bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clonidine improves postprandial baroreflex control in familial dysautonomia
Authors: Marthol H. , Tutaj M. , Brys M. , Brown C. M. , Hecht M. J. , Berlin D. , Axelrod F. B. , Hilz M. J. 
Published: September 2003

AbstractBackground  Patients with familial dysautonomia (FD) frequently experience hypertensive crises after gastrostomy feeding. The central α2‐agonist clonidine attenuates feeding‐induced crises. The aim of this study was to assess the effect of clonidine on cardiovascular autonomic modulation and particularly baroreflex sensitivity in familial dysautonomia after gastrostomy feeding.Material and methods  In nine patients, we monitored the RR‐interval and systolic blood pressure at supine rest before (baseline 1) and after gastrostomy feeding (GF1). One day later, recordings were repeated after clonidine intake (baseline 2, GF2). We determined spectral powers of RR‐interval and systolic blood pressure in the low‐ (LF) and high‐frequency range (HF). Sympathovagal balance was determined from the LF/HF ratio of RR‐interval. Baroreflex sensitivity was assessed from the α‐index of systolic blood pressure and RR‐interval.Results  Gastrostomy feeding decreased RR‐interval, while systolic blood pressure remained stable. Clonidine induced higher RR‐intervals before and after gastrostomy feeding but decreased systolic blood pressure at baseline only. Gastrostomy feeding decreased HF‐power of RR‐interval significantly without clonidine, but only slightly after premedication. Clonidine increased the HF‐power of RR‐interval slightly at baseline and significantly after gastrostomy feeding. Gastrostomy feeding increased the LF/HF ratio without clonidine only. Clonidine decreased the LF/HF ratio at baseline and after gastrostomy feeding. Gastrostomy feeding did not change baroreflex sensitivity, but baroreflex sensitivity was higher at visit 2 than visit 1.Conclusions  In familial dysautonomia, clonidine augments baroreflex sensitivity and parasympathetic modulation. The resulting cardiovascular stabilization might attenuate feeding‐induced crises.
Plasma angiopoietin‐1, angiopoietin‐2 and Tie‐2 in breast and prostate cancer: a comparison with VEGF and Flt‐1
Authors: Caine G. J. , Blann A. D. , Stonelake P. S. , Ryan P. , Lip G. Y. H. 
Published: September 2003

AbstractBackground  Angiogenesis is essential for tumour growth and metastasis, and is coordinated by several classes of growth factors mediating their effect through receptors linked, in turn, to tyrosine kinase. These growth factors include angiopoietin‐1 (Ang‐1), angiopoietin‐2 (Ang‐2) and vascular endothelial growth factor (VEGF), which act through receptors Flt‐1 and Tie‐2.Materials and methods  In order to further determine abnormalities in levels of Ang‐1, Ang‐2, Tie‐2, sFlt‐1 and VEGF in human cancer (and their interrelationships), these molecules were measured in plasma from 30 patients with breast cancer, 30 patients with prostate cancer and 12 healthy controls per cancer group.Results  In breast cancer, levels of Ang‐1 (P = 0·0005), Ang‐2 (P = 0·0173), Tie‐2 (P = 0·0001), and VEGF (P = 0·0001) were all significantly raised, and plasma levels of sFlt‐1 (P = 0·045) were significantly reduced compared with controls. However, in prostate cancer, only levels of VEGF and Tie‐2 were significantly higher (both P= 0·001). There were no significant differences between levels of any molecule between the two groups of cancer. The only difference between the healthy control groups was lower Ang‐1 in the women compared with men. Significant correlations were found between levels of Ang‐1 and Tie‐2 both in breast (r = 0·498, P= 0·005) and prostate cancer (r = 0·643, P= < 0·001). Angiopoietin‐1 was also positively correlated with Ang‐2 in both breast (r = 0·422, P= 0·02) and prostate cancer (r = 0·543, P= 0·002).Conclusions  Abnormal levels of Ang‐1, Ang‐2 and their receptor, Tie‐2, are present in breast and prostate cancer, and their interrelationships may be important in the pathophysiology of these conditions.
Impact of parturition on iron status in nonanaemic iron deficiency
Authors: Krafft A. , Huch R. , Breymann C. 
Published: September 2003

