Increased serum pigment epithelium derived factor levels in Type 2 diabetes patients

Serum PEDF levels (mean (S.D.)) were increased in 96 Type 2 diabetic vs. 54 non-diabetic subjects; 5.3 (2.8) vs. 3.2 (2.0)mug/ml, p

Rapid rise in Effective Sea-Level in southwest Bangladesh: Its causes and contemporary rates

Evidence is presented from three estuarine tide gauges located in the
Sundarban area of southwest Bangladesh of relative sea level rise
substantially in excess of the generally accepted rates from altimetry, as
well as previous tide-gauge analyses. It is proposed that the difference
arises from the use of relative mean sea level (RMSL) to characterise the
present and future coastal flood hazard, since RMSL can be misleading in
estuaries in which tidal range is changing. Three tide gauges, one located in
the uninhabited mangrove forested area (Sundarban) of southwest
Bangladesh, the others in the densely populated polder zone north of the
present Sundarban, show rates of increase in RMSL ranging from 2.8 mm
a-1 to 8.8 mm a-1. However, these trends in RMSL disguise the fact that high
water levels in the polder zone have been increasing at an average rate of
15.9 mm a-1 and a maximum of 17.2 mm a-1. In an area experiencing tidal
range amplification, RMSL will always underestimate the rise in high water
levels; consequently, as an alternative to RMSL, the use of trends in high
water maxima or ‘Effective Sea Level Rise’ (ESLR) is adopted as a more
strategic parameter to characterise the flooding hazard potential. The rate
of increase in ESLR is shown to be due to a combination of deltaic
subsidence, including sediment compaction, and eustatic sea level rise, but
principally as a result of increased tidal range in estuary channels recently
constricted by embankments. These increases in ESLR have been partially
offset by decreases in fresh water discharge in those estuaries connected
to the Ganges. The recognition of increases of the effective sea level in the
Bangladesh Sundarban, which are substantially greater than increases in
mean sea level, is of the utmost importance to flood management in this
low-lying and densely populated area.

Comment on "On the Uniqueness of Stable Marriage Matchings" [Economic Letters 69(1):1-8, 2000]

We prove with the help of a counterexample that Lemma 6 and Corollary 7 from Eeckhout [1] are incorrect.

Geochemical records of palaeoenvironmental controls on peat forming processes in the Mfabeni peatland, Kwazulu Natal, South Africa since the Late Pleistocene

The Mfabeni peatland is the only known sub-tropical coastal fen that transcends the Last Glacial Maximum (LGM). This ca. 10m thick peat sequence provides a continuous sedimentation record spanning from the late Pleistocene to present (basal age c. 47kcalyr BP). We investigated the paleaeoenvironmental controls on peat formation and organic matter source input at the Mfabeni fen by: 1) exploring geochemical records (mass accumulation rate, total organic carbon, carbon accumulation rate, δC, δN and C/N ratio) to delineate primary production, organic matter source input, preservation and diagenetic processes, and 2) employ these geochemical signatures to reconstruct the palaeoenvironmental conditions and prevailing climate that drove carbon accumulation in the peatland. We established that the Mfabeni peat sediments have undergone minimal diagenetic alteration. The peat sequence was divided into 5 linear sedimentation rate (LSR) stages indicating distinct changes in climate and hydrological conditions: LSR stage 1 (c. 47 to c. 32.2kcalyr BP): predominantly cool and wet climate with C4 plant assemblages, interrupted by two short warming events. LSR stage 2 (c. 32.2 to c. 27.6kcalyr BP): dry and windy climate followed by a brief warm and wet period with increased C4 sedge swamp vegetation. LSR stage 3 (c. 27.6 to c. 20.3kcalyr BP): initial cool and wet period with prevailing C4 sedge plant assemblage until c. 23kcalyr BP; then an abrupt change to dry and cool glacial conditions and steady increases in C3 grasses. LSR stage 4 (c. 20.3 to c. 10.4kcalyr BP): continuation of cool and dry conditions and strong C3 grassland signature until c. 15kcalyr BP, after which precipitation increases. LSR stage 5 (c. 10.4kcalyr BP to present): characterised by extreme fluctuations between pervasive wet and warm to cool interglacial conditions with intermittent abrupt millennial-scale cooling/drying events and oscillations between C3 and C4 plant assemblages. In this study we reconstructed a high-resolution record of local hydrology, bulk plant assemblage and inferred climate since the Late Pleistocene, which suggest an anti-phase link between Southern African and the Northern Hemisphere, most notably during Heinrich (5 to 2) and Younger Dryas events. © 2013 Elsevier B.V.

