bluuebunny/crossref_metadata_2025 huggingface dataset:
Is it a mottled duck? The key is in the feathers
Authors: Bielefeld Ronald R. , Engilis Andrew , Feddersen Jamie C. , Eadie John M. , Tringali Michael D. , Benedict R. Joseph
Published: July 2016

The Florida mottled duck (Anas fulvigula fulvigula) is threatened by introgression through hybridization with feral mallards (A. platyrhynchos). An essential component in managing this threat is the ability to accurately distinguish mottled ducks from mallards and hybrids in the wild. We provide a genetically cross‐validated phenotype key that accurately identifies mottled ducks. We collected data on structural and plumage traits from museum specimens of Florida, USA, mottled ducks and mallards to identify morphological traits useful in this process. We performed extensive comparisons and discriminant function analysis to identify traits informative in distinguishing the 2 species. We used these traits to preliminarily assign 168 contemporary birds as putative mottled duck, mallard, or hybrid. We collected tissue samples from each contemporary specimen and amplified and genotyped associated DNA. We used microsatellite markers to determine posterior probability species assignments for the 168 specimens. We then performed recursive partitioning of phenotypic traits and posterior genotype assignments to create identification keys based on the most informative traits separating mottled ducks from mallards and hybrids. Finally, we cross‐validated the keys by comparing assignments made using the key to those from genotyping for 339 wild ducks. The keys were >90% accurate, which suggests that their adoption will increase the ability of managers to address the threat of hybridization by mallards by allowing mottled ducks to be distinguished from other ducks in Florida. Our research provides a methodology to develop genetically cross‐validated identification keys for other species threatened by genetic introgression. © 2016 The Wildlife Society.
Modelling timed reactive systems from natural-language requirements
Authors: Carvalho Gustavo , Cavalcanti Ana , Sampaio Augusto
Published: July 2016

At the very beginning of system development, typically only natural-language requirements are documented. As an informal source of information, however, natural-language specifications may be ambiguous and incomplete; this can be hard to detect by means of manual inspection. In this work, we present a formal model, named data-flow reactive system (DFRS), which can be automatically obtained from natural-language requirements that describe functional, reactive and temporal properties. A DFRS can also be used to assess whether the requirements are consistent and complete. We define two variations of DFRS: a symbolic and an expanded version. A symbolic DFRS (s-DFRS) is a concise representation that inherently avoids an explicit representation of (possibly infinite) sets of states and, thus, the state space-explosion problem. We use s-DFRS as part of a technique for test-case generation from natural-language requirements. In our approach, an expanded DFRS (e-DFRS) is built dynamically from a symbolic one, possibly limited to some bound; in this way, bounded analysis (e.g., reachability, determinism, completeness) can be performed. We adopt the s-DFRS as an intermediary representation from which models, for instance, SCR and CSP, are obtained for the purpose of test generation. An e-DFRS can also be viewed as the semantics of the s-DFRS from which it is generated. In order to connect such a semantic representation to established ones in the literature, we show that an e-DFRS can be encoded as a TIOTS: an alternative timed model based on the widely used IOLTS and ioco. To validate our overall approach, we consider two toy examples and two examples from the aerospace and automotive industry. Test cases are independently created and we verify that they are all compatible with the corresponding e-DFRS models generated from symbolic ones. This verification is performed mechanically with the aid of the NAT2TEST tool, which supports the manipulation of such models.
The Yield of Fever, Inflammatory Markers and Ultrasound in the Diagnosis of Acute Cholecystitis: A Validation of the 2013 Tokyo Guidelines
Authors: Naidu K. , Beenen E. , Gananadha S. , Mosse C.
Published: July 2016

Background

Each year, 1–4 % of people with known gallstones become symptomatic, either presenting with biliary colic or as acute cholecystitis. The distinction between both diagnoses remains challenging. To aid the proper diagnosis, the revised 2013 Tokyo Guidelines (TG 2013) were proposed with a self‐acclaimed diagnostic accuracy of over 90 %. However, this accuracy has not been verified by others so far.

Objective

To determine the accuracy of the TG 2013 guidelines in the diagnosis of acute cholecystitis both in its single components of fever, inflammatory markers and US features and of the combined application of the TG 2013 guidelines as a whole.

Methods

A 5‐year retrospective analysis equal to the TG 2013 validation process of all emergency cholecystectomies for acute cholecystitis or persistent biliary pain with an ultrasound performed during the same admission. Acute cholecystitis at histology was the golden standard.

Results

Inclusion criteria were met by 169 patients with a prevalence of acute cholecystitis of 52.7 %. The individual features of fever, gallbladder wall thickening and probe tenderness were not significant in univariate analysis. In multivariate analysis only, neutrophil count was an independent predictor. The combined application of the TG 2013 guidelines led to a better sensitivity of 83.1 % at the cost a reduced specificity of 37.5 % compared to neutrophil count alone. The accuracy was therefore only 60.3 %, which was well below the TG 2013 report.

