Ocean mover's distance: using optimal transport for analysing oceanographic data

Remote sensing observations from satellites and global biogeochemical models have combined to revolutionize the study of ocean biogeochemical cycling, but comparing the two data streams to each other and across time remains challenging due to the strong spatial-temporal structuring of the ocean. Here, we show that the Wasserstein distance provides a powerful metric for harnessing these structured datasets for better marine ecosystem and climate predictions. The Wasserstein distance complements commonly used point-wise difference methods such as the root-mean-squared error, by quantifying differences in terms of spatial displacement in addition to magnitude. As a test case, we consider chlorophyll (a key indicator of phytoplankton biomass) in the northeast Pacific Ocean, obtained from model simulations, in situ measurements, and satellite observations. We focus on two main applications: (i) comparing model predictions with satellite observations, and (ii) temporal evolution of chlorophyll both seasonally and over longer time frames. The Wasserstein distance successfully isolates temporal and depth variability and quantifies shifts in biogeochemical province boundaries. It also exposes relevant temporal trends in satellite chlorophyll consistent with climate change predictions. Our study shows that optimal transport vectors underlying the Wasserstein distance provide a novel visualization tool for testing models and better understanding temporal dynamics in the ocean.

Egg incubation temperature influences the population-specific outmigration rate of juvenile brown trout Salmo trutta

The present experiment tested if temperature during embryogenesis and parental heritage affected the migratory behaviour of young brown trout Salmo trutta. Two parental forms were used, a freshwater resident form and an anadromous form, both from the same river system but geographically isolated since 1993-95. Four groups of young S. trutta were produced and reared from (a) freshwater resident parents spawning in a tributary to the River Imsa, Norway, (b) anadromous parents spawning in the main stem of the same river system, (c) resident male × anadromous female parents and (d) resident female × anadromous male parents. The eggs were incubated until first exogenous feeding in River Imsa water, either unheated or heated c. 2.7°C above ambient temperature. Thereafter, all fish experienced the same ambient river temperature until release. Groups were released below an impassable waterfall 900 m upstream of the mouth of the River Imsa, either as age-0 in October 2019 or as age-1 in May 2020. About 7.5% of the released fish moved downstream and were captured in a trap at the outlet. For any given body size, the proportion of warm incubated trout that moved downstream was greater than the proportion of cold incubated trout. It was also found that most emigrants of the October-released S. trutta were caught within a month of release. Also, most May-released S. trutta emigrated in October. The offspring of the freshwater resident parents emigrated to a larger extent than offspring of anadromous parents. Thus, the difference in emigration with regard to embryonic temperature was phenotypically plastic and may be associated with an epigenetic effect of the thermal conditions during early development. The effect of parental origin suggests there may be genetic divergence between the geographically isolated populations.

Differences in growth between offspring of anadromous and freshwater brown trout Salmo trutta

In this study, individual growth of juvenile offspring of anadromous and freshwater resident brown trout Salmo trutta and crosses between the two from the River Imsa, Norway, was estimated. The juveniles were incubated until hatching at two temperatures (±S.D.), either 4.4 ± 1.5°C or 7.1 ± 0.6°C. Growth rate was estimated for 22 days in August-September when the fish on average were c. 8 g in wet mass, and the estimates were standardized to 1 g fish dry mass. Offspring of anadromous S. trutta grew better at both 15 and 18°C than offspring of freshwater resident S. trutta or offspring of crosses between the two S. trutta types. This difference appears not to result from a maternal effect because anadromous S. trutta grew better than the hybrids with anadromous mothers. Instead, this appears to be an inherited difference between the anadromous and the freshwater resident fish lending support to the hypothesis that anadromous and freshwater resident S. trutta in this river differ in genetic expression. Egg incubation temperature of S. trutta appeared not to influence the later growth as reported earlier from the studies of Atlantic salmon Salmo salar.

Continuous outmigration and sequential encountering of environmental cues are important for successful homing of hatchery-reared, anadromous brown trout Salmo trutta

When rehabilitating and reintroducing trout Salmo trutta in rivers, it is a goal that as many as possible survive, home and form self-sustaining populations. Hatchery-reared, anadromous S. trutta have significant lower ability to return to the area where they were raised if (a) transported in a closed tank to sea and released 5 km from the River Imsa, relative to those that were (b) transported when swimming in a partly submerged tank with sea water run-through, while being slowly towed by a boat the same distance or (c) released at the outlet of the River Imsa. Thus, if deprived from environmental cues during part of the way, they lose their ability to home.

Body shape and fin size in juvenile Atlantic salmon (Salmo salar): effects of temperature during embryogenesis

Temperature during egg incubation and early development influences later life stages of fishes, potentially influencing survival. Throughout its distribution, Atlantic salmon (Salmo salar Linnaeus, 1758) have experienced population declines, and in view of ongoing global warming, we tested if temperature during the earliest developmental stages modified body shape and fin size when temperatures averaged 2.6 vs. 5.6 °C. This temperature difference simulates increases predicted in climate change scenarios. Based on previous studies, we hypothesized that salmon originating from eggs subjected to cold incubation temperatures would have slimmer bodies and larger pectoral and dorsal fins than salmon from eggs that experienced warmer temperatures. After hatching, the juveniles were raised for 1 year under identical temperatures, after which we measured their body shape and fin areas. We found no support for our hypothesis regarding body shape. Indeed, we found the opposite, with cold-incubated salmon having deeper bodies than warm-incubated salmon. For fin size, the pectoral fins of cold-incubated salmon were larger than for warm-incubated salmon as predicted, but there was no difference in dorsal fin size. These results suggest that global warming may lead to altered body shape and fin size, possibly affecting swimming performance, and thus raise questions about the ecological consequences of the changes.

