bluuebunny/crossref_metadata_2025 huggingface dataset:
Primary fatty amides in plasma associated with brain amyloid burden, hippocampal volume, and memory in the European Medical Information Framework for Alzheimer's Disease biomarker discovery cohort
Authors: Kim Min , Snowden Stuart , Suvitaival Tommi , Ali Ashfaq , Merkler David J. , Ahmad Tahmina , Westwood Sarah , Baird Alison , Proitsi Petroula , Nevado‐Holgado Alejo , Hye Abdul , Bos Isabelle , Vos Stephanie , Vandenberghe Rik , Teunissen Charlotte , ten Kate Mara , Scheltens Philip , Gabel Silvy , Meersmans Karen , Blin Olivier , Richardson Jill , De Roeck Ellen , Sleegers Kristel , Bordet Régis , Rami Lorena , Kettunen Petronella , Tsolaki Magda , Verhey Frans , Sala Isabel , Lléo Alberto , Peyratout Gwendoline , Tainta Mikel , Johannsen Peter , Freund‐Levi Yvonne , Frölich Lutz , Dobricic Valerija , Engelborghs Sebastiaan , Frisoni Giovanni B. , Molinuevo José L. , Wallin Anders , Popp Julius , Martinez‐Lage Pablo , Bertram Lars , Barkhof Frederik , Ashton Nicholas , Blennow Kaj , Zetterberg Henrik , Streffer Johannes , Visser Pieter J. , Lovestone Simon , Legido‐Quigley Cristina
Published: May 2019

Introduction

A critical and as‐yet unmet need in Alzheimer's disease (AD) is the discovery of peripheral small molecule biomarkers. Given that brain pathology precedes clinical symptom onset, we set out to test whether metabolites in blood associated with pathology as indexed by cerebrospinal fluid (CSF) AD biomarkers.

Methods

This study analyzed 593 plasma samples selected from the European Medical Information Framework for Alzheimer's Disease Multimodal Biomarker Discovery study, of individuals who were cognitively healthy (n = 242), had mild cognitive impairment (n = 236), or had AD‐type dementia (n = 115). Logistic regressions were carried out between plasma metabolites (n = 883) and CSF markers, magnetic resonance imaging, cognition, and clinical diagnosis.

Results

Eight metabolites were associated with amyloid β and one with t‐tau in CSF, these were primary fatty acid amides (PFAMs), lipokines, and amino acids. From these, PFAMs, glutamate, and aspartate also associated with hippocampal volume and memory.

Discussion

PFAMs have been found increased and associated with amyloid β burden in CSF and clinical measures.
Response invalidity in empirical research: Causes, detection, and remedies
Authors: Edwards Jeffrey R.
Published: May 2019

Research in behavioral operations management and related areas relies heavily on self‐report measures. The utility of such measures depends on the extent to which the responses are valid, meaning they correspond to the thoughts and beliefs of respondents with regard to the phenomena under study. Response validity is undermined when respondents are unwilling or unable to provide adequate responses to survey questions, an issue that has generated an array of methods for screening and evaluating survey data and dealing with dubious responses. This article uses the work of Abbey and Meloy (2017) as a point of departure to examine the causes, detection, and remedies of response invalidity. The article concludes with recommendations for future research that treats response validity and its dimensions as methods factors that should be formally incorporated into statistical models.
CLUSTER STRUCTURES ON HIGHER TEICHMULLER SPACES FOR CLASSICAL GROUPS
Authors: LE IAN
Published: May 2019

Let $S$ be a surface, $G$ a simply connected classical group, and $G^{\prime }$ the associated adjoint form of the group. We show that the moduli spaces of framed local systems ${\mathcal{X}}_{G^{\prime },S}$ and ${\mathcal{A}}_{G,S}$, which were constructed by Fock and Goncharov [‘Moduli spaces of local systems and higher Teichmuller theory’, Publ. Math. Inst. Hautes Études Sci.103 (2006), 1–212], have the structure of cluster varieties, and thus together form a cluster ensemble. This simplifies some of the proofs in that paper, and also allows one to quantize higher Teichmuller space, which was previously only possible when $G$ was of type $A$.
Microdroplet nucleation by dissolution of a multicomponent drop in a host liquid
Authors: Tan Huanshu , Diddens Christian , Mohammed Ali Akash , Li Junyi , Versluis Michel , Zhang Xuehua , Lohse Detlef
Published: May 2019

Multicomponent liquid drops in a host liquid are very relevant in various technological applications. Their dissolution or growth dynamics is complex. Differences in solubility between the drop components combined with the solutal Marangoni effect and natural convection contribute to this complexity, which can be even further increased in combination with the ouzo effect, i.e. the spontaneous nucleation of microdroplets due to composition-dependent miscibilities in a ternary system. The quantitative understanding of this combined process is important for applications in industry, particularly for modern liquid–liquid microextraction processes. In this work, as a model system, we experimentally and theoretically explore water–ethanol drops dissolving in anethole oil. During the dissolution, we observed two types of microdroplet nucleation, namely water microdroplet nucleation in the surrounding oil at drop mid-height, and oil microdroplet nucleation in the aqueous drop, again at mid-height. The nucleated oil microdroplets are driven by Marangoni flows inside the aqueous drop and evolve into microdroplet rings. A one-dimensional multiphase and multicomponent diffusion model in combination with thermodynamic equilibrium theory is proposed to predict the behaviour of spontaneous emulsification, i.e. microdroplet nucleation, that is triggered by diffusion. A scale analysis together with experimental investigations of the fluid dynamics of the system reveals that both the solutal Marangoni flow inside the drop and the buoyancy-driven flow in the host liquid influence the diffusion-triggered emulsification process. Our work provides a physical understanding of the microdroplet nucleation by dissolution of a multicomponent drop in a host liquid.
Beyond the breaking point? Survey satisficing in conjoint experiments
Authors: Bansak Kirk , Hainmueller Jens , Hopkins Daniel J. , Yamamoto Teppei
Published: May 2019

