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Available ecological information, an extensive distributional range, conflicting osteological data, and a proposed early Miocene origin provide the impetus for the present study which investigates genetic structuring, biogeographic, and phylogenetic relationships within the Aplocheilichthys spilauchen lineage. Through the analysis of the mitochondrial gene COI, species delimitation methods (ABGD, GB, GMYC, bPTP) were applied, recognizing 6–7 OTUs with absolute pairwise genetic distances ranging between 8 and 22%. The onset of diversification is estimated to be within the middle Miocene and both dispersal and vicariance-shaped A. spilauchen diversity and distribution, as suggested by time-calibrated and ancestral range reconstruction (S-DIVA) analyses. We report for the first time, a pattern of diversification within a lineage of brackish water fish that is concordant with the historical distribution of coastal mangroves forests, shaped by a series of historical events that likely affected forest cover since the middle Miocene (e.g. major climate shifts and sea-level fluctuations, onset of the modern Congo River outlet, increased volcanism in the Cameroon Volcanic Line). Supplementary information The online version of this article (doi:10.1007/s10750-020-04497-3) contains supplementary material, which is available to authorized users.

Previous research has found that spontaneous synchronization of bodily movements emerges when people interact. This dynamic interactional synchrony occurs in all kinds of everyday movements and has been demonstrated empirically in a variety of social contexts. The objective of this study is to advance our understanding of the dynamical processes that enable the spontaneous and fluid coordination of movements in more naturalistic social interactions. We measured the degree of interactional synchrony of 44 dyads who enacted a series of knock-knock jokes together and we manipulated the perceptual information available (using auditory occlusion) and the individuals' dynamical motor 'signatures' by weighting their limbs. Our analyses using relative phase and fractal/multifractal measures support the conclusion that both local and global dynamical synchronization processes sustain the interactional fluidity seen in conversational exchanges and provide an embodied foundation for how humans connect and cooperate socially.

Even high functioning children with Autism Spectrum Disorder (ASD) exhibit impairments that affect their ability to carry out and maintain effective social interactions in multiple contexts. One aspect of subtle nonverbal communication that might play a role in this impairment is the whole-body motor coordination that naturally arises between people during conversation. The current study aimed to measure the time-dependent, coordinated whole-body movements between children with ASD and a clinician during a conversational exchange using tools of nonlinear dynamics. Given the influence that subtle interpersonal coordination has on social interaction feelings, we expected there to be important associations between the dynamic motor movement measures introduced in the current study and the measures used traditionally to categorize ASD impairment (ADOS-2, joint attention and theory of mind). The study found that children with ASD coordinated their bodily movements with a clinician, that these movements were complex and that the complexity of the children's movements matched that of the clinician's movements. Importantly, the degree of this bodily coordination was related to higher social cognitive ability. This suggests children with ASD are embodying some degree of social competence during conversations. This study demonstrates the importance of further investigating the subtle but important bodily movement coordination that occurs during social interaction in children with ASD.

Two experiments evaluated change in the perception of an environmental property (object length) in each of 3 perceptual modalities (vision, audition, and haptics) when perceivers were provided with the opportunity to experience the same environmental property by means of an additional perceptual modality (e.g., haptics followed by vision, vision followed by audition, or audition followed by haptics). Experiment 1 found that (a) posttest improvements in perceptual consistency occurred in all 3 perceptual modalities, regardless of whether practice included experience in an additional perceptual modality and (b) posttest improvements in perceptual accuracy occurred in haptics and audition but only when practice included experience in an additional perceptual modality. Experiment 2 found that learning curves in each perceptual modality could be accommodated by a single function in which auditory perceptual learning occurred over short time scales, haptic perceptual learning occurred over middle time scales, a...

