Firm Ground Research Articles

Exploring the aftermath of the Cambrian explosion: The evolutionary significance of marginal- to shallow-marine ichnofaunas of Jordan

The middle Cambrian Hanneh Member of the Burj Formation and the middle to upper Cambrian Umm Ishrin Formation of the Dead Sea area, Jordan, contain well-preserved and abundant ichnofaunas. Trace fossils are present in a wide variety of depositional environments, from tide-dominated shelf to prodelta, delta front and interdistributary-bay tidal flats. Twelve trace fossil assemblages have been identified within a number of sequence-stratigraphic settings, namely early transgressive subtidal dune and bar complex, late transgressive isolated dune patches and dune-field abandonment, highstand deltaic progradation, and forced-regressive deltaic progradation. These ichnofaunas provide information that helps us to understand the nature of Cambrian ecosystems in the aftermath of the Cambrian radiation. The Jordan ichnofaunas display evidence of firm ground conditions at or near the sea bottom. These include (1) well-preserved scratch marks in most Cruziana and Rusophycus ichnospecies, (2) adhering Gyrolithes polonicus burrows, and (3) unlined passively filled Diplocraterion isp. penetrating into underlying mudstone. Whereas the Diplocraterion isp. occurrences are a classic example of the Glossifungites ichnofacies linked to erosional exhumation, the firmground G. polonicus is associated to a maximum flooding surface with no erosion involved. The trace fossil suites dominated by trilobite structures are firmground examples of the Cruziana ichnofacies, raising issues with respect to the substrate affinities of this ichnofacies, which is typically considered indicative of softgrounds. Our study underscores evolutionary controls on this ichnofacies, suggesting that lower Paleozoic occurrences, which are dominated by trilobite trails and trackways, reflect firm substrates and younger ones represent the typical softground examples. The occurrence of abundant bilobate trace fossils, scratch marks and trackways in interdistributary-bay tidal flats within a braidplain delta complex in the Umm Ishrin Formation provides evidence that arthropods were able to foray into marginal-marine brackish-water settings during the Cambrian. Analysis of the tiering structure indicates relatively simple communities and limited use of the infaunal ecospace. Low-energy fully marine and marginal-marine ichnofabrics are dominated by shallow-tier deposit- and detritus-feeding trace fossils. Deep-tier structures of detritus feeders are present in ichnofabrics from fully marine low-energy settings, whereas deep-tier trace fossils of suspension feeders are dominant in high-energy subtidal zones.

A distributed mass structural system for soil-structure-interaction and base isolation studies

A base isolation system placed within a structure for seismic protection will perform differently in the presence of soil-structure-interaction phenomena, as compared to the case where the structure is founded on competent soil and/or rock. This is so for two basic reasons: (a) there is filtering affecting the input ground motion signal at the base of the structure, and (b) the overall mechanical characteristics of the combined soil-structure system have changed as compared to the original structure resting on firm ground. Thus, a base isolation design has to account for soil-structure-interaction in order to have the system fine-tuned to the particular geological conditions and seismicity of the construction site in question. In this work, we introduce a distributed mass representation of the superstructure that has four possible dynamic response modes, namely flexure, shearing, torsion and axial vibrations. The foundation is treated as a rigid block, and the soil is represented by the equivalent spring-damper-virtual mass system, whereby these mechanical parameters may be frequency dependent. Typical base isolation systems used nowadays are lead rubber bearing designs whose mechanical behavior comprises a spring element, a damper and a hysteretic component. In terms of analysis, a substructuring methodology is employed that is cast in the frequency domain, with conditions of equilibrium and compatibility enforced at the common structure-foundation-soil boundaries. This approach is both efficient and adequate for investigating soil-structure-interaction effects, but cannot handle the hysteretic behavior of the base isolator, which is better captured by using time-stepping algorithms. In closing, some comments are made regarding possible ways for incorporating the base isolator in the present soil-structural system analysis, along with some preliminary results.

