The Shaping of a New Identity: Continuation of the Transformation Process of People of Color on White University College Campuses Into "White" People of Color

“Our study will show how the pyramidal structure as a permanent feature of every aspect of American society continues to function in the same manner at institutions of higher learning.”

Biogenic calcium phosphate transformation in soils over millennial time scales

Changes in bioavailability of phosphorus (P) during pedogenesis and ecosystem development have been shown for geogenic calcium phosphate (Ca-P). However, very little is known about long-term changes of biogenic Ca-P in soil. Long-term transformation characteristics of biogenic Ca-P were examined using anthropogenic soils along a chronosequence from centennial to millennial time scales. Phosphorus fractionation of Anthrosols resulted in overall consistency with the Walker and Syers model of geogenic Ca-P transformation during pedogenesis. The biogenic Ca-P (e.g., animal and fish bones) disappeared to 3% of total P within the first ca. 2,000 years of soil development. This change concurred with increases in P adsorbed on metal-oxides surfaces, organic P, and occluded P at different pedogenic time. Phosphorus K-edge X-ray absorption near-edge structure (XANES) spectroscopy revealed that the crystalline and therefore thermodynamically most stable biogenic Ca-P was transformed into more soluble forms of Ca-P over time. While crystalline hydroxyapatite (34% of total P) dominated Ca-P species after about 600-1,000 years, beta-tricalcium phosphate increased to 16% of total P after 900-1,100 years, after which both Ca-P species disappeared. Iron-associated P was observable concurrently with Ca-P disappearance. Soluble P and organic P determined by XANES maintained relatively constant (58-65%) across the time scale studied. Disappearance of crystalline biogenic Ca-P on a time scale of a few thousand years appears to be ten times faster than that of geogenic Ca-P.

An Asymmetric Extension for the Family of Elliptical Slash Distributions

In this article, we introduce an asymmetric extension to the univariate slash-elliptical family of distributions studied in Gomez et al. (2007a). This new family results from a scale mixture between the epsilon-skew-symmetric family of distributions and the uniform distribution. A general expression is presented for the density with special cases such as the normal, Cauchy, Student-t, and Pearson type II distributions. Some special properties and moments are also investigated. Results of two real data sets applications are also reported, illustrating the fact that the family introduced can be useful in practice.

Computational tools for comparing asymmetric GARCH models via Bayes factors

In this paper we use Markov chain Monte Carlo (MCMC) methods in order to estimate and compare GARCH models from a Bayesian perspective. We allow for possibly heavy tailed and asymmetric distributions in the error term. We use a general method proposed in the literature to introduce skewness into a continuous unimodal and symmetric distribution. For each model we compute an approximation to the marginal likelihood, based on the MCMC output. From these approximations we compute Bayes factors and posterior model probabilities. (C) 2012 IMACS. Published by Elsevier B.V. All rights reserved.

Genetic transformation of Citrus sinensis with Citrus tristeza virus (CTV) derived sequences and reaction of transgenic lines to CTV infection

Transgenic Citrus sinensis (L.) Osb. plants, cvs. Valencia and Hamlin, expressing Citrus tristeza virus (CTV) derived sequences were obtained by genetic transformation. The gene constructs were pCTV-CP containing the 25 kDa major capsid protein gene (CTV-CP), pCTV-dsCP containing the same CTV-CP gene in an intron-spliced hairpin construct, and pCTV-CS containing a 559 nt conserved region of the CTV genome. The transgenic lines were identified by PCR and the transgene integration was confirmed by Southern blot. Transgene mRNA could be detected in most transgenic lines containing pCTV-CP or pCTV-CS transgene. The mRNA of pCTV-dsCP transgene was almost undetectable, with very light bands in most analyzed plants. The transgene transcription appears to be closely linked to the type of gene construct. The virus challenge assays reveals that all transgenic lines were infected. However, it was possible to identify propagated clones of transgenic plants of both cultivars studied with a low virus titer, with values similar to the non-inoculated plants (negative control). These results suggested that the transgenic plants present some level of resistance to virus replication. The higher number of clones with low virus titer and where mRNA could not be detected or was presented in a very light band was found for pCTV-dsCP-derived transgenic lines.

