Maturation Trends Research Articles

Reactivity and sleep in infants: a longitudinal objective assessment.

Sleep patterns and temperament in the first year of life are closely related. However, research utilizing objective, rather than subjective measurements of sleep and temperament is scarce and results are inconsistent. In addition, a relative lack of longitudinal data prevents inference of causality between the two constructs. In this study, infant sleep was objectively assessed among 95 infants at 3, 6, and 12 months-of-age with an actigraph in the home setting. Reactivity to sound, light, and touch, a specific aspect of temperament, was behaviorally assessed at 3 and 6 months, both during sleep (at home) and during waking (at the laboratory). Expected maturational trends were recorded in sleep, with a temporal increase in sleep efficiency and percent of motionless sleep. Quadratic (i.e., inverse U shape) relations were found, especially among girls, when predicting change in sleep by reactivity thresholds, suggesting that both hyposensitive and hypersensitive infants are at risk for poor sleep quality. These are the first research findings suggesting that low reactivity in infancy might be associated with compromised sleep quality. The observed nonlinear effects may account for null or inconsistent results in previous studies that explored only linear associations between temperament and sleep. Future studies should address both extremes of the temperament continuum when exploring relations with sleep patterns.

Probabilistic maturation reaction norm trends reveal decreased size and age at maturation in an intensively harvested stock of pikeperch Sander lucioperca

Abstract Reports of fishing-induced evolution in the maturation schedules of commercially exploited marine fishes are numerous and are alarming. Here, we analysed the probabilistic maturation reaction norms for a freshwater fish species, the pikeperch ( Sander lucioperca ), to assess whether the maturation patterns of cohorts 1993–2006 responded to intensive coastal commercial and recreational fishing in the Archipelago Sea area of the Baltic Sea. Lp 50 values estimated using individual data from catch samples revealed that maturation had shifted towards an earlier age and smaller size. Lengths-at-age showed variation, but no linear trends, whereas the condition factor decreased for most of the age groups. Cross-correlation analysis of Lp 50 values with variables describing stock size (potential social effects on maturation) and water temperature revealed no obvious growth-independent effects on the maturation trends. This suggests that fishing, in line with the life-history theory, was the most important driving factor favouring early maturation. These results suggest that fishing-induced shifts in the maturation patterns of fish are nearly ubiquitous and not limited to commercially harvested marine species. This calls for increased awareness of fishing-induced life-history changes also in coastal and inland fisheries management.

Geologic evolution of the Iraqi Zagros, and its influence on the distribution of hydrocarbons in the Kurdistan region

Whereas the vast majority of discovered hydrocarbon reserves in Iraq reside in Cretaceous and Cenozoic reservoirs, numerous oil and gas fields have been discovered recently in deeper Jurassic and Triassic reservoirs in the Kurdistan region of Iraq. This study presents a Middle–Upper Jurassic thermal maturity map for the Kurdistan region of Iraq and demonstrates that regional first-order trends in Jurassic source rock maturity show a close correlation to the spatial distribution of oil gravities within the overlying Jurassic (and Cretaceous) reservoirs. This distribution is consistent with compartmentalization of the active source rock kitchens due to Zagros folding, resulting in relatively short-distance migration and charge of the anticlinal structures from the adjacent synclinal lows. The thermal maturity map confirms relatively low maturity over the Mosul high, where the Cretaceous and Cenozoic section overlying the source rock interval is relatively thin, and increasing maturity to the southeast as the thickness of the Cenozoic foredeep sediments increases toward the depocenter located in the southeastern Iraqi Zagros and the adjacent Iranian Zagros. The correlative trend in oil gravities is exemplified by the recent Jurassic discoveries: low to medium gravity oils (14–27° API) in Shaikan and Atrush to the northwest, light oil (39–47° API) in Mirawa and Bina Bawi, and gas condensate (55° API) in Miran West to the southeast. Understanding thermal maturity patterns and hydrocarbon fluid-type distributions will help to guide risk assessment for remaining prospectivity and future exploration drilling within the Kurdistan region of Iraq.