Conclusion

The 2013 Tokyo Guidelines were slightly better in predicting acute cholecystitis but over diagnosed two‐thirds of normal gallbladders compared to neutrophil count alone.
All-Trans Retinoic Acid Increases Aquaporin 3 Expression in Human Vaginal Epithelial Cells
Authors: Lee Hyun-Suk , Kim Sun-Ouck , Ahn Kyuyoun , Park Kwangsung
Published: July 2016

Introduction

Water channel aquaporin 3 (AQP3) is an aquaglyceroporin that transports small neutral solutes and water. All-trans retinoic acid (ATRA), a member of the retinoid drug class, acts as a regulator in several biological processes.

Aim

To investigate the effect of ATRA on the expression of AQP3 in human vaginal epithelial cells.

Methods

Human vaginal mucosal epithelial cells (CRL2616) were treated with ATRA 0, 0.01, 0.1, and 1 μmol/L for 24 hours to examine the dose-dependent effects of ATRA and with ATRA 1 μmol/L for 0, 3, 6, 12, and 24 hours.

Main Outcome Measures

The expression of AQP3 and retinoic acid receptor (RAR) was determined by western blot analysis and reverse transcription polymerase chain reaction.

Results

AQP3 was detected in the cell membrane of human vaginal epithelial cells. ATRA increased the protein expression and mRNA levels of AQP3 in a dose-dependent manner (P < .05). ATRA also increased the protein expression of RARα (P < .05). Treatment of CRL2616 cells with an RAR antagonist (Ro 41-5253) significantly decreased AQP3 protein expression (P < .05).

Conclusion

ATRA mediated by RARα increased AQP3 gene and protein expression in human vaginal mucosal epithelial cells. These results imply that AQP3 regulated by ATRA could play an important role in the mechanism of vaginal lubrication.
Early life overnutrition induced by litter size manipulation decreases social play behavior in adolescent male rats
Authors: Carvalho Ana Laura O. , Ferri Bárbara G. , de Sousa Francielly A. Lopes , Vilela Fabiana C. , Giusti‐Paiva Alexandre
Published: July 2016

Several studies have investigated the effects of artificial litter size adjustment on offspring development. Social play behavior is important for neurobehavioral development and is impaired in several developmental psychiatric disorders. This study therefore investigated the effect of litter size on play behavior in adolescent rats. On postnatal day (PND) 2, litters were adjusted to a small litter (SL) size of 3 pups per dam or normal litter (NL) size of 12 pups per dam. Maternal behaviors scored daily during the first week of lactation (PND2‐8) revealed that arched nursing and pup licking behaviors were increased in dams with SLs versus those with NLs. SL offspring exhibited accelerated weight gain and advanced development of physical landmarks and reflexes, possibly due to overnutrition. Social isolation lasting 3.5 h prior to social play behavioral testing produced a higher frequency and duration of pouncing, pinning, sniffing, and grooming in both male and female offspring. However, male SL offspring exhibited a lower frequency of pouncing and pinning when compared with male NL offspring, while no litter size‐dependent differences were observed in social behaviors unrelated to play (sniffing and grooming). These findings identify a possible sexually dimorphic influence of litter size in the development of social behavior. Given that social behaviors such as play behavior are vital for normal cognitive and social development, these findings have important implications for developmental and neuropsychiatric research.
Brands, Friends, & Viral Advertising: A Social Exchange Perspective on the Ad Referral Processes
Authors: Hayes Jameson L. , King Karen Whitehill , Ramirez Artemio
Published: July 2016

Advertisers worldwide are designing advertising with an eye toward viral activity particularly within social networking sites such as Facebook. Yet, little is known about the social processes at play when ads are shared. Taking a consumer-centric approach, this study investigates the social processes central to ads going viral within the Social Web. Conducting a national online experiment, the intertwining roles of brand relationships, interpersonal relationships, and sharing motivations in the social exchange of advertising are explored by testing two proposed referral decision-making processes: referral and referral acceptance. Results suggest that brand relationships and interpersonal relationships impact referral of ads within SNSs, and brand relationships interact with sharing motivations to impact decisions; specifically, brand relationships are conduits for ensuring reciprocal altruism in exchange, but their influence is tempered within stronger interpersonal relationships. Practical and theoretical implications are discussed.
LRG1 mRNA expression in breast cancer associates with PIK3CA genotype and with aromatase inhibitor therapy outcome
Authors: Ramirez-Ardila Diana E. , Ruigrok-Ritstier Kirsten , Helmijr Jean C. , Look Maxime P. , van Laere Steven , Dirix Luc , Berns Els M.J.J. , Jansen Maurice P.H.M.
Published: July 2016

Background

PIK3CA is the most frequent somatic mutated oncogene in estrogen receptor (ER) positive breast cancer. We previously observed an association between PIK3CA genotype and aromatase inhibitors (AI) treatment outcome. This study now evaluates whether expression of mRNAs and miRs are linked to PIK3CA genotype and are independently related to AI therapy response in order to define potential expressed biomarkers for treatment outcome.

