Significant Differences In Direction Research Articles

Experimental investigation on the moisture movement behavior of granites

This study comprehensively investigates the hygric performance of two commonly used types of granite in masonry, each characterized by distinct porosity levels. A series of experimental tests, including capillary absorption, one-dimensional drying, cup methods, vacuum saturation, sorption/desorption isotherms, mercury intrusion porosimetry, and ultrasonic pulse velocity, was conducted in different directions and by using both pure water and NaCl solutions. The results highlight pronounced anisotropy in the granite’s hygric response, with significant directional differences in liquid and vapor moisture movement, as well as ultrasonic wave propagation. Granite with lower porosity and a finer pore structure exhibited hysteresis effects and more pronounced hygroscopic behavior, while granite with higher porosity showed greater capillary activity. The presence of salt crystals within the pore network significantly influences vapor and liquid transport properties, porosity, and moisture storage capacity. The gradual formation of sodium chloride crystals on drying surfaces noticeably altered drying kinetics, influenced by salt concentration and pore characteristics. These findings provide valuable insights into the hygric properties of granite, essential for understanding its durability and informing moisture transfer numerical models.

Study into the Evolution of Spatiotemporal Characteristics and Driving Mechanisms of Production–Living–Ecological Spaces on the Indochina Peninsula

Influenced by historical background, regional economic development, and the frequent occurrence of armed conflict, the human–earth relationship in the Central and Southern Peninsula, which is located in a “fragmented zone”, is characteristic of the region. The Indochina Peninsula has now become an area of interest for the study of spatial changes in production–living–ecological spaces (PLES). Taking the Indochina Peninsula as the study area, this paper explores the evolution of the spatiotemporal patterns of PLES and its driving mechanism in the Indochina Peninsula, from 2010 to 2020, based on a grid scale. Methods such as the land-use transition matrix, land-use dynamics index, and geographically and temporally weighted regression (GTWR) were used in our model, which will provide the basic data and reference for sustainable development planning across the Indochina Peninsula. Our results show that, from 2010 to 2020, ecological space dominated the PLES pattern on the Indochina Peninsula, but its area gradually decreased, accompanied by a sharp increase in the areas of productive and living spaces. The area of PLES interconversion on the Indochina Peninsula in 2010–2020 was 212,818.70 km2, and the intertransfer of production and ecological spaces was distributed in a networklike manner throughout the Indochina Peninsula, while the transfer of living space was distributed in a pointlike manner. The migration path of the center of gravity of PLES on the Indochina Peninsula demonstrated a significant directional difference, and the direction and extent of the standard deviation ellipse distribution of the ecological space was similar to that of the production space. The PLES’s pattern evolution was affected by the degree of multiple factors, with a significant spatial and temporal heterogeneity. The positive and negative feedback effects of the factors were distributed in different areas and in different transfer directions.

Moving reference point goalposts and implications for fisheries sustainability

AbstractFor many environmental indicators, the sustainable status can change because of changes in either the monitored state or the policy goal. Fisheries provide an intensively monitored setting to investigate the relative impacts of such change. Key fisheries sustainability indicators comprise the ratio between fishing pressure or biomass and their respective reference levels. We developed a retrospective database of population status, reference point changes and reported reasons for changes for all data‐rich stocks in the ICES region. We derived methods to distinguish the impacts of either source of change (monitored state or policy goal) on sustainable status. We found that reference points changed frequently (64% of populations had reference point changes) with varying magnitudes. Contrary to expectation, reference point changes were often not compensated by changes in the state thus significantly impacting inferred sustainability status and dependent scientific advice. Across a range of life histories and assessments, changes in reference points dominate retrospective revisions in status over the full time series. Overall, status before and after the change of reference point had no significant directional differences that would suggest reference point change effecting movement towards or away from sustainability. Although multiple factors have contributed to reference point changes, our results show that the reference point definition and the technical basis for estimation were the most important reasons for change. Recognizing that reference points are not constant in time but rather form reference series is paramount to quantifying present and historical sustainability. Properly documenting, justifying and quantifying the impacts of such change is an ongoing challenge.

Dimensional Accuracy Evaluation of Temporary Dental Restorations with Different 3D Printing Systems.

