bluuebunny/crossref_metadata_2025 huggingface dataset:
Habitat preferences of striped marlin (Kajikia audax) in the eastern Pacific Ocean
Authors: Acosta‐Pachón Tatiana A. , Martínez‐Rincón Raúl O. , Hinton Michael G.
Published: April 2017

Striped marlin (Kajikia audax) is an epipelagic species distributed in tropical and temperate waters of the Pacific Ocean. In the central and eastern Pacific Ocean, it is captured principally in commercial longline fisheries, and in small artisanal fisheries, however, it is also taken throughout its range in this region as an incidental catch of the tuna purse‐seine fishery. Previous studies suggest that overexploitation and climate change may reduce abundance and cause changes in spatial distributions of marine species. The main objective of this study was to describe the habitat preferences of striped marlin and the changes in its distribution in response to environmental factors. Habitat modeling was conducted using a maximum entropy model. Operational level data for 2003–2014, collected by scientific observers aboard large purse seine vessels, were compiled by the Inter‐American Tropical Tuna Commission and were matched with detailed (4 km) oceanographic data from satellites and general circulation models. Results showed that the spatial distribution of habitat was dynamic, with seasonal shifts between coastal (winter) and oceanic (summer) waters. We found that the preferred habitat is mainly in coastal waters with warm sea surface temperatures and a high chlorophyll‐a concentration.
Patterns on a parr: Drivers of long‐term salmon parr length in U.K. and French rivers depend on geographical scale
Authors: Gregory Stephen D. , Nevoux Marie , Riley William D. , Beaumont William R. C. , Jeannot Nicholas , Lauridsen Rasmus B. , Marchand Frederic , Scott Luke J. , Roussel Jean‐Marc
Published: April 2017

Understanding the geographical scales at which environmental variables affect an individual's body size, and thus their mortality risk, can inform management strategies to help conserve wild populations under climate change. Yet, our current understanding of these relationships is based on studies done at different scales that report inconsistent findings. We predicted that temperature‐related variables (e.g. winter temperature) influence body size at a “regional” scale, that is, affecting individuals in geographically independent catchments similarly, whereas non‐temperature‐related variables (e.g. conspecific competitor density) exert a “local” influence, that is, affecting individuals in geographically independent catchments differently.

We developed statistical models to test our predictions using body length measures of a large and long‐term sample of juvenile Atlantic salmon (Salmo salar) from three rivers in the U.K. and France. We developed mixture models to predict the individual juvenile salmon ages objectively from their body length. We then developed linear mixed models to describe inter‐annual changes in mean length of the youngest (age 0) cohort of juvenile salmon from river‐specific seasonal variables, and tested whether they exerted their influence at a “local” or “regional” scale. All models accounted for spatio‐temporal differences in sampling protocols and individual reproductive strategy. We estimated and interpreted coefficients using Bayesian theory.

Our findings supported our predictions. Juvenile salmon were longer in years of higher overwinter water temperature and this effect was best parameterised as a single “regional” coefficient applicable to all three rivers. Similarly, spring mean temperature was best parameterised with a single “regional” nonlinear coefficient. In contrast, juvenile salmon were shorter in years of high densities of competing conspecifics and their interaction with total mean discharge and these effects were represented by “local” river‐specific coefficients. Summer droughts had a negative effect on juvenile salmon length but was best parameterised as a single “regional” coefficient, contrary to our expectations.

We show that environmental variables affect biological processes at different but predictable geographical scales. Temperature‐related variables affect body sizes of exothermic animals at a regional scale, whereas non‐temperature variables, such as the density of conspecific competitors and water abstraction, exert their influence at a local scale. These findings highlight the importance of integrating local and regional management plans to mitigate the impacts of climate change on the body size, and ultimately the conservation, of exothermic species.
Heat‐wave effects on greenhouse gas emissions from shallow lake mesocosms
Authors: Audet Joachim , Neif Érika M. , Cao Yu , Hoffmann Carl C. , Lauridsen Torben L. , Larsen Søren E. , Søndergaard Martin , Jeppesen Erik , Davidson Thomas A.
Published: April 2017

Shallow lakes are a key component of the global carbon cycle. It is, therefore, important to know how shallow lake ecosystems will respond to the current climate change. Global warming affects not only average temperatures, but also the frequency of heat waves (HW). The impact of extreme events on ecosystems processes, particularly greenhouse gas (GHG) emissions, is uncertain.

Using the world's longest‐running shallow lake experiment, we studied the effects of a simulated summer HW on the fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). The experimental mesocosms had been exposed to different temperature treatments and nutrient loading for 11 years prior to the artificial HW.

In general, there was an increase in total GHG emissions during the 1‐month artificial HW, with a significant increase in CO2, CH4 and N2O being observed in the shallow lake mesocosms. No significant effect of the HW on CO2 emissions could be traced, though, in the mesocosms with high nutrient levels. Furthermore, the data suggested that in addition to the direct effect of increased temperature on metabolic processes during the HW, biotic interactions exerted a significant control of GHG emissions. For example, at low nutrient levels, increased CO2 emissions were associated with low macrophyte abundance, whereas at high nutrient levels, decreased phytoplankton abundance was linked to increased emissions of CO2 and CH4.

