bluuebunny/crossref_metadata_2025 huggingface dataset:
Geography, Informal Information Flows and Mutual Fund Portfolios
Authors: Fu Richard , Gupta‐Mukherjee Swasti
Published: October 2013

This paper explores how informal information channels impact mutual fund performance. We measure the strengths of two location‐based information channels: 1) information transfers among fund managers (fund‐fund links) and 2) transfers between managers and the companies in which they invest (fund‐company links). We find that each channel increases investment performance in the absence of the other, but decreases it when acting in combination. Stock selection associated with the presence of one channel, but the absence of the other, earns positive future returns. Our results indicate that the economic benefits of informal information channels depend critically on the nature of their interactions.
Fishers' targeting behaviour in Mediterranean: does vessel size matter?
Authors: Maravelias C. D. , Tsitsika E. V.
Published: October 2013

Fishers have a considerable knowledge about how fish stocks behave; knowledge that is difficult to acquire in other ways. Short‐term fisher tactics employed on trip by trip basis can change significantly due to their targeting behaviour, which in turn can lead to changes in catch composition and production output. A stochastic distance function was used to examine a Mediterranean pelagic fleet's technical efficiency and fishers' ability to modulate their targeting behaviour. The purse seine fleet operated under increasing returns to scale, suggesting that the larger vessels could potentially amplify their short‐term profitability by increasing the levels of inputs and harvests. Production was mainly joint, yet the possibility for limited substitution between species existed. The observed fishers' targeting behaviour was dissimilar between fleet segments due to differences in fishing effort and vessel characteristics, with larger vessels able to modify their revenue more than smaller ones. The estimated differences between the two fleet segments could be important in designing effective management regimes aimed at reducing resource overexploitation through individual input controls.
Effects of desiccation on native and non‐native molluscs in rivers
Authors: Collas Frank P. L. , Koopman K. Remon , Hendriks A. Jan , van der Velde Gerard , Verbrugge Laura N. H. , Leuven Rob S. E. W.
Published: October 2013

Laboratory data on desiccation tolerance of native and non‐native mollusc species were used to derive species sensitivity distributions (SSDs), to predict effects of desiccation on mollusc assemblages in rivers during low discharge events and to prioritise various environmental stressors (i.e. desiccation, temperature and salinity).

The predicted absence and observed absence of mollusc species by desiccation at a specific site were expressed as potentially not occurring fraction (PNOF) and not occurring fraction (NOF) of their regional species pool in the River Rhine.

Calculations of PNOFs for desiccation explained 57% (LT99) and 65% (LT50) of the NOFs of the mollusc species. Sensitivity to desiccation did not differ between native and non‐native mollusc species pools.

Due to differences in frequency of low river discharge events and water level fluctuations, mollusc species in an impounded reach of the River Meuse were less affected by desiccation than in a free‐flowing distributary of the River Rhine.

Earlier calculations of the PNOFs for combined effects of temperature and salinity in the River Rhine explained 22 and 3% of the NOFs of native and non‐native species, respectively, for the period 1988–2003. Accounting for the effects of desiccation, 62 and 80% of the NOFs of the native and non‐native species pool, respectively, were explained, indicating that desiccation during low discharge events was an important stressor in comparison with water temperature or salinity.

Since a relatively high percentage of the NOFs of native species in the River Rhine still remain unexplained, an effort to assess potential effects of other stressors is recommended (e.g. toxic substances or water turbulence caused by commercial shipping).
Increasing conspecific density weakens the ability of intermediate predators to develop induced morphological defences to top predators
Authors: Davenport Jon M. , Chalcraft David R.
Published: October 2013

Intraguild predation is common in nature, but it is unclear how species that both compete and eat each other can persist together. One possibility is that intermediate predators possess inducible morphological defences that protect them from top predators while not compromising their ability to compete with top predators.

The ability of intermediate predators to develop morphological defences may be compromised in environments with a high density of conspecifics because of reduced resource availability and predation risk due to the saturating functional response of top predators. Furthermore, since morphological defences take time to develop, the type and extent of morphological defences may vary during development.

We conducted an experiment to measure the phenotypic responses of an intermediate predator (larvae of the salamanderAmbystoma opacum) to the presence of a caged top predator (larvae of the dragonflyAnaxspp.) throughout ontological development in environments that differed in the density of conspecifics present. We also assessed how intermediate predators, reared in the different environments, differed in their vulnerability to top predators and ability to deplete their food resources.

We found thatAnaxinduced morphological defences inA. opacum, but the extent of morphological change declined with the density of conspecifics. Moreover, some morphological traits disappeared, while others appeared just prior toA. opacummetamorphosis. The change inA. opacumphenotype in response toAnaxmadeA. opacumless vulnerable to predation byAnaxbut had no significant effect on the foraging ability ofA. opacum.

Our study demonstrates that top predators can induce phenotypes in intermediate predators that reduce their vulnerability to top predators while not compromising their ability to feed on a common prey. An increase in intermediate predator density, however, could diminish the ability of intermediate predators to develop the full suite of morphological defences. The inability to develop the full suite of morphological defences may reduce the probability of persistence with top predators.
Digging deep for diversity: riparian seed bank abundance and species richness in relation to burial depth
Authors: O'Donnell Jessica , Fryirs Kirstie , Leishman Michelle R.
Published: October 2013

Soil and sediment seed banks contribute to the diversity of riparian plant communities. In degraded river systems, seed banks represent an important regeneration niche that may contribute to restoration efforts through the establishment of vegetation. The vertical dimension of seed banks has been neglected in river research, despite its importance for the regeneration of vegetation after disturbances such as erosive floods.