Source, depositional environment and maturity levels of some crude oils in southwest Niger Delta, Nigeria

A suite of crude oil samples, that had not been previously characterized geochemically, was collected from two oil fields in the southwest Niger Delta Nigeria. The saturate biomarkers were used to evaluate geochemical characteristics such as depositional environments, sources of organic matter and extent of biodegradation using gas chromatography–flame ionization detector and gas chromatography–mass spectrometry. Distribution of n-alkanes (Pr/Ph, and isoprenoide/n-alkanes ratios), the abundance of hopanes, oleanane skeleton and C27–C29 steranes in the oils indicate that they were formed from mixed sources (marine and terrestrial kerogen) deposited in an oxic paleoenvironment with no particular maturity trend. These parameters also permit the source grouping of the oils into two families.

Organic Facies Characteristics of the Triassic Ispartaçay Formation, Antalya Nappes, Western Taurus, Turkey

In the Antalya Nappes (SW Turkey), the Triassic Ispartaçay Formation consists of radioaria, chert, turbiditic limestone and sandstone. Detailed data from thick Triassic sediments (Ispartaçay Formation) made it possible to construct an organic facies framework using different zonation. Organic matter is composed predominantly of woody material, with a minor contribution of planty and woody material. Kerogen in the deposits is type III, as indicated by organic petrographic observations and Rock-Eval data. Total organic carbon (TOC) values are generally between 0.16 and 1.36%, but reach 5.24% in the formation. Tmax values vary between 331 and 602°C, confirming the increase in maturation trends indicated by vitrinite reflectance data. Organic facies type D was identified in the investigated units. Organic facies D is related to sandstone and limestone litofacies. This facies is characterized by average values of HI around 18 (equivalent to type III kerogen), TOC around 0.85%, and an average of S2 of 0.19mg HC/g of rock. The organic matter is highly oxidized, decomposed and reworked. Organic facies D is no generative.

Reprint of “Organic petrology of the Aptian-age section in the downdip Mississippi Interior Salt Basin, Mississippi, USA: Observations and preliminary implications for thermal maturation history”

This study identifies a thermal maturity anomaly within the downdip Mississippi Interior Salt Basin (MISB) of southern Mississippi, USA, through examination of bitumen reflectance data from Aptian-age strata (Sligo Formation, Pine Island Shale, James Limestone, and Rodessa Formation). U.S. Geological Survey (USGS) reconnaissance investigations conducted in 2011–2012 examined Aptian-age thermal maturity trends across the onshore northern Gulf of Mexico region and indicated that the section in the downdip MISB is approaching the wet gas/condensate window (Ro ~1.2%). A focused study in 2012–2013 used 6 whole core, one sidewall core, and 49 high-graded cutting samples (depth range of 13,000–16,500ft [3962.4–5029.2m] below surface) collected from 15 downdip MISB wells for mineralogy, fluid inclusion, organic geochemistry, and organic petrographic analysis. Based on native solid bitumen reflectance (Ro generally >0.8%; interpreted to be post-oil indigenous bitumens matured in situ), Ro values increase regionally across the MISB from the southeast to the northwest. Thermal maturity in the eastern half of the basin (Ro range 1.0 to 1.25%) appears to be related to present-day burial depth and shows a gradual increase with respect to depth. To the west, thermal maturity continues to increase even as the Aptian section shallows structurally on the Adams County High (Ro range 1.4 to >1.8%). After evaluating the possible thermal agents responsible for increasing maturity at shallower depths (i.e., igneous activity, proximity to salt, variations in regional heat flux, and uplift), we tentatively propose that either greater paleoheat flow or deeper burial coupled with uplift in the western part of the MISB could be responsible for the thermal maturity anomaly. Further research and additional data are needed to determine the cause(s) of the thermal anomaly.

Secular trends of growth and pubertal maturation of school children in Southern Thailand

Background: In Thailand, studies of growth date back to 1975, but there have been no studies examining any trends in increasing/decreasing growth.Aim: To determine if there have been any secular trends of increasing/decreasing growth and/or ages at puberty in Thai children.Methods: In 2012, a cross-sectional study of growth was conducted in 3460 children. The median heights and weights and the ages of pubertal maturation were compared with previous studies. Correlations between the secular trends and the health statistics indicators were calculated.Results: From 1975–2012, the median final height of boys and girls had increased by 1.32 and 0.86 cm/decade and weight by 2.49 and 1.76 kg/decade, respectively. In girls, the age at thelarche and menarche had declined by 0.39 and 0.12 years/decade, respectively. In boys, the age at testicular enlargement Tanner II had declined by 0.15 years/decade. Increased physical growth was positively correlated to life expectancy, per capita income and prevalence of overweight/obesity was negatively correlated to prevalence of malnutrition and under-five mortality rate.Conclusion: The positive secular trend towards an increase in growth and a decline in the age at onset of puberty of Thai children is correlated with improvements in overall living conditions in Thailand.

