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Basic Types (basic + type)

Distribution by Scientific Domains

Life Sciences	23%
Earth and Environmental Science	19%
Medical Sciences	14%
Humanities and Social Sciences	14%
Engineering	9%

Selected Abstracts

Basic Types and Structural Characteristics of Uplifts: An Overview of Sedimentary Basins in China

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 2 2009
Dengfa HE
Abstract: The uplift is a positive structural unit of the crust It is an important window for continental dynamics owing to its abundant structural phenomena, such as fault, fold, unconformity and denudation of strata. Meanwhile, it is the very place to store important minerals like oil, natural gas, coal and uranium. Giant and large-scale oil and gas fields in China, such as the Daqing Oilfield, Lunnan-Tahe Oilfield, Penglai 19,3 Oilfield, Puguang Gas Field and Jingbian Gas Field, are developed mainly on uplifts. Therefore, it is the main target both for oil and gas exploration and for geological study. The uplift can be either a basement uplift, or one developed only in the sedimentary cover. Extension, compression and wrench or their combined forces may give rise to uplifts. The development process of uplifting, such as formation, development, dwindling and destruction, can be taken as the uplifting cycle. The uplifts on the giant Precambrian cratons are large in scale with less extensive structural deformation. The uplifts on the medium- and small-sized cratons or neo-cratons are formed in various shapes with strong structural deformation and complicated geological structure. Owing to changes in the geodynamic environment, uplift experiences a multi-stage or multi-cycle development process. Its geological structure is characterized in superposition of multi-structural layers. Based on the basement properties, mechanical stratigraphy and development sequence, uplifts can be divided into three basic types , the succession, superposition and destruction ones. The succession type is subdivided into the maintaining type and the lasting type. The superposition type can be subdivided into the composite anticlinal type, the buried-hill draped type, the faulted uplift type and the migration type according to the different scales and superimposed styles of uplifts in different cycles. The destruction type is subdivided into the tilting type and the negative inverted type. The development history of uplifts and their controlling effects on sedimentation and fluids are quite different from one another, although the uplifts with different structural types store important minerals. Uplifts and their slopes are the main areas for oil and gas accumulation. They usually become the composite oil and gas accumulation zones (belts) with multiple productive formations and various types of oil and gas reservoirs. [source]

Dual-band microstrip-line BPFs using tap-coupling resonators

ELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 6 2010
Nobuhiko Okuzaki
Abstract We focused on various dual-band microstrip-line bandpass filters (BPFs) based on tap-coupled resonators. Three types of BPFs, the basic type, multiple-pole type, and wideband type, were proposed and designed by classical filter theory based on the narrowband approximation method. These filters were analyzed by original computation programs and commercial circuit and electromagnetic simulators. The proposed BPFs were then fabricated and measured in the laboratory. The results confirm that the proposed BPFs produce dual passband response, multiple attenuation poles, and wide-passband characteristics. Very good agreement is found between the results of simulations and experiments. © 2010 Wiley Periodicals, Inc. Electron Comm Jpn, 93(6): 25,33, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10212 [source]

Introduction to Flap Movement: Reconstruction of Five Similar Nasal Defects Using Different Flaps

DERMATOLOGIC SURGERY, Issue 2005
Elbert H. Chen MD
Background. There are several options for closure of a given surgical defect after tumor extirpation is confirmed. Flap reconstruction is one of these options. Objective. The purpose of this article is to introduce the three basic types of flap movement: advancement, rotation, and transposition. Methods. Five similar defects located on the nasal sidewall were repaired, each using a different flap design. Results. The optimal flap design for a given defect on a particular patient is based on the answers to a series of questions: Where is the available tissue reservoir? How can tissue be mobilized from the reservoir to cover the defect? How do the resulting tension vectors affect critical structures? Where are the final incision lines? Conclusion. Many factors must be evaluated before determining a method of reconstruction. Flap reconstruction requires a thorough understanding of anatomy and tissue movement. [source]

Endoscopic classification of chronic gastritis based on a pilot study by the research society for gastritis

