Counterclockwise Sense Research Articles

Circular dichroism and exciton effect of syndiotactic methacrylic polymers with chiral diacyl hydrazide side chains—IV. Poly(methacrylic [formula omitted] hydrazide)

The circular dichroism (CD) spectra of syndiotactic methacrylic polymers with histidine-containing diacyl hydrazide side chains show the presence of ordered conformations by exciton effects. Syndiotactic poly(methacrylic acid hydrazide) has been reacted with N- tert.-butyloxycarbonyl- l-histidine to yield poly(methacrylic acid-N β(N (tert.-butyloxycarbonyl) l-histidyl) hydrazide) . In a second polymer-analogous reaction, the protecting N-tert.-butyloxycarbonyl group was removed and the CD and u.v. spectra of both polymers studied in aqueous solution at various pHs. At alkaline pH, the diacylhydrazide group is deprotonated and the CD spectra show exciton doublets which arise by an ordered conformation of the polymer. At higher pH, the positive exciton effect is invariant with time, indicating a clockwise spiralization of the side chains; a time dependence arises in the range of pH = 12–13. The positive exciton effect turns within a longer period of time into a negative exciton effect, with a corresponding reversal to a counterclockwise sense of spiralization in the spatial arrangement of the side chains.

Tectonic rotations on the leading edge of South America: The Bolivian orocline revisited

Cretaceous paleomagnetic poles for South America form three distinct groups, one each for the Andes north and south of Arica (northernmost Chile) and one for the craton. Relative to the cratonal group, the northern Andean group is displaced in a counterclockwise sense and the southern Andean group in a clockwise sense. These data have been used to support a model of orodinal bending of the Andes, but distributed shear caused by oblique subduction is a more likely mechanism.

Neogene tectonic rotation of the San Gabriel Region, California, suggested by paleomagnetic vectors

Previous paleomagnetic work in the western Transverse Ranges and the islands offshore of California has suggested that these regions have experienced large clockwise rotations since middle Miocene time. This study is aimed at testing how far east these rotations extend into the continent. Neogene volcanic rocks from the region bounded by the San Gabriel and San Andreas faults were selected for paleomagnetic study. The sampled units are lavas from the late Oligocene to early Miocene continental Vasquez Formation, and water‐laid tuff beds from the middle to late Miocene Mint Canyon Formation. These rocks possess a stable remanent magnetization which was acquired soon after deposition and is believed to be primary. Seventy‐four lava flows from eleven locations in the Vasquez Formation were studied. The average direction for seven locations near the center of the study area suggests that this area has rotated a net clockwise amount of 37.1°±12.2° since the early Miocene. There is no suggestion of north or south translation. A location west of the central region is rotated almost 90° clockwise, although this is believed to be a local effect. Detailed magnetic stratigraphy at the western and central location can be correlated over 6 km. Locations in the east near the San Andreas fault yielded highly dispersed directions which cannot now be interpreted in terms of rotation. The mean paleomagnetic direction from six sites (four different beds) in the Mint Canyon formation west of the Vasquez study area is deflected in a counterclockwise sense by 16°±30°. These data are consistent with a proposed model in which the San Gabriel region first was rotated clockwise 53° (37° + 16°) in the early Miocene and later rotated 16° counterclockwise as it slid northward into the leftward bend region of the San Andreas fault. The clockwise rotation is believed to be due to dextral shear within the Pacific‐North American plate shear zone; counterclockwise rotation in the Mojave region is believed to be responsible for the bend in the San Andreas fault.

