Dominant loss of responsiveness to sweet and bitter compounds caused by a single mutation in α-gustducin

Biochemical and genetic studies have implicated α-gustducin as a key component in the transduction of both bitter or sweet taste. Yet, α-gustducin-null mice are not completely unresponsive to bitter or sweet compounds. To gain insights into how gustducin mediates responses to bitter and sweet compounds, and to elicit the nature of the gustducin-independent pathways, we generated a dominant-negative form of α-gustducin and expressed it as a transgene from the α-gustducin promoter in both wild-type and α-gustducin-null mice. A single mutation, G352P, introduced into the C-terminal region of α-gustducin critical for receptor interaction rendered the mutant protein unresponsive to activation by taste receptor, but left its other functions intact. In control experiments, expression of wild-type α-gustducin as a transgene in α-gustducin-null mice fully restored responsiveness to bitter and sweet compounds, formally proving that the targeted deletion of the α-gustducin gene caused the taste deficits of the null mice. In contrast, transgenic expression of the G352P mutant did not restore responsiveness of the null mice to either bitter or sweet compounds. Furthermore, in the wild-type background, the mutant transgene inhibited endogenous α-gustducin's interactions with taste receptors, i.e., it acted as a dominant-negative. That the mutant transgene further diminished the residual bitter and sweet taste responsiveness of the α-gustducin-null mice suggests that other guanine nucleotide-binding regulatory proteins expressed in the α-gustducin lineage of taste cells mediate these responses.

Validation of the Item-Attribute Matrix in TIMSS-Mathematics Using Multiple Regression and the LSDM

The purposes of this study were (1) to validate of the item-attribute matrix using two levels of attributes (Level 1 attributes and Level 2 sub-attributes), and (2) through retrofitting the diagnostic models to the mathematics test of the Trends in International Mathematics and Science Study (TIMSS), to evaluate the construct validity of TIMSS mathematics assessment by comparing the results of two assessment booklets. Item data were extracted from Booklets 2 and 3 for the 8th grade in TIMSS 2007, which included a total of 49 mathematics items and every student's response to every item. The study developed three categories of attributes at two levels: content, cognitive process (TIMSS or new), and comprehensive cognitive process (or IT) based on the TIMSS assessment framework, cognitive procedures, and item type. At level one, there were 4 content attributes (number, algebra, geometry, and data and chance), 3 TIMSS process attributes (knowing, applying, and reasoning), and 4 new process attributes (identifying, computing, judging, and reasoning). At level two, the level 1 attributes were further divided into 32 sub-attributes. There was only one level of IT attributes (multiple steps/responses, complexity, and constructed-response). Twelve Q-matrices (4 originally specified, 4 random, and 4 revised) were investigated with eleven Q-matrix models (QM1 ~ QM11) using multiple regression and the least squares distance method (LSDM). Comprehensive analyses indicated that the proposed Q-matrices explained most of the variance in item difficulty (i.e., 64% to 81%). The cognitive process attributes contributed to the item difficulties more than the content attributes, and the IT attributes contributed much more than both the content and process attributes. The new retrofitted process attributes explained the items better than the TIMSS process attributes. Results generated from the level 1 attributes and the level 2 attributes were consistent. Most attributes could be used to recover students' performance, but some attributes' probabilities showed unreasonable patterns. The analysis approaches could not demonstrate if the same construct validity was supported across booklets. The proposed attributes and Q-matrices explained the items of Booklet 2 better than the items of Booklet 3. The specified Q-matrices explained the items better than the random Q-matrices.

Economic and Structural Database for the MEDPRO Project. MEDPRO Report No. 5, May 2013

This report presents the economic and structural database compiled for the MEDPRO project. The database includes governance, infrastructure, finance, environment, energy, agricultural data and development indicators for the 11 southern and eastern Mediterranean countries (SEMCs) studied in the MEDPRO project. The report further details the data and the methods used for the construction of social accounting, bilateral trade, consumption and investment matrices for each of the SEMCs.