In contrast to the observable heat‐wave effect, no clear general effect of the long‐term temperature treatments could be discerned over the summer, likely because the potential effects of the moderate temperature increase, applied as a press disturbance, were overridden by biotic interactions. This study demonstrates that the role of biotic interactions needs to be considered within the context of global warming on ecosystem processes.
Shifting microbial communities sustain multiyear iron reduction and methanogenesis in ferruginous sediment incubations
Authors: Bray M. S. , Wu J. , Reed B. C. , Kretz C. B. , Belli K. M. , Simister R. L. , Henny C. , Stewart F. J. , DiChristina T. J. , Brandes J. A. , Fowle D. A. , Crowe S. A. , Glass J. B.
Published: April 2017

Reactive Fe(III) minerals can influence methane (CH4) emissions by inhibiting microbial methanogenesis or by stimulating anaerobic CH4 oxidation. The balance between Fe(III) reduction, methanogenesis, and CH4 oxidation in ferruginous Archean and Paleoproterozoic oceans would have controlled CH4 fluxes to the atmosphere, thereby regulating the capacity for CH4 to warm the early Earth under the Faint Young Sun. We studied CH4 and Fe cycling in anoxic incubations of ferruginous sediment from the ancient ocean analogue Lake Matano, Indonesia, over three successive transfers (500 days in total). Iron reduction, methanogenesis, CH4 oxidation, and microbial taxonomy were monitored in treatments amended with ferrihydrite or goethite. After three dilutions, Fe(III) reduction persisted only in bottles with ferrihydrite. Enhanced CH4 production was observed in the presence of goethite, highlighting the potential for reactive Fe(III) oxides to inhibit methanogenesis. Supplementing the media with hydrogen, nickel and selenium did not stimulate methanogenesis. There was limited evidence for Fe(III)‐dependent CH4 oxidation, although some incubations displayed CH4‐stimulated Fe(III) reduction. 16S rRNA profiles continuously changed over the course of enrichment, with ultimate dominance of unclassified members of the order Desulfuromonadales in all treatments. Microbial diversity decreased markedly over the course of incubation, with subtle differences between ferrihydrite and goethite amendments. These results suggest that Fe(III) oxide mineralogy and availability of electron donors could have led to spatial separation of Fe(III)‐reducing and methanogenic microbial communities in ferruginous marine sediments, potentially explaining the persistence of CH4 as a greenhouse gas throughout the first half of Earth history.
Self‐reported prevalence, description and management of pain in adults with haemophilia: methods, demographics and results from the Pain, Functional Impairment, and Quality of life (P‐FiQ) study
Authors: Witkop M. , Neff A. , Buckner T. W. , Wang M. , Batt K. , Kessler C. M. , Quon D. , Boggio L. , Recht M. , Baumann K. , Gut R. Z. , Cooper D. L. , Kempton C. L.
Published: April 2017

Introduction

Haemophilia is characterized by frequent haemarthrosis, leading to acute/chronic joint pain.

Aim

To assess self‐reported prevalence, description and management of pain in adult males with mild‐to‐severe haemophilia and history of joint pain/bleeding.

Methods

Participants completed a pain survey and five patient‐reported outcome instruments assessing pain, functional impairment and health‐related quality of life (HRQoL).

Results

Of 381 participants enrolled, median age was 34 years; 77% had haemophilia A, 71% had severe disease and 65% were overweight/obese. Many (56%) were not receiving routine infusions; 30% never received routine infusions. During the prior 6 months, 20% experienced acute pain, 34% chronic pain and 32% both acute/chronic pain. Subjects with both acute/chronic pain (vs. none, acute or chronic) were more likely to be depressed (30% vs. 0–15%), obese (35% vs. 20–29%) and have lower HRQoL (mean EQ‐5D visual analog scale, 69 vs. 83–86) and function (median overall Hemophilia Activities List, 60 vs. 88–99). Most common analgesics used for acute/chronic pain during the prior 6 months were acetaminophen (62%/55%) and non‐steroidal anti‐inflammatory drugs (34%/49%); most common non‐pharmacologic strategies were ice (65%/33%) and rest (51%/33%). Hydrocodone‐acetaminophen was the most common opioid for both acute/chronic pain (30%); other long‐acting opioids were infrequently used specifically for chronic but not acute pain (morphine, 7%; methadone, 6%; fentanyl patch, 2%).

Conclusion

Patients with chronic pain, particularly those with both acute/chronic pain, frequently experience psychological issues, functional disability and reduced HRQoL. Treatment strategies for acute pain (e.g. routine infusions to prevent bleeding) and for chronic pain (e.g. long‐acting opioids) may be underused.
Dinosaur Tail Sign: A Useful Spinal MRI Finding Indicative of Cerebrospinal Fluid Leakage
Authors: Sakurai Keita , Kanoto Masafumi , Nakagawa Motoo , Shimohira Masashi , Tokumaru Aya M. , Kameyama Masashi , Shimoji Keigo , Morimoto Satoru , Matsukawa Noriyuki , Nishio Minoru , Shibamoto Yuta
Published: April 2017

Objective

To evaluate the imaging characteristics and diagnostic utility of the “Dinosaur tail sign” in the diagnosis of cerebrospinal fluid (CSF) leakage.

Background

The authors propose the “Dinosaur tail sign,” defined as a combination of the dorsal epidural hyperintensities, fat tissue, spinal cord, and cauda equine on lumbosacral sagittal fat‐suppressed T2‐weighted image (FST2WI), as a sensitive indicator for diagnosing CSF leakage.