Caulobacter crescentus flagellar filament has a right-handed helical form

Caulobacter crescentus flagellar filaments were examined for their shape and handedness. Contour length, wavelength and height of the helical filaments were 1.34 ± 0.14 μm, 1.08 ± 0.05 μm and 0.27 ± 0.04 μm, respectively. Together with the value of the filament diameter, 14 ± 1.5 nm, the parameters of the curvature (α) and twist (φ) were calculated as 3.9 (%) for α and 0.026 (rad) for φ, which are similar to those of the curly I filament of Salmonella typhimurium. Dark-field light microscopic analysis revealed that the C. crescentus wild-type filament possesses a right-handed helical form. Given the result that C. crescentus cells normally swim forward, in the opposite direction to a polar flagellum, it is likely that C. crescentus swims by rotation of a right-handed curly shaped flagellum in a clockwise sense, whereas S. typhimurium and Escherichia coli swim by rotation of left-handed normal type flagella in a counterclockwise sense.

Rotation of the Peruvian Block from palaeomagnetic studies of the Central Andes

Palaeomagnetic studies were performed on the rocks of the Central Andes to test the hypothesis of oroclinal bending of the Andes around the Peru–Chile border. Natural remanent magnetization of Mesozoic volcanic and sedimentary rocks of Peru shows a counterclockwise shift of declination by several tens of degrees relative to the field directions of the same ages in the stable South American craton. Two Mesozoic dyke swarms from Arica region (northernmost Chile) also indicate about 20° of declination shift in a counterclockwise sense. These results suggest a considerable amount of counterclockwise rotation of large area north of Arica, that is, oroclinal bending of the Andes around some hinge near the Peru–Chile border. One Neogene dyke swarm sampled in central Peru also gave declination which deviates counterclockwisely by ∼15°. If this declination shift is a result of the wide-area tectonic rotation as suggested by the Mesozoic rocks, oroclinal bending appears to have continued until relatively recent times.

Two-dimensional analysis of shape-fabric using projections of digitized lines in a plane

A method of two-dimensional shape-fabric analysis is presented which is based on the projection of lines or ellipses on the x-axis. If a set of lines or ellipses displays a preferred orientation, the average length of projection of the lines or ellipses on the x-axis changes with direction in the x-y plane. The proposed method involves use of Fortran programs which evaluate the average length of projection of lines (e.g., outlines of ooides, pressure solution seams) while the fabric is rotated by small increments in a counterclockwise sense about the origin of the x - y plane. Data acquisition is by digitizing the lines on an enlarged photograph. The sets of x-y coordinates that are thus obtained serve as input for the programs. The basic equations of the method are explained and application to a sedimentary fabric is demonstrated. The proposed method is both fast and sensitive. It is especially useful if the particle outlines are closely spherical or if the fabric is only weakly developed. Yet, the method is not restricted to weak fabrics only. Also, if the fabric is due to deformation this method yields the axes of the two-dimensional strain ellipse.

On the Relative Motion of Binary Tropical Cyclones

The interaction between spatially proximate (binary) tropical cyclones is such that relative rotation in the counterclockwise sense and decreasing separation distance between the two storm centers can be expected. This is referred to as the Fujiwhara effect. This study analyzes this effect for 43 binary tropical cyclone systems which occurred over the western North Pacific, 1949–78. It is shown that most demonstrated mutual interaction according to Fujiwhara expectations. However, there were notable apparent exceptions. Further analysis of these exceptional cases shows that environmental currents in which the storms were embedded had a significant effect on relative motion and masked the Fujiwhara effect. Additionally, it was found that storms exhibiting behavior most in accordance with Fujiwhara expectations were located in or near the Intertropical Convergence Zone. The main conclusion of the study, in confirmation of earlier studies, is that forces relative to environmental steering must be determined and filtered before one can determine forces attributable to the Fujiwhara effect alone.

