Background. Cross-sectionally, lower trunk muscle attenuation (higher fat infiltration) has been associated with poorer physical function in older adults. We hypothesize that lower trunk muscle ...attenuation will be associated with lower functional capacity 3 years later and that back pain status will moderate this relationship. Methods. The study sample consisted of a biracial cohort of well functioning men (739) and women (788) aged 70–79 years from the Pittsburgh site of the Health, Aging and Body Composition (Health ABC) study. Computed tomography was used to measure trunk muscle area and attenuation of the lumbar paraspinal, lateral abdominal, and rectus abdominus muscles at baseline. The Health ABC Physical Performance Battery (usual and narrow walk, chair stands, and standing balance) was used to measure functional capacity at the first and fourth annual clinic visits. Results. Regardless of back pain status, average trunk muscle attenuation (but not muscle area) was positively associated with overall physical performance, particularly balance (p <.01), in a fully adjusted model. The association between trunk attenuation and functional capacity was significantly stronger in participants with at least moderate back pain in the year prior to baseline (p <.05 for interaction; attenuation × back pain). Participants with moderate to extreme back pain had a greater decline in function over time (p <.05). Conclusions. Older adults with poorer trunk muscle composition (higher fat infiltration) exhibit reduced functional capacity, especially balance, 3 years later. Improving trunk muscle composition may be an important yet overlooked approach to maintain function and potentially reduce balance impairments, particularly in persons with a history of back pain.
ABSTRACT
Recently, we demonstrated how an astrophotonic light reformatting device, based on a multicore fibre photonic lantern and a 3D waveguide component, can be used to efficiently reformat the ...point spread function of a telescope to a diffraction-limited pseudo-slit. Here, we demonstrate how such a device can also efficiently mitigate modal noise – a potential source of instability in high-resolution multimode fibre-fed spectrographs. To investigate the modal noise performance of the photonic reformatter, we have used it to feed light into a bench-top near-infrared spectrograph (R ≈ 7000, λ ≈ 1550 nm). One approach to quantifying the modal noise involved the use of broad-band excitation light and a statistical analysis of how the overall measured spectrum was affected by variations in the input coupling conditions. This approach indicated that the photonic reformatter could reduce modal noise by a factor of 6 when compared to a multimode fibre with a similar number of guided modes. Another approach to quantifying the modal noise involved the use of multiple spectrally narrow lines, and an analysis of how the measured barycentres of these lines were affected by variations in the input coupling. Using this approach, the photonic reformatter was observed to suppress modal noise to the level necessary to obtain spectra with stability close to that observed when using a single mode fibre feed. These results demonstrate the potential of using photonic reformatters to enable efficient multimode spectrographs that operate at the diffraction-limit and are free of modal noise, with potential applications including radial velocity measurements of M-dwarfs.
In this study, we demonstrate that two important regulators of the cell cycle, cyclin-dependent kinase-4 and its inhibitor p16, are increased in the brains of cases of Alzheimer's disease patients ...compared with age-matched controls. Both proteins are increased in the pyramidal neurons of the hippocampus, including those neurons containing neurofibrillary tangles and granulovacuolar degeneration. As p16 is not normally found in terminally differentiated neurons, it seems paradoxical that it is increased in Alzheimer's disease unless it is responding to increases in cyclin-dependent kinase-4 or other cell cycle regulators. Induction of the latter, a protein that signals re-entry and progression through the cell cycle, may itself be the consequence of alpha response to a growth stimulus. Re-entry into the cell cycle is likely deleterious in terminally differentiated neurons and may contribute to the biochemical abnormalities, such as oxidative stress and hyperphosphorylated tau protein, as well as the neuronal degeneration characteristic of the pathology of Alzheimer's disease.
Natural organic matter (NOM) plays a significant role in fouling microfiltration membranes in drinking water treatment processes even though the NOM is retained only to a small extent. The aim of ...this study was to obtain a better understanding of the interactions between the fractional components of NOM and microfiltration membranes. Filtration experiments were performed using 0.22
μm hydrophobic and hydrophilic polyvinylidene fluoride (PVDF) membranes in a stirred-cell system on the NOM isolated from three Australian surface waters. As expected, the fouling rate for the hydrophobic membrane was considerably greater than for the hydrophilic membrane. Focusing on the hydrophobic membrane, it was shown that the high molecular weight fraction of NOM (>30
kDa) was responsible for the major flux decline. Filtration tests on the four fractions of NOM isolated on the basis of hydrophobicity and charge using non-functionalised and anionic resins revealed that the fouling potential for the three waters was hydrophilic neutral>hydrophobic acids>transphilic acids>hydrophilic charged. The low-aromatic hydrophilic neutral compounds were the main determinant of the rate and extent of flux decline. This was linked to the colloidal size fraction (>30
kDa) and to the selective concentration of calcium in the fraction leading to organics-Ca
2+ bridging. It was also shown that the higher the aromaticity of the NOM the greater the flux decline, and the aromatics mainly resided in the hydrophobic acids fraction. Overall, the fouling mechanism controlling the flux decline involved the combined effects of adsorptive and colloidal fouling by the hydrophilic neutral fraction in the internal pore structure of the membrane.
