bluuebunny/crossref_metadata_2025 huggingface dataset:
Oral lorazepam can be substituted for intravenous midazolam when weaning paediatric intensive care patients off sedation
Authors: van der Vossen Anna C. , van Nuland Merel , Ista Erwin G. , de Wildt Saskia N. , Hanff Lidwien M.
Published: March 2018

Aim

Intravenous sedatives used in the paediatric intensive care unit (PICU) need to be tapered after prolonged use to prevent iatrogenic withdrawal syndrome (IWS). We evaluated the occurrence of IWS and the levels of sedation before and after conversion from intravenous midazolam to oral lorazepam.

Methods

This was a retrospective, observational, single cohort study of children under the age of 18 admitted to the PICU of the Erasmus MC‐Sophia Children's Hospital, Rotterdam, The Netherlands, between January 2013 and December 2014. The outcome parameters were the Sophia Observation withdrawal Symptoms (SOS) scale scores and COMFORT Behaviour scale scores before and after conversion.

Results

Of the 79 patients who were weaned, 32 and 39 had before and after SOS scores and 77 had COMFORT‐B scores. IWS was reported in 15 of 79 patients (19.0%) during the 48 hours before the start of lorazepam and 17 of 79 patients (21.5%) during the 48 hours after treatment started. Oversedation was seen in 16 of 79 patients (20.3%) during the 24 hours before substitution and in 30 of 79 patients (38.0%) during the 24 hours after substitution.

Conclusion

The weaning protocol was not able to prevent IWS in all patients, but converting from intravenous midazolam to oral lorazepam did not increase the incidence.
Initial series of magnetic resonance imaging (MRI)‐fusion targeted prostate biopsy using the first transperineal targeted platform available in the USA
Authors: Kosarek Christopher D. , Mahmoud Ali M. , Eyzaguirre Eduardo J. , Shan Yong , Walser Eric M. , Horn Gary L. , Williams Stephen B.
Published: March 2018

Objectives

To describe a step‐by‐step guide for using the first transperineal targeted prostate biopsy platform available in the USA.

Patients and Methods

A total of 32 men with elevated prostate‐specific antigen (PSA) levels were diagnosed with a region of interest on multiparametric magnetic resonance imaging (mpMRI) between February 2017 and January 2018. The transperineal targeted prostate biopsy procedure was accomplished via a transperineal approach and used a stepper, combined with advanced mpMRI/transrectal ultrasound fusion software, to perform targeted prostate biopsy. The detection of overall and clinically significant prostate cancer (PCa) was assessed as well as the rate of complications.

Results

The median patient age was 68.0 years and the median PSA was 8.0 ng/mL. Two patients (6%) were active surveillance candidates and 16 (50%) had a prior negative prostate biopsy. The detection rates for overall and clinically significant PCa were 81% and 59%, respectively. The two candidates for active surveillance and eight of the patients with a prior negative prostate biopsy had clinically significant PCa confirmed on targeted biopsy. There were no peri‐operative complications.

Conclusion

These results demonstrate the promising potential of the first transperineal targeted prostate biopsy platform in the USA as an alternative diagnostic method for PCa.
The fragility of statistically significant findings from randomised controlled trials in the urological literature
Authors: Narayan Vikram M. , Gandhi Shreyas , Chrouser Kristin , Evaniew Nathan , Dahm Philipp
Published: March 2018

Objectives

To use the Fragility Index to evaluate the robustness of statistically significant findings from urological randomised controlled trials (RCTs).

Materials and Methods

The ‘Fragility Index’ is defined as the minimum number of patients in one arm of a trial whose status would have to change from ‘event’ to ‘non‐event’, such that a statistically significant result becomes non‐significant. We identified all RCTs published in four major urology journals between 2011 and 2015, and we determined the Fragility Index values for those trials reporting statistically significant results of dichotomous outcomes using the Fisher's exact test.

Results

In all, 332 RCTs were identified, and 41 studies met the inclusion criteria. The median (interquartile range) Fragility Index was 3 (1, 4.5), indicating that an addition of only three alternate events to one arm of a typical trial would have eliminated its statistical significance. In 27/40 cases (67.5% of cases), the number of patients lost to follow‐up was larger than its Fragility Index.

