Showing papers by "University of Hamburg published in 1994"
29 Sep 1994
TL;DR: In this article, the authors provide a clear and comprehensive introduction to scanning tunnelling microscopy and related scanning probe techniques, including the design and instrumentation of practical STM and associated systems, as well as applications in condensed matter physics, chemistry, biology, and nanotechnology.
Abstract: The investigation and manipulation of matter on the atomic scale have been revolutionised by scanning tunnelling microscopy and related scanning probe techniques. This book is the first to provide a clear and comprehensive introduction to this subject. Beginning with the theoretical background of scanning tunnelling microscopy, the design and instrumentation of practical STM and associated systems are described in detail, as are the applications of these techniques in fields such as condensed matter physics, chemistry, biology, and nanotechnology. Containing 350 illustrations, and over 1200 references, this unique book represents an ideal introduction to the subject for final-year undergraduates in physics or materials science. It will also be invaluable to graduate students and researchers in any branch of science where scanning probe techniques are used.
1,027 citations
TL;DR: In this article, the authors propose spacetime uncertainty relations motivated by Heisenberg's uncertainty principle and by Einstein's theory of classical gravity, which is described by a non-commutative algebra whose commutation relations do imply our uncertainty relations.
826 citations
TL;DR: In this article, the authors introduced a hadronic scale R0 through the force F(r) between static quarks at intermediate distances r. Since R0 is well defined and can be calculated accurately in a Monte Carlo simulation, it is an ideal quantity to set the scale.
780 citations
TL;DR: The data show a strong correlation between disease phenotype and the nature and position of theRET mutation, suggesting that a simple, constitutive activation of the RET tyrosine kinase is unlikely to explain the events leading to MEN 2A and FMTC.
Abstract: We have analysed 118 families with inherited medullary thyroid carcinoma (MTC) for mutations of the RET proto-oncogene. These included cases of multiple endocrine neoplasia types 2A (MEN 2A) and 2B (MEN 2B) and familial MTC (FMTC). Mutations at one of 5 cysteines in the extracellular domain were found in 97% of patients with MEN 2A and 86% with FMTC but not in MEN 2B patients or normal controls. 84% of the MEN2A mutations affected codon 634. MEN 2A patients with a Cys634 to Arg substitution had a greater risk of developing parathyroid disease than those with other codon 634 mutations. Our data show a strong correlation between disease phenotype and the nature and position of the RET mutation, suggesting that a simple, constitutive activation of the RET tyrosine kinase is unlikely to explain the events leading to MEN 2A and FMTC.
614 citations
TL;DR: The major direct solutions to the three point perspective pose estimation problems are reviewed from a unified perspective beginning with the first solution published in 1841 by a German mathematician and continuing through the solutions published in the German and then American photogrammetry literature, and most recently in the current computer vision literature.
Abstract: In this paper, the major direct solutions to the three point perspective pose estimation problems are reviewed from a unified perspective beginning with the first solution which was published in 1841 by a German mathematician, continuing through the solutions published in the German and then American photogrammetry literature, and most recently in the current computer vision literature. The numerical stability of these three point perspective solutions are also discussed. We show that even in case where the solution is not near the geometric unstable region, considerable care must be exercised in the calculation. Depending on the order of the substitutions utilized, the relative error can change over a thousand to one. This difference is due entirely to the way the calculations are performed and not due to any geometric structural instability of any problem instance. We present an analysis method which produces a numerically stable calculation.
574 citations
TL;DR: In selected patients with multivessel coronary disease, PTCA and CABG as initial treatments resulted in equivalent improvement in angina after one year, however, in order to achieve similar clinical outcomes, the patients treated with P TCA were more likely to require further interventions and antianginal drugs, whereas the patients treating with CABGs were morelikely to sustain an acute myocardial infarction at the time of the procedure.