Recent years have seen a renaissance of conjoint survey designs within social science. To date, however, researchers have lacked guidance on how many attributes they can include within conjoint profiles before survey satisficing leads to unacceptable declines in response quality. This paper addresses that question using pre-registered, two-stage experiments examining choices among hypothetical candidates for US Senate or hotel rooms. In each experiment, we use the first stage to identify attributes which are perceived to be uncorrelated with the attribute of interest, so that their effects are not masked by those of the core attributes. In the second stage, we randomly assign respondents to conjoint designs with varying numbers of those filler attributes. We report the results of these experiments implemented via Amazon's Mechanical Turk and Survey Sampling International. They demonstrate that our core quantities of interest are generally stable, with relatively modest increases in survey satisficing when respondents face large numbers of attributes.
Response of diamine oxidase and other plasma copper biomarkers to various dietary copper intakes in the rat and evaluation of copper absorption with a stable isotope
Authors: Feillet-Coudray C. , Coudray C. , Bayle D. , Rock E. , Rayssiguier Y. , Mazur A.
Published: May 2019

There is a lack of agreement on index of Cu status and reliable and sensitive biomarkers are still required. The purpose of this present work was to assess in rats the sensitivity of diamine oxidase (DAO) activity, a recently proposed biomarker, to modifications in dietary Cu intake in comparison with other plasma biomarkers of Cu status. We also evaluated the effect of Cu dietary level on Cu and Zn intestinal absorption. Results showed that plasma Cu and plasma caeruloplasmin were significantly decreased at day 8 compared with the control group (7·4 mg Cu/kg diet) while DAO activity was significantly decreased at day 12 of the deficient diet (0·61 mg Cu/kg diet). Cu supplementation (35 mg Cu/kg diet) had no effect on any of the studied biomarkers of Cu status. In Cu-deficient rats plasma Cu and DAO activities were normalized 4 d after return to the control diet while caeruloplasmin was normalized later, at day 11. Apparent absorption values (%) of total Cu or65Cu isotope were significantly increased in the Cu-deficient rats compared with the other groups and similar in the control and the Cu-supplemented groups. The urinary excretion of total Cu or65Cu isotope were increased in the Cu-supplemented group compared with the other two groups. Both apparent absorption and urinary excretion of total Zn or67Zn isotope remained unchanged in the three experimental groups. In conclusion, DAO activity seemed to be less sensitive to Cu deficiency than plasma Cu or caeruloplasmin concentrations. The present study also showed a significant increase in Cu intestinal absorption with dietary Cu restriction but no decrease with Cu supplementation in the rat.
Intestinal metabolism of rye lignans in pigs
Authors: Glitsø L. V. , Mazur W. M. , Adlercreutz H. , Wähälä K. , Mäkelä T. , Sandström B. , Knudsen K. E. Bach
Published: May 2019

To study the intestinal metabolism of lignans, the concentrations of plant and mammalian lignans in intestinal digesta sampled along the intestinal tract of pigs were determined by isotope dilution GC–MS. The pigs were fed rye-bread diets made from either whole rye-grains or rye-grain milling fractions enriched in pericarp–testa, aleurone or endosperm cells. The content and characteristics of dietary fibre varied between diets and had been shown to induce different colon fermentation patterns. As the metabolism of lignans depends on the action of the intestinal flora, we tested whether the rye-bread diets influence the metabolism of lignans. In the ileum, the lignans were mainly present as conjugated plant lignans, which were determined only when the analytical procedure included a hydrolysis step. High recovery of dietary lignans in the ileum may indicate that the lignans enter the enterohepatic circulation. In addition, two to three times the intake of lignans were recovered in the faeces when the diets had a high content of dietary fibre suggesting underestimation of plant lignans in the diet. Most of the plant lignans disappeared from the intestinal tract between the terminal ileum and the caecum. The intestinal concentrations and the disappearance of lignans correlated with the content of lignans in the diet, being highest on the pericarp–testa diet and lowest on the endosperm diet. No effect of fermentation pattern on the intestinal metabolism of lignans was observed. The lignans were liberated from the pericarp–testa diet although the plant cell walls remained largely undegraded.
Fruit and vegetable availability among ten European countries:how does it compare with the ‘five-a-day’ recommendation?
Authors: Naska Androniki , Vasdekis Vassilis G. S. , Trichopoulou Antonia , Friel Sharon , Leonhäuser Ingrid U. , Moreiras Olga , Nelson Michael , Remaut Anne M. , Schmitt Anette , Sekula Wlodzimierz , Trygg Kerstin U. , Zajkás Gábor ,   DAFNE I and II projects of the European Commission
Published: May 2019