DIGESTIVE ENDOSCOPY, Issue 4 2002
Michio Kaminishi
Background:,Various types of classification of gastritis have been proposed, but no plausible classification has been available until now. The Research Society for Gastritis performed a pilot study to establish an endoscopic classification, taking into consideration the following: (i) ease of use; (ii) permitting everyone the common image; and (iii) presence of histopathological evidence. Methods:,One hundred and fifty-five patients were enrolled and underwent gastroscopy. Eight basic endoscopic and histological types of gastritis (superficial, hemorrhagic, erosive, verrucous, atrophic, metaplastic, hyperplastic and special types) were defined. Gastritis was endoscopically diagnosed according to the definition of the endoscopic types of gastritis. Four or more biopsy specimens were obtained from the lesser and the greater curvatures of the antrum and the corpus of each patient, and the histological findings of gastritis and Helicobacter pylori infection were assessed. The histological diagnosis of gastritis was made according to the definition of histology types of gastritis. The endoscopic and the histological diagnoses were then compared in a blinded fashion. Results:,Endoscopic diagnosis was 62% as sensitive as histological diagnosis for erosive gastritis, 67% for verrucous gastritis and 84% for atrophic gastritis in the antrum. In superficial gastritis, sensitivity was approximately 25% in the corpus, but only 8% in the antrum. Metaplastic and hyperplastic gastritis were correctly diagnosed only in severe cases. Conclusion:,Five basic types of gastritis (superficial, erosive, verrucous, atrophic and special types) should be employed for the new endoscopic gastritis classification. Metaplastic and hyperplastic gastritis are considered to be subtypes of atrophic gastritis and they should be excluded from the basic endoscopic classification. A new definition of gastritis in the antrum accompanied by redness still remains to be investigated. [source]

Models of reproductive skew: A review and synthesis (Invited Article)

ETHOLOGY, Issue 1 2000
Rufus A. Johnstone
Animal societies vary markedly in reproductive skew, the extent to which breeding is monopolised by dominant individuals. In the last few years, a large number of different models have been developed to explain this variation. Here, I review existing models of reproductive skew, distinguishing between two basic types. Transactional models focus on group stability and the constraints this places on the division of reproduction. Compromise models, by contrast, ignore issues of group stability and view the division of reproduction as the outcome of a conflict in which each group member has a limited or partial ability to enforce its own optimum. I go on to show, however, that the division between transactional and compromise models is somewhat artificial, and that both approaches may be combined in a single, synthetic treatment. Different models of reproductive skew are thus better seen as special cases of a general underlying theory, rather than alternative paradigms. I conclude with a brief discussion of the possibilities and problems of empirically testing this unified theory of skew, and the prospects for future theoretical advances. [source]

Twenty-five strategies for improving the design, implementation and analysis of health services research related to alcohol and other drug abuse treatment

ADDICTION, Issue 11s3 2000
Michael L. Dennis
While some aspects of addiction can be studied in laboratory or controlled settings, the study of long-term recovery management and the health services that support it requires going out into the community and dealing with populations and systems that are much more diverse and less under our control. This in turn raises many methodological challenges for the health service researchers studying alcohol and other drug abuse treatment. This paper identifies some of these challenges related to the design, measurement, implementation and effectiveness of health services research. It then recommends 25 strategies (and key primers) for addressing them: (1) identifying in advance all stakeholders and issues; (2) developing conceptual models of intervention and context; (3) identifying the population to whom the conclusions will be generalized; (4) matching the research design to the question; (5) conducting randomized experiments only when appropriate and necessary; (6) balancing methodological and treatment concerns; (7) prioritizing analysis plans and increasing design sensitivity, (8) combining qualitative and quantitative methods; (9) identifying the four basic types of measures needed; (10) identifying and using standardized measures; (11) carefully balancing measurement selection and modification; (12) developing and evaluating modified and new measures when necessary; (13) identifying and tracking major clinical subgroups; (14) measuring and analyzing the actual pattern of services received; (15) incorporating implementation checks into the design; (16) inc rporating baseline measures into the intervention; (17) monitoring implementation and dosage as a form of quality assurance; (18) developing procedures early to facilitate tracking and follow-up of study participants; (19) using more appropriate representations of the actual experiment; (20) using appropriate and sensitive standard deviation terms; (21) partialing out variance due to design or known sources prior to estimating experimental effect sizes; (22) using dimensional, interval and ratio measures to increase sensitivity to change; (23) using path or structural equation models; (24) integrating qualitative and quantitative analysis into reporting; and (25) using quasi-experiments, economic or organizational studies to answer other likely policy questions. Most of these strategies have been tried and tested in this and other areas, but are not widely used. Improving the state of the art of health services research and bridging the gap between research and practice do not depend upon using the most advanced methods, but rather upon using the most appropriate methods. [source]