The current study examined whether the amount and location of available movement information influenced the stability of visuomotor coordination. Participants coordinated a handheld pendulum with an oscillating visual stimulus in an inphase and antiphase manner. The effects of occluding different amounts of phase at different phase locations were examined. Occluding the 0°/180° phase locations (end-points) significantly increased the variability of the visuomotor coordination. The amount of occlusion had little or no affect on the stability of the coordination. We concluded that the end-points of a visual rhythm are privileged and provide access to movement information that ensures stable coordination. The results are discussed with respect to the proposal of Bingham (Ecol Psychol 16:45–43, 2004) and Wilson et al. (Exp Brain Res 165:351–361, 2005) that the relevant information for rhythmic visual coordination is relative direction information.

We describe the application of a nephelometer to in-situ, real-time measurement of the integrated backscattering coefficient σbs of cloud drops. For thin and moderately thick clouds, this quantity is related to the cloud albedo A, for 0° zenith solar radiation, through the relation A=σbsL, where L is the geometric cloud thickness. The instrument was used in a field experiment on El Yunque peak in Puerto Rico. The measured σbs values are in agreement with results of Mie theory calculations, using independently measured cloud drop concentration and size distribution.

An analysis and evaluation of the capability of k–ε low-Reynolds-number turbulence models to predict transition in external boundary-layer flows subject to free-stream turbulence is presented. The similarities between the near-wall cross-stream regions in a fully turbulent boundary layer and the progressive stages through which developing boundary layers pass in the streamwise direction are used to describe the mechanisms by which the models simulate the transition process. Two representative models (Jones and Launder, 1972; Lam and Bremhorst, 1981) are employed in a series of computational tests designed to answer some specific practical questions about the ability of these models to yield accurate, reliable answers over a range of free-stream turbulence conditions.

An approach for improving the prediction of boundary layer transition with k–ε type low-Reynolds-number turbulence models is developed and tested. A modification is proposed that limits the production term in the turbulent kinetic energy equation and is based on a simple stability criterion and correlated to the free-stream turbulence level. The modification becomes inactive in the fully turbulent regime, but is shown to improve both the qualitative and quantitative characteristics of the transition predictions. Although the approach is not limited to a particular low-Reynolds-number model, it is implemented herein using the model of Lam and Bremhorst (1981).

Perception of relative phase and phase variability may play a fundamental role in interlimb coordination. This study was designed to investigate the perception of relative phase and of phase variability and the stability of perception in each case. Observers judged the relative phasing of two circles rhythmically moving on a computer display. The circles moved from side to side, simulating movement in the frontoparallel plane, or increased and decreased in size, simulating movement in depth. Under each viewing condition, participants observed the same displays but were to judge either mean relative phase or phase variability. Phase variability interfered with the mean-relative-phase judgments, in particular when the mean relative phase was 0 degrees. Judgments of phase variability varied as a function of mean relative phase. Furthermore, the stability of the judgments followed an asymmetric inverted U-shaped relation with mean relative phase, as predicted by the Haken-Kelso-Bunz model.

Intra- and interpersonal interlimb coordination of pendulums swung from the wrist was investigated. For both kinds of coordination, the steady state and breakdown of bimanual rhythmic coordination as indexed by the time series of the relative phase angle phi were studied under the manipulation of coordination mode, frequency of oscillation, and the difference in the eigenfrequencies (preferred tempos) of the individual oscillating limbs. The properties observed for both intra- and interpersonal coordination were those predicted by a dynamical model of rhythmic coordination that considers the coordinated limbs coupled to be nonlinear oscillators. Using a regression method, the coupling strengths of the coupled system were recovered. As predicted by the dynamical model, the strength of the dynamic was generally greater for the in-phase than the anti-phase mode and decreased with increasing frequency. Further, the strength of the interpersonal interlimb coupling was weaker than that of intrapersonal interlimb coupling.