Conclusions

The results of urology RCTs that study dichotomous outcomes and report statistically significant differences between groups are sometimes fragile and depend on few events. Urologists should interpret these RCTs cautiously, particularly when the number of participants lost to follow‐up exceeds the Fragility Index. Routine reporting of Fragility Index values alongside P values may provide additional guidance about the robustness of statistically significant findings.
Indicator value of oribatid mites in determining past permafrost dynamics in northern European sub‐Arctic peatlands
Authors: Markkula Inkeri , Oksanen Pirita , Kuhry Peter
Published: March 2018

Permafrost dynamics play an important role in the surface hydrology and carbon balance of northern peatlands. Plant macrofossil analysis with radiocarbon dating has been widely used in detecting past permafrost dynamics in peatlands; however, there is a lack of permafrost‐specific plant indicator species, which makes it challenging to determine the exact timing of historical permafrost aggradation. We investigated the indicator value of oribatid mites in determining past permafrost dynamics in sub‐Arctic peatlands. Analyses of subfossil oribatid mite assemblages of Holocene peat profiles from two mires, one in northern Finland and one in northeastern European Russia, were carried out and interpreted using modern calibration data from the same study areas. The results were compared with previously published reconstructions of permafrost history based on plant macrofossil analyses from the same locations. The results suggest that the oribatid mites Carabodes labyrinthicus, Chamobates borealis and Neoribates aurantiacus are promising indicator species to detect past permafrost occurrence in peatlands. In addition, N. aurantiacus is clearly associated with the presence of lichens, which is particularly useful because lichen remains are rarely preserved in peat deposits. Results are in accordance with earlier studies showing that oribatid mites are useful indicators of past environmental change.
The non‐biphenyl‐tetrazole angiotensin AT1 receptor antagonist eprosartan is a unique and robust inverse agonist of the active state of the AT1 receptor
Authors: Takezako Takanobu , Unal Hamiyet , Karnik Sadashiva S , Node Koichi
Published: March 2018

Background and Purpose

Conditions such as hypertension and renal allograft rejection are accompanied by chronic, agonist‐independent, signalling by angiotensin II AT1 receptors. The current treatment paradigm for these diseases entails the preferred use of inverse agonist AT1 receptor blockers (ARBs). However, variability in the inverse agonist activities of common biphenyl‐tetrazole ARBs for the active state of AT1 receptors often leads to treatment failure. Therefore, characterization of robust inverse agonist ARBs for the active state of AT1 receptors is necessary.

Experimental Approach

To identify the robust inverse agonist for active state of AT1 receptors and its molecular mechanism, we performed site‐directed mutagenesis, competition binding assay, inositol phosphate production assay and molecular modelling for both ground‐state wild‐type AT1 receptors and active‐state N111G mutant AT1 receptors.

Key Results

Although candesartan and telmisartan exhibited weaker inverse agonist activity for N111G‐ compared with WT‐AT1 receptors, only eprosartan exhibited robust inverse agonist activity for both N111G‐ and WT‐ AT1 receptors. Specific ligand–receptor contacts for candesartan and telmisartan are altered in the active‐state N111G‐ AT1 receptors compared with the ground‐state WT‐AT1 receptors, suggesting an explanation of their attenuated inverse agonist activity for the active state of AT1 receptors. In contrast, interactions between eprosartan and N111G‐AT1 receptors were not significantly altered, and the inverse agonist activity of eprosartan was robust.

Conclusions and Implications

Eprosartan may be a better therapeutic option than other ARBs. Comparative studies investigating eprosartan and other ARBs for the treatment of diseases caused by chronic, agonist‐independent, AT1 receptor activation are warranted.
Boosting phagocytosis and anti‐inflammatory phenotype in microglia mediates neuroprotection by PPARγ agonist MDG548 in Parkinson's disease models
Authors: Lecca Daniela , Janda Elzbieta , Mulas Giovanna , Diana Andrea , Martino Concetta , Angius Fabrizio , Spolitu Stefano , Casu Maria Antonietta , Simbula Gabriella , Boi Laura , Batetta Barbara , Spiga Saturnino , Carta Anna R
Published: March 2018

Background and Purpose

Microglial phenotype and phagocytic activity are deregulated in Parkinson's disease (PD). PPARγ agonists are neuroprotective in experimental PD, but their role in regulating microglial phenotype and phagocytosis has been poorly investigated. We addressed it by using the PPARγ agonist MDG548.