Egg incubation temperature affects the timing of the Atlantic salmon Salmo salar homing migration

Here, we show that adult Atlantic salmon Salmo salar returned about 2 weeks later from the feeding areas in the North Atlantic Ocean to the Norwegian coast, through a phenotypically plastic mechanism, when they developed as embryos in c. 3°C warmer water than the regular incubation temperature. This finding has relevance to changes in migration timing caused by climate change and for cultivation and release of S. salar.

Neonatal intestinal colonization with extended-spectrum β-lactamase-producing Enterobacteriaceae-a 5-year follow-up study

OBJECTIVES

To analyse Klebsiella pneumoniae (KP) isolates from an outbreak of extended-spectrum β-lactamase (ESBL)-producing KP and Escherichia coli (EC) among infants admitted to neonatal intensive care units and to determine the duration of the intestinal colonization.

METHODS

We performed a prospective cohort study of intestinal ESBL-KP/ESBL-EC colonized neonates after a 5-month outbreak in two neonatal intensive care units. Whole genome sequencing, multilocus sequence typing, core genome multilocus sequence typing, pulsed-field electrophoresis and PCR for bla_CTX-M were performed on the first isolates. Stool cultures were performed every second month after discharge until 2 years after discharge and at 5 years of age. The last positive samples were analysed with pulsed-field gel electrophoresis and PCR for bla_CTX-M. The intestinal relative dominance of ESBL-producing Enterobacteriaceae was determined.

RESULTS

Thirteen of 17 patients colonized with ESBL-KP/ESBL-EC survived. Isolates from 16 of 17 patients were available for analysis and featured the same strain type of ESBL-KP: sequence type 101. The strain had capsule type K29 and harboured bla_CTX-M-15. The virulence genes irp1, irp2, iutA, kfu and mrk were detected in all isolates. The median length of colonization was 12.5 months (range, 5-68 months). After 2 years, two of 13 patients were carriers of ESBL-KP and one of 13 of ESBL-EC. At 5 years of age, one neonate was colonized with ESBL-EC. No infant experienced an ESBL-KP/EC-infection during follow-up.

CONCLUSIONS

Two years after discharge, almost one fourth of the study participants were ESBL/KP-EC carriers. ESBL-KP sequence type 101 persisted in two of 13 children for 23 to 26 months. One patient was colonized with ESBL-EC at age 5 years.

Mitigation of acidified salmon rivers - effects of liming on young brown trout Salmo trutta

In southern Norway, 22 acidified rivers supporting anadromous salmonids were mitigated with lime to improve water quality and restore fish populations. In 13 of these rivers, effects on Salmo trutta and Salmo salar densities were monitored over 10-12 years, grouped into age 0 and age ≥ 1 year fish. These rivers had a mean annual discharge of between 4·9 and 85·5 m³  s^-1 , and six of them were regulated for hydro-power production. Salmo salar were lost in six of these rivers prior to liming, and highly reduced in the remaining seven rivers. Post-liming, S. salar became re-established in all six rivers with lost populations, and recovered in the seven other rivers. Salmo trutta occurred in all 13 study rivers prior to liming. Despite the improved water quality, both age 0 and age ≥ 1 year S. trutta densities decreased as S. salar density increased, with an average reduction of >50% after 10 years of liming. For age 0 year S. trutta this effect was less strong in rivers where S. salar were present prior to liming. In contrast, densities of S. trutta increased in unlimed streams above the anadromous stretches in two of the rivers following improved water quality due to natural recovery. Density increases of both age 0 and age ≥ 1 year S. salar showed a positive effect of river discharge. The results suggest that the decline in S. trutta density after liming is related to interspecific resource competition due to the recovery of S. salar. Thus, improved water quality through liming may not only sustain susceptible species, but can have a negative effect on species that are more tolerant prior to the treatment, such as S. trutta.

Influences of migration phenology on survival are size-dependent in juvenile Atlantic salmon (Salmo salar)

Long-distance migratory species can reduce mortality risks by synchronizing the migration event and create confusion by swamping predators with high densities. To reduce confusion, predators are known to primarily select aberrant prey. We hypothesized that at the start of their sea sojourn, particularly small and large Atlantic salmon (Salmo salar L., 1758) would spread the risk by also migrating at other times of the year. Based on data from the Norwegian river Imsa between 1976 and 2015, we found that juveniles, 14–19 cm in total length, started their sea sojourn during a short period between late April and early June. However, more than 20% of fish 13 cm or shorter migrated downstream between October and March, whereas 55% of fish 20 cm or longer migrated downstream between July and September. The regular-sized, spring-migrating juveniles had 2–3 times higher survival at sea than similar-sized conspecifics migrating to sea at other times of the year. The survival at sea for smaller juveniles was not improved by migration in spring relative to winter, and the survival of the largest juveniles was similar in spring and summer. Thus, the migration phenology appears adapted to survival in a high-risk environment by changing the timing according to their sizes.

Socioeconomic factors' effect on return to work after first stroke

OBJECTIVE

The objective of this nationwide study was to analyze how functional status and socioeconomic status affect return to work (RTW) among younger patients with first-time stroke in a Sweden.

