bluuebunny/crossref_metadata_2025 huggingface dataset:
Debating the greening vs. browning of the North American boreal forest: differences between satellite datasets
Authors: ALCARAZ‐SEGURA DOMINGO , CHUVIECO EMILIO , EPSTEIN HOWARD E. , KASISCHKE ERIC S. , TRISHCHENKO ALEXANDER
Published: April 2009

A number of remote sensing studies have evaluated the temporal trends of the normalized difference vegetation index (NDVI or vegetation greenness) in the North American boreal forest during the last two decades, often getting quite different results. To examine the effect that the use of different datasets might be having on the estimated trends, we compared the temporal trends of recently burned and unburned sites of boreal forest in central Canada calculated from two datasets: the Global Inventory, Monitoring, and Modeling Studies (GIMMS), which is the most commonly used 8 km dataset, and a new 1 km dataset developed by the Canadian Centre for Remote Sensing (CCRS). We compared the NDVI trends of both datasets along a fire severity gradient in order to evaluate the variance in regeneration rates. Temporal trends were calculated using the seasonal Mann–Kendall trend test, a rank‐based, nonparametric test, which is robust against seasonality, nonnormality, heteroscedasticity, missing values, and serial dependence. The results showed contrasting NDVI trends between the CCRS and the GIMMS datasets. The CCRS dataset showed NDVI increases in all recently burned sites and in 50% of the unburned sites. Surprisingly, the GIMMS dataset did not capture the NDVI recovery in most burned sites and even showed NDVI declines in some burned sites one decade after fire. Between 50% and 75% of GIMMS pixels showed NDVI decreases in the unburned forest compared with <1% of CCRS pixels. Being the most broadly used dataset for monitoring ecosystem and carbon balance changes, the bias towards negative trends in the GIMMS dataset in the North American boreal forest has broad implications for the evaluation of vegetation and carbon dynamics in this region and globally.
Knowing the past to predict the future: land‐use change and the distribution of invasive bullfrogs
Authors: FICETOLA GENTILE FRANCESCO , MAIORANO LUIGI , FALCUCCI ALESSANDRA , DENDONCKER NICOLAS , BOITANI LUIGI , PADOA‐SCHIOPPA EMILIO , MIAUD CLAUDE , THUILLER WILFRIED
Published: April 2009

Biological invasions and land‐use changes are two major causes of the global modifications of biodiversity. Habitat suitability models are the tools of choice to predict potential distributions of invasive species. Although land‐use is a key driver of alien species invasions, it is often assumed that land‐use is constant in time. Here we combine historical and present day information, to evaluate whether land‐use changes could explain the dynamic of invasion of the American bullfrogRana catesbeiana(=Lithobathes catesbeianus) in Northern Italy, from the 1950s to present‐day. We usedmaxentto build habitat suitability models, on the basis of past (1960s, 1980s) and present‐day data on land‐uses and species distribution. For example, we used models built using the 1960s data to predict distribution in the 1980s, and so on. Furthermore, we used land‐use scenarios to project suitability in the future. Habitat suitability models predicted well the spread of bullfrogs in the subsequent temporal step. Models considering land‐use changes predicted invasion dynamics better than models assuming constant land‐use over the last 50 years. Scenarios of future land‐use suggest that suitability will remain similar in the next years. Habitat suitability models can help to understand and predict the dynamics of invasions; however, land‐use is not constant in time: land‐use modifications can strongly affect invasions; furthermore, both land management and the suitability of a given land‐use class may vary in time. An integration of land‐use changes in studies of biological invasions can help to improve management strategies.
Temperature adaptation of soil bacterial communities along an Antarctic climate gradient: predicting responses to climate warming
Authors: RINNAN RIIKKA , ROUSK JOHANNES , YERGEAU ETIENNE , KOWALCHUK GEORGE A. , BÅÅTH ERLAND
Published: April 2009

Soil microorganisms, the central drivers of terrestrial Antarctic ecosystems, are being confronted with increasing temperatures as parts of the continent experience considerable warming. Here we determined short‐term temperature dependencies of Antarctic soil bacterial community growth rates, using the leucine incorporation technique, in order to predict future changes in temperature sensitivity of resident soil bacterial communities. Soil samples were collected along a climate gradient consisting of locations on the Antarctic Peninsula (Anchorage Island, 67 °34′S, 68 °08′W), Signy Island (60 °43′S, 45 °38′W) and the Falkland Islands (51 °76′S 59 °03′W). At each location, experimental plots were subjected to warming by open top chambers (OTCs) and paired with control plots on vegetated and fell‐field habitats. The bacterial communities were adapted to the mean annual temperature of their environment, as shown by a significant correlation between the mean annual soil temperature and the minimum temperature for bacterial growth (Tmin). Every 1 °C rise in soil temperature was estimated to increase Tmin by 0.24–0.38 °C. The optimum temperature for bacterial growth varied less and did not have as clear a relationship with soil temperature. Temperature sensitivity, indicated by Q10 values, increased with mean annual soil temperature, suggesting that bacterial communities from colder regions were less temperature sensitive than those from the warmer regions. The OTC warming (generally <1 °C temperature increases) over 3 years had no effects on temperature relationship of the soil bacterial community. We estimate that the predicted temperature increase of 2.6 °C for the Antarctic Peninsula would increase Tmin by 0.6–1 °C and Q10 (0–10 °C) by 0.5 units.
Increasing importance of small phytoplankton in a warmer ocean
Authors: MORÁN XOSÉ ANXELU G. , LÓPEZ‐URRUTIA ÁNGEL , CALVO‐DÍAZ ALEJANDRA , LI WILLIAM K. W.
Published: April 2009

