bluuebunny/crossref_metadata_2025 huggingface dataset:
Paraoxonase 1 Activity in Chylomicrons and VLDL: The Effect of Type 2 Diabetes and Meals Rich in Saturated Fat and Oleic Acid
Authors: Manning Patrick J. , de Jong Sylvia A. , Ryalls Anne R. , Sutherland Wayne H. F.
Published: December 2011

Paraoxonase 1 (PON 1) has antioxidant and cardioprotective properties and is abnormally low in type 2 diabetic serum. This study aimed to determine the effect of type 2 diabetes and meals rich in saturated fat and oleic acid on PON1 activity in chylomicrons and very low density lipoproteins (VLDL). PON1 arylesterase activity was measured in chylomicrons and VLDL that were isolated in serum from 20 patients with type 2 diabetes and 20 age‐ and gender‐matched, overweight controls 3 h after meals rich in cream or olive oil in a randomized, cross‐over study. Chylomicron–PON1 activity (45%, P = 0.02), ratio chylomicron–PON1/chylomicron–triacylglycerides (TAG) (42%, P = 0.03) and chylomicron–protein content (46%, P < 0.001) were significantly lower in patients with type 2 diabetes compared with controls after the olive oil meal with comparable findings after the meal rich in cream. After ingestion of olive oil, chylomicron–PON1 activity was significantly higher in controls (P = 0.01) and marginally higher (P = 0.06) in diabetic patients and chylomicron–TAG were significantly (P < 0. 05) higher in both groups of subjects, compared with values after ingestion of cream. VLDL–PON1 increased (two‐fold) significantly (P < 0.003) during both meals. Chylomicron‐PON1 activity was correlated significantly with chylomicron–protein (P < 0.001, n = 40) and with postprandial serum PON1 activity (P ≤ 0.001, n = 40). Our data suggest that type 2 diabetes is associated with abnormally low chylomicron–PON1 activity after fatty meals and this may be linked to lower chylomicron–protein content and serum PON1 activity. Switching from saturated fat to olive oil in the meal increases PON1 activity in the chylomicron fraction largely due to increased numbers of chylomicron particles.
A Kinetic Model Describing Antioxidation and Prooxidation of β‐Carotene in the Presence of α‐Tocopherol and Ascorbic Acid
Authors: Shibasaki‐Kitakawa Naomi , Murakami Masahiko , Kubo Masaki , Yonemoto Toshikuni
Published: December 2011

β‐Carotene oxidation in the presence of both lipophilic α‐tocopherol and hydrophilic ascorbic acid was experimentally studied in a biphasic oil–water system. Ascorbic acid in the water phase had two opposite effects of promoting and suppressing α‐tocopherol consumption in the oil phase and indirectly participated in the antioxidation and prooxidation of β‐carotene in the oil phase. The drastic antioxidation of β‐carotene by stopping the consumption of α‐tocopherol was caused by the depletion of oxygen in the system due to the oxidation of ascorbic acid. A kinetic model was constructed by incorporating the oxidation of ascorbic acid itself in the water phase, the regeneration and consumption of α‐tocopherol by ascorbic acid at the oil–water interface, and the oxygen mass transfer across the gas–oil interface and the oil–water interface. The model well described the antioxidation and prooxidation behavior of β‐carotene in the presence of α‐tocopherol and ascorbic acid and the oxygen concentration profiles in each phase. The model was able to effectively determine the appropriate amounts of lipophilic and hydrophilic antioxidants to prevent β‐carotene oxidation under various conditions.
Systematic review and meta-analysis of vagus nerve stimulation in the treatment of depression: Variable results based on study designs
Authors: Martin J.L.R. , Martín-Sánchez E.
Published: December 2011

Purpose:

To determine the efficacy of vagus nerve stimulation (VNS) for treatment of depression.

Methods:

We conducted a systematic review and meta-analysis of analytical studies. Efficacy was evaluated according to severity of illness and percentage of responders.

Results:

We identified 687 references. Of these, 14 met the selection criteria and were included in the review. The meta-analysis of efficacy for uncontrolled studies showed a significant reduction in scores at the Hamilton Depression Rating Scale endpoint, and the percentage of responders was 31.8% ([23.2% to 41.8%], P<0.001). However, the randomised control trial which covered a sample of 235 patients with depression, reported no statistically significant differences between the active intervention and placebo groups (OR=1.61 [95%CI 0.72 to 3.62]; P = 0.25). To study the cause of this heterogeneity, a meta-regression was performed. The adjusted coefficient of determination (R2Adj) was 0.84, which implies that an 84% variation in effect size across the studies was explained by baseline severity of depression (P<0.0001).

Conclusion:

Currently, insufficient data are available to describe VNS as effective in the treatment of depression. In addition, it cannot be ruled out that the positive results observed in the uncontrolled studies might have been mainly due to a placebo effect.
Recollement of homotopy categories and Cohen-Macaulay modules
Authors: Iyama Osamu , Kato Kiriko , Miyachi Jun-ichi
Published: December 2011

We study the homotopy category of unbounded complexes with bounded homologies and its quotient category by the homotopy category of bounded complexes. In the case of the homotopy category of finitely generated projective modules over an Iwanaga-Gorenstein ring, we show the existence of a new structure in the above quotient category, which we call a triangle of recollements. Moreover, we show that this quotient category is triangle equivalent to the stable module category of Cohen-Macaulay T2(R)-modules.
High-dose supplemental selenite to male Syrian hamsters fed hypercholesterolaemic diets altersLdlr,Abcg8andNpc1l1mRNA expression and lowers plasma cholesterol concentrations
Authors: Poirier Johanne , Cockell Kevin A. , Scoggan Kylie A. , Nimal Ratnayake W. M. , Rocheleau Hélène , Gruber Heidi , Swist Eleonora , Griffin Philip , Gagnon Claude , Kubow Stan
Published: December 2011

