Migration Front Research Articles

Distributional Patterns and Seasonal Movements of Procellariiformes in the North Pacific.

Pelagic seabird surveys were made during 11 trans-pacific round navigations of car-transport ships between Japan and U. S. A., March 1983-February 1985. In a total of 124 recorded seabird species (5 Orders, 14 Families), the Procellariiformes included: Diomedeidae 2, Procellariidae 29 and Hydrobatidae 10 species. Their distribution showed the following patterns: 1. Boreal to temperate dispersal pattern 2. Temperate to subtropical dispersal pattern 3. Coastal patterns (Japanese and U. S. west coasts) 4. Subtropical endemic pattern 5. Subtropical to northward dispersal pattern. These distributional patterns reflected the specific adaptive levels to water temperature. The seasonal advance and retreat of migratory front could be traced in some trans-equatorial southern hemisphere species, and the main migratory lane was suggested in the Hawaiian leeward waters. In a few related species pairs, mutual shifts of main distributional sea areas were noticed.

Molecular Forms of Serum Insulin-Like Growth Factor (IGF)-Binding Proteins in Man: Relationships with Growth Hormone and IGFs and Physiological Significance*

Insulin-like growth factor-I (IGF-I) and IGF-II are associated in the blood with specific binding proteins (BPs), forming complexes that elute in gel filtration with estimated mol wt around 40 and 150 kD. The latter appears to be under GH control. Five molecular forms of BP (41.5, 38.5, 34, 30, and 24 kD) have been identified by Western blotting using 125I-labeled IGF. All five forms are present in the smaller complexes, but only the 41.5- and 38.5-kD forms are found in the larger complexes. In this study immunoblotting showed that the 41.5- and 38.5-kD forms were recognized by antibodies directed against the GH-dependent BP purified from human plasma, and the 30-kD form was recognized by antibodies directed against the BP purified from amniotic fluid. The 34- and 24-kD forms proved to be immunologically unrelated to the other three. In sera with large quantities of the 41.5- and 38.5-kD forms, an additional band was often observed immediately ahead of the migration front of the 30 kD band. This was recognized by the anti-GH-dependent BP antibody and probably corresponds to a degradation product of the 41.5- and 38.5-kD BPs. Serum 41.5- and 38.5-kD BPs have been found to be elevated in acromegaly, where GH hypersecretion causes increased IGF-I levels, and diminished in cases of genetic or idiopathic GH deficiency and defects of the GH receptor (Laron's syndrome), where both IGF-I and IGF-II are decreased, as well as in Pygmy adults and children who have isolated IGF-I deficiency. In all of these conditions, the proportions of the 34- and 30-kD forms were inversely related to those of the 41.5- and 38.5-forms. Under treatment, the BP profiles tended to return to normal. In cases of GH deficiency caused by a tumor, the BP profiles resembled those of hypopituitary or normal serum, depending on whether IGF levels were diminished or normal. It, therefore, seems that BP synthesis is coordinated with IGF-I synthesis and may not be directly GH dependent. The results of neutral pH gel filtration analysis of hypopituitary (idiopathic and tumoral) and normal sera point to a relationship between the levels of circulating IGFs and those of the 150-kD IGF-BP complex whose binding units are the 41.5- and 38.5-kD BPs. It, therefore, seems that the 150-kD complex controls the bioavailability of IGF-I and IGF-II.(ABSTRACT TRUNCATED AT 400 WORDS)

Production of low molecular weight chemoattractants for leukocytes by periovulatory ovine follicles.

Studies were performed to determine if periovulatory ovine follicles secrete chemoattractants for leukocytes, and if so, to begin to elucidate the chemical nature of such factors. Tissues were obtained at 0, 12, 24, and 36 h after initiation of the preovulatory surge of luteinizing hormone and placed in short-term incubation (ovulation occurs at approximately 24 h). Follicular-conditioned medium was tested for its ability to attract leukocytes by utilizing a linear under-agarose assay: chemotaxis was quantified as a function of the leading front of migration of cells. Neutrophils and eosinophils were attracted toward media conditioned with tissues of 24 and 36 h. Monocytes responded toward medium of tissues collected at 36 h. There was no evidence for chemoattraction of basophils or lymphocytes. Chemoattractant activity for granulocytes and monocytes was of low molecular weight origin (less than 3000) and water-soluble. High-performance liquid chromatographic separation of this sample produced a distinct peak with recoverable activity. The isolated fraction was rich in glycine. Eosinophils also migrated toward an additional low molecular weight attractant that was extracted into ethyl acetate. Leukocytes attracted into periovulatory follicles might produce substances (eg., proteolytic enzymes and angiogenic factors) that play a role in the mechanisms of ovulation and luteinization.