The macroecological relationships among marine phytoplankton total cell density, community size structure and temperature have lacked a theoretical explanation. The tiniest members of this planktonic group comprise cyanobacteria and eukaryotic algae smaller than 2 μm in diameter, collectively known as picophytoplankton. We combine here two ecological rules, the temperature–size relationship with the allometric size‐scaling of population abundance to explain a remarkably consistent pattern of increasing picophytoplankton biomass with temperature over the −0.6 to 22 °C range in a merged dataset obtained in the eastern and western temperate North Atlantic Ocean across a diverse range of environmental conditions. Our results show that temperature alone was able to explain 73% of the variance in the relative contribution of small cells to total phytoplankton biomass regardless of differences in trophic status or inorganic nutrient loading. Our analysis predicts a gradual shift toward smaller primary producers in a warmer ocean. Because the fate of photosynthesized organic carbon largely depends on phytoplankton size, we anticipate future alterations in the functioning of oceanic ecosystems.
Phylogeographical structure in the coastal species Senecio rodriguezii (Asteraceae), a narrowly distributed endemic Mediterranean plant
Authors: Molins Arántzazu , Mayol Maria , Rosselló Josep A.
Published: April 2009

Aim  Our goals were (1) to assess the levels of chloroplast DNA variation in a narrowly distributed plant restricted to continental islands, (2) to ascertain whether a phylogeographical structure is present in plants restricted to coastal linear systems, and (3) to interpret the results in the light of the known palaeogeography of these islands.

Location  The Eastern Balearic Islands (Majorca and Minorca) in the Western Mediterranean Basin.

Methods  Sampling included 134 individuals from 28 populations of Senecio rodriguezii covering the entire range of the species. Sequences of the chloroplast genome (trnT–trnL spacer) were obtained and parameters of population genetic diversity and substructure were determined (hsht, Gst). The geographical structure of genetic variation was assessed by an analysis of molecular variance (AMOVA). Additionally, a spatial AMOVA (SAMOVA) was used to identify groups of populations that were geographically homogeneous and maximally differentiated from each other. Finally, a pattern of isolation by distance was assessed by testing the correlation between the matrix of pairwise ΦST values and the matrix of geographical distances between pairs of populations using a Mantel test.

Results  Seven haplotypes were detected in S. rodriguezii. Only two of them were shared between islands; all of the others were restricted to Majorca (two) or Minorca (three). Overall, we found high levels of genetic diversity and significant geographical structuring of cpDNA markers. Most of the variation detected can be attributed to differences among populations (84.6%), but there was also a significant differentiation between the islands.

Main conclusions  Our results support the view that the Balearic Islands constitute a reservoir of genetic diversity, not only for widespread Mediterranean taxa, but also for endemic ones. The intraspecific genetic structure found in S. rodriguezii suggests that its population history was dominated by both expansion and contraction events. This has resulted in a species that is highly structured genetically, showing very few shared haplotypes between islands, and a high number of haplotypes restricted to small geographical areas within the islands. Changes in habitat availability and dynamic processes of population fragmentation and connectivity due to repeated cycles of sea‐level changes during the Quaternary are the possible underlying factors that have shaped the cpDNA pool of this endemic species on a regional scale.
Out of sight, out of mind: high cryptic diversity obscures the identities and histories of geminate species in the marine bivalve subgenus Acar
Authors: Marko P. B. , Moran A. L.
Published: April 2009

Aim  The rise of the Isthmus of Panama and the formation of ‘geminate’ species pairs serves as an important model of allopatric speciation. However, to function as a model system, hypothesized geminates must first be shown to be each other’s closest living relatives. If the presence of cryptic taxa obscures true relationships, the biogeographical histories of transisthmian taxa are likely to be misinterpreted. We have therefore completed a phylogeographic survey of the transisthmian bivalve subgenus Acar in the genus Barbatia to characterize patterns of tropical American diversity and to place transisthmian taxa in a regional phylogeographic context.

Location  Tropical America.

Methods  Mitochondrial cytochrome c oxidase I (COI) and nuclear internal transcribed spacer (ITS) sequences were obtained from 233 specimens of Acar. Sequences were analysed using cladistic and Bayesian methods. Divergence times between species were inferred from net nucleotide divergences and a coalescence‐based method.

Results  The survey revealed 22 COI clades that were also monophyletic at ITS, indicating that the taxonomy of Acar is potentially greater than a fivefold diversity underestimate. The lone previously recognized geminate [Barbatia (Acar) gradata and Barbatia (Acar) domingensis] is composed of 15 clades. Among the four transisthmian lineages identified, two diverged more than 14 Ma; the two other geminates split just prior to the time of final seaway closure. In addition to a fourfold increase in the number of known geminates, our data show that within‐basin diversification has been more impressive, with one geminate splitting into five monophyletic clades in the Western Atlantic alone since seaway closure. Electron microscopy of the larval shells of specimens indicates that the transisthmian lineage with the greatest rate of post‐Isthmian diversification possesses non‐planktonic larvae, a life‐history feature linked to high speciation rates.