MATERIAL AND METHODS

This register-based cohort study included employed patients aged 25-55 with first-time stroke between 2008 and 2011 and primary outcome was RTW within 1 year after stroke. Data regarding functional status and employment status were retrieved from the Swedish Stroke Register, Riksstroke, and socioeconomic data (income, education, and country of birth) from Statistics Sweden.

RESULTS

We included 2539 patients who had answered the question on RTW, and 1880 (74.0%) had RTW within 12 months. Patients with low income (69.9% in lowest income group vs 79.9% in highest group, P<.001), patients born in countries outside the Nordic countries (Sweden 75.5%, Nordic countries 74.3%, European countries 61.7%, other countries 57.3%, P<.001), and the youngest patients (25-34, 63.1%; 35-44, 75.9%; 45-55, 74.3%; P=.008) were less likely to RTW. Pain, low mood, and answering the questionnaire with help were more common in low socioeconomic groups, and when adjusting for these variables, together with age and sex, income and country of birth were no longer independent predictors for RTW.

CONCLUSION

Patients with low socioeconomic status less often RTW 1 year after stroke.Impaired functional status after stroke is more common in patients with lower socioeconomic status and mediates socioeconomic differences in RTW. Improvement of functional status should be targeted to facilitate RTW among stroke patients with low socioeconomic status.

Gene flow from domesticated escapes alters the life history of wild Atlantic salmon

Interbreeding between domesticated and wild animals occurs in several species. This gene flow has long been anticipated to induce genetic changes in life-history traits of wild populations, thereby influencing population dynamics and viability. Here, we show that individuals with high levels of introgression (domesticated ancestry) have altered age and size at maturation in 62 wild Atlantic salmon Salmo salar populations, including seven ancestral populations to breeding lines of the domesticated salmon. This study documents widespread changes to life-history traits in wild animal populations following gene flow from selectively bred, domesticated conspecifics. The continued high abundance of escaped, domesticated Atlantic salmon thus threatens wild Atlantic salmon populations by inducing genetic changes in fitness-related traits. Our results represent key evidence and a timely warning concerning the potential ecological impacts of the globally increasing use of domesticated animals.

Trans-generational maternal effect: temperature influences egg size of the offspring in Atlantic salmon Salmo salar

Effect of increased temperature during egg maturation on the mass of single eggs produced by the offspring was investigated experimentally in Atlantic salmon Salmo salar. Mass of eggs produced by next-generation females was larger when their mothers experienced warmer water during the last two months of egg maturation, relative to those that experienced unheated river water. There was no similar trans-generational paternal effect on offspring egg mass.

Increased precision of growth data gained by reading multiple scales from each individual of Atlantic salmon (Salmo salar)

<p style="margin: 0cm 0cm 0pt; line-height: 200%;">The precision of growth estimates based on fish scales often remains uncertain because of withinindividual variation in scale size and scale patterns, and also due to measurement errors. Based on scale readings of Atlantic salmon, we show that errors decreased with number of times and number of scales read per fish. The annual number of scale circuli was not constant, but positively correlated with annual specific growth rates. Number of circuli deposited after the last winter correlated positively with sampling date. There was no significant relationship between mean inter-circuli distance and the total circuli number during the first and second year at sea. For growth estimation in scientific studies, we recommend the use of 4-5 scales per fish. Consideration should be given to both circuli number and inter-circuli distances when estimating growth rate instead of relying on inter-circuli distances only.</p>

Environmental change influences the life history of salmon Salmo salar in the North Atlantic Ocean

Annual mean total length (LT) of wild one-sea-winter (1SW) Atlantic salmon Salmo salar of the Norwegian River Imsa decreased from 63 to 54 cm with a corresponding decrease in condition factor (K) for cohorts migrating to sea from 1976 to 2010. The reduction in LT is associated with a 40% decline in mean individual mass, from 2 to 1·2 kg. Hatchery fish reared from parental fish of the same population exhibited similar changes from 1981 onwards. The decrease in LT correlated negatively with near-surface temperatures in the eastern Norwegian Sea, thought to be the main feeding area of the present stock. Furthermore, S. salar exhibited significant variations in the proportion of cohorts attaining maturity after only one winter in the ocean. The proportion of S. salar spawning as 1SW fish was lower both in the 1970s and after 2000 than in the 1980s and 1990s associated with a gradual decline in post-smolt growth and smaller amounts of reserve energy in the fish. In wild S. salar, there was a positive association between post-smolt growth and the sea survival back to the River Imsa for spawning. In addition, among smolt year-classes, there were significant positive correlations between wild and hatchery S. salar in LT, K and age at maturity. The present changes may be caused by ecosystem changes following the collapse and rebuilding of the pelagic fish abundance in the North Atlantic Ocean, a gradual decrease in zooplankton abundance and climate change with increasing surface temperature in the Norwegian Sea. Thus, the observed variation in the life-history traits of S. salar appears primarily associated with major changes in the pelagic food web in the ocean.

Extremely preterm infants who are small for gestational age have a high risk of early hypophosphatemia and hypokalemia

AIM

Electrolyte balances have not been sufficiently evaluated in extremely preterm infants after early parenteral nutrition. We investigated the risk of early hypophosphatemia and hypokalemia in extremely preterm infants born small for gestational age (SGA) who received nutrition as currently recommended.