With the advent of 3D printing technologies in dentistry, the optimization of printing conditions has been of great interest, so this study analyzed the accuracy of 3D-printed temporary restorations of different sizes produced by digital light processing (DLP) and liquid crystal display (LCD) printers. Temporary restorations of 2-unit, 3-unit, 5-unit, 6-unit, and full-arch cases were designed and printed from a DLP printer using NextDent C&B or an LCD printer using Mazic D Temp (n = 10 each). The restorations were scanned, and each restoration standard tessellation language (STL) file was superimposed on the reference STL file, by the alignment functions, to evaluate the trueness through whole/point deviation. In the whole-deviation analysis, the root-mean-square (RMS) values were significantly higher in the 6-unit and full-arch cases for the DLP printer and in the 5-unit, 6-unit, and full-arch cases for the LCD printer. The significant difference between DLP and LCD printers was found in the 5-unit and full-arch cases, where the DLP printer exhibited lower RMS values. Color mapping demonstrated less shrinkage in the DLP printer. In the point deviation analysis, a significant difference in direction was exhibited in all the restorations from the DLP printer but only in some cases from the LCD printer. Within the limitations of this study, 3D printing was most accurate with less deviation and shrinkage when a DLP printer was used for short-unit restorations.

Comparative analysis of Russian and industrialized countries performance on Energy and Fuels, WoS, 2008–2017

The selection of basic research priorities plays an important role in efficient science policy. After the economic crisis in 2008 many countries turned its attention to R&D of energy resources. Effective development of R&D could contribute to efficiency of oil and gas processing and improve Russian prosperity. The goal of our study is to examine trends in Russian research performance (RP) and compare them with other leading industrialized countries. More detailed analysis was focused on tracing evolution in the research area (by WoS classification) as Energy&Fuel (E&F), which is invaluable for the Russian economy. Sources of data were Science Citation Index-Expanded (SCI-E) that is the part of Web of Science (WoS), analytical tool InCites and the national database Russian Science Citation Index—Clarivate. World dataset demonstrated the growth rate in total research performance (RP) by 140% (2,006,082 records) in 2017 compared to 2008 (1,416,233 records). Russian RP growth rate was the same as in world dataset in 2008–2017. Our analysis revealed that two of each RA Science Technology and Other Topics, and Energy & Fuels (E&F) demonstrated striking growth rate (in three-fold) comparing with growth rate 140% in the world dataset during 2008–2017. Total amount of Russian RP on E&F consisted of 4237 records indexed in SCI-E and 6300 records indexed in RSCI-C for 10 years. During the last 10 years, Russia significantly improved various citations indicators of RP on E&F. The share of publications in top 1% and top 10% journals increased. Russian RP growth rate on E&F was about 200%. Despite the growth its impact is low compared to leading industrial countries. A significant disparity was revealed in RP distribution by leading organizations in SCI-E and RSCI-C. Powerful Russian oil and gas companies are practically absent among organizations indexed in SCI-E. Contrarily, the national Russian database RSCI-C revealed a network of regional branches of the famous private oil company named “Lukoil”. Russian international collaboration (IC) on E&F is significantly less (about 8–10%) than in total Russian RP. The negative factor is low number of IC on E&F with each of traditional Russian partners as Germany and USA. Value of Jaccard index of almost all countries collaborating with Russia (besides Kazakhstan’s 0.46) is no higher than 0.2. This indicates significant difference in direction of research. Our data could be useful as a source for effective decision-making.

Three‐dimensional laparoscopic vision improves forceps motion more in the depth direction than in the horizontal direction: An analysis of data from prospective randomized controlled trials

Three-dimensional (3D) laparoscopic vision can improve depth perception. However, it is a question whether 3D vision can improve motion in the depth direction. The aim of this study was to compare the impact of 3D vision on forceps motion in the depth and horizontal directions. All data were obtained from our previous two studies, where, in total, 40 novices and 20 moderately experienced surgeons participated. A simple phantom task was performed in a training box. The participants were randomly assigned to two groups. Specifically, one group performed the task five times initially under a two-dimensional (2D) system, and the other group started under a 3D system. Both groups then performed the same task five times under the alternative system. Performances were recorded by an optical position tracker. We separately evaluated forceps motion in the x-, y-, and z-axis directions. Compared with the findings for 2D vision, the forceps path lengths were significantly decreased among novices and moderately experienced surgeons in almost all tasks under 3D vision. In a comparison of the path length ratio (3D/2D) in each direction, larger reduction was observed for the depth direction among novices, whereas no significant directional difference was noted among moderately experienced surgeons. For novices, 3D laparoscopic vision improves depth perception and may give shorter forceps movement in the depth direction even for simple tasks.