An elementary treatise on curves, functions, and forces.

Available on demand as hard copy or computer file from Cornell University Library.

Design Expressions and Dynamic Evaluation of CFST Bridges Subjected to Seismic Hazards

Thesis (Ph.D.)--University of Washington, 2016-06

Genetic effects on alcohol dependence risk: re-evaluating the importance of psychiatric and other heritable risk factors

Background. Genetic influences have been shown to play a major role in determining the risk of alcohol dependence (AD) in both women and men; however, little attention has been directed to identifying the major sources of genetic variation in AD risk. Method. Diagnostic telephone interview data from young adult Australian twin pairs born between 1964 and 1971 were analyzed. Cox regression models were fitted to interview data from a total of 2708 complete twin pairs (690 MZ female, 485 MZ male, 500 DZ female, 384 DZ male, and 649 DZ female/male pairs). Structural equation models were fitted to determine the extent of residual genetic and environmental influences on AD risk while controlling for effects of sociodemographic and psychiatric predictors on risk. Results. Risk of AD was increased in males, in Roman Catholics, in those reporting a history of major depression, social anxiety problems, and conduct disorder, or (in females only) a history of suicide attempt and childhood sexual abuse; but was decreased in those reporting Baptist, Methodist, or Orthodox religion, in those who reported weekly church attendance, and in university-educated males. After allowing for the effects of sociodemographic and psychiatric predictors, 47 % (95 % CI 28-55) of the residual variance in alcoholism risk was attributable to additive genetic effects, 0 % (95 % CI 0-14) to shared environmental factors, and 53 % (95 % CI 45-63) to non-shared environmental influences. Conclusions. Controlling for other risk factors, substantial residual heritability of AD was observed, suggesting that psychiatric and other risk factors play a minor role in the inheritance of AD.

Common E protein determinants for attenuation of glycosaminoglycan-binding variants of Japanese encephalitis and West Nile viruses

Natural isolates and laboratory strains of West Nile virus (WNV) and Japanese encephalitis virus (JEV) were attenuated for neuroinvasiveness in mouse models for flavivirus encephalitis by serial passage in human adenocarcinoma (SW13) cells. The passage variants displayed a small-plaque phenotype, augmented affinity for heparin-Sepharose, and a marked increase in specific infectivity for SW13 cells relative to the respective parental viruses, while the specific infectivity for Vero cells was not altered. Therefore, host cell adaptation of passage variants was most likely a consequence of altered receptor usage for virus attachment-entry with the involvement of cell surface glycosaminoglycans (GAG) in this process. In vivo blood clearance kinetics of the passage variants was markedly faster and viremia was reduced relative to the parental viruses, suggesting that affinity for GAG (ubiquitously present on cell surfaces and extracellular matrices) is a key determinant for the neuroinvasiveness of encephalitic flaviviruses. A difference in pathogenesis between WNV and JEV, which was reflected in more efficient growth in the spleen and liver of the WNV parent and passage variants, accounted for a less pronounced loss of neuroinvasiveness of GAG binding variants of WNV than JEV. Single gain-of-net-positive-charge amino acid changes at E protein residue 49, 138, 306, or 389/390, putatively positioned in two clusters on the virion surface, define molecular determinants for GAG binding and concomitant virulence attenuation that are shared by the JEV serotype flaviviruses.

Changes in neuronal protein 22 expression and cytoskeletal association in the alcohol-dependent and withdrawn rat brain