Organic petrology of the Aptian-age section in the downdip Mississippi Interior Salt Basin, Mississippi, USA: Observations and preliminary implications for thermal maturation history

This study identifies a thermal maturity anomaly within the downdip Mississippi Interior Salt Basin (MISB) of southern Mississippi, USA, through examination of bitumen reflectance data from Aptian-age strata (Sligo Formation, Pine Island Shale, James Limestone, and Rodessa Formation). U.S. Geological Survey (USGS) reconnaissance investigations conducted in 2011–2012 examined Aptian-age thermal maturity trends across the onshore northern Gulf of Mexico region and indicated that the section in the downdip MISB is approaching the wet gas/condensate window (Ro ~1.2%). A focused study in 2012–2013 used 6 whole core, one sidewall core, and 49 high-graded cutting samples (depth range of 13,000–16,500ft [3962.4–5029.2m] below surface) collected from 15 downdip MISB wells for mineralogy, fluid inclusion, organic geochemistry, and organic petrographic analysis. Based on native solid bitumen reflectance (Ro generally >0.8%; interpreted to be post-oil indigenous bitumens matured in situ), Ro values increase regionally across the MISB from the southeast to the northwest. Thermal maturity in the eastern half of the basin (Ro range 1.0 to 1.25%) appears to be related to present-day burial depth and shows a gradual increase with respect to depth. To the west, thermal maturity continues to increase even as the Aptian section shallows structurally on the Adams County High (Ro range 1.4 to >1.8%). After evaluating the possible thermal agents responsible for increasing maturity at shallower depths (i.e., igneous activity, proximity to salt, variations in regional heat flux, and uplift), we tentatively propose that either greater paleoheat flow or deeper burial coupled with uplift in the western part of the MISB could be responsible for the thermal maturity anomaly. Further research and additional data are needed to determine the cause(s) of the thermal anomaly.

A new human IgG avidity test, using mixtures of recombinant antigens (rROP1, rSAG2, rGRA6), for the diagnosis of difficult-to-identify phases of toxoplasmosis

The preliminary diagnostic utility of two mixtures of Toxoplasma gondii recombinant antigens (rROP1+rSAG2 and rROP1+rGRA6) in IgG ELISA and IgG avidity test has been evaluated. A total of 173 serum samples from patients with toxoplasmosis and seronegative people were examined. The sensitivity of IgG ELISA for rROP1+rSAG2 and rROP1+rGRA6 was 91.1% and 76.7%, respectively, while the reactivity for sera from patients where acute toxoplasmosis was suspected was higher, at 100% and 95.4%, respectively, than for people with chronic infection, at 88.2% and 70.6%. In this study a different trend in avidity maturation of IgG antibodies for two mixtures of proteins in comparison with native antigen was observed. The results suggest that a new IgG avidity test using the mixtures of recombinant antigens may be useful for the diagnosis of difficult-to-identify phases of toxoplasmosis. For this reason, selected mixtures after the additional tests on groups of sera with well-defined dates of infection could be used as a better alternative to the native antigens of the parasite in the serodiagnosis of human T. gondii infection.

Temporal trends in age and size at maturation of four North Sea gadid species: cod, haddock, whiting and Norway pout

Younger ages and smaller sizes at maturation have been observed in commercial fish stocks over the last century. We establish that age and length at 50% proportion mature (i.e. the proportion of mature individuals in a population or the probability that an individual is mature) decreased from the 1970s to the 2000s in North Sea cod Gadus morhua, haddock Melanogrammus aeglefinus and whiting Merlangius merlangus, but not in Norway pout Trisopterus esmarkii. The potential contributions of demography, phenotypic plasticity and evolution to these trends were assessed. First, maturation trends were extricated from demographic effects and growth-dependent plasticity by estimating probabilistic maturation reaction norms (PMRNs). PMRN midpoints have significantly shifted downwards at most ages for cod, haddock and whiting, but not for Norway pout. Second, increased temperature and food abundance, loosened trophic competition and relaxed social pressure may also trigger growth-independent plasticity in maturation. Principal component regression of PMRN midpoints on annual estimates of relevant environmental vari- ables exhibiting a temporal trend suggest that, despite some evidence of environmental effects, PMRN trends were mostly independent of growth-independent plasticity in haddock, whiting and male cod, but not in female cod. According to these findings, evolution of maturation, potentially in response to fishing, is plausible in haddock, whiting and male cod, but unlikely for Norway pout, and does not explain trends in female cod maturation. In agreement with life-history theory, the maturation response was larger in fast-growing, late- and large-maturing species exhibiting moderate reproductive effort.