Age differences in the timing and biometrics of migrating Marsh Warblers in Kenya

Kelsey, M. G., Backhurst, G. C. & Pearson, D. J. 1989. Age differences in the timing and biometrics of migrating Marsh Warblers in Kenya. Ring. & Migr. 10: 41–47. Marsh Warblers Acrocephalus palustris migrate southwards across East Africa during November and December on a narrow migration front. Night-time trapping of migrants attracted to powerful game-viewing lamps at Ngulia Safari Lodge in Tsavo West National Park in southeast Kenya provides a unique opportunity to study numbers of active migrants in Africa. Marsh Warblers are one of the most numerous species caught. Biometric data spanning twelve years were analysed. The passage of Marsh Warblers became increasingly dominated by first-autumn birds as the season progressed. Differences in weight between individuals appeared to be largely accounted for by differences in fat reserves rather than by wing-length (as a measure of body size). Wing-lengths decreased through the season whereas body weight and fat reserves showed no seasonal change. There was n...

Apolipoprotein distribution in human lipoproteins separated by polyacrylamide gradient gel electrophoresis.

The heterogeneity of serum lipoproteins (excluding very low density (VLDL) and intermediate density (IDL) lipoproteins) and that of lipoproteins secreted by HepG2 cells has been studied by immunoblot analysis of the apolipoprotein composition of the particles separated by polyacrylamide gradient gel electrophoresis (GGE) under nondenaturing conditions. The reactions of antibodies to apoA-I, apoA-II, apoE, apoB, apoD, and apoA-IV have revealed discrete bands of particles which differ widely in size and apolipoprotein composition. GGE of native serum lipoproteins demonstrated that apoA-II is present in lipoproteins of limited size heterogeneity (apparent molecular mass 345,000 to 305,000) and that apoB is present in low density lipoproteins (LDL) and absent from all smaller or denser lipoproteins. In contrast, serum apoA-I, E, D, and A-IV are present in very heterogeneous particles. Serum apoA-I is present mainly in particles of 305 to 130 kDa where it is associated with apoA-II, and in decreasing order of immunoreactivity in particles of 130-90 kDa, 56 kDa, 815-345 kDa, and finally within the size range of LDL, all regions where there is little detectable apoA-II. Serum apoE is present in three defined fractions, one within the size range of LDL, one containing heterogeneous particles between 640 and 345 kDa, and one defined fraction at 96 kDa. Serum apoD is also present in three defined fractions, one comigrating with LDL, one containing heterogeneous particles between 390 and 150 kDa, and one band on the migration front. Most of serum apoA-IV is contained in a band comigrating with albumin. GGE of centrifugally prepared LDL shows the presence of apoB, apoE, and apoD, but not that of apoA-I. However, the particles containing apoA-I, which, in serum, migrated within the LDL size range and as bands of 815 to 345 kDa, were recovered upon centrifugation in the d greater than 1.21 g/ml fraction. GGE of high density lipoproteins (HDL) indicated that most of apoA-I, A-II, and A-IV were present in lipoproteins of the same apparent molecular mass (390-152 kDa). ApoD tended to be associated with large HDL, and this was also significant for HDL apoE, which is present in lipoproteins ranging from 640 to 275 kDa. GGE of very high density lipoproteins (VHDL) presented some striking features, one of which was the occurrence of apolipoproteins in very discrete bands of different molecular mass. ApoA-II was bimodally distributed at 250-175 kDa and 175-136 kDa, the latter fraction also containing apoA-I.(ABSTRACT TRUNCATED AT 400 WORDS)

Migration of seismic activity along intraplate seismic belts in the Japanese Islands

Migration of seismic activity after eight large earthquakes which occurred in and near Japan is investigated. It is found that migration velocities are in most cases in the range between several km/yr and 100 km/yr. However, in some cases, seismic activity in the regions more than a few hundred kilometers distant from the focal regions of great earthquakes are induced just after the earthquake occurrence. In these cases, apparent migration velocities are more than 100 km/day, although large earthquakes above M 6 seldom or never occur. In almost all cases, seismic activity migrates along intraplate seismotectonic belts containing the focal region of the large earthquakes which have triggered the migrational activity. It is interesting to note, in relation to the prediction of large intraplate earthquakes, that the activity of small earthquakes of about M 4 are sometimes observed in the whole of the seismic belts, in a relatively short period preceding the commencement of migration of larger earthquakes in those belts. When a gap remains behind the migration front, it is likely to be filled later. A “seismic gap” concept seems to be most effectively applicable to these gaps as far as intraplate seismic activity is concerned. Although the physical mechanism of migration has not been found as yet, the phenomena are sometimes useful for forecasting future large earthquakes, and help us to understand intraplate seismotectonics.