Recasting the role of fruit and vegetables (F&V) in the diet, and planning national and international campaigns to enhance their consumption are major public health service objectives. The present study seeks to describe F&V availability patterns in ten European countries and examine compliance with current recommendations. The mean and median F&V availability (g/person per d) was estimated based on household budget survey data retrieved from the Data Food Networking (DAFNE) databank. Low F&V consumers were identified based on WHO international recommendations (minimum combined F&V intake of about 400 g/person per d) and current conservative guidelines of a minimum daily intake of three portions of vegetables and two portions of fruit. Considerable disparities in F&V availability were found among the surveyed European populations. Only in Mediterranean countries did the mean daily population intake clearly exceed combined F&V recommendations. Dietary patterns were positively skewed in all populations studied, on account of the presence of exceptionally high values among segments of the populations. Moreover, the correlation was unexpectedly weak between the proportion of low fruit and low vegetable consumers (Spearman's correlation coefficient +0·18). More than 50 % of the households in the surveyed populations are likely to consume less than the recommended daily vegetable intake of three portions, and this applies even to the two Mediterranean populations. The efficiency of F&V promoting strategies may be enhanced if F&V are addressed separately; furthermore, interventions that would specifically focus on vegetables are probably needed.
Diets enriched with cereal brans or inulin modulate protein kinase C activity and isozyme expression in rat colonic mucosa
Authors: Pajari Anne-Maria , Oikarinen Seija , Gråsten Soile , Mutanen Marja
Published: May 2019

The role of dietary fibres in colon carcinogenesis is controversial. To elucidate the mechanisms by which different dietary fibre sources may affect colonic tumour development, we studied the effects of diets enriched with cereal brans or inulin on protein kinase C (PKC) activity and isozyme expression in rat colon. Male Wistar rats (twelve per group) were fed one of the following AIN-93G-based diets () for 4 weeks: a non-fibre high-fat diet or one of the four high-fat diets supplemented with either rye, oat or wheat bran or inulin at 100 g/kg diet. The fat concentration (20 g/100 g) and fatty acid composition of the non-fibre high-fat diet was designed to approximate that in a typical Western-type diet. In the proximal colon, rats fed the inulin diet had a significantly higher membrane PKC activity and a higher membrane PKC δ level than rats fed the non-fibre diet (P<0·05). In the distal colon, rats fed the inulin and oat bran diets had a higher total PKC activity and a higher membrane PKC β2 level than rats fed the wheat-bran diet. Rats in the non-fibre and wheat-bran groups had the lowest concentrations of luminal diacylglycerol. In conclusion, feeding of wheat bran resulted in low distal PKC activity and expression of PKC β2, a PKC isozyme related to colonic cell proliferation and increased susceptibility for colon carcinogenesis, which may explain in part the protective effect of wheat bran against tumour development in a number of experimental colon cancer studies. The increase in PKC activity and PKC β2 expression by feeding inulin may be a drawback of inulin as a functional food.
Cocoa powder enhances the level of antioxidative activity in rat plasma
Authors: Baba Seigo , Osakabe Naomi , Natsume Midori , Yasuda Akiko , Takizawa Toshio , Nakamura Tetsuo , Terao Junji
Published: May 2019

The aims of the present study were to determine the level of (-)-epicatechin (EC) and its metabolites in rat plasma after oral administration of cocoa powder and to evaluate the protective effect of cocoa powder in terms of suppressing the oxidation of plasma components. Rats were orally administered 1 g cocoa powder/kg body weight, containing 7·80 mg EC, and their blood was collected before administration and at designated time intervals thereafter. The EC and its metabolites in plasma were treated with β-glucuronidase and/or sulfatase, then analysed by HPLC and by liquid chromatography–MS. Several EC-related compounds were detected in plasma such as free EC, and glucuronide, sulfate, and glucuronide–sulfate conjugates of non-methylated or methylated EC. All EC metabolites showed a maximum concentration in plasma at 30–60 min post-administration. Glucuronide conjugates of both non-methylated and methylated EC were found in high concentration in plasma. Moreover, administration of cocoa powder significantly reduced the accumulation of lipid peroxides in plasma and significantly reduced the consumption of α-tocopherol in plasma oxidized by treatment with 2,2′-azobis-(2-amidinopropane) dihydrochloride (AAPH (25 mmol/l)) or CuSO4 (100 μmol/l) compared with that in the case of plasma obtained before administration. The total EC concentration in plasma was negatively correlated with the level of accumulation of lipid peroxides in plasma oxidized by treatment with AAPH (25 mmol/l) and was positively correlated with the level of residual α-tocopherol in plasma oxidized by treatment with CuSO4 (100 μmol/l). These results indicate that EC in cocoa powder was absorbed from the digestive tract, that various conjugated forms of EC were generated in the digestive tract and distributed to the plasma, and that these enhanced the antioxidative activity of plasma.
Potato and high-amylose maize starches are not equivalent producers of butyrate for the colonic mucosa
Authors: Martin Lucile J. M. , Dumon Henri J. W. , Lecannu Gérard , Champ Martine M. J.
Published: May 2019