Organic Facies Characteristics of the Triassic Kasımlar Formation, Anamas-Akseki Platform, Western Taurides, Turkey

In the Anamas-Akseki platform (SW Turkey), the Triassic Kasımlar Formation consists of bituminous shale and bedded reefal limestones. Detailed data from thick Triassic sediments (Kasımlar Formation) made it possible to construct an organic facies framework using different zonations. Organic matter is composed predominantly of woody material, with a minor contribution of planty and amorphous material. Kerogen in the deposits is type III, as indicated by organic petrographic observations and Rock-Eval data. Total organic carbon (TOC) values are generally between 0.02 and 0.96%, but reach 3.78% in the formation. Tmax values vary between 284 and 454°C, confirming the increase in maturation trends indicated by vitrinite reflectance data. Organic facies type D was identified in the investigated units. Organic facies D is related to shale and carbonate lithofacies. This facies is characterized by average values of HI around 19 (equivalent to type III kerogene), TOC around 0.51%, and an average of S2 of 0.04mg HC/g of rock. Organic facies D is nongenerative; the organic matter is highly oxidized, decomposed and reworked.

GOCE gravity gradient data for lithospheric modeling

The Gravity field and steady-state Ocean Circulation Explorer (GOCE) is the European Space Agency's (ESA) satellite gravity mission to determine the Earth's mean gravity field. GOCE delivers gravity gradients, a new type of satellite data. We study how these data can improve modeling of the Earth's lithosphere. We discuss the use of the original GOCE gravity gradients versus the use of gravity gradients in grids at satellite altitude or close the Earth's surface and conclude that grids are easier to handle than the original data because one does not have to deal with very different error characteristics of the different gradients, given in a rotating frame at varying heights. The downward continuation to the surface enhances signal and better reflects the near-surface geology. But this does not outweigh the amplification of noise and omission errors, which is why we recommend using the field at mean satellite altitude for lithospheric modeling. The North-East Atlantic region is ideal to analyze the additional value of GOCE gravity gradients because it is a well-studied region in terms of regional geophysics. We calculated the gradient sensitivity for crustal depth slices using a 3D lithospheric model. This reveals that especially interfaces with large density contrasts have a distinct signal in the gravity gradients, but that they are quite insensitive to intra-crustal density sources, which can have quite a large effect on surface gravity data. We also show that the satellite gradients have a depth sensitivity well suited to study the upper mantle density structure, making them complementary to gravity and seismic tomography. In the underexplored Rub’al-Khali area the GOCE vertical gradient was used to invert for crustal thickness. The updated Moho model gives a good fit to four of the six gradients and independent depths from seismic stations. The Moho model was used to update the heat flow model and source rock maturity maps, which are generally consistent with known source rock maturity trends in the surrounding regions. GOCE gradients are therefore useful to map crustal thickness and deep regional structures for frontier areas. In combination with other data, heat flow can be modeled which is essential for basin maturity evaluation.

Long-term changes in maturation of sardine, <i>Sardina pilchardus</i>, in Portuguese waters

Long-term changes in sardine maturation were described using samples collected from landings off the western Portuguese coast since 1947. Estimates of the length at 50% maturity (L 50 ) were calculated in 44 years of the study period and proved to be good proxies of the maturation length of first-year spawners (Lp 50 of age 0-1 fish). Sardine probability of maturing at a given length declined from the early 1950s to the late 1960s, corresponding to an increase of ca. 2 cm in both L 50 and Lp 50 . This trend reversed in the early 1970s and halted in the early to mid-1990s. The tendency for sardine to mature at a lower length was positively correlated with improved body condition in the growing season preceding maturation. Long-term trends in sardine maturation and body condition were parallel to trends in sea surface temperature reported in the literature. The results suggest that maturation at a lower size is directly influenced by increased temperature, and that higher temperatures improve body condition through increased feeding efficiency or a combination of both. We found no evidence that fishing intensity has contributed to long-term changes in sardine maturation.

