bluuebunny/crossref_metadata_2025 huggingface dataset:
Spinal Cord Injury: Time to Move?
Authors: Rossignol Serge , Schwab Martin , Schwartz Michal , Fehlings Michael G.
Published: October 2007

This symposium aims at summarizing some of the scientific bases for current or planned clinical trials in patients with spinal cord injury (SCI). It stems from the interactions of four researchers involved in basic and clinical research who presented their work at a dedicated Symposium of the Society for Neuroscience in San Diego. After SCI, primary and secondary damage occurs and several endogenous processes are triggered that may foster or hinder axonal reconnection from supralesional structures. Studies in animals show that some of these processes can be enhanced or decreased by exogenous interventions using drugs to diminish repulsive barriers (anti-Nogo, anti-Rho) that prevent regeneration and/or sprouting of axons. Cell grafts are also envisaged to enhance beneficial immunological mechanisms (autologous macrophages, vaccines) or remyelinate axons (oligodendrocytes derived from stem cells). Some of these treatments could be planned concurrently with neurosurgical approaches that are themselves beneficial to decrease secondary damage (e.g., decompression/reconstructive spinal surgery). Finally, rehabilitative approaches based on the presence of functional networks (i.e., central pattern generator) below the lesion combined with the above neurobiological approaches may produce significant functional recovery of some sensorimotor functions, such as locomotion, by ensuring an optimal function of endogenous spinal networks and establishing new dynamic interactions with supralesional structures. More work is needed on all fronts, but already the results offer great hope for functional recovery after SCI based on sound basic and clinical neuroscience research.
Biomimetic Brain Machine Interfaces for the Control of Movement
Authors: Fagg Andrew H. , Hatsopoulos Nicholas G. , de Lafuente Victor , Moxon Karen A. , Nemati Shamim , Rebesco James M. , Romo Ranulfo , Solla Sara A. , Reimer Jake , Tkach Dennis , Pohlmeyer Eric A. , Miller Lee E.
Published: October 2007

Quite recently, it has become possible to use signals recorded simultaneously from large numbers of cortical neurons for real-time control. Such brain machine interfaces (BMIs) have allowed animal subjects and human patients to control the position of a computer cursor or robotic limb under the guidance of visual feedback. Although impressive, such approaches essentially ignore the dynamics of the musculoskeletal system, and they lack potentially critical somatosensory feedback. In this mini-symposium, we will initiate a discussion of systems that more nearly mimic the control of natural limb movement. The work that we will describe is based on fundamental observations of sensorimotor physiology that have inspired novel BMI approaches. We will focus on what we consider to be three of the most important new directions for BMI development related to the control of movement. (1) We will present alternative methods for building decoders, including structured, nonlinear models, the explicit incorporation of limb state information, and novel approaches to the development of decoders for paralyzed subjects unable to generate an output signal. (2) We will describe the real-time prediction of dynamical signals, including joint torque, force, and EMG, and the real-time control of physical plants with dynamics like that of the real limb. (3) We will discuss critical factors that must be considered to incorporate somatosensory feedback to the BMI user, including its potential benefits, the differing representations of sensation and perception across cortical areas, and the changes in the cortical representation of tactile events after spinal injury.
Evidence Accumulation and the Moment of Recognition: Dissociating Perceptual Recognition Processes Using fMRI
Authors: Ploran Elisabeth J. , Nelson Steven M. , Velanova Katerina , Donaldson David I. , Petersen Steven E. , Wheeler Mark E.
Published: October 2007

Decision making can be conceptualized as the culmination of an integrative process in which evidence supporting different response options accumulates gradually over time. We used functional magnetic resonance imaging to investigate brain activity leading up to and during decisions about perceptual object identity. Pictures were revealed gradually and subjects signaled the time of recognition (TR) with a button press. We examined the time course of TR-dependent activity to determine how brain regions tracked the timing of recognition. In several occipital regions, activity increased primarily as stimulus information increased, suggesting a role in lower-level sensory processing. In inferior temporal, frontal, and parietal regions, a gradual buildup in activity peaking in correspondence with TRsuggested that these regions participated in the accumulation of evidence supporting object identity. In medial frontal cortex, anterior insula/frontal operculum, and thalamus, activity remained near baseline until TR, suggesting a relation to the moment of recognition or the decision itself. The findings dissociate neural processes that function in concert during perceptual recognition decisions.
Noncoding RNAs in the Brain
Authors: Satterlee John S. , Barbee Scott , Jin Peng , Krichevsky Anna , Salama Sofie , Schratt Gerhard , Wu Da-Yu
Published: October 2007

Cells transcribe thousands of RNAs that do not appear to encode proteins. The neuronal functions of these noncoding RNAs (ncRNAs) are for the most part not known, but specific ncRNAs have been shown to regulate dendritic spine development, neuronal fate specification and differentiation, and synaptic protein synthesis. ncRNAs have been implicated in a number of neuronal diseases including Tourette's syndrome and Fragile X syndrome. Future studies will likely identify additional neuronal functions for ncRNAs as well as roles for these molecules in other neuropsychiatric and neurodevelopmental disorders.
The Structural and Functional Differentiation of Hair Cells in a Lizard's Basilar Papilla Suggests an Operational Principle of Amniote Cochleas
Authors: Chiappe M. Eugenia , Kozlov Andrei S. , Hudspeth A. J.
Published: October 2007