Moral prototypes and moral behavior: Specific effects on emotional precursors of moral behavior and on moral behavior by the activation of moral prototypes

EUROPEAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 6 2010
Silvia Osswald
The present studies investigated the extent to which three basic moral prototypes, "just," "brave", and "caring", are related to moral, prosocial behavior. In five studies, we tested (a) whether people would associate three basic types of moral behavior (helping behavior, moral courage, and heroism) with three moral prototypes, and (b) whether specific emotional precursors of moral behavior and moral behavior itself could be promoted by activating the respective moral prototype. As expected, Studies 1,3 revealed that people associated helping behavior with the caring prototype, moral courage with the just prototype, and heroism with the brave prototype. Studies 4 and 5 showed that the activation of the three prototypes differentially influenced emotional precursors of the three types of moral behavior (Study 4) as well as actual moral behavior (Study 5). Thus, the five studies revealed that people associate different moral behaviors with different moral prototypes and that a certain moral behavior can be activated by the priming of the related prototype. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Classifying tagging experiments for commercial fisheries into three fundamental types based on design, data requirements and estimable population parameters

FISH AND FISHERIES, Issue 2 2010
Tom Polacheck
Abstract Mark,recapture experiments have the potential to provide direct estimates of fundamental parameters required for fishery stock assessment and provision of subsequent management advice in fisheries. The literature on mark,recapture experiments is enormous, with a variety of different experimental designs and estimation models; thus, it can be difficult to grasp the primary features of different approaches, the inter-relationship among them and their potential utility in different situations. Here, we present an overview of the tagging experimental designs that are appropriate for use in commercial fishery situations. We suggest that most mark,recapture experiments in a large-scale fishery context can be classified into one of three basic types , Petersen, tag-attrition or Brownie , based on the fundamental design employed for releases and recaptures. The release and recapture strategy (e.g. the number of release events, whether the size of the sample examined for recaptured tags is known) determines which parameters can be estimated and from where the information for estimating them arises. We conclude that an integrated Brownie and Petersen approach is the most powerful of the different approaches in terms of the range of parameters that can be estimated without underlying assumptions or constraints on parameters. Such an approach can provide direct estimates of fishing mortality, natural mortality and population size, which are the main population dynamics parameters that traditional fishery stock assessments attempt to estimate. [source]

Cross-National Concepts in Supranational Governance: State,Society Relations and EU Policy Making

GOVERNANCE, Issue 4 2004
Albert S. YeeArticle first published online: 25 AUG 200
The emergence of multiple and shifting modes of governance both intranationally and supranationally has posed difficulties for analysts accustomed to refining or testing singular types of politics. When confronted with this changing complexity, a comprehensive framework can be a very useful diagnostic and organizational tool. This article devises one such conceptual framework to clarify and systematize varieties of state autonomy and state,society relations. By combining fundamental conceptions of action, elemental control mechanisms, and basic types of interaction, a comprehensive framework is constructed for characterizing and comparing governance modes in a conceptually coherent manner. Many of the abstract spaces within this conceptual field share affinities with types of state autonomy and state,society relations depicted in major theoretical approaches to national politics (i.e., authoritarianism, statism, pluralism, corporatism, institutionalism, and Marxism). This article uses this conceptual framework to systematize these major governance modes and to illuminate their coexistence in supranational governance by examining the European Union policy process. [source]

