Growth factor in f(T) gravity

We derive the evolution equation of growth factor for the matter over-dense perturbation in $f(T)$ gravity. For instance, we investigate its behavior in power law model at small redshift and compare it to the prediction of $\Lambda$CDM and dark energy with the same equation of state in the framework of Einstein general relativity. We find that the perturbation in $f(T)$ gravity grows slower than that in Einstein general relativity if \p f/\p T>0 due to the effectively weakened gravity.Comment: 15 pages,1 figure; v2,typos corrected; v3, discussions added, accepted by JCA

E.Coli derived camelid antibodies as a sensor for P53 in saliva

Oral squamous cell carcinoma (OSCC) is a malignant tumor with 640,000 new cases annually in the world [1]. Saliva testing is non-invasive procedure that is capable to detect potential biomarkers for OSCC. It was shown that elevated level of p53 protein was identified in OSCC patients at different stages of the disease (ibid). Camelid antibodies containing only variable regions, nanobodies (VHH) and single-chain variable regions (scFv) with VH and VL, are becoming popular in many biological studies including diagnostic applications. It was identified that VL region alone showed higher affinity to p53 than VHH, and dimerization of VL region with another one increases the affinity up to 10 folds [2]. Camelid antibodies have similar affinity to its substrate as human antibodies and can be conjugated to other proteins without functional lose. They can be expressed and secreted in many organisms including E.Coli in high amount, which reduces the cost of antibodies production. Thus, the aim of this project is to design a biosensor, based on available sequence of antibodies, to detect p53 in saliva samples for OSCC diagnosis

Resolution of dark matter problem in f(T) gravity

In this paper, we attempt to resolve the dark matter problem in f(T) gravity. Specifically, from our model we successfully obtain the flat rotation curves of galaxies containing dark matter. Further, we obtain the density profile of dark matter in galaxies. Comparison of our analytical results shows that our torsion-based toy model for dark matter is in good agreement with empirical data-based models. It shows that we can address the dark matter as an effect of torsion of the space.Comment: 14 pages, 3 figure

QCD ghost f(T)-gravity model

Within the framework of modified teleparallel gravity, we reconstruct a f(T) model corresponding to the QCD ghost dark energy scenario. For a spatially flat FRW universe containing only the pressureless matter, we obtain the time evolution of the torsion scalar T (or the Hubble parameter). Then, we calculate the effective torsion equation of state parameter of the QCD ghost f(T)-gravity model as well as the deceleration parameter of the universe. Furthermore, we fit the model parameters by using the latest observational data including SNeIa, CMB and BAO data. We also check the viability of our model using a cosmographic analysis approach. Moreover, we investigate the validity of the generalized second law (GSL) of gravitational thermodynamics for our model. Finally, we point out the growth rate of matter density perturbation. We conclude that in QCD ghost f(T)-gravity model, the universe begins a matter dominated phase and approaches a de Sitter regime at late times, as expected. Also this model is consistent with current data, passes the cosmographic test, satisfies the GSL and fits the data of the growth factor well as the LCDM model.Comment: 19 pages, 9 figures, 2 tables. arXiv admin note: substantial text overlap with arXiv:1111.726

Identification of a Novel Class of Farnesylation Targets by Structure-Based Modeling of Binding Specificity

Farnesylation is an important post-translational modification catalyzed by farnesyltransferase (FTase). Until recently it was believed that a C-terminal CaaX motif is required for farnesylation, but recent experiments have revealed larger substrate diversity. In this study, we propose a general structural modeling scheme to account for peptide binding specificity and recapitulate the experimentally derived selectivity profile of FTase in vitro. In addition to highly accurate recovery of known FTase targets, we also identify a range of novel potential targets in the human genome, including a new substrate class with an acidic C-terminal residue (CxxD/E). In vitro experiments verified farnesylation of 26/29 tested peptides, including both novel human targets, as well as peptides predicted to tightly bind FTase. This study extends the putative range of biological farnesylation substrates. Moreover, it suggests that the ability of a peptide to bind FTase is a main determinant for the farnesylation reaction. Finally, simple adaptation of our approach can contribute to more accurate and complete elucidation of peptide-mediated interactions and modifications in the cell

Rho GTPases as therapeutic targets in Alzheimer’s disease

The progress we have made in understanding Alzheimer’s disease (AD) pathogenesis has led to the identification of several novel pathways and potential therapeutic targets. Rho GTPases have been implicated as critical components in AD pathogenesis, but their various functions and interactions make understanding their complex signaling challenging to study. Recent advancements in both the field of AD and Rho GTPase drug development provide novel tools for the elucidation of Rho GTPases as a viable target for AD. Herein, we summarize the fluctuating activity of Rho GTPases in various stages of AD pathogenesis and in several in vitro and in vivo AD models. We also review the current pharmacological tools such as NSAIDs, RhoA/ROCK, Rac1, and Cdc42 inhibitors used to target Rho GTPases and their use in AD-related studies. Finally, we summarize the behavioral modifications following Rho GTPase modulation in several AD mouse models. As key regulators of several AD-related signals, Rho GTPases have been studied as targets in AD. However, a consensus has yet to be reached regarding the stage at which targeting Rho GTPases would be the most beneficial. The studies discussed herein emphasize the critical role of Rho GTPases and the benefits of their modulation in AD