Abstract: Background The standard treatment for patients with symptomatic multivessel coronary artery disease is coronary-artery bypass grafting (CABG). Percutaneous transluminal coronary angioplasty (PTCA) is widely used as an alternative approach to revascularization, but a systematic comparison of the two procedures is needed. We compared the outcomes in patients one year after complete revascularization with CABG or PTCA. Methods A total of 8981 patients with multivessel coronary disease were screened at eight clinical sites, and 359 patients were randomly assigned to undergo CABG (177 patients) or PTCA (182 patients). Enrollment required that complete revascularization of at least two major vessels supplying different myocardial regions be deemed clinically necessary and technically feasible. Results Among the patients in the CABG group, an average (±SD) of 2.2 ±0.6 vessels were grafted, and among those in the PTCA group, 1.9 ±0.5 vessels were dilated. After CABG, hospitalization was longer (median, 19 days, a...
554 citations
01 Jan 1994
413 citations
TL;DR: A reproducible transformation system for hexaploid wheat was developed based on particle bombardment of scutellar tissue of immature embryos and the presence of introduced foreign genes in the genomic DNA of the transformants and both marker genes were present in all plants analysed.
Abstract: A reproducible transformation system for hexaploid wheat was developed based on particle bombardment of scutellar tissue of immature embryos. Particle bombardment was carried out using a PDS 1000/He gun. Plant material was bombarded with the plasmid pDB1 containing the beta-glucuronidase gene (uidA) under the control of the actin-1 promoter of rice, and the selectable marker gene bar (phosphinothricin acetyltransferase) under the control of the CaMV 35S promoter. Selection was carried out using the herbicide Basta (Glufosinate-ammonium). From a total number of 1050 bombarded immature embryos, in seven independent transformation experiments, 59 plants could be regenerated. Putative transformants were screened for enzyme activity by the histochemical GUS assay using cut leaf material and by spraying the whole plants with an aqueous solution of the herbicide Basta. Twelve regenerants survived Basta spraying and showed GUS-activity. Southern-blot analysis indicated the presence of introduced foreign genes in the genomic DNA of the transformants and both marker genes were present in all plants analysed. To date, four plants have been grown to maturity and set seed. Histochemically stained pollen grains showed a 1:1 segregation of the uidA gene in all plants tested. A 3:1 segregation of the introduced genes was demonstrated by enzyme activity tests and Southern blot analysis of R1 plants.
349 citations
TL;DR: The results demonstrate that the mutants were impaired in the accumulative phase of biofilm production by S. epidermidis by mediating intercellular adhesion.
Abstract: The primary attachment to polymer surfaces followed by accumulation in multilayered cell clusters leads to production of Staphylococcus epidermidis biofilms, which are thought to contribute to virulence in biomaterial-related infections. We isolated Tn917 transposon mutants of biofilm-producing S. epidermidis 13-1, which were completely biofilm negative. In pulsed-field gel electrophoresis no obvious deletions of the mutants were noted. The Tn917 insertions of mutants M10 and M11 were located on different EcoRI fragments but on identical 60-kb SmaI and 17-kb BamHI chromosomal fragments. Linkage of transposon insertions of mutants M10 and M11 with the altered phenotype was demonstrated by phage transduction, whereas the several other mutants apparently represented spontaneous variants. In a primary attachment assay with polystyrene spheres, no significant difference between any of the mutants and the wild type could be detected. Cell clustering as an indication of intercellular adhesion, which is a prerequisite for accumulation in multilayered cell clusters, was not detected with any mutant. These results demonstrate that the mutants were impaired in the accumulative phase of biofilm production. Mutants M10 and M11 did not produce detectable amounts of a specific polysaccharide antigen (D. Mack, N. Siemssen, and R. Laufs, Infect. Immun. 60:2048-2057, 1992), whereas substantially reduced amounts of antigen were produced by the spontaneous variants. Hexosamine was determined as the major specific component of the antigen enriched by gel filtration of biofilm-producing S. epidermidis 1457 because almost no hexosamine was detected in material prepared from the isogenic biofilm-negative transductant 1457-M11, which differentiates the antigen from other S. epidermidis polysaccharide components. Our results provide direct genetic evidence for a function of the antigen in the accumulative phase of biofilm production by S. epidermidis by mediating intercellular adhesion.