We sampled sediment at various depths within three geomorphological features: bars, benches and the floodplain, across four river reaches in the Wollombi subcatchment of New South Wales, Australia. A seedling emergence study was conducted to characterise the abundance and species richness of the germinable seed bank within these sediments. We hypothesised that the vertical distribution of seeds in bars and benches would show no clear pattern, but that bars would have lower propagule counts overall, due to their non‐cohesive sediment and potential for frequent reworking by low‐level flows. The floodplain seed bank, in contrast, would resemble that of terrestrial systems, with propagule abundance decreasing markedly with depth due to infrequent inundation and sediment reworking.

In total, 9456 seedlings emerged, representing 131 different species (83 native and 47 exotic) from 47 families. Propagule abundance and species richness in bar and bench seed banks were highly variable with depth, with the greatest average propagule numbers found at 25–30 cm and 20–25 cm, respectively. In contrast, and as hypothesised, propagule abundance and species richness in the floodplain decreased significantly with depth. Propagule abundance was surprisingly variable in bars, with some displaying extremely high values and others containing no detectable seeds, although overall species richness was significantly lower than in benches and the floodplain.

The vertical distribution of seeds in bars, benches and floodplains may be determined by the proportional influence of hydrochory (seed transport and deposition by water) during deposition events and seed losses, resulting from sediment reworking and erosion, set within the timescales over which they are formed and reworked. Bar seed banks are continually flushed by frequent inundation and reworking, especially at the surface, reducing seed deposition and burial. Abundant seed fall may be provided by local vegetation, however. Diverse seed banks in benches may form through alternating periods of hydrochoric seed deposition along with sediment, augmented during periods of exposure when propagules from the extant vegetation accumulate. Decreases in germinable propagule abundance and species richness with depth in the floodplain may reflect much slower rates of vertical accretion and seed losses due to mortality over time. Finally, we present some implications for the management of riparian vegetation and applications for river restoration.
Global warming enhances sulphide stress in a key seagrass species (NW Mediterranean)
Authors: García Rosa , Holmer Marianne , Duarte Carlos M. , Marbà Núria
Published: October 2013

The build‐up of sulphide concentrations in sediments, resulting from high inputs of organic matter and the mineralization through sulphate reduction, can be lethal to the benthos. Sulphate reduction is temperature dependent, thus global warming may contribute to even higher sulphide concentrations and benthos mortality. The seagrassPosidonia oceanicais very sensitive to sulphide stress. Hence, if concentrations build up with global warming, this key Mediterranean species could be seriously endangered. An 8‐year monitoring of daily seawater temperature, the sulphur isotopic signatures of water (δ34Swater), sediment(δ34SCRS) andP. oceanicaleaf tissue(δ34Sleaves), along with total sulphur in leaves (TSleaves) and annual net population growth along the coast of the Balearic archipelago (Western Mediterranean) allowed us to determine if warming triggersP. oceanicasulphide stress and constrains seagrass survival. From the isotopicSsignatures, we estimated sulphide intrusion into the leaves (Fsulphide) and sulphur incorporation into the leaves from sedimentary sulphides (SSleaves). We observed lowerδ34Sleaves, higherFsulphideandSSleavescoinciding with a 6‐year period when two heat waves were recorded. Warming triggered sulphide stress as evidenced by the negative temperature dependence ofδ34Sleavesand the positive one ofFsulphide,TSleavesandSSleaves. LowerP. oceanicanet population growth rates were directly related to higher contents ofTSleaves. At equivalent annual maximum sea surface water temperature (SSTmax), deep meadows were less affected by sulphide intrusion than shallow ones. Thus, water depth acts as a protecting mechanism against sulphide intrusion. However, water depth would be insufficient to buffer seagrass sulphide stress triggered by Mediterranean seawater summer temperatures projected for the end of the 21st century even under scenarios of moderate greenhouse gas emissions, A1B. Mediterranean warming, therefore, is expected to enhanceP. oceanicasulphide stress, and thus compromise the survival of this key habitat along its entire depth distribution range.
Separating direct and indirect effects of global change: a population dynamic modeling approach using readily available field data
Authors: Farrer Emily C. , Ashton Isabel W. , Knape Jonas , Suding Katharine N.
Published: October 2013