Main conclusions  Our analyses revealed that the identities of geminate pairs split by the Isthmus of Panama were obscured by extremely high tropical American cryptic diversity. Although we have identified four geminates, only two appear to have been split by the Isthmus. Our uncovering of extensive post‐Isthmian diversification is consistent with the palaeontological perspective that the final closure of the Central American Seaway was followed by high rates of subgeneric diversification, particularly in the tropical Western Atlantic.
Invasion and survival of Photobacterium damselae subsp. piscicida in non‐phagocytic cells of gilthead sea bream, Sparus aurata L.
Authors: Acosta F , Vivas J , Padilla D , Vega J , Bravo J , Grasso V , Real F
Published: April 2009

Fluorescence microscopy and gentamicin protection assays were used to investigate the ability of four Photobacterium damselae subsp. pisicida (Phdp) strains to adhere to and to invade the fish epithelial cell line, SAF‐1, derived from Sparus aurata. All strains tested were detected intracellularly using both techniques, although internalization levels varied among strains. Treatment with cytochalasin D and experiments carried out at 4 °C demonstrated that a functional host cell cytoskeleton and active cell metabolism are necessary for bacterial internalization. Intracellular bacteria were detected for up to 7 days with a round morphology and were stained with DAPI, indicating that some bacterial cells may remain viable inside SAF‐1 cells. Our in vitro findings indicate that Phdp are capable of adhering, entering and surviving within the non‐phagocytic epithelial cell line SAF‐1, which may be important for persistence and establishment of a carrier state in S. aurata.
Impaired Nocturnal Melatonin in Acute Phase of Ischaemic Stroke: Cross‐Sectional Matched Case–Control Analysis
Authors: Atanassova P. A. , Terzieva D. D. , Dimitrov B. D.
Published: April 2009

Quantitative data on melatonin in stroke patients are scarce. A gender‐ and age‐matched cross‐sectional case–control study in 33 patients with ischaemic stroke was performed and associations between nocturnal melatonin and other factors (e.g. cortisol) were evaluated. Clinical and laboratory (e.g. melatonin and cortisol) measurements (03.00 h and 08.00 h) with statistical techniques [e.g. multifactorial regressions, receiver operating characteristic (ROC) curve and curvilinear estimations] were used. We identified mean value and 95% confidence interval (CI) (69.70 pg/ml; 95% CI = 53.86–85.54) for control levels of nocturnal melatonin in healthy subjects. The patients with stroke had lower melatonin (48.1 ± 35.9 pg/ml) and higher cortisol (297.3 ± 157.8 nmol/l) at 03.00 h (P < 0.05) but not at 08.00 h (P > 0.05). Stroke was the strongest factor of disturbed nocturnal cortisol (P < 0.001), whereas decreased melatonin depended on stroke (P = 0.010) and gender (P = 0.018). At the same time, vice versa, only nocturnal measures were associated with an increased probability of the presence of stroke (accuracy > 75%, Pmodel < 0.001). Thus, a hypothesis that a decrease of melatonin with 1.0 pg/ml might be associated with > 2% increase in the probability of the presence of stroke [adjusted odds ratio (OR) = 1.020; 95% CI = 1.002–1.037] was also suggested. The ROC curve (0.67, P = 0.0119) and optimisation techniques indicated that a novel best cut‐off < 51.5 pg/ml for decreased nocturnal melatonin in the view of the presence of stroke (OR = 3.12, P = 0.0463) might exist. The classification performance of such a cut‐off might be confirmed by existing nocturnal melatonin and cortisol differences between the sub‐groups; potential differences in diurnal melatonin were also suggested. In conclusion, a novel melatonin cut‐off of 51.5 pg/ml may be associated with the presence of ischaemic stroke. As a single marker (84% sensitivity, 74% specificity), it is hypothesised that modelling performance was independent of age, gender and cortisol. These new results, including the suggested hypothesis, might be further tested in follow‐up (cohort), longitudinal studies and be applied to explore melatonin disturbances as targets in high‐risk pre‐stroke and post‐stroke patients.
Prediction of the prognosis of patients with acute‐on‐chronic hepatitis B liver failure using the model for end‐stage liver disease scoring system and a novel logistic regression model
Authors: Sun Q.‐F. , Ding J.‐G. , Xu D.‐Z. , Chen Y.‐P. , Hong L. , Ye Z.‐Y. , Zheng M.‐H. , Fu R.‐Q. , Wu J.‐G. , Du Q.‐W. , Chen W. , Wang X.‐F. , Sheng J.‐F.
Published: April 2009