Strong Ground Motion Attributes of the 2010 Mw8.8 Maule, Chile, Earthquake

The Mw8.8 Maule, Chile, earthquake produced 31 usable strong motion recordings from currently accessible arrays over a rupture distance range of 30 to 700 km. Site conditions range from firm rock to soft soil but are most often competent soil (NEHRP Category C or C/D). Most of the data were recorded on analogue instruments, which was digitized and processed with low- and high-cut filters designed to maximize the usable frequency range of the signals. The stations closest to the fault plane do not exhibit evidence of ground motion polarization from rupture directivity. Response spectra of nearby recordings on firm ground and soft soil indicate pronounced site effects, including several cases of resonance at site periods. A prior GMPE for interface subduction events captures well the distance scaling and dispersion of the data, but under-predicts the overall ground motion level, perhaps due to too-weak magnitude scaling.

MOLECULAR BIOLOGY AT THE QUANTUM LEVEL: CAN MODERN DENSITY FUNCTIONAL THEORY FORGE THE PATH?

Recent years have seen vast improvements in the ability of rigorous quantum-mechanical methods to treat systems of interest to molecular biology. In this review article, we survey common computational methods used to study such large, weakly bound systems, starting from classical simulations and reaching to quantum chemistry and density functional theory. We sketch their underlying frameworks and investigate their strengths and weaknesses when applied to potentially large biomolecules. In particular, density functional theory — a framework that can treat thousands of atoms on firm theoretical ground — can now accurately describe systems dominated by weak van der Waals interactions. This newfound ability has rekindled interest in using this tried-and-true approach to investigate biological systems of real importance. In this review, we focus on some new methods within the density functional theory that allow for accurate inclusion of the weak interactions that dominate binding in biological macromolecules. Recent work utilizing these methods to study biologically relevant systems will be highlighted, and a vision for the future of density functional theory within molecular biology will be discussed.

Graphene nanoribbons subject to gentle bends

Since graphene nanoribbons are thin and flimsy, they need support. Support gives firm ground for applications, and adhesion holds ribbons flat, although not necessarily straight: ribbons with high aspect ratio are prone to bend. The effects of bending on ribbons' electronic properties, however, are unknown. Therefore, this article examines the electromechanics of planar and gently bent graphene nanoribbons. Simulations with density-functional tight-binding and revised periodic boundary conditions show that gentle bends in armchair ribbons can cause significant widening or narrowing of energy gaps. Moreover, in zigzag ribbons sizeable energy gaps can be opened due to axial symmetry breaking, even without magnetism. These results infer that, in the electronic measurements of supported ribbons, such bends must be heeded.

Plasma transfusion for patients with severe hemorrhage: what is the evidence?

The following review will detail the current knowledge in massive hemorrhage with regard to the pathophysiology of the coagulation disturbance, the role of plasma, the role of alternatives to plasma, and the clinical value of having a massive transfusion protocol. The coagulation disturbance in trauma patients is more than just the result of consumption of clotting factors at sites of injury and dilution from the infusion of intravenous fluids and red blood cells (RBCs). Even before substantial amounts of fluid resuscitation and RBC transfusion, one-quarter of trauma patients already have abnormal coagulation variables. There is an apparent role for the activation of protein C, hypofibrinogenemia, and fibrin(gen)olysis in the coagulation disturbance after trauma and massive hemorrhage. None of these three disturbances would be completely mitigated by the use of plasma alone, suggesting that there may be an opportunity to improve care of these patients with alternative strategies, such as fibrinogen concentrates and antifibrinolytics. Despite numerous retrospective cohort studies evaluating 1:1 plasma to RBC formula-driven resuscitation, the overall clinical value of this approach is unclear. Studies have even raised concerns regarding a potential increase in morbidity associated with this approach, particularly for patients overtriaged to 1:1 where a massive transfusion is unlikely. We also do not have sufficient evidence to recommend either goal-directed therapy with thromboelastography or early use of fibrinogen replacement, with either cryoprecipitate or fibrinogen concentrates. We have high-quality data that argue against the role for recombinant Factor VIIa that should prompt removal of this strategy from existing protocols. In contrast, we have high-level evidence that all bleeding trauma patients should receive tranexamic acid as soon as possible after injury. This therapy must be included in hemorrhage protocols. If we are to improve the care of massively bleeding patients on a firm scientific ground, we will need large-scale randomized trials to delineate the role of coagulation replacement and the utility of laboratory monitoring. But even until these trials are completed, it is clear that a massive transfusion protocol is needed in all hospitals that manage bleeding patients, to ensure a prompt and coordinated response to hemorrhage.