Methods

Imaging characteristics of the “Dinosaur tail sign” was evaluated in seven spontaneous intracranial hypotension (SIH) and 23 iatrogenic CSF leakage (ICSFL) patients. Additionally, the diagnostic index was compared between the “Dinosaur tail sign” and other previously reported useful magnetic resonance imaging (MRI) and magnetic resonance myelography (MRM) findings.

Results

In contrast to other imaging findings including the epidural expansion, floating dural sac sign, and distension of the spinal epidural veins on MRI, and paraspinal fluid collections (PFC) on MRM, the “Dinosaur tail sign” was found equally in both SIH and ICSFL patients (6 SIH and 19 ICSFL; 83% of all patients with CSF leakage). The “Dinosaur tail sign” showed sufficient diagnostic utility (sensitivity 83%, specificity 94%, accuracy 89%) that was comparable to that of PFC.

Conclusion

The “Dinosaur tail sign” is a useful imaging finding suggestive of CSF leakage. Evaluation of subtle interspinous arched hyperintensities on spinal MRI is mandatory for the diagnosis of SIH and ICSFL.
Quantifying the importance of multi‐scale management and environmental variables on moorland bird abundance
Authors: Buchanan Graeme M. , Pearce‐Higgins James W. , Douglas David J.T. , Grant Murray C.
Published: April 2017

UK moorlands are semi‐natural habitats managed for a mix of livestock, game shooting and forestry, among other activities. An assessment of the importance of characteristics that correlate with moorland bird populations of high conservation importance can inform appropriate management at appropriate locations. We use hierarchical partitioning to assess the absolute and relative importance of climate, topography, soil, landscape management (wider scale habitat configuration of forestry and agriculture) and site‐based management (indices of predator control, and vegetation characteristics) in determining the abundance of a suite of upland birds in four regions of the UK. Unmeasured region‐specific effects often made the largest contribution to models. Physical characteristics (climate, topography, soil) were important and on average explained a similar amount of variation to site‐based management. However, there was considerable interspecific variation in the importance of both. Landscape‐scale variables were generally of low importance. An index of predator control was positively correlated with the abundance of Red Grouse Lagopus lagopus scotica and two waders. Vegetation characteristics (composition and structure) were, together, strong correlates of the abundance of passerine species. Vegetation characteristics were as important as indices of predator control for waders and grouse. The importance of regional effects, physical characteristics and variables relating to management suggest targeting site‐based management (such as predator control or vegetation management) to the areas where physical characteristics are most favourable. The most beneficial management will vary between species, necessitating a mosaic of management options across upland areas to benefit all species.
Expression and trafficking of MR1
Authors: Lamichhane Rajesh , Ussher James E.
Published: April 2017

MHC class I‐related gene protein (MR1) is a non‐polymorphic MHC class IB antigen‐presenting molecule that is the restricting molecule for mucosal‐associated invariant T (MAIT) cells, a prominent population of innate‐like antibacterial T cells. The MAIT cell–MR1 axis represents a new paradigm in antigen presentation, with the MR1 ligand derived from vitamin B compounds or their metabolic precursors. Many bacteria and some fungi produce the activating ligand for MR1. In evolution, MR1 is highly conserved in most, but not all, mammals. In humans and rodents it is expressed in a broad range of cell types, both haematopoietic and non‐haematopoietic, although cell surface expression has been difficult to detect. Although MR1 trafficking shares features with both the MHC class I and MHC class II pathways, it is distinct. Several strands of evidence suggest that the intracellular location where MR1 is loaded differs for soluble ligand and for ligand derived from intact bacteria. The regulation of MR1 surface expression may also vary between different cell types. This paper will review what is currently known about the expression and trafficking of MR1 and propose a model for the loading and trafficking of MR1.
Activation of the Akt–CREB signalling axis by a proline‐rich heptapeptide confers resistance to stress‐induced cell death and inflammation
Authors: Herkel Johannes , Schrader Jörg , Erez Neta , Lohse Ansgar W. , Cohen Irun R.
Published: April 2017

Cell stress of various kinds can lead to the induction of cell death and a damaging inflammatory response. Hence, a goal of therapeutic cell‐stress management is to develop agents that might effectively regulate undesirable cell death and inflammation. To that end, we developed a synthetic peptide of seven amino acids based on structural mimicry to a functional domain of p53, a key factor in the responses of cells to stressful stimuli. This heptapeptide, which we term Stressin‐1, was found to inhibit both cell death and the secretion of inflammatory mediators by various cell types in response to different stressful agents in vitro. The combined anti‐inflammatory and anti‐apoptotic activities of Stressin‐1 were associated with a cellular signalling cascade that induced activation of Akt kinase and activation of the cAMP response element‐binding protein (CREB) transcription factor. These immediate signalling events led to the inhibition of the signal transducer and activator of transcription and nuclear factor‐κB pathways 24 hr later. Unexpectedly, we found no evidence for a direct involvement of p53 in the effects produced by Stressin‐1. Intraperitoneal administration of 100 μg of Stressin‐1 to lethally irradiated mice significantly protected them from death. These findings show that activating the Akt–CREB axis with Stressin‐1 can counteract some of the undesirable effects of various cell stresses. Stressin‐1 may have clinical usefulness.
Inversion domain boundaries in Mn and Al dual‐doped ZnO: Atomic structure and electronic properties
Authors: Hoemke Joshua , Tochigi Eita , Tohei Tetsuya , Yoshida Hidehiro , Shibata Naoya , Ikuhara Yuichi , Sakka Yoshio
Published: April 2017

