722 research outputs found
Metabolism of acetate by human leukocytes
Thesis (Ph.D.)--Boston UniversityThe purpose of this investigation was to study the metabolism of normal human leukocytes. Leukocytes were incubated in vitro with c14-labeled acetate, and the fate of the radioactive carbon was determined by fractionation and analysis of the major, cell components.
Leukocytes were obtained from whole blood by fibrinogen sedimentation and differential centrifugation. Optimal conditions for isolation and incubation of viable cells were developed and assessed using phase microscopy for direct observation of their morphological integrity and by their oxidative metabolism. Control experiments to determine the possible effect of erythrocyte utilization of acetate were run using twice the number of cells ordinarily found in leukocyte suspensions. No utilization of acetate by red blood cells was observed.
Respiration studies were performed using standard Warburg manometry. Otherwise, incubations were carried out in modified Erlenmeyer flasks equipped with center wells for C02 collection and stoppered with serum bottle caps. Flasks were equilibrated and various additions were made to the suspensions using hypodermic needles. Total cells per flask varied from 1 to 5 X 108 with concentrations ranging from 60 to 80 X 106 cells per ml. of suspension. Response of respiration and combustion of acetate were directly proportional to cell number and no detrimental effects due to cell crowding were detectable within this range. [TRUNCATED
Identification of the amino acids of cerebrospinal fluid
Thesis (M.A.)--Boston Universit
Post-synthesis incorporation of Al into germanosilicate ITH zeolites : the influence of treatment conditions on the acidic properties and catalytic behavior in tetrahydropyranylation
M. S. thanks the Czech Science Foundation for support through the project 14-30898P. M. O. acknowledges the Czech Science Foundation for the project 13-17593P. R. E. M. thanks the EPSRC for funding (EP/K025112/1 and EP/L014475/1).Post-synthesis alumination of germanosilicate medium-pore ITH zeolites was shown to be an effective procedure for tuning their acidity. Treatment of ITH zeolites synthesized with different chemical compositions (i.e. Si/Ge = 2.5, 4.4 and 5.8) with aqueous Al(NO3)3 solution led to the formation of strong Brønsted and Lewis acid sites and an increasing fraction of ultramicro- and meso-pores in Ge-rich ITH samples (Si/Ge = 2.5 and 4.4). The concentration of Al incorporated into the framework increases with decreasing Si/Ge ratio of the parent ITH. The increasing temperature of alumination from 80 to 175 °C (HT conditions) resulted in (1) a 1.5-2-fold increase in the concentration of Brønsted acid sites formed and (2) a decreasing fraction of framework Al atoms detectable with base probe molecules (i.e. pyridine, 2,6-di-tert-butylpyridine), i.e. an increased concentration of the "inner" acid sites. The activity of prepared Al-substituted ITH zeolites in tetrahydropyranylation of alcohols is enhanced with increasing amount of accessible acid sites in bulky crystals (e.g. alumination at lower temperature) or with increasing total concentration of acid centres within tiny ITH crystals (e.g. alumination under HT conditions). This trend became more prominent with increasing kinetic diameter of the substrate molecules under investigation (methanol <1-propanol <1-hexanol).PostprintPeer reviewe
Recombinant peptide reverses cryo-capacitation in ram sperm and improves in vitro fertilization
Semen cryopreservation is a very important technique for assisted reproduction; however, the cryopreservation process is harmful because it results in a reduction in sperm motility and viability, and leads to premature signals of capacitation, resulting in lesser than desirable fertility rates after artificial insemination. A fraction of seminal plasma, enriched in proteins that contain type II fibronectin domains (FNII) can reverse molecular indicators of cryo-capacitation. The beneficial effects of these proteins, however, depend on the relative abundance in seminal plasma. To create a safe additive for improving frozen sperm functionality, in the present study there was cloning and expression of a recombinant peptide containing four FNII domains (named TrxA-FNIIx4-His6) and evaluation of its effect after addition to frozen/thawed ram sperm. The cDNA for this protein was expressed in