The Trouble with ‘Tacit Knowledge’

The development and maintenance of organized cooperative work practices require, as an integral feature, what can loosely be termed `didactic practices' or `mutual learning' (giving and receiving instruction, advice, direction, guidance, recommendation, etc.). However, such didactic practices have not been investigated systematically in CSCW. Michael Polanyi's notion of `tacit knowledge' vs. `explicit knowledge', which plays a key role in the area of Knowledge Management, would seem to offer an obvious framework for investigating didactic practices in CSCW. But as argued in this article, the notion of `tacit knowledge' is a conceptual muddle that mystifies the very concept of practical knowledge. The article examines the historical context in which the notion of `tacit knowledge' was devised, the purpose for which it was formulated, its original articulation, and the perplexing ways in which it has been appropriated in Knowledge Management. In an attempt to gain firm ground for our research, the article towards the end offers a general analysis of the concept of `knowledge', informed by the work of Gilbert Ryle and Alan White. Overall, the article argues that a framework based on the notion of `tacit knowledge', or on similar conceptions devoted to categorizations of kinds of knowledge, impairs the for CSCW essential focus on actual work practices: instead of focusing on forms of symbolism, what is required is to focus on uncovering the logics of actual didactic practices in cooperative work.

Risk factors for superficial digital flexor tendinopathy in Thoroughbred racehorses in hurdle starts in the UK (2001–2009)

Superficial digital flexor (SDF) tendinopathy is a common injury in Thoroughbred horses racing over hurdles. Identification of risk factors may allow the introduction of measures to minimise the incidence of this injury. To identify risk factors for SDF tendinopathy in Thoroughbred horses in hurdle races in the UK. Potential risk factors for SDF tendinopathy were studied between 1 January 2001 and 31 December 2009 using a retrospective cohort study design with 1031 case starts and 168,637 control starts. Potential risk factors were screened using univariable logistic regression prior to multivariable model building. IN the final multivariable model, 20 statistically significant risk factors were identified. Variables found to be associated with increased odds of SDF tendinopathy included: firmer going; increased horse age at first race; having had a previous SDFT injury; and racing in the summer compared to other seasons. Variables found to be associated with decreased odds included: being trained by a more successful trainer; and having raced more frequently in the preceding 9-12 months. This study identified multiple risk factors associated with SDF tendinopathy, some of which are difficult to explain with the current data source. Factors resulting in increased cumulative horse and tendon fatigue (increased years in racing; carrying increased weight; and racing over longer distances), firm ground, and the presence of previous tendon injury should be considered when attempting to reduce the likelihood of sustaining SDF tendinopathy. The results will facilitate the development of strategies to improve the overall safety of horses in hurdle racing in the UK.

Metals’ Role In Odor Sensing

The metal copper allows mice to detect some particularly stinky thiols and related compounds, according to a new report (Proc. Natl. Acad. Sci. USA, DOI: 10.1073/pnas.1111297109). The results put on firm ground long-held suspicions that metals might help humans and animals smell certain volatile chemicals and may force scientists to rethink traditional models of how ligands activate biological receptors. Humans can smell some thiols, which have odors reminiscent of rotten eggs, at levels approaching 1 ppb. Because of this extreme sensitivity, chemists have in the past proposed that metal ions somehow mediate the interaction between these odorants and protein receptors in the nose that send olfactory information to the brain. “They knew that chemicals that bind with metals smell stronger than those that don’t,” explains Hiroaki Matsunami, a neurobiologist at Duke University Medical Center and coauthor of the new study. “This made them think that metal coordination is important to ...