343 citations
TL;DR: 6- BH4 seems to control melanin biosynthesis in the human epidermis, whereas 7-BH4 may initiate depigmentation in patients with vitiligo.
Abstract: The participation of (6R) 5,6,7,8-tetrahydrobiopterin (6-BH4) in regulating the tyrosine supply for melanin biosynthesis was investigated by the examination of human keratinocytes, melanocytes, and epidermal suction blisters from normal human skin and from patients with the depigmentation disorder vitiligo. Cells, as well as total epidermis, contained high phenylalanine hydroxylase activities and also displayed the capacity to synthesize and recycle 6-BH4, the essential cofactor for this enzyme. In vitiligo, 4a-hydroxy-BH4 dehydratase activity was extremely low or absent, yielding an accumulation of the nonenzymatic by-product 7-tetrahydrobiopterin (7-BH4) at concentrations up to 8 x 10(-6) M in the epidermis. This by-product is a potent competitive inhibitor in the phenylalanine hydroxylase reaction with an inhibition constant of 10(-6) M. Thus, 6-BH4 seems to control melanin biosynthesis in the human epidermis, whereas 7-BH4 may initiate depigmentation in patients with vitiligo.
322 citations
TL;DR: In this paper, a detailed spectroscopic characterization of GdVO4, a new laser crystal with high effective absorption and emission cross sections, has been carried out and the temperature dependences of lifetime, linewidths, and cross sections have been determined.
Abstract: We have carried out a detailed spectroscopic characterization of Nd: GdVO4, a new laser crystal with high effective absorption and emission cross sections. The accidental degeneracy of the upper4
F
3/2 laser level decreases the number of emission lines and creates -together with the anisotropic crystal field - high emission cross sections (7.6 × 10−19 cm2 at 1.06 µm and 300 K). In addition, the lines are strongly homogeneously broadened (1.6 nm for the 808.4 nm diode-laser pump transition). The temperature dependences of lifetime, linewidths, and cross sections have been determined. Slope efficiencies up to 57% with respect to the absorbed diode-laser pump power and output powers up to 0.8 W have been achieved at 1.06 µm from a 2 mm long crystal. Intracavity second-harmonic generation, using a KTP crystal, is demonstrated.
TL;DR: In this paper, the authors examined the influence of surface heat flux, wind stress and turbulent kinetic energy (TKE) over the period 1970-88 on the variability of the Pacific Ocean.
Abstract: Variability of the Pacific Ocean is examined in numerical simulations with an ocean general circulation model forced by observed anomalies of surface heat flux, wind stress and turbulent kinetic energy (TKE) over the period 1970-88. The model captures the 1976-77 winter time climate shift in sea surface temperature, as well as its monthly, seasonal and longer term variability as evidenced in regional time series and empirical orthogonal function analyses. Examination of the surface mixed-layer heat budget reveals that the 1976-77 shift was caused by a unique concurrance of sustained heat flux input anomalies and very strong horizontal advection anomalies during a multi-month period preceding the shift in both the central Pacific region (where cooling occurred) and the California coastal region (where warming occurred). In the central Pacific, the warm conditions preceding and the cold conditions following the shift tend to be maintained by anomalous vertical mixing due to increases in the atmospheric momentum flux (TKE input) into the mixed layer (which deepens in the model after the shift) from the early 1970s to the late 1970s and 1980s. Since the ocean model does not contain feedback to the atmosphere and it succeeds in capturing the major features of the 1976-77 shift, it appears that the midlatitude part of the shift was driven by the atmosphere, although effects of midlatitude ocean-atmosphere feedback are still possible. The surface mixed-layer heat budget also reveals that, in the central Pacific, the effects of heat flux input and vertical mixing anomalies are comparable in amplitude while horizontal advection anomalies are roughly half that size. In the California coastal region, in contrast, where wind variability is much weaker than in the central Pacific, horizontal advection and vertical mixing effects on the mixed layer heat budget are only one-quarter the size of typical heat flux input anomalies.