AbstractBackground  Iron‐deficient nonanaemic parturients risk underdiagnosis as a result of the reliance on postpartum ferritin and haemoglobin as markers of iron status. Ferritin is an acute‐phase protein whose levels increase during the inflammatory response, as occurs after delivery. Our aims were to evaluate the impact of parturition on iron status, erythropoiesis and the inflammatory response, and identify the optimal parameters and timing for diagnosing iron deficiency in the presence of postpartum inflammation.Materials and methods  Conventional parameters of iron status, erythropoiesis and the inflammatory response (serum ferritin, serum iron, transferrin saturation, C‐reactive protein) were compared with more recent parameters [soluble transferrin receptors (sTfR), hypochromic red cells, reticulocyte indices] within 48 h either side of delivery in 64 iron‐deficient nonanaemic women (defined by a prepartum serum ferritin ≤ 15 µg L−1, and a pre‐ and postpartum haemoglobin of ≥ 11·0 g dL−1 and ≥ 10·0 g dL−1, respectively).Results  Mean sTfR decreased pre to postpartum from 7·3 to 5·8 µg mL−1 (P < 0·01), while mean serum ferritin increased from 9·7 to 16·9 µg L−1 (P < 0·01). Serum ferritin did not correlate with haemoglobin pre or postpartum (r = 0·04, P = 0·7; r = 0·2, P = 0·09), but a correlation persisted postpartum between hypochromic red blood cells and haemoglobin (r = −0·26; P < 0·05). The percentage of hypochromic red cells remained virtually unchanged pre‐ and postpartum (4·0% vs. 3·8%; NS). Postpartum mean reticulocyte haemoglobin content (CHr) was 27·1 ± 1·6 pg.Conclusion  Iron status should be tested prepartum, in the absence of an inflammatory response, rather than in the early postpartum. A valuable additional parameter, where available, might be the hypochromic red cell percentage, which is virtually uninfluenced by the inflammatory response. Furthermore, hypochromic red cell percentage, CHr and sTfR can be helpful to differentiate between functional iron deficiency and depleted iron stores.
Erythropoietin as an angiogenic factor
Authors: Ribatti D. , Vacca A. , Roccaro A. M. , Crivellato E. , Presta M. 
Published: September 2003

AbstractErythropoietin (Epo) is produced by the fetal liver and adult kidney and is an essential stimulator of erythropoiesis. It has, however, been shown to modulate host cellular signal transduction pathway to perform many other functions. New sites of Epo production have been found, such as the female reproductive organs and central nervous system. This review summarizes the involvement of Epo in the regulation of angiogenesis in both normal and pathological conditions.
From particles to individuals: modelling the early stages of anchovy (Engraulis capensis/encrasicolus) in the southern Benguela
Authors: Mullon C. , Fréon P. , Parada C. , Van Der Lingen C. , Huggett J. 
Published: September 2003

AbstractSeveral individual‐based models (IBMs) have recently been developed to improve understanding of factors impacting on recruitment variability of anchovy (Engraulis capensis/encrasicolus) in the southern Benguela. These IBMs have focused on early life history stages (eggs through to post‐larvae) as it is thought that variations in anchovy recruitment strength are primarily driven by biological and/or physical factors impacting on these stages. The pelagic zone of the Benguela system constitutes an ideal system for studying the coupling between biological and physical processes; in the IBMs this coupling is obtained by releasing particles endowed with biological properties in the virtual currents resulting from the output of a hydrodynamic model of the southwestern coast of South Africa. The particles are tracked through virtual time and space and their final locations are assessed in terms of previously defined criteria deemed to promote successful recruitment. The aim of this paper is to provide a synthesis of the results of IBMs of the early stages of anchovy in the southern Benguela constructed to date. Emphasis is placed on the methodological aspects of these studies and on the sequential link of several simulation experiments of increasing complexity. In addition to improving understanding, such an approach allows for effective interplay between modelling experiments and surveys or laboratory experiments. Details of individual IBM experiments and their results have been published elsewhere.
Potential changes in skipjack tuna (Katsuwonus pelamis) habitat from a global warming scenario: modelling approach and preliminary results
Authors: Loukos Harilaos , Monfray Patrick , Bopp Laurent , Lehodey Patrick 
Published: September 2003