Papillary Squamous Cell Carcinoma of the Head and Neck

A relationship between human papillomavirus (HPV) infection and papillary squamous cell carcinoma (PSCC) has been suggested. However, to date, no studies have thoroughly and directly evaluated for transcriptional activity of the virus or the clinicopathologic significance of HPV-positive PSCC. Forty-eight cases of PSCC were retrieved from our surgical pathology database and were reviewed by 4 study pathologists, with tumors defined as SCC with a significant component of papillary growth in the tumor. Immunohistochemical analysis for p16 and p53 was performed. Overexpression of p16 was used as a surrogate marker of transcriptionally active HPV. Transcriptional activity was also directly evaluated using RNA in situ hybridization to detect high-risk HPV E6/E7 mRNA. Clinical follow-up data were obtained by chart review. Seven cases were located in the oral cavity, 19 in the oropharynx, and 22 in the larynx. Two morphologic types of PSCC were identified: keratinizing type, in which the epithelial cells showed a maturation trend with minimal surface parakeratin, and nonkeratinizing type, in which the papillae were completely covered by immature basaloid cells. Transcriptionally active HPV was present in 23 of 43 (53.4%) tumors. The majority of tumors harboring transcriptionally active HPV arose in the oropharynx, showed nonkeratinizing morphology, were p16 positive, and p53 negative. Transcriptionally active HPV was also present in many laryngeal and oral cavity PSCCs. Overall survival, disease-specific survival, and disease-free survival were favorable and did not significantly differ by anatomic subsite. However, HPV-related tumors showed a trend toward better survival.

A study of hydrocarbon generation and expulsion of the Nkporo Shales in Anambra Basin, Nigeria

This study is a contribution to our understanding of the hydrocarbon potentials of the Nkporo Shale in the Anambra Basin, Nigeria. The main objective was to simulate the hydrocarbon generation and expulsion in the Nkporo source horizons encountered in Igbariam-1, Iji-1, and Ajire-1 wells drilled in the basin, using the one-dimensional Genesis Zetaware basin modeling software. This software enabled the integration of burial and thermal influences on Nkporo source rocks with kinetic parameters, in order to define the timing of hydrocarbon generation and expulsion in relation to the main structural episodes in the basin. The Nkporo source horizons encountered in Igbariam-1 well (2,650 m) has not expelled hydrocarbons but has a remaining potential of 380 mg/gTOC. Conversely, in Iji-1 well (3,450 m) and Ajire-1 well (3,250 m), the Nkporo source rocks expelled oil of about 110–127 mg/gTOC and gas of about 85–125 mg/gTOC. The time of expulsion was in Eocene–Oligocene (51–30 My) at the rate of 10.5–11.5 mg/gTOC/My. The remaining potentials for Nkporo source rocks in Iji-1 and Ajire-1 wells are 160 and 125 mg/gTOC, respectively. The result shows an increasing trend in maturation, generation, and expulsion of hydrocarbons with increasing depth towards the southwestern part of the basin. This resulted in an increase in the generated hydrocarbon volumes to the south due to (a) increased burial depth and early maturation and (b) changing source lithofacies—more marine. The fault system linking potential reservoirs such as Owelli Sandstone to the source rock suggests a possible migration of the generated hydrocarbons to those reservoirs at that time.

Petroleum system analysis of the Hammerfest Basin (southwestern Barents Sea): Comparison of basin modelling and geochemical data

Exploration in the Hammerfest Basin, southwestern Barents Sea, has proven several petroleum systems and plays with the presence of multiple source rocks of mainly Jurassic and Triassic age. To date several fields and discoveries have been found and are described to mainly contain gaseous hydrocarbons with the presence, in some cases, of an oil leg.Our 3D Hammerfest Basin model shows that the Jurassic Hekkingen Formation and the Triassic Snadd and Kobbe formations reached high maturity levels (gas window) in the western and the northwestern margin. At the same time, this model reproduces the main hydrocarbon accumulations that have been found in the basin. An analysis of the volumetrics and the proportion of oil and gas contributions to each field and discovery, suggests that the gas contribution stems mainly from Triassic source rocks, while the oil phases contain variable proportions from the Jurassic Hekkingen Formation and Triassic source rocks.Gas isotope and maturity related biomarker ratios confirm the maturity trends derived from the basin modelling results. Light hydrocarbons indicate the influence of secondary processes (biodegradation and long distance migration) in the petroleum from the Goliat field and the Tornerose discovery. Age related biomarker ratios such as the ETR (extended tricyclic terpane ratio) and the C28/C29 steranes ratio did not provide a clear separation when evaluating a contribution from Jurassic vs. Triassic source rocks.

