It is known that computational loads of the propagator method (PM) can be significantly smaller, e.g., one or two order, than those of MUSIC and ESPRIT because the PM does not require any eigenvalue ...decomposition (EVD) of the cross-correlation matrix and singular value decomposition (SVD) of the received data. However, the PM of the parallel shape array has nonnegligible drawbacks such as 1) requirement of pair matching between the 2-D azimuth and elevation angle estimation which is an exhaustive search and 2) estimation failure problems when elevation angles are between 70/spl deg/ and 90/spl deg/. The purpose of this paper is to show a way to remove these problems in the PM without additional computational loads. This paper will employ one or two L-shape arrays because the parallel shape used in the PM may cause the aforesaid problems. Simulation results verify that the PM with one or two L-shape configurations can remove these problems and improve the performance of the PM significantly, e.g., almost 5 dB in signal to noise ratio for the parameters used in this paper.
Dps, the DNA-binding protein from starved cells, is capable of providing protection to cells during exposure to severe environmental assaults; including oxidative stress and nutritional deprivation. ...The structure and function of Dps have been the subject of numerous studies and have been examined in several bacteria that possess Dps or a structural/functional homologue of the protein. Additionally, the involvement of Dps in stress resistance has been researched extensively as well. The ability of Dps to provide multifaceted protection is based on three intrinsic properties of the protein: DNA binding, iron sequestration, and its ferroxidase activity. These properties also make Dps extremely important in iron and hydrogen peroxide detoxification and acid resistance as well. Regulation of Dps expression in E. coli is complex and partially dependent on the physiological state of the cell. Furthermore, it is proposed that Dps itself plays a role in gene regulation during starvation, ultimately making the cell more resistant to cytotoxic assaults by controlling the expression of genes necessary for (or deleterious to) stress resistance. The current review focuses on the aforementioned properties of Dps in E. coli, its prototypic organism. The consequences of elucidating the protective mechanisms of this protein are far-reaching, as Dps homologues have been identified in over 1000 distantly related bacteria and Archaea. Moreover, the prevalence of Dps and Dps-like proteins in bacteria suggests that protection involving DNA and iron sequestration is crucial and widespread in prokaryotes.
Abstract Background The contralateral femur is often used as reference for reconstruction in unilateral hip joint pathology. The objective of this study was to quantify the side-to-side variation in ...proximal femur. We hypothesized that significant side-to-side differences exist between left and right femur with implications for preoperative planning and leg length discrepancy following hip arthroplasty. Materials and methods CT-based 3D femoral models were reconstructed for 122 paired femurs in 61 young healthy subjects (46.9 ± 6.8 years) with no history of hip pathology. Side-to-side differences of several femoral morphologic parameters, including femoral head diameter, femoral anteversion, horizontal offset and femoral head center location, were compared and correlated with demographic factors using multiple linear regression. Results Significant side-to-side differences ( P < 0.01) were found in femoral anteversion (4.3 ± 3.8°; range: 0.2° to 17.3°), horizontal offset (2.5 ± 2.1 mm; range: 0.1 to 10.3 mm), and femoral head center location (7.1 ± 3.8 mm; range: 0.5 to 19.4 mm). The difference in femoral anteversion was strongly correlated with the difference in neck diameter (R2 = 0.79), whereas the difference in horizontal femoral offset was highly correlated with the head diameter difference (R2 = 0.72). Femoral head center difference was correlated with the femoral anteversion, horizontal offset and neck-shaft-angle difference (R2 = 0.82). Discussion Relying on the anatomic landmarks of the contralateral femur during hip arthroplasty may not necessarily result in restoration of native anatomy and leg-length. Knowledge of the baseline side-to-side asymmetry could provide a range of error that would be tolerable following hip reconstruction. Level of evidence Level IV. Type of study Retrospective observational study.