Memory in the aging brain: Doubly dissociating the contribution of the hippocampus and entorhinal cortex

HIPPOCAMPUS, Issue 11 2007
Andrew P. Yonelinas
Abstract Since the time of Aristotle it has been thought that memories can be divided into two basic types; conscious recollections and familiarity-based judgments. Neuropsychological studies have provided indirect support for this distinction by suggesting that different regions within the human medial temporal lobe (MTL) are involved in these two forms of memory, but none of these studies have demonstrated that these brain regions can be fully dissociated. In a group of nondemented elderly subjects, we found that performance on recall and recognition tests was predicted preferentially by hippocampal and entorhinal volumes, respectively. Structural equation modeling revealed a double dissociation, whereby age-related reductions in hippocampal volume resulted in decreases in recollection, but not familiarity, whereas entorhinal volume was preferentially related to familiarity. The results demonstrate that the forms of episodic memory supported by the human hippocampus and entorhinal cortex can be fully dissociated, and indicate that recollection and familiarity reflect neuroanatomically distinct memory processes. © 2007 Wiley-Liss, Inc. [source]

The training effects of principle knowledge on fault diagnosis performance

HUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 3 2007
Dong-Han Ham
In regard to the effectiveness of types of knowledge on fault diagnosis performance, many experimental studies showed that training with procedural knowledge (diagnostic rules) is very effective to enhance diagnosis performance. But the effects of training with principle knowledge (theoretical knowledge) have been controversial. Some studies went so far as to claim that principle knowledge is not useful for diagnosis. However, common experience suggests that understanding the principles of system dynamics is valuable in certain diagnostic situations. In this study, we conducted an experiment to investigate the value of principle knowledge in various fault situations. A context-free digital logic circuit including 41 gates of three basic types was simulated for the subjects to diagnose. The experimental results showed that instructing principle knowledge has positive effects that are dependent on the complexity of diagnostic problems. The observations also provide insights on how fault diagnosis benefits from principle knowledge. © 2007 Wiley Periodicals, Inc. Hum Factors Man 17: 263,282, 2007. [source]

Designs and analyses of various fuzzy controllers with region-wise linear PID subcontrollers

INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 12 2001
C. W. Tao
To reduce the complexity of PID-like fuzzy controllers with three inputs, designs and analyses of various fuzzy controllers with region-wise linear PID subcontrollers are presented in this paper. The proposed region-wise linear PID subcontrollers are composed of one dimensional fuzzy mechanism. And the triangular-type membership functions are adopted for the input variables of the fuzzy controllers. All the possible structures of fuzzy controllers with region-wise linear PID subcontrollers are discussed. According to the number of one-dimensional fuzzy mechanisms included in the structure of the fuzzy controllers, the fuzzy controllers are classified into three main categories. An algorithm is provided to construct effective fuzzy controllers with lowest complexity among all the possible structures. Also, the properties of various designs of fuzzy controllers with region-wise linear PID subcontrollers are compared. The simulation results are included to demonstrate the performances of three basic types of proposed fuzzy controllers with the linear, nonlinear, and delayed plants. © 2001 John Wiley & Sons, Inc. [source]

Computational verb systems: Verb numbers

INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 5 2001
Tao Yang
In this paper the concepts of (computational) verb number and arithmetical operations of verb numbers are presented. A verb number is a kind of special computational verb, which is derived from structures of (host) verb+(real, interval, fuzzy) number. From the linguistic point of view, a verb number is a computational verb with contexts defined by (real, interval, fuzzy) numbers. Verb numbers can be classified into three basic types based on the outer systems of host verbs. The arithmetic for verb numbers and its rules are presented and proved. If host computational verbs degrade to BE, then verb numbers collapse to real numbers, interval numbers, fuzzy numbers (sets), or other numbers. The set of all verb numbers can be a metric space. The distance between verb numbers can be defined based on the collapses of verb numbers. The cases when verb numbers collapse to triangular fuzzy numbers, trapezoidal fuzzy numbers, and interval numbers are presented and proved. © 2001 John Wiley & Sons, Inc. [source]