The aim of the present study was to elucidate possible cholesterol-lowering mechanism(s) of high-dose supplemental Se in the form of selenite, a known hypocholesterolaemic agent. Male Syrian hamsters (four groups, ten per group) were fed semi-purified diets for 4 weeks containing 0·1 % cholesterol and 15 % saturated fat with selenite corresponding to varying levels of Se: (1) Se 0·15 parts per million (ppm), control diet; (2) Se 0·85 ppm; (3) Se 1·7 ppm; (4) Se 3·4 ppm. Lipids were measured in the bile, faeces, liver and plasma. The mRNA expression of several known regulators of cholesterol homeostasis (ATP-binding cassette transportersg5(Abcg5) andg8(Abcg8), 7-hydroxylase, 3-hydroxy-3-methylglutaryl-coenzyme A reductase, LDL receptor (LdLr)and Nieman-Pick C1-like 1 protein (Npc1l1)) were measured in the liver and/or jejunum. Oxysterols including 24-(S)-hydroxycholesterol, 25-hydroxycholesterol and 27-hydroxycholesterol (27-OHC) were measured in the liver. Significantly lower total plasma cholesterol concentrations were observed in hamsters consuming the low (0·85 ppm) and high (3·4 ppm) Se doses. The two highest doses of Se resulted in decreased plasma LDL-cholesterol concentrations and increased mRNA levels of hepaticAbcg8,Ldlrand jejunalLdlr.Higher hepatic 27-OHC and TAG concentrations and lower levels of jejunalNpc1l1mRNA expression were noted in the 1·7 and 3·4 ppm Se-treated hamsters. Overall, Se-induced tissue changes in mRNA expression including increased hepaticAbcg8andLdlr, increased jejunalLdlrand decreased jejunalNpc1l1, provide further elucidation regarding the hypocholesterolaemic mechanisms of action of Se in the form of selenite.
A gestational low-protein diet represses p21WAF1/Cip1expression in the mammary gland of offspring rats through promoter histone modifications
Authors: Zheng Shasha , Rollet Michelle , Yang Kefeng , Pan Yuan-Xiang
Published: December 2011

Maternal exposure to environmental agents throughout pregnancy may change certain metabolic processes during the offspring's mammary gland development and alter the epigenome. This may predispose the offspring to breast cancer later in life. The purpose of the present study was to examine the effect of maternal protein restriction on the regulation of cyclin-dependent kinase inhibitor 1 (p21) gene expression in the mammary gland of rat offspring. Timed-mated Sprague–Dawley rats were fed one of the two isoenergetic diets, control (C, 18 % casein) or low protein (LP, 9 % casein), during gestation. Compared with the C group, LP offspring showed a decrease ofp21in the mammary gland at both the mRNA and protein levels. Chromatin immunoprecipitation assay demonstrated that the down-regulation ofp21transcription in LP offspring was associated with reduced acetylation of histone H3 and dimethylation of H3K4 within thep21promoter region, but was not associated with acetylation of histone H4 or histone methylation. DNA methylation analysis using bisulphite sequencing did not detect differences in methylation at thep21promoter between the offspring of the C and LP groups. We conclude that maternal protein restriction inhibitsp21gene expression in the mammary gland of offspring through histone modifications at the promoter region of thep21gene.
ON THE SPECTRA OF PISOT NUMBERS
Authors: ZAIMI TOUFIK
Published: December 2011

Let θ be a real number greater than 1, and let (()) be the fractional part function. Then, θ is said to be a Z-number if there is a non-zero real number λ such that ((λθn)) < for all n ∈ ℕ. Dubickas (A. Dubickas, Even and odd integral parts of powers of a real number, Glasg. Math. J., 48 (2006), 331–336) showed that strong Pisot numbers are Z-numbers. Here it is proved that θ is a strong Pisot number if and only if there exists λ ≠ 0 such that ((λα)) < for all$\alpha \in \{ \theta ^{n}\mid n\in \mathbb{N}\} \cup \{ \sum\nolimits_{n=0}^{N}\theta ^{n}\mid \mathit{\}N\in \mathbb{N}\}$. Also, the following characterisation of Pisot numbers among real numbers greater than 1 is shown: θ is a Pisot number ⇔ ∃ λ ≠ 0 such that$\Vert \lambda \alpha \Vert <\frac{1}{% 3}$for all$\alpha \in \{ \sum\nolimits_{n=0}^{N}a_{n}\theta ^{n}\mid$an ∈ {0,1}, N ∈ ℕ}, where ‖λα‖ = min{((λα)), 1 − ((λα))}.
ON FLATNESS COVERS OF CYCLIC ACTS OVER MONOIDS
Authors: QIAO HUSHENG , WANG LIMIN
Published: December 2011

The covers of cyclic acts over monoids were investigated by Mahmoudi and Renshaw (M. Mahmoudi and J. Renshaw, On covers of cyclic acts over monoids,Semigroup Forum77(2008), 325–338) and the authors posed some open problems. In the present paper, we give answers to their problems 1 and 5, and we also give a sufficient and necessary condition that a cyclic act has a weakly pullback flat cover.
UNIQUENESS OF COMPLETE HYPERSURFACES WITH BOUNDED HIGHER ORDER MEAN CURVATURES IN SEMI-RIEMANNIAN WARPED PRODUCTS
Authors: AQUINO C. P. , DE LIMA H. F.
Published: December 2011