Directional Skid Resistance Characteristics of Road Pavement: Implications for Friction Measurements by British Pendulum Tester and Dynamic Friction Tester

The British pendulum tester (BPT) and the dynamic friction tester (DFT) are commonly used to evaluate the polishing effect of traffic on pavement skid resistance. The present study was conducted to answer two questions: (i) whether the directional moving traffic action results in significant directional differences in skid resistance of the pavement, and (ii) if so, whether BPT and DFT are effective tools for evaluating the skid resistance performance of polished pavements with significant directional skid resistance characteristics. Five in-service pavement sections with different degrees of polishing were examined in this study. The following findings were obtained from the study: (a) There were statistically significant differences between the longitudinal and transverse skid resistance of the polished pavements tested; (b) there were no statistically significant differences between the longitudinal and transverse skid resistance of the newly paved unpolished pavement tested; (c) BPT was able to differentiate the directional skid resistance differences of the polished pavements tested; and (d) DFT was unable to differentiate the directional skid resistance differences of the polished pavements tested. DFT produces one skid resistance value for a circular path at each test point. The test results found that DFT over-estimated the traffic-direction skid resistance of in-service pavements. The over-estimation errors ranged from 0.001 to 0.023 DFT units, and the corresponding percent errors were from 0.4% to 11.1%. This finding suggests that the over-estimation effect of skid resistance directionality of polished pavements on DFT measurements should be recognized in pavement skid resistance evaluation and pavement safety studies.

Sleeping position of shelter dogs

There has been considerable interest in canine laterality. Some dogs will hold a toy or take their first step consistently using a right paw, whereas others will use their left paw. Some species also show laterality of lying position. We investigated the postures assumed by 12 dogs living in a shelter. The dogs spent 492 ± 116.4 min/night lying in lateral recumbency curled clockwise and 807.4 ± 129 min/night lying in lateral recumbency curled counterclockwise. Nine of the 12 dogs spent the majority of their recumbent time curled counterclockwise, but there was no significant difference in direction (P < 0.054). Laterality, although observed in many aspects of canine behavior, does not seem to extend to sleeping posture in this species.

Directions of Colour Changes of Nectar Honeys Depending on Honey Type and Storage Conditions

Abstract The colour of honey is one of the most important quality criteria for consumers. The colour depends mainly on the content of plant pigments but the honey consistency, shape, and size of the crystals may also influence the honey colour parameters. It is related to the crystallisation and decrystallisation processes of honey during storage. In the present study, directions of colour changes of honey during storage were evaluated using a tristimulus colorimeter and the CIE 1976 L*a*b* and CIE L*C*ho systems. The effect of time (3 and 9 months) and storage conditions (cold storage, room temperature storage with access to light, and room temperature storage without access to light) on the colour of nectar honeys was investigated. The results obtained showed that both the type of honey and the storage conditions influenced the honey colour parameters. Significant differences in direction and intensity of the colour changes of honey during storage were observed. These differences make it difficult to indicate which storage conditions are optimal to preserve the colour of the honey. It was found that acacia and heather honeys were the most susceptible to colour changes during long-term storage in all of the study’s applied conditions, whereas rape and buckwheat honeys were the most stable in colour parameters.

Directional spectra of hurricane-generated waves in the Gulf of Mexico

[1] Hurricane-induced directional wave spectra in the Gulf of Mexico are investigated based on the measurements collected at 12 buoys during 7 hurricane events in recent years. Focusing on hurricane-generated wave spectra, we only consider the wave measurements at the buoys within eight times the radius of the hurricane maximum wind speed (Rmax) from the hurricane center. A series of numerical experiments using a third-generation spectral wave prediction model were carried out to gain insight into the mechanism controlling the directional and frequency distributions of hurricane wave energy. It is found that hurricane wave spectra are almost swell-dominated except for the right-rear quadrant of a hurricane with respect to the forward direction, where the local strong winds control the spectra. Despite the complexity of a hurricane wind field, most of the spectra are mono-modal, similar to those under fetch-limited, unidirectional winds. However, bi-modal spectra were also found in both measurements and model results. Four types of bi-modal spectra have been observed. Type I happens far away (>6 × Rmax) from a hurricane. Type II is bi-modal in frequency with significant differences in direction. It happens in the two left quadrants when the direction of hurricane winds deviates considerably from the swell direction. Type III is bi-modal in frequency in almost the same wave direction with two close peaks. It occurs when the energy of locally-generated wind-sea is only partially transferred to the swell energy by non-linear wave-wave interactions. Type IV was observed in shallow waters owing to coastal effects.