The hair cells in the mammalian cochlea are of two distinct types. Inner hair cells are responsible for transducing mechanical stimuli into electrical responses, which they forward to the brain through a copious afferent innervation. Outer hair cells, which are thought to mediate the active process that sensitizes and tunes the cochlea, possess a negligible afferent innervation. For every inner hair cell, there are approximately three outer hair cells, so only one-quarter of the hair cells directly deliver information to the CNS. Although this is a surprising feature for a sensory system, the occurrence of a similar innervation pattern in birds and crocodilians suggests that the arrangement has an adaptive value. Using a lizard with highly developed hearing, the tokay gecko, we demonstrate in the present study that the same principle operates in a third major group of terrestrial animals. We propose that the differentiation of hair cells into signaling and amplifying classes reflects incompatible strategies for the optimization of mechanoelectrical transduction and of an active process based on active hair-bundle motility.
Synaptic Plasticity (and the Lack Thereof) in Hippocampal CA2 Neurons
Authors: Zhao Meilan , Choi Yun-Sik , Obrietan Karl , Dudek Serena M.
Published: October 2007

The hippocampus is critical for some forms of memory and spatial navigation, but previous research has mostly neglected the CA2, a unique region situated between CA3 and CA1. Here, we show that CA2 pyramidal neurons have distinctive physiological characteristics that include an unprecedented synaptic stability. Although basal synaptic currents in CA1 and CA2 are quite similar, synaptic plasticity including long-term potentiation and long-term depression is absent or less likely to be induced with conventional methods of stimulation in CA2. We also find that CA2 neurons have larger leak currents and more negative resting membrane potentials than CA1 neurons, and consequently, more current is required for action potential generation in CA2 neurons. These data suggest that the molecular “conspiracy against plasticity” in CA2 makes it functionally distinct from the other hippocampal CA regions. This work provides critical insight into hippocampal function and may lead to an understanding of the resistance of CA2 to damage from disease, trauma, and hypoxia.
Spatial Contingencies in Thucydides'History
Authors: Bassi Karen
Published: October 2007

Abstract This paper argues that spatial contingencies, defined by the relationship between where historical actors are in the narrative and what they say, are crucial for understanding the political and ideological effects of Thucydides' History. A comprehensive approach to these contingencies is linked to two related premises. First, that the city of Athens is the principal spatial referent in the History and, second, that Athens refers both to a set of “real” topographical features and to a transcendent and trans-historical ideal that exceeds those features. The dynamic between these two is mediated by Athens' inevitable defeat and by the related conflict between the History as the presentation of facts about the past, on the one hand, and as the source of future predictions, on the other. Framing this analysis are the distinctive characteristics ascribed to the Athenians as a collective and to the positions of Thucydides and Alcibiades as Athenians in exile.
The Specters of Roman Imperialism: The Live Burials of Gauls and Greeks at Rome
Authors: Várhelyi Zsuzsanna
Published: October 2007

Abstract Scholarly discussions of the live burials of Gauls and Greeks in the Forum Boarium in the mid- and late Republic (attested for the years 228, 216, and 114/113 B.C.E.) replay the debate on Roman imperialism; those supporting the theory of “defensive” imperialism connect religious fears with military ones, while other scholars separate this ritual and the “enemy nations” involved in it from the actual enemies of current warfare in order to corroborate a more aggressive sense of Roman imperialism. After reviewing earlier interpretations and the problems of ancient evidence for these Roman instances of “human sacrifice,” I propose a new reading based on a ritual parallel, a slightly earlier Greek oracle related to purification from avenging spirits. As burials of symbolic former enemies haunting Rome, the ritual suggests an insight into the experience of constant warfare and close-contact killing by citizen-soldiers in an aggressively imperialistic state. Especially with the disappearance of captive killings in the symbolic context of aristocratic burials and the emergence of Hellenistic epic to address elite glory, the live burials could have been critical in providing psychological closure to the once-soldiers back in Rome. Remarkably, the ritual offered an outlet in the religious realm for sentiments unwelcome in the Roman army: in the larger dynamic of the military and religious spheres, the strict world of military discipline was complemented by a religious (and cultural) realm that was much more open to external influence and innovation.
The Golden Bowl: Thoughts on the New Sappho and its Asianic Background
Authors: Watkins Calvert
Published: October 2007

Abstract The paper explores the relation between a set of poetic formulas in early Greek and Anatolian languages of the second and early first millennia having to do with the cosmography of the rising sun in macrocosm, and going up into bed in microcosm, with an eye to defending the reading and restoration έρωι δέπασ εισομβάμεν(αι) in the editio princeps of the new Sappho. The Luvian word for “sky, heaven,” represented as a bowl in Hieroglyphic, is the likeliest source of the Greek word depas, Mycenean dipas, in the second millennium, together with the associative semantics of depas and “heaven” evidenced in Hittite and Luvian texts in the second millennium, and in early Greek poetry in the first.
Critical Therapeutics: Cultural Politics and Clinical Reality in Two Eating Disorder Treatment Centers
Authors: Lester Rebecca J.
Published: October 2007