Two sources of complexity make predicting plant community response to global change particularly challenging. First, realistic global change scenarios involve multiple drivers of environmental change that can interact with one another to produce non‐additive effects. Second, in addition to these direct effects, global change drivers can indirectly affect plants by modifying species interactions. In order to tackle both of these challenges, we propose a novel population modeling approach, requiring only measurements of abundance and climate over time. To demonstrate the applicability of this approach, we model population dynamics of eight abundant plant species in a multifactorial global change experiment in alpine tundra where we manipulated nitrogen, precipitation, and temperature over 7 years. We test whether indirect and interactive effects are important to population dynamics and whether explicitly incorporating species interactions can change predictions when models are forecast under future climate change scenarios. For three of the eight species, population dynamics were best explained by direct effect models, for one species neither direct nor indirect effects were important, and for the other four species indirect effects mattered. Overall, global change had negative effects on species population growth, although species responded to different global change drivers, and single‐factor effects were slightly more common than interactive direct effects. When the fitted population dynamic models were extrapolated under changing climatic conditions to the end of the century, forecasts of community dynamics and diversity loss were largely similar using direct effect models that do not explicitly incorporate species interactions or best‐fit models; however, inclusion of species interactions was important in refining the predictions for two of the species. The modeling approach proposed here is a powerful way of analyzing readily available datasets which should be added to our toolbox to tease apart complex drivers of global change.
The seasonal timing of warming that controls onset of the growing season
Authors: Clark James S. , Melillo Jerry , Mohan Jacqueline , Salk Carl
Published: October 2013

Forecasting how global warming will affect onset of the growing season is essential for predicting terrestrial productivity, but suffers from conflicting evidence. We show that accurate estimates require ways to connect discrete observations of changing tree status (e.g., pre‐ vs. post budbreak) with continuous responses to fluctuating temperatures. By coherently synthesizing discrete observations with continuous responses to temperature variation, we accurately quantify how increasing temperature variation accelerates onset of growth. Application to warming experiments at two latitudes demonstrates that maximum responses to warming are concentrated in late winter, weeks ahead of the main budbreak period. Given that warming will not occur uniformly over the year, knowledge of when temperature variation has the most impact can guide prediction. Responses are large and heterogeneous, yet predictable. The approach has immediate application to forecasting effects of warming on growing season length, requiring only information that is readily available from weather stations and generated in climate models.
Replicated throughfall exclusion experiment in an Indonesian perhumid rainforest: wood production, litter fall and fine root growth under simulated drought
Authors: Moser Gerald , Schuldt Bernhard , Hertel Dietrich , Horna Viviana , Coners Heinz , Barus Henry , Leuschner Christoph
Published: October 2013

Climate change scenarios predict increases in the frequency and duration of ENSO‐related droughts for parts of South‐East Asia until the end of this century exposing the remaining rainforests to increasing drought risk. A pan‐tropical review of recorded drought‐related tree mortalities in more than 100 monitoring plots before, during and after drought events suggested a higher drought‐vulnerability of trees in South‐East Asian than in Amazonian forests. Here, we present the results of a replicated (n = 3 plots) throughfall exclusion experiment in a perhumid tropical rainforest in Sulawesi, Indonesia. In this first large‐scale roof experiment outside semihumid eastern Amazonia, 60% of the throughfall was displaced during the first 8 months and 80% during the subsequent 17 months, exposing the forest to severe soil desiccation for about 17 months. In the experiment's second year, wood production decreased on average by 40% with largely different responses of the tree families (ranging from −100 to +100% change). Most sensitive were trees with high radial growth rates under moist conditions. In contrast, tree height was only a secondary factor and wood specific gravity had no influence on growth sensitivity. Fine root biomass was reduced by 35% after 25 months of soil desiccation while fine root necromass increased by 250% indicating elevated fine root mortality. Cumulative aboveground litter production was not significantly reduced in this period. The trees from this Indonesian perhumid rainforest revealed similar responses of wood and litter production and root dynamics as those in two semihumid Amazonian forests subjected to experimental drought. We conclude that trees from paleo‐ or neotropical forests growing in semihumid or perhumid climates may not differ systematically in their growth sensitivity and vitality under sublethal drought stress. Drought vulnerability may depend more on stem cambial activity in moist periods than on tree height or wood specific gravity.
Elevation‐induced climate change as a dominant factor causing the late Miocene C4 plant expansion in the Himalayan foreland
Authors: Wu Haibin , Guo Zhengtang , Guiot Joël , Hatté Christine , Peng Changhui , Yu Yanyan , Ge Junyi , Li Qin , Sun Aizhi , Zhao Deai
Published: October 2013

During the late Miocene, a dramatic global expansion of C4 plant distribution occurred with broad spatial and temporal variations. Although the event is well documented, whether subsequent expansions were caused by a decreased atmospheric CO2 concentration or climate change is a contentious issue. In this study, we used an improved inverse vegetation modeling approach that accounts for the physiological responses of C3 and C4 plants to quantitatively reconstruct the paleoclimate in the Siwalik of Nepal based on pollen and carbon isotope data. We also studied the sensitivity of the C3 and C4 plants to changes in the climate and the atmospheric CO2 concentration. We suggest that the expansion of the C4 plant distribution during the late Miocene may have been primarily triggered by regional aridification and temperature increases. The expansion was unlikely caused by reduced CO2 levels alone. Our findings suggest that this abrupt ecological shift mainly resulted from climate changes related to the decreased elevation of the Himalayan foreland.
Biochar amendment to soils with contrasting organic matter level: effects on N mineralization and biological soil properties
Authors: Ameloot Nele , Sleutel Steven , Das K. C. , Kanagaratnam Jegajeevagan , de Neve Stefaan
Published: October 2013