Materials and methods

The miR and mRNA expression levels were evaluated for their relationship with the PIK3CA genotype in two breast tumor datasets, i.e. 286 luminal cancers from the TCGA consortium and our set of 84 ER positive primary tumors of metastatic breast cancer patients who received first line AI. BRB Array tools class comparison was performed to define miRs and mRNAs whose expression associate with PIK3CA exon 9 and 20 status. Spearman correlations established miR–mRNA pairs and mRNAs with related expression. Next, a third dataset of 25 breast cancer patients receiving neo‐adjuvant letrozole was evaluated, to compare expression levels of identified miRs and mRNAs in biopsies before and after treatment. Finally, to identify potential biomarkers miR and mRNA levels were related with overall survival (OS) and progression free survival (PFS) after first‐line AI therapy.

Results

Expression of 3 miRs (miR‐449a, miR‐205‐5p, miR‐301a‐3p) and 9 mRNAs (CCNO, FAM81B, LRG1, NEK10, PLCL1, PGR, SERPINA3, SORBS2, VTCN1) was related to the PIK3CA status in both datasets. All except miR‐301a‐3p had an increased expression in tumors with PIK3CA mutations. Validation in a publicly available dataset showed that LRG1, PGR, and SERPINA3 levels were decreased after neo‐adjuvant AI‐treatment. Six miR–mRNA pairs correlated significantly and stepdown analysis of all 12 factors revealed 3 mRNAs (PLCL1, LRG1, FAM81B) related to PFS. Further analyses showed LRG1 and PLCL1 expression to be unrelated with luminal subtype and to associate with OS and with PFS, the latter independent from traditional predictive factors.

Conclusion

We showed in two datasets of ER positive and luminal breast tumors that the expression of 3 miRs and 9 mRNAs associate with the PIK3CA status. Expression of LRG1 is independent of luminal (A or B) subtype, decreased after neo‐adjuvant AI‐treatment, and is proposed as potential biomarker for AI therapy outcome.
Tension and Legality: Towards a Theory of the Executive Branch
Authors: Cohn Margit
Published: July 2016

This article challenges hierarchical and binary thinking in constitutional theory, and offers an alternative basis that draws on multidimensionality. The recognition that constitutionalism is a collection of ingrained tensions between competing forces and conceptual bases is applied in a study of the executive branch, a field that is especially lacking in general theory. The existing research of the executive is almost entirely concerned with specific legal systems and is typically normative; descriptively, references to puzzles and ambiguity offer an inadequate, a-theoretical basis for the understanding of the nature of the executive. Rejecting three alternative models, two of them hierarchical, the third, binary, I reach the internal tension model, which acknowledges the internal irresolvable tension between the executive’s subservience to law and its dominance beyond law, which underlies executive action. The article addresses the ways law can, and does, maintain this internal tension, and ends with some comments on future research directions.
The impact of supervisor–subordinate relationships and a trainee characteristic upon police officer work outcomes
Authors: Brunetto Yvonne , Teo Stephen , Shacklock Kate , Farr-Wharton Rod , Shriberg Art
Published: July 2016

This study used two theoretical lenses (positive organizational behaviour and social exchange theory) to examine the influence of an individual attribute – psychological capital (PsyCap), and an organizational factor – leader–member exchange, upon police officers’ perceptions of learning options (teamwork and training) and affective commitment. A cross-sectional design using a survey-based, self-report strategy was used to collect data from 588 frontline police officers in the United States. The findings indicate that leader–member exchange explained almost a fifth of PsyCap and together leader–member exchange and PsyCap accounted for almost a third of police officers’ satisfaction with training. Further, leader–member exchange, PsyCap, training and teamwork collectively explain almost half of affective commitment. One implication of the findings is that if senior management want police officers to be more committed, they have to improve officers’ relationships with their supervisors, upskill them (especially their supervisors) in PsyCap, and improve teamwork opportunities and processes.
Self-employment: Deviation or the norm?
Authors: Bridge Simon
Published: July 2016

In many countries self-employment has increased recently. But, despite evidence that many people enter self-employment willingly out of choice, there appears to be an instinctive aversion to it, possibly based on an assumption that employment is more desirable and beneficial and is, and should be, the norm. Often using a UK viewpoint, this paper examines the history of work and suggests that, in historical terms, employment is the exception not the norm. The age of the job, it is claimed, lasted only from 1840 to 1980, but its influence continues and many government regulations and union practices are still based on the era of the big business, big labour and big government triumvirate. Therefore, if the future is not to be constrained by laws and practices designed for the past, it is important to identify the perceptions and assumptions which prevail about employment and to highlight those which are incorrect.
Intracolony variation in colony morphology in reassembled fossil ramose stenolaemate bryozoans from the Upper Ordovician (Katian) of the Cincinnati Arch region, USA
Authors: Key Marcus M. , Wyse Jackson Patrick N. , Felton Stephen H.
Published: July 2016