Recent studies suggest that eating disorders are increasing in Mexico and that this seems to correspond with Mexico's push to modernization. In this respect, Mexico exemplifies the acculturation hypothesis of eating disorders, namely, that anorexia and bulimia are culture‐bound syndromes tied to postindustrial capitalist development and neoliberalist values, and that their appearance elsewhere is indicative of acculturation to those values. Available evidence for this claim, however, is often problematic. On the basis of five years of comparative fieldwork in eating disorder clinics in Mexico City and a small Midwestern city in the United States, I reframe this as an ethnographic question by examining how specific clinical practices at each site entangle global diagnostic categories with local social realities in ways that problematize existing epistemologies about culture and illness. In this regard, debates about acculturation and the global rise of eating disorders foreground issues of central epistemological and practical importance to contemporary medical anthropology more generally.
Picturing Personhood: Brain Scans and Biomedical Identity
Authors: Braitberg Victor
Published: October 2007

Picturing Personhood: Brain Scans and Biomedical Identity. Joseph Dumit. Princeton: Princeton University Press, 2004. xii. 272 pp.
Menopause: A Biocultural Perspective
Authors: Kirchengast Sylvia
Published: October 2007

Menopause:. Biocultural Perspective. Lynette Leidy Sievert. New Brunswick, NJ: Rutgers University Press, 2006, ix. 220 pp.
The Evolution of Mind
Authors: Qirko Hector
Published: October 2007

The Evolution of Mind. Steven W. Gangestad and Jeffry A. Simpson, eds. New York: Guilford Press 2007; 448 pp.
The Secret Downing Street Memo, the One Percent Doctrine, and the Politics of Truth: A Performance Text
Authors: Denzin Norman K.
Published: October 2007

Presented to the Society for the Study of Symbolic Interaction in Montreal, Canada, on August 7, 2006, this performance text is a critique of the Bush administration and its reliance on science, or evidence‐based models of inquiry (SBR). SBR raises issues concerning the politics of truth and evidence. These issues intersect with the ways in which a given political regime fixes facts to fit ideology. Three versions of SBR are discussed. A model of science as disruptive cultural practice is outlined. I locate the interactionist project in the discourses surrounding the global war on terror and the war in Iraq. I conclude by calling for a merger of critical pedagogy with a prophetic, feminist postpragmatism.
The Social Logic of “False Memories”: Symbolic Awakenings and Symbolic Worlds in Survivor and Retractor Narratives
Authors: DeGloma Thomas
Published: October 2007

Taking an interactionist, narrative approach to psychology's “memory wars,” I analyze the accounts of self‐identified survivors of childhood sexual abuse (traditionally emphasized by “recovered” memory advocates) and the accounts of retractors—those who reject their former memories of childhood sexual abuse (traditionally emphasized by “false” memory advocates). Although typically held to be oppositional, both groups conform to similar patterns of storytelling. Both survivors and retractors use scripted symbolic awakenings to account for their past mnemonic “errors” and their more recent discovery of “truth.” Such symbolic awakenings are important mechanisms of mnemonic and autobiographical revision. Further, both groups use vocabularies of cognitive constraint to claim that cognitive authority figures once controlled their ability to interpret and remember their experiences. I approach the question of childhood sexual abuse and memory with attention to the distinctly social influences on cognition. I argue that the experiences of recovering and retracting memories involve similar social processes of remembering and storytelling.
Electrostatic force microscopy studies of boron-doped diamond films
Authors: Gupta S. , Williams O.A. , Bohannan E.
Published: October 2007

Much has been learned from electrochemical properties of boron-doped diamond (BDD) thin films synthesized using microwave plasma-assisted chemical vapor deposition about the factors influencing electrochemical activity, but some characteristics are still not entirely understood, such as its electrical conductivity in relation with microscale structure. Therefore, to effectively utilize these materials, understanding both the microscopic structure and physical (electrical, in particular) properties becomes indispensable. In addition to topography using atomic force microscopy, electrostatic force microscopy (EFM) in phase mode measuring the long-range electrostatic force gradients, helps to map the electrical conductivity heterogeneity of boron-doped micro-/nanocrystalline diamond surfaces. The mapping of electrical conductivity on boron doping and bias voltage is investigated. Experimental results showed that the BDD films’ surfaces were partially rougher with contrast of conductive regions (areas much less than 1 μm2 in diameter), which were uniformly distributed. Usually, the EFM signal is a convolution of topography and electrostatic force, and the phase contrast was increased with boron doping. At the highest boron doping level, the conductive regions exhibited quasi-metallic electrical properties. Moreover, the presence of a “positive–negative–positive” phase shift along the line section indicates the presence of “insulating–conducting–insulating” phases, although qualitative. Furthermore, the electrical properties, such as capacitance and dielectric constants at operating frequency, were quantitatively evaluated through modeling the bias-dependent phase measurements using simple and approximate geometries. It was found that decreasing grain size (or increasing the boron concentration) lowers the dielectric constant, which is attributed to the change in the crystal field caused by surface bond contraction of the nanosized crystallites. These findings are complemented and validated with scanning electron microscopy, x-ray diffraction, and “visible” Raman spectroscopy revealing their morphology, structure, and carbon-bonding configuration (sp3 versus sp2), respectively. These results are significant in the development of electrochemical nano-/microelectrodes and diamond-based electronics.
Modulation of MS2 virus adsorption on TiO2semiconductor film by nitrogen doping
Authors: Li Qi , Liang Wei , Shang Jian Ku
Published: October 2007