Dorsal and ventral stream mediated visual processing in genetic subtypes of Prader-Willi syndrome

Previous work has suggested that there are specific deficits in dorsal stream processing in a variety of developmental disorders. Prader-Willi syndrome (PWS) is associated with two main genetic subtypes, deletion and disomy. Relative strengths in visual processing are shown in PWS, although these strengths may be specific to the deletion subtype. We investigated visual processing in PWS using an adapted Simon task which contrasted location (dorsal stream) and shape identity (ventral stream) tasks. Compared to a group of typically developing children, children with PWS deletion showed a greater degree of impairment in the dorsal stream task than in the ventral stream task, a pattern similar to that shown in a group of boys with Fragile-X syndrome. When matched on a measure of non-verbal ability, children with PWS disomy showed the opposite pattern with better performance in the location compared to the shape task, although these task performance asymmetries may have been linked to executive control processes. It is proposed that children with PWS deletion show a relative strength in visual processing in the ventral stream along with a specific deficit in dorsal stream processing. In contrast, children with PWS disomy show neither effect. (C) 2009 Published by Elsevier Ltd.

Identification of damping in a bridge using a moving instrumented vehicle

In recent years, there has been a significant increase in the number of bridges which are being instrumented and monitored on an ongoing basis. This is in part due to the introduction of bridge management systems designed to provide a high level of protection to the public and early warning if the bridge becomes unsafe. This paper investigates a novel alternative; a low-cost method consisting of the use of a vehicle fitted with accelerometers on its axles to monitor the dynamic behaviour of bridges. A simplified half-car vehicle-bridge interaction model is used in theoretical simulations to test the effectiveness of the approach in identifying the damping ratio of the bridge. The method is tested for a range of bridge spans and vehicle velocities using theoretical simulations and the influences of road roughness, initial vibratory condition of the vehicle, signal noise, modelling errors and frequency matching on the accuracy of the results are investigated.

Enrichment of low-abundance proteins from bovine and porcine serum samples for proteomic studies

One of the main applications of serum proteomics is the identification of new biomarkers for animal disease or animal production. However, potential obstacles to these studies are the poor performance of affinity serum depletion methods based on human antigens when using animal samples, and loss of minor serum components bound to albumin and other proteins. In the present study, we have analyzed the efficiency and reproducibility of the ProteoMiner® beads with bovine and porcine serum samples, and compared to a traditional immunoaffinity-based albumin and IgG depletion system specific for human samples. The ProteoMiner kit is based on the use of a combinatorial peptide binding library and intends to enrich low-abundance proteins.

Potentially inappropriate prescribing among older people in the United Kingdom

Background: Potentially inappropriate prescribing (PIP) in older people is associated with increases in morbidity, hospitalisation and mortality. The objective of this study was to estimate the prevalence of and factors associated with PIP, among those aged ≥70 years, in the United Kingdom, using a comprehensive set of prescribing indicators and comparing these to estimates obtained from a truncated set of the same indicators.

Methods: A retrospective cross-sectional study was carried out in the UK Clinical Practice Research Datalink (CPRD), in 2007. Participants included those aged ≥ 70 years, in CPRD. Fifty-two PIP indicators from the Screening Tool of Older Persons Potentially Inappropriate Prescriptions (STOPP) criteria were applied to data on prescribed drugs and clinical diagnoses. Overall prevalence of PIP and prevalence according to individual STOPP criteria were estimated. The relationship between PIP and polypharmacy (≥4 medications), comorbidity, age, and gender was examined. A truncated, subset of 28 STOPP criteria that were used in two previous studies, were further applied to the data to facilitate comparison.

Results: Using 52 indicators, the overall prevalence of PIP in the study population (n = 1,019,491) was 29%. The most common examples of PIP were therapeutic duplication (11.9%), followed by use of aspirin with no indication (11.3%) and inappropriate use of proton pump inhibitors (PPIs) (3.7%). PIP was strongly associated with polypharmacy (Odds Ratio 18.2, 95% Confidence Intervals, 18.0-18.4, P < 0.05). PIP was more common in those aged 70–74 years vs. 85 years or more and in males. Application of the smaller subset of the STOPP criteria resulted in a lower PIP prevalence at 14.9% (95% CIs 14.8-14.9%) (n = 151,598). The most common PIP issues identified with this subset were use of PPIs at maximum dose for > 8 weeks, NSAIDs for > 3 months, and use of long-term neuroleptics.