Summary.  The objective of this study was to determine the predictive value of the model for end‐stage liver disease (MELD) scoring system in patients with acute‐on‐chronic hepatitis B liver failure (ACLF‐HBV), and to establish a new model for predicting the prognosis of ACLF‐HBV. A total of 204 adult patients with ACLF‐HBV were retrospectively recruited between July 1, 2002 and December 31, 2004. The MELD scores were calculated according to the widely accepted formula. The 3‐month mortality was calculated. The validity of the MELD model was determined by means of the concordance (c) statistic. Clinical data and biochemical values were included in the multivariate logistic regression analysis based on which the regression model for predicting prognosis was established. The receiver‐operating characteristic curves were drawn for the MELD scoring system and the new regression model and the areas under the curves (AUC) were compared by the z‐test. The 3‐month mortality rate was 57.8%. The mean MELD score for the patients who died was significantly greater than those who survived beyond 3 months (28.7 vs 22.4, P = 0.003). The concordance (c) statistic (equivalent to the AUC) for the MELD scoring system predicting 3‐month mortality was 0.709 (SE = 0.036, P < 0.001, 95% confidence interval 0.638–0.780). The independent factors predicting prognosis were hepatorenal syndrome (P < 0.001), liver cirrhosis (P = 0.009), HBeAg (P = 0.013), albumin (P = 0.028) and prothrombin activity (P = 0.011) as identified in multivariate logistic regression analysis. The regression model that was constructed by the logistic regression analysis produced a greater prognostic value (c = 0.891) than the MELD scoring system (z = 4.333, P < 0.001). The MELD scoring system is a promising and useful predictor for 3‐month mortality of ACLF‐HBV patients. Hepatorenal syndrome, liver cirrhosis, HBeAg, albumin and prothrombin activity are independent factors affecting the 3‐month mortality. The newly established logistic regression model appears to be superior to the MELD scoring system in predicting 3‐month mortality in patients with ACLF‐HBV.
Liver fibrosis in patients with chronic hepatitis C and persistently normal liver enzymes: influence of HIV infection
Authors: Martin‐Carbonero L. , De Ledinghen V. , Moreno A. , Maida I. , Foucher J. , Barreiro P. , Romero M. , Satta G. , Garcia‐Samaniego J. , Gonzalez‐Lahoz J. , Soriano V.
Published: April 2009

Summary.  Liver fibrosis progress slowly in patients with chronic hepatitis C and persistently normal alanine aminotransferase (PNALT) compared to subjects with elevated aminotransferases. Differences in liver fibrosis according to human immunodeficiency virus (HIV) status in this population have not been examined. All patients with serum hepatitis C virus (HCV)‐RNA and PNALT who underwent liver fibrosis assessment using elastometry since 2004 at three different European hospitals were evaluated. Patients previously treated with interferon were excluded. PNALT was defined as ALT below the upper limit of normality in at least three consecutive determinations within the last 12 months. Fibrosis stage was defined as mild (Metavir F0–F1) if stiffness ≤7.1 kPa; moderate (F2) if 7.2–9.4 kPa; severe (F3) if 9.5–14 kPa, and cirrhosis (F4) if >14 kPa. A total of 449 HIV‐negative and 133 HIV‐positive patients were evaluated. HIV‐negative patients were older (mean age 51.8 vs 43.5 years) and more frequently females (63%vs 37%) than the HIV counterparts. Mean serum HCV‐RNA was similar in both the groups (5.9 vs 5.8 log IU/mL). Overall, 78.8% of the HIV patients were on HAART and their mean CD4 count was 525 (±278) cells/μL. In HIV‐negatives, liver fibrosis was mild in 84.6%; moderate in 8.7%, severe in 3.3% and cirrhosis was found in 3.3%. In HIV patients, these figures were 70.7%, 18.8%, 6%, and 4.5%, respectively. In the multivariate logistic regression analysis, older age (odds ratio or OR: 1.04; 95% confidence interval or CI: 1.02–1.07; P < 0.001) and being HIV+ (OR: 2.6; 95% CI: 1.21–5.85; P < 0.01) were associated with severe liver fibrosis or cirrhosis (F3–F4). Thus, severe liver fibrosis and cirrhosis are seen in 6.6% of the HCV‐monoinfected and in 10.5% of HCV‐HIV co‐infected patients with PNALT. Some degree of liver fibrosis that justifies treatment is seen in 15% of the HCV‐monoinfected but doubles to nearly 30% in HIV‐HCV co‐infected patients with PNALT.
pH measurement as quality control on human post mortem brain tissue: a study of the BrainNet Europe consortium
Authors: Monoranu C. M. , Apfelbacher M. , Grünblatt E. , Puppe B. , Alafuzoff I. , Ferrer I. , Al‐Saraj S. , Keyvani K. , Schmitt A. , Falkai P. , Schittenhelm J. , Halliday G. , Kril J. , Harper C. , McLean C. , Riederer P. , Roggendorf W.
Published: April 2009

Aims: Most brain diseases are complex entities. Although animal models or cell culture experiments mimic some disease aspects, human post mortem brain tissue remains essential to advance our understanding of brain diseases using biochemical and molecular techniques. Post mortem artefacts must be properly understood, standardized, and either eliminated or factored into such experiments. Here we examine the influence of several premortem and post mortem factors on pH, and discuss the role of pH as a biochemical marker for brain tissue quality. Methods: We assessed brain tissue pH in 339 samples from 116 brains provided by 8 different European and 2 Australian brain bank centres. We correlated brain pH with tissue source, post mortem delay, age, gender, freezing method, storage duration, agonal state and brain ischaemia. Results: Our results revealed that only prolonged agonal state and ischaemic brain damage influenced brain tissue pH next to repeated freeze/thaw cycles. Conclusions: pH measurement in brain tissue is a good indicator of premortem events in brain tissue and it signals limitations for post mortem investigations.
Panencephalopathic Creutzfeldt–Jakob disease in the Netherlands and the UK: clinical and pathological characteristics of nine patients
Authors: Jansen C. , Head M. W. , Rozemuller A. J. M. , Ironside J. W.
Published: April 2009