E. coli and after denaturation and re-naturalization of the protein, toxicity and binding capacity were assessed. By fluorescent labelling assessment, there was binding of the protein to the thawed sperm. At the two doses used (0.15 and 0.3 ÎĽM), TrxA-FNIIx4-His6 had the capacity to reverse the molecular indicators of cryo-capacitation as indicated by the reduction on phosphorylated substrates of PKA. Furthermore, the supplementation with this protein resulted in a normal capacitation process as evidenced by the increase in the in vitro fertilization rate when the greatest concentration of the protein was evaluated (73.25 ± 2.95; 40.13 ± 11.82 for 0.3 ÎĽM and control, respectively). There was no effect of protein supplementation on sperm objective motility compared to untreated sperm. In conclusion, the use of TrxA-FNIIx4-His6 is a promising biotechnological approach for cryopreserving ram sperm and maintaining sperm viability.Fil: Ledesma, Alba. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mar del Plata. Instituto de Investigaciones BiolĂłgicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones BiolĂłgicas; ArgentinaFil: Zalazar, Lucia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mar del Plata. Instituto de Investigaciones BiolĂłgicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones BiolĂłgicas; Argentina. Instituto Nacional de TecnologĂa Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: Buchelly ImbachĂ, Francisco Javier. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mar del Plata. Instituto de Investigaciones CientĂficas y TecnolĂłgicas en ElectrĂłnica. Universidad Nacional de Mar del Plata. Facultad de IngenierĂa. Instituto de Investigaciones CientĂficas y TecnolĂłgicas en ElectrĂłnica; ArgentinaFil: Pastore, Juan Ignacio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mar del Plata. Instituto de Investigaciones CientĂficas y TecnolĂłgicas en ElectrĂłnica. Universidad Nacional de Mar del Plata. Facultad de IngenierĂa. Instituto de Investigaciones CientĂficas y TecnolĂłgicas en ElectrĂłnica; ArgentinaFil: Brown, Paula. National Institute of Environmental Health Sciences; Estados UnidosFil: Eddy, Edward Mitch. National Institute of Environmental Health Sciences; Estados UnidosFil: Hozbor, Federico AndrĂ©s. National Institute Of Environmental Health Sciences; . Instituto Nacional de TecnologĂa Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: Cesari, Andreina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mar del Plata. Instituto de Investigaciones BiolĂłgicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones BiolĂłgicas; Argentina. Instituto Nacional de TecnologĂa Agropecuaria. Centro Regional Buenos Aires; Argentin
Change detection in multi-voice music: The role of musical structure, musical training, and task demands.
Volume 06
Introduction from Dean Dr. Charles Ross
Caught Between Folklore and the Cold War: The Americanization of Russian Children\u27s Literature by Kristen Gains
Graphic Design by Amanda Willis
Graphic Design by Holly Backer
Prejudices in Swiss German Accents by Monika Gutierrez
Photography by Cara O\u27Neal
Photography by Sara Nelson
Edmund Tyrone\u27s Long Journey through Night by Sasha Silberman
Photography by Jessica Beardsley
Photography by Jamie Gardner and Edward Peeples
The Republican Razor: The Guillotine as a Symbol of Equality by Jamie Clift
Graphic Design by Matthew Sakach
Genocide: The Lasting Effects of Gender Stratification in Rwanda By Tess Lione and Emily Wilkins
Photography by Kelsey Holt and Jessica Page
Morocco and the 20 February Movement by Charles Vancampen, Gilbert Hall, Jenny Nehrt, Kasey Dye, Amanda Tharp, Jamie Leeawrik, & Ashley McGee
Photography by Emily Poulin
Photography by Michael Kropf
Improving Performance of Arbitrary Precision Arithmetic Using SIMD Assembly Code Instructions by Nick Pastore
Art by Austin Polasky and Morgan Glasco
Art by Laura L. Kahler
The Effects of the Neutral Response Option on the Extremeness of Participant Responses by Melinda L. Edwards and Brandon C. Smith
Graphic Design by Mariah Asbell
Graphic Design by Cabell Edmunds
College Bullying: An Exploratory Analysis by Amelia D. Perry
Photography by Alyssa Hayes
Death-Related Crime: Applying Bryant\u27s Conceptual Paradigm of Thanatological Crime to Military Settings by Irina Boothe
Graphic Design by Perry Bason
Graphic Design by James Earl