Low-Frequency Current Regimes over the Bering Sea Shelf

Using direct current measurements made during the period 1975–81, we describe the general circulation over the southeastern Bering Sea and differentiate it by regimes related to depth and forcing mechanisms. Three regimes are present, delineated by water depth (z): the coastal (z ≤ 50 m), the middle shelf (50 < z < 100 m), and the outer shelf (z ≥ 100 m). These are nearly coincident with previously described hydrographic domains. Statistically significant mean flow (∼1 to 10 cm s−1) exists over the outer shelf, generally directed toward the northwest, but with a cross-isobath component. Flow of similar magnitude (1–6 cm s−1) occurs in the coastal regime, paralleling the 50 m isobath in a counterclockwise sense around the shelf. Mean flow in the middle shelf is insignificant. Kinetic energy at frequencies < 0.5 cycle per day (cpd) is greater over the outer shelf than in the other two regimes, suggesting that oceanic forcing is important there but does not affect the remainder of the shelf. Kinetic energy in the band from 0.5 to 0.1 cpd follows a similar spatial pattern, reflecting the greater number of storms over the outer shelf. Mean flow paralleling the 100 and 50 m isobaths appears to be related to a combination of barocline pressure gradients (associated with frontal systems which separate the regimes) and interactions of tideal currents with bottom slopes located beneath the fronts. Although winds are energetic and they result in higher values of kinetic energy during winter, their highly variable behavior suggests that they are not a primary driving force for mean flow.

Dynamics and Community Structure of Zooplankton in the Davis Strait and Northern Labrador Sea

The dynamics and community structure of zooplankton in the Davis Strait and the northern Labrador Sea were studied over an annual cycle (23 April 1977 - 16 May 1978). Biological spring, defined as the time of year which includes the annual phytoplankton increase and subsequent increases in zooplankton abundance, proceeds in a counterclockwise sense around the region. It is first observed in April near the southern Greenland coast, from where it proceeds north in the Davis Strait, then moves southward in the Baffin Current and along the retreating ice edge before reaching the Hudson Strait in September and October. Recurrent group analysis was used to identify communities of zooplankton in the region. Distributions of these groups were closely related to the hydrography. The West Greenland Drift is characterized by abundant populations of Calanus finmarchicus , C. hyperboreus , Oithona similis , Conchoecia obtusata , Metridia longa and Microcalanus pygmaeus. The colder, less saline water of the Baffin Current and the Hudson Strait arctic outflow are characterized by populations of Calanus glacialis and the early developmental stages of Pseudocalanus minutus. The breeding cycles of the three species of Calanus tend to be separated both spatially and temporally. Key words: Davis Strait, Labrador Sea, Zooplankton, Zoogeography, arctic, recurrent group analysis, Calanus

Paleomagnetism of the Devonian Kennett Limestone and the rotation of the eastern Klamath Mountains, California

The Devonian Kennett Limestone in the Eastern Klamath terrane in northern California has a stable magnetization that was acquired after the folding of the formation apparently in the very early Cretaceous. The mean paleomagnetic vector has the direction I = −49°, D = 219°, A95 = 7.2° and the parameters of the corresponding paleomagnetic pole are latitude = 57°, longitude = 332°, A95 = 7.4°. All of the stably magnetized specimens have a single polarity. We propose that the magnetization be associated with the emplacement of the Shasta Bally batholith during the M17 reversed interval at 134 Ma. The firmest conclusion that can be drawn from these data is that the Eastern Klamath terrane has undergone 70 ± 11° of clockwise rotation, since the Early Cretaceous. This result does not support earlier tectonic models in which either the entire Klamaths or terranes on the south side of the Klamaths rotated in a counterclockwise sense. The close agreement between the amount of clockwise rotation and that observed in the Oregon Coast Range to the north of the Klamaths suggests that both may reflect the same tectonic process. The data may suggest a few hundred kilometers of northwestward translation of the terrane since the Early Cretaceous.