An Exercise Sequence for Progression in Balance Training

Compared with resistance training, information concerning the progressive configuration of balance training (BT) is rare and lacks scientific validation. Therefore, a study was designed to determine participants' ability to perform balance exercises with increasing level of difficulty. The task required the participants (N = 20) to stand as stable as possible on a computerized balance platform. The experiment was performed on 3 testing days using different stance and sensory conditions. On each day, bipedal, step, tandem, and monopedal stands were performed 3 times while sensory conditions changed from firm ground, eyes opened (day 1) over foam ground, eyes opened (day 2) to firm ground, eyes closed (day 3). The results showed that total center of pressure displacements significantly increased when the use of sensory information (comparison between testing days: all p < 0.001) or when the base of support (comparison within testing days: all p < 0.001) was gradually reduced. Based on the observed pattern of increased postural sway across all testing conditions and the levels of trial variability, exercises were categorized into several stages of training. Findings indicate that balance performance decreased in response to an increased level of task difficulty introduced by narrowing the base of support and by limiting the use of sensory information. Practitioners can use the derived exercise ranking to select exercises for BT appropriate to the level of participants' balance ability and to implement progression in balance training.

Expected Performance Functions for Life-Cycle Analysis of Masonry-Infilled Reinforced Concrete Frames

A study is presented about the influence of infill masonry panels on the life-cycle expected performance functions of multi-story reinforced concrete frames exposed to severe seismic hazard conditions. Quantitative information is presented about present values of expected performance functions of a group of five-story systems located at a firm ground site. The group includes a bare frame system, designed in accordance with the applicable seismic design regulations, and a number of systems obtained by inserting several reinforced or unreinforced masonry wall panels, introduced with the aim of improving the expected seismic performance of the original system.

Steering Behavior of a Track-Driven Paintball Robot

Studies on the steering characteristics of track-driven mobile robot have been previously performed in terms of stationary motions at a constant speed. Nevertheless, stationary motions are rather rare and almost all motions of track-driven mobile robot are non-stationary. This work presents an analysis on the steering behaviour of a track-driven paintball robot. A mathematical model of a track-driven platform that allows the study of its curvilinear motion on firm level ground has been developed. The non-linear kinematics model was simulated to predict the steerability of track-driven paintball robot under curvilinear maneuvers at varying initial velocities. The purpose of the modelling is to understand the locomotion and the behavior of the track-driven platform towards the development of an autonomous paintball robot named as the iBOT.