Portal appearance of short-chain fatty acids (SCFA) produced from fermentation of three different resistant starch (RS) sources (raw potato starch, high-amylose maize starch and retrograded high-amylose maize starch) was investigated in pigs. The catheterization technique coupled with determination of portal blood flow was used to estimate SCFA uptake by the colonic mucosa. Our hypothesis was that these three RS were not equivalent butyrate providers for the colonic mucosa and that butyrate uptake would therefore be different after in vivo fermentation of each starch. The starches induced different patterns of appearance of SCFA in the portal blood; raw potato starch was the only RS source to show a significant appearance of butyrate in the portal blood. Thus, uptake of butyrate by the colonic mucosa apparently differed between starches. This finding suggests that butyrate uptake does not only depend on the flow of butyrate appearing in the lumen. Indeed, for unexplained reasons, utilization of butyrate by the colonic mucosa appeared to be less efficient when the butyrate was produced from fermentation of potato starch than when it was produced from fermentation of the other RS sources.
Lymphocyte metallothionein mRNA responds to marginal zinc intake in human volunteers
Authors: Allan Adrian K. , Hawksworth Gabrielle M. , Woodhouse Leslie R. , Sutherland Barbara , King Janet C. , Beattie John H.
Published: May 2019

Marginal Zn deficiency is thought to be prevalent in both developed and developing countries. However, the extent of Zn deficiency is not known, due to the lack of a reliable diagnostic indicator. Blood plasma and erythrocyte concentrations of metallothionein (MT) reflect Zn status, but measurement of MT is dependent on the availability of sensitive immunoassays. Our aim was to show whether measurement of T lymphocyte MT-2A mRNA, using a competitive reverse transcriptase (RT)–polymerase chain reaction (PCR) assay, could indicate Zn status in human subjects in a residential Zn-depletion study. In the study, the Zn intake of seven volunteers was maintained at 13·7 mg/d for 5 weeks (baseline) followed by 4·6 mg/d for 10 weeks (marginal intake) and then 13·7 mg/d (repletion) for 5 weeks. The quantitative assay was developed using standard techniques and concentrations of MT-2A mRNA were normalized by reference to β-actin mRNA which was also measured by competitive RT–PCR assay. An alternative method of measuring the PCR product using capillary electrophoresis with laser-induced fluorescence detection was also evaluated. There was considerable inter-individual variation in MT-2A mRNA concentration and the mean level at the end of the baseline period was 10·3 (SE 3·7) fg MT-2A mRNA/pg β-actin mRNA, which then decreased by 64 % during the low Zn intake period. After repletion, MT-2A mRNA returned to baseline concentrations. In contrast, plasma Zn was unchanged by marginal Zn intake or repletion. The effect of low Zn in all individuals was consistent. We conclude that this assay is a sensitive method of evaluating marginal changes in dietary Zn intake.
Influence of different dietary fats on triacylglycerol deposition in rat adipose tissue
Authors: Perona Javier S. , Portillo María P. , Teresa Macarulla M. , Tueros Ana I. , Ruiz-Gutiérrez Valentina
Published: May 2019

It has been demonstrated that triacylglycerol (TAG) mobilization from adipose tissue is selective and depends on fatty acid (FA) chain length, unsaturation and positional isomerism. The present study was performed to determine the influence of dietary fat on the composition of TAG stored in rat perirenal and subcutaneous adipose tissues. These results may provide information on the susceptibility of stored TAG to hydrolysis and further mobilization, and may help to establish an interrelationship between dietary composition and the FA efflux from adipose tissue. TAG molecular species and FA composition were determined by HPLC and GLC respectively. No significant differences were found in either FA or TAG composition between perirenal and subcutaneous adipose depots. The major FA in the dietary fats were present in the adipose tissues of the animals; in most cases, in similar proportions. However, differences were found between dietary and adipose tissue content of minor FA, which suggests that dietary FA composition is altered between ingestion and deposition in adipose tissue. The TAG molecular species of rat adipose tissue were enriched with the FA characteristic of each dietary fat. Dietary sunflower oil was responsible for enrichment with the most polar TAG. This finding may suggest easier mobilization of stored TAG. In conclusion, the process of fatty acid and TAG deposition in rat adipose tissue is selective, and depends on the composition of the diet.
Cross-over study of the influence of bicarbonate-rich mineral water on urinary composition in comparison with sodium potassium citrate in healthy male subjects
Authors: Keßler Torsten , Hesse Albrecht
Published: May 2019

Urine volume is the greatest risk factor for nephrolithiasis. High fluid intake is the first general advice given to stone-forming patients for the prevention of their recurrence. The aim of the present study was to evaluate the influence of bicarbonate-rich mineral water (1715 mg bicarbonate/l) on urinary-stone risk factors in comparison with sodium potassium citrate, a well-established treatment for urinary stones. The mineral water and sodium potassium citrate were administered in equimolar concentrations, with respect to the alkali load. All investigations were carried out in healthy male subjects aged 23–38 years. The study followed a cross-over design. All subjects received a standardized diet during the cross-over phase, which was formulated according to the dietary recommendations of the German Society of Nutrition (). On the loading day of the cross-over phase, fruit tea was substituted for either mineral water or sodium potassium citrate dissolved in fruit tea. The treatment offered during the second part of the cross-over phase was continued for a 4-week follow-up under normal dietary conditions. During the cross-over phase, there was a significant increase in urinary pH (P<0·001). There was also a significant increase in the excretion of citric acid (P<0·01), a decrease in the excretion of oxalic acid, and therefore a decrease in the relative supersaturations for calcium oxalate and uric acid. In the follow-up phase also, the relative supersaturations decreased and there were beneficial effects on the other urinary variables. The effect of the bicarbonate-rich mineral water was similar to that of the sodium potassium citrate, which suggests that it could be useful in the prevention of the recurrence of calcium oxalate and uric acid stones.
An evaluation of EDTA compounds for iron fortification of cereal-based foods
Authors: Hurrell Richard F. , Reddy Manju B. , Burri Joseph , Cook James D.
Published: May 2019