Four biochar types, produced by slow pyrolysis of poultry litter (PL) and pine chips (P) at 400 or 500 °C, were added to two adjacent soils with contrasting soil organic matter (SOM) content (8.9 vs. 16.1 g C kg−1). The N mineralization rate was determined during 14‐week incubations and assessments were made of the microbial biomass C, dehydrogenase activity, and the microbial community structure (PLFA‐extraction). The addition of PL biochars increased the net N mineralization (i.e., compared to the control treatment) in both soils, while for treatments with P biochars net N immobilization was observed in both soils. Increasing the pyrolysis temperature of both feedstock types led to a decrease in net N mineralization. The ratio of Bacterial to Fungal PLFA biomarkers also increased with addition of biochars, and particularly in the case of the 500 °C biochars. Next to feedstock type and pyrolysis temperature, SOM content clearly affected the assessed soil biological parameters, viz. net N mineralization or immobilization, MBC and dehydrogenase activity were all greater in the H soil. This might be explained by an increased chance of physical contact between the microbial community activated by SOM mineralization upon incubation and discrete biochar particles. However, when considering the H soil's double C and N content, these responses were disproportionally small, which may be partly due to the L soil's, somewhat more labile SOM. Nonetheless, increasing SOM content and microbial biomass and activity generally appears to result in greater mineralization of biochar. Additionally, higher N mineralization after PL addition to the H soil with lower pH than the L soil can be due to the liming effect of the PL biochars.
Effects of harvest frequency and biosolids application on switchgrass yield, feedstock quality, and theoretical ethanol yield
Authors: Liu Xiao‐Jun Allen , Fike John H. , Galbraith John M. , Fike Wonae B. , Parrish David J. , Evanylo Gregory K. , Strahm Brian D.
Published: October 2013

Sustainable development of a bioenergy industry will require low‐cost, high‐yielding biomass feedstock of desirable quality. Switchgrass (Panicum virgatum L.) is one of the primary feedstock candidates in North America, but the potential to grow this biomass crop using fertility from biosolids has not been fully explored. The objective of this study was to examine the effects of harvest frequency and biosolids application on switchgrass in Virginia, USA. ‘Cave‐in‐Rock’ switchgrass from well‐established plots was cut once (November) or twice (July and November) per year between 2010 and 2012. Class A biosolids were applied once at rates of 0, 153, 306, and 459 kg N ha−1 in May 2010. Biomass yield, neutral and acid detergent fiber, cellulose, hemicellulose, lignin, and ash were determined. Theoretical ethanol potential (TEP, l ethanol Mg−1 biomass) and yield (TEY, l ethanol ha−1) were calculated based on cellulose and hemicellulose concentrations. Cutting twice per season produced greater biomass yields than one cutting (11.7 vs. 9.8 Mg ha−1) in 2011, but no differences were observed in other years. Cutting once produced feedstock with greater TEP (478 vs. 438 l Mg−1), but no differences in TEY between cutting frequencies. Biosolids applied at 153, 306, and 459 kg N ha−1 increased biomass yields by 25%, 37%, and 46%, and TEY by 25%, 34%, and 42%, respectively. Biosolids had inconsistent effects on feedstock quality and TEP. A single, end‐of‐season harvest likely will be preferred based on apparent advantages in feedstock quality. Biosolids can serve as an effective alternative to N fertilizer in switchgrass‐to‐energy systems.
Influence of intraspecific competition on the distribution of a wide‐ranging, non‐territorial carnivore
Authors: Pilfold Nicholas W. , Derocher Andrew E. , Richardson Evan
Published: October 2013

Aim

It is generally held that the dominant competitors in a population will occupy high‐quality habitat while forcing subordinates into lower‐quality habitats through interference competition. We examined the distribution of a non‐territorial apex carnivore relative to foraging habitat to assess the effect of two types of interference: competitive asymmetries in predatory ability and conspecific predation risk.

Location

Beaufort Sea, Canada.

Methods

The quality of foraging habitat was modelled using resource selection functions to relate the locations of seals killed by polar bears (Ursus maritimus) to attributes of the sea ice. We used estimated seal biomass as a sample weight to reflect the energetic return of different sizes of kills. To test the effect of sample weighting, locations at which polar bears were captured were used to compare habitat quality modelled with kills weighted equally and kills weighted by their biomass. The distributions of different demographic classes of polar bears were then compared with the general predictions of unequal‐competitor models.

Results

Polar bear distribution was correlated with the quality of the foraging habitat as determined by the kill biomass model (rs = 0.90, P = 0.04), but not in the unweighted design (P = 0.75). No difference was detected in use of the highest‐quality foraging habitat by subadults and adults. Females with cubs‐of‐the‐year used lower‐quality foraging habitat relative to the rest of the population.