The action of alcohol on neuronal pathways has been an issue of increasing research focus, with numerous findings contradicting the previously accepted idea that its effect is nonspecific. The human NP22 (hNP22) gene was revealed by its elevated expression in the frontal cortex of the human alcoholic. The sequences of hNP22 and the rat orthologue rNP22 contain a number of domains consistent with those of cytoskeletal-interacting proteins. Localization of rNP22 is restricted to the cytoplasm and processes of neurons and it colocalizes with elements of the microfilament and microtubule matrices including filamentous actin (F-actin), alpha-tubulin, tau, and microtubule-associated protein 2 (MAP2). Withdrawal of Wistar rats after alcohol dependence induced by alcohol vapor produced elevated levels of rNP22 mRNA and protein in the cortex, CA2, and dentate gyrus regions of the hippocampus. In contrast, there was decreased rNP22 expression in the striatum after chronic ethanol exposure. Chronic ethanol exposure did not markedly alter rNP22 colocalization with F-actin, alpha-tubulin, or MAP2, although colocalization at the periphery of the neuronal soma with F-actin was observed only after chronic ethanol exposure and withdrawal. Rat NP22 colocalization with MAP2 was reduced during withdrawal, whereas association with alpha-tubulin and actin was maintained. These findings suggest that the effect of chronic ethanol exposure and withdrawal on rNP22 expression is region selective. Rat NP22 may affect microtubule or microfilament function, thereby regulating the neuroplastic changes associated with the development of alcohol dependence and physical withdrawal.

Biodegradation of naphthalene-2-sulfonic acid present in tannery wastewater by bacterial isolates Arthrobacter sp 2AC and Comamonas sp 4BC

Two bacterial strains, 2AC and 4BC, both capable of utilizing naphthalene-2-sulfonic acid (2-NSA) as a sole source of carbon, were isolated from activated sludges previously exposed to tannery wastewater. Enrichments were carried out in mineral salt medium (MSM) with 2-NSA as the sole carbon source. 16S rDNA sequencing analysis indicated that 2AC is an Arthrobacter sp. and 4BC is a Comamonas sp. Within 33 h, both isolates degraded 100% of 2-NSA in MSM and also 2-NSA in non-sterile tannery wastewater. The yield coefficient was 0.33 g biomass dry weight per gram of 2-NSA. A conceptual model, which describes the aerobic transformation of organic matter, was used for interpreting the biodegradation kinetics of 2-NSA. The half-lives for 2-NSA, at initial concentrations of 100 and 500 mg/l in MSM, ranged from 20 h (2AC) to 26 h (4BC) with lag-phases of 8 h (2AC) and 12 h (4BC). The carbon balance indicates that 75-90% of the initial TOC (total organic carbon) was mineralized, 5-20% remained as DOC (dissolved organic carbon) and 3-10% was biomass carbon. The principal metabolite of 2-NSA biodegradation (in both MSM and tannery wastewater) produced by Comamonas sp. 4BC had a MW of 174 and accounted for the residual DOC (7.0-19.0% of the initial TOC and 66% of the remaining TOC). Three to ten percent of the initial TOC (33% of the remaining TOC) was associated with biomass. The metabolite was not detected when Arthrobacter sp. 2AC was used, and a lower residual DOC and biomass carbon were recorded. This suggests that the two strains may use different catabolic pathways for 2-NSA degradation. The rapid biodegradation of 2-NSA (100 mg/l) added to non-sterile tannery wastewater (total 2-NSA, 105 mg/l) when inoculated with either Arthrobacter 2AC or Comamonas 4BC showed that both strains were able to compete with the indigenous microorganisms and degrade 2-NSA even in the presence of alternate carbon sources (DOC in tannery wastewater = 91 mg/l). The results provide information useful for the rational design of bioreactors for tannery wastewater treatment.