Single-trial event-related potentials and the orienting reflex to monaural tones

We aimed to clarify the event-related potentials (ERPs) involved in elicitation and habituation of the orienting reflex (OR), seeking parallels with two autonomic measures reflecting different stages in OR-related processing. Participants were presented with 8 unexpected innocuous novel tones to one ear at long variable inter-stimulus intervals, and horizontal eye movement in the direction of the ear of stimulation was taken as a behavioural measure of the OR. Skin conductance, heart rate, and 19 EEG channels were also recorded. Single-trial ERPs were decomposed using principal components analysis for intervals covering the early N1 complex and the late positive complex (LPC). Eye movements at trial 1 showed significant directional differences with ear of stimulation, and this difference reduced over trials, providing behavioural evidence of OR elicitation and habituation. Electrodermal responses, Processing Negativity, and the Novelty P3 showed substantial main effects of trials, suggesting their close links to the OR. Cardiac deceleration and Component 1 of the N1 complex showed no change over trials, suggesting their association in marking the transient onset of each stimulus. Component 3 of the N1 complex, P3a, P3b, and early and late Slow Waves showed only topographic changes over trials, and their dominant continuation over the stimulus sequence rules them out as OR markers. Theory development is required to clarify the non-OR role of the LPC. These results point to the usefulness of a sequential-processing approach to the OR in accommodating the range of subcomponents in the ERP. These data also illustrate the value of single-trial ERP analysis in simple paradigms with very long inter-stimulus intervals.

Comparative study of vertebral fractures and luxations in dogs and cats

The purpose of this retrospective study was to compare patterns of vertebral fractures and luxations in 42 cats and 47 dogs, and to evaluate the impact of species-related differences on clinical outcome. Data regarding aetiology, neurological status, radiographic appearance and follow-up were compared between the groups. The thoracolumbar (Th3-L3) area was the most commonly affected location in both cats (49%) and dogs (58%). No lesions were observed in the cervical vertebral segments in cats, and none of the cats showed any signs of a Schiff-Sherrington syndrome. Vertebral luxations were significantly more frequent in dogs (20%) than in cats (6%), whereas combined fracture-luxations occurred significantly more often in cats (65%) than in dogs (37%). Caudal vertebral segment displacement was mostly dorsal in cats and ventral in dogs, with a significant difference in direction between cats and large dogs. The clinical outcome did not differ significantly between the two populations, and was poor in most cases (cats: 61%; dogs: 56%). The degree of dislocation and axis deviation were both significantly associated with a worse outcome in dogs, but not in cats. Although several differences in vertebral fractures and luxation patterns exist between cats and dogs, these generally do not seem to affect outcome.

Brain structure and function related to cognitive reserve variables in normal aging, mild cognitive impairment and Alzheimer's disease

Cognitive reserve (CR) is the brain's capacity to cope with cerebral damage to minimize clinical manifestations. The ‘passive model’ considers head or brain measures as anatomical substrates of CR, whereas the ‘active model’ emphasizes the use of brain networks effectively. Sixteen healthy subjects, 12 amnestic mild cognitive impairment (MCI) and 16 cases with mild Alzheimer's disease (AD) were included to investigate the relationships between proxies of CR and cerebral measures considered in the ‘passive’ and ‘active’ models. CR proxies were inferred premorbid IQ (WAIS Vocabulary test), ‘education–occupation’, a questionnaire of intellectual and social activities and a composite CR measure. MRI-derived whole-brain volumes and brain activity by functional MRI during a visual encoding task were obtained. Among healthy elders, higher CR was related to larger brains and reduced activity during cognitive processing, suggesting more effective use of cerebral networks. In contrast, higher CR was associated with reduced brain volumes in MCI and AD and increased brain function in the latter, indicating more advanced neuropathology but that active compensatory mechanisms are still at work in higher CR patients. The right superior temporal gyrus (BA 22) and the left superior parietal lobe (BA 7) showed greatest significant differences in direction of slope with CR and activation between controls and AD cases. Finally, a regression analysis revealed that fMRI patterns were more closely related to CR proxies than brain volumes. Overall, inverse relationships for healthy and pathological aging groups emerged between brain structure and function and CR variables.