Main conclusions

Weighting the habitat model with biologically relevant information improved its fit to species distribution, and suggested that density of use alone was insufficient to define habitat quality. Intraspecific competition had a varying influence on the distribution: unequal competitors coexisted, while the avoidance of conspecific predation risk resulted in semi‐truncation.
A meta‐analysis comparing standard polyethylene and oxygen barrier film in terms of losses during storage and aerobic stability of silage
Authors: Wilkinson J. M. , Fenlon J. S.
Published: October 2013

A meta‐analysis was undertaken of 51 comparisons of standard polyethylene film with oxygen barrier (OB) film in covering systems for bunker silos, unwalled clamp silos and bales. Mean losses of DM or OM during storage from the top 10 to 60 cm of bunker and clamp silos were 195 g kg−1 for standard film and 114 g kg−1 for OB film systems (41 sets of data, P < 0·001), while mean total losses of DM from baled silage were 76·8 g kg−1 for standard film and 45·6 g kg−1 for OB film systems (10 sets of data, P < 0·001). Top surface silage judged subjectively to be inedible was 107 and 29·6 g kg−1 for standard film and OB film systems respectively (5 sets of data, P = 0·02). Aerobic stability was 75 h for silage stored under standard film system and 135 h for silage stored under OB film system (11 sets of data, P = 0·001). It is concluded that the OB film system reduces losses from the outer layers of silos and from bales and increases the aerobic stability of silage in the outer layers of silos.
Self‐reported quality of sleep is associated with bodily pain, vitality and cognitive impairment in Japanese older adults
Authors: Sampaio Ricardo Aurélio Carvalho , Sewo Sampaio Priscila Yukari , Yamada Minoru , Tsuboyama Tadao , Arai Hidenori
Published: October 2013

Aim

Poor sleep can affect physical and mental health, and consequently people's quality of life (QOL); however, only a few studies have addressed the potential associations of physical and mental health with quality of sleep (QOS) in Japan. The present study aimed to investigate the association of QOS with sociodemographic and lifestyle characteristics, cognitive status, nutrition, depression, seclusion, and QOL in Japanese community‐dwelling older adults.

Methods

Data were collected through self‐administered questionnaires and other specific tests in 145 (age 73 years [range 70–77 years]) participants. The χ2‐test or Fisher's exact test were used to compare categorical variables stratified by QOS, and the Mann–Whitney U‐test was used for continuous variables. Furthermore, logistic regression analyses were carried out to verify the associations with QOS.

Results

The poor QOS group had more males (P < 0.05), a shorter self‐reported sleep duration (P < 0.001), higher body mass index (P < 0.05) and higher risk of depression (P < 0.05), whereas the good QOS group showed higher scores in the QOL summary and domains of physical component (P < 0.01), general health (P < 0.001), bodily pain (P < 0.001) and vitality (P < 0.001). In the logistic regression model, cognitive status (OR 0.13, 95% CI 0.03–0.55), bodily pain (OR 0.91, 95% CI 0.84–1.00) and vitality (OR 0.82, 95% CI 0.73–0.92) were associated with QOS.

Conclusion

The present study provides evidence that QOS is linked to cognitive status, bodily pain and vitality in Japanese older adults. We maintain that screening a person's sleep characteristics in a community setting might be relevant to identify those older adults at risk of a poor QOL and frailty in the early phase, triggering further health analyses. Geriatr Gerontol Int 2014; 14: 628–635.
Principal component analysis of odor coding at the level of third‐order olfactory neurons in Drosophila
Authors: Hiroi Makoto , Ohkura Masamichi , Nakai Junichi , Masuda Naoki , Hashimoto Koichi , Inoue Kiichi , Fiala André , Tabata Tetsuya
Published: October 2013

Olfactory information in Drosophila is conveyed by projection neurons from olfactory sensory neurons to Kenyon cells (KCs) in the mushroom body (MB). A subset of KCs responds to a given odor molecule, and the combination of these KCs represents a part of the neuronal olfactory code. KCs are also thought to function as coincidence detectors for memory formation, associating odor information with a coincident punishment or reward stimulus. Associative conditioning has been shown to modify KC output. This plasticity occurs in the vertical lobes of MBs containing α/α' branches of KCs, which is shown by measuring the average Ca2+ levels in the branch of each lobe. We devised a method to quantitatively describe the population activity patterns recorded from axons of >1000 KCs at the α/α' branches using two‐photon Ca2+ imaging. Principal component analysis of the population activity patterns clearly differentiated the responses to distinct odors.
Verification of the in vivo activity of three distinct cis‐acting elements within the Gata1 gene promoter‐proximal enhancer in mice
Authors: Shimizu Ritsuko , Hasegawa Atsushi , Ottolenghi Sergio , Ronchi Antonella , Yamamoto Masayuki
Published: October 2013

The transcription factor GATA1 is essential for erythroid and megakaryocytic cell differentiation. Gata1 hematopoietic regulatory domain (G1HRD) has been shown to recapitulate endogenous Gata1 gene expression in transgenic mouse assays in vivo. G1HRD contains a promoter‐proximal enhancer composed of a GATA‐palindrome motif, four CP2‐binding sites and two CACCC boxes. We prepared transgenic reporter mouse lines in which green fluorescent protein and β‐galactosidase expression are driven by wild‐type G1HRD (as a positive control) and the G1HRD harboring mutations within these cis‐acting elements (as the experimental conditions), respectively. Exploiting this transgenic dual reporter (TDR) assay, we show here that in definitive erythropoiesis, G1HRD activity was markedly affected by individual mutations in the GATA‐palindrome motif and the CACCC boxes. Mutation of CP2‐binding sites also moderately decreased G1HRD activity. The combined mutation of the CP2‐binding sites and the GATA‐palindrome motif resulted in complete loss of G1HRD activity. In contrast, in primitive erythroid cells, individual mutations of each element did not affect G1HRD activity; G1HRD activity was abolished only when these three mutations were combined. These results thus show that all three elements independently and cooperatively contribute to G1HRD activity in vivo in definitive erythropoiesis, although these are contributing redundantly to primitive erythropoiesis.
Contributing Factors to Disease Outbreaks Associated with Untreated Groundwater
Authors: Wallender Erika K. , Ailes Elizabeth C. , Yoder Jonathan S. , Roberts Virginia A. , Brunkard Joan M.
Published: October 2013