Aims: The panencephalopathic type of Creutzfeldt–Jakob disease (PECJD) has extensive abnormalities in cerebral white matter as well as the cortex. PECJD has rarely been described in Caucasians and debate continues on its classification and pathogenesis. We describe our experience of PECJD over a 14‐year period of surveillance for CJD in the Netherlands and the UK. Methods: Between 1993 and 2006, nine cases of PECJD were identified. Clinical, histological and biochemical characteristics of all patients were analysed and compared; all cases were classified clinically as sporadic CJD. Results: The median age at onset was 57.8 years and median disease duration was 22 months. The average brain weight was 887 g. Most patients showed a two‐stage clinical course with initial rapid deterioration to a state of akinetic mutism, which then persisted over a longer time scale. Neuropathological findings were characterized by severe global atrophy with status spongiosus. Cerebral white matter involvement tended to be associated with either disease duration or severity of cerebral cortical lesions. Five patients could be classified into the MM1 subtype of sporadic CJD, one patient into the MM2 subgroup and another into the MV2 subgroup. Two patients were heterozygous at codon 129 in the prion protein gene and contained both type 1 and type 2 PrPres isoforms in the brain. Conclusions: We believe that white matter pathology in PECJD represents an end‐stage pattern that reflects secondary degeneration due to widespread cortical neuronal loss that occurs in the early part of the disease, rather than representing a primary lesion.
Low‐dose cyclosporine A therapy increases the regulatory T cell population in patients with atopic dermatitis
Authors: Brandt C. , Pavlovic V. , Radbruch A. , Worm M. , Baumgrass R.
Published: April 2009

Background:  Atopic dermatitis (AD) is a T cell dependent chronic relapsing inflammatory skin disorder successfully treated with cyclosporine A (CsA). Clinical observations indicate that even low‐dose CsA therapy is successful in severely affected AD patients. We studied the impact of low‐dose CsA therapy on the ability of T helper cells to be activated, and examined whether regulatory T (Treg) cells are increased in these patients.

Methods:  Peripheral T cells were activated in a whole blood sample and interleukin‐2 producing cells were measured by intracellular cytokine staining. Regulatory T cells were analyzed by intracellular FoxP3 staining. Regulatory T cells (CD4+CD25+CD127low) and effector T cells (CD4+CD25−CD127+) were sorted by flow cytometry and used for suppression assays.

Results:  A group of AD patients treated with low‐dose CsA had a significantly larger Treg cell population than a healthy control subject group. In individual patients, onset of low‐dose CsA therapy reduced the ability of T cells to be activated to 42 ± 18% (P < 0.005) and significantly increased Treg cells, both in absolute numbers (1.6‐fold change) and frequencies (1.7‐fold change). Treg cells from AD patients showed similar suppressive capacities as Treg cells from healthy donors. Furthermore, Treg cells from AD patients had skin homing properties.

Conclusion:  Our results indicate that the therapeutic effect of low‐dose CsA therapy in AD patients might be not only mediated by the inhibition of T cell hyperactivity but also by an increased population of Treg cells.
Conflicting selection on diaspore traits limits the evolutionary potential of seed dispersal by ants
Authors: MANZANEDA A. J. , REY P. J. , ALCÁNTARA J. M.
Published: April 2009

Conflicts of selection on diaspore traits throughout the dispersal cycle can limit the evolutionary consequences of seed dispersal. However, these conflicts have never been investigated in directed dispersal systems. We explored conflicts of selection through life stages of dispersal in the myrmecochorous herb Helleborus foetidus. Seeds are subject to two contrasting partial selective scenarios. Undispersed seeds are subject to positive directional selection on seed size characters, whereas seeds dispersed are subject to stabilizing selection for size. In both scenarios, seedling establishment determined the magnitude and direction of selection. This does not reflect ant preferences for seed size. However, total selection still depends largely on ant activity, as ants control the relative importance of each selective scenario. We advocate the use of analytical approaches combining multiplicative fitness and microenvironment‐specific selection to more realistically estimate the realized selection on traits functional during several life stages. This approach may be extended to any organism dispersing offspring to different environments.
Translocons on the inner and outer envelopes of chloroplasts share similar evolutionary origin in Arabidopsis thaliana
Authors: LV H.‐X. , GUO G. Q. , YANG Z.‐N.
Published: April 2009

The process of importing nuclear encoded proteins into chloroplasts is mediated by the Translocons on the Outer/Inner Envelope of Chloroplasts (TOC and TIC complex). The ancestor of the TOC complex was formed by pre‐existing proteins from the cyanobacterial ancestor; other proteins recruited from the host cell or cyanobacterial ancestor were subsequently integrated into the complex. However, little is known about the origin of the TIC complex. In this work, the origin of the TIC complex was investigated through one of its channel proteins, AtTic21. Phylogenetic analysis suggested that AtTic21 is conserved in photosynthetic organisms. AtTic21 showed 33% sequence identity to a Synechocystis protein SynTic21. The successful genetic complementation of an AtTic21 knockout mutant by SynTic21 plus the transit peptide coding sequence of AtTic21 suggested that SynTic21 is an ortholog of AtTic21. The sequence and functional conservation between SynTic21 and AtTic21 suggested that the TIC complex shares a similar evolutionary origin to the TOC complex.
Inbreeding depresses short and long distance dispersal in three congeneric spiders
Authors: BONTE D.
Published: April 2009