Clusters of associated colony fragments discovered weathering out of bedding planes in the Upper Ordovician of the Cincinnati, Ohio, region provide a rare opportunity to quantify intracolony variation in ramose stenolaemate bryozoans. Sixteen colonies were reassembled as completely as possible from 198 fragments, and the following colony-level characters were measured: colony dimensions, branch link length and diameter, and branch order. Results indicate that branch link length and diameter systematically decrease as colonies grow via branch bifurcation. Branching ratio (i.e., the number of distal first-order branches divided by the number of immediately proximal second-order branches) appears to be more genetically than environmentally controlled and to be consistent among orders of stenolaemates and perhaps across the phylum. Colonies with endozones mined out by endoskeletozoans result in broken branches as opposed to pristine growing tips. This varies stratigraphically, perhaps in response to the distribution of the boring animals. The rarity of borers and the systematic proximal increase in branch diameter in these colonies suggest the zooids in the proximal portions of the colonies were alive at the time of colony death. If the time and effort can be invested in reassembling colonies, these morphometric data can then be applied to taxonomic, phylogenetic, and paleoenvironmental studies.
Bag of Tricks: A Set of Techniques and other Resources to Help 14C Laboratory Setup, Sample Processing, and Beyond
Authors: Santos Guaciara M , Xu Xiaomei
Published: July 2016

Over the last few decades, radiocarbon laboratories have used different procedures for measuring a broad range of carbonaceous materials. To produce reliable results, the processes employed for sample processing, graphite target production, and spectrometer measurement must be rigorous, well tested, and reproducible. Most of the procedures have been developed, improved, and published as part of the laboratories’ quality control and research programs, and can be frequently found in the literature. Nevertheless, there are suites of laboratory techniques (or “small useful skills”), products, and other resources that either have never been described in publications, or have been somewhat hidden in much larger scientific articles and reports. We feel that with the rapid rise of newer laboratories and facilities, a set of resourceful suggestions might come in handy. Here we gathered these skill sets that can be used in all aspects of 14C sample processing, with the intention to simplify and expedite procedures, from glass-tube making to graphitization and measurements. We also included some miscellaneous items to help in laboratory setup.
An array of sixth abdominal tergite types of paguroid anomurans (Crustacea) from the mid-Cretaceous of Navarra, northern Spain
Authors: Fraaije R.H.B. , Artal P. , van Bakel B.W.M. , Jagt J.W.M. , Klompmaker A.A.
Published: July 2016

In recent years, a range of operculate sixth abdominal tergite types of pylochelid and parapylochelid hermit crabs (Anomura, Paguroidea) have been recorded from Upper Jurassic (Oxfordian and Kimmeridgian) strata in southern Poland and southern Germany. Here we add two new genera (Parapylochelitergites, Paguritergites) and four new late Early Cretaceous species (Parapylochelitergites pustulosus, Pylochelitergites alatus, Pylochelitergites rugosusandPaguritergites yvonnecooleae) from Navarra, northern Spain. In the reefal limestones at Koskobilo quarry near Alsasua, of late Albian age, the number of sixth abdominal paguroid tergite taxa approximates that of paguroid carapace types. Thus, linking fossil paguroid carapaces to tergites can now be attempted. Assemblages of symmetrical hermit crabs (parapylochelids and pylochelids) in reefal settings appear to have changed drastically from the late Albian onwards, with asymmetrical forms (Diogenidae, Paguridae) becoming predominant.
Aspects of clavate borings in the type Maastrichtian (Upper Cretaceous) of the Netherlands and Belgium
Authors: Donovan S.K. , Jagt J.W.M.
Published: July 2016

We describe a collection of borings in carbonate and xylic substrates (Gastrochaenolites ispp., Teredolites longissimus Kelly & Bromley), some of them containing their producers, from the Maastricht and Houthem formations (late Maastrichtian and early Danian) in the type area of the Maastrichtian Stage, but mainly from the ENCI-HeidelbergCement Group quarry, St. Pietersberg (southern Limburg, the Netherlands). Included are specimens of Gastrochaenolites dijugus Kelly & Bromley, showing different modes of formation of the figure-of-eight aperture, either as part of the lining, incorporating the substrate or both. Gastrochaenolites lapidicus Kelly & Bromley was produced by the gastrochaenid bivalve Gastrochaena, whereas G. orbicularis Kelly & Bromley is the trace of Jouannetia supracretacea (De Ryckholt). Bioglyph-like infills of G. orbicularis and G. torpedo Kelly & Bromley rather represent external moulds of the producing bivalves; they are termed pseudobioglyphs herein. Teredolites longissimus is preserved as clusters of in situ, parallel to sub-parallel tubes, although the woody substrate has decayed, and disarticulated fragments of calcareous tubes have been released from rotten wood. The latter include some specimens filled by flint and show good three-dimensional preservation. Some notes on the taxonomy of the producing bivalve taxa are added.
The first North American record of Carinodens belgicus (Squamata, Mosasauridae) and correlation with the youngest in situ examples from the Maastrichtian type area: palaeoecological implications
Authors: Mulder E.W.A. , Formanoy P. , Gallagher W.B. , Jagt J.W.M. , Schulp A.S.
Published: July 2016

Four recently collected tooth crowns of the rare latest Cretaceous (late Maastrichtian) durophagous mosasaur Carinodens belgicus are discussed; the first record from the Atlantic coast of North America (Maryland), and three additional in situ examples from the Maastrichtian type area in the southeast Netherlands and northeast Belgium. Also presented are an updated overview of the material recorded to date, and a discussion of the palaeobiogeographical and palaeoenvironmental distribution of the genus. Towards the end of the Cretaceous, Carinodens appears to have been successful in exploiting the margins of both the proto-Atlantic Ocean and the Tethyan Realm.
Bone damage in Allopleuron hofmanni (Cheloniidae, Late Cretaceous)
Authors: Janssen R. , van Baal R.R. , Schulp A.S.
Published: July 2016