AbstractRecent studies suggest a reduction of primary production in the tropical oceans because of changes in oceanic circulation under global warming conditions caused by increasing atmospheric CO2 concentration. This might affect the productivity of medium and higher trophic levels with potential consequences on marine resources such as tropical tuna. Here we combine the projections of up‐to‐date climate and ocean biogeochemical models with recent concepts of representation of fish habitat based on prey abundance and ambient temperature to gain some insight into the impact of climate change on skipjack tuna (Katsuwonus pelamis), the species that dominates present‐day tuna catch. For a world with doubled atmospheric CO2 concentration, our results suggest significant large‐scale changes of skipjack habitat in the equatorial Pacific. East of the date line, conditions could be improved by an extension of the present favourable habitat zones of the western equatorial Pacific, a feature reminiscent of warming conditions associated with El Niño events. Despite its simplicity and the associated underlying hypothesis, this first simulation is used to stress future research directions and key issues for modelling developments associated to global change.
Investigating remote synchronous patterns in fisheries
Authors: Fréon P. , Mullon C. , Voisin B. 
Published: September 2003

AbstractThe hypothesis that the population dynamics of distant fish stocks may be synchronized by climate variations is largely based on a few major pelagic fisheries or stocks (called here ‘target series’). We broadened the study of synchrony to all available fisheries in the world by making use of all available data in the FAO catch database during the last 50 years. We investigated synchronous patterns in remote fisheries using two different approaches. The first approach consisted of simulating catch time‐series as random walk processes and comparing the synchronies found between these time‐series to the synchronies found in FAO data. In the second approach, we applied classification algorithms to analyse synchronies in the FAO catch database. We usedK‐means clustering and neural networks to answer the following four questions: (1) Do the target series appear in the same cluster? (2) Do the clusters regroup series from the same region (local synchrony) or from distant ones (remote synchrony)? (3) Are there any numerically dominant patterns (clusters) in the catch series? (4) Do the species displaying the same pattern share some common bio‐ecological features or ranges of abundance? Our results indicate some degree of local rather than remote synchrony. Nonetheless, it does not prove that such remote synchronies do not exist, but simply that further process studies are required before accepting them as a new paradigm.
Comparing productivity of North Atlantic cod (Gadus morhua) stocks and limits to growth production
Authors: Dutil Jean‐Denis , Brander Keith 
Published: September 2003

AbstractData from stock assessments were used to compare stock biomass, annual growth (Gs) and surplus production per capita (TSPc) and per unit biomass (TSPb) among 15 cod (Gadus morhua) stocks in the North Atlantic. TSPc ranged from 99 to 1012 g per fish among stocks and averaged 448 g per fish. TSPb ranged from 140 to 469 g kg−1 among stocks and averaged 294 g kg−1. Gs varied considerably with low growth production associated with low surplus production. On average, cod produced 724 g per fish in growth annually with cod in the least productive stock producing 7.2 times less than in the most productive stock. The stocks divided into four clusters reflecting four levels of production. Celtic Sea, Irish Sea and West Scotland cod showed the highest levels of production whereas Eastern Scotian Shelf, Northeast Arctic, Northern Grand Bank, Northern and Southern Gulf of St Lawrence showed the lowest levels. Surface and bottom salinity and temperature differed significantly among clusters in a canonical discriminant analysis. Temperature and salinity correlated with the first and second canonical variates, respectively. The most productive stocks were associated with higher bottom salinity and temperature. None of the stocks, including stocks with a fast growth rate and living at higher temperatures, had a specific growth rate (SGR) close to the maximum rate observed in laboratory experiments. The difference between observed and maximum SGR decreased at temperatures above 6°C. Very cold temperatures resulted in smaller cod also achieving SGR values closer to the maximum. Temperature is a major determinant of stock production.
Modelling climate‐related variability of tuna populations from a coupled ocean–biogeochemical‐populations dynamics model
Authors: Lehodey Patrick , Chai Fei , Hampton John 
Published: September 2003