The Serbian Radical Party 1881–1903: Ideology and Its Sources

The Serbian Radical Party 1881–1903:Ideology and Its Sources1 Miroslav Svirčević Introduction Two important aspects of the Serbian Radical Party were its political ideology and its practices. The major tenets of the movement’s ideology were constitutional reform, introduction of parliamentarianism, state organization according to the principle of self-government by local authorities (municipalities and districts), establishment of democracy, including freedom of press, association, and public assembly, and a national program. The major characteristics of the Serbian Radical movement could be summed up as follows: flexibility, pragmatism, cohesion, and the use of demagoguery. Ideological tenets may be inferred from the movement’s political programs, drafts of the constitution, and numerous writings and articles. The characteristics of the movement were shaped by the political reality in which it functioned and struggled to survive. One aspect, the ideological, provided firmness, consistency, and rationale; the other aspect, the practical, ensured popularity, success, and power. Together, they formed the essence of the Serbian Radical movement.2 Each of these elements of the Serbian Radical movement took shape gradually over a period of ideological formation. Once they became fully defined and accepted, the Radical movement had its firm theoretical ground. At this point, it can be classified as a movement of radical-democratic orientation. The national program, another basic aspect of their political ideology, belongs to its external ingredients. Namely, the Radicals viewed national emancipation, [End Page 81] liberation, and unification of the Serbs as originating from internal freedom. In other words, the national program was the result of democratic changes, and not the reverse. Formation of the People’s Radical Party The Serbian Radical movement was politically organized in the form of the People’s Radical Party. The appearance of the party’s newsletter, Samouprava (Self-Government), the day after Christmas (according to the Julian calendar) in 1881, marked the official formation of the first real political party in Serbia, prior to its rival parties: Liberal and Progressive parties. In the first issue of the party’s political, literary, and economic newsletter, the program of the People’s Radical Party was published. It was signed by 38 deputies, with “another 38 fellow deputies” whose names were not disclosed. The Radical program was therefore accepted by 76 members of the Assembly. The publication of the party’s program in the first issue of Samouprava was accompanied by a statement that the signing of the program was open to all members of the Assembly, and “gentlemen who wanted to sign the application form to the Party may do so with the deputy Mr. Nikola Pašić.”3 It seemed that almost all the deputies aligned with the Radicals.4 A group of peasant deputies led by Adam Bogosavljević joined the Radical club. Under their influence, Radicals acquired the character of a class peasant party at the very beginning. In this group, the most loyal peasant tribunes stood out: Ranko Tajsić, Vasa Stošić, Sava and Novak Milošević, etc. They represented a strong left movement among the Radicals that did not want to make any political compromises to anyone.5 Under their influence, the Radicals largely managed to keep their grit and firmness. However, this did not result in a splintering of the party factions. The first splitting of the party followed the Radical-Progressive Agreement of 1901, when the so-called Independent Radicals separated themselves from the Old Radicals—followers of the agreement—and formed a new, separate party. Only the Socialists, led by Dimitrije Cenić (1851–88), did not wish to join the Radicals. On the contrary, they declared political war against the Radicals, accusing them of betraying the socialist program of Svetozar Marković. Cenić and his like-minded group of intellectuals (Dragiša Stanojević, Lazar Nančić) [End Page 82] saw in the Radicals their greatest opponents. Thus, the Radicals and Socialists began a merciless struggle against each other, between the unfaltering followers of an idea and those who were classified as traitors to that idea. The Radicals were sharply criticized by other parties besides the Socialists, mostly by the Progressivists. King Milan Obrenović (1854–1901)6 also joined their critics. He assumed that Radicals had always been an anarchist...

Quantifying dissipative contributions in nanoscale interactions

Imaging with nanoscale resolution has become routine practice with the use of scanning probe techniques. Nevertheless, quantification of material properties and processes has been hampered by the complexity of the tip-surface interaction and the dependency of the dynamics on operational parameters. Here, we propose a framework for the quantification of the coefficients of viscoelasticity, surface energy, surface energy hysteresis and elastic modulus. Quantification of these parameters at the nanoscale will provide a firm ground to the understanding and modelling of tribology and nanoscale sciences with true nanoscale resolution.

The Unreliability of Irenaeus’s Reference to Syneisaktism (Adversus Haereses 1,6,3)

Abstract In modern scholarly research there seems to be a consensus that Irenaeus’s Adversus Haereses 1,6,3 should be interpreted in connection with the ascetic practice of syneis­aktism (“spiritual marriage”). Irenaeus writes that some Valentinians who “pretend at first to live in chastity with them as with sisters, have been proved in the course of time to be in the wrong, when the sister gives birth to a child of her brother”. At first sight this sentence indeed seems to describe a practice in which the living together in chastity is the central focus and a link with syneisaktism is therefore not far-fetched. In this article, however, I present another interpretation. By looking to the content of the text and its context, it will be possible to prove that the paragraph in question is a polemical reproach that does not find any firm ground in the range of thoughts really held by this particular Gnostic movement.

Realismen og det unaturlige

REALISM AND THE UNCANNY. | Maria Mäkelä observes that the emergent trend of unnatural narratology has drawn most of its impetus from the strikingly transgressive, illogical or anti-mimetic elements of narrative construction, and that, consequently, texts that have established the firm ground of literary conventions – such as classical realist novels – have been playing the part of default narratives both in their representational design as well as in their experiential parameters. Mäkelä, howeverP– discussing in this essay salient examples from Dickens, Flaubert, and Tolstoy – finds that narratives under the heading of realism may have even more narratologically transgressive potential than the manifestly anti-experiential or anti-narrative extremes. Mäkelä’s text thus – inspired by some of Viktor Šklovsky’s seminal insights – aims at recovering the unnatural essence of the conventional in narrative fiction.