We describe pathologies and post-mortem damage observed in specimens of the late Maastrichtian marine cheloniid turtle Allopleuron hofmanni. Shallow circular lesions on carapace bones are common and possibly illustrate barnacle attachment/embedment. Deep, pit-like marks are confined to the neural rim and the inner surface of peripheral elements; these may have been caused either by barnacle attachment or disease. A number of linear marks found on outer carapace surfaces are identified as tooth marks of scavengers, others as possible domichnia of boring bivalves. A fragmentary scapula and prescapular process displays radular traces of molluscs (gastropods and/or polyplacophorans; ichnogenus Radulichnus). These diverse types of bone damage suggest both live and dead marine turtles to have been commonly utilised by predators, scavengers and encrusters in the type Maastrichtian marine ecosystem.
On diving and diet: resource partitioning in type-Maastrichtian mosasaurs
Authors: Schulp A.S. , Vonhof H.B. , van der Lubbe J.H.J.L. , Janssen R. , van Baal R.R.
Published: July 2016

The carbon isotope composition of tooth enamel from all five mosasaur taxa known to date from the type Maastrichtian (southeast Netherlands, northeast Belgium) has been analysed. Differences in enamel δ13C values between taxa suggest resource partitioning. Body size and δ13C value correlate surprisingly well, with larger taxa having δ13C values more depleted in the heavier 13C isotope.
Tracking consolidant penetration into fossil bone using neutron radiography
Authors: Schulp A.S. , Schouten R. , Metten L. , van de Sande A. , Bontenbal A.
Published: July 2016

In the conservation of fragile fossil bone material, impregnation by solvent-borne consolidant is often required. Understanding the mode of penetration of consolidants into fossil bone is of crucial importance. It is governed by a variety of factors; neutron imaging is a powerful tool to monitor and visualise this penetration (non-destructively). The consolidation of a vertebrate fossil from the Maastrichtian of the southeast Netherlands was imaged at the High Flux Reactor facility at Petten, the Netherlands. The analysis shows current conservation practice to result in a sufficiently deep and isotropic penetration.
A bifacial tool of the Neanderthals from Ameland, the Netherlands
Authors: Stapert D. , Johansen L. , Niekus M.J.L.Th.
Published: July 2016

A bifacially worked flint tool has recently been found on the North Sea beach of Ameland, one of the Wadden Islands in the northern Netherlands. It probably dates from the Middle Palaeolithic because its surface modifications include windgloss which in this area originated especially during the Weichselian Late Pleniglacial. The tool was probably first worked by a skilled knapper and subsequently, after a break occurred, by an apprentice. It is suggested that the tool was transported to Ameland from the North Sea bottom in the course of sand replenishment activities. Other artefacts from the Wadden Islands allegedly left by Neanderthals are also briefly discussed.
Two rare mosasaurs from the Maastrichtian of Angola and the Netherlands
Authors: Schulp A.S. , Polcyn M.J. , Mateus O. , Jacobs L.L.
Published: July 2016

We report here the addition of two rare mosasaur taxa to the Maastrichtian marine amniote fauna of Angola, both of which are also found in northern Europe. The new specimens include a dentary fragment referable to the large carnivorePrognathodoncf.saturatorand an isolated tooth of the small durophageCarinodens belgicus. Both were recovered from Maastrichtian outcrops in southern Angola in 2011. Additionally, a complete posterior mandibular unit of a large mosasaur from the type Maastrichtian of the Netherlands, collected some time prior to 1879 and previously identified as ‘Mosasaurus giganteus’, is described and reassigned here toPrognathodon saturator; historical issues surrounding the taxonomic attribution of this specimen are clarified. The new material extends the known geographic distribution ofPrognathodon saturatorandCarinodens belgicus.
The Roman Limes in the Netherlands: how a delta landscape determined the location of the military structures
Authors: van Dinter M.
Published: July 2016

From the 40s A.D. onwards a dense military system was established in the Lower Rhine delta in the Netherlands. Long since, it is questioned why this system was established in a wetland area and even turned into the northwest frontier of the Roman Empire, theLimes. A new detailed palaeogeographical map, based on a digital elevation model (LIDAR), soil maps and excavation results, was constructed. This reconstruction provides insight and understanding of the interactions between the natural environment in this part of the delta on the one hand and the establishment of this part of theLimesalong the Old Rhine between Utrecht and Katwijk on the other. This study shows that the distinctive landscape of the western Rhine-Meuse delta, with an exceptionally large number of tributaries, determined the spatial pattern of the military structures. All forts (castella) were erected on the southern natural levees of the river Rhine, directly alongside the river, regardless of height and composition of the subsoil and alongside or opposite routes that provided natural access to the river. We conclude that their aim was to guard all waterways that gave access to the river Rhine from the Germanic residential areas further north and from/to the Meuse tributary further south in the delta. In addition, a system of small military structures, mostly watchtowers, was erected between the forts to watch over the river Rhine and its river traffic. Furthermore, at least two canals were established to create shorter and safely navigable transport routes to the river Meuse. At first, this integrated system of castella and watchtowers probably aimed to protect against Germanic invasions and to create a safe corridor for transport and built up of army supplies for the British invasion in 43 A.D. Only later on, probably by the end of the first century, this corridor turned into a frontier zone.
Probable remains of jellyfish (Cnidaria, Scyphozoa) from the lower Middle Triassic (Anisian) of Winterswijk, eastern Netherlands
Authors: Oosterink H.W. , Winkelhorst H.
Published: July 2016

