Magnitude of sex differences in dichotomous ossification sequences of the hand and wrist

Among the dichotomous (present/absent:absent/present) ossinication sequences individually ascertained in 3059 boys and girls with at least one but not more than 27 ossification centers of the hand and wrist, 54 such sequences exhibit statistically-significant sex differences in frequency, 32 of them at the 1% confidence level or better. Analyzed by regions (rows and rays, epiphyses and round bones), ten centers, primarily distals and those of the first digit, account for the majority of the significant sex differences.     

Skeletal heterochrony is associated with the anatomical specializations of snakes among squamate reptiles

Snakes possess a derived anatomy, characterized by limb reduction and reorganization of the skull and internal organs. To understand the origin of snakes from an ontogenetic point of view, we conducted comprehensive investigations on the timing of skeletal elements, based on published and new data, and reconstructed the evolution of the ossification sequence among squamates. We included for the first time Varanus, a critical taxon in phylogenetic context. There is comprehensive delay in the onset of ossification of most skeletal elements in snakes when compared to reference developmental events through evolution. We hypothesize that progressing deceleration accompanied limb reduction and reorganization of the snake skull. Molecular and morphological studies have suggested close relationship of snakes to either amphisbaenians, scincids, geckos, iguanids, or varanids. Likewise, alternative hypotheses on habitat for stem snakes have been postulated. Our comprehensive heterochrony analyses detected developmental shifts in ossification for each hypothesis of snake origin. Moreover, we show that reconstruction of ancestral developmental sequences is a valuable tool to understand ontogenetic mechanisms associated with major evolutionary changes and test homology hypotheses. The “supratemporal” of snakes could be homolog to squamosal of other squamates, which starts ossification early to become relatively large in snakes.     

PATTERNS OF OSSIFICATION IN SOUTHERN VERSUS NORTHERN PLACENTAL MAMMALS

Consensus on placental mammal phylogeny is fairly recent compared to that for vertebrates as a whole. A stable phylogenetic hypothesis enables investigation into the possibility that placental clades differ from one another in terms of their development. Here, we focus on the sequence of skeletal ossification as a possible source of developmental distinctiveness in “northern” (Laurasiatheria and Euarchontoglires) versus “southern” (Afrotheria and Xenarthra) placental clades. We contribute data on cranial and postcranial ossification events during growth in Afrotheria, including elephants, hyraxes, golden moles, tenrecs, sengis, and aardvarks. We use three different techniques to quantify sequence heterochrony: continuous method, sequence‐ANOVA (analysis of variance) and event‐paring/Parsimov. We show that afrotherians significantly differ from other placentals by an early ossification of the orbitosphenoid and caudal vertebrae. Our analysis also suggests that both southern placental groups show a greater degree of developmental variability; however, they rarely seem to vary in the same direction, especially regarding the shifts that differ statistically. The latter observation is inconsistent with the Atlantogenata hypothesis in which afrotherians are considered as the sister clade of xenarthrans. Interestingly, ancestral nodes for Laurasiatheria and Euarchontoglires show very similar trends and our results suggest that developmental homogeneity in some ossification sequences may be restricted to northern placental mammals (Boreoeutheria).     

Ontogenetic Sequence Analysis: using parsimony to characterize developmental sequences and sequence polymorphism

Ontogenetic sequences are a pervasive aspect of development and are used extensively by biologists for intra- and interspecific comparisons. A tacit assumption behind most such analyses is that sequence is largely invariant within a species. However, recent embryological and experimental work emphasizes that ontogenetic sequences can be variable and that sequence polymorphism may be far more prevalent than is generally realized. We present a method that uses parsimony algorithms to map hierarchic developmental patterns that capture variability within a sample. This technique for discovering and formalizing sequences is called the "Ontogenetic Sequence Analysis" (OSA). Results of OSA include formalized diagrams of reticulating networks, describe all most parsimonious sequences, and can be used to develop statistics and metrics for comparison of both intraspecific and interspecific sequence variation. The method is tested with examples of human postnatal skeletal ossification, comprising a time-calibrated data set of human hand and wrist epiphyseal unions, and a longitudinal data set of human wrist ossification. Results illustrate the validity of the method for discovering sequence patterns and for predicting morphologies not represented in analytic samples. OSA demonstrates the potential and challenges of incorporating ontogenetic sequences of morphological information into evolutionary analyses.     