The plasma nutriding of tool and bearing steels

There is some evidence to suggest that nitriding of alloy steels, in particular high speed tool steels, under carefully controlled conditions might sharply increase rolling contact fatigue resistance. However, the subsurface shear stresses developed in aerospace bearing applications tend to occur at depths greater than the usual case depths currently produced by nitriding. Additionally, case development must be limited with certain materials due to case spalling and may not always be sufficient to achieve the current theoretical depths necessary to ensure that peak stresses occur within the case. It was the aim of' this work to establish suitable to overcome this problem by plasma nitriding. To assist this development a study has been made of prior hardening treatment, case development, residual stress and case cracking tendency. M2 in the underhardened, undertempered and fully hardened and tempered conditions all responded similarly to plasma nitriding - maximum surface hardening being achieved by plasma nitriding at 450°C. Case development varied linearly with increasing treatment temperature and also with the square root of the treatment time. Maximum surface hardness of M5O and Tl steels was achieved by plasma nitriding in 15% nitrogen/85% hydrogen and varied logarithmically with atmosphere nitrogen content. The case-cracking contact stress varied linearly with nitriding temperature for M2. Tl and M5O supported higher stresses after nitriding in low nitrogen plasma atmospheres. Unidirectional bending fatigue of M2 has been improved up to three times the strength of the fully hardened and tempered condition by plasma nitriding for 16hrs at 400°C. Fatigue strengths of Tl and M5O have been improved by up to 30% by plasma nitriding for 16hrs at 450°C in a 75% hydrogen/25% nitrogen atmosphere.

Astigmatism and vision:should all astigmatism always be corrected?

As technology and medical devices improve, there is much interest in when and how astigmatism should be corrected with refractive surgery. Astigmatism can be corrected by most forms of refractive surgery, such as using excimer lasers algorithms to ablate the cornea to compensate for the magnitude of refractive error in different meridians. Correction of astigmatism at the time of cataract surgery is well developed and can be achieved through incision placement, relaxing incisions and toric intraocular lens (IOL) implantation. This was less of an issue in the past when there was a lower expectation to be spectacle independent after cataract surgery, in which case the residual refractive error, including astigmatism, could be compensated for with spectacle lenses. The issue of whether presurgical astigmatism should be corrected can be considered separately depending on whether a patient has residual accommodation, and the type of refractive surgery under consideration. We have previously reported on the visual impact of full correction of astigmatism, rather than just correcting the mean spherical equivalent. Correction of astigmatism as low as 1.00 dioptres significantly improves objective and subjective measures of functional vision in prepresbyopes at distance and near.

Optical quality for keratoconic eyes with conventional RGP lens and simulated, customised contact lens corrections:a comparison

Purpose: To compare monochromatic aberrations of keratoconic eyes when uncorrected, corrected with spherically-powered RGP (rigid gas-permeable) contact lenses and corrected using simulations of customised soft contact lenses for different magnitudes of rotation (up to 15°) and translation (up to 1mm) from their ideal position. Methods: The ocular aberrations of examples of mild, moderate and severe keratoconic eyes were measured when uncorrected and when wearing their habitual RGP lenses. Residual aberrations and point-spread functions of each eye were simulated using an ideal, customised soft contact lens (designed to neutralise higher-order aberrations, HOA) were calculated as a function of the angle of rotation of the lens from its ideal orientation, and its horizontal and vertical translation. Results: In agreement with the results of other authors, the RGP lenses markedly reduced both lower-order aberrations and HOA for all three patients. When compared with the RGP lens corrections, the customised lens simulations only provided optical improvements if their movements were constrained within limits which appear to be difficult to achieve with current technologies. Conclusions: At the present time, customised contact lens corrections appear likely to offer, at best, only minor optical improvements over RGP lenses for patients with keratoconus. If made in soft materials, however, these lenses may be preferred by patients in term of comfort. © 2012 The College of Optometrists.

Community college adjunct policies and practices: Incumbents' perspectives and congruence with learning organization tenets