During recent years, regular round structures have been collected from the top of Bed 12 of the Vossenveld Formation (Lower Muschelkalk, lower Middle Triassic, Anisian) in the Winterswijk area, eastern Netherlands. These are here illustrated and described as probable remains of jellyfish.
Reconstruction of burial history, temperature, source rock maturity and hydrocarbon generation in the northwestern Dutch offshore
Authors: Fattah R. Abdul , Verweij J.M. , Witmans N. , ten Veen J.H.
Published: July 2016

3D basin modelling is used to investigate the history of maturation and hydrocarbon generation on the main platforms in the northwestern part of the offshore area of the Netherlands. The study area covers the Cleaverbank and Elbow Spit Platforms. Recently compiled maps and data are used to build the input geological model. An updated and refined palaeo water depth curve and newly refined sediment water interface temperatures (SWIT) are used in the simulation. Basal heat flow is calculated using tectonic models. Two main source rock intervals are defined in the model, Westphalian coal seams and pre-Westphalian shales, which include Namurian and Dinantian successions. The modelling shows that the pre-Westphalian source rocks entered the hydrocarbon generation window in the Late Carboniferous. In the southern and central parts of the study area, the Namurian started producing gas in the Permian. In the north, the Dinantian source rocks appear to be immature. Lower Westphalian sediments started generating gas during the Upper Triassic. Gas generation from Westphalian coal seams increased during the Paleogene and continues in present-day. This late generation of gas from Westphalian coal seams is a likely source for gas accumulations in the area.

Westphalian coals might have produced early nitrogen prior to or during the main gas generation occurrence in the Paleogene. Namurian shales may be a source of late nitrogen after reaching maximum gas generating phase in the Triassic. Temperatures reached during the Mid Jurassic were sufficiently high to allow the release of non-organic nitrogen from Namurian shales.
Late Cenozoic shelf delta development and Mass Transport Deposits in the Dutch offshore area – results of 3D seismic interpretation
Authors: Benvenuti A. , Kombrink H. , ten Veen J.H. , Munsterman D.K. , Bardi F. , Benvenuti M.
Published: July 2016

In this study, seismic stratigraphic criteria have been used to characterise the evolution of the Southern North Sea (SNS) shelf-delta system that progressively filled the Southern North Sea basin during Plio-Pleistocene times. Based on the prograding and down-stepping architecture of the shelf-delta sequence it is inferred that deposition occurred during a time of high sediment supply and overall sea-level lowering. During this time the delta slopes failed several times, creating at least 30 internally coherent Mass Transport Deposits (MTDs) mainly grouped in common areas, affecting the same clinoform set and partially sharing the basal shear surface (groups of MTDs). The most important features of the studied MTDs are 1) the dominance of brittle deformation; 2) the small amount of material removal from the headwall domain (lack of completely depleted areas above the basal shear surface); and 3) the lack of an emergent toe domain above the un-failed sediment located basinward, although proper confining geometries for the MTD are not detected. Therefore, the studied MTDs can neither be classified as frontally confined nor as frontally emergent but they are a new intermediate type of submarine landslides which has not been described before. These characteristics suggest that the mass movement ceased relatively soon after initiation of failure. Incisions on top of the MTDs suggest the presence of erosive flows. These flows were probably generated due to a concentration of the drainage in the negative morphology the failure event left behind in the upper sector of the slope. The stronger progradational character of the reflections on top of MTDs confirms a concentration of drainage after the erosional phase too.

The interplay between high sediment supply and constant or even decreasing accommodation space (caused by constant or decreasing sea-level) is supposed to be the main precondition for slope instability for most of the MTDs in this study area. Slope failures themselves can also be considered a preconditioning factor by the creation of local very high sedimentation rates (see groups of MTDs). Salt-induced seismicity and storm waves' effect superimposed on high frequency sea level fall are considered the most important triggering factors.
Geothermal aquifer performance assessment for direct heat production – Methodology and application to Rotliegend aquifers
Authors: J.-D. van Wees  , Kronimus A. , van Putten M. , Pluymaekers M.P.D. , Mijnlieff H. , van Hooff P. , Obdam A. , Kramers L.
Published: July 2016

In this paper we present a probabilistic fast model for performance assessment of geothermal doublets for direct heat applications. It is a simple yet versatile and multipurpose tool. It can be well applied in better understanding the sensitivity of performance to key subsurface parameters and depth trends therein, and for assessing the probability of success for geothermal projects under technical and financial constraints.