Generalized Second Law of Thermodynamics in f(T)f(T) Gravity with Entropy Corrections

We study the generalized second law (GSL) of thermodynamics in $f(T)$ cosmology. We consider the universe as a closed bounded system filled with $n$ component fluids in the thermal equilibrium with the cosmological boundary. We use two different cosmic horizons: the future event horizon and the apparent horizon. We show the conditions under which the GSL will be valid in specific scenarios of the quintessence and the phantom energy dominated eras. Further we associate two different entropies with the cosmological horizons: with a logarithmic correction term and a power-law correction term. We also find the conditions for the GSL to be satisfied or violated by imposing constraints on model parameters.Comment: 17 pages, no figure, title changed, version accepted for publication in Astrophysics and Space Scienc

The Coupling of Alternative Splicing and Nonsense-Mediated mRNA Decay

Most human genes exhibit alternative splicing, but not all alternatively spliced transcripts produce functional proteins. Computational and experimental results indicate that a substantial fraction of alternative splicing events in humans result in mRNA isoforms that harbor a premature termination codon (PTC). These transcripts are predicted to be degraded by the nonsense-mediated mRNA decay (NMD) pathway. One explanation for the abundance of PTC-containing isoforms is that they represent splicing errors that are identified and degraded by the NMD pathway. Another potential explanation for this startling observation is that cells may link alternative splicing and NMD to regulate the abundance of mRNA transcripts. This mechanism, which we call "Regulated Unproductive Splicing and Translation" (RUST), has been experimentally shown to regulate expression of a wide variety of genes in many organisms from yeast to human. It is frequently employed for autoregulation of proteins that affect the splicing process itself. Thus, alternative splicing and NMD act together to play an important role in regulating gene expression

Вплив ліпосомальної трансфекції гена аполіпопротеїна E3 на динаміку неврологічного та когнітивного дефіциту при черепно-мозковій травмі в експерименті

The aim of study was to estimate gene therapy influence, that promotes synthesis induction of 3 apolipoprotein E (apoE3) in damaged brain tissue, on motor and memory dysfunction and learning disorders after experimental traumatic brain injury (TBI). Heavy TBI in rats was inflicted under overall anesthesia by free falling from1.5 mof load weighting450 g. The mixture of DOTAP liposome and 25 µg of plasmid vector pCMV•SPORT6 with cDNA of APOE3 gene was infused intraventricularly using ALZET osmotic pump. Posttraumatic neurologic deficits was estimated according to the scale of motor dysfunction at the first day of experiment before TBI infliction and from 1st to 7th day after trauma. Cognitive functions (spatial memory and learning) were tested in Morris water maze during 7–10 days after injury. The obtained results testified that cationic liposome-mediated APOE3 gene transfer caused quicker regress of neurologic and cognitive disorders after experimental TBI.Цель работы — изучение влияния генной терапии, способствующей индукции синтеза изоформы 3 аполипопротеина Е (АРОЕ3) в ткани травмированного головного мозга, на выраженность двигательных расстройств и нарушение памяти и обучаемости при черепно-мозгововй травме (ЧМТ) в эксперименте. Тяжелую ЧМТ наносили крысам под общей анестезией путем свободного падения груза массой450 гс высоты1,5 м. Внутрижелудочковую инфузию катионных липосом DOTAP, несущих 25 мкг плазмидного вектора pCMV•SPORT6 с кДНК гена APOE3, осуществляли с помощью осмотических помп ALZET. Выраженность посттравматического неврологического дефицита оценивали по шкале двигательной дисфункции в день начала эксперимента, до нанесения травмы и с 1-х по 7-е сутки после травмы. Когнитивные функции (пространственная память и обучаемость) оценивали в водном лабиринте Морриса в течение 7–10 сут после травмы. Результаты исследования свидетельствуют, что индукция синтеза в нервной ткани изоформы 3 apoE с помощью плазмидного вектора, доставляемого в клетки с помощью катионных липосом, способствует более быстрому регрессу неврологических и когнитивных нарушений при экспериментальной ЧМТ.Мета роботи — вивчення впливу генної терапії, що спричиняє індукцію синтезу ізоформи 3 аполіпопротеїну Е (АРОЕ3) в тканині травмованого головного мозку, на вираженість рухових розладів і порушень пам’яті та здатності до навчання при черепно-мозковій травмі (ЧМТ) в експерименті. Тяжку ЧМТ завдавали щурам під загальною анестезією шляхом вільного падіння вантажу масою450 гз висоти1,5 м. Внутрішньошлуночкову інфузію катіонних ліпосом DOTAP, що несли 25 мкг плазмідного вектору pCMV•SPORT6 з кДНК гена APOE3 здійснювали за допомогою осмотичних помп ALZET. Вираженість посттравматичного неврологічного дефіциту оцінювали за шкалою рухової дисфункції в день нанесення травми та з 1-ї до 7-ї доби після травми. Когнітивні функції (просторова пам’ять та здатність до навчання) оцінювали у водному лабіринті Морріса протягом 7–10 діб після травми. Результати дослідження свідчать, що індукція синтезу ізоформи 3 apoE за допомогою плазмідного вектору, що доставлявся в клітини за допомогою катіонних ліпосом, сприяє більш швидкому регресові неврологічних і когнітивних розладів при експериментальній ЧМТ