Disease outbreaks associated with drinking water drawn from untreated groundwater sources represent a substantial proportion (30.3%) of the 818 drinking water outbreaks reported to CDC's Waterborne Disease and Outbreak Surveillance System (WBDOSS) during 1971 to 2008. The objectives of this study were to identify underlying contributing factors, suggest improvements for data collection during outbreaks, and inform outbreak prevention efforts. Two researchers independently reviewed all qualifying outbreak reports (1971 to 2008), assigned contributing factors and abstracted additional information (e.g., cases, etiology, and water system attributes). The 248 outbreaks resulted in at least 23,478 cases of illness, 390 hospitalizations, and 13 deaths. The majority of outbreaks had an unidentified etiology (n = 135, 54.4%). When identified, the primary etiologies were hepatitis A virus (n = 21, 8.5%), Shigella spp. (n = 20, 8.1%), and Giardia intestinalis (n = 14, 5.7%). Among the 172 (69.4%) outbreaks with contributing factor data available, the leading contamination sources included human sewage (n = 57, 33.1%), animal contamination (n = 16, 9.3%), and contamination entering via the distribution system (n = 12, 7.0%). Groundwater contamination was most often facilitated by improper design, maintenance or location of the water source or nearby waste water disposal system (i.e., septic tank; n = 116, 67.4%). Other contributing factors included rapid pathogen transport through hydrogeologic formations (e.g., karst limestone; n = 45, 26.2%) and preceding heavy rainfall or flooding (n = 36, 20.9%). This analysis underscores the importance of identifying untreated groundwater system vulnerabilities through frequent inspection and routine maintenance, as recommended by protective regulations such as Environmental Protection Agency's (EPA's) Groundwater Rule, and the need for special consideration of the local hydrogeology.
Factor XIII deficiency: complete phenotypic characterization of two cases with novel causative mutations
Authors: Katona É. , Muszbek L. , Devreese K. , Kovács K. B. , Bereczky Z. , Jonkers M. , Shemirani A. H. , Mondelaers V. , Ermens A. A. M.
Published: October 2013

Coagulation factor XIII (FXIII) exists as heterotetramer (FXIII‐A2B2) in the plasma and as dimer (FXIII‐A2) in cells. Activated FXIII mechanically stabilizes fibrin and protects it from fibrinolysis by cross‐linking fibrin chains and α2‐plasmin inhibitor to fibrin. FXIII is essential to maintaining haemostasis, and its deficiency causes severe bleeding diathesis. Due to improper laboratory practices, FXIII deficiency is considered the most under‐diagnosed bleeding disorder. The aim of this study was to demonstrate in two cases how FXIII deficiency is properly diagnosed and classified, and to compare results of laboratory analysis and clinical symptoms. FXIII activity from plasma and platelets was measured by a modified ammonia release assay, while FXIII‐A2B2, FXIII‐A and FXIII‐B antigens were determined by ELISA. The exon–intron boundaries and the promoter region of F13A1 gene were amplified by PCR and the amplified products were analysed by direct fluorescent sequencing. FXIII‐A mRNA in platelets was determined by RT‐qPCR. Two children with severe bleeding symptoms were investigated. In both cases FXIII activity and FXIII‐A antigen were undetectable in the plasma and platelet lysate. In the plasma no FXIII‐A2B2 antigen was found, while FXIII‐B antigen was >30% in both cases. Proband1 was a compound heterozygote possessing a known missense mutation (c.980G>A, p.Arg326Gln) and a novel splice–site mutation (c.1112+2T>C). Proband2 was homozygote for a novel single nucleotide deletion (c.212delA) leading to early stop codon. The discovered mutations explain the severity of clinical symptoms and the laboratory data. Methods precise in the low activity/antigen range are required to draw valid conclusion on phenotype–genotype relationship.
Correlates of ADL difficulty in a large hemodialysis cohort
Authors: Kutner Nancy G. , Zhang Rebecca , Allman Richard M. , Bowling C. Barrett
Published: October 2013

Needing assistance with activities of daily living (ADL) is an early indicator of functional decline and has important implications for individuals' quality of life. However, correlates of need for ADL assistance have received limited attention among patients undergoing maintenance hemodialysis (HD). A multicenter cohort of 742 prevalent HD patients was assessed in 2009–2011 and classified as frail, prefrail and nonfrail by the Fried frailty index (recent unintentional weight loss, reported exhaustion, low grip strength, slow walk speed, low physical activity). Patients reported need for assistance with 4 ADL tasks and identified contributing symptoms/conditions (pain, balance, endurance, weakness, others). Nearly 1 in 5 patients needed assistance with 1 or more ADL. Multivariable analysis showed increased odds for needing ADL assistance among frail (odds ratio [OR] 11.35; 95% confidence interval [CI] 5.50–23.41; P < 0.001) and prefrail (OR 1.93; 95% CI 1.01–3.68; P = 0.046) compared with non‐frail patients. In addition, the odds for needing ADL assistance were lower among blacks compared with whites and were higher among patients with diabetes, lung disease, and stroke. Balance, weakness, and “other” (frequently dialysis‐related) symptoms/conditions were the most frequently named reasons for ADL difficulty. In addition to interventions such as increasing physical activity that might delay or reverse the process of frailty, the immediate symptoms/conditions to which individuals attribute their ADL difficulty may have clinical relevance for developing targeted management and/or treatment approaches.
Plasma cell hepatitis induced by the termination of antiviral therapy for recurrent hepatitis C after living donor liver transplantation
Authors: Ueda Yoshihide , Yoshizawa Atsushi , Ogura Yasuhiro , Miyagawa‐Hayashino Aya , Haga Hironori , Chiba Tsutomu , Uemoto Shinji
Published: October 2013

