem preparations with anti-tGluA4 siRNA suppressed conditioning, tGluA4 mRNA and protein expression, and synaptic delivery of tGluA4-containing AMPARs but not tGluA1 subunits. Significantly, transfection of abducens motor neurons by nerve injections of tGluA4 flop rescue plasmid prior to anti-tGluA4 siRNA application restored conditioning and synaptic incorporation of tGluA4-containing AMPARs. In contrast, treatment with rescue plasmids for tGluA4 flip or tGluA4trc1 failed to rescue conditioning. Finally, treatment with a siRNA directed against GluA1 subunits inhibited conditioning and synaptic delivery of tGluA1-containing AMPARs and importantly, those containing tGluA4. These data strongly support our two-stage model of conditioning and our hypothesis that synaptic incorporation of tGluA4-containing AMPARs underlies the acquisition of in vitro classical conditioning. Furthermore, they suggest that tGluA4 flop may have a critical role in conditioning mechanisms compared with the other tGluA4 splice variants.

Basic Biomedical Sciences, Vermillion Campus.

 

Block, Alyssa J., & Mabee, Paula M. (2012). Development of the mandibular, hyoid arch and gill arch skeleton in the Chinese barb Puntius semifasciolatus: comparisons of ossification sequences among Cypriniformes. Journal of fish biology, 81(1), 54-80.

The morphogenesis and sequence of ossification and chondrification of skeletal elements of the jaws, and hyoid arch and gill arches of Puntius semifasciolatus are described. These data provide a baseline for further studies and enable comparisons with other described cypriniforms. Some general patterns of ossification in the hyoid arch and branchial arches in cypriniforms were notable. First, the overall development is from anterior to posterior, with the exception of the fifth ceratobranchial bone, which ossifies first. Second, where ossification of iterated elements is sequential, it tends to proceed from posterior to anterior, even when more posterior chondrifications are the smallest in the series. Ossification of the ceratobranchial, epibranchial and pharyngobranchial bones tends to proceed from ventral to dorsal. The comparisons revealed small sets of skeletal elements whose ossification sequence appears to be relatively conserved across cyprinid cypriniforms. Several potentially key timing changes in the ossification sequence of the jaws, hyoid arch and gill arches were identified, such as the accelerated timing of ossification of the fifth ceratobranchial bone, which may be unique to cypriniforms. 2012 The Authors. Journal of Fish Biology 2012 The Fisheries Society of the British Isles.

Biology Department

 

Grey, Ericka A., & Mabee, Paula M. (2012). Gill-arch musculature of the quillback carpiodes cyprinus (cypriniformes: catostomidae) with a comparison to cyprinids. Journal of morphology, 273(8), 909-918.

Although the gill-arch osteology of Cypriniformes has been well studied, comparable works on gill-arch musculature are scarce. The focus of previous studies has been on Cyprinidae while other families have received little or no attention. Consequently, generalizations for Cypriniformes have been made from the musculature of cyprinid gill-arches. This study describes the gill-arch musculature of a catostomid, the quillback Carpiodes cyprinus, and demonstrates that there are striking differences in the overall gill-arch musculature of catostomids in comparison to cyprinids, especially in the dorsal gill-arch region. Of the 23 muscles found in the dorsal gill-arch region of cyprinids, only 13 were present in C. cyprinus. Muscles that are absent include adductores 1-5, levator internus 4, levator ceratobranchialis 5 accessorius, retractor ceratobranchialis 5 externus, retractor ceratobranchialis 5 internus, and the retractor ceratobranchialis 5 transversus. In the ventral gill-arch region, the rectus communis is absent. The derived scrolling shape of the dorsal gill-arch skeleton associated with food processing is likely related to the change in musculature. J. Morphol., 2012. 2012 Wiley Periodicals, Inc. Copyright 2012 Wiley Periodicals, Inc.

Biology Department.

 

Kerby, Jacob L., Wehrmann, Anja, & Sih, Andrew. (2012). Impacts of the Insecticide Diazinon on the Behavior of Predatory Fish and Amphibian Prey. Journal of Herpetology, 46(2), 171-176.