The underlying algorithms deliver a sensible accuracy given the uncertainties associated with geothermal projects at exploration state. A public release of the software, available under the name of DoubletCalc, is easy to handle and requires a limited set of input parameters. Thanks to an open source code, DoubletCalc can be implemented in other software applications and extended as it has been implemented for the integration into the national geothermal information system in the Netherlands (ThermoGIS, 2011).

Apart from its application for site assessments, the tool can be integrated into automated workflows processing faster representations of key aquifer properties and capable to produce indicative maps for predicted doublet power, economic feasibility and prediction of cumulative amount of heat that can be recovered. These capabilities are specifically important for decision support for policymakers while assessing the effects of particular insurance schemes and funding mechanisms.

DoubletCalc cannot and is not intended to substitute geologic exploration approaches. As exploration measures, such as seismic surveys are cost intensive, DoubletCalc can be used to focus geothermal exploration on areas and sites where an enhanced probability of success can be expected.
Turning the tide: experimental creation of tidal channel networks and ebb deltas
Authors: Kleinhans M.G. , van der Vegt M. , van Scheltinga R. Terwisscha , Baar A.W. , Markies H.
Published: July 2016

Tidal channel networks, estuaries and ebb deltas are usually formed over a period longer than observations cover. Much is known about their characteristics and formation from linear stability analyses, numerical modelling and field observations. However, experiments are rare whilst these can provide data-rich descriptions of morphological evolution in fully controlled boundary and initial conditions. Our objective is to ascertain whether tidal basins can be formed in experiments, what the possible scale effects are, and whether morphological equilibrium of such systems exists.

We experimentally created tidal basins with simple channel networks and ebb deltas in a 1.2 by 1.2 m square basin with either a fixed or self-formed tidal inlet and initially flat sediment bed in the tidal basin raised above the bed of the sea. Rather than create tides by varying water level, we tilted the entire basin over the diagonal. The advantage of this novel method is that the bed surface slopes in downstream direction both during flood and ebb phases, resulting in significant transport and morphological change in the flood phase as well as the ebb phase. This overcomes the major problem of earlier experiments which were entirely ebb-dominated, and reduces the experiment time by an order of magnitude.

Ebb deltas formed in sand were entirely bedload dominated whereas the lightweight plastic sediment was intermittently suspended. Channels bifurcated during channel deepening and backward erosion to form a network of up to four orders. For initially dry tidal plains, the tidal prism increased as more sediment eroded from basin to ebb delta, so that evolution accelerated initially. The rate of change, the size of the channels and the final length of channels and delta were very sensitive to the tidal amplitude, tidal period and initial water depth in the basin. Most experiments with sand terminated with all sediment below the threshold for motion, whilst lightweight sediment remained mobile in the inlet region and firstorder channels, suggesting that sustained morphodynamics are feasible in experiments. We discuss how this novel experimental setup can be extended to produce tidal deltas, estuaries and other tidal systems and study their dynamics as a function of their forcing.
Morphodynamics of a storm-dominated, shallow tidal inlet: the Slufter, the Netherlands
Authors: van der Vegt M. , Hoekstra P.
Published: July 2016

In this article we study the morphodynamics of the Slufter on the short-term (months) and long-term (years to decades). The Slufter is a small, shallow tidal inlet located on the island of Texel, the Netherlands. A narrow (tens of meters) channel connects the North Sea with a dune valley of 400 ha. This narrow channel is located in between a 400-700 m wide opening in the dunes. Approximately 80% of the basin of the Slufter is located above mean high water level and is flooded only during storms, when a threshold water level is exceeded.

Analysis of historical aerial photographs revealed that the inlet channel migrates about 100 m per year. In the 1970's it migrated to the south, while since 1980 it is migrating to the north. When the channel reached the dunes at the north side of the dune breach the channel was relocated to the south by man. The channel inside the backbarrier basin was less dynamic. It shows a gradual growth and southward migration of a meander on a decadal time scale.

The short-term dynamics of the Slufter were studied during a field campaign in 2008. The campaign aimed at identifying the dominant hydrodynamic processes and morphological change during fair weather conditions and during storm events. During fair weather flow velocities in the main inlet channel were 0.5-0.8 m/s at water depths of 0-1.5 m, slightly ebb-dominant and associated morphological change was small. When water levels were above critical levels during a storm period the hydrodynamics in the main channel drastically changed. The flow in the main channel was highly ebb dominant. Long ebb periods with typical flow velocities of 2 m/s were alternated by much shorter flood periods with typical velocities of 0.5-1 m/s. This resulted in a net outflow of water via the main channel, while we measured a net inflow of water at the beach plain. During the storm period in 2008 we measured a 10 m migration of the channel to the north.