Fe absorption was measured in adult human subjects consuming different cereal foods fortified with radiolabelled FeSO4, ferrous fumarate or NaFeEDTA, or with radiolabelled FeSO4or ferric pyrophosphate in combination with different concentrations of Na2EDTA. Mean Fe absorption from wheat, wheat–soyabean and quinoa (Chenopodium quinoa) infant cereals fortified with FeSO4or ferrous fumarate ranged from 0·6 to 2·2 %. For each infant cereal, mean Fe absorption from ferrous fumarate was similar to that from FeSO4(absorption ratio 0·91–1·28). Mean Fe absorption from FeSO4-fortified bread rolls was 1·0 % when made from high-extraction wheat flour and 5·7 % when made from low-extraction wheat flour. Fe absorption from infant cereals and bread rolls fortified with NaFeEDTA was 1·9–3·9 times greater than when the same product was fortified with FeSO4. Both high phytate content and consumption of tea decreased Fe absorption from the NaFeEDTA-fortified rolls. When Na2EDTA up to a 1:1 molar ratio (EDTA:Fe) was added to FeSO4-fortified wheat cereal and wheat–soyabean cereal mean Fe absorption from the wheat cereal increased from 1·0 % to a maximum of 5·7 % at a molar ratio of 0·67:1, and from the wheat–soyabean cereal from 0·7 % to a maximum of 2·9 % at a molar ratio of 1:1. Adding Na2EDTA to ferric pyrophosphate-fortified wheat cereal did not significantly increase absorption (P>0·05). We conclude that Fe absorption is higher from cereal foods fortified with NaFeEDTA than when fortified with FeSO4or ferrous fumarate, and that Na2EDTA can be added to cereal foods to enhance absorption of soluble Fe-fortification compounds such as FeSO4.
Dietary conjugated linoleic acid mixture affects the activity of intestinal acyl coenzyme A: cholesterol acyltransferase in hamsters
Authors: Thomas Yeung Chi Hang , Yang Lin , Huang Yu , Wang Jun , Chen Zhen-Yu
Published: May 2019

The present study was designed to study the mechanisms by which dietary conjugated linoleic acids (CLA) decrease serum cholesterol. Hamsters were fed a semi-synthetic diet containing 1 g cholesterol/kg diet with or without supplementation with 20 g linoleic acid (LA) and 20 g CLA/kg diet. After 8 weeks, serum fasting total cholesterol (TC) and triacylglycerol (TG) were significantly lower in the LA-supplemented and CLA-supplemented groups compared with those of the control (CTL) hamsters. In contrast to LA, CLA significantly lowered hepatic cholesterol but it increased the level of adipose tissue cholesterol, suggesting that the hypocholesterolaemic mechanism of CLA is different from that of LA. CLA decreased the activity of intestinal acyl CoA:cholesterol acyltransferase (ACAT) whereas LA had no effect on this enzyme. Consequently, CLA supplementation increased the faecal excretion of total neutral sterols, but it had no or little effect on the faecal acidic sterols. If the ACAT is associated with cholesterol absorption, the part of mechanisms by which CLA decreases serum cholesterol may involve down-regulation of intestinal ACAT activity.
THE STRUCTURE OF PLAUTUS’ MENAECHMI
Authors: Lowe Christopher
Published: May 2019

Widely different views have been held concerning the structure of Plautus’ Menaechmi. On the one hand, the sequence of misunderstandings arising from the presence in the same city of a pair of identical twins with the same name has been likened to clockwork and attributed in essentials to an unknown Greek dramatist. On the other hand, E. Stärk has stressed features of the play which are typical of improvised comedy and put forward the bold theory that it was constructed by Plautus himself, following traditions of pre-literary Italic drama but using stock motifs of Greek New Comedy. I wish to suggest that the truth lies between these extreme positions.
Integrated gas field development: The Anjum story
Authors: Hollman F.J.
Published: May 2019

In contrast to oil field development, gas field development requires tight integration of subsurface, surface and economic issues due to the difficulty of storing surplus produced gas and the large effect of the back-pressures in a surface network on the individual well performance. As a major gas supplier the Shell Group, and in particular NAM, has extensive experience in this field.

The gas production from onshore fields in the North Friesland area is a recent NAM development. A 10 million cubic meter per day LTS gas treatment installation located near the village of Anjum came on stream in 1997. Production initially started from 3 wells in 2 fields to deliver gas to the Gasunie grid at Grijpskerk. The total area comprises 10 fields and 4 remaining prospects and is planned to be fully developed by the year 2001, using wet gas pipelines to route the production to either the Anjum LTS installation or the Grijpskerk SilicaGel installation.