Local Governance as Government,Business Cooperation in Western Democracies: Analysing Local and Intergovernmental Effects by Multi-Level Comparison

INTERNATIONAL JOURNAL OF URBAN AND REGIONAL RESEARCH, Issue 3 2008
CLEMENTE J. NAVARRO YÁÑEZ
Abstract The internationalization of economics and politics has forced local governments to develop new context-appropriate strategies; these strategies, characterized by a greater degree of interaction with non-governmental key actors and with the business world in particular, have been termed local or urban governance. This article is intended to illustrate the impact of three factors , local leadership, local political arenas and intergovernmental relationships , on the formation of cooperative networks between local governments and business organizations as one of the basic types of urban governance model. To achieve this, a comparative multi-level analysis presenting the CEO's perpective on such issues was conducted. The results show how local and intergovernmental opportunity costs and leadership are the factors that largely determine the degree of collaboration between local government and business. Résumé L'internationalisation de l'économie et de la politique a forcé les gouvernements locaux àélaborer de nouvelles stratégies en fonction des contextes ; caractérisées par une interaction plus forte avec des acteurs-clés non gouvernementaux et avec le monde de l'entreprise en particulier, ces stratégies ont reçu l'appellation de gouvernance locale ou urbaine. L'impact de trois facteurs , autorité locale, arènes politiques locales et relations intergouvernementales , sur la formation des réseaux de coopération entre gouvernements locaux et entreprises est présenté comme l'un des types essentiels de modèle de gouvernance urbaine. Pour ce faire, une analyse comparative multi-niveaux a été menée sur la vision des directions générales d'entreprises concernant ces questions. Les résultats montrent la manière dont les autorités et les coûts d'opportunité locaux et intergouvernementaux déterminent en grande partie le degré de collaboration entre les gouvernements locaux et le monde des affaires. [source]

The evolution of electroreception and bioelectrogenesis in teleost fish: a phylogenetic perspective

JOURNAL OF FISH BIOLOGY, Issue 6 2001
J. A. Alves-Gomes
According to current phylogenetic theory, both electroreceptors and electric organs evolved multiple times throughout the evolution of teleosts. Two basic types of electroreceptors have been described: ampullary and tuberous electroreceptors. Ampullary-type electroreceptors appeared once in the common ancestor of the Siluriformes+Gymnotiformes (within the superorder Ostariophysi), and on two other occasions within the superorder Osteoglossomorpha: in the African Mormyriformes and in the African Notopteriformes. Tuberous receptors are assumed to have evolved three times; all within groups that already possessed ampullary receptors. With the exception of a single catfish species, for which studies are still lacking, all fish with tuberous electroreceptors also have an electric organ. Tuberous electroreceptors are found in the two unrelated electrogenic teleost lineages (orders Gymnotiformes and Mormyriformes) and in one non-electrogenic South American catfish species (order Siluriformes). Electric organs evolved eight times independently among teleosts: five of them among the ostariophysans (once in the gymnotiform ancestor and in four siluriform lineages), once in the common ancestor of Mormyriformes, and in two uranoscopids. With the exception of two uranoscopid genera, for which no electroreceptive capabilities have been discovered so far, all electric organs evolved as an extension of a pre-existing electroreceptive (ampullary) condition. It is suggested that plesiomorphic electric organ discharges (EODs) possessed a frequency spectrum that fully transgressed the tuning curve of ampullary receptors, i.e. a signal such as a long lasting monophasic pulse. Complex EOD waveforms appeared as a derived condition among electric fish. EODs are under constant evolutionary pressure to develop an ideal compromise between a function that enhances electrolocation and electrocommunication capabilities, and thereby ensures species identity through sexual and behavioural segregation, and minimizes the risk of predation. [source]