Plasma cell hepatitis (PCH) is an idiopathic disorder characterized by plasma cell infiltration in the allografts of patients who have undergone liver transplantation. Although an increasing number of cases of PCH have been reported in liver transplant recipients with hepatitis C recurrence treated with interferon, it is unclear whether PCH is induced by interferon itself. Here, we describe the cases of two patients who developed PCH just after the termination of antiviral therapy for recurrent hepatitis C after living donor liver transplantation. Liver dysfunction appeared at 1 month in one patient and 2 months in the other patient after pegylated interferon plus ribavirin therapy, and liver histology showed interface hepatitis with plasma cell‐rich lymphoid aggregates. Both patients recovered after steroid therapy and achieved sustained virological response. These cases suggest that PCH could be induced by the alteration of the immune condition resulting from the termination of antiviral therapy. PCH should be considered when the transaminase levels increase after antiviral therapy, and it should be carefully distinguished from hepatitis C relapse.
Hepatic molecular effects of rosiglitazone in human non‐alcoholic steatohepatitis suggest long‐term pro‐inflammatory damage
Authors: Lemoine Maud , Serfaty Lawrence , Cervera Pascale , Capeau Jacqueline , Ratziu Vlad
Published: October 2013

Aim

Glitazones are agonists of peroxisome proliferator‐activated receptor‐γ (PPAR‐γ) and have been proposed for the treatment of non‐alcoholic steatohepatitis (NASH). However, efficacy results are conflicting and hepatic molecular changes induced by glitazones are mostly unknown. The aim of this study was to analyze the hepatic inflammatory and fibrogenic molecular effects of rosiglitazone in NASH patients.

Methods

Hepatic expression of PPAR‐γ and several inflammatory/immune and fibrogenic genes were studied before and after a 12‐month treatment with rosiglitazone or placebo in 25 patients with NASH from the Fatty Liver Improvement with Rosiglitazone Therapy (FLIRT) trial.

Results

Treatment with rosiglitazone induced hepatic PPAR‐γ expression but increased the expression of several pro‐inflammatory genes such as SOCS3 and TLR4. There was a significant reduction in mRNA and protein levels of α‐smooth muscle actin, compatible with previously documented antifibrotic actions of rosiglitazone on stellate cells. However, there was no change in type 1 collagen and transforming growth factor‐β expression thus suggesting an offset of the antifibrogenic actions by long‐term pro‐inflammatory changes.

Conclusion

In NASH patients, hepatic PPAR‐γ induction by rosiglitazone was associated with increased hepatic expression of pro‐inflammatory genes which may explain the lack of long‐term histological benefit shown in human studies with this drug. It is unclear whether these results are a class effect of PPAR‐γ agonists or a specific effect of rosiglitazone.
Diameters of left gastric vein and its originating vein on magnetic resonance imaging in liver cirrhosis patients with hepatitis B: Association with endoscopic grades of esophageal varices
Authors: Zhou Hai‐ying , Chen Tian‐wu , Zhang Xiao‐ming , Zeng Nan‐lin , Zhou Li , Tang Hong‐jie , Wang Dan , Jian Su , Liao Juan , Xiang Jun‐ying , Hu Jiani , Zhang Zishu
Published: October 2013

Aim

To determine whether diameters of the left gastric vein (LGV) and its originating vein are associated with endoscopic grades of esophageal varices.

Methods

Ninety‐eight liver cirrhotic patients with hepatitis B undergoing magnetic resonance (MR) portography, and upper gastrointestinal endoscopy for grading esophageal varices were enrolled. Diameters of the LGV and its originating vein – the splenic vein (SV) or portal vein (PV) – were measured on MR imaging. Statistical analyses were performed to identify the association of the diameters with the endoscopic grades.

Results

Univariate analysis showed that the SV was predominantly the originating vein of the LGV, and diameters of the LGV and SV were associated with grades of esophageal varices. Diameters of the LGV (P = 0.023, odds ratio [OR] = 1.583) and SV (P = 0.012, OR = 2.126) were independent risk factors of presence of the varices. Cut‐off LGV diameters of 5.1 mm, 5.9 mm, 6.6 mm, 7.1 mm, 7.8 mm and 5.8 mm; or cut‐off SV diameters of 7.3 mm, 7.9 mm, 8.4 mm, 9.5 mm, 10.7 mm and 8.3 mm, could discriminate grades 0 from 1, 0 from 2, 0 from 3, 1 from 3, 2 from 3, and 0–1 from 2–3, respectively.