The atomic and electronic structures of inversion domain boundaries in Mn‐Al dual‐doped ZnO (Zn0.89Mn0.1Al0.01O) have been investigated. Using atomic‐resolution scanning transmission electron microscopy, a head‐to‐head c‐axis configuration and cation stacking sequence of αβαβ|γ|αβαβ along the c‐axis were observed at the basal‐plane inversion domain boundary. Energy‐dispersive X‐ray spectroscopy and electron energy‐loss spectroscopy revealed significant localization of Mn and minor localization of Al at the basal‐plane inversion domain boundary. Based on experimental findings, a Mn‐doped basal‐plane inversion domain boundary slab model was constructed and refined by first principles calculations. The model is in agreement with atomic‐resolution images. The local electronic density of states of the slab model basal‐plane inversion domain boundary shows a hybridization of the Mn d and O p states within the valence band and localized Mn d states in the conduction band. The thermoelectric properties of Zn0.99−xMnxAl0.01O ceramics have been reported in a previous work. In this work, the effects of inversion domain boundaries on the thermoelectric properties are discussed. In comparison to Zn0.99−xMnxAl0.01O ceramics with x≤0.05, inversion domain boundaries in Zn0.89Mn0.1Al0.01O caused thermal and electrical conductivity reduction due to interface scattering of phonons and electrons. The Seebeck coefficient increased, suggesting electron filtering at inversion domain boundaries.
Diurnal body temperature patterns in free‐ranging populations of two southern African arid‐zone nightjars
Authors: O'Connor Ryan S. , Brigham R. Mark , McKechnie Andrew E.
Published: April 2017

Endotherms allocate large amounts of energy and water to the regulation of a precise body temperature (Tb), but can potentially reduce thermoregulatory costs by allowing Tb to deviate from normothermic levels. Many data on heterothermy at low air temperatures (Ta) exist for caprimulgids, whereas data on thermoregulation at high Ta are largely absent, despite members of this taxon frequently roosting and nesting in sites exposed to high operative temperatures. We investigated thermoregulation in free‐ranging rufous‐cheeked nightjars Caprimulgus rufigena and freckled nightjars Caprimulgus tristigma in the southern African arid zone. Individuals of both species showed labile Tb fluctuating around a single modal Tb (Tb‐mod). Average Tb‐mod was 39.7°C for rufous‐cheeked nightjars and 39.0°C for freckled nightjars. In both species, diurnal Tb increased with increasing Ta. At Ta ≥ 38°C, rufous‐cheeked nightjar mean Tb increased to 42°C, equivalent to 2.3°C above Tb‐mod. Under similar conditions, freckled nightjar Tb was on average only 1.1°C above Tb‐mod, with a mean Tb of 40.0°C. Freckled nightjars are one of the most heterothermic caprimulgids investigated to date, but our data suggest that during hot conditions this species maintains Tb within a narrow range above Tb‐mod, possibly reflecting an evolutionary tradeoff between decreased thermal sensitivity to lower Tb but increased sensitivity to high Tb. These findings reveal how general thermoregulatory patterns at similar Ta can vary even among closely related species.
Does tree growth sensitivity to warming trends vary according to treeline form?
Authors: Treml Václav , Veblen Thomas T.
Published: April 2017

Aim

Whereas many treelines are advancing coincident with climate warming, many other treelines are stationary. Differential sensitivity to warming trends may be partially accounted for by differences in the climatic limits associated with distinct treeline forms such as diffuse, abrupt and krummholz treelines. We tested the hypothesis that only diffuse treelines are strictly growth‐limited by low temperatures and thus should benefit from warming more than abrupt or krummholz treelines.

Location

Colorado Front Range, USA

Methods

The growth‐climate responses of trees growing at different treeline forms were examined. We built tree‐ring chronologies from seven sites covering diffuse, abrupt and krummholz treelines for two conifer species – Abies lasiocarpa and Picea engelmannii. These chronologies were correlated with climatic variables and compared in terms of growth trends.

Results

The variance in tree‐ring width chronologies was primarily attributed to tree species and secondarily to treeline form. Tree growth at krummholz sites was limited by the length of the growing season, and ring widths of trees at abrupt treelines also showed a strong drought signal. The growth‐climate response of diffuse treelines varied by sites and trees, showing mostly a mixed climatic signal. In general, trees limited by the length of the growing season or by the growing season temperatures were characterized by the increasing growth rates during the last three decades, whereas trees limited by other factors displayed ambiguous growth trends.

Main conclusions

Recent growth increase was most pronounced for Picea engelmannii at the krummholz treeline form. As a refinement of the treeline form framework, we suggest that temperature‐limited tree growth at krummholz treelines may be important, whereas the main common feature of diffuse treelines is their population dynamics and not temperature‐limited radial growth. Our results highlight the importance of considering differences in species and treeline form in projecting future treeline advances under a warming climate.
Global variation in woodpecker species richness shaped by tree availability
Authors: Ilsøe Sigrid Kistrup , Kissling W. Daniel , Fjeldså Jon , Sandel Brody , Svenning Jens‐Christian
Published: April 2017

Aim

Species richness patterns are generally thought to be determined by abiotic variables at broad spatial scales, with biotic factors being only important at fine spatial scales. However, many organism groups depend intimately on other organisms, raising questions about this generalization. As an example, woodpeckers (Picidae) are closely associated with trees and woody habitats because of multiple morphological and ecological specializations. In this study, we test whether this strong biotic association causes woodpecker diversity to be closely linked to tree availability at a global scale.