Inhibition of human neutrophil chemotaxis by the protein kinase inhibitor, 1-(5-isoquinolinesulfonyl) piperazine.

The protein kinase inhibitor, 1-(5-isoquinolinesulfonyl) piperazine (C-I), inhibits superoxide release from human neutrophils (PMN) stimulated with phorbol myristate acetate or synthetic diacylglycerol, without inhibiting superoxide release from PMN stimulated with the chemoattractants C5a or N-formyl-methionyl-leucyl-phenylalanine (f-Met-Leu-Phe). In this study, we investigated the effect of C-I on human PMN chemotaxis to C5a, f-Met-Leu-Phe, leukotriene B4 (LTB4), and fluoresceinated N-formyl-methionyl-leucyl-phenylalanine-lysine (f-Met-Leu-Phe-Lys-FITC). PMN, preincubated for 5 min at 37 degrees C with 0 to 200 microM C-I, were tested for their migratory responses to the chemoattractants. C-I (greater than or equal to 1 microM) significantly inhibited PMN chemotaxis to f-Met-Leu-Phe, f-Met-Leu-Phe-Lys-FITC, and C5a without affecting random migration. Maximal inhibition of chemotaxis to these attractants occurred with greater than or equal to 50 microM C-I, at which chemotaxis was inhibited by 80 to 95%. The C-I inhibition was reversible. In contrast, 200 microM C-I did not inhibit the number of PMN migrating to LTB4, although, the leading front of PMN migration to LTB4 was inhibited by C-I. C-I inhibited PMN orientation to C5a and f-Met-Leu-Phe without affecting orientation to LTB4. C-I did not inhibit the binding of radiolabeled f-Met-Leu-Phe or f-Met-Leu-Phe-Lys-FITC to PMN. These findings suggest that the chemotactic responses of PMN to f-Met-Leu-Phe and C5a involve a protein kinase-dependent reaction which is inhibited by C-I.

Analysis of polarization and orientation of human polymorphonuclear leukocytes by computer-interfaced video microscopy.

Chemotactic behavior is a complex cellular response to chemical environmental stimuli. For polymorphonuclear leukocytes (PMNs), such behavior involves net migration as well as changes in cell shape and cell orientation. Accordingly, we have applied computer-interfaced video microscopy to analyze cell shape and orientation in control and patient PMNs migrating under agarose. From a digitized tracing of the PMNs at the leading front of migration, cells were characterized in terms of area, circumference, and longest dimension. A shape factor and angle of orientation were computed. Numerical shape factors discriminated three PMN morphologies: polar, apolar, and hyperpolar. Only polar cells could be oriented. Orientation of polar cells was defined as toward, away, or disoriented with respect to the chemotactic gradient. Apolar cells were considered to be nonoriented. Of PMNs from healthy controls, 30 +/- 5% of the cells were oriented toward and 11 +/- 4% of the cells were oriented away from the gradient. For PMNs from patients with localized juvenile periodontitis, a 40% deficit in net migration was associated with reduced orientation toward (5 +/- 2%) and elevated orientation away from the gradient (33 +/- 9%). PMNs from a panel of patients with thermal injury showed reduced migration and orientation toward the gradient associated with elevated percentages of apolar cells. Such analysis of PMN polarization and orientation of the leading front permitted calculation of a chemotactic behavior index. Application of this multiparameter index to the analysis of the chemotactic response may identify PMNs that are defective, but not by evaluation of any single variable.

Processes dominating forced-flow thin-layer chromatography

The effect of the vapor phase and other special influences on thin-layer chromatography have been investigated. Comparisons were made of the relationships of time vs. developing distance and flow rate vs. efficiency using a planar arrangement of the thin-layer. Covering the layer facilitates the reproducibility and of the migration front but the most effective optimization step for thin-layer chromatography is provided by forced-flow of the mobile phase. It is suggested that planar chromatography with a covered sorbent layer and using a pressurised solvent stream should be calledforced-flow thin-layer chromtatography.