METHODS

This prospective, observational cohort study included all consecutive extremely preterm infants born at 24-27 weeks who received high amino acids and lipid perfusion from birth. We evaluated the electrolyte levels of SGA infants and infants born appropriate for gestational age (AGA) during the first five days of life.

RESULTS

The 12 SGA infants had lower plasma potassium levels from Day One compared to the 36 AGA infants and were more likely to have hypokalemia (58% vs 17%, p = 0.001) and hypophosphatemia (40% vs 9%, p < 0.01) during the five-day observation period. After adjusting for perinatal factors, SGA remained significantly associated with hypophosphatemia (odds ratio 1.39, confidence intervals 1.07-1.81, p = 0.01).

CONCLUSION

Extremely preterm infants born SGA who were managed with currently recommended early parenteral nutrition had a high risk of early hypokalemia and hypophosphatemia. Potassium and phosphorus intakes should be set at sufficient levels from birth onwards, especially in SGA infants.

An Ultrahigh Precision, High-Frequency Dissolved Inorganic Carbon Analyzer Based on Dual Isotope Dilution and Cavity Ring-Down Spectroscopy

We present a novel method for continuous and automated shipboard measurements of dissolved inorganic carbon concentration ([DIC]) in surface water. The method is based on dual isotope dilution and cavity ring-down spectroscopy (DID-CRDS). In this method, seawater is continuously sampled and mixed with a flow of NaH(13)CO3 solution that is also enriched in deuterated water (the spike). The isotopic composition of CO2 (δ(13)C(spiked_sample)) derived from the DIC in the mixture, and the D/H ratio of the mixed water (δD(spiked_sample)), are measured by CRDS analyzers. The D/H of the water in the mixture allows accurate estimates of the mixing ratio of the sample and the spike. [DIC] of the sample is then calculated from the mixing ratio, [DI(13)C] of the spike, and δ(13)C(spiked_sample). In the laboratory, the precision of the method is <0.02% (±0.4 μmol kg(-1) when [DIC] = 2000 μmol kg(-1)). A shipboard test was conducted in the Delaware Bay and Estuary. For 2 min average [DIC], a precision of <0.03% was achieved. Measurements from the DID-CRDS showed good agreement with independent measurements of discrete samples using the well-established coulometric method (mean difference = -1.14 ± 1.68 μmol kg(-1)), and the nondispersive infrared(NDIR)-based methods (mean difference = -0.9 ± 4.73 μmol kg(-1)).

Sexual size dimorphism in anadromous brown trout Salmo trutta

Anadromous trout Salmo trutta exhibits sexual size dimorphism (SSD ); females were larger than males in populations where male mean total length (LT ) at maturity was below 49 cm and females were smaller than males when mean male LT was above 49 cm, the slope of the regression of female on male LT was 0·59. In streams with mean annual discharge below 41 m(3) s(-1) , flow added significantly to a model with SSD as the dependent variable and male mean LT at maturity as the first predictor variable. There was a slight increase in SSD with increasing latitude, which may result from an increase in male size with increasing latitude.

The growth hormone receptor exon 3-deleted/full-length polymorphism and response to growth hormone therapy in prepubertal idiopathic short children

OBJECTIVE

The primary aim of the study was to evaluate d3-GHR as a possible cause of increased GH sensitivity in children with delayed infancy-childhood transition (DICT). The secondary aim was to investigate the impact of the GHR exon 3 deleted/full-length (d3/fl) polymorphism on GH treatment response in prepubertal children classified as having idiopathic short stature (ISS).

DESIGN

Study subjects included 167 prepubescent longitudinally followed children classified as having ISS. Children were randomized to standard-dose GH treatment (33 μg kg(-1) day(-1)), to double-dose treatment (67 μg kg(-1) day(-1)), or to an untreated control group. Growth and metabolic outcome were evaluated at birth (n = 166), after one year of treatment (n = 59) and at adult height (n = 145). Genotyping of the GHR d3/fl polymorphism was performed using TaqMan SNP genotyping of tagSNP rs6873545.

RESULTS

Birth and early growth data did not reach the predetermined level of statistical significance for difference between genotypes. Growth and IGF-1 response after one year of GH treatment did not differ between genotypes. IGFBP-3SDS was higher in untreated d3-GHR carriers than in untreated fl/fl individuals, whereas there was insufficient evidence for higher IGFBP-3SDS in treated d3-GHR carriers. Genotype did not explain the growth response to treatment, and no differences in heightSDS, height gain, or difference in height to midparental heightSDS between genotype groups were found at adult height.

CONCLUSION

The common GHR d3/fl polymorphism is probably not a cause of DICT in children with ISS, and our results do not suggest that the d3-GHR genotype is associated with increased sensitivity to GH in children with ISS.

Early environment influences later performance in fishes

Conditions fish encounter during embryogenesis and early life history can leave lasting effects not only on morphology, but also on growth rate, life-history and behavioural traits. The ecology of offspring can be affected by conditions experienced by their parents and mother in particular. This review summarizes such early impacts and their ecological influences for a variety of teleost species, but with special reference to salmonids. Growth and adult body size, sex ratio, egg size, lifespan and tendency to migrate can all be affected by early influences. Mechanisms behind such phenotypically plastic impacts are not well known, but epigenetic change appears to be one central mechanism. The thermal regime during development and incubation is particularly important, but also early food consumption and intraspecific density can all be responsible for later life-history variation. For behavioural traits, early experiences with effects on brain, sensory development and cognition appear essential. This may also influence boldness and other social behaviours such as mate choice. At the end of the review, several issues and questions for future studies are given.