Evolution of Helix Formation in the Ribosomal Internal Transcribed Spacer 2 (ITS2) and Its Significance for RNA Secondary Structures

Helices are the most common elements of RNA secondary structure. Despite intensive investigations of various types of RNAs, the evolutionary history of the formation of new helices (novel helical structures) remains largely elusive. Here, by studying the nuclear ribosomal Internal Transcribed Spacer 2 (ITS2), a fast-evolving part of the eukaryotic nuclear ribosomal operon, we identify two possible types of helix formation: one type is “dichotomous helix formation”—transition from one large helix to two smaller helices by invagination of the apical part of a helix, which significantly changes the shape of the original secondary structure but does not increase its complexity (i.e., the total length of the RNA). An alternative type is “lateral helix formation”—origin of an extra helical region by the extension of a bulge loop or a spacer in a multi-helix loop of the original helix, which does not disrupt the pre-existing structure but increases RNA size. Moreover, we present examples from the RNA sequence literature indicating that both types of helix formation may have implications for RNA evolution beyond ITS2.     

Comprehensive phylogenetic analyses of the Ruppia maritima complex focusing on taxa from the Mediterranean

Recent molecular phylogenetic studies reported high diversity of Ruppia species in the Mediterranean. Multiple taxa, including apparent endemics, are known from that region, however, they have thus far not been exposed to phylogenetic analyses aimed at studying their relationships to taxa from other parts of the world. Here we present a comprehensive phylogenetic analyses of the R. maritima complex using data sets composed of DNA sequences of the plastid genome, the multi-copy nuclear ITS region, and the low-copy nuclear phyB gene with a primary focus on the Mediterranean representatives of the complex. As a result, a new lineage, “Drepanensis”, was identified as the seventh entity of the complex. This lineage is endemic to the Mediterranean. The accessions included in the former “Tetraploid” entity were reclassified into two entities: an Asia–Australia–Europe disjunct “Tetraploid_α” with a paternal “Diploid” origin, and a European “Tetraploid_γ” originating from a maternal “Drepanensis” lineage. Another entity, “Tetraploid_β”, is likely to have been originated as a result of chloroplast capture through backcrossing hybridization between paternal “Tetraploid_α” and maternal “Tetraploid_γ”. Additional discovery of multiple tetraploidizations as well as hybridization and chloroplast capture at the tetraploid level indicated that hybridization has been a significant factor in the diversification of Ruppia.     

Components of the major urinary protein complex of inbred mice: Determination of NH2-terminal sequences and comparison with homologous components from wild mice

The major urinary protein (MUP) complex of normal inbred laboratory mice (Mus musculus musculus) is a family of three electrophoretically distinguishable components, designated 1, 2, and 3 in order of increasing anodal mobility at pH 5.5. Components 1 and 2 are under the control of a single genetic locus; the MUP complex of a given inbred strain consists of component 1 or 2 plus component 3. In this study, the urinary protein of two subspecies of Asian wild mice, Mus musculus molossinus (originally trapped in Japan) and Mus musculus castaneus (originally trapped in Thailand), was examined electrophoretically and ultracentrifugally. The MUP complex of male M. m. molossinus and M. m. castaneus sedimented at approximately the same rate as that of M. m. musculus (s ₂₀ =2.0?2.2S). It consisted of a “fast” (i.e., more anodal than component 3) and an “intermediate” component plus one or more “origin” (i.e., less anodal than component 1) components. The “fast” and “origin” components were isolated chromatographically, and NH₂-terminal sequences spanning the first 36 residues were determined. Comparison with the NH₂-terminal sequences determined for components 1, 2, and 3 isolated from the urine of BALB/c or C57BL/6 mice revealed, except for a single replacement at position 6 in the “origin” component of M. m. molossinus, no differences among the 1, 2, “origin”, and “fast” components. Component 3 was highly homologous but differed from component 1 at nine positions; its residue at position 6 was the same as that of the M. m. molossinus “origin” component.     