Nitrogen was doped into titanium dioxide film to alter its surface electrostatic properties, and subsequently modulate the interaction force between MS2 virus and semiconductor films for control of the adsorption behavior of MS2 on semiconductor surfaces. By combining atomic force microscopy (AFM) height profile and phase profile, adsorptions of MS2 virus on TiO2-based semiconductor surfaces were observed in solutions over a range of pH values. The adsorption behavior was shown to agree with the theoretical analysis of colloidal interactions.
Self-organized TiO2nanotube arrays by anodization of Ti substrate: Effect of anodization time, voltage and medium composition on oxide morphology and photoelectrochemical response
Authors: Watcharenwong A. , Chanmanee W. , de Tacconi N.R. , Chenthamarakshan C.R. , Kajitvichyanukul P. , Rajeshwar K.
Published: October 2007

This study probes the relationship between the morphology of anodic titania (TiO2) layers grown on Ti foil substrates and their subsequent photoelectrochemical response in 0.5 M Na2SO4supporting electrolyte. The effects of anodization variables (voltage and time) and anodization medium composition [water, glycerol, poly(ethylene glycol), ethylene glycol] along with fluoride ion concentration on the oxide layer of morphology and photoresponse are described. The degree of order of the self organized TiO2nanotube arrays and the extent to which these arrays organize themselves over the entire substrate surface are key variables dictating the corresponding quality of the resultant photoresponse.
Light absorptive underlayer enhanced excimer-laser crystallization of Si thin-film
Authors: Yeh Wenchang , Ke Dunyuan , Zhuang Chunjun , Huang Hsiangen , Yang Yubang
Published: October 2007

A sample structure and method for superlateral-growth (SLG) enhancement in excimer-laser crystallization has been implemented and realized. The proposed sample structure is a Si film/buffer film/light-absorptive (LA) film/glass-stacked structure, with the irradiation of laser light from underneath a substrate. The influence of the absorption coefficient α of the LA film has been found to be critical in this structure. By increasing α from 0 to 12,000 cm−1, diameter of SLG grain has increased from 0.8 to 10 μm, with the solidification term increased from 75 to 1050 ns, respectively. The radius of SLG grain was shown to be proportional to the solidification term with a slope of 5 m/s. This result suggests the average SLG growth rate is constant at 5 m/s, irrespective of the solidification term of Si film. The applicability of present method to both sequential lateral solidification method and micromelt seeding method was demonstrated. Overcoming of Si agglomeration has been shown to be important for applying the present method to the sequential lateral solidification (SLS) method.
Thermodynamic description of the Cu–Sn system
Authors: Gierlotka Wojcieh , Chen Sinn-wen , Lin Shih-kang
Published: October 2007

The Cu–Sn binary system is important for various applications, especially for recent developments in the electronics packaging industry. The ϵ-Cu3Sn and η-Cu6Sn5 (η′ phases) phases are frequently encountered in electronics products. However, the two phases have been described as line compounds in previous thermodynamic modeling, and their compositional homogeneities were not considered. In this study, the thermodynamic properties of the Cu–Sn binary system are modeled and the phase diagram is calculated by the CALPHAD method, using experimental information reported in the literature. The ϵ and η (η′) phases are described using compound energy models with two and three sublattices, respectively, so that their compositional homogeneities could be calculated. Good agreement was observed between the calculated result and the existing experimental data.
On the cyclic indentation behavior of crystalline silicon with a sharp tip
Authors: Fujisawa N. , Williams J.S. , Swain M.V.
Published: October 2007

Detailed cyclic indentation experiments of crystalline silicon in this study show interesting behavior depending on the end phase from the previous cycle. To enable the behavior of these phases to be studied on reloading, the cyclic indentation response of the material is examined under conditions where the pressure-induced Si-II phase transforms either to amorphous (a-Si) or high pressure Si-XII/Si-III phases on unloading. For an amorphous end phase the subsequent reloading is hysteretic, and for high pressure crystalline end phases it is elastic. This indicates that, whereas a-Si re-transforms readily to Si-II upon reloading, Si-XII/Si-III does not retransform to Si-II even at the maximum indentation load. Based on the concept of the effective indenter shape and stresses induced in the material, we show that Si-XII/Si-III has a greater critical hydrostatic pressure for retransformation to Si-II than that of the diamond cubic Si-I.
Preparation of hexagonal cerium oxide nanoflakes by a surfactant-free route and its optical property
Authors: Yu X. , Ye P. , Yang L. , Yang S. , Zhou P. , Gao W.
Published: October 2007

Hexagonal cerium oxide nanoflakes have been synthesized by using a surfactant-free route. Transmission electcron microscopy (TEM), x-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetric and differential thermal analysis (TG-DTA), Brunauer–Emmett–Teller adsorption isotherm (BET), photoluminescence (PL), and ultraviolet–visible (UV–VIS) were used to characterize the sample. The mean size of the nanoflakes is about 30 nm and the specific surface is about 70.08 m2·g−1 when annealed at 400 °C. The acidity and superfluous NH4NO3 play a key role on the formation of nanoflakes in which there exists Ce (IV) and very little Ce (III). The nanoflakes exhibit a wide PL emission peak among 350–400 nm, strong absorption ranged from 200–450 nm, and strong reflection in the visible region. As the sizes of as-prepared samples decrease, a clear blue shift in the absorbing edge is observed. The linear relationship between ΔEg and D is shown in a log–log plot. The as-prepared cerium oxide nanoflakes can be widely used as UV absorbent and polishing materials.
On the exclusive growth of external chromia scale on the novel electrodeposited Cu–Ni–Cr nanocomposites
Authors: Huang Z. , Peng X. , Xu C. , Wang F.
Published: October 2007