Background and purpose
The brain's cholinergic network has various interconnections with the cortical and subcortical structures. Disruption of cholinergic pathways by white matter hyperintensities ...(WMH) may cause pathologic changes within brain regions. Thus, WMH may represent an important pathological contributor to subcortical vascular cognitive impairment (scVCI). We aimed to investigate associations between the magnitude of WMH and volumetric changes in cortical and subcortical regions innervated by cholinergic neurons in patients with scVCI.
Methods
We enrolled patients with scVCI, defined as moderate to severe WMH or multiple (>2) lacunar infarcts outside the brainstem. Cholinergic Pathway HyperIntensities Scale (CHIPS) scores were used to quantify the magnitude of cholinergic pathway disruptions by WMH. We measured cortical thickness and subcortical volumes of 11 brain regions innervated by cholinergic neurons. Partial correlation of brain region volumes with total CHIPS scores was obtained using multiple linear regression.
Results
In total, 80 patients were enrolled. The mean age was 78.4 ± 6.5 years, median Mini‐Mental State Examination score was 17 (interquartile range, 13–20) and median CHIPS score was 11 (interquartile range, 7–17). CHIPS scores were positively correlated with subcortical volumes of the putamen (rʹ = 0.46, P = 0.002) and pallidum (rʹ = 0.45, P = 0.002), and were negatively associated with inferior temporal (rʹ = −0.35, P = 0.002) and medial orbitofrontal (rʹ = −0.32, P = 0.002) cortical thickness.
Conclusion
Our study suggested that WMH in cholinergic pathways may contribute to volumetric structural changes in cortical and subcortical structures innervated by cholinergic neurons.
Background and purpose
In 2013, the American College of Cardiology/American Heart Association (ACC/AHA) introduced a novel pooled cohort risk (PCR) model for atherosclerotic cardiovascular disease. ...In this study, we evaluated the relationship between the PCR score and cerebral large‐ and small‐vessel diseases (cLVD and cSVD) in a healthy population,
Methods
We assessed consecutive health check‐up volunteers from 2006 to 2013. We calculated the estimated 10‐year atherosclerotic cardiovascular disease risk as the PCR score based on the 2013 ACC/AHA guidelines. We evaluated both cSVD/cLVD, including the prevalence of cLVD, lacunes and cerebral microbleed (CMB), and the volume of white matter hyperintensity (WMH). In addition to PCR score, the risk factors that were associated with outcome variables at P < 0.10 in univariate analysis were included for further multivariable linear or regression analyses.
Results
A total of 2720 participants were evaluated (mean age, 57 years, male sex, 54%). In multivariable analysis, PCR score was associated with WMH volume β = 0.361; 95% confidence interval (CI), 0.320–0.402, P < 0.001, cLVD adjusted odds ratio (aOR), 1.66; 95% CI, 1.29–2.16, P < 0.001, lacunes (aOR, 1.80; 95% CI, 1.52–2.14, P < 0.001) and CMBs (aOR, 1.75; 95% CI, 1.40–2.19, P < 0.001). Furthermore, PCR score also showed dose‐response tendencies according to the burden of cLVD, WMH, lacunes and CMB.
Conclusions
A higher PCR score based on the ACC/AHA guidelines is closely associated with a higher prevalence and burden of cLVD and cSVD.
Background and purpose
Although non‐alcoholic fatty liver disease (NAFLD) shares common cardiovascular risk factors with cerebral white matter hyperintensity (WMH), few studies have reported the ...association between NAFLD and WMH. The association between the presence of NAFLD with its severity and the volume of WMH was investigated.
Methods
This cross‐sectional study was conducted for 2460 subjects who voluntarily participated in health screening check‐ups including brain magnetic resonance imaging and liver ultrasonography at the Health Promotion Center at Seoul National University Hospital from 2009 to 2013. Ultrasonography was used to detect the presence and severity of NAFLD combined with the NAFLD fibrosis score and the FIB‐4 index. The volume of WMH was measured using a semi‐automated quantification method by a trained neurologist.