Evidence of effects of human disturbance on alert response in Père David's deer (Elaphurus davidianus)

To understand effects of human disturbance on alert response of Père David's deer, we carried out an experiment in the Dafeng Père David's Deer Reserve (32 degrees 59'-33 degrees 03'N, 120 degrees 47'-120 degrees 53'E), China. In the spring and summer, we observed alert responses (including stare, walking away, and flee) of deer and recorded the intensity of tourist disturbance in a small display pen using a laser-range finder to measure the alert distance of a free-ranging group in a large enclosure. We also recorded the pattern of head orientation when deer were resting in these two deer groups. After statistical analysis, we found that: 1) in small pen, the frequency of alert response was significantly different among different intensities of human disturbance; strong disturbance resulted in higher frequency of alert response; 2) stare distance in the free-ranging group in summer was significantly longer than that in spring, but the distance of walking away and the distance of flee showed no significant difference between the two seasons; and 3) in free-ranging group, there was no significant directional difference in head orientation, whereas in display group, there was a significant directional difference in head orientation. We suggest that: 1) under the captive situation, human disturbance may be one of the factors that affect alert response in Père David's deer; and 2) Père David's deer adopted different alert response to adapt to human disturbance under different circumstance. We recommended that relationships between alert response and human disturbance should be considered in ex situ conservation of this field extinct deer. Zoo Biol 26:461-470, 2007. (c) 2007 Wiley-Liss, Inc.

Novel microsatellites from the green swordtail (Xiphophorus hellerii) also display polymorphism in guppy (Poecilia reticulata)

AbstractThe green swordtail (Xiphophorus hellerii; Poeciliidae) is a popular ornamental freshwater fish species. Fourteen microsatellites were isolated from a green swordtail genomic library enriched for CA‐repeats. Thirteen microsatellites were polymorphic in green swordtail; interestingly four of them were tetranucleotide‐type. Cross‐species amplification showed that 10 of the 14 microsatellites were polymorphic in guppy (Poecilia reticulata; Poeciliidae) as well. No significant directional difference of allele length was seen between the two species at any of the loci tested.

SIGNIFICANT ROLE FOR HISTORICAL EFFECTS IN THE EVOLUTION OF REPRODUCTIVE ISOLATION: EVIDENCE FROM PATTERNS OF INTROGRESSION BETWEEN THE CYPRINID FISHES, LUXILUS CORNUTUS AND LUXILUS CHRYSOCEPHALUS.

Samples of Luxilus cornutus, Luxilus chrysocephalus, and their hybrids were collected along hypothesized routes of dispersal from Pleistocene refugia to examine the significance of geographic variation in patterns of introgression between these species. Patterns of allozyme and mitochondrial DNA (mtDNA) variation were generally consistent with those from previous studies. Tests of Hardy-Weinberg equilibrium revealed significant deficiencies of heterozygotes in all samples, indicating some form of reproductive isolation. Mitochondrial DNAs of each species were not equally represented in F1 hybrids; however, this bias was eliminated when the two largest samples were excluded from the analysis. Backcross hybrids exhibited biased mtDNA introgression, as samples from Lake Erie (eastern) and Lake Michigan (western) drainages showed significant excesses of mtDNAs from L. chrysocephalus and L. cornutus, respectively, relative to frequencies of diagnostic allozyme markers. The extent and direction of allozyme and mtDNA introgression was quantified by calculating isolation index values from morphologically "pure" individuals of each species from each locality. Analysis of variance of these measures identified limited introgression of allozyme variants with no geographic pattern, but significant differences in direction of mtDNA introgression between drainages (i.e., postglacial dispersal route). Association between patterns of mtDNA introgression and dispersal route across the latitudinal width of the contact zone is best explained by genetic divergence during past isolation of ancestral populations from these drainages. These results identify a significant role for historical effects in the evolution of reproductive isolation and the process of speciation.

Doppler and echocardiographic characteristics of patients having an Austin Flint murmur.