Time and size at seaward migration influence the sea survival of Salmo salar

Whether time of seaward migration of young Atlantic salmon Salmo salar influences their subsequent survival and growth was investigated in the River Imsa, south-western Norway. Salmo salar were tagged when moving downstream through a trap near the outlet between 1976 and 2010 and recaptured on their adult return. Most descended as smolts in April and May, but some descended during the other months of the year. Annual variation in timing of the smolt migration was significantly correlated with variation in water temperature during spring. Mean total body length of the descending S. salar varied with month of seaward migration. The sea survival of S. salar emigrating from the River Imsa between January and May was 2·8 times higher than for those descending between June and December. The sea survival of the various cohorts decreased with increasing river temperature in April to May, prior to the smolt migration, and decreasing day number when the smolts moved to sea. The size of smolts descending the river between April and May did not affect the survival at sea as much as it affected the survival of migrants descending in any other month of the year. The majority of the downstream migrating S. salar were 2 years old, but proportionally, more 1 year olds moved downstream in the autumn than in the rest of the year. Mean duration between downstream migration of the young and the return migration of the grilse was shortest (12·7 months) for those descending in July and August and longest for those descending in October (21 months). Mean monthly specific growth rate was highest for those migrating downstream between May and July and lowest for those emigrating in September. Based on the present results, it was hypothesized that S. salar emigrating between April and August migrated directly out into the ocean, while those that emigrated between October and March stayed in the estuary until the subsequent spring.

Penile size in healthy Nigerian newborns: country-based reference values and international comparisons

AIM

To establish normal reference values for penile size in Nigerian newborn boys and to compare those values with standards from other populations.

METHODS

A total number of 261 healthy newborn boys delivered at gestational ages of 28 weeks or more were enrolled in the study. Penile lengths and widths were measured within 72 h of birth.

RESULTS

The mean (±SD) penile length in the 261 Nigerian males studied was 3.4 ± 0.48 cm, while the mean mid-shaft diameter was 1.2 ± 0.14 cm. Compared with data from other populations, Nigerian newborn boys had similar penile sizes to those reported for US Caucasian boys (mean 3.4 cm), but significantly greater penile sizes than those reported for boys from China and Hong Kong (mean 3.0 and 3.1 cm, respectively; both p < 0.001). There was a slight, but significant, difference in size between Nigerian and Malaysian boys, with Malaysian boys having greater penile sizes (mean 3.5 cm; p < 0.05).

CONCLUSION

A Nigerian newborn with a penile length of <2.39 cm can be considered to have a micropenis.

Basin-scale phenology and effects of climate variability on global timing of initial seaward migration of Atlantic salmon (Salmo salar)

Migrations between different habitats are key events in the lives of many organisms. Such movements involve annually recurring travel over long distances usually triggered by seasonal changes in the environment. Often, the migration is associated with travel to or from reproduction areas to regions of growth. Young anadromous Atlantic salmon (Salmo salar) emigrate from freshwater nursery areas during spring and early summer to feed and grow in the North Atlantic Ocean. The transition from the freshwater ('parr') stage to the migratory stage where they descend streams and enter salt water ('smolt') is characterized by morphological, physiological and behavioural changes where the timing of this parr-smolt transition is cued by photoperiod and water temperature. Environmental conditions in the freshwater habitat control the downstream migration and contribute to within- and among-river variation in migratory timing. Moreover, the timing of the freshwater emigration has likely evolved to meet environmental conditions in the ocean as these affect growth and survival of the post-smolts. Using generalized additive mixed-effects modelling, we analysed spatio-temporal variations in the dates of downstream smolt migration in 67 rivers throughout the North Atlantic during the last five decades and found that migrations were earlier in populations in the east than the west. After accounting for this spatial effect, the initiation of the downstream migration among rivers was positively associated with freshwater temperatures, up to about 10 °C and levelling off at higher values, and with sea-surface temperatures. Earlier migration occurred when river discharge levels were low but increasing. On average, the initiation of the smolt seaward migration has occurred 2.5 days earlier per decade throughout the basin of the North Atlantic. This shift in phenology matches changes in air, river, and ocean temperatures, suggesting that Atlantic salmon emigration is responding to the current global climate changes.

Growth in prepubertal Nigerian children is highly dependent on socio-economic status

AIM

To relate height, weight and body mass index (BMI) of prepubertal children in Sagamu, Nigeria, to parental socio-economic class (SEC).

METHODS

Cross-sectional study of 1606 children aged 5-11 years from eight public and eight private primary schools. Height, weight and BMI from 1557 prepubertal children were standardized using two references: US-CDC birth cohorts 1929-1974 and Swedish birth cohort 1974.

RESULTS

Children in private schools were taller and heavier than those in public schools (p < 0.0001). Most children (73.2%) belonged to lower SEC, 17.6% to middle and 9.2% to upper. HeightSDS , weightSDS and BMISDS increased with increasing parental SEC. Upper SEC children were taller and heavier with higher BMIs than those from lower SEC (p < 0.0001). HeightSDS , weightSDS and BMISDS were below '0' in all SEC and gender groups (all p < 0.002). Younger children were taller and heavier than the older (p < 0.0001).