TL;DR: Glycosylation occurs between domains D8 and D9, leading to a revision of the transmembrane topology model for ClC channels.
Abstract: We have cloned two closely related putative Cl- channels from both rat kidney (designated rClC-K1 and rClC-K2) and human kidney (hClC-Ka and hClC-Kb) by sequence homology to the ClC family of voltage-gated Cl- channels. While rClC-K1 is nearly identical to ClC-K1, a channel recently isolated by a similar strategy, rClC-K2 is 80% identical to rClC-K1 and is encoded by a different gene. hClC-Ka and hClC-Kb show approximately 90% identity, while being approximately 80% identical to the rat proteins. All ClC-K gene products are expressed predominantly in the kidney. While rClC-K1 is expressed strongly in the cortical thick ascending limb and the distal convoluted tubule, with minor expression in the S3 segment of the proximal tubule and the cortical collecting tubule, rClC-K2 is expressed in all segments of the nephron examined, including the glomerulus. Since they are related more closely to each other than to the rat proteins, hClC-Ka and hClC-Kb cannot be regarded as strict homologs of rClC-K1 or rClC-K2. After injection of ClC-K cRNAs into oocytes, corresponding proteins were made and glycosylated, though no additional Cl- currents were detectable. Glycosylation occurs between domains D8 and D9, leading to a revision of the transmembrane topology model for ClC channels.
TL;DR: It is demonstrated in a variety of cell types, including lymphocytes and endometrial stroma, that Pit-1 is not involved in the regulation of dPRL promoter/reporter gene constructs carrying 3 kb 5'-flanking DNA, and experiments show that activated PR does not confer direct transcriptional control on the d PRL promoter.
Abstract: Expression of the human PRL (hPRL) gene in extrapituitary sites such as the uterus (decidualized endometrial stroma and myometrium) and cells of the hematopoietic lineage is directed by an alternative promoter which is located approximately 6 kilobases (kb) upstream of the pituitary-specific start site. In order to delineate the tissue-specific mechanisms governing the control of nonpituitary PRL gene expression, we have cloned and sequenced 3 kb 5'-flanking DNA of the upstream decidual/lymphoid (dPRL) promoter. Based on sequence homology we identified two binding motifs for Pit-1 and seven half-sites for glucocorticoid receptor/progesterone receptor (PR) binding. We focused our studies on the role of Pit-1 and of PR as potential transcriptional regulators, since the POU domain protein Pit-1 is essential in the control of pituitary PRL expression, and progesterone induces decidual transformation of the endometrial stroma, a differentiation process during which the decidual PRL gene is activated. We demonstrate in a variety of cell types, including lymphocytes and endometrial stroma, that Pit-1 is not involved in the regulation of dPRL promoter/reporter gene constructs carrying 3 kb 5'-flanking DNA. Our experiments also show that activated PR does not confer direct transcriptional control on the dPRL promoter. When we compared the activity of the transfected dPRL promoter in PRL-secreting and nonsecreting lymphoid cells, we found that the 3 kb 5'-flanking region of the dPRL promoter did not contain elements restricting expression to only those lymphocytes that produce PRL but allowed expression of fusion reporter genes irrespective of the status of the endogenous PRL gene. This was in sharp contrast to endometrial cells where 3 kb 5'-flanking DNA conferred strong transcriptional activation on the dPRL promoter in decidualized endometrial stromal cells actively secreting PRL, but did not allow transcription in undifferentiated non-PRL-secreting endometrial stromal cells. Activation of the dPRL promoter construct in these undifferentiated cells could however be induced by the addition of cAMP, in the absence of progesterone, suggesting that a signal transduced through the cAMP signaling pathway is a primary inducer of decidual PRL gene expression.