Location

Global.

Methods

We used spatial and non‐spatial regressions to test for relationships between broad‐scale woodpecker species richness and predictor variables describing current and deep‐time availability of trees, current climate, Quaternary climate change, human impact, topographical heterogeneity and biogeographical region. We further used structural equation models to test for direct and indirect effects of predictor variables.

Results

There was a strong positive relationship between woodpecker species richness and current tree cover and annual precipitation, respectively. Precipitation also showed a strong indirect effect on woodpecker richness via the effects on tree availability. Deep‐time tree availability, Quaternary climate change, human influence and other abiotic factors showed weaker direct effects. Human influence had a negative effect on tree availability, and hence a negative indirect effect on woodpecker species richness.

Main conclusions

Global species richness of woodpeckers is primarily shaped by current tree cover and precipitation, reflecting a strong biotic association between woodpeckers and trees. Human influence can have a negative effect on woodpecker diversity when humans reduce tree availability. Hence, woodpeckers exemplify how broad‐scale diversity patterns are predominantly shaped by a biotic factor, and how climate and human influence can have indirect effects on animal biodiversity via the effects on tree availability and forest cover.
The southern coastal Beringian land bridge: cryptic refugium or pseudorefugium for woody plants during the Last Glacial Maximum?
Authors: Wang Yue , Heintzman Peter D. , Newsom Lee , Bigelow Nancy H. , Wooller Matthew J. , Shapiro Beth , Williams John W.
Published: April 2017

Aim

The Bering Land Bridge (BLB) connected Asia and North America during glacial periods, supported a diverse ecosystem of now‐vanished megafauna, and is a proposed glacial refugium. This study tests whether southern coastal Beringia was a refugium for woody taxa during the Last Glacial Maximum (LGM) and hypotheses about habitats available on the BLB before and after megafaunal extinction.

Location

St. Paul Island, Alaska.

Methods

We analysed sediment cores from the Lake Hill, with a new age model anchored by 18 radiocarbon dates and multiple palaeoecological indicators (sedimentary ancient DNA [sedaDNA], macrobotanical fossils, and pollen) for the presence/absence of four woody genera: Picea, Betula, Alnus and Salix. We reconstructed vegetation history and compare St. Paul tundra composition to mainland counterparts.

Results

St. Paul has been continuously occupied by graminoid‐forb tundra with prostrate shrubs (Salix, Ericaceae) since 18,000 years before present (yr bp). Fossil pollen of Picea, Pinus, Betula and Alnus is present in the Lake Hill sediments at low relative abundances and accumulation rates, consistent with long‐distance transport. Macrobotanical fossils and sedaDNA analyses do not support Picea, Betula and Alnus presence. The St. Paul modern and fossil pollen assemblages are compositionally unlike mainland counterparts, but most closely resemble Arctic herbaceous tundra. Stratigraphically constrained cluster analysis indicates no major change in the vegetation after woolly mammoth extinction at 5600 yr bp, although Poaceae, Cyperaceae, Equisetum and forb abundances increase.

Main conclusions

This study strongly indicates that St. Paul and, by implication, southern coastal Beringia were not refugia for woody taxa during the LGM. The persistence of prostrate shrub‐graminoid tundra supports interpretations that herbaceous tundra prevailed on southern Beringia during the LGM, whilst not ruling out the possibility of mesic shrub tundra in the interior. This herbaceous tundra supported an island refugium for woolly mammoth for 8000 years, showing no major vegetation composition changes after extinction.
Periodontitis changes renal structures by oxidative stress and lipid peroxidation
Authors: França Luiz Felipe C. , Vasconcelos Any Carolina C. G. , da Silva Felipe R. P. , Alves Even H. P. , Carvalho Joaquina S. , Lenardo David D. , de Souza Luan K. M. , Barbosa André L. R. , Medeiros Jand‐Venes R. , de Oliveira Jefferson S. , Vasconcelos Daniel F. P.
Published: April 2017

Objective

The aim of this study was to investigate whether experimental periodontitis cause changes to the renal tissues and imbalance in oxidative stress in kidneys.

Methods

Twenty‐two female Wistar rats were separated into two groups: control and periodontitis. We assessed the following parameters: gingival bleeding index (GBI), tooth mobility, gum malondialdehyde (MDA), myeloperoxidase (MPO) activity, probing pocket depth (PPD), alveolar bone loss (ABL) for periodontal tissues; histomorphometric measures associated with renal corpuscle and histopathological aspects (evaluation of brush border) for kidneys; as also blood and urine biomarkers. Finally, we evaluated renal oxidative stress through glutathione (GSH) and MDA respectively.

Results

With regard to renal histomorphometry, significant differences were observed in all parameters assessed. In relation periodic acid Schiff (PAS) staining, disruption was observed of brush border in the periodontitis group in the renal tubules in comparison with the control group. The periodontitis group presented significantly higher MDA and lower GSH concentrations in the kidneys compared with animals without periodontitis.

Conclusion

The induced periodontitis caused histomorphometric changes in renal tissues as well as disruption of the brush border in renal tubules, alterations associated with increase in oxidative stress in kidneys. However, these alterations were not sufficient to cause differences in the renal function markers.
Predictors of long‐term outcomes in patients undergoing periodontal maintenance
Authors: Martinez‐Canut Pedro , Llobell Andrés , Romero Antonio
Published: April 2017

Aim

This retrospective study aimed to characterize the baseline status of patients following periodontal maintenance, analysing the association between the long‐term outcome of these patients, smoking, bruxism, and the main clinical and radiographic variables.