CONCLUSION

Fathers/mothers with higher education/occupation had taller and heavier children with higher BMI than other groups. Children in private schools were taller and heavier than children in public schools. Disparities in parental SEC still constrain optimal child growth in Nigeria: whereas height and weight of children of upper SEC were close to the US-CDC29-74 reference mean, they were still below Swedish74 reference mean representing more optimal growth.

An experimental study of the multiple effects of brown trout Salmo trutta on the bioenergetics of two Arctic charr Salvelinus alpinus morphs

This study investigated the importance of competition with brown trout Salmo trutta as a driver of the morphological and behavioural divergence of two morphs of Arctic charr Salvelinus alpinus. The morphs originated from two lakes differing in absence or presence of the competitor. The bioenergetics and behaviour of S. alpinus were quantified in replicate experimental enclosures (mean volume: 150 m(3)) stocked with 15 S. alpinus of one morph or the other and in the absence or presence of nine S. trutta. The presence of S. trutta decreased growth rate, affected food consumption and increased activity costs in S. alpinus, but provided little support for the hypothesis that competition with S. trutta is a major driver of the divergence of the two S. alpinus morphs. Both morphs responded similarly in terms of mean growth and consumption rates per enclosure, but the association between individual morphology and growth rate reversed between allopatric and sympatric enclosures. While the activity patterns of the two morphs were unaffected by the presence of S. trutta, their swimming speed and activity rate differed. Since the profound differences in the structure of the physical habitat of the source lakes provided a more likely explanation for the difference observed among these two morphs than interspecific competition, it is hypothesized that physical habitat may sometimes be a significant driving force of the phenotypic divergence.

Effects of temperature and food quality on age and size at maturity in ectotherms: an experimental test with Atlantic salmon

The reaction norm between growth rate, age and size at maturity in ectotherms is widely debated in ecological literature. It has been proposed that the effect depends on whether growth is affected by food quality or temperature (called the Berrigan-Charnov puzzle). The present experiment tested this for Atlantic salmon (Salmo salar). We enhanced growth rates by increasing temperature and ratio of lipids to proteins in the food for groups of Atlantic salmon. Both treatments gave higher percentages of early mature and therefore smaller adults in contrast to the proposed Berrigan-Charnov puzzle. There was a difference between sexes in that males could attain maturity 1 year younger than females when reared under similar environmental conditions. Males that matured during the first year in sea water were smaller than similar aged immature males. The probability of that Atlantic salmon attained maturity for the first time during their second year in sea increased with growth rate during the preceding winter and if fed a high-lipid diet. Increased summer temperature exhibited no additional effect. Similar aged fish reared at elevated temperature and fed high-lipid diet attained maturity at a larger body mass and exhibited higher mass-length-ratios than those reared at natural temperature and fed a low-lipid diet, indicating that structural growth has priority over lipid deposits. Increased growth rate before the onset of maturation, whether this is owing to enhanced lipid content in food or increased water temperature, decreased age and therefore size at maturity. Enhanced lipid relative to protein content in food, but not temperature, had an additive positive effect on early maturation probability, likely due to increased amounts of reserve energy. These results may be general for ectotherm organisms.

Preterm appropriate for gestational age infants: size at birth explains subsequent growth

AIM

 The aim was to evaluate growth and breastfeeding up to 18 months corrected age (CA) among preterm appropriate for gestational age (AGA) infants whose mothers initiated breastfeeding during the infants' hospital stay.

METHODS

 One hundred and twenty-seven preterm AGA infants with a median birth weight of 2320 (769-3250) g and gestational age 34.29 (25.00-35.86) weeks were evaluated up to a CA of 18 months. A retrospective, descriptive and comparative design was used. Data were obtained by chart review of hospital medical records and a questionnaire completed by the mothers.

RESULTS

The changes in standard deviation scores (SDS) during the infants' hospital stay were -0.9 for weight, -0.3 for length and -0.5 for head circumference (HC). Infants with higher SDS at birth showed more negative changes from birth to discharge. Median increments in SDS from discharge to a CA of 2 months were as high as, or higher than, the loss from birth to discharge.

CONCLUSION

 Preterm AGA infants with higher SDS for weight, length and HC at birth are at higher risk of inadequate growth during their hospital stay.

Can the TW3 bone age determination method provide additional criteria for growth hormone treatment in adopted girls with early puberty? A comparison of the Tanner-Whitehouse 3 method with the Greulich-Pyle and the Tanner-Whitehouse 2 methods

BACKGROUND/AIMS

Gonadotropin-releasing hormone analogues (GnRHa) are the accepted treatment of idiopathic central precocious puberty. As it has been found that growth velocity may be decreased with GnRHa treatment, clinical trials with GnRHa combined with growth hormone (GH) have been carried out. In a recent study 46 adopted girls with early or precocious puberty were randomly assigned to treatment with either GnRHa or GnRHa combined with GH, and followed to final height (FH). It was found that FH was significantly higher in the combined treatment group, 158.9 compared with 155.8 cm in the GnRHa treated group. In order to select the patients who could benefit from added GH, predictions of FH at the start of treatment according to the methods of bone age determination of Greulich-Pyle (GP) and Tanner-Whitehouse 2 (TW2) were compared. It was found that the GP method was the most useful method for patient selection. Recently, a revision of the Tanner-Whitehouse method, named Tanner-Whitehouse 3 (TW3), has been developed. The present study examined the usefulness of the TW3 method in selecting suitable patients for combined treatment.