Atomic diffusion coefficients calculated for transition metals in olivine

Atomic diffusion in minerals is one of the most important processes for obtaining information on the formation and subsequent cooling histories of minerals or recks. We have estimated the atomic diffusion coefficients of four transition metals in the forsterite structure on the basis of the potential energy map using the Born–Mayer type repulsive energy term in the WMIN program1,2. The cation was assumed to migrate along the minimum energy pass of the map. We have estimated the activation energies for the M1 cation migration front the height of the saddle point at the pass, and the frequency terms for diffusion from the shape of the energy minimum around the M1 site. Our calculated values are in line with experimental results3. Although the diffusion phenomena give us information about the genesis and cooling histories of the minerals, the atomic diffusion coefficients in geologically important minerals such as pyroxene are often too low to measure experimentally; we show here how our theoretical approach may be applied to such minerals.

Wound repair of the oral mucosa

The migratory and proliferative capacity of oral epithelium was studied after induction of subepithelial suction blisters in palatal rat mucosa. FITC-coupled lectins and their affinities to epithelial cells at the wound margin were analyzed by immunofluorescence microscopy. Immunocytochemical distribution of 67 K-keratin polypeptides in different epithelial layers were studied using specific antisera against keratin proteins. By means of 3H-thymidine-autoradiography the proliferation of epithelial basal cells and their migration at the wound edge was quantified by evaluation of the labelling index. Double labelling was performed, combining the autoradiographic and the keratin staining technique. It was found that the subepithelial suction blister showed rapid repair (epithelial regeneration after 3-4 days). Peanut Agglutinin (PNA) showed a selective affinity to the basal 2-3 layers of oral rat mucosa. No modifications of lectin affinities were found in epithelial wound repair. PNA-positive keratinocytes were demonstrated in the migratory epithelial tongue. The selective presence of 67 K-keratin (67 K) in the suprabasal epithelial cell layers was interpreted as an indication of the differentiation process in rat oral mucosa. The 3H-thymidine-labelling index of basal cells increased significantly, beginning at the wound edge after 24 h. The peak of the labelling index curve was located in the vicinity of the wound after 96 h. Double labelling technique revealed 67 K-negative and 3H-thymidine-positive basal cells as well as 67 K-positive and 3H-thymidine-negative cells at the migration front. These observations support findings that migrating epithelial cells in oral wound healing derive both from undifferentiated (str. basale) and from differentiated (inferior str. spinosum) cell compartments.

Submarine Cementation Patterns of Holocene Reefs Provide Models for Porosity Development in Ancient Reef Reservoirs: ABSTRACT

An understanding of processes of formation and postdepositional alteration of Holocene carbonate buildups can aid the explorationist in locating and predicting reservoir facies in subsurface analogs. In the subsurface, ancient shelf-edge reefs may contain primary porosity that has escaped shallow subsurface cementation. This preserved primary porosity is commonly enhanced later by carbonate dissolution associated with widespread subsurface fluid migration and/or dissolution fronts along permeable stylolite zones. Therefore, given a burial history of continued subsidence, knowledge of early submarine cementation patterns is important for understanding reef facies distribution of late subsurface diagenesis. In reef systems, submarine cementation is controlled by size of sedimentary components, facies energy setting, and reef growth history. Cements are acicular aragonite and dentate Mg-calcite rims, and more commonly thin crusts and geopetal skeletal infills of Mg-calcite peloids. Rapid facies accumulation during reef growth limits submarine cementation to thin rims and incomplete skeletal infilling. Extensive back-reef sediment apron deposits are generally mud free and composed of well-sorted skeletal fragments, that undergo only minor submarine cementation. Reef core (framework) facies contain large amount of in-situ skeletons and increasing mud and peloidal submarine cements within the core matrix. High energy fore-reef facies are extensively cemented by fibrous aragonite druses and d nse peloidal Mg-calcite infill. The best potential reservoir facies are usually back-reef packstone-grainstones, which have greater porosity and permeability because high accumulation rates and moderate energy conditions limited submarine cementation. Following a reef's demise and submergence, submarine cementation of the upper reef surface may form an effective diagenetic End_Page 502------------------------------ seal over the reef that protects internal reef components from additional submarine diagenesis. Consequently, some primary porosity remains intact, that, with continued submergence, may bypass meteoric diagenesis and still remains to become enhanced by late subsurface events. Within core samples of Cretaceous and Miocene reefs, porosity created by late-stage dissolution is facies specific and predominantly moldic and enhanced primary (skeletal and interparticle). Submarine cements occlude some primary porosity in each reef facies. However, back-reef facies result in higher observed porosity because primary permeability allowed greater access for dissolving fluids. Stylolites that form and remain open within reef packstone-grainstone facies act as avenues for fluids that dissolve skeletal grains along narrow adjacent zones within the rock matrix. This late-stage dissolution can produce significant porosity where primary permeability is still preserved. Limited early submarine cementation inhibits burial compaction and acts to preserve porosity. Where stylol tes extend into back-reef mudstone and wackestone facies, a higher percentage of impermeable muds and a limited amount of skeletal grains available for dissolution prevent development of significant porosity. Late-stage subsurface dissolution within reefal buildups, whether by widespread, pervasive fluid migration or as fronts along stylolite zones, is commonly facies-controlled by primary porosity and permeability characteristics. Thus, the distribution and degree of submarine cementation are important to both the early and late development of porosity in reef reservoir facies, even though sometimes for indirect reasons. Figure End_of_Article - Last_Page 503------------