TL;DR: RNA/DNA ratios in individual herring larvae (Clupea harengus) were measured and proved suitable for determining nutritional status and showed an increase with age or length of the larvae and was less pronounced in starving larvae compared to fed larvae.
Abstract: RNA/DNA ratios in individual herring (Clupea harengus) larvae (collected from Kiel Bay, Baltic Sea, in 1989) were measured and proved suitable for determining nutritional status. Significant differences between fed and starving larvae appeared after 3 to 4 d of food deprivation in larvae older than 10 d after hatching. The RNA/DNA ratio showed an increase with age or length of the larvae and was less pronounced in starving larvae compared to fed larvae. The individual variability of RNA/DNA ratios in relation to larval length of fed larvae and of larvae deprived of food for intervals of 6 to 9 d is presented. Based on the length dependency and the individual variability found within the RNA/DNA ratios, a laboratory calibration is given to determine whether a larva caught in the field has been starving or not. An example for a field application is shown.
TL;DR: The C++ class library PROFIL is presented which provides a user friendly environment for implementing interval algorithms and an implementation in C using a lower/upper bound representation of intervals and directed roundings is presented.
Abstract: The interval data type is currently not supported in common programming languages. Therefore the implementation of algorithms using interval arithmetic requires special programming environments or at least special libraries. In this paper we present the C++ class library PROFIL which provides a user friendly environment for implementing interval algorithms. The main goals in the design of PROFIL were speed and portability. Therefore all interval operations in PROFIL use BIAS (Basic Interval Arithmetic Subroutines) [16]. BIAS defines a concise and portable interface for the basic scalar, vector, and matrix operations. The interface is independent of a specific interval representation or computation but permits machine specific and fast implementations. Based on this general specification we present an implementation in C using a lower/upper bound representation of intervals and directed roundings. By using few assembler instructions for switching the rounding modes and avoiding sign tests and rounding mode switches wherever possible, the computational costs of the interval operations were reduced significantly. This is especially important for RISC machines, where floating point instructions can be executed in few machine cycles. Comparisons with other interval arithmetic packages show an improvement in speed of about one order of magnitude.
TL;DR: It was concluded that, in survivors of cardiac arrest, propafenone treatment is less effective than implantable defibrillator treatment, and a significantly higher incidence of total mortality, sudden death, and cardiac arrest recurrence or sudden death was found in the propafanone group compared with the implantabledefibrillators-treated patients.
TL;DR: In this article, the authors exploit the properties of human mutations in the muscle chloride channel, ClC-1, to explore its multimeric structure, based on analysis of the dominant negative effects of ClC1 mutations causing myotonia congenita (MC, Thomsen's disease).
Abstract: Voltage-gated ClC chloride channels play important roles in cell volume regulation, control of muscle excitability, and probably transepithelial transport. ClC channels can be functionally expressed without other subunits, but it is unknown whether they function as monomers. We now exploit the properties of human mutations in the muscle chloride channel, ClC-1, to explore its multimeric structure. This is based on analysis of the dominant negative effects of ClC-1 mutations causing myotonia congenita (MC, Thomsen's disease), including a newly identified mutation (P480L) in Thomsen's own family. In a co-expression assay, Thomsen's mutation dramatically inhibits normal ClC-1 function. A mutation found in Canadian MC families (G230E) has a less pronounced dominant negative effect, which can be explained by functional WT/G230E heterooligomeric channels with altered kinetics and selectivity. Analysis of both mutants shows independently that ClC-1 functions as a homooligomer with most likely four subunits.
TL;DR: A system for the biolistic transformation of barley using freshly-isolated microspores as the target tissue led, on average, to the recovery of one plant per 1×107 bombarded microspore.