Material and methods

A sample of 174 patients with moderate to severe periodontitis was refined into homogeneous subsamples according to smoking and bruxism and the rate of tooth loss due to periodontal disease (TLPD): 0, 1–2, and >2 teeth. The association and the distribution (χ² test) of the variables within the subsamples were analysed.

Results

Smoking and bruxism were significantly associated with higher TLPD rates. Vertical and circumferential bone defects (p < .0001), and abfractions (p < .0001) were associated with bruxism and particularly with bruxism and TLPD >2.

Furcation defects (p = .0002), fewer radio‐opaque subgingival calculus (χ² p < .0001), a lower mean Gingival index (χ² p = .027), and increased mean recessions >1.5 mm (χ² p = .0026) were associated with smoking and higher TLPD rates. The mean baseline mobility, abfractions, and recessions characterized two basic types of TLPD.

Conclusions

Smoking, bruxism, and routine clinical and radiological parameters can be used to characterize the baseline status of patients with worse outcomes.
Rheological properties of a polysaccharide with highly sulfated groups extracted from Gracialaria greville
Authors: Huang Qun , Zhang Huoping , Song Hongbo , Wang Yiwei , An Fengping
Published: April 2017

In the present study, rheological characteristics of a polysaccharide with highly sulfated groups extracted from Gracilaria greville (Gracilaria greville sulfated polysaccharide, GSPS) were investigated by steady shear and dynamic viscoelastic assays. To well understand the associations of rheological characteristics with GSPS structure, the rheological characteristics of agar were also assessed as a reference. Compared with agar, GSPS had lower viscosity, thixotropy, melting point temperature (GSPS 37 °C, agar 91 °C) and gelling point temperature (GSPS 10 °C, agar 37 °C) than agar. This might be related to the lower 3,6‐anhydro‐galactose content, but much more sulfated groups in GSPS. These results showed that GSPS could be used as a thickener in refrigerated food processing. Furthermore, the fluid type of GSPS was not altered with changes of GSPS concentration, pH value, and metal ion and sucrose concentrations; however, the viscosity of the solution system significantly decreased while thixotropy increased with pH of the GSPS solution adjusted to 3.0 from 6.0. The same results were obtained with increasing of NaCl, CaCl2, and sucrose concentrations. These findings provide a guidance for GSPS application in food processing.

Practical applications

Gracilaria greville is commonly known as one of the most economical marine red alga in China, and the polysaccharides extracted from G. greville are compounds simply of agar and SPS. In this manuscript, for the first time the rheological property of polysaccharide, with high sulfated groups extracted from Gracilaria greville, was reported by steady shear and dynamic viscoelastic test. To better understand the connection between rheological characteristics and construction of GSPS, the agar sold in market was also investigated. The finding will be help to fully understand the comprehensively investigated, including the difference with agar (sold in market) under different temperature and the flow behavior of GSPS under different condition.
Comparison of multifactor scoring systems and single serum markers for the early prediction of the severity of acute pancreatitis
Authors: He Wen‐Hua , Zhu Yin , Zhu Yong , Jin Qi , Xu Hong‐Rong , Xion Zhi‐Juan , Yu Min , Xia Liang , Liu Pi , Lu Nong‐Hua
Published: April 2017

Background

The purpose of this study was to clarify whether the current scoring systems and single serum markers used in pancreatitis remain applicable for the early prediction of infected pancreatic necrosis (IPN) and the severity and mortality of acute pancreatitis (AP) in accordance with the revised Atlanta and determinant‐based classifications.

Methods

Demographic, clinical, and laboratory data from 708 consecutive patients with AP were prospectively collected between January 2011 and December 2012. The severity was classified using the revised Atlanta and determinant‐based classification systems. The predictive accuracies for moderately severe AP (MSAP), severe AP (SAP), critically severe AP (CAP), IPN, and mortality were measured using area under the receiver operating characteristic curves.

Results

The receiver operating characteristic analysis showed that the multifactor scoring systems and single serum markers had a low predictive accuracy regarding moderately severe AP. The Acute Physiology and Chronic Health Evaluation (APACHE) II score had the highest accuracy in predicting SAP with area under the curve (AUC) values of 0.75 (95% CI = 0.71–0.79) and 0.77 (95% CI = 0.73–0.81) at 24 and 48 h after admission, respectively. Procalcitonin was the most accurate predictor for CAP and IPN, with respective AUCs of 0.86 (95% CI = 0.82–0.89) and 0.83 (95% CI = 0.78–0.87) at 48 h after admission. In predicting mortality, both the APACHE II score and blood urea nitrogen had the highest accuracy.

Conclusions

The APACHE II score had the highest predictive accuracy for SAP and mortality as defined by the revised Atlanta classification, whereas procalcitonin was the most accurate predictor for CAP and IPN.
Post‐lunch triglyceridaemia associates with HDLc and insulin resistance in fasting normotriglyceridaemic menopausal women
Authors: Sanz‐Paris A. , Rodriguez‐Valle A. , Navarro M. A. , Puzo‐Foncillas J. , Arbones‐Mainar J. M.
Published: April 2017

Objectives

Post‐prandial hypertriglyceridaemia (P‐HTG) is associated with cardiovascular disease. This association is of paramount importance during menopause, which is also related to reduced high‐density lipoprotein‐cholesterol (HDLc) and elevated triglyceride (TG) levels. We aimed to provide a self‐assesing tool to screen for P‐HTG in menopausal women who were normotriglyceridaemic at fasting and adhered to a Mediterranean‐style eating pattern.