METHOD

The TW3 method bone age determinations of the 46 girls were compared to the GP and TW2 method determinations, using the differences between actual FH and predicted adult height (PAH). Beside accuracy of prediction of FH, the criteria of efficiency of selection and replicability were applied in the comparison.

RESULTS

We found that the GP method, also when compared to the TW3 method, gave the most accurate prediction of the FH on only GnRHa treatment. This gives the best ground for selection of patients who can benefit from combined treatment. The GP method was also the most efficient in selecting patients, i.e., it could select the least number of patients that needed the combined treatment. The only drawback of the GP method was that it requires an experienced pediatric radiologist. Automated methods are being developed and may soon facilitate the use of the GP method for those less experienced. The FH after combined treatment could be predicted with an equation including PAH GP as well as PAH TW3 as variables.

CONCLUSION

The GP method remains the most useful method for selection of those patients who will benefit most from the addition of GH to GnRHa in the treatment of idiopathic central precocious or early puberty. FH prediction after combined treatment requires PAH GP as well as PAH TW3.

Late effects of early growth hormone treatment in Down syndrome

OBJECTIVE

Down syndrome (DS) is associated with short stature and psychomotor delay. We have previously shown that growth hormone (GH) treatment during infancy and childhood normalizes growth velocity and improves fine motor skill performance in DS. The aim of this study was to investigate late effects of early GH treatment on growth and psychomotor development in the DS subjects from the previous trial.

DESIGN

Twelve of 15 adolescents with DS (3 F) from the GH group and 10 of 15 controls (5 F) participated in this follow-up study. Fifteen other subjects with DS (6 F) were included as controls in anthropometric analyses. Cognitive function was assessed with the Leiter International Performance Scale-Revised (Leiter-R) and selected subtests of the Wechsler Intelligence Scale for Children, Third edition (WISC-III). The Bruininks-Oseretsky Test of Motor Proficiency, Second edition (BOT-2), was used to assess general motor ability.

RESULTS

Although early GH treatment had no effect on final height, the treated subjects had a greater head circumference standard deviation score (SDS) than the controls (-1.6 SDS vs. -2.2 SDS). The adolescents previously treated with GH had scores above those of the controls in all subtests of Leiter-R and WISC-III, but no difference in Brief IQ-score was seen between the groups. The age-adjusted motor performance of all subjects was below -2 SD, but the GH-treated subjects performed better than the controls in all but one subtest.

CONCLUSION

The combined finding of a greater head circumference SDS and better psychomotor performance indicates that DS subjects may benefit from early GH treatment.

Health Related Quality of Life (HRQoL) in Swedish Relapse Free Breast Cancer Patients. A Study of EQ5D and TTO in a Patient Advocacy Population

Health Related Quality of life (HRQoL) factors are central in all cancer therapy. We have examined two HRQoL instruments, EQ5D and TTO in women treated for breast cancer and free of relapse.The participants were all members Swedish breast cancer advocacy group BRO. The aim of this study was to evaluate HRQoL in relation to age, time of diagnosis and compare this with healthy Swedish females (HF) of the same age (Burström K et al 2006).MethodsEQ-5D is a generic health-related quality of life (HRQoL) instrument/questionnaire that is used for economic evaluations of health interventions. The EQ-5D measures HRQoL in five dimensions and three levels of response, and correlate with disease specific quality of life instruments like EORTC QLQ-C30. Using population derived weights, EQ5D responses are translated to a global index between 0 (death) and 1 (full health).Time-Trade-Off (TTO) is used in health economics to determine the quality of life by trading improved quality of life for reductions in survival time. The respondent can choose to live 10 or 20 years in current health state or choose to give up some life years to live for a shorter period in full health. The number of years she/he is willing to give up to gain full health is translated into an index between 0 (willing to give up all remaining life time) and 1 (not willing to give up any remaining life time).ResultsWe sent out these quality of life instruments to members of BRO. A total of 4900 (52%) responded out of which 4027 were free of relapse. Respondents had a mean age of 62.1 years. Tumor and treatment characteristics reflect the prevalent Swedish breast cancer population.EQ5D and TTO, mean (SE) in HF and breast cancer patients (BC) in relation to age.EQ5D&lt;40 y40-49 y50-59 y60-69 y70-79 y&gt;80 yHF0.859 (0.011)0.858 (0.012)0.833 (0.014)0.784 (0.017)0.792 (0.019)0.740 (0.033)BC0.759 (0.050)0.755 (0.050)0.804 (0.038)0.839 (0.035)0.852 (0.031)0.822 (0.038)TTO      HF0.944 (0.009)0.944 (0.009)0.925 (0.010)0.894 (0.015)0.888 (0.017)0.673 (0.040)BC0.860 (0.037)0.883 (0.036)0.894 (0.036)0.909 (0.028)0.859 (0.046)0.769 (0.086) Mean EQ5D and TTO (SE) in relation to time since primary diagnosis and age (y) in BC patientsEQ5D&lt; 1 y1-3 y3-5 y&gt; 5 y&lt; 40 y0.714 (0.034)0.762 (0.043)0.703 (0.114)0.847 (0.019)40-49 y0.731 (0.043)0.734 (0.051)0.735 (0.060)0.800 (0.043)50-59 y0.779 (0.045)0.781 (0.035)0.789 (0.047)0.825 (0.035)60-69 y0.798 (0.048 )0.823 (0.034)0.837 (0.030)0.846 (0.036)70-79 y0.828 (0.020)0.846 (0.036)0.805 (0.056)0.860 (0.027)≥ 80 y-0.875 (0.021)0.662 (0.088)0.828 (0.036)TTO    &lt; 40 y0.839 (0.028)0.855 (0.040)0.814 (0.050)0.945 (0.025)40-49 y0.884 (0.021)0.862 (0.040)0.894 (0.035)0.898 (0.035)50-59 y0.896 (0.028)0.897 ( 0.032)0.876 (0.041)0.901 (0.035)60-69 y0.922 (0.021)0.902 (0.029)0.911 (0.027)0.909 (0.028)70-79    ≥ 80 y-0.850 (0.078)0.636 (0.086)0.771 (0.087) Conclusions:The results of this study indicate that older (&gt;60y) women with BC have better health status (measured by EQ5D and TTO), than healthy females (HF). Younger women (&lt;60y) with BC have lower health status than HF, but it increases with time from diagnosis.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5047.