Novel metal-matrix nanocomposites (MMNCs) of Cu–30Ni–20Cr and Cu–50Ni–20Cr (by wt%), having a nanocrystalline Cu–Ni solid solution matrix with the dispersion of Cr nanoparticles, were fabricated by coelectrodeposition. Both nanocomposites exclusively grew external chromia scale during oxidation at 800 °C in air. The codeposited Cr nanoparticles, together with the numerous grain boundaries in the Cu–Ni matrix, promoted the establishment of a continuous chromia scale during the initial and transient oxidation stage, and then they functioned as “a reservoir” supplying sufficient Cr flux for the exclusive growth of the scale during the steady-state stage. The theoretical treatment using a two-phase alloy oxidation model indicates that high Cr diffusivity correlated with the persistence of an ultrafine-grained structure of the Cu–Ni matrix during oxidation is crucial to the exclusive chromia growth. Ni content increase did not significantly affect the chromia scale formation. This is fundamentally different from the oxidation of conventional Cu–Ni–Cr alloys investigated for comparison.
A Tale of Two Middle Schools: The Differences in Structure and Instruction
Authors: Fisher Douglas , Frey Nancy
Published: October 2007

In this exploration of school improvement work, two teachers at two schools worked hard to improve literacy achievement, but the performance at only one of the schools resulted in significant growth. By spending time observing classrooms and interacting with students, the authors believe that two factors made the difference: school structures and instructional procedures. The more successful school used time to their advantage and agreed to specific content literacy strategies that were used across the school day to develop students' thinking skills.
New recumbent echinoderm genera from the Bois d'Arc Formation: Lower Devonian (Lochkovian) of Coal County, Oklahoma
Authors: Parsley Ronald L. , Sumrall Colin D.
Published: October 2007

An echinoderm fauna from the Lower Devonian (Lochkovian) Cravatt Member of the Bois d'Arc Formation near Clarita, Oklahoma, has yielded specimens of recumbent, essentially bilaterally symmetrical taxa which are similar to Ordovician genera but absent or sparsely represented in Silurian strata.Claritacarpus smithin. gen. and sp., is a dendrocystitid homoiostele with morphology similar to the Late OrdovicianDendrocystoidesJaekel, 1918; the anomalocystitid stylophoranVictoriacystisaff.holmesorumRuta and Jell, 1999 shows strong affinities toVictoriacystis holmesorumRuta and Jell, 1999, Humevale Formation, of Victoria, Australia; and the pleurocystitid rhombiferan,Turgidacystis graffhamin. gen. and sp., has close affinities to the Middle OrdovicianCoopericystisParsley, 1970 of West Virginia andHenicocystisJell, 1983 of Victoria, Australia.ClaritacarpusandTurgidacystisare North American range extensions for homoiosteles and pleurocystitids, respectively, being previously unknown from rocks younger than Upper Ordovician. Globally, Silurian homoiosteles and pleurocystitids are unknown although both occur in the Lower Devonian of Germany and Australia; additionally, Early Devonian pleurocystitids are known from Great Britain and Bohemia. These genera illustrate a pseudoextinction pattern suggesting a significant unsampled Silurian “homalozoan” and pleurocystitid history.
Basal sauropodomorphs (Dinosauria: Saurischia) from the Lower Jurassic of India: their anatomy and relationships
Authors: Kutty T. S. , Chatterjee Sankar , Galton Peter M. , Upchurch Paul
Published: October 2007

The Upper Dharmaram Formation (Lower Jurassic, Sinemurian) of India has yielded three sauropodomorph dinosaurs, two new taxa and an indeterminate one.Lamplughsaura dharmaramensisn. gen. and sp., represented by several partial skeletons, is a heavily built quadrupedal form (body length ~10 m). Autapomorphies include teeth with strongly emarginated distal edge; caudal cervical neural spines bearing a vertically oriented ligamentous furrow on cranial and caudal surfaces and a transversely expanded spine table; caudal neural spines bearing a craniodorsally directed spur (proximal caudal vertebrae) or a large process (midcaudal vertebrae); caudal neural spines shorter than transverse processes so former lost first in passing along tail; and a plesiomorphy that is the nontrenchant form of manual ungual I. The Indian dinosaurs were coded for two recent datamatrices for basal sauropodomorphs. The results of this preliminary analysis indicate thatLamplughsaurais either a basal Sauropoda or, less likely, based on Templeton's test, a stem sauropodomorph. The second large form, represented by the proximal half of a femur, is a sauropodomorph that is more derived thanSaturnalia(Brazil) andThecodontosaurus(Great Britain) from the Upper Triassic. This is also true for the smaller (body length ~4 m as adult)Pradhania gracilisn. gen. and sp. which lies outside of the Sauropoda + Plateosauria clade, so it is definitely a stem sauropodomorph.Pradhaniais known from fragmentary material; an autapomorphy is the very prominent medial longitudinal ridge on the maxilla.
The Oldest Bryozoans: New Evidence From the Late Tremadocian (Early Ordovician) of East Yangtze Gorges in China
Authors: Xia Feng-Sheng , Zhang Sen-Gui , Wang Zong-Zhe
Published: October 2007