We examined the combined effects of sublethal concentrations of the pesticide diazinon and a nonnative predatory fish on the behavior and survival of amphibian prey. A 48-h experiment was performed in tubs containing predatory Western Mosquitofish and diazinon treatments (0, 0.5,1.0 mg/L, and a solvent control). In “no-pesticide” treatments, the presence of fish reduced tadpole survival significantly. In the absence of fish, pesticide presence altered tadpole behavior (reduced refuge use) significantly but did not impact tadpole survival. In the combined presence of both fish and pesticide, tadpoles altered their behavior to become more active, and to hide less. Although these behavioral changes should expose tadpoles to an even higher predation risk, because diazinon also reduced both activity and attack rates by the predatory fish, tadpoles experienced significantly greater survival in treatments with pesticides. Despite the negative impact of diazinon on amphibian antipredator behavior, the stronger impact of diazinon on predator behavior allowed a greater survival rate for the prey. These results demonstrate the importance of studying specific species interactions in understanding the impacts of chemical contaminants on any given species.

Biology Department.

 

Gong, Xiao, Bao, Ying, Qiu, Chao, & Jiang, Chao Yang. (2012). Individual nanostructured materials: fabrication and surface-enhanced Raman scattering. Chemical Communications, 48(56), 7003-7018.

The progress of surface-enhanced Raman scattering (SERS) microscopy and spectroscopy on individual nanostructured materials has been reviewed in this feature article. After a brief introduction on individual nanomaterial SERS, we provide a systematic overview on the fabrication and SERS studies of individual nanoparticulates, nano-junctions and hierarchical nano-aggregate. These SERS-active nanomaterials have great potential in designing novel highly sensitive SERS substrates for the development of SERS-based sensing devices with a broad range of applications.

Chemistry Department.

 

He, H. S., Gurung, A., Si, L. P., & Sykes, Andrew G. (2012). A simple acrylic acid functionalized zinc porphyrin for cost-effective dye-sensitized solar cells. Chemical Communications, 48(61), 7619-7621.

A simple zinc porphyrin with an acrylic acid at the meso position exhibits an energy conversion efficiency of 5.1%, demonstrating its potential for cost-effective dye-sensitized solar cells.

Chemistry Department.

 

Peng, Rui, Zhao, D., Baltrusaitis, J., Wu, Chia Ming, & Koodali, Ranjit T. (2012). Visible light driven photocatalytic evolution of hydrogen from water over CdS encapsulated MCM-48 materials. Rsc Advances, 2(13), 5754-5767.

CdS encapsulated cubic MCM-48 mesoporous photocatalysts were prepared by a post-impregnation method. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption isotherm, UV-visible diffuse reflectance spectroscopy (DRS), FT-IR spectrometry, X-ray photoelectron spectroscopy (XPS), atomic absorption spectroscopy (AAS), and photoluminescence (PL) spectroscopy were employed for the characterization of the CdS incorporated MCM-48 siliceous materials. MCM-48 was loaded with different amounts of CdS. In the current study, all the samples showed photocatalytic activity under visible light (lambda > 400 nm) irradiation for production of hydrogen from splitting of water in the absence of Pt, which is usually used in photocatalytic splitting of water. The photocatalytic activity of the CdS incorporated MCM-48 mesoporous photocatalysts was found to be dependent on the CdS loading and the pore size of MCM-48 siliceous support. The highest solar hydrogen evolution rate by visible light irradiation from the splitting of water was determined to be 1.81 mmol h(-1) gCdS(-1) and the apparent quantum yield was estimated to be 16.6%.

Chemistry Department.

 

Xie, Y., Bao, Ying, Du, J. K., Jiang, Chaoyang, & Qiao, Q. Q. (2012). Understanding of morphology evolution in local aggregates and neighboring regions for organic photovoltaics. Physical Chemistry Chemical Physics, 14(29), 10168-10177.

Fluorescence intensity and its ratio mapping combined with time-dependent optical microscopy and atomic force microscopy (AFM) were used to understand morphology evolution of local aggregates and neighboring regions for organic solar cells. Three solvents with different boiling points including chlorobenzene (CB), 1,3-dichlorobenzene (1,3-DCB) and 1,2-dichlorobenzene (1,2-DCB) were used to engineer morphology. These solvents affected morphology evolution factors such as solvent evaporation rate, formation (e.g., growth rate, size and/or quantity) of (6,6)-phenyl-C61-butric-acid methyl ester (PCBM)-rich aggregates, and packing/ordering of poly(3-hexylthiophene) (P3HT). Three local regions (1, 2 and 3) including microscale aggregates and their surrounding areas were identified to explore the mechanism of morphology evolution. Region 1 was the PCBM-rich aggregates; region 2 was the PCBM-deficient area; and region 3 was the area composed of a relatively normal P3HT/PCBM composite beyond region 2 for each solvent. The intensity of fluorescence spectra decreased as region 1 > region 2 > region 3 in thermally annealed (140 degrees C, 20 min) P3HT/PCBM blend film from each solvent. The highest fluorescence intensity in region 1 was probably caused by the relatively poor phase separation where both PCBM and P3HT formed large isolated domains. The higher fluorescence intensity ratio (720 nm/650 nm) suggested a larger relative amount of PCBM molecules, supported by similar morphologies in fluorescence intensity ratio mapping compared to those in optical images. The fluorescence intensity ratio was with the order of region 1 > region 3 > region 2 in both CB and 1,3-DCB based films, but with region 1 > region 2 > region 3 for the 1,2-DCB based film. The order of effective area taken up by aggregates was CB > 1,3-DCB > 1,2-DCB in annealed (140 degrees C, 10 min) bulk blend films. The final solar cell performance agreed with morphology results. This work is imperative with regards to revealing the mechanism of morphology evolution in local aggregates and surrounding regions for organic photovoltaic films.