Conclusions: PIP was prevalent in the UK and increased with polypharmacy. Application of the comprehensive set of STOPP criteria allowed more accurate estimation of PIP compared to the subset of criteria used in previous studies. These findings may provide a focus for targeted interventions to reduce PIP.

Cytotoxic assessment of the regulated, co-existing mycotoxins aflatoxin B1, fumonisin B1 and ochratoxin, in single, binary and tertiary mixtures

Aflatoxin B1 (AFB1), ochratoxin A (OTA) and fumonisin B1 (FB1) are contaminants which have been shown to regularly co-occur in a range of foods. However, only a small number of studies have evaluated the interactive effect of binary and tertiary mycotoxins. The present study evaluated the effects of low levels of each mycotoxin in combination at their EU regulatory limits. Toxic effect with respect to cell viability was measured by MTT and neutral red assays, assessing mitochondria and lysosome integrities respectively. Individual toxicity showed that OTA (10 μg/ml) was the most cytotoxic mycotoxin in all three cell lines studied (caco-2, MDBK and raw 264.7). Binary combinations were cytotoxic to the MDBK cell line in the order [OTA/FB1] > [AFB1/FB1] > [AFB1/OTA], whilst all effects observed were classified as being additive. Tertiary combinations of AFB1, FB1 and OTA at the EU regulatory limits were tested and not found to exhibit measurable cytotoxicity in MDBK, caco-2 or raw 264.7 cells. However by increasing these concentrations above the legal limits to OTA (3 μg/ml), FB1 (8 μg/ml) and AFB1 (1.28 μg/ml), cytotoxicity was observed with up to 26% reduction in cell viability and synergistic effects were evident with regard to mitochondrial integrity. © 2014 Elsevier Ltd. All rights reserved.

Type Synthesis of 3-DOF Multi-Mode Translational/Spherical Parallel Mechanisms with Lockable Joints

A 3-DOF (degrees-of-freedom) multi-mode translational/spherical PM (parallel mechanism) with lockable joints is a novel reconfigurable PM. It has both 3-DOF spatial translational operation mode and 3-DOF spherical operation mode. This paper presents an approach to the type synthesis of translational/spherical PMs with lockable joints. Using the proposed approach, several 3-DOF translational/spherical PMs are obtained. It is found that these translational/spherical PMs do not encounter constraint singular configurations and self-motion of sub-chain of a leg during reconfiguration. The approach can also be used for synthesizing other classes of multi-mode PMs with lockable joints, multi-mode PMs with variable kinematic joints, partially decoupled PMs, and reconfigurable PMs with a reconfigurable platform.

Cyanoacrylate glue versus suture in peripheral nerve reanastomosis

OBJECTIVE: To assess the effectiveness of n-butyl-2-cyanoacrylate glue compared with microsuturing technique in peripheral nerve reanastomosis in rats.

STUDY DESIGN: Fourteen young adult white rats were used. Bilateral sciatic neurotomies were performed in 12 of them and then reanastomosed with 3 epineural microsutures in the right side (study group G1) and with n-butyl-2-cyanoacrylate glue in the left side (study group G2). On the remaining 2 rats (control group G3), sham surgery was done on both sides. Biopsies were harvested 12 weeks after surgery and examined under light microscope using Osmic acid stains. The number of nerve fibers was counted in the distal and proximal nerve segments, and the results were analyzed and compared in all groups.

RESULTS: Adequate regeneration with no anastomotic ruptures was seen 12 weeks after surgery in G1 and G2. The histomorphometric assessment showed no statistically significant difference (P = .960) in the neurotization index of G1 (89.01%) compared with G2 (88.97%). There was a significant (P = .001) reduction in the mean number of axon counts distal to the repair in G1 (271.3) and G2 (272.8) compared with that of the proximal segments of each study group (304.6 and 303, respectively, as well as to that of G3 (348.5).

CONCLUSION: Both n-butyl-2-cyanoacrylate adhesive and 3-microsuture techniques showed comparable neurotization indices and were equally adequate to stabilize the nerve during regeneration period.

