85 research outputs found
Continuous immobilized yeast reactor system for complete beer fermentation using spent grains and corncobs as carrier materials
Despite extensive research carried out in
the last few decades, continuous beer fermentation has not yet managed to outperform the traditional batch technology. An industrial breakthrough in favour of
continuous brewing using immobilized yeast could be expected only on achievement of the following process characteristics: simple design, low investment costs, flexible operation, effective process control and good
product quality. The application of cheap carrier materials of by-product origin could significantly lower the investment costs of continuous fermentation systems.
This work deals with a complete continuous beer fermentation system consisting of a main fermentation reactor (gas-lift) and a maturation reactor (packedbed) containing yeast immobilized on spent grains and
corncobs, respectively. The suitability of cheap carrier materials for long-term continuous brewing was proved. It was found that by fine tuning of process
parameters (residence time, aeration) it was possible to adjust the flavour profile of the final product. Consumers considered the continuously fermented beer to be of a regular quality. Analytical and sensorial profiles of both continuously and batch fermented beers were compared.(Fundação de Amparo a Pesquisa do Estado de São Paulo, Brazil (FAPESPFundação para a Ciência e a Tecnologia (FC
Bilateral Multi-Electrode Neurophysiological Recordings Coupled to Local Pharmacology in Awake Songbirds
Here we describe a protocol for bilateral multielectrode neurophysiological recordings during intracerebral pharmacological manipulations in awake songbirds. This protocol encompasses fitting adult animals with head-posts and recording chambers, and acclimating them to periods of restraint. The adaptation period is followed by bilateral penetrations of multiple electrodes to obtain acute, sensory-driven neurophysiological responses before versus during the application of pharmacological agents of interest. These local manipulations are achieved by simultaneous and restricted drug infusions carried out independently for each hemisphere. We have used this protocol to elucidate how neurotransmitter and neuroendocrine systems shape the auditory and perceptual processing of natural, learned communication signals. However, this protocol can be used to explore the neurochemical basis of sensory processing in other small vertebrates. Representative results and troubleshooting of key steps of this protocol are presented. Following the animal\u27s recovery from head-post and recording chamber implantation surgery, the length of the procedure is 2 d
Effects of two common polymorphisms in the 3' untranslated regions of estrogen receptor β on mRNA stability and translatability
Estrogen signaling is mediated by estrogen receptors (ERs), ERα and ERβ. Aberrant
estrogen signaling is involved in breast cancer development. ERα is one of the key
biomarkers for diagnosis and treatment of breast cancer. Unlike ERα, ERβ is still not
introduced as a marker for diagnosis and established as a target of therapy. Numerous
studies suggest antiproliferative effects of ERβ, however its role remains to be fully
explored. Albeit important, ERα is not a perfect marker, and some aspects of ERα
function are still unclear. This thesis aims to characterize distinct molecular facets of
ER action relevant for breast cancer and provide valuable information for ER-based
diagnosis and treatment design.
In PAPER I, we analyzed the functionality of two common single
nucleotide polymorphisms in the 3’ untranslated regions of ERβ, rs4986938 and
rs928554, which have been extensively investigated for association with various
diseases. A significant difference in allelic expression was observed for rs4986938 in
breast tumor samples from heterozygous individuals. However, no difference in mRNA
stability or translatability between the alleles was observed.
In PAPER II, we provided a more comprehensive understanding of ERβ
function independent of ERα. A global gene expression analysis in a HEK293/ERβ cell
model identified a set of ERβ-regulated genes. Gene Ontology (GO) analysis showed
that they are involved in cell-cell signaling, morphogenesis and cell proliferation.
Moreover, ERβ expression resulted in a significant decrease in cell proliferation.
In PAPER III, using the human breast cancer MCF-7/ERβ cell model,
we demonstrated, for the first time, the binding of ERα/β heterodimers to various
DNA-binding regions in intact chromatin.
In PAPER IV, we investigated a potential cross-talk between estrogen
signaling and DNA methylation by identifying their common target genes in MCF-7
cells. Gene expression profiling identified around 150 genes regulated by both 17β-
estradiol (E2) and a hypomethylating agent 5-aza-2’-deoxycytidine. Based on GO
analysis, CpG island prediction analysis and previously reported ER binding regions,
we selected six genes for further analysis. We identified BTG3 and FHL2 as direct
target genes of both pathways. However, our data did not support a direct molecular
interplay of mediators of estrogen and epigenetic signaling at promoters of regulated
genes.