Lymphocyte transformation assay for C neoformans antigen is not reliable for detecting cellular impairment in patients with Neurocryptococcosis

Background: Cryptococcus neoformans causes meningitis and disseminated infection in healthy individuals, but more commonly in hosts with defective immune responses. Cell-mediated immunity is an important component of the immune response to a great variety of infections, including yeast infections. We aimed to evaluate a specific lymphocyte transformation assay to Cryptococcus neoformans in order to identify immunodeficiency associated to neurocryptococcosis (NCC) as primary cause of the mycosis. Methods: Healthy volunteers, poultry growers, and HIV-seronegative patients with neurocryptococcosis were tested for cellular immune response. Cryptococcal meningitis was diagnosed by India ink staining of cerebrospinal fluid and cryptococcal antigen test (Immunomycol-Inc, SP, Brazil). Isolated peripheral blood mononuclear cells were stimulated with C. neoformans antigen, C. albicans antigen, and pokeweed mitogen. The amount of H-3-thymidine incorporated was assessed, and the results were expressed as stimulation index (SI) and log SI, sensitivity, specificity, and cut-off value (receiver operating characteristics curve). We applied unpaired Student t tests to compare data and considered significant differences for p<0.05. Results: The lymphotoxin alpha showed a low capacity with all the stimuli for classifying patients as responders and non-responders. Lymphotoxin alpha stimulated by heated-killed antigen from patients with neurocryptococcosis was not affected by TCD4+ cell count, and the intensity of response did not correlate with the clinical evolution of neurocryptococcosis. Conclusion: Response to lymphocyte transformation assay should be analyzed based on a normal range and using more than one stimulator. The use of a cut-off value to classify patients with neurocryptococcosis is inadequate. Statistical analysis should be based on the log transformation of SI. A more purified antigen for evaluating specific response to C. neoformans is needed.

A log-Birnbaum-Saunders regression model with asymmetric errors

This paper introduces a skewed log-Birnbaum-Saunders regression model based on the skewed sinh-normal distribution proposed by Leiva et al. [A skewed sinh-normal distribution and its properties and application to air pollution, Comm. Statist. Theory Methods 39 (2010), pp. 426-443]. Some influence methods, such as the local influence and generalized leverage, are presented. Additionally, we derived the normal curvatures of local influence under some perturbation schemes. An empirical application to a real data set is presented in order to illustrate the usefulness of the proposed model.

Genetic transformation of three sweet orange cultivars from explants of adult plants

The difficulty in adult tissue genetic transformation in woody species is still an obstacle to be overcome, including in most sweet orange cultivars of the Brazilian citrus industry. This work reports that, after in vitro culture adjustments, transgenic adventitious buds of 'Hamlin', 'Pra', and 'Valencia' sweet oranges (Citrus sinensis L. Osbeck) were recovered using adult material as explant source, in genetic transformation experiments via Agrobacterium tumefaciens. The transgenic buds were identified by the GUS histochemical analysis and confirmed by PCR analysis, which indicated the presence of an amplified fragment of 817 bp corresponding to the uidA gene sequence. The efficiencies of genetic transformation for 'Hamlin', 'Pra', and 'Valencia' sweet orange cultivars were 2.5, 1.4, and 3.7%, respectively. Media supplemented with auxins and cytokinins during co-culture, and media with high concentrations of cytokinins (3 mg L-1) during transgenic selection led to the transformation and, consequently, the regeneration of adequate number of adventitious buds for the three cultivars. The use of sonication during the explant disinfection was not effective to reduce endophytic contamination and reduced transformation efficiency.

BCL2A1a Over-Expression in Murine Hematopoietic Stem and Progenitor Cells Decreases Apoptosis and Results in Hematopoietic Transformation

We previously reported the development of a lethal myeloid sarcoma in a non-human primate model utilizing retroviral vectors to genetically modify hematopoietic stem and progenitor cells. This leukemia was characterized by insertion of the vector provirus into the BCL2A1 gene, with resultant BCL2A1 over-expression. There is little information on the role of this anti-apoptotic member of the BCL2 family in hematopoiesis or leukemia induction. Therefore we studied the impact of Bcl2a1a lentiviral over-expression on murine hematopoietic stem and progenitor cells. We demonstrated the anti-apoptotic function of this protein in hematopoietic cells, but did not detect any impact of Bcl2a1a on in vitro cell growth or cell cycle kinetics. In vivo, we showed a higher propensity of HSCs over-expressing Bcl2a1a to engraft and contribute to hematopoiesis. Mice over-expressing Bcl2a1a in the hematologic compartment eventually developed an aggressive malignant disease characterized as a leukemia/lymphoma of B-cell origin. Secondary transplants carried out to investigate the primitive origin of the disease revealed the leukemia was transplantable. Thus, Bcl2a1 should be considered as a protooncogene with a potential role in both lymphoid and myeloid leukemogenesis, and a concerning site for insertional activation by integrating retroviral vectors utilized in hematopoietic stem cell gene therapy.

alpha,beta-Unsaturated Diazoketones as Platforms in the Asymmetric Synthesis of Hydroxylated Alkaloids. Total Synthesis of 1-Deoxy-8,8a-diepicastanospermine and 1,6-Dideoxyepicastanospermine and Formal Synthesis of Pumiliotoxin 251D

A versatile and concise approach for the stereoselective synthesis of mono-, di-, and trihydroxylated indolizidines is presented in four to six steps from Cbz-prolinal and a diazophosphonate. The key steps involved a Wolff rearrangement, followed by a stereoselective dihydroxylation/epoxidation reaction, from an alpha,beta-unsaturated diazoketone. The strategy also permits extension to the synthesis of many natural hydroxylated indolizidine alkaloids as demonstrated in the formal synthesis of pumiliotoxin 251D.