In this paper, we deal with complete hypersurfaces immersed with bounded higher order mean curvatures in steady state-type spacetimes and in hyperbolic-type spaces. By applying a generalised maximum principle for the Yau's square operator [11], we obtain uniqueness results in each of these ambient spaces.
MULTIPLE POSITIVE SOLUTIONS OF RESONANT AND NON-RESONANT NON-LOCAL FOURTH-ORDER BOUNDARY VALUE PROBLEMS
Authors: WEBB J. R. L. , ZIMA M.
Published: December 2011

We study the existence of positive solutions for equations of the form

where 0 < ω < π, subject to various non-local boundary conditions defined in terms of the Riemann–Stieltjes integrals. We prove the existence and multiplicity of positive solutions for these boundary value problems in both resonant and non-resonant cases. We discuss the resonant case by making a shift and considering an equivalent non-resonant problem.
Shell morphology and relative growth variability of the invasive pearl oyster Pinctada radiata in coastal Tunisia
Authors: Bellaaj-Zouari Amel , Dkhili Souheil , Gharsalli Refka , Derbali Abdelkrim , Aloui-Bejaoui Nejla
Published: December 2011

The variability of shell morphology and relative growth of the invasive pearl oyster Pinctada radiata was studied within and among ten populations from coastal Tunisia using discriminant tests. Therefore, 12 morphological characters were examined and 34 metric and weight ratios were defined. In addition to the classic morphological characters, populations were compared by the thickness of the nacreous layer. Results of Duncan's multiple comparison test showed that the most discriminative ratios were the width of nacreous layer of right valve to the inflation of shell, the hinge line length to the maximum width of shell and the nacre thickness to the maximum width of shell. The analysis of variance revealed an important inter-population morphological variability. Both multidimensional scaling analysis and the squared Mahalanobis distances (D2) of metric ratios divided Tunisian P. radiata populations into four biogeographical groupings: the north coast (La Marsa); harbours (Hammamet, Monastir and Zarzis); the Gulf of Gabès (Sfax, Kerkennah Island, Maharès, Skhira and Djerba) and the intertidal area (Ajim). However, the Kerkennah Island population was discriminated by the squared Mahalanobis distances (D2) of weight ratios in an isolated group suggesting particular trophic conditions in this area. The allometric study revealed high linear correlation between shell morphological characters and differences in allometric growth among P. radiata populations. Unlike the morphological discrimination, allometric differentiation shows no clear geographical distinction. This study revealed that the pearl oyster P. radiata exhibited considerable phenotypic plasticity related to differences of environmental and/or ecological conditions along Tunisian coasts and highlighted the discriminative character of the nacreous layer thickness parameter.
Affective symptoms and intra-individual variability in the short-term course of cognitive functioning in bipolar disorder
Authors: Depp C. A. , Savla G. N. , de Dios L. A. Vergel , Mausbach B. T. , Palmer B. W.
Published: December 2011

Background

Few studies have examined the short-term course of cognitive impairments in bipolar disorder (BD). Key questions are whether trajectories in symptoms covary with cognitive function and whether BD is associated with increased intra-individual variability in cognitive abilities.

Method

Forty-two out-patients with BD and 49 normal comparison (NC) subjects were administered a battery of neuropsychological tests at baseline, 6, 12 and 26 weeks, along with concurrent ratings of depressive and manic symptom severity. Mixed-effects regressions were used to model relationships between time, diagnosis and symptom severity on composite cognitive performance. Within-person variance in cognitive functioning across time was calculated for each subject.

Results

BD patients had significantly worse performance in cognitive ability across time points, but both groups showed significant improvement in cognitive performance over repeated assessments (consistent with expected practice effects). BD was associated with significantly greater intra-individual variability in cognitive ability than NCs; within-person variation was negatively related to baseline cognitive ability in BD but not NC subjects. Changes in affective symptoms over time did not predict changes in cognitive ability.

Conclusions

Moderate changes in affective symptoms did not covary with cognitive ability in BD. The finding of elevated intra-individual variability in BD may reduce capacity to estimate trajectories of cognitive ability in observational and treatment studies.
A survey on spectral multiplicities of ergodic actions
Authors: DANILENKO ALEXANDRE I.
Published: December 2011

Given a transformationTof a standard measure space (X,μ), let ℳ(T) denote the set of spectral multiplicities of the Koopman operatorUTdefined in$L^2(X,\mu )\ominus \Bbb C$byUTf:=f∘T. In this survey paper we discuss which subsets of$\Bbb N\cup \{\infty \}$are realizable as ℳ(T) for variousT: ergodic, weakly mixing, mixing, Gaussian, Poisson, ergodic infinite measure-preserving, etc. The corresponding constructions are considered in detail. Generalizations to actions of Abelian locally compact second countable groups are also discussed.
“Keḥi kinnor” by Samuel Archivolti (d. 1611): A Wedding Ode with Hidden Messages
Authors: Harrán Don
Published: December 2011