A review of penetrometers for subsurface access on comets and asteroids

METEORITICS & PLANETARY SCIENCE, Issue 6 2008
David L. GLASER
Because they offer desirable scientific capabilities and relative mechanical simplicity, penetrators and penetrometers, which use only axial force to push beneath the surface, are a good choice for near-term missions. Penetrometers are instruments, generally deployed from a larger vehicle, that measure subsurface mechanical properties and may also contain additional scientific instruments. There are three basic types: "fast" penetrometers are released from above and plunge into the surface. Static and dynamic (collectively referred to as "slow") penetrometers use, respectively, a constant slow penetration speed and periodic hammering impulses. The low gravity environment of asteroids and comets presents a key challenge to instrument deployment and also greatly affects the mechanical properties of surface materials, and in turn penetrometer performance. The Rosetta mission, currently en route to comet 67P/Churyumov-Gerasimenko, will be the next mission to try both fast and slow, dynamic penetrometry, when it arrives in 2014. We present some new concepts of static penetrometers for small body exploration that are adapted to the low gravity environment. The low gravity environment also presents challenges for the testing of penetrometers on Earth and a number of previous solutions are described and new methods suggested. In the next generation of missions to study comets and asteroids, penetrometers could provide important data on their mechanical, seismic, thermal, electromagnetic, and chemical characteristics, as well as sample collection. [source]

Surface Morphology of the Emu (Dromaius novaehollandiae) Tongue

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 4 2010
M. R. Crole
With 18 figures Summary Despite numerous morphological studies on the avian tongue, very little meaningful information is currently available on the surface features of this organ using scanning electron microscopy (SEM). The only SEM description of a ratite tongue is that of the ostrich, although the descriptions are brief and superficial. This SEM study of the emu tongue confirms and compliments the comprehensive macroscopic and histological data available for this commercially important species. The tongues of five emus were fixed, cut into blocks representing the dorsum, ventrum and root and routinely processed for SEM. Three morphologically distinguishable surface types (desquamating, non-desquamating and lymphoepithelium) related to peculiarities in surface cell shape and status (desquamating or non-desquamating), cell surface modifications and distribution of gland openings, and which showed a regional distribution, could be identified. Three basic types of cell surface modifications (microplicae, microvilli and cilia) were observed, with microvilli and cilia being described for the first time in an avian tongue by SEM. The desquamating surface cells fulfil a mechanical protective function, whereas the microplicae, microvilli and cilia appear to be adaptations for the trapping and spreading of mucus which also fulfils a protective function. [source]

Histochemical properties of skeletal muscles in Japanese cattle and their meat production ability

ANIMAL SCIENCE JOURNAL, Issue 5 2003
Takafumi GOTOH
ABSTRACT The compositional characteristics of the three basic types of myofiber, namely type I (slow-twitch oxidative), type IIA (fast-twitch oxidative glycolytic) and type IIB (fast-twitch glycolytic), are clarified in the skeletal muscles of Japanese Black cattle. The myofiber composition, which is characteristic of the muscles of Japanese Black cattle, markedly changes during their growth, when some type IIA myofibers are transformed into type I or IIB, depending on the different muscles. Independent of these changes with growth, inter- and intramuscular variations of myofiber type distribution is evident. The small extensor muscles in deep regions around bone contain a lot of type I myofibers, whereas the large muscles at surface regions have many type II myofibers. Japanese Black cattle have typical white muscles such as the Longissimus thoracis and Semitendinosus, containing half the myofibers as red (type I + IIA). The muscles of Japanese Black cattle show a tendency to contain a higher percentage of type I myofibers than other breeds over an intrabreed variation of the myofiber type composition. In the big muscles such as the Longissimus thoracis and Biceps femoris, a great diversity of myofiber type composition is observed among the different regions. When fattened, heifers produce Longissimus thoracis and Biceps femoris muscles of smaller weight than steers, but in heifers the myofiber size in each type is rather larger. In the Psoas major, Vastus lateralis and Serratus ventralis muscles, heifers contain a higher frequency of red (type I + IIA) myofibers with no differences in myofiber size. Among the several muscles of fattened Japanese Black steers, the percentage distribution of type I myofibers has a positive correlation with the percentage amount of intramuscular fat. From these results, the high potential of Japanese Black cattle to produce marbled beef could be based on the histochemical properties of myofibers in their skeletal muscles. [source]