A study of the bottom boundary layer over the Eastward Scarp of the Bermuda Rise

Velocity and temperature measurements from the bottom boundary layer (BBL) over the Eastward Scarp of the Bermuda Rise in water depth of 4620 m show little variability over an 8‐month period. The free‐stream flow 62 m above the bottom was south‐southeasterly following the isobaths in the region with an average speed of 22 cm/s. The current vector in the BBL rotated an average of 5° in a counterclockwise sense between 62 and 0.8 m above the bottom. The thickness of the BBL was ∼40 m and the average magnitude of the bottom stress was ∼0.7 dynes/cm2. Mean speed profiles, height of the BBL, and the magnitude of the bottom stress predicted by a model compare favorably with the observations, but the model predicts a rotation of the current vector between 62 and 0.8 m more than twice that measured. The time‐dependent nature of the flow field is also reproduced by the model. The Bermuda Rise data and speed profile measurements at the base of the Scotian Rise show that the M2 clockwise polarized tide is damped more than the mean current as the bottom is approached in the BBL. This phenomenon is reproduced by the model and can be explained by differing effective Ekman layer thicknesses associated with tidal and steady components of the flow.

Paleomagnetism of the Triassic Hound Island Volcanics, Alexander Terrane, southeastern Alaska

The Hound Island Volcanics, a Late Triassic sequence of submarine basalts, has been investigated to determine possible large‐scale movements of crust in southeastern Alaska. Data from oriented cores at 12 sites bordering Keku Strait yielded a mean paleomagnetic pole at latitude 23.0°N, longitude 188.8°E (α95 = 11.0°). Reliability of the pole is affirmed by a fold test and by the consistent antipolarity of normal and reversed magnetic directions. The anomalous position of this pole compared to that derived from coeval paleomagnetic data in central North America indicates that the region surrounding Keku Strait was rotated approximately 100° in a counterclockwise sense. The paleolatitude determined from the basalts is not significantly different from that predicted by data from the craton. Therefore the apparent northward drift of the Alexander terrane indicated by Paleozoic paleomagnetic results occurred before Late Triassic time.

Spiral clouds on Mars: A new atmospheric phenomenon

Viking Orbiter images obtained during the 1978 northern summer on Mars show unusual spiral cloud patterns at high northern latitudes. Well‐developed spirals occurred only during early summer at a time when the sublimation of the annual CO2 frost cap in the north had ceased. The systems ranged in size from 200 to 500 km and all spirals were wound in a counterclockwise sense. An explanation is proposed, based on the radiatively driven instability described by Gierasch, Ingersoll, and Williams. The model predicts disturbances with the correct scale and lifetime. However, the successful development of the spirals depends on the existence of weak mean winds, suggesting that these instabilities can only develop at special null points in the general circulation. We argue that such special circumstances are most likely to occur during early northern summer and are less likely to obtain at a comparable season in the southern hemisphere.

Structural deformation of the Idaho-Wyoming overthrust belt (U.S.A.), as determined by Triassic paleomagnetism

A paleomagnetic study of Triassic redbeds from fourteen sites within the Idaho-Wyoming overthrust belt and three sites from the adjacent stable foreland was undertaken in an attempt to decipher the origin of the arcuate shape of the thrust-fold belt in north-western Wyoming. This belt rises from beneath the Snake River lava plain in eastern Idaho and trends east-southeast into Wyoming. South of Jackson, Wyoming, the belt swings 45 to 70 degrees to trend almost due south into west-central Wyoming. A total of 193 samples were paleomagnetically analyzed using spinner and cryogenic magnetometers. Thermal demagnetization up to 681° C reveals that the natural remanent magnetization consists characteristically of two directional components. A small secondary (chemical) magnetization is revealed at temperatures below 500° C, whereas a proportionally large characteristic magnetization appears to be primary and conforms to the expected Triassic latitudes of the North American craton. The site-mean directions have Fisher precision k ranging from 14 to 149, with confidence cones of 95%-probability ranging between 4.8° and 16.2°. The characteristic (primary) directions of magnetization indicate that the structural bend in the overthrust belt originated through tectonic rotations of the thrust sheets in the horizontal plane, as the paleomagnetic declinations show a systematic change corresponding to the structural configuration mentioned above. We propose that as overthrusting progressed from west to east in the Late Mesozoic and Early Tertiary, the thrust sheets experienced an increasing resistance to movement due to the proximity of the ancient arcuate foreland margin. The buttressing effect of the foreland hinge on the overthrust plates caused the frontal edges of the thrusts to assume the configuration of the foreland margin resulting in horizontal rotations of the thrust sheets. The easternmost Prospect—Cliff Creek—Jackson thrust sheet came into actual contact with the ancestral Teton—Gros Ventre Precambrian block on the north and the Game Hill reverse fault on the east; as a result the northern sections of the thrust sheet rotated by an amount of up to 60 degrees in a counter-clockwise sense and the southern and eastern sections rotated in a clockwise direction by an amount of up to 30 degrees.