Fungal Transformation and Schistosomicidal Effects of Pimaradienoic Acid

The schistosomicidal effects of pimaradienoic acid (PA) and two derivatives, obtained by fungal transformation in the presence of Aspergillus ochraceus, were investigated. PA was the only compound with antischistosomal activity among the three diterpenes studied, with the ability to significantly reduce the viability of the parasites at concentrations ranging from 25 to 100 mu M. PA also promoted morphological alterations of the tegument of Schistosoma mansoni, separated all the worm couples, and affected the production and development of eggs. Moreover, this compound was devoid of toxicity toward human fibroblasts. In a preliminary in vivo experiment, PA at a dose of 100 mg/kg significantly diminished the number of parasites in infected Balb/c mice. Taken together, these results show that PA may be potentially employed in the discovery of novel schistosomicidal agents, and that diterpenes are an important class of natural compounds for the investigation of agents capable of fighting the parasite responsible for human schistosomiasis.

Microbial transformation of the sesquiterpene lactone tagitinin C by the fungus Aspergillus terreus

The biotransformation of the sesquiterpene lactone tagitinin C by the fungus Aspergillus terreus MT 5.3 yielded a rare derivative that was elucidated by spectrometric methods. The fungus led to the formation of a different product through an unusual epoxidation reaction between C4 and C5, formation of a C3,C10 ether bridge, and a methoxylation of the C1 of tagitinin C. The chemical structure of the product, namely 1 beta-methoxy-3 alpha-hydroxy-3,10 beta-4,5 alpha-diepoxy-8 beta-isobutyroyloxygermacr-11(13)-en-6 alpha,12-olide, is the same as that of a derivative that was recently isolated from the flowers of a Brazilian population of Mexican sunflower (Tithonia diversifolia), which is the source of the substrate tagitinin C. The in vitro cytotoxic activity of the substrate and the biotransformed product were evaluated in HL-60 cells using an MTT assay, and both compounds were found to be cytotoxic. We show that soil fungi may be useful in the biotransformation of sesquiterpene lactones, thereby leading to unusual changes in their chemical structures that may preserve or alter their biological activities, and may also mimic plant biosynthetic pathways for production of secondary metabolites.

Width of buccal and posterior corridors: differences between cases treated with asymmetric and symmetric extractions

OBJECTIVE: To verify if there is difference in the buccal and posterior corridor width in cases treated with extraction of one and four premolars. METHODS: Through posed smile photographs of 23 Class II patients, subdivision, treated with extraction of one premolar and 25 Class I and Class II patients, subdivision, treated with extraction of four premolars, the percentage of buccal and posterior corridor width was calculated. The two protocols of extractions were compared regarding the buccal and posterior corridor width by independent t tests. RESULTS: There was no statistically significant difference on the buccal and posterior corridor widths between patients treated with symmetric and asymmetric extraction. CONCLUSION: The buccal and posterior corridor did not differ between the evaluated protocols of extractions.

Incorporating IT & AT Convergence into Lean Thinking/Six Sigma via the Smarter Operation Transformation (SOT) Methodology

The growing demands for industrial products are imposing an increasingly intense level of competitiveness on the industrial operations. In the meantime, the convergence of information technology (IT) and automation technology (AT) is showing itself to be a tool of great potential for the modernization and improvement of industrial plants. However, for this technology fully to achieve its potential, several obstacles need to be overcome, including the demonstration of the reasoning behind estimations of benefits, investments and risks used to plan the implementation of corporative technology solutions. This article focuses on the evolutionary development of planning and adopting processes of IT & AT convergence. It proposes the incorporation of IT & AT convergence practices into Lean Thinking/Six Sigma, via the method used for planning the convergence of technological activities, known as the Smarter Operation Transformation (SOT) methodology. This article illustrates the SOT methodology through its application in a Brazilian company in the sector of consumer goods. In this application, it is shown that with IT & AT convergence is possible with low investment, in order to reduce the risk of not achieving the goals of key indicators.

Nonlocal asymmetric exclusion process on a ring and conformal invariance

We present a one-dimensional nonlocal hopping model with exclusion on a ring. The model is related to the Raise and Peel growth model. A nonnegative parameter u controls the ratio of the local backwards and nonlocal forwards hopping rates. The phase diagram, and consequently the values of the current, depend on u and the density of particles. In the special case of half-lling and u = 1 the system is conformal invariant and an exact value of the current for any size L of the system is conjectured and checked for large lattice sizes in Monte Carlo simulations. For u > 1 the current has a non-analytic dependence on the density when the latter approaches the half-lling value.