In PAPER V, we further explored the interactions between estrogen
signaling and DNA methylation, with focus on DNA methyltransferases (DNMT1,
DNMT3a and DNMT3b). E2, via ERα, up-regulated DNMT1 and down-regulated
DNMT3a and DNMT3b mRNA expression. Furthermore, DNMT3b interacted with
ERα. siRNA-mediated DNMT3b depletion increased the expression of two genes,
CDKN1A and FHL2. We proposed that the molecular mechanism underlying
regulation of FHL2 and CDKN1A gene expression involves interplay of DNMT3b and
ERα.
In conclusion, the studies presented in this thesis contribute to the knowledge of ERβ
function, and give additional insight into the cross-talk mechanisms underlying ERα
signaling with ERβ and with DNA methylation pathways
The Advantage of Standing Up to Fight and the Evolution of Habitual Bipedalism in Hominins
BACKGROUND: Many quadrupedal species stand bipedally on their hindlimbs to fight. This posture may provide a performance advantage by allowing the forelimbs to strike an opponent with the range of motion that is intrinsic to high-speed running, jumping, rapid braking and turning; the range of motion over which peak force and power can be produced. METHODOLOGY/PRINCIPAL FINDINGS: To test the hypothesis that bipedal (i.e., orthograde) posture provides a performance advantage when striking with the forelimbs, I measured the force and energy produced when human subjects struck from "quadrupedal" (i.e., pronograde) and bipedal postures. Downward and upward directed striking energy was measured with a custom designed pendulum transducer. Side and forward strikes were measured with a punching bag instrumented with an accelerometer. When subjects struck downward from a bipedal posture the work was 43.70±12.59% (mean ± S.E.) greater than when they struck from a quadrupedal posture. Similarly, 47.49±17.95% more work was produced when subjects struck upward from a bipedal stance compared to a quadrupedal stance. Importantly, subjects did 229.69±44.19% more work in downward than upward directed strikes. During side and forward strikes the force impulses were 30.12±3.68 and 43.04±9.00% greater from a bipedal posture than a quadrupedal posture, respectively. CONCLUSIONS/SIGNIFICANCE: These results indicate that bipedal posture does provide a performance advantage for striking with the forelimbs. The mating systems of great apes are characterized by intense male-male competition in which conflict is resolved through force or the threat of force. Great apes often fight from bipedal posture, striking with both the fore- and hindlimbs. These observations, plus the findings of this study, suggest that sexual selection contributed to the evolution of habitual bipedalism in hominins
Chlamydia trachomatis Infection and Anti-Hsp60 Immunity: The Two Sides of the Coin
Chlamydia trachomatis (CT) infection is one of the most common causes of reproductive tract diseases and infertility. CT-Hsp60 is synthesized during infection and is released in the bloodstream. As a consequence, immune cells will produce anti-CT-Hsp60 antibodies. Hsp60, a ubiquitous and evolutionarily conserved chaperonin, is normally sequestered inside the cell, particularly into mitochondria. However, upon cell stress, as well as during carcinogenesis, the chaperonin becomes exposed on the cell surface (sf-Hsp60) and/or is secreted from cells into the extracellular space and circulation. Reports in the literature on circulating Hsp and anti-Hsp antibodies are in many cases short on details about Hsp60 concentrations, and about the specificity spectra of the antibodies, their titers, and their true, direct, pathogenetic effects. Thus, more studies are still needed to obtain a definitive picture on these matters. Nevertheless, the information already available indicates that the concurrence of persistent CT infection and appearance of sf-Hsp60 can promote an autoimmune aggression towards stressed cells and the development of diseases such as autoimmune arthritis, multiple sclerosis, atherosclerosis, vasculitis, diabetes, and thyroiditis, among others. At the same time, immunocomplexes composed of anti-CT-Hsp60 antibodies and circulating Hsp60 (both CT and human) may form deposits in several anatomical locations, e.g., at the glomerular basal membrane. The opposite side of the coin is that pre-tumor and tumor cells with sf-Hsp60 can be destroyed with participation of the anti-Hsp60 antibody, thus stopping cancer progression before it is even noticed by the patient or physician
A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)
Meeting abstrac
- …