The primary research question was: What is the nature and degree of alignment between the tenets of learning organizations and the policies and practices of a community college concerning adjunct instructors? I investigated the employment experiences of 8 adjunct instructors at a large community college in the Southeastern U.S. to (a) describe and explain the perspectives of the adjuncts, (b) describe and explain my own adjunct employment experience at the same college, (c) determine how the adjunct policies and practices collectively encountered were congruent with or at variance with the tenets of learning organizations, and (d) to use this framework to support recommendations that may help the college achieve more favorable alignment with these tenets. ^ Data on perceived adjunct policies and practices were reduced into 11 categories and, using matrices, were compared with 5 major categories of learning organization tenets. The 5 categories of tenets were: (a) inputs, (b) information flow/communication, (c) employee inclusion/value, (d) teamwork, and (e) facilitation of change. The 11 categories of the college's policies and practices were (a) becoming an adjunct, (b) full-time employment aspirations, (c) salary, (d) benefits, (e) job security and predictability, (f) job satisfaction, (g) respect, (h) support services, (i) professional development, (j) institutional inclusion, and (k) future role of adjuncts. The reflective journal component relied on a 5-year (1995–2000) personal and professional journal maintained by me during employment with the same college as the participants. ^ Findings indicate that the college's adjunct policies and practices were most incongruent with 25 of the 70 learning organization tenets. These incongruencies spanned the 5 categories, although most occurred in the Employee/Inclusion/Value category. Adjunct instructors wanted inclusion, respect, value, trust, and empowerment in decision making processes that affect adjunct policies and practices of the college, but did not perceive this to be a part of the present situation. ^

Dynamic Behavior and Fatigue Life of Highway Bridges Due to Doubling Heavy Vehicles

An increase in the demand for the freight shipping in the United States has been predicted for the near future and Longer Combination Vehicles (LCVs), which can carry more loads in each trip, seem like a good solution for the problem. Currently, utilizing LCVs is not permitted in most states of the US and little research has been conducted on the effects of these heavy vehicles on the roads and bridges. In this research, efforts are made to study these effects by comparing the dynamic and fatigue effects of LCVs with more common trucks. Ten Steel and prestressed concrete bridges with span lengths ranging from 30’ to 140’ are designed and modeled using the grid system in MATLAB. Additionally, three more real bridges including two single span simply supported steel bridges and a three span continuous steel bridge are modeled using the same MATLAB code. The equations of motion of three LCVs as well as eight other trucks are derived and these vehicles are subjected to different road surface conditions and bumps on the roads and the designed and real bridges. By forming the bridge equations of motion using the mass, stiffness and damping matrices and considering the interaction between the truck and the bridge, the differential equations are solved using the ODE solver in MATLAB and the results of the forces in tires as well as the deflections and moments in the bridge members are obtained. The results of this study show that for most of the bridges, LCVs result in the smallest values of Dynamic Amplification Factor (DAF) whereas the Single Unit Trucks cause the highest values of DAF when traveling on the bridges. Also in most cases, the values of DAF are observed to be smaller than the 33% threshold suggested by the design code. Additionally, fatigue analysis of the bridges in this study confirms that by replacing the current truck traffic with higher capacity LCVs, in most cases, the remaining fatigue life of the bridge is only slightly decreased which means that taking advantage of these larger vehicles can be a viable option for decision makers.

Application of self-quenched JH consensus primers for real-time quantitative PCR of IGH gene to minimal residual disease evaluation in multiple myeloma.

Monitoring multiple myeloma patients for relapse requires sensitive methods to measure minimal residual disease and to establish a more precise prognosis. The present study aimed to standardize a real-time quantitative polymerase chain reaction (PCR) test for the IgH gene with a JH consensus self-quenched fluorescence reverse primer and a VDJH or DJH allele-specific sense primer (self-quenched PCR). This method was compared with allele-specific real-time quantitative PCR test for the IgH gene using a TaqMan probe and a JH consensus primer (TaqMan PCR). We studied nine multiple myeloma patients from the Spanish group treated with the MM2000 therapeutic protocol. Self-quenched PCR demonstrated sensitivity of >or=10(-4) or 16 genomes in most cases, efficiency was 1.71 to 2.14, and intra-assay and interassay reproducibilities were 1.18 and 0.75%, respectively. Sensitivity, efficiency, and residual disease detection were similar with both PCR methods. TaqMan PCR failed in one case because of a mutation in the JH primer binding site, and self-quenched PCR worked well in this case. In conclusion, self-quenched PCR is a sensitive and reproducible method for quantifying residual disease in multiple myeloma patients; it yields similar results to TaqMan PCR and may be more effective than the latter when somatic mutations are present in the JH intronic primer binding site.