Results
The prevalence of NAFLD was 36.5%, and the median volume of WMH in all the subjects was 1.1 ml (interquartile range 0.2–2.7 ml). The presence of NAFLD was associated with a smaller volume of WMH β (standard error, SE) −0.051 (0.046); P = 0.012. Moderate to severe NAFLD was associated with a smaller volume of WMH than was non‐NAFLD β (SE) −0.067 (0.061); P = 0.002. The negative correlation observed between NAFLD severity and WMH volume was persistent only in those with low FIB‐4 index and low NAFLD fibrosis scores, whereas there was a positive association in those with high FIB‐4 index and NAFLD fibrosis scores.
Conclusions
Non‐alcoholic fatty liver disease, and its severity, showed a favorable association with WMH volume. However, its causality and mechanism should be evaluated in further relevantly designed studies.
To gain better understanding of the distributions of the culturable
species in the chicken intestinal tract, we collected ceca, and distal ileum from 10 3-weeks-old broiler chickens.
strains from ...cecal lumen contents (M-CL), and those associated with mucosa of ceca (M-CM) and ileum (M-IM) were recovered on de Man, Rogosa and Sharpe (MRS) agar plates, and used for microbiota analysis. The total cecal content (T-CL) was also used directly for microbiota analysis. We purposefully focused on MRS-recovered populations to gain understanding of the culturable subpopulations of
, since the culturability is an important phenotype in order to exploit the chicken gut microbiota as a resource for development of probiotics. The V1-V3 regions of 16S rRNA gene was amplified from genomic DNA samples, and the pooled amplicons were analyzed by MiSeq sequencing with paired-end read 300 cycle option. Among MRS groups,
were significantly higher in M-IM and M-CL as compared to M-CM, whereas
were significantly higher in M-CM as compared to M-IM and M-CL at
< 0.05. Among
,
(36%) and
(21%) were higher in M-IM as compared to M-CL (
, 28%;
, 15%), and M-CM (
, 20%;
, 11%).
was found significantly higher in M-CL as compared to M-IM (
< 0.01) whereas
was found significantly higher in M-IM as compared to M-CM (
< 0.05).
, and
were only observed in T-CL. In summary,
populations recovered on MRS vary with different regions and locations in chicken GIT, which might indicate their distinct functional roles in different gastrointestinal tract (GIT) niches, and some species of
are not culturable on MRS agar media. This study is the first attempt to define culturable
subpopulations in the chicken intestinal tract comprehensively using 16S rRNA gene profiling, and the findings of this study will be used as a platform to develop a new strategy for isolation of effective
probiotic candidates based on comparative analyses of chicken gut microbiota.
Abstract
A significant challenge in our understanding of biological systems is the high number of genes with unknown function in many genomes. The fungal genus Aspergillus contains important ...pathogens of humans, model organisms, and microbial cell factories. Aspergillus niger is used to produce organic acids, proteins, and is a promising source of new bioactive secondary metabolites. Out of the 14,165 open reading frames predicted in the A. niger genome only 2% have been experimentally verified and over 6,000 are hypothetical. Here, we show that gene co-expression network analysis can be used to overcome this limitation. A meta-analysis of 155 transcriptomics experiments generated co-expression networks for 9,579 genes (∼65%) of the A. niger genome. By populating this dataset with over 1,200 gene functional experiments from the genus Aspergillus and performing gene ontology enrichment, we could infer biological processes for 9,263 of A. niger genes, including 2,970 hypothetical genes. Experimental validation of selected co-expression sub-networks uncovered four transcription factors involved in secondary metabolite synthesis, which were used to activate production of multiple natural products. This study constitutes a significant step towards systems-level understanding of A. niger, and the datasets can be used to fuel discoveries of model systems, fungal pathogens, and biotechnology.
PDF