Stress fields in central portions of the Pacific Plate: Delineated in time by linear volcanic chains

Many linear island chains in the Pacific appear to consist of individual volcanic shields that lie on relatively short, curved loci sometimes of sigmoidal form. These loci, in turn, lie at an angle to the directions of propagation of the chains. Those chains that now trend just south of east (the Pratt-Welker, Hawaiian, Tuamotu, and Austral chains) consist of en echelon sets of loci with right lateral (clockwise) sense of stepwise overlap, whereas the supposed older extensions of these chains that lie nearly north-south (the Emperor and Ellice-Gilbert-Marshall chains) consist of sets of loci with left lateral (counterclockwise) sense of stepwise overlap. Rift zones of isolated volcanoes in the chains, that is, those volcanoes whose local stress fields were not influenced by the buttressing effects of near-neighbor volcanoes at the time of their formation, show the same orientation as the loci. First-motion studies of earthquakes in the Pacific lithosphere to date are few in number and give a variety of solutions with inferred directions of maximum principal compression (P) nearly horizontal and trending in both northeasterly-southwesterly and northwesterly-southeasterly directions. However, the number of such solutions is small, in some cases related to edifice effects, and interpretations relating compression and dilatation to principal stress directions in magmatic source regions are open to question. We consider it likely that the dominant orientation patterns have been due to dynamic effects related to the overall kinematic patterns of Pacific plate motions. Although a large number of different factors can influence the inherent and transmitted stresses in the lithosphere, and thereby influence the locally dominant stress field, we conclude that the effective stress orientations in the very recent past and for about the last 40–50 m.y. can be considered to have been caused by dynamic forces reflected in a right lateral rotational couple acting within the plane of the Pacific plate. These forces have induced maximum (S1) principal compressional stress directions that have had surface traces trending about northwest-southeast, relating to minimum (S3) principal stress directions that have trended northeast-southwest. Prior to 40–50 m.y. ago the dominant stress orientations in the plate were caused by a tendency for left lateral stress rotations, which induced maximum (S1) principal compressional stress directions with surface traces that trended just west of north and minimum (S3) principal stress directions that trended just north of east. These data and interpretations are independent of whether or not a change in direction of motion of the Pacific lithospheric plate took place roughly at the time represented by the bends in the island chains and are also independent of arguments as to whether melting anomalies of the Pacific are rigidly fixed or whether they are better explained in terms of thermal plumes or gravitational anchors. We conclude that the trends and age correlations of volcanic loci in the Pacific accurately track and identify the evolution of states of stress in the Pacific lithosphere with time. As more age data for linear island edifices become available, it should be possible to construct a Pacific-wide chronology of volcanism independent of but similar to that developed from magnetic reversals. Further, it appears that changes in stress directions in the plate have been episodic and that they may correlate with episodic magma generation not only in the central part of the Pacific plate but also around its margins.

Permian paleomagnetic result from the Western Pyrenees delineating the plate boundary between the Iberian Peninsula and stable Europe