OBJECTIVE: Experimental data indicate inhibitory effects of the cerebellum on seizure activity. Structural damage such as cerebellar atrophy, which is a common finding in patients with chronic epilepsy, may reduce these effects. METHODS: Outcome after temporal lobectomy was studied in 78 consecutive patients, with or without cerebellar atrophy diagnosed by MRI. RESULTS: Thirty five patients (45%) showed cerebellar atrophy. At a mean follow up of 14.6 (range, 6-40) months, 50 patients (64%) had no postoperative seizures. In these patients, the frequency of cerebellar atrophy was significantly lower (34%) than in patients who relapsed (64%, p < 0.01). Occurrence of generalised tonic-clonic seizures (GTCS) within two years before surgery, occurrence of GTCS at any time preoperatively, long duration of epilepsy, and older age at surgery were also associated with recurrence of seizures. Multiple logistic regression analysis suggested occurrence of GTCS within two years before surgery and cerebellar atrophy as the main predictive indicators. When both factors were present, the percentage of patients remaining seizure free since surgery fell to 30%, compared with 60% when only GTCS were present, 78.6% when only cerebellar atrophy was present, and 87.5% when both factors were absent. CONCLUSIONS: Cerebellar atrophy shown by MRI was a frequent finding in surgically treated patients with temporal lobe epilepsy. The presence of cerebellar atrophy seems to worsen the prognosis after temporal lobe resection.

The authors investigated event dynamics as a determinant of the perceptual significance of forms of motion. Patch-light displays were recorded for 9 simple events selected to represent rigid-body dynamics, biodynamics, hydrodynamics, and aerodynamics. Observers described events in a free-response task or by circling properties on a list. Cluster analyses performed on descriptor frequencies reflected the dynamics. Observers discriminated hydro- versus aerodynamic events and animate versus inanimate events. The latter result was confirmed by using a forced-choice task. Dynamical models of the events led us to consider energy flows as a determinant of kinematic properties that allowed animacy to be distinguished. Orientation was manipulated in 3 viewing conditions. Descriptions varied with absolute display orientation rather than the relative orientation of display and observer.

The XR1-1 and XR1-2 (Ex-Reactor) experiments, investigating metallic core melt relocation in boiling water reactor (BWR) geometry were performed in August and November of 1993. The XR1 tests represented the BWR control blade and channel box structures in the lower part of the BWR core as metallic core materials are beginning to melt and drain downwards. The purpose of this experiment program is to examine the behavior of downward-draining molten metallic core materials in a severe reactor accident in a dry BWR core, and to determine conditions under which the molten materials drain out of the core region or freeze to form blockages in the lower portion of the core.

Cerebellar atrophy (CA) is a frequent finding in patients with chronic epilepsy. To find out whether the existence of CA has an influence on the tolerance of high-dose monotherapy with carbamazepine, we compared the lowest individual toxic serum levels in patients with complex focal seizures, with CA (n = 27) and without CA (n = 20) in computerized tomography (CT). There was no statistical difference between the groups, even after separating patients with mild CA (n = 20) from those with more severe damage (n = 7). In addition, other clinical, EEG and CT data also seemed to have no influence on the individual toxic threshold serum levels of carbamazepine.

A coordinated rhythmic movement pattern is a dynamical activity involving many hidden layers of rhythmic subtasks. To investigate this dynamical substructure, spectroscopic concepts and methods were applied to an interlimb rhythmic movement task requiring 1:1 frequency locking of two hand-held pendulums in 180 degrees phase relation. The pendulums could be of identical or very different dimensions, thereby providing different values of the ratio omega of uncoupled frequencies. Analyses focused on the power spectrum of continuous relative phase as a function of variation in omega. Predictions were derived from the theories of mode locking and fractal time. Experimental results were in agreement with theoretical expectations and were discussed in terms of the possible recruiting of rhythmic subtasks in the assembling of interlimb absolute coordination, the interdependence of these subtasks, and the general dynamical principles that relate coordinative processes occurring at different length and time scales.