Infra-red imaging of bulk water and water–solid interfaces under stable and metastable conditions

Superheated water has been studied by infrared spectroscopy to examine whether the special ability of liquid water to undergo such a metastable state corresponds to the development of peculiar inter-molecular networking under tension. As the best technique to superheat water is to trap the liquid inside micro-cavities in solids (the so-called "fluid inclusions"), the role of the water-solid interfaces to stabilize the adjoining liquid is also explored with the same infra-red micro-spectroscopy tool. The key signal is the intra-molecular OH stretching band, sensitive to the networking in the probed material. The sample of choice is liquid water occluded inside a quartz cavity of micrometric size, synthesized in laboratory from pure quartz and milli-Q water. The stretching band of the superheated water shows no significant spectral difference from that of a bulk "normal" water, which means that the molecular properties of the superheating liquid are quite similar to those of the stable bulk liquid. Liquid water is readily "superheatable" but retains its "normality" under these special conditions. Additionally, this result establishes a firm ground to justify that the properties of the former are predicted extrapolating the usual (though empirical) equation of state of the latter. The infra-red signals of the water-solid interfaces are more complex. The water-solid interfaces blue-shift the signal, affecting differently the three sub-bands of the OH-stretching. This effect was unexpected since the micro-IR spectroscopy probes volume beyond what is classically assigned for the interfacial properties. In addition, the interfacial signature is clearer under superheating than under the saturation conditions, which offers an interesting (and unexpected) way to interpret the special stability of the occluded metastable water. These encouraging results give confidence on the potentialities of the high-resolution micro-spectroscopy to get insights into the molecular basis of macroscopic properties.

Developing the e-scape software system

Most innovations have contextual pre-cursors that prompt new ways of thinking and in their turn help to give form to the new reality. This was the case with the e-scape software development process. The origins of the system existed in software components and ideas that we had developed through previous projects, but the ultimate direction we took with e-scape evolved through a sometimes scary but always fascinating collaboration with TERU at Goldsmiths University of London. The literature refers to ‘agile development’ (Highsmith 2002) and it is certainly a good name for the process we undertook with TERU. It is tempting to believe that one can specify a system, agree it with the clients, and then build it. But not so, … or at least not so in this case. We of course did draw up detailed specifications, but as soon as we started to build it, we or the TERU team would see how much better it could be if only we could just …. In the end, understanding of what is required evolves as the understanding of what is possible develops. So specifications morphed from do-able to maybe; from the firm ground of known technologies to the more shaky territory of the half-known and the “I’ve read about that somewhere”. But the underlying reality was always time and money. The system had to work robustly with enough time ahead of the national pilots for the TERU team to do all the necessary trials and training in schools. And it had to be done within fixed costs agreed at the outset. In this paper I outline the principal challenges that we met along the way and summarise our approach to resolving them.

The Sorites is nonsense disguised by a fallacy

It is uncontroversial that, on any run through a Sorites series, a subject, at some point, switches from an ‘F’ verdict on one exhibit to a non-‘F’ verdict on the next. (Where this ‘cut-off’ point occurs tends to differ from trial to trial.) It is a fallacy to infer that there must be a cut-off point simpliciter between F items and non-F items. The transition is from firm ground to swamp. In the Sorites reasoning, some conditionals of the form ‘If Item n is F, then Item n+1 is F’ are not false but nonsensical. This solution respects boundarylessness.

From Microscopy to Whole Slide Digital Images

In the year 1850, microscopes had evolved in quality to the point that the "first pathologists emerged from the treacherous swamps of medieval practice onto the relatively firm ground that histopathology seemed to offer." These early pathologists began to practice the art of image analysis, and diagnostic surgical pathology was born. Today the traditional microscope, in the hands of an experienced pathologist, is established as the gold standard for diagnosis of cancer and other diseases. Nonetheless, it is a tool and a technology that is more than 150 years old. Rapid advances in the capabilities of digital imaging hardware and software now offer the real possibility of moving to a new level of practice, using whole slide digital images for diagnosis, education, and research in morphologic pathology. Potential efficiencies in work flow and diagnostic integration, coupled with the use of powerful new analytic methods, promise radically to change the future shape of surgical pathology.