Carbon nanotubes for power applications Raffaelle, R.P.; Landi, B.J.; Harris, J.D. ...
Materials science & engineering. B, Solid-state materials for advanced technology,
02/2005, Volume:
116, Issue:
3
Journal Article
Peer reviewed
Carbon nanotubes have been found to possess a wide variety of extremely remarkable properties, most notably high electrical and thermal conductivity, mechanical strength, and catalytic surface area. ...These properties imbue carbon nanotubes with tremendous potential for a variety of power generation and storage devices including: lithium-ion (Li
+) batteries, polymeric solar cells, proton exchange membrane (PEM) fuel cells, and thermionic power devices. A review of the key issues surrounding synthesis, characterization, and processing of carbon nanotubes in relation to device fabrication will be highlighted. Results on a variety of prototype devices which are being developed by the NanoPower Research Laboratories (NPRL) at RIT in collaboration with researchers at the NASA Glenn Research Center will be presented.
BMD was examined in users of NSAIDs (by COX selectivity) and aspirin in the Health ABC cohort (n = 2853). Significantly higher BMD was found in users of relative COX‐2 selective NSAIDs with aspirin ...(COX‐2/ASA) compared with nonusers. This suggests a role for COX‐2/ASA in osteoporosis.
Introduction: The purpose of this study was to determine the relationship of nonsteroidal anti‐inflammatory drug (NSAID) use, by cyclo‐oxygenase selectivity (COX), and aspirin use on bone mineral density (BMD) in participants from the Health, Aging, and Body Composition (Health ABC) population‐based cohort. It is known that NSAIDs inhibit the COX enzyme and decrease production of prostaglandins, which are involved in regulation of bone turnover. COX has two isoforms, COX‐1 and COX‐2. Production of prostaglandins associated with bone loss is primarily mediated through the COX‐2 pathway. In addition, aspirin may have effects on bone independent of the prostaglandin pathway.
Materials and Methods: NSAID (by COX selectivity) and aspirin use and BMD were assessed in 2853 adults (49.5% women, 50.5% men; 43.1% black, 56.9% white; mean age: 73.6 years) from the Health ABC cohort. For the purposes of this analysis, relative COX‐1 selective NSAIDs were defined as having a ratio of COX‐1 IC50 to COX‐2 IC50 of >1 in whole blood, and relative COX‐2 selective NSAIDs were defined as having a ratio of COX‐1 IC50 to COX‐2 IC50 of <1 in whole blood. Analysis of covariance was used to compare BMD across each NSAID use and aspirin use category adjusting for age, race, gender, weight, height, study site, calcium and vitamin D supplementation, Womac score, history of rheumatoid arthritis, history of arthritis other than rheumatoid, and smoking status.
Results: After adjustment for possible confounders, current use of relative COX‐2 selective NSAIDs with aspirin was associated with higher BMD at the whole body (4.2%, 1.2–7.3 CI) and total hip (4.6%, 0.5–8.8 CI) by DXA and at both trabecular (34.1%, 15.4–52.7 CI) and cortical spine (12.8%, 2.3–23.3 CI) by quantitative computed tomography.
Conclusions: Our data suggest that the combination of relative COX‐2 selective NSAIDs and aspirin is associated with higher BMD at multiple skeletal sites in men and women.