Laser-Induced Liquid Zone Migration of Metal-Silicon Alloys in Si

ABSTRACTPatterns of sharp narrow vertical p-n junctions were produced by scanning a laser beam over the surface of a silicon wafer coated on the backsurface by either Au-Sb, Al or Ga. Formation of the junctions occurs by liquid zone migration along the thermal gradient induced by the laser beam. Nd-YAG as well as CO2 laser light was employed and the dependance of migration zone width, velocity, front stability and structure on the different laser wave lengths was studied. Structural investigations of the regrown layers included optical microscopy, SEM and TEM studies as well as spreading resistance measurements to ascertain the behaviour of the various p-n junctions produced. Annealing treatments of the migrated zones were performed to alleviate the stresses produced during the migration experiments.

Diffusion model of tumor vascularization and growth.

A diffusion model of tumor growth, vascularization and necrosis is used to analyze experimental data describing the temporal changes in tumor cell and blood vessel radial distributions in a host-tissue field transplanted with a fibrosarcoma. The experimental results showed a peak density of vessels occurring at the advancing migration front of the tumor and a decline in the vessel surface area at the tumor center with time. The peak density of tumor cells shifts away from the tumor center with time. These dynamic changes can be explained by a mathematical model which views the process as one of diffusion and proliferation in time and space. Coupled diffusion equations with nonlinear source and sink terms describe the proliferation, death, and migration of tumor cells and vascular surface area. The concept of an angiogenic factor elaborated by tumor cells is incorporated.

Nocturnal Passerine Migration and Cold Front Passages in Autumn: A Combined Radar and Field Study

Nocturnal Passerine Migration and Cold Front Passages in Autumn: A Combined Radar and Field Study

The Edge of the Forest in Alaska and the Reasons for Its Position

Transitions from one sort of vegetation to another-tension zones they have been called-are places of unusual interest to botanists. For along these lines, if they be in fact under tension from the struggles of diverse plants for ascendency, are afforded our best opportunities for unravelling the complex of factors which condition the success of the types concerned. Sometimes such vegetation lines, like the zones around a pond, are evidently due to transitions in physical or climatic conditions, each type of vegetation being clearly restricted to the habitat suitable to its own growth. In other cases the cause of the change in vegetation is not so readily apparent. Some of these obscure transitions are due to less obvious physical factors which may be made out by study or experiment. Others, conceivably at least, might represent actually moving migration fronts in no way related to physical factors. It was an attempt to gain an understanding of one of these more obscure boundaries that led to the present paper. Among such tension zones the timber-line where trees give way to smaller plants holds a peculiar interest. When a resident of a forested region contemplates a treeless area, whether an isolated mountain peak that rises above timber-line or a general region like the Arctic vegetation zone, he is inevitably led to conjecture as to the factors which prevent the trees, aggressive invaders farther down, from penetrating into the bare area. The inevitable speculation thus aroused has led to the opinion commonly held that beyond the timberline, temperature or some other physical factor is too severe for tree growth. It should be pointed out, however, that this opinion was reached many years before any critical examination of the facts of the case had been made. Perusal of the literature will indeed show that thorough studies of timberline ecology are surprisingly few considering the great importance of the problem, both theoretical and practical. It so happens that the edge of the forest in southwestern Alaska crosses the area devastated by Katmai volcano, whose great eruption it has been the writer's good fortune to study under the auspices of the National Geographic Society. During the fifteen years covered by the Katmai expeditions there has thus been afforded an exceptional opportunity for studying the forest boundary as a side line in connection with other researches into the eruption and its effect on vegetation.