Dispersal is one of the most important precopulatory inbreeding avoidance mechanisms and subject to landscape related selection pressures. In small populations, inbreeding within and between populations may strongly affect population dynamics if it reduces fitness and gene‐flow. While inbreeding avoidance is generally considered to be a key evolutionary driver of dispersal, potential effects of inbreeding on the dispersal process, are poorly known. Here, I document how inbreeding within a population, so by mating among relatives, affects the survivorship and the dispersal behaviour of three congeneric spider Erigone species (Araneae: Linyphiidae) that differ in habitat preference and regional rarity. The three species were chosen as a model because they allow the assessment of both long and short distance dispersal motivation (respectively ballooning and rappelling) under laboratory conditions. Inbreeding reduced both long and short distance dispersal modes in the three congeneric species. Because survival was depressed after inbreeding, with a tendency of reduced survival loss in the rare and highly stenotopic species, energetic constraints are likely to be the underlying mechanism. Inbreeding consequently depresses silk‐related dispersal in three related spiders. This may induce an inbreeding depression vortex with important consequences for range expansion and metapopulation dynamics of aerially dispersing species from highly fragmented landscapes.
Occurrence of Alaskan‐type mafic‐ultramafic intrusions in the North Qilian Mountains, northwest China: Evidence of Cambrian arc magmatism on the Qilian Block
Authors: Tseng Chien‐Yuan , Zuo Guo‐Chao , Yang Huai‐Jen , Yang Houng‐Yi , Tung Kuo‐An , Liu Dun‐Yi , Wu Han‐Quan
Published: April 2009

Field relationships, mineralogy and petrology, whole‐rock chemistry, and age of the Zhamashi mafic–ultramafic intrusion in the North Qilian Mountains, northwest China, have been studied in the present work. The Zhamashi intrusive body consists of ultramafic, gabbroic, and dioritic rocks in a crudely concentrically zoned structure. The ultramafic rocks are layered cumulates with rock types varying continuously from dunite through wehrlite and olivine clinopyroxenite to clinopyroxenite. The gabbroic and dioritic rocks are also layered or massive cumulates with rock types varying continuously from noritic gabbro through hornblende gabbro to diorite. The ultramafic and adjoining gabbroic rocks are discontinuous in lithology and discordant in structure across the interface. The interface is steep, sharp, and fractured. Contact metamorphic zones are well developed between the Zhamashi intrusive body and the country rock. The concentrically zoned structure of the intrusive body and the intrusion into the continental crust are the two main pieces of evidence for considering that the Zhamashi intrusion is Alaskan‐type. The mineral chemistry of the chromian spinels (Cr‐spinels) and clinopyroxenes, and the variation trend of the whole‐rock compositional plot in the (Na2O + K2O)–FeO–MgO (AFM) diagram are also supportive of this consideration. The age of the Zhamashi intrusive body, determined with sensitive high mass‐resolution ion microprobe on the zircon grains, is 513.0 ± 4.5 Ma. Parental magma of the Zhamashi intrusion is compositionally close to the primitive magma produced by partial melting of the mantle peridotite. It was differentiated by fractional crystallization at low total pressure and under H2O‐rich conditions in an arc environment to form all the major rock types. The concentrically zoned structure of the Zhamashi intrusive body was constructed in two stages: formation of a stratiform‐type layered sequence, followed by diapiric re‐emplacement. The occurrence of the Alaskan‐type intrusion suggests an active continental margin and Cambrian arc magmatism for the northern margin of the Qilian Block.
Formation of chaotic rock units during primary accretion processes: Examples from the Miura–Boso accretionary complex, central Japan
Authors: Yamamoto Yuzuru , Nidaira Manami , Ohta Yasufumi , Ogawa Yujiro
Published: April 2009

Chaotic rock units exposed in the upper part of the accretionary complex preserve detailed tectonic information related to the periods before, during, and immediately after accretion. Based on the detailed survey in the upper Miocene Miura–Boso accretionary complex, central Japan, three types of chaotic rock units were identified on the basis of the grain sizes and characteristics of blocks and surrounding matrices. The chaotic rock units composed of silt matrices and sandy to pebbly blocks (Type 3) formed by gravity‐driven slumping upon the seafloor. The slumping occurred contemporaneously with deposition of the Misaki and Nishizaki Formations within the Izu–Bonin forearc. Vertical variations in the direction of slump vergence represent successive changes from an initially flat seabed to tilting to the northwest and finally to the southeast. Slumping with a northwest vergence indicates landward tilting of the seafloor immediately prior to accretion, whereas vergence to the southeast reflects oceanward tectonic tilting that occurred once the sediments had crossed the deformation front. Other chaotic rock units that have matrices abundant in sand and pebbles (Types 1, 2) formed as a result of subsurface liquefaction and injection associated with large earthquakes that occurred during and after accretion of the sediments. These chaotic rock units are useful in examining surface/subsurface changes such as tectonic tilting of the seafloor and earthquake events during the initial accretion process.
Foraminiferal evidence of submarine sediment transport and deposition by backwash during the 2004 Indian Ocean tsunami
Authors: Sugawara Daisuke , Minoura Koji , Nemoto Naoki , Tsukawaki Shinji , Goto Kazuhisa , Imamura Fumihiko
Published: April 2009