Primary homologies of the circumorbital bones of snakes

Some snakes have two circumorbital ossifications that in the current literature are usually referred to as the postorbital and supraorbital. We review the arguments that have been proposed to justify this interpretation and provide counter‐arguments that reject those conjectures of primary homology based on the observation of 32 species of lizards and 81 species of snakes (both extant and fossil). We present similarity arguments, both topological and structural, for reinterpretation of the primary homologies of the dorsal and posterior orbital ossifications of snakes. Applying the test of similarity, we conclude that the posterior orbital ossification of snakes is topologically consistent as the homolog of the lacertilian jugal, and that the dorsal orbital ossification present in some snakes (e.g., pythons, Loxocemus, and Calabaria) is the homolog of the lacertilian postfrontal. We therefore propose that the terms postorbital and supraorbital should be abandoned as reference language for the circumorbital bones of snakes, and be replaced with the terms jugal and postfrontal, respectively. The primary homology claim for the snake “postorbital” fails the test of similarity, while the term “supraorbital” is an unnecessary and inaccurate application of the concept of a neomorphic ossification, for an element that passes the test of similarity as a postfrontal. This reinterpretation of the circumorbital bones of snakes is bound to have important repercussions for future phylogenetic analyses and consequently for our understanding of the origin and evolution of snakes. J. Morphol. 274:973–986, 2013. © 2013 Wiley Periodicals, Inc.     

Development and diversity of the suspensorium of trichomycterids and comparison with loricarioids (Teleostei: Siluriformes)

Studies of ontogenetic series of trichomycterids and other catfishes reveal that the suspensorium of siluroids is highly specialized; several synapomorphies separate siluroids from other teleosts. In siluroids, the palatoquadrate is divided into pars autopalatina and pars pterygoquadrata and both are usually connected by the autopaiatine-metapterygoid ligament. The pterygoquadrate is broadly joined to the dorsal limb of the hyoid arch, forming a cartilaginous hyomandibular-symplectic-pterygoquadrate plate in early ontogeny. This produces a special alignment of the hyomandibula and quadrate which is characteristic of siluroids. A symplectic bone is absent. The interhyal is absent in trichomycterids and astroblepids. Dorsal and ventral limbs of the hyoid arch are connected by a ligament. A rudimentary interhyal and this ligament are present in primitive siluroids such as diplomystids and nematogenyids as well as loricariids. The metapterygoid arises as an anterior ossification of the pars pterygoquadrata in siluroids. The formation and position of the metapterygoid exhibit two patterns: (1) the metapterygoid develops as an ossification of a cartilaginous projection positioned between the future hyomandibula and quadrate in primitive catfishes (e.g., Diplomystes) as well as in Nematogenys, callichthyids, loricariids, and astroblepids; (2) the metapterygoid arises as an ossification of the cartilaginous projection (pterygoid process) positioned just above the articular facet of the quadrate for the lower jaw. An ossified anterior chondral pterygoid process of the complex quadrate is present in trichomycterids, whereas the process is absent (simple quadrate) in catfishes such as diplomystids, nematogenyids, callichthyids, and loricariids. The anterior membranous process of the quadrate of Astroblepus is non-homologous with the chondral pterygoid process of trichomycterids; both structures arose independently within the loricarioids. Despite topological relationships, the origin and development of bones reveal the presence of a chondral hyomandibula which develops a large meinbranous outgrowth during ontogeny and a chondral metapterygoid in trichomycterids. The presence of a compound hyomandibula + metapterygoid or a compound metapterygoid + ectopterygoid + entopterygoid have no developmental support in trichomycterines or other siluroids. The “entopterygoid” of Nematogenys and Diplomystes arises as an ossification of a ligament. The dermal entopterygoid of other ostariophysans and the “entopterygoid” are homologous. An ectopterygoid or tendon bone “ectopterygoid” is absent in loricarioids. The suspensorium is an important structural system which has significant evolutionary transformations which characterize loricarioid subgroups; however, no character, of the suspensorium supports the monophyly of the loricarioids.     