Abstract: We have developed a system for the biolistic transformation of barley using freshly-isolated microspores as the target tissue. Independent transformation events led, on average, to the recovery of one plant per 1×10(7) bombarded microspores. Putative transformants have been regenerated using phosphinothricin as a selective agent. R0 plants have been transferred to soil approximately 2 months after bombardment. Integration of the marker genes bar and uidA has been confirmed by Southern analysis. The marker genes are inherited in all progeny plants confirming the expected homozygous nature of the R0 plants.
TL;DR: In this paper, three numerical experiments have been conducted to explore the relative roles of midlatitude and tropical SSTs in producing atmospheric variability, and the results indicate that the response of the observed atmospheric circulation to North Pacific SST anomalies is much smaller and much less systematic than the response to tropical sSTs.
Abstract: Three numerical experiments have been conducted to explore the relative roles of midlatitude and tropical SSTs in producing atmospheric variability. In these experiments, anomalous observed SSTs were prescribed in 1) the tropical oceans only, 2) the midlatitude oceans only, and 3) globally. These simulations were conducted with the same atmospheric model and covered the period 1970–88. Although each simulation reproduced some aspects of the observed circulation variability, the results from the two experiments including tropical SSTs performed best by most measure particularly in showing temporal signals that agreed with those seen in the observations. The results indicate that the response of the observed atmospheric circulation to North Pacific SST anomalies is much smaller and much less systematic than the response to tropical SSTs. It is suggested that the apparent links between North Pacific SSTs and the observed winter circulation am due primarily to the effects on oceanic forcing by the re...
TL;DR: It is shown that the relation between [x(0)] and [ x (k) ] is ambiguous, Hence, the qualitative model is nondeterministic and necessary and sufficient conditions are derived under which nondetergetic or stochastic automata represent qualitative models of a linear autonomous system.
TL;DR: In this article, an elementary teacher and first graders are observed when they ascribe mathematical meanings of numbers and of numerical operations to empirical phenomena, and interactional regularities help the participants to cope with ambiguity.
Abstract: The teaching-learning process is considered as a social interaction. In this microethnographical case study an elementary teacher and first graders are observed when they ascribe mathematical meanings of numbers and of numerical operations to empirical phenomena. Because of the differences of their ascriptions, the teacher and the students negotiate mathematical meanings. Also interactional regularities help the participants to cope with ambiguity. According to different theoretical approaches, the text discusses some indirect relations between social interaction and mathematics learning. Several classrooms episodes are interpreted to illustrate specific theoretical concepts.
TL;DR: In this paper, the effect of rare-earth ions (La, Pr, Nd, and Gd) on the thermal behavior and on the catalytic activity for methane oxidation has been studied.
TL;DR: The data confirm earlier results of a prevalence of thyroid disease and the presence of thyroid antibodies, whereas other diseases are a random event.
Abstract: In the past, several authors described an association of vitiligo with autoimmune disorders and the presence of different tissue autoantibodies. A review of the literature showed large differences in the results. Therefore, 321 patients with vitiligo (male/female ratio 114/207) were examined to see whether the frequencies of associated diseases and phenomena (i.e. Koebner phenomenon, canities praecox, halo nevi, poliosis circumscripta), the number of pigmented lesions and the presence of autoantibodies are of significance in order to support (a) a subentity of childhood vitiligo and (b) whether there is a true predisposition or association of autoimmune or other diseases in this group of patients. The data confirm earlier results of a prevalence of thyroid disease and the presence of thyroid antibodies, whereas other diseases are a random event. 6.2% of the patients had congenital nevi compared with 2.8% in a normal healthy population. Based on the results of this study and the significant higher risk for development of melanomas in this patient group, an annual checkup is recommended.
TL;DR: The possible influence of the El Nino/Southern Oscillation (ENSO) warm and cold extremes on mid-latitude circulation regimes in the North Atlantic/European sector is described in terms of a phenomenological, statistical and physical analysis of observational data as discussed by the authors.