Most research has a preliminary story embedded in earlier writings, which raise questions and spawn new inquiries conducive to new findings. The present study was born of other circumstances: I was asked by the directors of the early music group Ensemble Lucidarium if, for purposes of performance, I knew of a translation of Samuel Archivolti's Hebrew wedding ode “Keḥi kinnor” (Take a lyre). I had run across the ode in various listings, but was unfamiliar with any translation, so I suggested doing my own. That is where the problems began. To establish a clean reading for the poem, I consulted its manuscript and printed sources; to confront its verbal obscurities, and pinpoint its meanings, I traced its references to biblical and rabbinical literature; and to satisfy my own curiosity about how it was sung, I looked into the few recorded examples of its melodies. It follows that in this article, I shall be concerned mainly with semantics and music. Yet, to begin, I shall present some information about the author, sources, and prosody of the poem; and, to conclude, I shall compare it with other wedding odes of his and his contemporaries, and, in an epilogue, appraise its singularity.
The Significance of Form: R. Moses of Coucy's Reading Audience and HisSefer ha-Miẓvot
Authors: Galinsky Judah D.
Published: December 2011

Sefer miẓvot gadol(Semag) by the French Tosefist R. Moses of Coucy was a most influential halakhic work in medieval times. Originally titledSefer ha-miẓvot(The Book of Commandments), it was written in northern France in the first half of the thirteenth century and in many ways reveals the influence of Maimonides'Mishneh Torah. Indeed, to understand R. Moses of Coucy's legal project properly, it is important to comprehend the availability ofMishneh Torahin Europe at the time. Whereas Maimonides completed hisMishneh Torahcirca 1180, the work seems not to have reached the study halls of the French Tosefists before 1200. In this article, I explain R. Moses' purpose and program in writing hisSefer ha-miẓvot, examine the format he chose, and clarify who his presumptive reader, or readers, may have been.
“Serious” Talk
Authors: Shandler Jeffrey
Published: December 2011

Starting with its opening scene, A Serious Man offers a complex, provocative engagement with the role of storytelling in Jewish life, past and present. Many viewers have wondered how the film's “shtetl” prologue relates to its main story, set in Minneapolis in 1967. They have often speculated that there is some plot-driven relationship that they somehow missed. But the connection, by the filmmakers' own assertion, is not diegetic; rather, it is thematic, and storytelling figures strategically in articulating this link.
Open Secret in the Rearview Mirror
Authors: Wolfson Elliot R.
Published: December 2011

Much scholarly and popular attention has been centered on whether or not Menaḥem Mendel Schneerson, the seventh rebbe of the Ḥabad-Lubavitch dynasty, identified himself as the Messiah. While this interest is surely understandable, both doctrinally and anthropologically, in my judgment, it obscures the central question concerning the nature of the messianism he propagated. This line of inquiry might seem gratuitous for two reasons. First, his writings, discourses, and actions are replete with references to a personal Messiah, and since there is no evidence that he ever deviated from the strictures of rabbinic orthodoxy, there should be no reason to cast doubt on his explicit assertions. Second, a distinguishing feature of Ḥabad ideology, in consonance with the general drift of Ḥasidism, is the ostensible commitment to divulging mystical secrets, penimiyyut ha-torah, the spreading of the wellsprings outward (hafaṣat ma‘yanot ḥuṣah) to broadcast the mysteries that impart knowledge of divinity mandatory for proper worship. Prima facie, it would appear that Ḥabad breaks the code of esotericism upheld (in theory if not unfailingly in practice) by kabbalists through the centuries. This is surely the self-understanding sanctioned by the seventh rebbe, and it can be justifiably argued that he went to greater lengths than his predecessor and father-in-law, Yosef Yiṣḥaq Schneersohn—availing himself of the socioeconomic opportunities of the postwar American environment and making use of the instruments of technology—to accomplish the diffusion of the inwardness of the Torah.
Dietary habits of partly breast-fed and completely weaned infants at 9 months of age
Authors: Gondolf Ulla Holmboe , Tetens Inge , Michaelsen Kim Fleischer , Trolle Ellen
Published: December 2011

Objective

To test whether there are differences in diet diversity between children still being partly breast-fed at 9 months and those completely weaned at the same age.

Design

Cross-sectional study.

Setting

Cross-sectional study (SKOT cohort) in the area of Copenhagen, Denmark.

Subjects

Healthy term infants (n312) at 9 months of age (mean 9·1 (sd0·3) months).

Results

The infants partly breast-fed (n168) at 9 months had significantly lower body weight (P< 0·0001), were significantly shorter (P= 0·0022) and were introduced to complementary foods significantly later (P< 0·0001) than completely weaned infants (n141) of similar age. Furthermore, they had lower intake of energy, both in absolute amount (P< 0·0001) and per kilogram of body weight (P= 0·049). Significantly lower intakes of most energy-yielding nutrients, in absolute amounts and as energy percentages, were seen for the partly breast-fed compared with the completely weaned infants. These differences appear to be caused primarily by differences in the type and amount of milk consumed, as the energy derived from sources other than milk was similar except for fatty spread and vegetables as a side dish. Only small differences were found for absolute intakes of foods between feeding groups, although fatty spread had significantly higher intake rates and consumption (P= 0·031) among partly breast-fed compared with completely weaned infants.