AbstractIn the last five decades for which tuna fishing data are available, the interannual ENSO signal (SOI) and the related Pacific Decadal Oscillation (PDO) suggest two different regimes characterized by higher intensity and frequency of either El Niño or La Niña events. Recent estimates from a statistical population dynamics model (MULTIFAN‐CL) suggest that recruitment of three tuna species in the Pacific are correlated with these climate indices. While tropical tuna species like skipjack (Katsuwonus pelamis) and yellowfin (Thunnus albacares) had higher recruitments during El Niño events, the subtropical albacore species (Thunnus alalunga) showed the opposite pattern with low recruitment during El Niño and high recruitment during La Niña. The potential explanatory mechanisms for such relationships between recruitment and climate are investigated with a spatial environmental population model (SEPODYM). The model is a two‐dimensional coupled physical–biological interaction model at the ocean basin scale, and contains environmental and spatial components used to constrain the movement and the recruitment of tuna. Input datasets for the model are sea surface temperature, oceanic currents and new primary production that are simulated fields from a three‐dimensional coupled physical–biogeochemical model. The hypothesis that the spatial dynamics of temperature, currents (advection), food availability and predation constrain tuna recruitment is evaluated with an application of SEPODYM to skipjack. Simulation results showed that this hypothesis can reproduce fluctuations in the population that are similar to those estimated from the statistical model.
The selection process from larval to juvenile stages of anchovy (Engraulis encrasicolus) in the Bay of Biscay investigated by Lagrangian simulations and comparative otolith growth
Authors: Allain Gwenhael , Petitgas Pierre , Grellier Patrick , Lazure Pascal 
Published: September 2003

AbstractThe relation between growth and survival was investigated using the otolith growth data collected during repeated larval surveys (May–July) and a juvenile survey (September) undertaken in 1999 on anchovy spawning and nursery grounds in the Bay of Biscay (NE Atlantic). The paper describes the methodology for reading the larval and juvenile otoliths, for reconstructing the correspondence in space and time between juveniles and larvae using Lagrangian simulations, and for comparing the otolith growth rates among the reconstructed sub‐cohorts. Virtual buoys were released weekly on the grid of a three‐dimensional hydrodynamic model and their trajectories were tracked. The origin of an individual was determined by selecting the trajectory beginning on its hatching week and ending at the minimum distance of its sampling location on the sampling date. Larvae and juveniles with the same spatio‐temporal origin were selected and supposed to belong to the same sub‐cohorts. The surviving juveniles showed faster growth rates during their larval period than the pool of larvae they were estimated to originate from, which supports the idea of growth‐selective survival. Alternative interpretations (transport and gear selectivity) are discussed. Variations in otolith growth pattern also suggest a higher juvenile growth over the shelf break than in oceanic waters.
Dependency of larval fish survival on retention/dispersion in food limited environments: the Baltic Sea as a case study
Authors: Hinrichsen H.‐H. , Lehmann A. , Möllmann C. , Schmidt J.O. 
Published: September 2003

AbstractA three‐dimensional hydrodynamic model has been used to analyse temporally and spatially resolved circulation patterns in the Baltic Sea with special emphasis on drifting particles representing larval fish. The main purpose of this study was (i) to investigate potential drift patterns of larval fish, (ii) to identify its intra‐ and inter‐annual variability for time periods based on the timing of spawning and (iii) to analyse its seasonal and spatial variability in dependence of the atmospheric forcing conditions. For the time period 1979–1998 temporally and spatially resolved simulated flow fields were used to describe the potential drift from the centre of main reproductive effort of Baltic cod (Gadus morhua). The results of the model runs demonstrate a general change in circulation pattern from retention during a first decade (1979–1988) to dispersion in the following decade (1989–1998). This increase in dispersion was related to an increase in the variability of the local wind forcing conditions over the Baltic. The more frequent occurrence of dispersion in spring of the recent decade was accompanied by a strong decay in biomass of one of the main larval fish feeding component in the central basin, the calanoid copepod Pseudocalanus elongatus. Larger dispersion of this prey organism may have affected the spatial overlap and thus the contact rates between predator and prey. Hence, this may have resulted in a food limitation for early life stages of Baltic cod and potentially contributed to the pronounced shift in cod peak spawning time from spring to late summer. Early life stages of cod originating from late spawning fish, benefited from a stronger dispersion in late summer and autumn, into shallow coastal areas with higher calanoid abundance.
Interannual variability of Calanus helgolandicus in the English Channel
Authors: Irigoien Xabier , Harris Roger P. 
Published: September 2003