Abstract: The possible influence of the El Nino/Southern Oscillation (ENSO) warm and cold extremes on mid-latitude circulation regimes in the North Atlantic/European sector is described in terms of a phenomenological, statistical and physical analysis of observational data. (1) The European circulation patterns (after Hess-Brezowsky, 1977) are combined to a binary set of cyclonic and anticyclonic (low and high pressure) centres of action. They reveal a regional ENSO response with predominantly cyclonic (anticyclonic) Grosswetter for warm (cold) ENSO events in winters at the peak of the episode. (2) Standard climate statistics of the same winter seasons (surface pressure, temperature and precipitation anomalies) supplement the Grosswetter phenomenology. They suggest a shift of the tail end of the cross Atlantic storm track and its rainbearing frontal systems from a more northern route (during warm events) to a more zonal orientation (in cold events). (3) Finally, the transient and stationary eddy–mean flow interaction is diagnosed from daily hemispheric 500 mb geopotential height fields. They are composited about most extreme anomalies in Europe (independent of ENSO) defined by the amplitude of the first simultaneous EOF of normalized monthly mean pressure, temperature and precipitation at 40 stations. Thus (upstream location and intensity of) dynamic sources of wave activity flux in the western North-Atlantic cyclogenesis area can be identified. They are associated with European climate anomalies and may represent the connection linking ENSO and Europe under favourable conditions. DOI: 10.1034/j.1600-0870.1994.00015.x
TL;DR: The following servomechanism problem is solved: Determine a l-universal adaptive strategy to control the output to track any reference signal in W 1,∞, with tracking error asymptotic to a ball of arbitrary prescribed radius λ >0.
TL;DR: In this article, the authors measured the elastic light vector meson cross sections at an average υp center of mass energy of 180 GeV with the ZEUS detector at HERA.
Abstract: Photon proton cross sections for elastic light vector meson production, σelνp, inelastic diffractive production, σndνp, non-diffractive production, σdνp, as well as the total cross section, σtotνp, have been measured at an average υp center of mass energy of 180 GeV with the ZEUS detector at HERA. The resulting values are σelνp = 18 ± 7 μb, σdνp = 33 ± 8 μb, σndνp = 91 ± 11 μb, and σtotνp 143 ± 17 μb, where the errors include statistical and systematic errors added in quadrature.
TL;DR: The recent review of deep-sea meiofauna was discussed, which focused mainly on the abundance and biomass data from different oceans and on the relationship between the biomass of the meiobenthos and that of other faunal components.
Abstract: This chapter throws the attention on the meiobenthos of the deep northeast Atlantic. The main purpose of this chapter is to summarize new results from an area lying between 15°N and 53°N and extending from the continental margin of western Europe and northwest Africa to the Mid-Atlantic Ridge. It considers first the nature and scope of meiofaunal research in the northeast Atlantic and then discuss the environmental parameters, which are believed to influence meiofaunal organisms. This chapter then discusses the various types and scales of pattern observed among meiofaunal populations within the study area, progressing from the large-scale bathymetric and latitudinal trends and then to small-scale horizontal patterns within particular areas. Faunal densities and faunal composition are considered separately and compared with data from other regions. This chapter also deals with the distribution of meiofauna within sediment profiles and the temporal variability of populations. This chapter concludes by discussing the recent review of deep-sea meiofauna, which focused mainly on the abundance and biomass data from different oceans and on the relationship between the biomass of the meiofauna and that of other faunal components
TL;DR: In 651 patients mapping of the prostate by 6 systematic sextant ultrasonography guided biopsies was performed without major side effects using the automatic biopsy gun, the histological findings provided data on patients with normal and abnormal prostates as determined by digital rectal examination.
TL;DR: In this paper, the authors examined both the supply of the substrate (L-tyrosine) and the regulation of tyrosinase in the epidermis of subjects with vitiligo.