The Rotliegend reservoirs in this part of the Netherlands are very heterogeneous and require a more detailed subsurface simulation than feasible with the standard NAM tool for gas field development (GENREM). In addition, the area is close to the Waddenzee and based on extensive ecological research, NAM uses a stringent, self-imposed ecological constraint, whilst evaluating the development plans for this area. Detailed subsidence studies have been run using subsidence-modeling tools, which run under a software user-interface called FrontEnd, an in-house development by the Shell Group. Also running under this interface is an application for gas field development called Gas Field Planning Tool (GFPT). GFPT combines a detailed subsurface simulator with a surface simulator using a development planning module, which handles economic and operational aspects of the integrated model. Lastly, the interface gives access to a powerful command language and a mathematical toolbox, which can be used to define almost any missing functionality.

Making use of the flexibility offered by the FrontEnd interface and with help from available expertise in RTS (Shell Rijswijk), an integrated GFPT model was built, which not only incorporates operational and economic constraints, but also does optimization and subsidence analysis. The model is used to evaluate all development options and scenarios for this area in a consistent manner. Therefore, all proposed development plans are optimized within all applied constraints whether they are related to surface, subsurface, economic, or environmental aspects.

Production history and well performance are very close to those predicted by these detailed models, which will allow accurate prediction of future field performance and subsidence.
Subsidence, tremors and society
Authors: Gussinklo H.J. , Haak H.W. , Quadvlieg R.C.H. , Schutjens P.M.F.M. , Vogelaar L.
Published: May 2019

The province of Groningen is flat and level, lying at an elevation close to sea level. The area is intensely cultivated and water table levels are a matter of concern. When the size of the Groningen gasfield was recognized in the sixties, it was realized, that substantial subsidence might occur at the surface affecting a large area.

Intensive studies were performed over time to predict future subsidence. These studies are supported by theoretical and experimental research in Shell since the 1950’s concerning reservoir compaction and related surface subsidence. To monitor reservoir compaction and surface subsidence on a regular basis, an extensive monitoring program was set up by NAM. The program comprises leveling surveys, GPS measurements, measurements of shallow formation compaction and in-situ reservoir compaction.

In Groningen weak earthquakes have occurred since 1991 at irregular intervals. A multidisciplinary study from 1991–1993 on the relationship between gas production and earthquakes in the northern part of the Netherlands, combined with further studies concluded, that under certain circumstances these earthquakes may result from gas production. Monitoring is carried out through a seismic observation network with borehole sensors and locally installed accelerometers.

Because of the expected impact of subsidence induced by gas production on surface water management, an Agreement was concluded between the Province of Groningen and NAM.

In line with the 1983 Agreement the ‘Commissie Bodemdaling’ was founded, in which both NAM and the Province of Groningen are represented. On the basis of NAM predictions and actual measurements this Committee determines, what measures are to be taken to prevent, minimize or to correct for effects of gas production induced surface subsidence.
Environmental conditions and paleowind directions at the end of the Weichselian Late Pleniglacial recorded in aeolian sediments and geomorphology (Twente, Eastern Netherlands)
Authors: van Huissteden Ko (J.) , Schwan Jacques C.G. , Bateman Mark D.
Published: May 2019

The Late weichselian Pleniglacial wind regime in the eastern Netherlands is reconstructed by means of landform and sedimentological analysis. This analysis involves aeolian and fluvial landforms in the Dinkel river valley in the Twente region. The aeolian deposits considered here date from the Last Glacial Maximum (approximately 22 ka) to the start of the Belling Interstadial at 14.7 ka.

A major event in this period is the formation of a cryoturbation level caused by permafrost degradation, overlain by an erosional hiatus dated between 21 and 17 ka. Both features are attributed to a period of warmer and moister climate, causing permafrost degradation and erosion by surficial runoff. Thereafter aeolian activity prevailed under relatively arid conditions. A deflation surface was formed, the Beuningen Gravel Bed. This deflation surface is present in many Weichselian sections in the Netherlands and the adjacent parts of Belgium and Germany. The deflation occurred concurrently with deposition of coversand at other places.

The morphology of the coversand-landscape in the Dinkel valley was controlled by the relief of the pre-existing floodplain and the wind pattern. Coversand ridges consisting of low dunes accumulated near the margins of the active channel belt. Relatively thick sand sheets occur in the leesides of the ridges, thin sand sheets are found at greater distance.

Mainly westerly sand-transporting winds operated during winter and summer. In winter aeolian deposition occurred by frequent and strong easterly winds also. On the smallest, local scale, the pattern of deposition was determined by the topography and moisture of the receiving surface.