Chemistry Department.

 

Bellis, Teri James, Chermak, Gail D., Weihing, Jeffrey, Musiek, Frank E., Nippold, Marilyn, & Schwarz, Ilsa. (2012). Efficacy of Auditory Interventions for Central Auditory Processing Disorder: A Response to Fey et al. (2011). Language, Speech & Hearing Services in Schools, 43(3), 381-386.

Purpose: To provide a commentary on “Auditory Processing Disorder and Auditory/Language Interventions: An Evidence-Based Systematic Review” by Fey et al. (2011). Method: Examination of the conclusions drawn by Fey et al. (2011) in the context of the American Academy of Audiology (2010a, 2010b) and American Speech-Language-Hearing Association (2005a, 2005b, 2005c) guidelines for the diagnosis and treatment of auditory processing disorder, the evidence cited therein, and other pertinent published reports. Results: The review provided by Fey et al. (2011) is limited due to the exclusion of pertinent efficacy studies from their analysis, inclusion of studies that did not employ strictly auditory-based therapies, and lack of well-defined experimental groups in many of the studies cited. Further, the questions posed by their literature review may not have addressed the efficacy of true auditory interventions in the remediation of auditory difficulties in children who have primary deficitsincentral auditory processing. Conclusion: A more comprehensive review than that done by Fey et al. (2011) would have better addressed the fundamental question of the efficacy of direct remediation activities for children with central auditory processing disorder.

Communication Disorders Department.

 

Mcdonald, Eric V., Sweeney, Mark R., & Busacca, Alan J. (2012). Glacial outburst floods and loess sedimentation documented during Oxygen Isotope Stage 4 on the Columbia Plateau, Washington State. Quaternary Science Reviews, 45, 18-30.

Abstract: Stratigraphy and age control of late Pleistocene loess, associated glacial outburst flood deposits and flood-cut unconformities in the Channeled Scabland, Washington State, United States, indicate a significant Cordilleran ice sheet advance during marine Oxygen Isotope Stage 4. Glacial outburst flood deposits from stage 2 (classic Bretz flood deposits, ca 21 to 13 ka) and related features in the Channeled Scabland overlie a widespread layer of loess that contains buried soils and the Mount St. Helens set C tephra (ca 46 ka). This loess in turn overlies deposits of the penultimate episode of giant outburst floods and an unconformity cut by those floods. Regional trends in the thickness, texture, and overall composition of the older loess are strikingly similar to those from the youngest loess, known to be derived from stage 2 flood deposits. We conclude that the older loess also is derived from fine-grained flood deposits. Luminescence ages, tephrochronology, and soil development rates indicate that the bulk of deposition of the older loess occurred during stage 3, following glacial outburst flooding marked by a regional flood-cut unconformity. The apparent cyclical pattern of cold-climate buried soils, flood deposits, and thick loess accumulations demonstrate that sediment supply renewed by flood episodes is a major control on accumulation of loess on glacial timescales.

Earth Sciences Department.

 

Aslam, M., Mahmood, Y., Lio, Y. L., Tsai, T. R., & Khan, M. A. (2012). Double acceptance sampling plans for Burr type XII distribution percentiles under the truncated life test. Journal of the Operational Research Society, 63(7), 1010-1017.