The natural remanent magnetizations of Permian basaltic flows and Permian (?) dikes of the massifs of Cinco-Villas and La Rhune in the western Pyrenees have been studied. An unfolding test proves the characteristic magnetizations of the flows to be prefolding. From mainly thermal demagnetization analyses, a mean direction of magnetization has been calculated: D = 217.5°, I = −11.3°, k = 25°, and α95, = 7° for N = 17 sites (65 samples) and a virtual pole position at 40°N, 126°E. The characteristic directions of magnetization in the samples from the two dikes are conformable with those from the Permian flows. The paleodeclination of this result does not deviate in a counterclockwise sense from those from stable Europe, and it is concluded that this part of the Pyrenees was not rotated with the Iberian Peninsula. We have further delineated the fossil plate boundary between the Iberian Peninsula and stable Europe. The hypothesis of the evolution of the Bay of Biscay in two or more distinct stages is supported: the initial stage or stages imply a counterclockwise rotation of the Iberian Peninsula in Late Jurassic-Cretaceous times; later, a compressional Early Tertiary stage occurred during which the Iberian Peninsula moved northward with respect to stable Europe, thereby creating the Pyrenean orogen and its western continuation in the southern margin of the Bay of Biscay.

Equatorial Acceleration and Continental Paths: ABSTRACT

A mantle weak enough for convection is also weak enough to End_Page 1902------------------------------ show zonal effects due to the earth's rotation. Zonal rotation--or equatorial acceleration--in a plastic mantle, underneath rigid crustal blocks, should have certain specific results. For instance, major continental blocks in the Northern Hemisphere should, over the long term, describe counterclockwise loops. North America has had such a path, as has Europe. Present motions along the rim of the Pacific Ocean suggest that the North Pacific plate also has been following a counterclockwise loop. Major continental blocks in the Southern Hemisphere should describe clockwise loops. This has been the pattern for Antarctica, Australia, and South America. Africa, located primarily in the Southern Hemisphere during Paleozoic time, traced a clockwise loop during that era; in Cenozoic time, largely in the Northern Hemisphere, it has been moving with counterclockwise curvature. Further, major blocks close to the equator should have a greater west-to-east acceleration than major blocks located far from the equator. Hence, South America should be moving eastward relative to North America, and Africa should be moving eastward relative to Europe, North America, and South America. The northward paths of Europe and North America, relative to Africa and South America, also indicate major tensional effects in the Mediterranean and Gulf of Mexico-Caribbean areas. The Northern Pacific block should be moving eastward faster than the North American block as it is closer to the equator, and should be turning in a counterclockwise sense. This movement provides a north-south zone of east-west compression along the western edge of North America and down the East Pacific Rise. Reconstruction of block paths indicates that Gondwanaland, a hypothetical Paleozoic supercontinent, was more likely a convergence of individual blocks which had separate previous histories. End_of_Article - Last_Page 1903------------

Theoretical Approach to History of Southern United States: ABSTRACT

The hierarchical plate hypothesis of geologic history includes the concept that the North American continental block has been circling the Pacific Basin plate in a counterclockwise sense and rotating in the same sense, with an approximate period of 109 years. Implications inherent in the hypothesis, for comparison with the actual history of North America during its latest 109 years of development, include the following. 1. Climate: Continental glaciation about 109 years ago; warming during late Precambrian. Tropical during Paleozoic; much carbonate deposition; widespread coal in late Paleozoic. Cooling during Mesozoic and Cenozoic, climaxing in new glaciation. 2. Appalachian Mountains: Left lateral movement plus compression during Paleozoic. Right lateral movement plus tension during Mesozoic and Cenozoic. 3. Carribbean: Developed initially about end of Paleozoic--beginning of Mesozoic. Strike-slip margins on north and south. 4. Gulf of Mexico: Tensional feature; developed initially about end of Paleozoic-beginning of Mesozoic. 5. Sedimentation: Major drainage toward south (ambient coordinates), producing very large sediment volumes in Gulf of Mexico. 6. Depocenter: Shifting location toward north and east, from Texas into Louisiana, due to continental rotation during post-Paleozoic. 7. Stream patterns: Reorientation, due to continental rotation, through Mesozoic and Cenozoic in clockwise sense for first-order drainage, counter-clockwise for second-order drainage in mid-continent area; much piracy. 8. Eastern and western margins: Lateral shrinking subsidence, and formation of north-south grabens, during post-Paleozoic. 9. Diapirism: Dikes, plugs, volcanoes, and salt domes (where salt was available) along western, southern, and eastern margins, during Mesozoic and Cenozoic. 10. Probable geosyncline: Short-lived, late Paleozoic age; near southern edge of continent; orientation now northeast-southwest. These predictions compare favorably with the actual history of the continent. End_of_Article - Last_Page 1700------------