Task dynamics corresponding to rhythmic movements emerge from interactions among dynamical resources composed of the musculature, the link segments, and the nervous and circulatory systems. This article investigated whether perturbations of interlimb coordination might be effect over circulatory and nervous elements. Stiffness of wrist-pendulums oscillated at a common tempo and at 180 degrees relative phase was perturbed through the use of tonic activity about an ankle. Left and right stiffnesses, the common period, and the phase relation all changed. Stiffnesses increased with ankle torque in proportion to the wrist's inertial load. Despite different changes in stiffness at the two wrists, isochrony was preserved. The stability was shown to be consistent with the proportionality of changes in stiffness to the inertial loads. The phase departed from antiphase in proportion to the asymmetry of inertial loads. The size of departures decreased with increasing ankle torque. An account was developed in terms of muscular, circulatory, and nervous functions.

A case of partial aplasia of the right internal carotid artery with an unusual artery passing through the skull base below the hypophysis is described. An association between the presence of this vessel and recurring abnormalities of eye movements with alternating ptosis is assumed. The ontogeny and phylogeny of this collateral artery are discussed.

A total of 37 children, aged between 12 and 18 years and resident in an epileptic colony, were assessed in several ways for the frequency of their epileptic discharging activity and for the extent of underlying brain pathology. In addition, the children were evaluated for their level of performance on various tests of cognitive and visuo-motor functions. The influence on test performance of the discharging activity and of the extent of pathology was then compared, taking other factors such as age at onset of the seizures, duration of the epileptic illness and level of medication into account as far as possible. Only two factors, namely certain indices of dis charging activity and level of medication, were found to have significantly influenced particular aspects of cognitive performance; it was impossible to document an influence of brain pathology statistically.

Der Nachweis ventraler lumbaler Bandscheibenvorfalle gelingt mittels der Diskographie relativ leicht und eindeutig. Ein Krankheitswert und damit eine klinische Bedeutung wurde diesen Veranderungen bisher nur von einzelnen Autoren zuerkannt. Nach den eigenen Erfahrungen mit der Diskographie scheint der ventrale Bandscheibenvorfall jedoch mit einem Schmerzsyndrom korreliert zu sein, das typischerweise neben einem lokalen Kreuzschmerz eine Ausstrahlung uber die Flanken in den Bauchraum und die Genitalregion zeigt.

Cases are selected which are thought to present the summertime problem of whether a cold front will pass Washington, D. C., from the north “tomorrow”. Variables that measure the effective steering direction at 700 mb., the strength of zonal current at 700 mb., and the availability of cold air in Canada are found to be helpful in separating cases of effective frontal passage from other cases. The variables are combined in scatter diagrams to provide a systematic aid to forecasting the passage of the selected cold fronts.

The application of systematic considerations of upper air conditions to the forecasting of precipitation two days in advance for the Washington-Baltimore area in winter is discussed. Forecasts are made by objective treatment of specific meteorological variables from the 850-mb. and 700-mb. levels. The accuracy of this system is discussed and compared with forecasts made by the usual subjective methods. Comparisons show a strong bias in favor of the methods presented. Use of this system during January 1951 is explained in detail and results indicate significant forecast improvement is possible if an endeavor is made to systematically use present knowledge of certain relationships of conditions aloft to future weather.

Immunity to influenza A virus was demonstrated in tracheal organ cultures by parallel titration of challenge virus in replicate cultures prepared from control and virus-inoculated chickens. Five to 10 times more virus was required to infect 50% of cultures from chickens inoculated intranasally and intratracheally with active virus than from control chickens or from chickens with serum antibody induced by intramuscular and intraperitoneal inoculation of inactivated virus. Viral yield from resistant cultures was reduced. Cultures from chickens immunized with either of two antigenically distinct influenza A viruses were resistant to homotypic virus but susceptible to the heterotypic strain. Medium from such cultures contained virus-specific HAI and neutralizing activity. Cultures from some chickens inoculated up to 31 days previously were resistant. The immune state became undetectable between the first and fourth days of culturing. Results suggest that a secretory immunologic system was at least partially responsible for the immunity of the organ cultures.