AbstractSeasonal and interannual variability in environmental variables, egg production rates and abundance of Calanus helgolandicus at a station in the English Channel have been analysed. The results show a mismatch between the timing of maximum egg production and timing of the abundance peaks. However, except for the year 1996, there was a significant relationship between the initiation of the thermocline and the timing of the maximum female abundance. We advance advection and egg mortality because of sinking as the main factors controlling the timing of the C. helgolandicus abundance peaks in the English Channel.
Long‐term changes in copepod abundance and diversity in the north‐east Atlantic in relation to fluctuations in the hydroclimatic environment
Authors: Beaugrand Gregory 
Published: September 2003

AbstractThis study investigates long‐term monthly changes in both the hydroclimatic (sea surface temperature and wind) and biological (calanoid copepod diversity, abundance of Calanus finmarchicus and Calanus helgolandicus) environment of the north‐east Atlantic. On the basis of the long‐term variability of the hydroclimatic environment, three regions are defined: the west European basin, the subarctic gyre and the North Sea. A numerical procedure, used in climatology and terrestrial ecology to detect stepwise changes, is presented and applied to both hydroclimatic and biological data. This method reveals that a regime shift in the North Sea occurred after a stepwise change in both regional hydroclimatic parameters (wind and temperature) and large‐scale hydroclimatic parameters (e.g. Northern Hemisphere Temperature anomalies). However, it is also suggested that ecological changes (e.g. calanoid copepod diversity, abundance of C. finmarchicus, C. helgolandicus) observed in the North Sea after the mid‐1980s also resulted from a major structural reorganization in calanoid copepod diversity in the north‐east Atlantic, which has been related to an increasing trend in sea surface temperature in the west European basin. Although from the present study it is difficult to quantify the respective influence of advective processes versus the impact of changes in the regional hydroclimatic environment on Calanus species, it seems likely that both processes can play a substantial role.
Decadal‐scale variability in the Kuroshio marine ecosystem in winter
Authors: Nakata Kaoru , Hidaka Kiyotaka 
Published: September 2003

AbstractInterannual variation of winter copepod biomass during the last three decades of the twentieth century was examined in the Kuroshio, off central Japan in relation to climate regime shifts. The biomass levels of large copepods in the period before 1977 and in 1999 and 2000 were higher than those in the period between 1977 and 1998. The biomass of large copepods was positively related with the Southern Oscillation Index (SOI), in winter in the Northern Hemisphere, which also showed steplike shifts in 1976/77 and 1998/99. The biomass of large copepods was largely influenced by abundance of Calanus sinicus that has high rates of production compared with small copepods under food satiated conditions. Accordingly, the climatic regime shift accompanied by the climatic change in the tropical region seems to regulate interannual variation of winter biomass of large copepods in the Kuroshio through effects on food supply. There is less decadal variablity in the small copepod (SC) biomass than large copepod (LC) biomass, but more variablity in SC than in LC at periods 2–4 years. In contrast to the large copepods, the biomass of small copepods was not related to global climate indices but with the local climate factors such as SST in the Kuroshio and variability in the Kuroshio flow path. Causes for the differences in the biomass trends between large and small copepods are discussed.
Copepod species diversity and climate variability in the tropical Atlantic Ocean
Authors: Piontkovski Sergey A. , Landry Michael R. 
Published: September 2003

AbstractA database synthesized from 19 oceanographic expeditions conducted by the former Soviet Union was used to analyse interannual patterns in copepod species diversity in the tropical Atlantic. Mesozooplankton was collected predominately in vertical hauls through the upper 100 m with Juday nets. The samples from 744 oceanographic stations were identified and enumerated to the species level. To assess species diversity, the Shannon diversity index was used. On the interdecadal scale, no statistically confirmed trend was found in species diversity change over the years sampled (1963–89). Multiple regression analysis indicated that interannual fluctuations of the South Atlantic High (pressure and latitude), the Azores High longitude and El Niño–Southern Oscillation (ENSO) index could explain 87% of species diversity fluctuations. Possible mechanisms that drive interannual fluctuations of species diversity are discussed.