Methods

We performed oral fat loading tests (OFLT) in combination with self‐measurements of diurnal capillary TG at fixed time‐points (DC‐TG) in 29 healthy menopausal women. TG levels >220 mg dL−1 at any given time during the OFLT served as diagnostic criteria for P‐HTG. Subsequently, DC‐TG profiles were examined to determine the best mealtime (breakfast, lunch or dinner), as well as optimal cut‐off points to classify these women as having P‐HTG according to the OFLT. Insulin resistance was defined as the upper tertile of the homeostatic model assessment of insulin resistance.

Results

We found that, despite having normal fasting TG levels, P‐HTG was highly prevalent (approximately 40%). Moreover, self‐assessed 3‐h post‐lunch TG levels >165 mg dL−1 increased the odds of having hypo‐HDL cholesterolaemia by 14.1‐fold (P = 0.026) and the odds of having insulin resistance by 31.6‐fold (P = 0.007), adjusted for total fat intake in women adhering to a Mediterranean eating pattern having their highest energy intake at lunch.

Conclusions

Self‐assessed 3‐h post‐lunch TG can be used to study post‐prandial TG metabolism in Southern European menopausal women who are normotriglyceridaemic at fasting. Characterising an individual's post‐prandial response may help menopausal women to evaluate their risk of cardiovascular disease.
Pilot survey of the health of Massachusetts dentists
Authors: Nalliah Romesh P. , Budd Alan , Allareddy Veerasathpurush
Published: April 2017

Aim

Dentistry is a career that is very rewarding because of the direct opportunity to deliver essential health services to patients in need. Dentistry is also very demanding; mentally, physically, and even emotionally. Little is known about the health of dentists and how it compares to the health of the general population. The aim of the present study was to report on the general health and health practices of dentists in Massachusetts.

Methods

A medical health and health practices survey was developed from the Delaware Valley Community Health Center and customized. The surveys contained 36 questions relating to demographics, general health, and health practices.

Results

A total of 399 dentists completed the survey. Of those who responded to the survey, 78.2% were males, 32.6% were 56‐65 years of age, 23.1% were 66‐75 years of age, and 21.6% were 46‐55 years of age.

Conclusion

This pilot study highlights several health issues where dentists seem to have a lower incidence than the general population: asthma, depression, diabetes, hearing loss, obesity, smoking, sleep apnea, and thyroid disease. However, there are some health issues where dentists have a higher incidence than the general population: taking at least one prescription medication, gastroesophageal reflux disease, some form of cancer, back pain, neck pain, headache, osteoarthritis, rheumatic arthritis, psoriatic arthritis, and alcohol abuse.
Interpreting granulite facies events through rare earth element partitioning arrays
Authors: Taylor R. J. M. , Clark C. , Harley S. L. , Kylander‐Clark A. R. C. , Hacker B. R. , Kinny P. D.
Published: April 2017

The use of rare earth element (REE) partition coefficients is an increasingly common tool in metamorphic studies, linking the growth or modification of accessory mineral geochronometers to the bulk silicate mineral assemblage. The most commonly used mineral pair for the study of high‐grade metamorphic rocks is zircon and garnet. The link from U–Pb ages provided by zircon to the P–T information recorded by garnet can be interpreted in relation to experimental data. The simplistic approach of taking the average REE abundances for zircon and garnet and comparing them directly to experimentally derived partition coefficients is imperfect, in that it cannot represent the complexity of a natural rock system. This study describes a method that uses all the zircon analyses from a sample, and compares them to different garnet compositions in the same rock. Using the most important REE values, it is possible to define zircon–garnet equilibrium using an array rather than an average. The array plot describes partitioning between zircon and garnet using DYb and DYb/DGd as the defining features of the relationship. This approach provides far more sensitivity to mineral reactions and diffusional processes, enabling a more detailed interpretation of metamorphic history of the sample.
The Impact of CT Perfusion Threshold on Predicted Viable and Nonviable Tissue Volumes in Acute Ischemic Stroke
Authors: Huang Xuya , Kalladka Dheeraj , Cheripelli Bharath Kumar , Moreton Fiona Catherine , Muir Keith W.
Published: April 2017

BACKGROUND AND PURPOSE

Perfusion imaging is used for patient selection in clinical practice and trials. Postprocessing and definitions of tissue viability are nevertheless not standardized. We compared the lesion volumes generated with two well‐recognized perfusion tissue definitions in a single‐center phase 2 thrombolysis study.

METHODS

We analyzed perfusion imaging data from the Alteplase‐Tenecteplase Trial Evaluation for Stroke Thrombolysis (ATTEST) study using two popular tissue viability thresholds (ischemic core definition: (1) cerebral blood volume < 2.0 mL/100 g−1 or (2) relative cerebral blood flow < 40% that of the contralesional hemisphere and relative delay time >2 seconds; penumbra definitions: (1) mean transit time > 145% of contralesional hemisphere or (2) relative delay time < 2 seconds). We compared volumes of core and penumbra, mismatch ratio, percentage, and volume of penumbra salvaged at 24 hours.