The purpose of this study was to investigate the genesis of the Austin Flint murmur using Doppler and echocardiographic imaging. A total of 51 patients having significant aortic insufficiency and an anatomically normal mitral valve were evaluated. They were divided into two groups; 30 patients had an audible Austin Flint murmur (AFM+) and 21 did not (AFM-). All patients had a complete M-mode, two-dimensional, and Doppler echocardiographic examination to characterize left ventricular size and function, motion of the mitral valve, transmitral flow velocities, direction of the aortic insufficiency jet, and severity of aortic insufficiency. There was no significant difference in severity of aortic insufficiency between groups. There was, however, a significant difference in direction of the insufficiency jet. In the AFM+ group compared with the AFM- group, for the parasternal long-axis view 24 (80%) versus eight (38%) had their insufficiency jet directed at the mitral valve, for the apical five-chamber view the values were 25 (83%) versus five (24%), and for the apical long-axis view the values were 27 (90%) versus five (24%); for all comparisons p less than 0.01. There was also a greater frequency of localized anterior mitral leaflet distortion by two-dimensional echocardiography (AFM+:23 [77%] versus AFM-:five [24%]; p less than 0.001) and a greater frequency of Doppler striations overlying the aortic insufficiency jet (AFM+:25 [83%] versus AFM-:seven [33%]; p less than 0.001). Regarding transmitral flow velocities, there was no significant difference in filling patterns or absolute velocities during early or late diastole between groups. There was no gradient by Doppler analysis or by hemodynamics (n = 26) across the mitral valve in either group. There also was no difference in the frequency of preclosure of the mitral valve (AFM+:two versus AFM-:three). Systolic function was similar in both groups, but the left ventricular end-diastolic dimension was significantly greater in the AFM+ group (6.8 +/- 0.8 cm) than in the AFM- group (6.2 +/- 0.7 cm, p = 0.008). The results of this study suggest that the primary factor responsible for the Austin Flint murmur is the presence of an aortic insufficiency jet directed at the anterior mitral leaflet. This, combined with the biphasic pattern of transmitral flow, distorts the shape of the anterior mitral leaflet as it opens and closes during diastole, making it shudder. The leaflet's shuddering sets up vibrations and shock waves that distort the aortic insufficiency jet, causing the observed Doppler striations and probably the sound of the murmur. There is no evidence from this study to support prior theories that have proposed functional mitral stenosis or diastolic mitral regurgitation as the source of the murmur.

Devising sampling methods for inventory of receptive seed cones of jack pine

Open-grown jack pine (Pinusbanksiana Lamb.) in northern Ontario, ranging in age from 9–20 years, bore an average of 311 receptive seed cones, with the greatest number in the upper midcrown. Generally, counts of receptive seed cones varied more among trees than among directions; most of the variation among trees occurred in the mid to upper crown. The expression F(H) = Hb+1[b + 2 − (b + 1)H], with b = 3.12 (P &lt; 0.001, R2 = 0.94), described the cumulative proportion of receptive seed cones occurring up to relative crown height, H. Significant directional differences in the parameter estimates for b showed that the open-grown jack pines initiated seed cones at slightly lower heights on the south side than on the other sides. For monitoring the crop, a procedure for randomly selecting receptive seed cones with respect to their vertical distribution in the crown was developed. The construction of simple, cost-effective sampling plans for estimating yields of receptive seed cones in jack pine seed orchards is explained. This involves determining the cost of conducting the sampling necessary to achieve a desired precision of estimation. It also involves determining the precision attainable with limited resources to conduct the sampling. With this focus, simple random sampling and two types of stratified random sampling were compared. Stratified random sampling based on relative crown height with equal stratum widths was cost-effective and should be relatively easy to implement operationally.

Rotation of the Italian peninsula from aeromagnetic evidence

Abstract Palaeomagnetic data have been used extensively in order to study the geodynamical history of a region. Similar information can be obtained by analysing the shape of aeromagnetic anomalies and the direction of the total magnetization vector of the anomaly sources. We can suppose that the direction of the Earth's magnetic induction vector is almost constant with time along a N-S direction. If a significant directional difference between total magnetization and induction vector is observed, we can argue that the anomaly sources were affected by conspicuous rotational movements. In the central Southern Tyrrhenian area, the anomaly shape is generally normal i.e., N-S, except for several anomalies which have a maximum-minimum direction parallel to the Italian coast, that is, NW-SE rather than N-S. This feature, and the location of these anomalies on the border of the bathyal plain, seems to be in agreement with the anticlockwise rotation movements suggested in some geodynamical models of the region.

Lateral saccadic latencies and handedness

Lateral saccadic latencies were determined in 18 right-handers and 18 left-handers. Within the right-handed group the mean latency was significantly shorter when looking from the left to the right (242.7 msec) than from right to left (265.0 msec), whereas no significant directional difference was found in the left-handed group. An age effect was also found with longer latencies being associated with increased age. These findings agree with those of Pirozzolo and Rayner ( Neuropsychologia 18, 225–229, 1980) and provide further evidence of the pervasiveness of functional asymmetry in the human brain. The present findings suggest that motoric or central integrative mechanisms may contribute more to saccadic directional asymmetries than do perceptual differences.