Conclusions

At 9 months the infants partly breast-fed did not eat a less diversified diet compared with those completely weaned at the same age. Despite later introduction to complementary foods compared with the completely weaned, their intake of foods was similar and no delay in their progression towards the family foods was noted.
Epidemiological simulation modeling and spatial analysis for foot-and-mouth disease control strategies: a comprehensive review
Authors: Premashthira Sith , Salman Mo D. , Hill Ashley E. , Reich Robin M. , Wagner Bruce A.
Published: December 2011

Foot-and-mouth disease (FMD) is one of the most serious transboundary, contagious viral diseases of cloven-hoofed livestock, because it can spread rapidly with high morbidity rates when introduced into disease-free herds or areas. Epidemiological simulation modeling can be developed to study the hypothetical spread of FMD and to evaluate potential disease control strategies that can be implemented to decrease the impact of an outbreak or to eradicate the virus from an area. Spatial analysis, a study of the distributions of events in space, can be applied to an area to investigate the spread of animal disease. Hypothetical FMD outbreaks can be spatially analyzed to evaluate the effect of the event under different control strategies. The main objective of this paper is to review FMD-related articles on FMD epidemiology, epidemiological simulation modeling and spatial analysis with the focus on disease control. This review will contribute to the development of models used to simulate FMD outbreaks under various control strategies, and to the application of spatial analysis to assess the outcome of FMD spread and its control.
Disaggregated TIPS: the case for disaggregating inflation-linked bonds into bonds linked to narrower CPI components Slicing and Dicing TIPS
Authors: JENNINGS WILLIAM W.
Published: December 2011

Investors generally face inflation-linked obligations – a fact contributing to the popularity of TIPS and other inflation-linked bonds. With TIPS, one characterization of inflation, the Consumer Price Index, applies to all investors. Investors, however, face different inflation. To date, these heterogeneous needs have not been addressed by the inflation-linked marketplace. The paper describes the case for and mechanics of splitting TIPS into disaggregated TIPS matched to components of the Consumer Price Index. Disaggregated TIPS better address the risks of investors' specific real liabilities. A case study highlights disaggregated TIPS applicability to retirees with heavier post-retirement medical needs.
Asynchronous risk: retirement savings, equity markets, and unemployment
Authors: SELIGMAN JASON S. , WENGER JEFFREY B.
Published: December 2011

Retirement savings in defined contribution plans vary as a result of the timing and frequency of unemployment spells. We hypothesize that unemployment is coincident with negative shocks to equities prices, implying workers may systematically miss investment opportunities. First we match historic stock returns to unemployment hazards by gender, and earnings quartile. Next we test the relationship between unemployment, equity returns, and pension savings, by repeated simulation. Finally, we find that the timing of unemployment spells amplifies retirement savings losses on average for all worker-types in our analysis. Timing impacts are observed to be largest for high earnings workers and to increase with unemployment losses disproportionately.
Geochemical record of Holocene to Recent sedimentation on the Western Indus continental shelf, Arabian Sea
Authors: Limmer David R. , Böning Philipp , Giosan Liviu , Ponton Camilo , Köhler Cornelia M. , Cooper Matthew J. , Tabrez Ali R. , Clift Peter D.
Published: December 2011

We present a multiproxy geochemical analysis of two cores recovered from the Indus Shelf spanning the Early Holocene to Recent (<14 ka). Indus‐23 is located close to the modern Indus River, while Indus‐10 is positioned ∼100 km further west. The Holocene transgression at Indus‐10 was over a surface that was strongly weathered during the last glacial sea level lowstand. Lower Holocene sediments at Indus‐10 have higherεNdvalues compared to those at the river mouth indicating some sediment supply from the Makran coast, either during the deposition or via reworking of older sediments outcropping on the shelf. Sediment transport from Makran occurred during transgressive intervals when sea level crossed the mid shelf. The sediment flux from non‐Indus sources to Indus‐10 peaked between 11 ka and 8 ka. A hiatus at Indus‐23 from 8 ka until 1.3 ka indicates non‐deposition or erosion of existing Indus Shelf sequences. HigherεNdvalues seen on the shelf compared to the delta imply reworking of older delta sediments in building Holocene clinoforms. Chemical Index of Alteration (CIA), Mg/Al and Sr isotopes are all affected by erosion of detrital carbonate, which reduced through the Holocene. K/Al data suggest that silicate weathering peaked ca. 4–6 ka and was higher at Indus‐10 compared to Indus‐23. Fine‐grained sediments that make up the shelf have geochemical signatures that are different from the coarser grained bulk sediments measured in the delta plain. The Indus Shelf data highlight the complexity of reconstructing records of continental erosion and provenance in marine settings.
Fluid flow during slab unbending and dehydration: Implications for intermediate‐depth seismicity, slab weakening and deep water recycling
Authors: Faccenda Manuele , Gerya Taras V. , Mancktelow Neil S. , Moresi Louis
Published: December 2011

Subducting oceanic plates carry a considerable amount of water from the surface down to mantle depths and contribute significantly to the global water cycle. A part of these volatiles stored in the slab is expelled at intermediate depths (70–300 km) where dehydration reactions occur. However, despite the fact that water considerably affects many physical properties of rocks, not much is known about the fluid flow path and the interaction with the rocks through which volatiles flow in the slab interior during its dehydration. We performed thermomechanical models (coupled with a petrological database and with incompressible aqueous fluid flow) of a dynamically subducting and dehydrating oceanic plate. Results show that, during slab dehydration, unbending stresses drive part of the released fluids into the cold core of the plate toward a level of strong tectonic under‐pressure and neutral (slab‐normal) pressure gradients. Fluids progressively accumulate and percolate updip along such a layer forming, together with the upper hydrated layer near the top of the slab, a Double Hydrated Zone (DHZ) where intermediate‐depth seismicity could be triggered. The location and predicted mechanics of the DHZ would be consistent with seismological observations regarding Double Seismic Zones (DSZs) found in most subduction zones and suggests that hydrofracturing could be the trigger mechanism for observed intermediate‐depth seismicity. In the light of our results, the lower plane of the DSZ is more likely to reflect a layer of upward percolating fluid than a level of mantle dehydration. In our models, a 20–30 km thick DSZ forms in relatively old oceanic plates without requiring an extremely deep slab hydration prior to subduction. The redistribution of fluids into the slab interior during slab unbending also has important implications for slab weakening and the deep water cycle. We estimate that, over the whole of Earth's history, a volume of water equivalent to around one to two oceans can be stored in nominally anhydrous minerals of the oceanic lithosphere and transported to the transition zone by this mechanism, suggesting that mantle regassing could have been efficient even without invoking the formation of high pressure hydrous minerals.
Deformations of frozen droplets formed at −40°C
Authors: López María Laura , Ávila Eldo E.
Published: December 2011

