Review of mesospheric temperature trends Beig, G.; Keckhut, P.; Lowe, R. P. ...
Reviews of geophysics (1985),
December 2003, Letnik:
41, Številka:
4
Journal Article
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Odprti dostop
In recent times it has become increasingly clear that releases of trace gases from human activity have a potential for causing change in the upper atmosphere. However, our knowledge of systematic ...changes and trends in the temperature of the mesosphere and lower thermosphere is relatively limited compared to the Earth's lower atmosphere, and not much effort has been made to synthesize these results so far. In this article, a comprehensive review of long‐term trends in the temperature of the region from 50 to 100 km is made on the basis of the available up‐to‐date understanding of measurements and model calculations. An objective evaluation of the available data sets is attempted, and important uncertainly factors are discussed. Some natural variability factors, which are likely to play a role in modulating temperature trends, are also briefly touched upon. There are a growing number of experimental results centered on, or consistent with, zero temperature trend in the mesopause region (80–100 km). The most reliable data sets show no significant trend but an uncertainty of at least 2 K/decade. On the other hand, a majority of studies indicate negative trends in the lower and middle mesosphere with an amplitude of a few degrees (2–3 K) per decade. In tropical latitudes the cooling trend increases in the upper mesosphere. The most recent general circulation models indicate increased cooling closer to both poles in the middle mesosphere and a decrease in cooling toward the summer pole in the upper mesosphere. Quantitatively, the simulated cooling trend in the middle mesosphere produced only by CO2 increase is usually below the observed level. However, including other greenhouse gases and taking into account a “thermal shrinking” of the upper atmosphere result in a cooling of a few degrees per decade. This is close to the lower limit of the observed nonzero trends. In the mesopause region, recent model simulations produce trends, usually below 1 K/decade, that appear to be consistent with most observations in this region.
Summary
Background
Matrix metalloproteinase‐9 is a proteolytic enzyme whose expression is increased in ulcerative colitis.
Aim
To evaluate the safety and efficacy of GS‐5745, a fully humanised ...anti‐matrix metalloproteinase‐9 monoclonal antibody, in moderately‐to‐severely active ulcerative colitis.
Methods
We randomised 74 patients with ulcerative colitis to treatment with single or multiple ascending intravenous or subcutaneous doses of GS‐5745 or placebo. Multiple‐dose cohorts received either IV infusions (0.3, 1.0, 2.5 or 5.0 mg/kg GS‐5745 or placebo) every 2 weeks (three total IV infusions) or five weekly SC injections (150 mg GS‐5745 or placebo). The primary outcomes were the safety, tolerability and pharmacokinetics of escalating single and multiple doses of GS‐5745. Exploratory analyses in the multiple‐dose cohorts included clinical response (≥3 points or 30% decrease from baseline in Mayo Clinic score and ≥1 point decrease in the rectal bleeding subscore or a rectal bleeding subscore ≤1) and clinical remission (a complete Mayo Clinic score ≤2 with no subscore >1) at Day 36. Biological effects associated with a clinical response to GS‐5745 were explored using histological and molecular approaches.
Results
Twenty‐three of the 42 patients (55%) receiving multiple doses of GS‐5745 had adverse events, compared with 5/8 patients (63%) receiving placebo. GS‐5745 showed target‐mediated drug disposition, approximately dose‐proportional increases in maximum plasma concentration and more than dose‐proportional increases in the area under the plasma drug concentration‐time curve. Clinical response occurred in 18/42 patients (43%) receiving GS‐5745 compared with 1/8 patients (13%) receiving placebo. Clinical remission occurred in 6/42 patients (14%) receiving GS‐5745 and 0/8 (0%) receiving placebo. Patients with a clinical response to GS‐5745 had reductions in matrix metalloproteinase‐9 tissue levels (mean 48.9% decrease from baseline compared with a mean 18.5% increase in nonresponders, P = 0.008) significant improvements in histopathology scores (confirmed with three separate histological disease activity indices), as well as changes in colonic gene expression that were consistent with reduced inflammation.
Conclusion
This phase 1 trial provides preliminary evidence for the safety and therapeutic potential of GS‐5745 in the treatment of ulcerative colitis.