Coversand deposition came to an end with the formation of a sand sheet under relatively warm and less arid conditions. Coversand deposition continued into the Belling Interstadial; colonization of the coversand surface by vegetation probably has been delayed by nutrient-poor conditions.
The climate in The Netherlands during the Younger Dryas and Preboreal: means and extremes obtained with an atmospheric general circulation model
Authors: Renssen H.
Published: May 2019

The shift from the coldYounger Dryas phase to the relatively warm Pre-boreal at~l 1.5 thousand years BP occurred within 50 calendar years and represents a clear example of rapid climate warming. Geologists and palaeo-ecologists have extensively studied the impact of this shift on the environment in The Netherlands. The global atmospheric general circulation model of the Max-Planck-Institute for Meteorology is applied to perform simulations of the Younger Dryas and Pre-boreal climates. Here detailed results are presented for the grid-cell representing The Netherlands, providing quantified estimates of climatic means and extremes for both periods. The results suggest that the Younger Dryas climate was characterised by cold winters (temperatures regularly below -20 °C) and cool summers (13-14 °C), with a high inter-annual variability, strong fluctuations in temperature, frequent storms and snowfall from September to May. The Pre-boreal climate was a ‘continental’ version of present-day climate, with cooler winters, warmer summers (~2 °C difference) and more snowfall, but lower wind speeds. Also, the Pre-boreal climate was wetter than the present and Younger Dryas climates. The main driving factors were the low temperatures of the partly sea-ice covered N Atlantic Ocean and the insolation that was very different from today, with more incoming solar radiation during summer (+30W/m2) and less during winter (-10W/m2).The presented detailed results could be valuable for interpreting palaeo-environmental records and for modelling studies on sedimentological processes during the Late Quaternary.
Vertebrate track bed stratigraphy of the Röt and basal Lower Muschelkalk (Anisian) of Winterswijk (East Netherlands)
Authors: Diedrich C.
Published: May 2019

The 35.5 m thick Anisian section of theWinterswijkse Steen- en Kalkgroeve (Eastern Netherlands) comprises the Upper Röt (Upper Röt Claystone Member) to the basal Lower Muschelkalk (Oolith Member). In the section 15 terrestrial or marine influenced parasequences are recognized. A fourth order sequence shows the increasing marine influence. New marker beds, ten vertebrate track beds, three bone beds and cephalopod remains have been documented. This enabled correlation to other sections in NW Germany. The tracks found in the Winterswijkse Steen- en Kalkgroeve at the boundary Röt/Lower Muschelkalk are linked to the oldest known vertebrate skeleton remains of the Germanic Basin. It is the first time that the exact stratigraphic position of these vertebrate remains has been established. In the terrestrial influenced section of the Winterswijkse Steen- en Kalkgroeve, the well preserved vertebrate track ways and vertebrate fauna will be of international importance and will provide new data of theTriassic carbonate tidal flat megatracksite concept and reptiles living in this environment.
Laser-diffraction and pipette-method grain sizing of Dutch sediments: correlations for fine fractions of marine, fluvial, and loess samples
Authors: Buurman P. , Pape Th. , Reijneveld J.A. , de Jong F. , van Gelder E.
Published: May 2019

To evaluate correlations between silt and clay fractions determined by pipette method and laser diffraction, samples from Dutch fine marine, fluvial, and loess deposits were analysed by both methods. For fluvial deposits, correlations for fractions <2 and >50 μm were excellent (R2 > 0.95), those for 2–4, 4–8, 16–32 and 32–50 μm were satisfactory (R2 = 0.80 – 0.95), while that for the fraction 8–16 μm had an R2 of only 0.68. For marine deposits, correlations for <2 and >50 μm were in the same range, but those of all other fractions except 8–16 μm were lower. In the loess samples, correlations for all but the 8–16 μm fraction were unsatisfactory. Laser diffraction gave 42% of pipette clay in marine samples, and 62% in fluvial and loess samples if regressions are forced through 0. Sand fractions detected by laser diffraction were 107% of the sieve fraction in marine samples, and 99% in the fluvial samples. Correlations for fractions smaller than reference size are generally better than those for individual size fractions. Both the 2 μm and the 50 μm boundary cause problems in the comparison. The first because of platy shape of clay minerals, and the second due to both a change in method in the pipette/sieving procedure, and to non-sphericity of particles. Apparently, correlations for clay- and silt-size fractions obtained by pipette method and laser diffraction will be different for each type of sediment.
A Gelfand-Phillips space not containing l1 whose dual ball is not weak * sequentially compact
Authors: Josefson Bengt
Published: May 2019

A set D in a Banach space E is called limited if pointwise convergent sequences of linear functionals converge uniformly on D and E is called a GP-space (after Gelfand and Phillips) if every limited set in E is relatively compact. Banach spaces with weak * sequentially compact dual balls (W*SCDB for short) are GP-spaces and l1 is a GP-space without W*SCDB. Disproving a conjecture of Rosenthal and inspired by James tree space, Hagler and Odell constructed a class of Banach spaces ([HO]-spaces) without both W*SCDB and subspaces isomorphic to l1. Schlumprecht has shown that there is a subclass of the [HO]-spaces which are also GP-spaces. It is not clear however if any [HO]-construction yields a GP-space—in fact it is not even clear that W*SCDB[lrarr ]GP-space is false in general for the class of Banach spaces containing no subspace isomorphic to l1. In this note the example of Hagler and Odell is modified to yield a GP-space without W*SCDB and without an isomorphic copy of l1.
Genes, folate and homocysteine in embryonic development
Authors: Rosenquist Thomas H. , Finnell Richard H.
Published: May 2019