The optical properties of cirrus clouds are frequently computed with respect to various ice‐crystal size distributions and shapes; small ice crystals are generally considered to be quasi‐spherical. This approximation can lead to significant errors in the analysis of the in‐situ microphysical data and also in the theoretical study of the radiative properties of cirrus clouds. Effective size and aspect ratio of the particles are the key parameters required to determine the optical parameters that are included in modeling and prediction of climate; their parameterizations need to be as accurate as possible. In this work, laboratory experiments were conducted to study the ice crystal shape formed from the freezing of water droplets at −40°C. Liquid and ice clouds were separately formed and sampled in a cloud chamber at −30 and −40°C, respectively. The effective water droplet diameter ranged from 8 to 20μm, while the effective ice particle diameter ranged from 8 to 30 μm. The average effective diameters were 11 μm for water drops and 14 μm for frozen droplets. The deformation of the frozen droplets was evident during inspection under microscope; bulges and spikes protuberances were found in many of the observed ice particles. The results show that the aspect ratio of the frozen droplets is 1.2.
On the formation of barrier layers and associated vertical temperature inversions: A focus on the northwestern tropical Atlantic
Authors: Mignot J. , Lazar A. , Lacarra M.
Published: December 2011

A unique barrier layer (BL) system in terms of persistence, extension, and associated subsurface temperature maximum is present seasonally in the northwestern tropical Atlantic. Based on climatological output of a general circulation ocean model, we show here that its development consists of two phases. In summer, the BL is relatively shallow and thin but subsurface temperature maxima are intense. The latter develop as a result of the specific seasonality of the freshwater discharge in this area, which limits the mixed layer to a very thin depth while the intense radiative heat flux penetrates significantly below, thereby heating the subsurface waters protected from air‐sea interactions and inducing a barrier layer between the mixed layer and the ocean interior. In winter, the BL development is due to a surface decrease in salinity associated with the surface freshwater capping, which decouples the pycnocline, and hence the winter mixed layer, from the thermocline. The mechanism is ubiquitous in the sense that it is very similar to that of other areas at the same latitude, as well as at high latitudes in regions of seasonal surface freshening. Results are discussed in the light of a simple linear equation linking the BL development to time evolution of Sea Surface Temperature and Sea Surface Salinity stratification.
Source and formation of secondary particulate matter in PM2.5 in Asian continental outflow
Authors: Feng J. L. , Guo Z. G. , Zhang T. R. , Yao X. H. , Chan C. K. , Fang M.
Published: December 2011

Fifty‐five 48‐h PM2.5 samples were collected from March 2003 to January 2004 at Changdao, a resort island in Bohai Sea/Yellow Sea in Northern China. Sulfate, nitrate and ammonium accounted for 54 ± 9% of the PM2.5 mass concentration (annual average 47 μg m−3) while organic matter and K+ contributed to 27 ± 7% and 7 ± 7% of the total mass, respectively. The ratios of SO42− to NO3− mass concentrations could be divided into two regimes and demarcated at nitrate concentration of 5 μg m−3. In the low NO3− regime, NO3−, SO42− and EC were well correlated to K+, and the estimated contributions of NO3−, SO42− and EC from biomass burning were 50 ± 27%, 38 ± 24% and 47 ± 27%, respectively. These correlations substantially decreased in the high NO3− regime reflecting fossil fuel combustion and formation of ammonium nitrate and the estimated contributions of NO3−, SO42− and EC from biomass burning were 16 ± 12%, 28 ± 18% and 27 ± 16%, respectively. In most samples, the equivalent ratios of total anion to total cation concentrations were greater than unity, suggesting that the aerosols were acidic. When [H+] > 0, a moderately good linear correlation of the estimated aerosol acidity [H+] with the water‐soluble organic carbon (WSOC) was observed with R2 = 0.70 and an increase of [H+] by 100 neq m−3 would increase 1.2 μg m−3 WSOC in PM2.5. When [H+] > 0, an increase of [H+] by 100 neq m−3 would increase 1.4 μg m−3 of secondary organic carbon (SOC) in PM2.5. Moreover, the correlation analysis result suggested that 60% of the estimated SOC (on average) in PM2.5 were water‐soluble.
Sixteen years of GOME/ERS‐2 total ozone data: The new direct‐fitting GOME Data Processor (GDP) version 5—Algorithm description
Authors: Van Roozendael M. , Spurr R. , Loyola D. , Lerot C. , Balis D. , Lambert J.‐C. , Zimmer W. , van Gent J. , van Geffen J. , Koukouli M. , Granville J. , Doicu A. , Fayt C. , Zehner C.
Published: December 2011