MARBLE PROVENANCE INVESTIGATION OF ROMAN SARCOPHAGI FROM THESSALONIKI*

ARCHAEOMETRY, Issue 1 2010
Y. MANIATIS
The provenance question of the marbles used for making the sarcophagi of local production of Thessaloniki in the Roman period had been posed by archaeologists in the past. The hypothesis was that the material came mainly from the quarries of Thassos Island. This paper presents the scientific analysis of 23 characteristic samples from selected sarcophagi at the Museum of Thessaloniki, using three different techniques: electron paramagnetic resonance (EPR) spectroscopy, stable isotope analysis and maximum grain size measurements, plus in-situ examination. New combinations of parameters were used in order to resolve fully the provenance of all samples. The results showed that the vast majority of the objects were indeed made in Thassian marble but from three different quarries, namely Vathy/Saliara (dolomitic marble), Aliki (calcitic marble) and Acropolis/Phanari (calcitic marble). The calcitic marbles from Aliki and to a lesser degree from Acropolis/Phanari are met in all the basic types of sarcophagi (framed type, plain type, garland sarcophagi). The use of the better quality and snow-white dolomitic marble from Vathy/Saliara quarries is relatively restricted and is often found in works that are above the average regarding the quality of their workmanship. In addition, two sarcophagi were made in Pentlelic marble and one in Proconnesian. The scientific analysis results provide a good confirmation of the archaeological estimates and, furthermore, the conclusions constitute henceforth a secure basis for the study of the entire sculptured works of Thessaloniki. [source]

The evolution of arthropod limbs

BIOLOGICAL REVIEWS, Issue 2 2004
Geoff A. Boxshall
ABSTRACT Limb morphology across the arthropods is reviewed using external morphological and internal anatomical data from both recent and fossil arthropods. Evolutionary trends in limb structure are identified primarily by reference to the more rigorous of the many existing phylogenetic schemes, but no major new phylogenetic inferences are presented. Tagmosis patterns are not considered, although the origins and patterns of heteronomy within the postantennulary limb series are analysed. The phenomenon of annulation is examined and two basic types of annuli are recognised: terminal and intercalary. The annulation of the apical segment of a limb results in the formation of terminal flagella, and is typical of primarily sensory appendages such as insect and malacostracan antennules and maxillary palps of some hexapods. Intercalary annulation, arising by subdivision of existing subterminal segments, is common, particularly in the tarsal region of arthropodan walking limbs. Differentiating between segments and annuli is discussed and is recognised as a limiting factor in the interpretation of fossils, which usually lack information on intrinsic musculature, and in the construction of groundplans. Rare examples of secondary segmentation, where the criteria for distinguishing between segments and annuli fail, are also highlighted. The basic crown-group arthropodan limb is identified as tripartite, comprising protopodite, telopodite and exopodite, and the basic segmentation patterns of each of these parts are hypothesised. Possible criteria are discussed that can be used for establishing the boundary between protopodite and telopodite in limbs that are uniramous through loss of the exopodite. The subdivision of the protopodite, which is typical of the postantennulary limbs of mandibulates, is examined. The difficulties resulting from the partial or complete failure of expression of articulations within the mandibulate protopodite and subsequent incorporation of partial proto-podal segments into the body wall, are also discussed. The development and homology between the various exites, including gills, on the postantennulary limbs of arthropods are considered in some detail, and the question of the possible homology between crustacean gills and insect wings is critically addressed. The hypothesis that there are only two basic limb types in arthropods, antennules and postantennulary limbs, is proposed and its apparent contradiction by the transformation of antennules into walking limbs by homeotic mutation is discussed with respect to the appropriate level of serial homology between these limbs. [source]