Previous reports of Cambrian bryozoans have proved not to be bryozoans. No pre-Ordovician bryozoans have been recognized. The oldest unequivocal bryozoans known from North America, Britain, and Russia are evidently of early Arenigian age. New bryozoans recently collected from the Fenxiang Formation in the Daping and Guanzhuangping sections, situated in the area east of the Yangtze Gorges, are described here, including one new genus,Orbiramus, and six new species,Nekhorosheviella nodulifera, N. semisphaerica, Orbiramus normalis, O. ovalis, O. minus, andProphyllodictya prisca.These are assigned to the Trepostomida, apart from the last species which belongs to the Cryptostomida. The new bryozoans are from the conodontPaltodus deltifer deltiferZone of the late Tremadocian age, the first three species possibly being present in theP. deltifer pristinusSubzone at the base. Therefore, they are the oldest bryozoans known from anywhere in the world. Extensive reefs resulting from a major regression in the late Tremadocian were dominated by bryozoans in the upper Fenxiang Formation. The bryozoans lived in a shoal environment and accumulated essentially in situ, showing no signs of significant transportation.
Implications of a new species of the Oligo-Miocene kangaroo (Marsupialia: Macropodoidea)Nambaroo, from the Riversleigh World Heritage Area, Queensland, Australia
Authors: Kear Benjamin P. , Cooke Bernard N. , Archer Michael , Flannery Timothy F.
Published: October 2007

A partial skeleton (including both skull and postcranium) and referred dental material attributable to a new species of Oligo-Miocene kangaroo,Nambaroo gillespieae, are described from the Riversleigh World Heritage Area, northwestern Queensland, Australia. The holotype specimen is one of the oldest articulated fossil kangaroo skeletons yet discovered and includes the first postcranial material definitively attributable to the extinct family Balbaridae. Functional-adaptive analysis (including comparisons with modern taxa) of the hindlimb and pedal elements suggests consistent use of quadrupedal progression rather than true hopping. Robust forelimbs and an opposable first pedal digit (lost in most macropodoids) might also indicate limited climbing ability. Cladistic analysis of 104 discrete cranio-dental and postcranial characters coded for 25 ingroup and one outgroup taxon placesN. gillespieaein a plesiomorphic sister clade (also containing other Balbarids and the propleopineEkaltadeta ima) to all other macropodoids. This result supports recent revisions to the classification of kangaroos, which recognize Balbaridae as the most basal macropodoid family-level taxon.
The application of filtration theory to food gathering in Ordovician crinoids
Authors: Brower James C.
Published: October 2007

Food gathering of some adult Upper Ordovician crinoids was modeled by means of filtration theory. The arm-branching patterns of the 13 species examined range from nonpinnulate isotomous arms to uniserial and biserial arms with numerous pinnules. Most taxa are roughly equivalent with respect to ambient current velocities and the nutrient contents needed from seawater. Two species with extensively branched arms have markedly higher nutritional requirements at any one ambient current velocity. The results are somewhat correlated with environment in the form of differential current velocities, water flow patterns, and food abundance and composition. The data are generally compatible with filtration theory and the environmental distributions of many Ordovician and other Paleozoic crinoids, and they reveal that Upper Ordovician crinoids had at least partially developed the ecological patterns seen in later Paleozoic crinoids. Various morphological, physiological, and behavioral changes can be employed by crinoids to alter their nutritional balance. The size distributions of food particles that are caught by the crinoids are modeled. These food particle distributions for the Ordovician fossils resemble those of modern crinoids. Relative to the population of food items, the distributions of particles that are trapped are shifted towards larger items because the crinoid filtration nets are more efficient at catching larger particles. Crinoids with relatively open filtration nets and large food-catching tube feet are generalized and feed on a wide range of food particles of a relatively large mean size. The more specialized taxa with extensively branched arms bearing small and closely packed food-catching tube feet are restricted to a more narrow range of smaller food particles.
The ants of the genus Myrmica (Hymenoptera, Formicidae) from Baltic and Saxonian amber (Late Eocene)
Authors: Radchenko Alexander , Dlussky Gennady , Elmes Graham W.
Published: October 2007

In the course of ongoing revision of the ant genus Myrmica Latreille, 1804, we located, in the collections of the Russian and Polish Academies of Sciences, pieces of Baltic Amber (Late Eocene, ca. 40 Ma; earlier this amber was considered to be Oligocene, e.g., see Wheeler, 1915; Larsson, 1978; Bolton, 1995; Dlussky, 1997), that each contained a fossilized specimen of Myrmica. We were also fortunate to be given access to a piece of Saxonian Amber (the same age as Baltic Amber) from the collection of Manfred Kutscher that contained three specimens of Myrmica. Four of the specimens belong to two new species. We describe these below, placing them in context with extant species, and we re-appraise all previously described fossil Myrmica, providing a key to the identification of the five extinct “true” Myrmica species.
The skull ofNothodipoides(Castoridae, Rodentia) and the occurrence of fossorial adaptations in beavers
Authors: Korth William W.
Published: October 2007