We conclude that the Slufter is a storm-dominated tidal inlet system.
The use of fluvial archives in reconstructing landscape evolution: the value of sedimentary and morphostratigraphical evidence
Authors: Bridgland D.R. , Westaway R.
Published: July 2016

Evidence-based interpretations of fluvial evolution, and especially of river-terrace formation, have advanced significantly in recent decades, with a notable contribution made by activities of the Fluvial Archives Group. Well-dated river-terrace sequences provide frameworks for the understanding of landscape evolution, since they record valley-floor levels that were higher in the past, attributable, from their patterns of occurrence, to regional uplift. The role of climate fluctuation during the Quaternary is also paramount, since this has been an important driver of the varied fluvial activity that has given rise to the staircases of terraces that characterise the temperate latitudes. This approach is contrasted with a more theoretical methodology for using rivers as recorders of landscape evolution, again with an emphasis on uplift, based on the concept of the formation of knickpoints at particular base levels and their migration upstream. Although different timescales can be explored by the two methods, the concept of headward-migrating knickpoints implies a mechanism for incision that is difficult to reconcile with the formation of the broadly parallel river terraces that are observed in many systems. Knickpoints can frequently be observed to coincide with gorge reaches, where river valleys are constricted as a result of resistant bedrock and/or the effects of localised active crustal deformation. This raises the possibility that knickpoints have generally formed in response to factors of local geology rather than migrating from downstream.
Late-Pleistocene paleohydrography, eolian activity and frozen ground, New Jersey Pine Barrens, eastern USA
Authors: French H. , Demitroff M.
Published: July 2016

The Late Pleistocene surface paleohydrography of the New Jersey Pine Barrens consisted of a series of broad braided alluvial surfaces with meandering paleochannels. This drainage is best explained in terms of impermeable (i.e. frozen) substrate, high sediment load, variable or decreasing discharge, and eolian sedimentary dynamics. Evidence for eolian activity is provided by wind-abraded sand grains, coversand, dunes, ventifacts, deflation hollows and wind-polished boulders. In several places stream avulsion occurred due to channel infilling by locally-derived wind-blown sediment. The braided and meandering river systems that characterise the tundra and polar semi-desert lowlands of the Western Canadian Arctic are described as modern analogs.
The oldest beaver from the Netherlands
Authors: Wessels W. , Frieling J. , Fraaije R.
Published: July 2016

A lower molar of Castor fiber from the sandpit of Langenboom (the Netherlands) represents, so far, the oldest occurrence of a beaver in the North Sea Basin. Its presence in the marine sand deposit of the Langenboom Formation indicates that Castor fiber inhabited areas in or near the river systems of Rhine and Meuse in the Early Pliocene.
Dutch natural gas strategy: historic perspective and challenges ahead
Authors: Weijermars R. , Luthi S.M.
Published: July 2016

We highlight a watershed in the natural gas legacy of the Netherlands: after 50 years of successful gas development, production output of conventional fields will decline from 2010 onwards. The projected decline in Dutch gas output will lead to a loss of future income for the State. In the past, E&P companies were prepared to compete for access to Dutch assets and lead in research as well as in the exploration for the development ofconventionalgas resources. Today, this cannot be assumed for the development of unconventional resources. It is not clear from our current state of knowledge whether the riskier unconventional gas resources in the Netherlands will be attractive for E&P companies. For example, are the financial risks for maturing potential unconventional resources into economic proved reserves acceptable to them? The US boom in unconventional gas production was preceded by government sponsored research programmes that stimulated the development of unconventional gas production technology. Decline in domestic gas production in the Netherlands therefore prompts for a dedicated upstream gas research programme. This will help to unlock future value from stranded conventional gas and unexplored unconventional gas resources. If such new gas resources can indeed be developed with the aid of research, undue loss of state income can be mitigated, which makes such a programme a compelling business case.
Fluvial architecture of Belgian river systems in contrasting environments: implications for reconstructing the sedimentation history
Authors: Notebaert B. , Houbrechts G. , Verstraeten G. , Broothaerts N. , Haeckx J. , Reynders M. , Govers G. , Petit F. , Poesen J.
Published: July 2016

Accurate dating is necessary to get insight in the temporal variations in sediment deposition in floodplains. The interpretation of such dates is however dependent on the fluvial architecture of the floodplain. In this study we discuss the fluvial architecture of three contrasting Belgian catchments (Dijle, Geul and Amblève catchment) and how this influences the dating possibilities of net floodplain sediment storage. Although vertical aggradation occurred in all three floodplains during the last part of the Holocene, they differ in the importance of lateral accretion and vertical aggradation during the entire Holocene. Holocene floodplain aggradation is the dominant process in the Dijle catchment. Lateral reworking of the floodplain sediments by river meandering was limited to a part of the floodplain, resulting in stacked point bar deposits. The fluvial architecture allows identifying vertical aggradation without erosional hiatuses. Results show that trends in vertical floodplain aggradation in the Dijle catchment are mainly related to land use changes. In the other two catchments, lateral reworking was the dominant process, and channel lag and point bar deposits occur over the entire floodplain width. Here, tracers were used to date the sediment dynamics: lead from metal mining in the Geul and iron slag from ironworks in the Amblève catchment. These methods allow the identification of two or three discrete periods, but their spatial extent and variations is identified in a continuous way. The fluvial architecture and the limitation in dating with tracers hampered the identification of dominant environmental changes for sediment dynamics in both catchments. Dating methods which provide only discrete point information, like radiocarbon or OSL dating, are best suited for fluvial systems which contain continuous aggradation profiles. Spatially more continuous dating methods, e.g. through the use of tracers, allow to reconstruct past surfaces and allow to reconstruct reworked parts of the floodplain. As such they allow a better reconstruction of past sedimentation rates in systems with important lateral reworking.