Population-based studies of human pregnancies show that periconceptional folate supplementation has a significant protective effect for embryos during early development, resulting in a significant reduction in developmental defects of the face, the neural tube, and the cono-truncal region of the heart. These results have been supported by experiments with animal models. An obvious quality held in common by these three anatomical regions is that the normal development of each region depends on a set of multi-potent cells that originate in the mid-dorsal region of the neural epithelium. However, the reason for the sensitive dependence of these particular cells on folic acid for normal development has not been obvious, and there is no consensus about the biological basis of the dramatic rescue with periconceptional folate supplementation. There are two principal hypotheses for the impact of folate insufficiency on development; each of these hypotheses has a micronutrient component and a genetic component. In the first hypothesis the effect of low folate is direct, limiting the availability of folic acid to cells within the embryo itself; thus compromising normal function and limiting proliferation. The second hypothetical effect is indirect: low folate disrupts methionine metabolism; homocysteine increases in the maternal serum; homocysteine induces abnormal development by inhibiting the function of N-methyl-D-aspartate (NMDA) receptors in the neural epithelium. There are three general families of genes whose level of expression may need to be considered in the context of these two related hypotheses: folate-receptor genes; genes that regulate methionine– homocysteine metabolism; NMDA-receptor genes.
Phenotypic plasticity more essential to maintaining variation in host-attachment behaviour than evolutionary trade-offs in a facultatively parasitic mite
Authors: Durkin Emily S. , Luong Lien T.
Published: May 2019

A prevailing hypothesis for the evolution of parasitism posits that the fitness benefits gained from parasitic activity results in selection for and fixation of parasitic strategies. Despite the potential fitness advantage of parasitism, facultative parasites continue to exhibit genetic variation in parasitic behaviour in nature. We hypothesized that evolutionary trade-offs associated with parasitic host-attachment behaviour maintain natural variation observed in attachment behaviour. In this study, we used replicate lines of a facultatively parasitic mite, previously selected for increased host-attachment behaviour to test whether increased attachment trades off with mite fecundity and longevity, as well as the phenotypic plasticity of attachment. We also tested for potential correlated changes in mite morphology. To test for context-dependent trade-offs, mite fecundity and longevity were assayed in the presence or absence of a host. Our results show that selected and control mites exhibited similar fecundities, longevities, attachment plasticities and morphologies, which did not provide evidence for life history trade-offs associated with increased attachment. Surprisingly, phenotypic plasticity in attachment was maintained despite directional selection on the trait, which suggests that phenotypic plasticity likely plays an important role in maintaining attachment variation in natural populations of this facultative parasite.
Cytokine profile in first-episode psychosis, unaffected siblings and community-based controls: the effects of familial liability and childhood maltreatment
Authors: Corsi-Zuelli Fabiana , Loureiro Camila Marcelino , Shuhama Rosana , Fachim Helene Aparecida , Menezes Paulo Rossi , Louzada-Junior Paulo , Mondelli Valeria , Del-Ben Cristina Marta
Published: May 2019

Background

Inflammation is a possible biological mechanism underlying the association between childhood maltreatment and psychosis. Previous investigations on this regard were mainly conducted on chronic schizophrenia and lacked control for confounders. We aim to investigate the role of familial liability, childhood maltreatment and recent stress in determining cytokine abnormalities at the onset of psychosis.

Methods

We recruited 114 first-episode psychosis (FEP) patients, 57 unaffected biological siblings of FEP patients, and 251 community-based controls. Plasma cytokines (IL-1β, IL-6, TNF-α, IFN-γ, IL-4, IL-10 and TGF-β) were measured and differences across the groups analysed after adjusting for potential confounders.

Results

FEP had a higher pro- and anti-inflammatory cytokine profile (IL-1β, IL-6, TNF-α, IL-10 and TGF-β), which was not observed in unaffected siblings. Siblings presented decreased IL-1β when compared with patients and controls. Childhood maltreatment was associated with higher levels of TGF-β in both patients and siblings when compared with controls. Physical childhood abuse was associated with increased levels of TGF-β in FEP patients but with decreased levels in controls. Other childhood maltreatment subtypes or recent stressors did not affect cytokine levels in any of the groups.

Conclusions

Normal or reduced cytokines in siblings represent possibly a protective factor and suggest that the identified inflammatory profile in FEP can be a real pathophysiological component of psychosis. Experience of childhood maltreatment may contribute as long-term immune priming for the TGF-β pathway, and increased levels of this cytokine in both patients and siblings exposed to childhood maltreatment point to a possible biological candidate of familial risk for psychosis.
Theory and practice in language teacher education
Authors: Ur Penny
Published: May 2019

We often hear language teachers say ‘Don't confuse me with theories, just give me practical ideas I can take into the classroom’. Many teacher educators and researchers, on the other hand, believe that (research-based) theory is more important, and should be used and implemented by practitioners. This paper will propose an approach to the use of theory and practice in teacher education that may help to resolve this dissonance. After some preliminary definitions and clarification of some common confusions, it is suggested thattheoryandpracticein the context of language teaching are not polar opposites, but points on a continuum: any statement or guideline about teaching can be, more or less, practical or theoretical. The rest of the paper will focus on the questions how the various types of published theories or teacher theorizing can contribute to professional expertise, what is the place of practical tips or recipes, and how all these can be used or combined in teacher education courses to bring about optimal learning by novice teachers, or increased expertise on the part of the more experienced ones.