Distal volcanic ash layers in the Lateglacial Interstadial (GI-1): problems of stratigraphic discrimination

A new Icelandic ash layer has been detected in mid-Interstadial sediments in a number of Scottish Lateglacial sequences and has been named the Penifiler Tephra. It is rhyolitic in composition and possesses a chemistry, which is similar to the Borrobol Tephra of early Lateglacial Interstadial age, which also occurs in a number of these same sequences. Where the Borrobol Tephra has been identified in these sequences it consistently exhibits a diffuse distribution accompanied in some cases by stratigraphic bimodality. A number of sedimentological and taphonomic factors are considered in order to account for this distribution. One possibility is that these distributions are produced by taphonomic factors. Another possibility is that the Borrobol Tephra may not be the product of a single Icelandic eruption, but of two events closely spaced in time. In at least two of the sequences investigated in this study, basaltic shards were found in association with the Penifiler and Borrobol tephras, suggesting either a basaltic phase associated with these eruptions, or coincident eruptions from a separate basaltic volcanic centre. The discovery of the new Penifiler Tephra makes a contribution to the regional tephrostratigraphic framework, and provides an additional isochron for assessing the synchroneity of palaeoenvironmental changes during the Interstadial. The true stratigraphic nature and age of the Borrobol Tephra, however, remains unresolved and, therefore, its use as an isochron is more problematic. The possible occurrence of basaltic populations may strengthen correlations with basaltic tephras recently detected in the NGRIP ice-core.

The statistical significance of randomized controlled trial results is frequently fragile: A case for a Fragility Index

Objectives

A P-value <0.05 is one metric used to evaluate the results of a randomized controlled trial (RCT). We wondered how often statistically significant results in RCTs may be lost with small changes in the numbers of outcomes.

Study Design and Setting

A review of RCTs in high-impact medical journals that reported a statistically significant result for at least one dichotomous or time-to-event outcome in the abstract. In the group with the smallest number of events, we changed the status of patients without an event to an event until the P-value exceeded 0.05. We labeled this number the Fragility Index; smaller numbers indicated a more fragile result.

Results

The 399 eligible trials had a median sample size of 682 patients (range: 15-112,604) and a median of 112 events (range: 8-5,142); 53% reported a P-value <0.01. The median Fragility Index was 8 (range: 0-109); 25% had a Fragility Index of 3 or less. In 53% of trials, the Fragility Index was less than the number of patients lost to follow-up.

Conclusion

The statistically significant results of many RCTs hinge on small numbers of events. The Fragility Index complements the P-value and helps identify less robust results. 

Sets of multiplicity and closable multipliers on group algebras

We undertake a detailed study of the sets of multiplicity in a second countable locally compact group G and their operator versions. We establish a symbolic calculus for normal completely bounded maps from the space B(L-2(G)) of bounded linear operators on L-2 (G) into the von Neumann algebra VN(G) of G and use it to show that a closed subset E subset of G is a set of multiplicity if and only if the set E* = {(s,t) is an element of G x G : ts(-1) is an element of E} is a set of operator multiplicity. Analogous results are established for M-1-sets and M-0-sets. We show that the property of being a set of multiplicity is preserved under various operations, including taking direct products, and establish an Inverse Image Theorem for such sets. We characterise the sets of finite width that are also sets of operator multiplicity, and show that every compact operator supported on a set of finite width can be approximated by sums of rank one operators supported on the same set. We show that, if G satisfies a mild approximation condition, pointwise multiplication by a given measurable function psi : G -> C defines a closable multiplier on the reduced C*-algebra G(r)*(G) of G if and only if Schur multiplication by the function N(psi): G x G -> C, given by N(psi)(s, t) = psi(ts(-1)), is a closable operator when viewed as a densely defined linear map on the space of compact operators on L-2(G). Similar results are obtained for multipliers on VN(C).

Quantum yield measurements for the photocatalytic oxidation of Acid Orange 7 (AO7) and reduction of 2,6-dichloroindophenol (DCIP) on transparent TiO2 films of various thickness

This work comprises the photoactivity assessment of transparent sol–gel TiO2 coatings of various thickness using two test systems. The initial rates of both photocatalytic reactions, namely the oxidative bleaching of Acid Orange 7 (AO7) and the reductive bleaching of 2,6-dichlorindophenol (DCIP) increase linearly with increasing titania film thickness as well as with increasing absorbed light flux. The latter work revealed quantum yields (QY) of 0.19% and 92% for the AO7 and DCIP test system, respectively. The low QY for the AO7 oxidation is due to the combination of a slow irreversible reduction of oxygen and also for the oxidation of AO7, thus favouring the high efficiency for electron–hole recombination that is typical for aqueous organic pollutants. In contrast, the very high QY for the photocatalysed reduction of DCIP is due to the presence of a vast excess of glycerol which traps the photogenerated holes efficiently and so allow time for the slower reduction of dye to take place. Furthermore, the oxidation of glycerol results in the generation of highly reducing R-hydroxyalkyl radicals that are able to also reduce DCIP. As a consequence of this ‘current doubling’ effect, the observed QY (92%) is much higher than the apparent theoretical value of 50%.