Conclusion

Diameters of the LGV and SV are associated with endoscopic grades of esophageal varices.
Hepatic oxidative stress in ovariectomized transgenic mice expressing the hepatitis C virus polyprotein is augmented through suppression of adenosine monophosphate‐activated protein kinase/proliferator‐activated receptor gamma co‐activator 1 alpha signaling
Authors: Tomiyama Yasuyuki , Nishina Sohji , Hara Yuichi , Kawase Tomoya , Hino Keisuke
Published: October 2013

Aim

Oxidative stress plays an important role in hepatocarcinogenesis of hepatitis C virus (HCV)‐related chronic liver diseases. Despite the evidence of an increased proportion of females among elderly patients with HCV‐related hepatocellular carcinoma (HCC), it remains unknown whether HCV augments hepatic oxidative stress in postmenopausal women. The aim of this study was to determine whether oxidative stress was augmented in ovariectomized (OVX) transgenic mice expressing the HCV polyprotein and to investigate its underlying mechanisms.

Methods

OVX and sham‐operated female transgenic mice expressing the HCV polyprotein and non‐transgenic littermates were assessed for the production of reactive oxygen species (ROS), expression of inflammatory cytokines and antioxidant potential in the liver.

Results

Compared with OVX non‐transgenic mice, OVX transgenic mice showed marked hepatic steatosis and ROS production without increased induction of inflammatory cytokines, but there was no increase in ROS‐detoxifying enzymes such as superoxide dismutase 2 and glutathione peroxidase 1. In accordance with these results, OVX transgenic mice showed less activation of peroxisome proliferator‐activated receptor‐γ co‐activator‐1α (PGC‐1α), which is required for the induction of ROS‐detoxifying enzymes, and no activation of adenosine monophosphate‐activated protein kinase‐α (AMPKα), which regulates the activity of PGC‐1α.

Conclusion

Our study demonstrated that hepatic oxidative stress was augmented in OVX transgenic mice expressing the HCV polyprotein by attenuation of antioxidant potential through inhibition of AMPK/PGC‐1α signaling. These results may account in part for the mechanisms by which HCV‐infected women are at high risk for HCC development when some period has passed after menopause.
Correlation between tuberous sclerosis complex 2 and glycogen synthase kinase 3 beta levels, and outcomes of patients with hepatocellular carcinoma treated by hepatectomy
Authors: Huang Ka‐Te , Huang Yue‐Han , Li Peng , He Bin , Chen Zhen‐Kun , Yu Xia , Chen Jian‐Ou , Zhang Qi‐Yu , Shi Hong‐Qi , Shan Yun‐Feng
Published: October 2013

Aim

Tuberous sclerosis complex 2 (TSC2), a tumor suppressor, may play an essential role in the regulation of cell growth and cell survival under energy stress conditions. In addition, TSC2 may act in concert with Wnt and energy signals by additional phosphorylation of glycogen synthase kinase 3β (GSK3β) to regulate cell growth. The expression levels and function of TSC2 and GSK3β in hepatocellular carcinoma (HCC) remain unclear.

Methods

The protein levels of TSC2 and GSK3β were measured by immunohistochemistry in normal liver (n = 20), HCC (n = 80) and pericancerous tissues (n = 80). The correlations between TSC2, and GSK3β levels, clinicopathological features and patient survival were also analyzed.

Results

The protein levels of TSC2 and GSK3β in HCC tissues were significantly lower than that in normal liver tissues and pericancerous tissues (P < 0.05). Decreased TSC2 and GSK3β expression was found to be significantly correlated with advanced clinicopathological characteristics and poor prognosis. The results also showed that TSC2 protein levels were associated with GSK3β expression in HCC specimens.

Conclusion

This is the first demonstration that the decreases in TSC2 and GSK3β levels may be associated with vascular invasion, histological grade and tumor–node–metastasis classification.
Joint replacement recipients' views about health information privacy
Authors: Terry Amanda L. , Chesworth Bert M. , Bourne Robert B. , Stolee Paul , Speechley Mark
Published: October 2013

Background

Researchers are concerned about the possibility of restricted access to data as a result of specific consent requirements in privacy legislation, potentially resulting in smaller samples and a lack of representativeness which could bias results. In addition, there is uncertainty about what influences individuals to give consent for the use of their personal health information.

Objective

To measure joint replacement recipients' health information privacy views and to assess potential predictors of these views.

Design

Cross‐sectional survey.

Setting and participants

Potential joint replacement recipients from two teaching hospitals in London, Ontario, Canada.

Main variables

Age, gender, education, employment status, anticipated joint replacement, and expectations for surgery.

Main outcome measures

Privacy concerns as measured by the Concern Scale.

Results

The response rate was 182/253 or 72%. The mean Concern score was 143.9/235.0 for the total sample (range = 82–216). Women had higher levels of privacy concerns than men on slightly over half of the individual questionnaire items. In women, surgical joint, age and employment explained 15% of the variance in concerns about personal health information privacy (P = 0.001). The model explained 6% of the variance in concerns in men (P = 0.138) and was not statistically significant.

Discussion and conclusion

This study indicates that demographic characteristics and health‐care experiences play a role in the variability of health information privacy concerns. A greater understanding of patients' privacy views about health information could lead to a greater harmonization among privacy rules, research and data access, and the preferences of health‐care consumers.