ABSTRACT
With the erosion of traditional gender-based divisions of labor, more people are struggling to manage both family and career responsibilities simultaneously. Researchers have begun to ...examine decisions and strategies individuals use to manage work and family, though this area of inquiry is still fairly nascent. We used qualitative and quantitative data from 70 individuals at different life stages to examine work-family management strategies adopted by men and women across 4 career-family centrality profiles: career-centric, family-centric, dual-centric, and other-centric. We found that men of all centrality profiles, along with dual-centric and career-centric women, leaned back from family to benefit their careers (e.g., delayed having children). Men and women of all centrality profiles scaled back their work demands to benefit family, yet only women reported stepping out of their work role altogether (including career-centric and dual-centric women). This gender-role-congruent finding of women stepping out was supplemented by men, of all centrality profiles, who adopted work-family management strategies aimed at enabling their current or future wives to step out. The findings suggest that in order to fully understand gender equality in the workplace, it is important to understand the social processes occurring at home, including how men and women jointly negotiate managing the work-family interface.
SCIENTIFIC ABSTRACT
We used qualitative and quantitative data from 70 individuals at different life stages to examine work-family management strategies adopted by men and women across 4 career-family centrality profiles: career-centric, family-centric, dual-centric, and other-centric. Participant interview responses were analyzed using QSR NVivo Version 10. We used a theoretical thematic analysis and a theory-driven coding scheme (Boyatzis, 1998) to examine the data. Data were analyzed in multiple stages carried out by 2 independent coders. We found that men of all centrality profiles, along with dual-centric and career-centric women, leaned back from family to benefit their careers (e.g., delayed having children). Men and women of all centrality profiles scaled back their work demands to benefit family, yet only women reported stepping out of their work role altogether (including career-centric and dual-centric women). This gender-role-congruent finding of women stepping out was supplemented by men, of all centrality profiles, who adopted work-family management strategies aimed at enabling their current or future wives to step out. The findings suggest that in order to fully understand gender equality in the workplace, it is important to understand the social processes occurring at home, including how men and women jointly negotiate managing the work-family interface.
Lipoprotein(a) Lp(a) is a risk factor for atherosclerosis; however, the mechanisms are unclear. We previously reported that Lp(a) stimulated human vascular endothelial cells to produce monocyte ...chemotactic activity. The apolipoprotein(a) apo(a) portion of Lp(a) was the active moiety.
We now describe the identification of the chemotactic activity as being due to the CC chemokine I-309. The carboxy-terminal domain of apo(a) containing 6 type-4 kringles (types 5 to 10), kringle V, and the protease domain was demonstrated to contain the I-309-inducing portion. Polyclonal and monoclonal anti-I-309 antibodies as well as an antibody against a portion of the extracellular domain of CCR8, the I-309 receptor, inhibited the increase in monocyte chemotactic activity induced by apo(a). I-309 antisense oligonucleotides also inhibited the induction of endothelial monocyte chemotactic activity by apo(a). I-309 mRNA was identified in human umbilical vein endothelial cells. Apo(a) induced an increase in I-309 protein in the endothelial cytoplasm and in the conditioned medium. Immunohistochemical studies have identified I-309 in endothelium, macrophages, and extracellular areas of human atherosclerotic plaques and have found that I-309 colocalized with apo(a).
These data establish that I-309 is responsible for the monocyte chemotactic activity induced in human umbilical vein endothelial cells by Lp(a). The identification of the endothelial cell as a source for I-309 suggests that this chemokine may participate in vessel wall biology. Our data also suggest that I-309 may play a role in mediating the effects of Lp(a) in atherosclerosis.
Background. The incidence of pneumococcal pneumonia is greatly increased among human immunodeficiency virus (HIV)-infected subjects, compared with among non-HIV-infected subjects. Lung fluid levels ...of immunoglobulin G (IgG) specific for pneumococcal capsular polysaccharide are not reduced in HIV-infected subjects; therefore, we examined immunoglobulin subtypes and compared lung fluid IgG opsonic function in HIV-infected subjects with that in healthy subjects. Methods. Bronchoalveolar lavage (BAL) fluid and serum samples were collected from 23 HIV-infected and 26 uninfected subjects. None of the subjects were receiving highly active antiretroviral therapy, and none had received pneumococcal vaccination. Pneumococcal capsule-specific IgG levels in serum and BAL fluid were measured by enzyme-linked immunosorbent assay, and IgG was concentrated from 40 mL of BAL fluid. Opsonization and opsonophagocytosis of pneumococci with serum, BAL fluid, and BAL IgG were compared between HIV-infected subjects and healthy subjects. Results. The effect of type 1 pneumococcal capsular polysaccharide-specific IgG in opsonizing of pneumococci was significantly less using both serum and BAL IgG from HIV-infected subjects, compared with serum and BAL IgG from healthy subjects (mean level, 8.9 fluorescence units 95% confidence interval, 8.1–9.7 fluorescence units vs. 12.1 fluorescence units 95% confidence interval, 9.7–15.2 fluorescence units; P = .002 for lung BAL IgG). The opsonophagocytosis of pneumococci observed using BAL IgG from HIV-infected subjects was significantly less than that observed using BAL IgG from healthy subjects (37 fluorescence units per ng of IgG 95% confidence interval, 25–53 fluorescence units per ng of IgG vs. 127 fluorescence units per ng of IgG 95% confidence interval, 109–145 fluorescence units per ng of IgG; P < .001). Conclusion. HIV infection is associated with decreased antipneumococcal opsonic function in BAL fluid and serum.