The skull and mandible ofNothodipoidesKorth are described. There are a number of adaptations present that are shared with other rodents with tooth-digging behavior (procumbent, elongated, and flattened incisors; anteriorly tilted occipital; strongly arched upper diastema). A new tribe of Castoroidinae, Nothodipoidini, is proposed forNothodipoidesandMicrodipoidesKorth and Stout, based on the fossorial adaptations of the skull, and their generally smaller size. It appears that fossorial adaptations have occurred in castorids at least three times: the Palaeocastorinae (Whitneyan through Arikareean), the primitive beaverMigmacastor(Arikareean), and the Nothodipoidini (late Barstovian through the Clarendonian).
Two Late Ordovician asteroids (Echinodermata) with characters suggestive of early ophiuroids
Authors: Blake Daniel B.
Published: October 2007

Jugiastern. gen. is based on the Upper Ordovician asteroid (Echinodermata)Petraster speciosus; in addition, a second Upper Ordovician occurrence,Phyrtosaster casteri, new gen. and sp., is described. Both species exhibit mouth frame characters suggestive of those long considered typical of early ophiuroids, thereby demonstrating the adaptive versatility and complexity of asterozoan diversification.Jugiasterspecimens also exhibit delicate ambulacral column articulation. The new fossils indicate the need for much further study before early asterozoan history will be well understood.
Embryonic skin from Late Cretaceous Sauropods (Dinosauria) of Auca Mahuevo, Patagonia, Argentina
Authors: Coria Rodolfo A. , Chiappe Luis M.
Published: October 2007

We describe the integumentary anatomy of titanosaur sauropod embryos from the Auca Mahuevo nesting site. Natural (calcitic) casts of the skin show the non-imbricating, tuberculate scales (i.e., tubercles) typical of other non-avian dinosaurs. However, a variety of scale patterns previously unknown for the skin of these animals is reported. The observed integumentary patterns include ground tubercles, large and elongated tubercles, parallel rows of large tubercles, tubercles in rosette-like and flower-like arrangements, and in striate-like rows. Ground tubercles and rosette-like patterns resemble the few examples of skin known for adult sauropods. The former pattern also resembles the arrangement of osteoderms of the armored titanosaurSaltasaurus.Although the embryonic skin does not show definitive evidence of armor, the posthatching development of osteoderms cannot be ruled out. This material, the only available evidence of the embryonic skin of non-avian dinosaurs, contributes significantly to our knowledge of the integumentary morphology of these animals.
A new, phylogenetically significant Early Ordovician asteroid (Echinodermata)
Authors: Blake Daniel B. , Guensburg Thomas E. , Sprinkle James , Sumrall Colin
Published: October 2007

A new monospecific family of asteroids (Echinodermata) is based onEukrinaster ibexensisn. gen. and sp. from the Lower Ordovician of Utah and Nevada.Eukrinaster, Arenig in age, is one of the earliest of known asterozoans. The new, relatively well-preserved fossils yield important information on character state distribution that will be useful for the interpretation of phylogenetic relationships among the three asterozoan classes, the Somasteroidea, Ophiufoidea, and Asteroidea. In addition, overall form is suggestive of certain living asteroids: to the extent that form equates with function, similarities suggest ecologic parallels in these only distantly related asteroids inhabiting ecologically distinct worlds.
Assessing the biodiversity of Ordovician ostracods from the Argentine Precordillera
Authors: Salas María José
Published: October 2007

Ostracod faunas from the Lower to Middle Ordovician rocks of the Argentine Precordillera Basin (Gualcamayo and Las Aguaditas Formations) are studied. A new family, Garcianidae, is erected. One new genus,Jeanvannieria, and six species are recognized, two of which are new (Jachalipisthia bicornataandJeanvannieria bulbosa). The diversity and composition of the Precordilleran ostracods is evaluated on the basis of previous taxonomic analysis and the fauna studied here. The diversity is moderate, with a peak of 50 species during the early Caradoc. The composition of the fauna is characterized by the dominance of podocopes with a high percentage of binodicopes and a lack of palaeocopes, which is in agreement with a deep shelf environment. The carbonate slope setting of the Las Aguaditas Formation is the deepest environment yet found with Ordovician ostracods and records a relatively diverse fauna. The presence ofEctoprimitioidessuggests biogeographic affinities between the Precordillera and Laurentia. The rest of the fauna contains a high percentage of endemic genera and a mixture of genera with several affinities, Baltic, peri-Gondwanan, and Australian.
A Green River (Eocene) polychrotid (Squamata: Reptilia) and a re-examination of iguanian systematics
Authors: Conrad Jack L. , Rieppel Olivier , Grande Lance
Published: October 2007

A pleurodontan iguanian from the Green River Formation (Eocene) is described in detail and named. The new taxon is known only from a single specimen preserving all areas of the body. Although many of the bone surfaces are eroded, almost all of the skeleton is present and some cartilaginous elements are preserved. The new taxon shares important characteristics with the extant anisolepines and leiosaurines, including the morphology and placement of the caudal autotomy planes, the postxiphisternal inscriptional ribs, and notched or fenestrated clavicles that are expanded proximally. This is the earliest complete iguanian known from the Americas and the earliest known iguanian that may be confidently referred to an extant “family.” A phylogenetic analysis including this taxon and other fossil and extant iguanians offers some support for the monophyly of Polychrotidae sensu lato, Tropiduridae sensu lato, and non-acrodont iguanians (Pleurodonta).
First hexactinellid sponge reported from the Upper Triassic Nayband formation of central Iran
Authors: Rigby J. Keith , Senowbari-Daryan B.
Published: October 2007