Influence of migration distance, maturity and facies on the stable isotopic composition of alkanes and on carbazole distributions in oils and source rocks of the Alpine Foreland Basin of Austria

The Austrian part of the Alpine Foreland Basin has been studied previously by organic geochemical methods to establish oil–oil and oil–source rock correlations. The lateral distance of oil fields to the position of mature source rocks (Lower Oligocene Schöneck and Eggerding formations) beneath the Alpine nappes in the south suggests long distance migration up to 50km. Minor compositional trends in W–E direction were obtained reflecting differences in depositional environment (facies) and maturity of potential source rocks. Therefore, the oil and source rock samples are thought to provide valuable insights into carbazole distributions in relation to migration distance, maturity and facies. Compound specific carbon isotope analyses on n-alkanes and isoprenoids reflect the W–E trend, already seen within the total hydrocarbon fractions. The observed trend toward lighter δ13C values of alkanes from oil fields in a W–E direction are consistent with lower δ13C values of organic matter in unit c and similar differences obtained from sediments of the Schöneck Formation at wells Oberhofen 1 (W) and Molln 1 (E). The δ13C patterns of n-alkanes and isoprenoids are in agreement with data obtained from the potential marine source rocks (Schöneck Formation) of the oils. The hydrogen isotopic composition of short chain n-alkanes (C15–19) of most oil samples are lower than the data obtained from the extracts of the marine Permian Kupferschiefer of the Polish Zechstein Basin at similar maturation stages. Only the oils from the western oil fields yield δD values of n-alkanes comparable to those obtained from marine source rocks. The data imply brackish water conditions during deposition of ‘unit c’ of the Schöneck Formation. Differences in the position of δD of isoprenoids in relation to the respective maturation trend line are most probably related to calibration errors. Alkylated carbazoles and benzocarbazoles are only present in sufficient amounts for quantification in oils sampled from the eastern fields. Rock extracts of the Schöneck Formation from drill cores Molln 1 (5200m depth, 0.92% Rr) and from the marginally mature (ca. 0.6% Rr) samples from well Oberhofen 1 (4300m depth) obtained sufficient amounts of carbazoles. The significantly different concentrations of benzocarbazoles in the extracts (around 10μg/g at Oberhofen 1; > 50μg/g at Molln 1) are related to maturity differences, whereas the predominance of 1-methylcarbazole in the Oberhofen samples is inferred to reflect differences in source rock facies. In the oils from the eastern deposits, neither the concentration ratios of methylcarbazoles, nor the benzocarbazole ratio show indications for the influence of facies differences. Maturity of oil expulsion is estimated on the basis of MPI 1 (Rc=0.76–0.88%), confirmed by sterane isomerization parameters. The results argue for a minor influence of maturity differences on the benzocarbazole ratios of the oil samples. The obtained ratios and the reservoir source fractionation parameters, calculated from the data of Molln 1 source rocks and the respective oils, show a systematic decrease with the estimated migration distance. The results argue for the applicability of benzocarbazoles for the assessment of relative differences in migration distances in oil plays characterized by minor differences in source rock facies and maturity during oil expulsion.

The Assessment of Atrial Function in Single Ventricle Hearts from Birth to Fontan: A Speckle-Tracking Study by Using Strain and Strain Rate