RESULTS

We included 73 (tenecteplase = 36, alteplase = 37) patients who had analyzable perfusion lesions at baseline. Significant differences were found in core volumes using the two thresholds (33 ± 37 mL vs. 26 ± 32 mL, P < .001), as was mismatch ratio (2.5 ± .9 vs. 4.2 ± 3.7, P < 0.001). The volume of penumbra salvaged at 24 hours (30 ± 19 mL vs. 35 ± 26 mL, P = .043) differed significantly, although the percentages of penumbra salvaged did not (P = .2). No difference was found between the two thrombolytic agents in the percentages of penumbra salvaged using either threshold.

CONCLUSION

Two commonly used tissue definitions generated significantly different lesion volumes and mismatch ratios. Threshold selection may have significant impact on patient selection for trials or reperfusion therapies.
Impact of viral hepatitis aetiology on survival outcomes in hepatocellular carcinoma: A large multicentre cohort study
Authors: Mgaieth S. , Kemp W. , Gow P. , Fink M. , Lubel J. , Nicoll A. , Gazzola A. , Hong T. , Ryan M. , Knight V. , Dev A. T. , Sood S. , Bell S. , Paul E. , Roberts S. K.
Published: April 2017

While HBV and HCV are risk factors for HCC, uncertainty exists as to whether these viral infections have prognostic significance in HCC. Thus, we compared the overall survival of patients with HBV, HCV and nonviral HCC, and evaluated whether the presence of HBV and HCV predicts patient outcomes. We conducted a multicentre study of HCC cases diagnosed at six Melbourne tertiary hospitals between Jan 2000‐Dec 2014. Patient demographics, liver disease and tumour characteristics and patient outcomes were obtained from hospital databases, computer records and the Victorian Death Registry. Survival outcomes were compared between HBV, HCV and nonviral hepatitis cases and predictors of survival determined using Cox proportional hazards regression. There were 1436 new HCC cases identified including 776 due to viral hepatitis (HBV 235, HCV 511, HBV‐HCV 30) and 660 from nonviral causes. The median survival of HBV, HCV and nonviral HCC patients was 59.1, 28.4 and 20.9 months, respectively (P<.0001). On multivariate analysis, independent risk factors for survival included HCC aetiology, gender, BCLC stage, serum AFP, total number and size of lesions, and serum creatinine and albumin. After adjusting for these and method of detection, HBV remained an independent predictor of improved overall survival when compared to both nonviral (HR 0.60%, 95% CI 0.35‐0.98; P=.03) and HCV‐related HCC (HR 0.51%, 95% CI 0.30‐0.85; P=.01). In this large multicentre study, HBV is independently associated with improved overall survival compared with HCV and nonviral‐related HCC. Further studies are needed to determine the underlying factor(s) responsible.
A numerical assessment of simple airblast models of impact airbursts
Authors: Collins Gareth S. , Lynch Elliot , McAdam Ronan , Davison Thomas M.
Published: April 2017

Asteroids and comets 10–100 m in size that collide with Earth disrupt dramatically in the atmosphere with an explosive transfer of energy, caused by extreme air drag. Such airbursts produce a strong blastwave that radiates from the meteoroid's trajectory and can cause damage on the surface. An established technique for predicting airburst blastwave damage is to treat the airburst as a static source of energy and to extrapolate empirical results of nuclear explosion tests using an energy‐based scaling approach. Here we compare this approach to two more complex models using the iSALE shock physics code. We consider a moving‐source airburst model where the meteoroid's energy is partitioned as two‐thirds internal energy and one‐third kinetic energy at the burst altitude, and a model in which energy is deposited into the atmosphere along the meteoroid's trajectory based on the pancake model of meteoroid disruption. To justify use of the pancake model, we show that it provides a good fit to the inferred energy release of the 2013 Chelyabinsk fireball. Predicted overpressures from all three models are broadly consistent at radial distances from ground zero that exceed three times the burst height. At smaller radial distances, the moving‐source model predicts overpressures two times greater than the static‐source model, whereas the cylindrical line‐source model based on the pancake model predicts overpressures two times lower than the static‐source model. Given other uncertainties associated with airblast damage predictions, the static‐source approach provides an adequate approximation of the azimuthally averaged airblast for probabilistic hazard assessment.
Mycobacterium tuberculosis proteasomal ATPase Mpa has a β‐grasp domain that hinders docking with the proteasome core protease
Authors: Wu Yujie , Hu Kuan , Li Defeng , Bai Lin , Yang Shaoqing , Jastrab Jordan B. , Xiao Shuhao , Hu Yonglin , Zhang Susan , Darwin K. Heran , Wang Tao , Li Huilin
Published: April 2017

Mycobacterium tuberculosis (Mtb) has a proteasome system that is essential for its ability to cause lethal infections in mice. A key component of the system is the proteasomal adenosine triphosphatase (ATPase) Mpa, which captures, unfolds, and translocates protein substrates into the Mtb proteasome core particle for degradation. Here, we report the crystal structures of near full‐length hexameric Mtb Mpa in apo and ADP‐bound forms. Surprisingly, the structures revealed a ubiquitin‐like β‐grasp domain that precedes the proteasome‐activating carboxyl terminus. This domain, which was only found in bacterial proteasomal ATPases, buries the carboxyl terminus of each protomer in the central channel of the hexamer and hinders the interaction of Mpa with the proteasome core protease. Thus, our work reveals the structure of a bacterial proteasomal ATPase in the hexameric form, and the structure finally explains why Mpa is unable to stimulate robust protein degradation in vitro in the absence of other, yet‐to‐be‐identified co‐factors.