Lio et al (2010a, b) introduced two single acceptance sampling plans (SASPs) for the percentiles of Birnbaum-Saunders and Burr type XII distribution with a truncated censoring scheme. They assured that the acceptance sampling plans for percentiles significantly improve the traditional ones for mean life. In this paper, a double-sampling procedure is developed for Burr type XII distribution percentiles to save sample resource with a truncated censoring scheme. Minimum sample sizes for implementing the proposed double-sampling method are determined under the satisfied levels of consumer’s risk and producer’s risk. Illustrative examples are used to demonstrate the applications of the proposed method. Compared with the SASP, the proposed double-sampling acceptance plan uses less sample resource in average for truncated life testing. Journal of the Operational Research Society (2012) 63, 1010-1017. doi: 10.1057/jors.2011.112 Published online 2 November 2011

Mathematics Department.

 

Van Peursem, Dan, Keller, Christina, Pietrzak, Dale, Wagner, Clare, & Bennett, Clark. (2012). A COMPARISON OF PERFORMANCE AND ATTITUDES BETWEEN STUDENTS ENROLLED IN COLLEGE ALGEBRA VS. QUANTITATIVE LITERACY. Mathematics & Computer Education, 46(2), 107-118.

The article explores the efficacy of a Quantitative Literacy course in preparing students for potential outcomes in traditional College Algebra course. It notes that the establishment of the course is aimed at providing students with alternative to college algebra, and facilitating their understanding on mathematics that they encounter in daily situations. Moreover, it indicates the significance of Quantitative Literacy course in elevating students’ perceptions on the usefulness of mathematics.

Mathematics Department.

 

Hicken, M., Challis, P., Kirshner, R. P., Perumpilly, Gopakumar, & Ripman, B. (2012). CfA4: LIGHT CURVES FOR 94 TYPE Ia SUPERNOVAE. Astrophysical Journal Supplement Series, 200(2).

We present multi-band optical photometry of 94 spectroscopically confirmed Type Ia supernovae (SNe Ia) in the redshift range 0.0055-0.073, obtained between 2006 and 2011. There are a total of 5522 light-curve points. We show that our natural-system SN photometry has a precision of less than or similar to 0.03 mag in BV r’i’, less than or similar to 0.06 mag in u’, and less than or similar to 0.07 mag in U for points brighter than 17.5 mag and estimate that it has a systematic uncertainty of 0.014, 0.010, 0.012, 0.014, 0.046, and 0.073 mag in BV r’i’u’U, respectively. Comparisons of our standard-system photometry with published SN Ia light curves and comparison stars reveal mean agreement across samples in the range of similar to 0.00-0.03 mag. We discuss the recent measurements of our telescope-plus-detector throughput by direct monochromatic illumination by Cramer et al. This technique measures the whole optical path through the telescope, auxiliary optics, filters, and detector under the same conditions used to make SN measurements. Extremely well characterized natural-system passbands (both in wavelength and over time) are crucial for the next generation of SN Ia photometry to reach the 0.01 mag accuracy level. The current sample of low-z SNe Ia is now sufficiently large to remove most of the statistical sampling error from the dark-energy error budget. But pursuing the dark-energy systematic errors by determining highly accurate detector passbands, combining optical and near-infrared (NIR) photometry and spectra, using the nearby sample to illuminate the population properties of SNe Ia, and measuring the local departures from the Hubble flow will benefit from larger, carefully measured nearby samples.

Physics Department.

 

Macmullin, S., Boswell, M., Guiseppe, V. E., Henning, R., Kawano, T., Laroque, B. H., et al. (2012). Partial gamma-ray production cross sections for (n, xn gamma) reactions in natural argon at 1-30 MeV. Physical Review C, 85(6).

Background: Neutron-induced backgrounds are a significant concern for experiments that require extremely low levels of radioactive backgrounds such as direct dark matter searches and neutrinoless double-beta decay experiments. Unmeasured neutron scattering cross sections are often accounted for incorrectly in Monte Carlo simulations. Purpose: The purpose of this article is to determine partial gamma-ray production cross sections for (n, xn gamma) reactions in natural argon for incident neutron energies between 1 and 30 MeV. Methods: The broad-spectrum neutron beam at the Los Alamos Neutron Science Center (LANSCE) was used used for the measurement. Neutron energies were determined using time of flight, and resulting gamma rays from neutron-induced reactions were detected using the GErmanium Array for Neutron Induced Excitations (GEANIE). Results: Partial gamma-ray cross sections were measured for six excited states in Ar-40 and two excited states in Ar-39. Measured (n, xn gamma) cross sections were compared to the TALYS and CoH3 nuclear reaction codes. Conclusions: These new measurements will help to identify potential backgrounds in neutrinoless double-beta decay and dark matter experiments that use argon as a detection medium or shielding. The measurements will also aid in the identification of neutron interactions in these experiments through the detection of gamma rays produced by (n, xn gamma) reactions.