The Global Ozone Monitoring Instrument (GOME) was launched in April 1995 on ESA's ERS‐2 platform, and the GOME Data Processor (GDP) operational retrieval algorithm has produced total ozone columns since July 1995. We report on the new GDP5 spectral fitting algorithm used to reprocess the 16‐year GOME data record. Previous GDP total ozone algorithms were based on the DOAS method. In contrast, GDP5 uses a direct‐fitting algorithm without high‐pass filtering of radiances; there is no air mass factor conversion to vertical column amount. GDP5 includes direct radiative transfer simulation of earthshine radiances and Jacobians with respect to total ozone, albedo closure and other ancillary fitting parameters ‐ a temperature profile shift, and amplitudes for undersampling and Ring‐effect interference signals. Simulations are based on climatological ozone profiles extracted from the TOMS Version 8 database, classified by total column. GDP5 uses the high‐resolution Brion‐Daumont‐Malicet ozone absorption cross‐sections, replacing older GOME‐measured flight model data. The semi‐empirical molecular Ring correction developed for GDP4 has been adapted for direct fitting. Cloud preprocessing for GDP5 is done using updated versions of cloud‐correction algorithms OCRA and ROCINN. The reprocessed GOME GDP5 record maintains the remarkable long‐term stability of time series already achieved with GDP4. Furthermore, validation results show a clear improvement in the accuracy of the ozone product with reduced solar zenith angle and seasonal dependences, particularly in comparison with correlative observations from the ground‐based network of Brewer spectrophotometers.
MAARSY: The new MST radar on Andøya—System description and first results
Authors: Latteck R. , Singer W. , Rapp M. , Vandepeer B. , Renkwitz T. , Zecha M. , Stober G.
Published: December 2011

The Middle Atmosphere Alomar Radar System (MAARSY) on the North‐Norwegian island Andøya is a 53.5 MHz monostatic radar with an active phased array antenna consisting of 433 Yagi antennas. The 3‐element Yagi antennas are arranged in an equilateral triangle grid forming a circular aperture of approximately 6300 m2. Each individual antenna is connected to its own transceiver with independent phase control and a scalable power output up to 2 kW. This arrangement provides a very high flexibility of beam forming and beam steering with a symmetric radar beam of a minimum beam width of 3.6° allowing classical beam swinging operation as well as experiments with simultaneous multiple beams and the use of interferometric applications for improved studies of the Arctic atmosphere from the troposphere up to the lower thermosphere with high spatio‐temporal resolution. The installation of the antenna array was completed in August 2009. The radar control and data acquisition hardware as well as an initial expansion stage of 196 transceiver modules was installed in spring 2010 and upgraded to 343 transceiver modules in November 2010. The final extension to 433 transceiver modules has recently been completed in May 2011. Beside standard observations of tropospheric winds and Polar Mesosphere Summer Echoes, the first multi‐beam experiments using up to 97 quasi‐simultaneous beams in the mesosphere have been carried out in 2010 and 2011. These results provide a first insight into the horizontal variability of polar mesosphere summer and winter echoes with time resolutions between 3 and 9 minutes. In addition, first meteor head echo observations were conducted during the Geminid meteor shower in December 2010.
Continuous rainfall simulation: 2. A regionalized daily rainfall generation approach
Authors: Mehrotra Rajeshwar , Westra Seth , Sharma Ashish , Srikanthan Ratnasingham
Published: December 2011

This paper is the second of two in the current issue that presents a framework for simulating continuous (uninterrupted) rainfall sequences at both gaged and ungaged locations. The ultimate objective of the papers is to present a methodology for stochastically generating continuous subdaily rainfall sequences at any location such that the statistics at a range of aggregation scales are preserved. In this paper we complete the regionalized algorithm by adopting a rationale for generating daily sequences at any location by sampling daily rainfall records from “nearby” gages with statistically similar rainfall sequences.The approach consists of two distinct steps: first the identification of a set of locations with daily rainfall sequences that are statistically similar to the location of interest, and second the development of an algorithm to sample daily rainfall from those locations. In the first step, the similarity between all bivariate combinations of 2708 daily rainfall records across Australia were considered, and a logistic regression model was formulated to predict the similarity between stations as a function of a number of physiographic covariates. Based on the model results, a number of nearby locations with adequate daily rainfall records are identified for any ungaged location of interest (the “target” location), and then used as the basis for stochastically generating the daily rainfall sequences. The continuous simulation algorithm was tested at five locations where long historical daily rainfall records are available for comparison, and found to perform well in representing the distributional and dependence attributes of the observed daily record. These daily sequences were then used to disaggregate to a subdaily time step using the rainfall state‐based disaggregation approach described in the first paper, and found to provide a good representation of the continuous rainfall sequences at the location of interest.
Five dysfunctional telomeres predict onset of senescence in human cells
Authors: Kaul Zeenia , Cesare Anthony J , Huschtscha Lily I , Neumann Axel A , Reddel Roger R
Published: December 2011

Replicative senescence is accompanied by a telomere‐specific DNA damage response (DDR). We found that DDR+ telomeres occur spontaneously in early‐passage normal human cells and increase in number with increasing cumulative cell divisions. DDR+ telomeres at replicative senescence retain TRF2 and RAP1 proteins, are not associated with end‐to‐end fusions and mostly result from strand‐independent, postreplicative dysfunction. On the basis of the calculated number of DDR+ telomeres in G1‐phase cells just before senescence and after bypassing senescence by inactivation of wild‐type p53 function, we conclude that the accrual of five telomeres in G1 that are DDR+ but nonfusogenic is associated with p53‐dependent senescence.
A Golgi-localized MATE transporter mediates iron homoeostasis under osmotic stress in Arabidopsis
Authors: Seo Pil Joon , Park Jungmin , Park Mi-Jeong , Kim Youn-Sung , Kim Sang-Gyu , Jung Jae-Hoon , Park Chung-Mo
Published: December 2011