Sponges, along with scleractinian corals, are among the main reef-building organisms in Triassic reefs. Hypercalcified groups, including the chambered sphinctozoans, and the unchambered inozoans, chaetetids, and spongiomorphids, represent the most abundant Triassic reef-building sponges. Earlier workers have described elements of the latter group as “hydrozoans.” Hexactinellid sponges, abundant in some Permian reefs (e.g., in Texas, Finks, 1960), are rarely known from similar Triassic deposits, in general (Tichy, 1975), and particularly from Upper Triassic stratigraphic units. Hexactinellid sponges have been sporadically reported from well-investigated Upper Triassic reefs in the western Tethyan region (e.g., Keupp et al., 1989). However, a variety of hexactinellid sponges have been reported from Upper Triassic deposits and reefal limestones of the northern and central Tethyan realm (Boiko, 1990; Wu, 1989; Wu and Xiao, 1989; Rigby et al., 1998).
Early orthoceratoid cephalopods from the Argentine Precordillera (Lower-Middle Ordovician)
Authors: Kröger Björn , Beresi Matilde S. , Landing Ed
Published: October 2007

The Early and Middle Ordovician Orthocerida and Lituitida of Precordilleran Argentina are described, and their systematics and paleogeographic significance are revised. These cephalopods show a strong affinity to coeval faunas of North China, suggesting a location of the Precordillera at middle latitudes in the Southern Hemisphere east of the North China block and relatively close to the Gondwanan margin during the early Middle Ordovician. The descriptive terminology of characters of the septal necks, the position and shape of the siphuncule, and the shape of the connecting ring is improved. The distribution of these characters support an emendation of the Baltoceratidae, Sactorthoceratidae, and Proteoceratidae.Brauliocerasn. gen. (Sactorthoceratidae) andPalorthocerasn. gen. (Orthoceratidae) are erected. The new speciesBraulioceras sanjuanense, Eosomichelinoceras baldisii, Gangshanoceras villicumense, and Rhynchorthoceras minorare proposed.Palorthocerasn. gen. from the Lower OrdovicianOepikodus evaeZone represents the earliest known orthocerid.
Problematic macrofossils from Ediacaran successions in the North China and Chaidam blocks: implications for their evolutionary roots and biostratigraphic significance
Authors: Shen Bing , Xiao Shuhai , Dong Lin , Chuanming Zhou , Liu Jianbo
Published: October 2007

Upper Neoproterozoic successions in the North China and nearby Chaidam blocks are poorly documented. North China successions typically consist of a diamictite unit overlain by siltstone, sandstone, or slate. Similar successions occur in Chaidam, although a cap carbonate lies atop the diamictite unit. The diamictites in both blocks have been variously interpreted as Cryogenian, Ediacaran, or Cambrian glacial deposits. In this paper, we describe problematic macrofossils collected from slate of the upper Zhengmuguan Formation in North China and sandstone of the Zhoujieshan Formation in Chaidam; both fossiliferous formations conformably overlie the aforementioned diamictites. Some of these fossils were previously interpreted as animal traces. Our study recognizes four genera and five species—Helanoichnus helanensisYang in Yang and Zheng, 1985,Palaeopascichnus minimusn. sp.,Palaeopascichnus meniscatusn. sp.,Horodyskia moniliformis? Yochelson and Fedonkin, 2000, andShaanxilithescf.ningqiangensisXing et al., 1984. None of these taxa can be interpreted as animal traces. Instead, they are problematic body fossils of unresolved phylogenetic affinities. The fundamental bodyplan similarity betweenHorodyskiaandPalaeopascichnus, both with serially repeated elements, indicates a possible phylogenetic relationship. Thus, at least some Ediacaran organisms may have a deep root becauseHorodyskiaalso occurs in Mesoproterozoic successions.

Among the four genera reported here,PalaeopascichnusPalij, 1976 andShaanxilithesXing et al., 1984 have been known elsewhere in upper Ediacaran successions, including the Dengying Formation (551-542 Ma) in South China. If these two genera have biostratigraphic significance, the fossiliferous units in North China and Chaidam may be upper Ediacaran as well. Thus, the underlying diamictites in North China and Chaidam cannot be of Cambrian age, although their correlation with Ediacaran and Cryogenian glaciations remains unclear. As no other Neoproterozoic diamictite intervals are known in North China and Chaidam, perhaps only one Neoproterozoic glaciation is recorded in that area.
Macropyge (Promacropyge) scandinavica new species; the first macropyginid trilobite recorded from the Furongian of Baltica
Authors: Terfelt Fredrik , Ahlgren John
Published: October 2007

Macropyge(Promacropyge)scandinavicanew species is described from the FurongianPeltura minorZone on northwestern Mount Kinnekulle, southcentral Sweden. It represents the first macropyginid trilobite recorded in Baltica.M.(P.)scandinavicaclosely resembles other species of the same subgenus from southeast China, suggesting a correlation between the ScandinavianP. minorZone and theLotagnostus americanus-Hedinaspis regalisZone of China. The specimens are preserved in two limestone lithologies, interpreted as representing alternating normal and storm deposits, supporting the idea of an intrabasinal paleohigh in Västergötland, southcentral Sweden.