Physics Department.

 

Thiel, C. W., Sun, Y., Macfarlane, R. M., Bottger, T., & Cone, R. L. (2012). Rare-earth-doped LiNbO3 and KTiOPO4 (KTP) for waveguide quantum memories. Journal of Physics B-Atomic Molecular and Optical Physics, 45(12).

Optical waveguides in rare-earth-doped crystals are one of the most promising systems for practical implementations of quantum memory. To further develop these systems, detailed understanding of these materials is required. We report experimental studies of the optical properties and decoherence for Tm3+:LiNbO3, Pr3+:LiNbO3, Er3+:LiNbO3 and Er3+:KTiOPO4 (KTP) bulk crystals for quantum memory applications and discuss potential differences between the properties of the bulk single crystals and optical waveguides. These systems include the rare-earth ions most commonly exploited in quantum memory studies incorporated into two of the most technologically significant waveguide host materials. Photon echo methods were used to study decoherence as a function of temperature, applied magnetic field strength, dopant concentration and excitation wavelength. Decoherence mechanisms were investigated and modelled to interpret the observed behaviour. Spectral hole burning was used to characterize Stark and Zeeman effects. Bulk crystal properties were compared and contrasted to the properties of doped waveguides.

Physics Department.

 

Wang, Guojian, Sun, Yongchen, Yang, Gang, Xiang, Wenchang, Guan, Yutong, Mei, Dongming, et al. (2012). Development of large size high-purity germanium crystal growth. Journal of Crystal Growth, 352(1), 27-30.

Abstract: Growing large diameter (∼15cm) dislocation-free crystals for the GEODM experiment at DUSEL is a challenging task. A crystal of such high purity and large size has never been grown before and the process will require much research and development. In pursuing this goal, we are growing high-purity germanium crystals by the Czochralski method in our laboratory at USD in order to understand the details of the growing process, especially for large diameter crystals. Using a radio frequency (RF) heating method, germanium crystals with two different orientations (along 〈100〉 and 〈111〉) have been grown. The growth characteristics of 〈100〉 crystals have been investigated to understand the impact of the thermal field on the size of the grown crystals. In order to establish the optimal thermal field for growing large high-purity germanium crystals, three different radial thermal fields have been studied. Furthermore, the dislocation density in the grown crystals was measured using an optical microscope and was determined to be about 1×103–4×103/cm2, which falls in the required range for a high-purity germanium detector. X-ray diffraction tests on the surfaces of (100) indicate the grown crystals are of high quality.

Physics Department.

 

Yang, Gang, Wang, Guojian, Xiang, Wenchang, Guan, Yutong, Sun, Yongchen, Mei, Dongming, et al. (2012). Radial and axial impurity distribution in high-purity germanium crystals. Journal of Crystal Growth, 352(1), 43-46.

Abstract: To grow high purity germanium (HPGe) crystals in an underground environment for ultra-low background experiments is being studied. In the present work, HPGe crystals along 〈100〉 direction have been grown by the Czochralski method. In order to investigate the distribution of the impurities as a function of length for a grown crystal, i.e. the axial direction, we fabricated a system to measure the resistivity along the axial direction at both room temperature and liquid nitrogen temperature. The distribution of the impurities along the radial direction was measured with a Hall Effect System. The results show that the carrier concentration in some crystals grown in a hydrogen atmosphere has an impurity level of about 1010/cm3, which meets the requirements of detector-grade crystals.

Physics Department.

 

Huntington, Mark K. (2012). When bed bugs bite. The Journal of family practice, 61(7), 384-388.

Treating bed bug bites is straightforward; helping patients control and even prevent future infestations is another matter. Here’s how you can help.

Sanford School of Medicine, Sioux Falls Campus.

 

Kruer, Michael C., & Boddaert, N. (2012). Neurodegeneration With Brain Iron Accumulation: A Diagnostic Algorithm. Seminars in Pediatric Neurology, 19(2), 67-74.

The diagnosis of neurodegeneration with brain iron accumulation (NBIA) can be challenging, particularly given recent advances in NBIA genetics and clinical nosology. Although atypical cases continue to challenge physicians, by considering clinical features along with relevant neuroimaging findings, the diagnosis of NBIA can be made confidently. In addition, the identification of genetically distinct forms of NBIA allows clinicians to better provide prognostic and family counseling services to families and may have relevance in the near future as clinical trials become available. We describe a heuristic approach to NBIA diagnosis, identify important differential considerations, and demonstrate important neuroimaging features to aid in the diagnosis. Semin Pediatr Neurol 19:67-74 (C) 2012 Elsevier Inc. All rights reserved.

