773 research outputs found
Mitochondrial DNA: the overlooked oncogenome?
Perturbed mitochondrial bioenergetics constitute a core pillar of cancer-associated metabolic dysfunction. While mitochondrial dysfunction in cancer may result from myriad biochemical causes, a historically neglected source is that of the mitochondrial genome. Recent large-scale sequencing efforts and clinical studies have highlighted the prevalence of mutations in mitochondrial DNA (mtDNA) in human tumours and their potential roles in cancer progression. In this review we discuss the biology of the mitochondrial genome, sources of mtDNA mutations, and experimental evidence of a role for mtDNA mutations in cancer. We also propose a 'metabolic licensing' model for mtDNA mutation-derived dysfunction in cancer initiation and progression
Evaluation of soil-tire interaction on a soil bin
A single wheel tester with the attention to the size of soil bin has been designed and fabricated to study soil tire interactions, in controlled soil environment. The main parts of a single wheel tester include chassis, reduction gear unit, three-phase AC electric motor, hydraulic cylinder, tank, pump and valve, load cell and tires. The experiment was designed with two levels of tire axle loads (15 and 25 kN) and two inflation pressures (70 and 150 kPa). The tire (18.4/15-30) was run at a constant forward speed of 0.3 m s-1, 13% slip and 12% moisture content(d.b.) on clay loam soil. A statistical comparison was made for the cone index values measured in the undisturbed soil, at the center of the track, and at the edge of the track. A significant difference in cone index was found for all treatments. Inflation pressure at the center and load at the edge of tire track has significant effect on cone index and dry bulk density. Keywords: cone index, inflation pressure, load; dry bulk density, soil bi
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Epidemiology of gastroschisis: A population-based study in California from 1995 to 2012.
BackgroundAlthough the incidence of gastroschisis is increasing, risk factors are not clearly identified.MethodsUsing the Linked Birth Database from the California Office of Statewide Health Planning and Development from 1995 to 2012, patients with gastroschisis were identified by ICD-9 diagnosis/procedure code or birth certificate designation. Logistic regressions examined demographics, birth factors, and maternal exposures on risk of gastroschisis.ResultsThe prevalence of gastroschisis was 2.7 cases per 10,000 live births. Patients with gastroschisis had no difference in fetal exposure to alcohol (p = 0.609), narcotics (p = 0.072), hallucinogenics (p = 0.239), or cocaine (p = 0.777), but had higher exposure to unspecified/other noxious substances (OR 3.27, p = 0.040; OR 2.02, p = 0.002). Gastroschisis was associated with low/very low birthweight (OR 5.08-16.21, p < 0.001) and preterm birth (OR 3.26-10.0, p < 0.001). Multivariable analysis showed lower risk in black (OR 0.44, p < 0.001), Asian/Pacific Islander (OR 0.76, p = 0.003), and Hispanic patients (OR 0.72, p < 0.001) compared to white patients. Risk was higher in rural areas (OR 1.24-1.76, p = 0.001). Compared to women age < 20, risk decreased with advancing maternal age (OR 0.49-OR 0.03, p < 0.001). Patients with gastroschisis had increased total charges (9012, p < 0.001) and length of stay (38.1 vs. 2.9 days, p < 0.001). Mortality was 4.6%.ConclusionsThis is the largest population-based study summarizing current epidemiology of gastroschisis in California.Type of studyRetrospective comparative cohort study.Level of evidenceIII
C7orf30 is necessary for biogenesis of the large subunit of the mitochondrial ribosome
Defects of the translation apparatus in human mitochondria are known to cause disease, yet details of how protein synthesis is regulated in this organelle remain to be unveiled. Here, we characterize a novel human protein, C7orf30 that contributes critically to mitochondrial translation and specifically associates with the large subunit of the mitochondrial ribosome (mt-LSU). Inactivation of C7orf30 in human cells by RNA interference results in respiratory incompetence owing to reduced mitochondrial translation rates without any appreciable effects on the steady-state levels of mitochondrial mRNAs and rRNAs. Ineffective translation in C7orf30-depleted cells or cells overexpressing a dominant-negative mutant of the protein results from aberrant assembly of mt-LSU and consequently reduced formation of the monosome. These findings lead us to propose that C7orf30 is a human assembly and/or stability factor involved in the biogenesis of the large subunit of the mitochondrial ribosome
Designing a Network of Battery Swap Stations for Supporting UAVs in Long-range Delivery Operations
Recently, the use of Unmanned Aerial Vehicle (UAV) for delivery services has become a topic of interest and research for large commercial service providers such as Google and Amazon. The delivery speed of UAVs provides such companies with a significant advantage in their market. Although utilizing the UAVs in product delivery has received tremendous excitement, several issues need to be resolved prior to real-world implementation. The first issue with using UAVs as a transportation mode is their limited flying range. Small UAVs are not able to fly long distances due to their limited battery life. Flight range can be improved by using battery swapping stations in the planning horizon. UAVs can replace their depleted batteries at these stations and continue their fights. In our research, we attempt to develop a model to construct a network of such stations in order to enable the UAVs to fly long distances for making deliveries to far-reaching demand points. In addition, we develop a Tabu-Search heuristic to solve several instances of the proposed problem
Communication: Nanosize-induced restructuring of Sn nanoparticles
Stabilities and structures of β- and α-Sn nanoparticles are studied using
density functional theory. Results show that β-Sn nanoparticles are more
stable. For both phases of Sn, nanoparticles smaller than 1 nm (∼48 atoms) are
amorphous and have a band gap between 0.4 and 0.7 eV. The formation of band
gap is found to be due to amorphization. By increasing the size of Sn
nanoparticles (1–2.4 nm), the degree of crystallization increases and the band
gap decreases. In these cases, structures of the core of nanoparticles are
bulk-like, but structures of surfaces on the faces undergo reconstruction.
This study suggests a strong size dependence of electronic and atomic
structures for Sn nanoparticle anodes in Li-ion batteries
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Mitochondrial Genome Engineering: The Revolution May Not Be CRISPR-Ized.
In recent years mitochondrial DNA (mtDNA) has transitioned to greater prominence across diverse areas of biology and medicine. The recognition of mitochondria as a major biochemical hub, contributions of mitochondrial dysfunction to various diseases, and several high-profile attempts to prevent hereditary mtDNA disease through mitochondrial replacement therapy have roused interest in the organellar genome. Subsequently, attempts to manipulate mtDNA have been galvanized, although with few robust advances and much controversy. Re-engineered protein-only nucleases such as mtZFN and mitoTALEN function effectively in mammalian mitochondria, although efficient delivery of nucleic acids into the organelle remains elusive. Such an achievement, in concert with a mitochondria-adapted CRISPR/Cas9 platform, could prompt a revolution in mitochondrial genome engineering and biological understanding. However, the existence of an endogenous mechanism for nucleic acid import into mammalian mitochondria, a prerequisite for mitochondrial CRISPR/Cas9 gene editing, remains controversial
A review of hough transform and line segment detection approaches
In a wide range of image processing and computer vision problems, line segment detection is one of the most critical challenges. For more than three decades researchers have contributed to build more robust and accurate algorithms with faster performance. In this paper we review the main approaches and in particular the Hough transform and its extensions, which are among the most well-known techniques for the detection of straight lines in a digital image. This paper is based on extensive practical research and is organised into two main parts. In the first part, the HT and its major research directions and limitations are discussed. In the second part of the paper, state-of-the-art line segmentation techniques are reviewed and categorized into three main groups with fundamentally distinctive characteristics. Their relative advantages and disadvantages are compared and summarised in a table
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