Single ventricle (SV) exercise performance is impaired and limited by reduced ventricular preload reserve. The atrium modulates ventricular filling, and enhancement of atrial compliance can increase cardiac performance. We aimed to study atrial mechanics in SV hearts across staged surgical palliation compared with healthy children by using novel speckle-tracking echocardiography techniques. A cross-sectional study of 81 patients with SV (1 day to 6.5 years) at 4 stages of surgical palliation (presurgery, 22; prebidirectional cavopulmonary anastomosis, 23; pre-Fontan, 22; post-Fontan, 14). The dominant atrium was assessed with speckle-tracking echocardiography for active (εact), conduit (εcon), and reservoir (εres) strain; strain rate (SR); and εact/εres ratio before each stage of surgical palliation. Findings were compared with the left atrium of 51 healthy children (1 day to 5.5 years). Single ventricle atrial size was increased (P < .01), and atrial εres was decreased (P < .01) compared with healthy controls. SV atrial εcon (P < .01) and SRcon (P < .0001) was decreased, increased εact persisted (P < .05), and εact/εres was increased (P < .001) between surgical stages. Although the expected maturational trend of increasing εcon, decreasing εact, and εact/εres occurred in SV, they lagged behind healthy maturational changes (P < .0001). Single ventricle atrium is dilated, has deceased compliance, decreased early diastolic emptying, and increased reliance on active atrial contraction for ventricular filling. This deviates from normal early childhood maturational changes and appears to parallel those of an atrium facing early ventricular diastolic dysfunction.

Neonatal clinical pharmacology

Effective and safe drug administration in neonates should be based on integrated knowledge on the evolving physiological characteristics of the infant who will receive the drug and the pharmacokinetics (PK) and pharmacodynamics (PD) of a given drug. Consequently, clinical pharmacology in neonates is as dynamic and diverse as the neonates we admit to our units while covariates explaining the variability are at least as relevant as median estimates. The unique setting of neonatal clinical pharmacology will be highlighted based on the hazards of simple extrapolation of maturational drug clearance when only based on 'adult' metabolism (propofol, paracetamol). Second, maturational trends are not at the same pace for all maturational processes. This will be illustrated based on the differences between hepatic and renal maturation (tramadol, morphine, midazolam). Finally, pharmacogenetics should be tailored to neonates, not just mirror adult concepts. Because of this diversity, clinical research in the field of neonatal clinical pharmacology is urgently needed and facilitated through PK/PD modeling. In addition, irrespective of already available data to guide pharmacotherapy, pharmacovigilance is needed to recognize specific side effects. Consequently, pediatric anesthesiologists should consider to contribute to improved pharmacotherapy through clinical trial design and collaboration, as well as reporting on adverse effects of specific drugs.

Reflectance measurements of zooclasts and solid bitumen in Lower Paleozoic shales, southern Scandinavia: Correlation to vitrinite reflectance

Reflectance measurements have been carried out on zooclasts (graptolites, chitinozoans, and vase-shaped microfossils) and other organic particles (vitrinite-like particles, porous/granular vitrinite-like particles, and solid bitumen) in Middle Cambrian to Upper Silurian shales from central and southern Sweden and the Danish island of Bornholm (Baltic Sea). The most abundant organic components in all the shales are fragments of graptolites and vitrinite-like particles. The reflectance distribution of these two types of components is largely identical, and it is suggested that the vitrinite-like particles are fragments of graptolites without any recognizable morphology. Reflectance measurements of graptolites and vitrinite-like particles yield well-defined reflectance populations. In samples with average Rgraptolite and average Rvitrinite-like of >0.75%Ro, the reflectance distributions are bimodal because of increasing bireflectance, and the average reflectance value of the well-defined lower reflecting population is arbitrarily used as maturity indicator. Our results suggest that with increasing thermal maturity the reflectance of graptolites increases faster than the predicted vitrinite reflectance. The relationship between graptolite reflectance and equivalent vitrinite reflectance can be expressed by the equation: VReqv=0.73R(graptolite+vitrinite-like)low+0.16. The ‘gas generation window’, which normally is considered to begin at a vitrinite reflectance of 1.3%Ro in post-Lower Paleozoic rocks containing vitrinite, starts, accordingly, at 1.56%Ro graptolite reflectance. Porous/granular vitrinite-like particles occur in minor amounts and they may represent graptolite fragments with a non-smooth surface. They generally yield slightly higher reflectance than non-granular vitrinite-like particles and graptolite fragments. The Middle Cambrian to Furongian (upper Cambrian) shales may contain sparse fragments of vase-shaped microfossils (VSM) that seem to follow the maturation trend of chitinozoans. In the present sample set, the reflectance of chitinozoans and VSM is comparable to that of graptolites at the same level of maturity. Reflectance measurements of solid bitumen are a poor maturity indicator, probably because bitumen can have various origins and morphologies and it may not be indigenous to the host rock.