We measured the size of eggs produced by populations of Drosophila melanogaster that had been collected along latitudinal gradients in different continents or that had undergone several years of ...culture at different temperatures in the laboratory. Australian and South American populations from higher latitudes produced larger eggs when all were compared at a standard temperature. Laboratory populations that had been evolving at 16.5⚬C produced larger eggs than populations that had evolved at 25⚬C or 29⚬C, suggesting that temperature may be an important selective agent in producing the latitudinal clines. Flies from laboratory populations produced larger eggs at an experimental temperature of 16.5⚬C than at 25⚬C, and there was no indication of genotype-environment interaction for egg size. Evolution of egg size in response to temperature cannot be accounted for by differences in adult body size between populations. It is not clear which life-history traits are direct targets of thermal selection and which are showing correlated responses, and disentangling these is a task for the future.
Nonenzymatic attachment of lactose to β-lactoglobulin (β-Lg) was investigated under different conditions. Solubilized conditions, dry environment, and a combination of dry and solubilized ...environments, were examined for their effects on lactosylation. Temperatures ranging from 50 to 65 °C and time intervals between 1 h and 4 days were used. Electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry were implemented to examine the reaction products. Maximum attachment efficiency occurred at 65 °C held for 3 h in dry-way conditions. Incubations held for long periods of time under dry-way conditions suggest possible denaturation. Both ESI and MALDI data suggest β-Lg removal in the solubilized samples held for long periods of time. A combination of solubilized and dry environments led to very similar mass spectrogram results over time. Keywords: β-Lactoglobulin; nonenzymatic; solubilized; dry-way; combination
A coupled channel analysis of the centrally produced
K
+
K
−and
π
+
π
−final states has been performed in
pp collisions at an incident beam momentum of 450 GeV/c. The pole positions and branching ...ratios to
ππ and
K
K
of the
f
0(980),
f
0(1370),
f
0(1500) and
f
0(1710) have been determined. A systematic study of the production properties of all the resonances observed in the
π
+
π
−and
K
+
K
−channels has been performed.
We used a novel approach to study the effects of egg size on offspring fitness components in Drosophila melanogaster. Populations that differed genetically in egg size were crossed, and the female ...offspring from these reciprocal crosses were examined for life-history traits. These flies expressed effects of egg size, because they developed from eggs of different sizes as a result of maternal genetic effects, but displayed an equivalent range of nuclear genetic variation. The crosses used four independent pairs of outbred populations that differed in the pattern of covariation between egg size and life-history traits, so that the maternal genetic effects of egg size on offspring characters could be contrasted to the associations present among the parental populations. Egg size showed positive maternal genetic effects on embryonic viability and development rate, hatchling weight and feeding rate, and egg-larva and egg-adult development rate but no consistent effects on larval competitive ability, adult weight, or egg size in the offspring. Our method revealed a pattern of causality that could not be deduced from interpopulation comparisons and therefore provides a good way of disentangling the causes and consequences of variation in egg size while controlling for zygotic genetic effects.
We compared threshold voltage shifts in amorphous Si, microcrystalline Si and polycrystalline Si thin-film transistors (TFTs) in terms of a recently developed thermalization energy concept for a ...dangling-bond defect state creation in amorphous Si TFTs. The rate of the threshold voltage shift in microcrystalline Si TFTs was much lower than in amorphous Si TFTs, but the characteristic energy for the process, which we identified as the mean energy to break a Si–Si bond, was virtually the same. This suggests that the same basic Si–Si bond breaking process was responsible for the threshold voltage shift in both cases. The lower magnitude in microcrystalline Si TFTs was due to a much lower attempt frequency for the process. We interpreted the attempt frequency in amorphous and microcrystalline silicon in terms of the localization length of the electron wavefunction and the effect of stabilizing H atoms being located only at grain boundaries.
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