A review of the likely effects of climate change on anadromous Atlantic salmon Salmo salar and brown trout Salmo trutta, with particular reference to water temperature and flow

The present paper reviews the effects of water temperature and flow on migrations, embryonic development, hatching, emergence, growth and life-history traits in light of the ongoing climate change with emphasis on anadromous Atlantic salmon Salmo salar and brown trout Salmo trutta. The expected climate change in the Atlantic is for milder and wetter winters, with more precipitation falling as rain and less as snow, decrease in ice-covered periods and frequent periods with extreme weather. Overall, thermal limits for salmonids are species specific. Scope for activity and growth and optimal temperature for growth increase with temperature to an optimal point before constrain by the oxygen content of the water. The optimal temperature for growth decreases with increasing fish size and varies little among populations within species, whereas the growth efficiency may be locally adapted to the temperature conditions of the home stream during the growth season. Indirectly, temperature influences age and size at smolting through its effect on growth. Time of spawning, egg hatching and emergence of the larvae vary with temperature and selective effects on time of first feeding. Traits such as age at first maturity, longevity and fecundity decrease with increasing temperature whilst egg size increases with temperature. Water flow influences the accessibility of rivers for returning adults and speed of both upstream and downstream migration. Extremes in water flow and temperature can decrease recruitment and survival. There is reason to expect a northward movement of the thermal niche of anadromous salmonids with decreased production and population extinction in the southern part of the distribution areas, migrations earlier in the season, later spawning, younger age at smolting and sexual maturity and increased disease susceptibility and mortality. Future research challenges are summarized at the end of the paper.

From isolated GH deficiency to multiple pituitary hormone deficiency: an evolving continuum - a KIMS analysis

OBJECTIVE

To describe baseline clinical presentation, treatment effects and evolution of isolated GH deficiency (IGHD) to multiple pituitary hormone deficiency (MPHD) in adult-onset (AO) GHD.

DESIGN

Observational prospective study.

METHODS

Baseline characteristics were recorded in 4110 patients with organic AO-GHD, who were GH naïve prior to entry into the Pfizer International Metabolic Database (KIMS; 283 (7%) IGHD, 3827 MPHD). The effect of GH replacement after 2 years was assessed in those with available follow-up data (133 IGHD, 2207 MPHD), and development of new deficiencies in those with available data on concomitant medication (165 IGHD, 3006 MPHD).

RESULTS

IGHD and MPHD patients had similar baseline clinical presentation, and both groups responded similarly to 2 years of GH therapy, with favourable changes in lipid profile and improved quality of life. New deficiencies were observed in 35% of IGHD patients, which was similar to MPHD patients with one additional deficit other than GH. New deficiencies most often presented within the first year but were observed up to 6 years after GH commencement. Conversion of IGHD into MPHD was not predicted by aetiology, baseline characteristics, surgery or radiotherapy, whereas in MPHD additional deficits were predicted by age (P<0.001) and pituitary disease duration (P<0.01).

CONCLUSION

Both AO-IGHD and -MPHD patients have similar baseline clinical presentation and respond equally well to 2 years of GH replacement. Hypopituitarism in adults seems to be a dynamic condition where new deficiencies can appear years after the initial diagnosis, and careful endocrine follow-up of all hypopituitary patients, including those with IGHD, is warranted.

Abnormal cold perception in the lower limbs: a sensitive indicator for detection of polyneuropathy in patients with type 1 diabetes mellitus

Diabetic peripheral neuropathy differs in type 1 and type 2 diabetes. The aim of this study was to evaluate how signs and symptoms of neuropathy correlated with defects in motor and sensory nerve conduction velocity (MCV and SCV) and sensory perception thresholds in patients with type 1 diabetes. MCV and SCV in peroneal and sural nerves and vibratory, warm and cold perception thresholds (VPT, WPT, CPT) were evaluated in the lower limbs of 127 patients (42+/-7.9 years old, duration of diabetes, 16+/-11 years and HbA1c, 7.7+/-1.4%). The results were compared with clinical findings (neuropathy impairment assessment, NIA) and sensory symptoms (neurological symptom assessment, NSA). Sensory symptoms were present in 24% of patients, 91% had at least one abnormal finding in the neurological examination and 84% had abnormal nerve conduction. The greatest deviation from normal was observed for CPT on the dorsum of the foot and peroneal MCV. NIA and NSA correlated with all electrophysiological measurements in the foot and big toe. It is concluded that clinical findings correlate well with electrophysiological abnormalities in patients with type 1 diabetic neuropathy. An elevated CPT for the foot was the most pronounced sensory defect.