The anterior subdivision block of the left bundle branch of his: II. Experimental vectorcardiographic observations

The diagnostic criterion for the vectorcardiographic recognition of left anterior subdivision block (LASB) is based upon the following points:o1.The total duration of the curve increases from 20 to 36 msec.2.The spacial location of the curve is to the left, upwards and backwards.3.The VCGF in the vertical anatomical position of the heart shows an 8-shaped configuration. The initial portion is rotated clockwise, oriented to the left and downwards; its intermediate and final segments rotate in a counterclockwise manner in a direction to the left and upwards. In the horizontal plane, the loop is also directed in a counterclockwise sense and to the left, but backward; in most instances a curled portion is observed at its vertex. A terminal slurred segment is distinct in both planes.4.The VCGF in the horizontal anatomical position of the heart shows the same duration increment; it is rotated counterclockwise with a direction upwards and to the left, but its terminal slurred segment is shifted to the right of the “Y” axis. The general behavior of the VCGH is similar to that observed in the vertically placed hearts. The differences reside in the angulated initial segment and its terminal portion oriented to the right. .The total duration of the curve increases from 20 to 36 msec. The spacial location of the curve is to the left, upwards and backwards. The VCGF in the vertical anatomical position of the heart shows an 8-shaped configuration. The initial portion is rotated clockwise, oriented to the left and downwards; its intermediate and final segments rotate in a counterclockwise manner in a direction to the left and upwards. In the horizontal plane, the loop is also directed in a counterclockwise sense and to the left, but backward; in most instances a curled portion is observed at its vertex. A terminal slurred segment is distinct in both planes. The VCGF in the horizontal anatomical position of the heart shows the same duration increment; it is rotated counterclockwise with a direction upwards and to the left, but its terminal slurred segment is shifted to the right of the “Y” axis. The general behavior of the VCGH is similar to that observed in the vertically placed hearts. The differences reside in the angulated initial segment and its terminal portion oriented to the right. The association of LASB with right bundle branch block (RBBB) gives rise to the following vectorcardiographic patterns: The general appearance of the curve is the one usually seen in RBBB, but its initial segment, as well as the R loop (those portions of the VCGH oriented to the left of the “Z” axis) maintains the characteristics pertaining to isolated LASB. These are: slurrings at the centrifugal limb of the R loop and the counterclockwise rotation in both planes; a curled, clockwise-rotated portion at the vertex of the RH, in the majority of the cases, with a forward direction in the horizontal anatomical position, and to the back when in the vertical one.

On the Polarization Characteristics of middle latitude Geomagnetic Micropulsations

Geomagnetic micropulsations of different types are observed on the Soviet stations in the middle latitudes of the Northern hemisphere, Behaviour of the 'horizontal disturbed vector is analysed.&#x0D; &#x0D; Micropulsations of Pc2-4 and Pi2 types are shown to have statistically dominant counter-clockwise sense of rotation in the morning hours but clockwise sense of rotation in the evening hours. Both the rotational character of polarization and the diurnal variation of the sense of rotation suggest the Alfven (transverse) hydromagnetic thanks to mode is an important part of the micropulsation mechanism, although it is difficult to explain the micopulsation occurrence in middle and low latitudes Ignoring the magneto-acoustic (longitudinal) mode of propagation.&#x0D; &#x0D; All the micropulsation types appear to have the preferred directions characteristic of the observational point Diurnal variation of the hourly mean directions are similar at different sites and appear to have the largest departure progress of from the mean around the morning and the evening hours. Directional properties of micropulsations can be explained by the lateral in-homogeneities in the sub-surface geo-electrical structure.