Iron is an essential micronutrient that acts as a cofactor in a wide variety of pivotal metabolic processes, such as the electron transport chain of respiration, photosynthesis and redox reactions, in plants. However, its overload exceeding the cellular capacity of iron binding and storage is potentially toxic to plant cells by causing oxidative stress and cell death. Consequently, plants have developed versatile mechanisms to maintain iron homoeostasis. Organismal iron content is tightly regulated at the steps of uptake, translocation and compartmentalization. Whereas iron uptake is fairly well understood at the cellular and organismal levels, intracellular and intercellular transport is only poorly understood. In the present study, we show that a MATE (multidrug and toxic compound extrusion) transporter, designated BCD1 (BUSH-AND-CHLOROTIC-DWARF 1), contributes to iron homoeostasis during stress responses and senescence in Arabidopsis. The BCD1 gene is induced by excessive iron, but repressed by iron deficiency. It is also induced by cellular and tissue damage occurring under osmotic stress. The activation-tagged mutant bcd1-1D exhibits leaf chlorosis, a typical symptom of iron deficiency. The chlorotic lesion of the mutant was partially recovered by iron feeding. Whereas the bcd1-1D mutant accumulated a lower amount of iron, the iron level was elevated in the knockout mutant bcd1-1. The BCD1 protein is localized to the Golgi complex. We propose that the BCD1 transporter plays a role in sustaining iron homoeostasis by reallocating excess iron released from stress-induced cellular damage.
Folded functional lipid-poor apolipoprotein A-I obtained by heating of high-density lipoproteins: relevance to high-density lipoprotein biogenesis
Authors: Jayaraman Shobini , Cavigiolio Giorgio , Gursky Olga
Published: December 2011

HDL (high-density lipoproteins) remove cell cholesterol and protect from atherosclerosis. The major HDL protein is apoA-I (apolipoprotein A-I). Most plasma apoA-I circulates in lipoproteins, yet ~5% forms monomeric lipid-poor/free species. This metabolically active species is a primary cholesterol acceptor and is central to HDL biogenesis. Structural properties of lipid-poor apoA-I are unclear due to difficulties in isolating this transient species. We used thermal denaturation of human HDL to produce lipid-poor apoA-I. Analysis of the isolated lipid-poor fraction showed a protein/lipid weight ratio of 3:1, with apoA-I, PC (phosphatidylcholine) and CE (cholesterol ester) at approximate molar ratios of 1:8:1. Compared with lipid-free apoA-I, lipid-poor apoA-I showed slightly altered secondary structure and aromatic packing, reduced thermodynamic stability, lower self-associating propensity, increased adsorption to phospholipid surface and comparable ability to remodel phospholipids and form reconstituted HDL. Lipid-poor apoA-I can be formed by heating of either plasma or reconstituted HDL. We propose the first structural model of lipid-poor apoA-I which corroborates its distinct biophysical properties and postulates the lipid-induced ordering of the labile C-terminal region. In summary, HDL heating produces folded functional monomolecular lipid-poor apoA-I that is distinct from lipid-free apoA-I. Increased adsorption to phospholipid surface and reduced C-terminal disorder may help direct lipid-poor apoA-I towards HDL biogenesis.
A novel glutaredoxin domain-containing peroxiredoxin ‘All1541’ protects the N2-fixing cyanobacterium Anabaena PCC 7120 from oxidative stress
Authors: Banerjee Manisha , Ballal Anand , Apte Shree K.
Published: December 2011

Prxs (peroxiredoxins) are ubiquitous thiol-based peroxidases that detoxify toxic peroxides. The Anabaena PCC 7120 genome harbours seven genes/ORFs (open reading frames) which have homology with Prxs. One of these (all1541) was identified to encode a novel Grx (glutaredoxin) domain-containing Prx by bioinformatic analysis. A recombinant N-terminal histidine-tagged All1541 protein was overexpressed in Escherichia coli and purified. Analysis with the protein alkylating agent AMS (4-acetamido-4′-maleimidyl-stilbene-2,2′-disulfonate) showed All1541 to form an intra-molecular disulfide bond. The All1541 protein used glutathione (GSH) more efficiently than Trx (thioredoxin) to detoxify H2O2. Deletion of the Grx domain from All1541 resulted in loss of GSH-dependent peroxidase activity. Employing site-directed mutagenesis, the cysteine residues at positions 50 and 75 were identified as peroxidatic and resolving cysteine residues respectively, whereas both the cysteine residues within the Grx domain (positions 181 and 184) were shown to be essential for GSH-dependent peroxidase activity. On the basis of these data, a reaction mechanism has been proposed for All1541. In vitro All1541 protein protected plasmid DNA from oxidative damage. In Anabaena PCC 7120, all1541 was transcriptionally activated under oxidative stress. Recombinant Anabaena PCC 7120 strain overexpressing All1541 protein showed superior oxidative stress tolerance to H2O2 as compared with the wild-type strain. The results suggest that the glutathione-dependent peroxidase All1541 plays an important role in protecting Anabaena from oxidative stress.
Preserving Cognitive Vitality in Older Adults
Authors: Schreck Janet Simon
Published: December 2011

As the population of older adults burgeons, preservation of cognitive vitality is quickly becoming a national public health concern. Speech-language pathologists are in a unique position to provide screening and prevention for cognitive-communication skills in the older adult population. In this article, I review medical and lifestyle factors currently associated with preservation of cognitive functioning. I also discuss the potential role of the speech-language pathologist with regard to screening, identification, and preventive intervention for this population.