The importance of x-ray-investigations of skull is demonstrated in ten remarkable examples. Mostly intracerebral calcification follows inflammatory, traumatic, neoplastic or metabolic disease. In spite of the simplification of contrast-investigations which have assumed great importance x-ray-films of skull often permit specific diagnostic assessment and therefore should be done first.

Myelography with the water-soluble, non-ionic contrast medium Amipaque has given rise to decisive advances in the diagnosis of cervical myelopathy. The possibility of discerning excellent detail of anatomical structures in the spinal canal (this applies even for vessels) permits exact visualization of pathological changes. Since the amount and concentration of the contrast medium have a critical influence on side effects, they should be kept as low as possible. This is achieved via the lateral approach at C 1/2 by fractionated administration, and ideal positioning of the patient without tilting. As can be seen from Table 1, the high frequency of examinations in the meantime shows that the diagnostic value of this procedure has been recognized by clinicians.

The non-ionic water-soluble contrast medium Amipaque (metrizamide) shows a lowered neurotoxicity, and therefore it may be used in the entire spinal canal. The better visibility of fine structures compared with oily and gaseous contrast media allows an excellent diagnostic approach to all spinal affections. Our technique of myelography is described and typical examples are given.

Anterior lumbar disc herniations can easily and clearly be evidented by discography. The morbidity and, especially, the clinical importance of this entity, however, has been described by some authors only. According to our own experience with discography, ventral lumbar disc herniation seems to be correlated with a painful syndrome consisting of both a typical and circumscribed backache and pain radiating into the abdominal cavity and genital area along the lateral aspect of the lumbar region.

The myelographic diagnosis of lumbar disc herniations remains unclear in about 5% of the cases. When the clinical examination does not allow clear localisation of the segmental level of the lesion and symptomatology is atypical, discorgraphy may be the only procedure providing further diagnostic information. Very lateral as well as ventral disc herniations can thus be clearly demonstrated. Knowledge of both typical and atypical findings is, however, required to avoid false negative results.

The non-ionic water-soluble contrast medium metrizamide (Amipaque) allows the examination of all regions of the spinal canal. Excellent visualization, the low toxicity for nervous tissue, and small side effects make metrizamide the best contrast medium for myelography, even in infants and children. The technique used is described and results are demonstrated.

Objects for throwing to a maximum distance were selected by hefting objects varying in size and weight. Preferred weights increased with size reproducing size-weight illusion scaling between weight and volume. In maximum distance throws, preferred objects were thrown the farthest. Throwing was related to hefting as a smart perceptual mechanism. Two strategies for conveying high kinetic energy to projectiles were investigated by studying the kinematics of hefting light, preferred, and heavy objects. Changes in tendon lengths occurring when objects of varying size were grasped corresponded to changes in stiffness at the wrist. Hefting with preferred objects produced an invariant phase between the wrist and elbow. This result corresponded to an optimal relation at peak kinetic energy for the hefting. A paradigm for the study of perceptual properties was compared to size-weight illusion methodology.

A case of partial aplasia of the right internal carotid artery with an unusual artery passing through the skull base below the hypophysis is described. An association between the presence of this vessel and recurring abnormalities of eye movements with alternating ptosis is assumed. The ontogeny and phylogeny of this collateral artery are discussed.

Lumbar discography is a good supplement to myelography in the evaluation of low back pain and sciatica. Knowledge of both typical and atypical findings helps to avoid false positive and negative diagnoses. On the other hand atypical findings may show up pathological processes, elsewhere only seen by pathological anatomy. In some cases a relation between these phenomena and clinical symptoms is found.

Six cases of traumatic aneurysms of the extracranial internal carotid artery are presented. It has been an unexcepted finding in all patients without actual clinical importance. Angiography has been repeated in two cases. Possible sequale of these lesions are discussed.