Microbes and microbial components potentially impact the performance of pigs through immune stimulation and altered metabolism. These immune modulating factors can include endotoxin from gram ...negative bacterial outer membrane component, commonly referred to as lipopolysaccharide (LPS). In this study, our objective was to examine the relationship between intestinal barrier integrity, endotoxin and inflammation with feed efficiency (FE), using pig lines divergently selected for residual feed intake (RFI) as a model. Twelve gilts (62 ± 3 kg BW) from the low RFI (LRFI, more efficient) and 12 from the high RFI (HRFI, less efficient) were used. Individual performance data was recorded for 5 wk. At the end of the experimental period, ADFI of LRFI pigs was less (P < 0.001), ADG not different between the 2 lines (P = 0.72) but the G:F of LRFI pigs was greater than for HRFI pigs (P = 0.019). Serum endotoxin concentration (P < 0.01) and the acute phase protein haptoglobin (P < 0.05) were greater in HRFI pigs. Transepithelial resistance of the ileum, transport of fluorescein isothiocyanate labeled-Dextran and-LPS in ileum and colon, as well as tight junction protein mRNA expression in ileum, did not differ between the lines, indicating the 2 lines did not differ in transport characteristics at the intestinal level. Ileum inflammatory markers, myeloperoxidase (P < 0.05) and IL-8 (P < 0.10), were found to be greater in HRFI pigs. Alkaline phosphatase (ALP) activity was significantly increased in the LRFI pigs in ileum and liver tissues and negatively correlated with blood endotoxin (P < 0.05). Lysozyme activity in the liver was not different between the lines; however, the LRFI pigs had a twofold greater lysozyme activity in ileum (P < 0.05). Despite the difference in their activity, ALP or lysozyme mRNA expression was not different between the lines in either tissue. Decreased endotoxin and inflammatory markers and the enhanced activities of antimicrobial enzymes in the LRFI line may not fully explain the difference in the FE between the lines, but they have the potential to prevent the growth potential in HRFI pigs. Further studies are needed to identify the other mechanisms that may contribute to the greater endotoxin and acute phase proteins in the HRFI pigs and the greater FE in the LRFI pigs.
Midcrustal rocks in retrograde metamorphic settings are typically H2O-undersaturated and fluid-absent and have low permeability. Exhumed continental retrograde faults, nonetheless, show evidence for ...the operation of fluid-mediated weakening mechanisms during deformation at midcrustal conditions. To explore the origin and effects of fluids in retrograde faults, we study the Kuckaus Mylonite Zone (KMZ), an exhumed crustal-scale, strike-slip shear zone in the southern Namibian Namaqua Metamorphic Complex. The KMZ deformed quartzofeldspathic migmatised gneisses at midcrustal retrograde conditions (450-480°C, 270-420 MPa) in the Mesoproterozoic, 40 Ma after granulite facies peak metamorphism at 825°C and 550 MPa. The mylonites contain fully hydrated retrograde mineral assemblages, predominantly adjacent to anastomosing high-strain zones, providing evidence of local H2O saturation and fluid presence during deformation. Whole rock and quartz vein δ18O values suggest that at least some of the fluids were meteoric in origin. The rocks across the shear zone retain the effect of different protoliths, implying little effect of fluid-rock interaction on whole rock major element chemistry. Together with a general scarcity of quartz veins, this suggests that fluid/rock ratios remained low in the KMZ. However, even small amounts of H2O allowed reaction weakening and diffusion-precipitation, followed by growth and alignment of phyllosilicates. In the ultramylonites, a fine grain size in the presence of fluids allowed for grain size sensitive creep. We conclude that the influx of even small volumes of fluids into retrograde shear zones can induce drastic weakening by facilitating grain size sensitive creep and retrograde reactions. In retrograde settings, these reactions consume fluids, and therefore elevated fluid pressures will only be possible after considerable weakening has already occurred. Our findings imply that the range of seismic styles recently documented at active retrograde transform faults may not require high fluid pressures but could also arise from other local weakening mechanisms.
Loss of E-cadherin marks a defect in epithelial integrity and polarity during tissue injury and fibrosis. Whether loss of E-cadherin plays a causal role in fibrosis is uncertain. α3β1 Integrin has ...been identified to complex with E-cadherin in cell-cell adhesion, but little is known about the details of their cross talk. Herein, E-cadherin gene ( Cdh1 ) was selectively deleted from proximal tubules of murine kidney by Sglt2Cre . Ablation of E-cadherin up-regulated α3β1 integrin at cell-cell adhesion. E-cadherin–deficient proximal tubular epithelial cell displayed enhanced transforming growth factor-β1–induced α-smooth muscle actin (α-SMA) and vimentin expression, which was suppressed by siRNA silencing of α3 integrin, but not β1 integrin. Up-regulation of transforming growth factor-β1–induced α-SMA was mediated by an α3 integrin-dependent increase in integrin-linked kinase (ILK). Src phosphorylation of β-catenin and consequent p-β-catenin-Y654/p-Smad2 transcriptional complex underlies the transcriptional up-regulation of ILK. Kidney fibrosis after unilateral ureteric obstruction or ischemia reperfusion was increased in proximal tubule E-cadherin–deficient mice in comparison to that of E-cadherin intact control mice. The exacerbation of fibrosis was explained by the α3 integrin-dependent increase of ILK, β-catenin nuclear translocation, and α-SMA/proximal tubular–specific Cre double positive staining in proximal tubular epithelial cell. These studies delineate a nonconventional integrin/ILK signaling by α3 integrin–dependent Src/p-β-catenin-Y654/p-Smad2–mediated up-regulation of ILK through which loss of E-cadherin leads to kidney fibrosis.
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