Sanford School of Medicine, Sioux Falls Campus.

 

Morishita, Y., Yoshioka, Y., Satoh, H., Abe, Yasuhiro, Kamada, H., Tsunoda, S., et al. (2012). Distribution and histologic effects of intravenously administered amorphous nanosilica particles in the testes of mice. Biochemical and Biophysical Research Communications, 420(2), 297-301.

Amorphous nanosilica particles (nSP) are being utilized in an increasing number of applications such as medicine, cosmetics, and foods. The reduction of the particle size to the nanoscale not only provides benefits to diverse scientific fields but also poses potential risks. Several reports have described the in vivo and in vitro toxicity of nSP, but few studies have examined their effects on the male reproductive system. The aim of this study was to evaluate the testicular distribution and histologic effects of systemically administered nSP. Mice were injected intravenously with nSP with diameters of 70 nm (nSP70) or conventional microsilica particles with diameters of 300 nm (nSP300) on two consecutive days. The intratesticular distribution of these particles 24 h after the second injection was analyzed by transmission electron microscopy. nSP70 were detected within sertoli cells and spermatocytes, including in the nuclei of spermatocytes. No nSP300 were observed in the testis. Next, mice were injected intravenously with 0.4 or 0.8 mg nSP70 every other day for a total of four administrations. Testes were harvested 48 h and 1 week after the last injection and stained with hematoxylin-eosin for histologic analysis. Histologic findings in the testes of nSP70-treated mice did not differ from those of control mice. Taken together, our results suggest that nSP70 can penetrate the blood-testis barrier and the nuclear membranes of spermatocytes without producing apparent testicular injury. (C) 2012 Elsevier Inc. All rights reserved.

Sanford School of Medicine, Sioux Falls Campus.

 

Ikiugu, Moses, Pollard, N., Cross, Aubrey, Willer, Megan, Everson, Jenna, & Stockland, Jeanie. (2012). Meaning making through occupations and occupational roles: a heuristic study of worker-writer histories. British Journal of Occupational Therapy, 75(6), 289-295.

Introduction: Occupations are recognised in occupational therapy and occupational science literature as vehicles to meaning and wellbeing. Yet, the question of how they are used to create meaning has not been investigated exhaustively. In this study, the researchers explored the life histories of worker-writers in the United Kingdom. These writers considered themselves as representatives of the most numerous but marginalised social class. The researchers considered how the worker-writers derived life meaning from their occupations and occupational roles. Method: Using heuristic research methods, 34 published autobiographies were analysed to elicit themes illuminating how meaning was created by the worker-writers through occupations and occupational roles. Results: Five themes emerged from the analysis. Worker-writers created meaning by engaging in occupations and occupational roles that fostered family life and other meaningful relationships; a sense of control over their lives; meaningful leisure pursuits; a contribution to or connection to greater causes; and a sense of wellbeing. Conclusion: No claims are being made in this study about the generalisability of the findings to clinical practice. However, occupational therapists may consider exploring ways of helping clients engage in occupations reflecting themes that emerged from the study, as a way of helping them to reconstruct their lives following life-changing events or conditions.

School of Health Sciences.

 

Jang, Y. R., Park, N. S., Kim, G., Kwag, K. H., Roh, Soonhee, & Chiriboga, D. A. (2012). The association between self-rated mental health and symptoms of depression in Korean American older adults. Aging & Mental Health, 16(4), 481-485.

Objective: The study examined the association of self-rated mental health (SRMH) with three measures of depressive symptoms (the short form CES-D, GDS-SF, and PHQ-9) in Korean American older adults. Method: The sample consisted of 420 community-dwelling Korean American older adults (M(age) = 71.6, SD = 7.59) in the New York City metropolitan area. Hierarchical regression models of SRMH were estimated with an array of predictors: (a) sociodemographic characteristics, (b) physical health-related variables, and (c) each of the three depressive symptom measures. Results: The three measures of depressive symptoms were interrelated, and each of them made a significant contribution to the multivariate models of SRMH. The amount of variance explained by the short-form CES-D, GDS-SF, and PHQ-9 was 11%, 10%, and 16%, respectively. Conclusion: Findings show a moderately strong linkage between the measures of depressive symptoms and SRMH and invite further research on SRMH in diverse populations.

School of Health Sciences.

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