Micropaleontological analysis of nearshore to offshore sediments recovered from the southwestern coast of Thailand was performed to clarify the submarine processes of sediment transport and deposition during the 2004 Indian Ocean tsunami. The distribution pattern of benthic foraminifers showed seaward migration after the tsunami event. Agglutinated foraminifers, which are characteristic of an intertidal brackish environment, were identified in the post‐tsunami samples from foreshore to offshore zones. These suggest that sediments originally distributed in foreshore to nearshore zones were transported offshore due to the tsunami backwash. On the other hand, the distribution pattern of planktonic and benthic species living in offshore zones showed slight evidence of landward migration by the tsunami. This suggests that landward redistribution of sediments by the tsunami run‐up did not occur in the offshore seafloor of the study area. Our results and a review of previous studies provide an interpretation of submarine sedimentation by tsunamis. It is possible that tsunami backwashes induce sediment flows that transport a large amount of coastal materials seaward. Thus, traces of paleotsunami backwashes can be identified in offshore sedimentary environments as the accumulation of allochthonous materials. This can be recognized as changes in benthic foraminiferal assemblages.
Health and well‐being in school‐age children following persistent crying in infancy
Authors: Brown Mary , Heine Ralf G , Jordan Brigid
Published: April 2009

Aim:  To examine the physical and mental health outcomes at school‐age of a cohort of children who participated in a randomised clinical trial of treatments for persistent crying in infancy.

Methods:  Participants and parents attended for a standard physical examination and clinical mental health assessment of the children. Parents completed the Strength and Difficulties Questionnaire (SDQ), Child Health Questionnaire (CHQ), Forsyth Child Vulnerability Scale, Recent Life Events Questionnaire, RAND‐36 Health Status Inventory and a study questionnaire about medical and socio‐demographic characteristics.

Results:  Seventy‐five of 127 (59%) traced infant–parent dyads participated. There were no significant differences in baseline demographic characteristics, infant crying or maternal stress between those who participated and those who declined. Mothers who participated had higher Edinburgh Postnatal Depression Scale scores. The study group had poorer mental health, as measured on the SDQ, than a community sample (26.3% vs. 9.9% abnormal cases, risk ratio 2.56 (confidence interval 1.72, 3.80)). Fifteen of 61 (24.6%) children who attended for the clinical mental health assessment met Diagnostic and Statistical Manual of Mental Disorders, 4th edition, criteria for a mental disorder. In the 4 weeks preceding the assessment, the child's health limited family activities more than in a community sample (CHQ‐Family Activities; P < 0.001). Parents had less time for personal needs compared with community norms (CHQ‐Parent Time; P < 0.001) and were more likely to worry about their child's health (CHQ‐Parent E; P < 0.001).

Conclusion:  At school‐age, children with a history of hospitalisation for persistent crying in infancy had a significantly higher prevalence of mental health problems and mental disorders, as compared with community samples.
Implementation of a checklist to assist in the rapid identification of seriously ill children in the emergency department: An observational study
Authors: Hayden Georgina , Hewson Peter H , Eddey David , Smith Darren , Vuillermin Peter J
Published: April 2009

Aim:  Interventions are required to expedite the identification and treatment of seriously ill children in the emergency department (ED). The aim of this study was to test the hypothesis that the implementation of a features of serious illness in children checklist (FSIC) for ED nursing staff would be associated with a reduction in the presentation‐to‐treatment time (PTTT) among children who required hospital admission and active treatment.

Methods:  An observational study was conducted 8 weeks before and 8 weeks after the implementation of the FSIC. The study was conducted in a busy combined adult and paediatric ED. Participants were children admitted to the hospital via the ED with a potentially life‐threatening illness.

Results:  A total of 3640 patients age less than 18 years attended the ED during the observation period. Of these, 214 patients met the eligibility criteria: 111 pre‐FSIC and 103 post‐FSIC. The overall ED workload and case‐mix were similar during the two observation periods. The PTTT was on average 16% (95% confidence interval, 17–33%; P = 0.302) longer following the implementation of the FSIC.

Conclusion:  The implementation of a checklist to assist ED nursing staff in the identification of seriously ill children was not effective in reducing the delay between presentation and the initiation of treatment among children who were admitted to the hospital. Larger studies are required to determine whether similar strategies are effective among a more critically ill subgroup. Consideration should also be given to alternative strategies to expedite the identification and treatment of seriously ill children in the ED.
Outcome of biliary atresia in Malaysia: A single‐centre study
Authors: Lee Way‐Seah , Chai Pei‐Fan , Lim Kean‐Seng , Lim Li‐Han , Looi Lai‐Meng , Ramanujam Trndivanam Muthurangam
Published: April 2009

Aim:  This study aimed to determine the outcome of the operation of children with biliary atresia (BA) at a tertiary paediatric referral centre in Malaysia.

Methods:  A prospective study on all patients with BA referred to the University of Malaya Medical Centre (UMMC), Kuala Lumpur, from 1996 to 2005 was conducted. Survival with native liver, liver transplantation (LT) or death at 2 years of age was determined.

Results:  The median age at referral of the 57 patients with BA seen at University of Malaya Medical Centre was 62 days. Kasai procedure was not performed in nine patients who were all referred late (median age of referral 180 days). The median age at hepatoportoenterostomy (HPE) of the remaining 48 patients was 70 days. A total of 53 (93%) patients had type 3 BA, while only 1 (2%) patient had BA splenic malformation. At 2 years, the survival rate with native liver for the 48 patients who had HPE was 37%, while the overall survival (native liver and LT) rate was 40%. Two of the four patients who had LT survived with a liver graft at 2 years.