The Effect of Dolphin-Assisted Therapy on the Cognitive and Social Development of Children with Down Syndrome

Cognitive and speech development are delayed in children with Down syndrome (DS). We investigated the effect of dolphin-assisted therapy (DAT), a form of animal-assisted intervention, on the development of speech/language and social behavior in children with DS. We hypothesized that DAT would improve the social and cognitive functions with respect to verbalization and thereby promote task performance. A semi-crossover design was used to study 45 children with DS: 18 received a weekly one-hour session of DAT for 6 weeks (group A), 12 children (group B) started with swimming pool sessions (control period of 6 weeks) and thereafter received DAT, and 17 children (group C) were put on a waiting list (control period of 6 weeks) before receiving DAT. The parameters “verbalization,” “impulsiveness,” “proper understanding of rules,” “recognition of persons,” and “establishing contacts” were measured using the Matson Evaluation of Social Skills for Individuals with Severe Retardation (MESSIER) before and after DAT, as well as before and after each of the control periods. Repeated measures ANOVA revealed no significant changes for any of the variables during the control periods (swimming pool, waiting list). Following the period of DAT there was a significant improvement in “verbalization” and “recognition of persons,” while “impulsiveness” decreased. No significant changes were found for the other parameters. “Verbalization” continued to increase during the follow-up period of 6 months, while “recognition of persons” slightly decreased. The results of this study provide support for our hypothesis. Through improvements in verbalization and the recognition of persons, the execution of tasks among children with DS receiving DAT improved. Additional studies are needed to determine if these positive effects of DAT are long-term.     

Fort Union Porcellanite And Fused Glass: Distinctive Lithic Materials Of Coal Burn Origin On The Northern Plains

Abstract

Among the most common surface indicators of archaeological sites in south central Montana and northern Wyoming are the grey and red porcellanite flakes resulting from tool making activities. Although one of the major lithic materials used by prehistoric inhabitants of the northern plains region, porcellanite’s identity has remained relatively unknown. Amateur and professional archaeologist alike have loosely referred to this material as “metamorphosed siltstone”, “baked shale”, “Powder River chert”, “grey chert”, “fired brick”, “jasper”, etc. Similarly, fused glass is often misrepresented as obsidian. Because of its unique origin, definablearea of occurrence (the western coal region, the European coal fields, and perhaps other coalbearing areas), and its extensive utilization by the prehistoric populations of the region, porcellanite and fused glass deserve additional attention from archaeologists.     

"Communalities" in the ossification timing of the growing foot

After investigating communality of ossification timing (mean intercorrelation during growth) for 24 postnatal ossification centers of the foot, it is obvious that some bony nuclei have maximum predictive value and others provide little information about the ossification status of the growing foot. Employing the ten centers of highest communality in both sexes (primarily proximal and metatarsal centers) and excluding the cuboid, lateral cuneiform and low-ranking centers, it is possible to obtain a new center-specific average communality in excess of 0.60. While these high-ranking centers from the basis for a “rational” approach to skeletal assessment, low-ranking and zero-communality centers are of major genetic interest.     

Calcium binding by troponin-C and homologs is correlated with the position and linear density of "beta-turn forming" residues.

The sequences of troponin-C, the light chains of myosin, the parvalbumins and modulator protein are known to contain one to four regions that are homologous with the sequence of the calcium binding region (the “EF-hand” configuration) of the carp parvalbumin of known three dimensional structure. Of the twenty-nine regions examined here, seventeen are known or inferred to bind calcium. Here we describe a correlation between the position and linear density of “β-turn forming” residues in these regions and their ability to bind calcium. The correlation provides a quantitative criterion for evaluating Kretsinger's proposal that “any protein which contains an EF-hand is calcium modulated”.     

Claims and limits of phylogenetic systematics1

Within the methodology of phylogenetic systematics four hierarchic levels are distinguished: the “Central Claim” (to reconstruct phylogeny), methodoloical postulate (to conclude analysis with a purely dichotomous cladogram if ever possible), method (search for sister-group relationships by character analysis), and “Taxonomic Principle” (establishment of a classification reflecting merely the recognized genealoy). Certain limits of applicability and reliability of traditional phylogenetic systematics are specified: genealogy can only be analysed among taxa with perceptible evolutionary novelties; reticulated genealogy is not yet regarded; events other than cladogenetic ones cannot be recognised. Phylogenetic systematics is an independent method which has not been absorbed by any type of “pattern” or “transformed” cladism. Phylogenetic systematics relies on the theory of evolution, which does not lead into circularity, since phylogenetic systematics does not claim to prove or to explain evolution whatsoever.     