An exploration into the impact of exposure to community violence and hope on children's perceptions of well-being: a South African perspective
The study aims to explore the relationship between exposure to community
violence, hope, and well-being. More specifically, the study aims to ascertain whether
hope is a stronger predictor of well-being than exposure to violence. Stratified
random sampling was used to select a sample of 566 adolescents aged 14–17 years,
from both high violence and low violence areas in Cape Town, South Africa. A
questionnaire consisting of Snyder’s Children’s Hope Scale, the Recent Exposure to
Violence Scale and the KIDSCREEN-52 was used. Data analysis techniques included
descriptive statistics, correlations, and multiple regression. A positive, significant
relationship was found between children’s hope and their well-being. Although
exposure to community violence was found to be significantly correlated with wellbeing,
the relationship was negligible.While exposure to community violence and hope
were found to be significant predictors of well-being, hope emerged as a stronger
predictor of child well-being than exposure to community violence.Department of HE and Training approved lis
Metabolic Engineering of Cofactor F420 Production in Mycobacterium smegmatis
Cofactor F420 is a unique electron carrier in a number of microorganisms including Archaea and Mycobacteria. It has been shown that F420 has a direct and important role in archaeal energy metabolism whereas the role of F420 in mycobacterial metabolism has only begun to be uncovered in the last few years. It has been suggested that cofactor F420 has a role in the pathogenesis of M. tuberculosis, the causative agent of tuberculosis. In the absence of a commercial source for F420, M. smegmatis has previously been used to provide this cofactor for studies of the F420-dependent proteins from mycobacterial species. Three proteins have been shown to be involved in the F420 biosynthesis in Mycobacteria and three other proteins have been demonstrated to be involved in F420 metabolism. Here we report the over-expression of all of these proteins in M. smegmatis and testing of their importance for F420 production. The results indicate that co–expression of the F420 biosynthetic proteins can give rise to a much higher F420 production level. This was achieved by designing and preparing a new T7 promoter–based co-expression shuttle vector. A combination of co–expression of the F420 biosynthetic proteins and fine-tuning of the culture media has enabled us to achieve F420 production levels of up to 10 times higher compared with the wild type M. smegmatis strain. The high levels of the F420 produced in this study provide a suitable source of this cofactor for studies of F420-dependent proteins from other microorganisms and for possible biotechnological applications
Event reconstruction for KM3NeT/ORCA using convolutional neural networks
The KM3NeT research infrastructure is currently under construction at two
locations in the Mediterranean Sea. The KM3NeT/ORCA water-Cherenkov neutrino
detector off the French coast will instrument several megatons of seawater with
photosensors. Its main objective is the determination of the neutrino mass
ordering. This work aims at demonstrating the general applicability of deep
convolutional neural networks to neutrino telescopes, using simulated datasets
for the KM3NeT/ORCA detector as an example. To this end, the networks are
employed to achieve reconstruction and classification tasks that constitute an
alternative to the analysis pipeline presented for KM3NeT/ORCA in the KM3NeT
Letter of Intent. They are used to infer event reconstruction estimates for the
energy, the direction, and the interaction point of incident neutrinos. The
spatial distribution of Cherenkov light generated by charged particles induced
in neutrino interactions is classified as shower- or track-like, and the main
background processes associated with the detection of atmospheric neutrinos are
recognized. Performance comparisons to machine-learning classification and
maximum-likelihood reconstruction algorithms previously developed for
KM3NeT/ORCA are provided. It is shown that this application of deep
convolutional neural networks to simulated datasets for a large-volume neutrino
telescope yields competitive reconstruction results and performance
improvements with respect to classical approaches
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