Conclusions:  The 2‐year survival with native liver following corrective surgery for BA in UMMC, Malaysia, compares favourably with other international figures, but the overall survival rate was adversely affected by a lack of timely LT. The outcome of BA in Malaysia may be further improved by increasing the awareness among child‐health professionals on the importance early referral for appropriate surgery in infants suspected of having BA.
Single‐staged anterior and posterior spinal fusion: A safe and effective alternative for severe and rigid adolescent idiopathic scoliosis in China
Authors: Li Ming , Ni Jianqiang , Li Yang , Fang Xiutong , Gu Suxi , Zhang Zhiyu , Zhu Xiaodong
Published: April 2009

Aim:  Delayed treatment of adolescent idiopathic scoliosis (AIS) is common in Mainland China because of the lack of public education about health care resulting in the reluctance to undergo surgery. This leads to a high incidence of complex cases where surgeons may not be trained in advanced procedures. We report the efficacy of single‐staged anterior and posterior spinal fusion for correction of severe AIS in China.

Methods:  A retrospective review was performed of 31 consecutive cases in which patients were treated at the Orthopaedic Department of Changhai Hospital in Shanghai between 2001 and 2004 with a combined anterior and posterior spinal fusion with screws, hooks, sublaminar wires or cables.

Results:  Thirty‐one patients with AIS with Lenke type 1, 2, 3 and 4 curves were included for analysis. At least one of the curves was ≥90° in each patient. The mean coronal and sagittal Cobb angles of the main thoracic curve were 98° and 22° before surgery, 50.5° and 21° after surgery, and 53.7° and 24° at follow‐up, respectively. No neurological deficits or deaths occurred. Solid arthrodesis with coronal and sagittal balance was achieved in all patients.

Conclusions:  A single‐stage anterior release and fusion and posterior fusion for treatment of severe AIS is good alternative to pedicle screws/vertebrectomy on the basis of risk–benefit balance, and can be performed by surgeons not experienced in more complex procedures. The risk of pulmonary complications may be preferable to the risk of severe neurological complications when thoracic pedicle screws are applied, especially when surgeons are not adequately trained in their use.
Can parents accurately screen children at risk of developmental delay?
Authors: Dixon Glenys , Badawi Nadia , French Davina , Kurinczuk Jennifer J
Published: April 2009

Aim:  To evaluate the validity and potential value of the parent‐completed Infant/Child Monitoring Questionnaire (IMQ) as a screening measure for developmental delay in high‐risk infants.

Methods:  One hundred and forty‐one term infants born with moderate or severe newborn encephalopathy (NE) and 374 randomly selected comparison infants were administered a Griffiths Mental Development Scales (GMDS) assessment and an IMQ concurrently. Concordance of classifications between measures was compared for agreement, sensitivity, specificity, positive predictive value, negative predictive value, false positives and false negatives.

Results:  Overall, sensitivity and specificity of the IMQ for infants with NE averaged across all age groups was 87%, positive predictive value 57% and negative predictive value 97%. The IMQ did not perform as well for comparison infants with a sensitivity of 50%, specificity 94%, positive predictive value 15% and negative predictive value 99% averaged across all age groups. Overall under‐referral for infants with NE was 13%, compared with 50% for comparison infants.

Conclusions:  Use of the IMQ as an accurate screening measure in infants ‘at risk’ of developmental delay is supported. The low sensitivity of the IMQ for the comparison infants indicates a need for caution when considering its application for general population screening.
Promising outcomes of an adolescent chronic fatigue syndrome inpatient programme
Authors: Gordon Brett , Lubitz Lionel
Published: April 2009

Introduction:  Chronic fatigue syndrome (CFS) is a condition of prolonged and disabling fatigue, which is accompanied by characteristic constitutional and neuropsychiatric symptoms. In children and adolescents, this condition occurring at a developmentally vulnerable time adds to the disability affecting self‐concept, autonomy, body image, socialisation, sexuality and academic problems. This case series looks at the effects of a graded exercise programme on physical outcomes, fatigue and mental state in an adolescent population.

Methods:  Data sets from 16 adolescents who completed combined exercise training as part of the 4‐week inpatient intensive CFS programme at the Austin Hospital, Melbourne were analysed. All patients completed an exercise assessment and three questionnaires before beginning any training. A paediatrician (LL) confirmed the diagnosis according to the Fukuda criteria in all patients. Exercise was carefully supervised and prescribed daily by an exercise physiologist (BG) according to each individual's ability and response with the basic aim of increasing exercise tolerance and improving muscle strength and endurance.

Results:  There was an 18% improvement in volitional time to fatigue (P= 0.02) and 17% improvement in peak oxygen uptake (VO2peak) (P= 0.01). Upper body strength and function improved with a remarkable 70% increase in the number of push‐ups. Fatigue severity was reported to improve by 13% (P= 0.01) and depression index improved significantly by 42% (P= 0.02).

Conclusions:  The significance of these improvements cannot be underestimated as an improvement in physical capacity through increased time to fatigue and less severe fatigue allows adolescents to resume school, social and family activities.