Analysis of Wrist Pulse Signal: Emotions and Physical Pain

BackgroundPulse diagnosis (wrist pulse signal) is a well-known traditional technique used for a health examination. It has the potential to detect cardiac and non-cardiac diseases.ObjectiveA study was conducted to investigate human emotions using wrist pulse signal assessment. The aim was to categorize anxiety, boredom, physical pain, and reference state by processing and analysis of acquired signals.MethodA protocol was designed to induce emotions. Data were acquired from 24 healthy volunteers. Signals were processed and further analyzed using paired t-test and Analysis of Variance (ANOVA). Machine learning algorithms, Linear Discriminant Function (LDF), Quadratic Discriminant Function (QDF), and Support Vector Machine using kernel Gaussian radial basis function (RBF-SVM) were used to evaluate significant features and classify the emotions.ResultsComputing significant plus ranked features performed better over randomly selected features for pairwise emotion classification. Here, the QDF classifier outperforms LDF. Additionally, ANOVA validated the effectiveness of statistically prominent features to classify emotional states. Ratio_Pulse_Strength, total_power, Spectral Entropy, and meancd5 came out as the four most significant features to classify the emotion “Anxiety”, “Boredom”, “Pain”, and “Reference” with positive prediction rate of 100%, 73%, 100%, and 86% respectively using RBF-SVM in the user-independent model.ConclusionPreviously, WPS has been used mainly to detect physical abnormality in the human body. The results endorse the potential of user-independent human emotion detection using a wrist pulse signal. The present work was focusing on a few emotional states. Results are encouraging and may be well applied to many more states.     

The effects of stimulus rates upon median,ulnar and radial nerve somatosensory evoked potentials

We examined the effect of stimulus rates on the somatosensory evoked potential (SEP) amplitude following stimulation of the median nerve (MN) and the ulnar nerve (UN) at the elbow or wrist, and the radial nerve (RN) at the wrist in 12 normal subjects. We measured the amplitude of frontal (P14-N18-P22-N30) and parietal peaks (P14-N20-P26-N34) at a stimulus rate of 1.1, 3.5 and 5.7 Hz. The amplitude attenuation was found at frontal P22 and N30 and to a lesser degree at parietal N20 and P26 peaks with an increasing stimulus rate from 1.1 to 5.7 Hz. The amplitude attenuation was greatest at the elbow when compared to the wrist stimulation for both MN and UN. The attenuation was least for wrist stimulation for the RN. The UN block by local anesthesia just distal to the stimulus electrode at the elbow abolished the amplitude attenuation caused by the fast stimulus rate. The observed amplitude attenuation with the faster stimulus rate is probably due, in part, to interference from the “secondary” afferent inputs. The secondary afferent inputs arise from peripheral receptor stimulation (muscle, joint and/or cutaneous) as a subsequent effect of efferent volleys initiated from the point of stimulation. The greater number of peripheral receptors being activated as more proximal sites of stimulation in a mixed nerve would result in greater attenuation of the SEP recorded from scalp electrodes. We postulate that the attenuation of frontal peaks by the fast stimulus rate is due to the frontal projection of interfering “secondary” afferent inputs.     

The ontogenetical and supposed phylogenetical fate of the parietal muscles in the Ctenostomata (Bryozoa)

A new term, “trophon”, has been introduced for the feeding and sexually propagating unit in the stolonate ctenostomes; the “stolon” and the “trophon” represent “sukzooids”, because they are homologous only to parts of the autozooids in the uniserially arranged ctenostomes. – The ontogeny of the muscles, especially the parietal muscles, has been studied in 17 species of ctenostomatous bryozoans belonging to different sub-groups of this order; the main effort was directed toward the details of the differentiations in living animals (14 of the investigated species). In various species of the Ctenostomata two separate sets of parietal muscles develop – probably as a consequence of the elongation of the cystid; the functional parietal muscles in the trophons of the stolonial forms are homologous to the secondary parietal muscles found in several uniserial ctenostomes. Contrary to the supposition by Soule (1954) in the different families of the serially arranged forms the muscles appear in different sequences during the development of the zooid and partly have different ontogenetical fates. Neither the “Carnosa” nor the “Paludicellea” (s. 1.) nor the “Stolonifera” can be maintained as taxa with the argument of a similar ontogeny of the muscles. A detailed comparison regarding the fate of the parietal muscles (and the polypide anlage) showed similarities between certain of the uniserial to either some of the stolonial, the sheet like, or the cystid-fusing forms suggesting a separate evolutionary origin of the advanced forms in those groups of the serially growing forms. – A new family, Pottsiellidae fam. nov., has been introduced and defined.