Experimental Approach

Murine microglial cell line MMGT12 was stimulated with LPS and/or MDG548, and their effect on phagocytosis of fluorescent microspheres or necrotic neurons was investigated by flow cytometry. Cytokines and markers of microglia phenotype, such as mannose receptor C type 1; MRC1), Ym1 and CD68 were measured by elisa and fluorescent immunohistochemistry. Levels of Beclin‐1, which plays a role in microglial phagocytosis, were measured by Western blotting. In the in vivo MPTP–probenecid (MPTPp) model of PD in mice, MDG548 was tested on motor impairment, nigral neurodegeneration, microglial activation and phenotype.

Key Results

In LPS‐stimulated microglia, MDG548 increased phagocytosis of both latex beads and necrotic cells, up‐regulated the expression of MRC1, CD68 and to a lesser extent IL‐10, while blocking the LPS‐induced increase of TNF‐α and iNOS. MDG548 also induced Beclin‐1. Chronic MPTPp treatment in mice down‐regulated MRC1 and TGF‐β and up‐regulated TNF‐α and IL‐1β immunoreactivity in activated CD11b‐positive microglia, causing the death of nigral dopaminergic neurons. MDG548 arrested MPTPp‐induced cell death, enhanced MRC1 and restored cytokine levels.

Conclusions and Implications

This study adds a novel mechanism for PPARγ‐mediated neuroprotection in PD and suggests that increasing phagocytic activity and anti‐inflammatory markers may represent an effective disease‐modifying approach.
Subtle changes in elevation shift bat‐assemblage structure in Central Amazonia
Authors: Capaverde Ubirajara Dutra , Pereira Lucas Gabriel do Amaral , Tavares Valéria da Cunha , Magnusson William E. , Baccaro Fabricio Beggiato , Bobrowiec Paulo Estefano D.
Published: March 2018

The distribution patterns of animal species at local scales have been explained by direct influences of vegetation structure, topography, food distribution, and availability. However, these variables can also interact and operate indirectly on the distribution of species. Here, we examined the direct and indirect effects of food availability (fruits and insects), vegetation clutter, and elevation in structuring phyllostomid bat assemblages in a continuous terra firme forest in Central Amazonia. Bats were captured in 49 plots over 25‐km² of continuous forest. We captured 1138 bats belonging to 52 species with 7056 net*hours of effort. Terrain elevation was the strongest predictor of species and guild compositions, and of bat abundance. However, changes in elevation were associated with changes in vegetation clutter, and availability of fruits and insects consumed by bats, which are likely to have had direct effects on bat assemblages. Frugivorous bat composition was more influenced by availability of food‐providing plants, while gleaning‐animalivore composition was more influenced by the structural complexity of the vegetation. Although probably not causal, terrain elevation may be a reliable predictor of bat‐assemblage structure at local scales in other regions. In situations where it is not possible to collect local variables, terrain elevation can substitute other variables, such as vegetation structure, and availability of fruits and insects.
Tim-3 exacerbates kidney ischaemia/reperfusion injury through the TLR-4/NF-κB signalling pathway and an NLR-C4 inflammasome activation
Authors: Guo Y , Zhang J , Lai X , Chen M , Guo Y
Published: March 2018

T cell immunoglobulin domain and mucin domain-containing molecule-3 (Tim-3), a member of the immunoglobulin superfamily, has been shown to play a crucial role in host adaptive immunity and tolerance. However, its role in kidney ischaemia–reperfusion injury (IRI) remains unknown. In this study, we investigated the role and mechanism of Tim-3 signalling after kidney IRI. In an established murine model of kidney IRI, we found that Tim-3 expression is enhanced on monocytes/macrophages. Anti-Tim-3 antibody RMT3-23 ameliorates biochemical and histological kidney injury, reduces apoptosis and decreases macrophage infiltration and cytokine production in ischaemic kidneys. Cell culture experiments also demonstrated that the role of Tim-3 in IRI-induced macrophage activation leads to the secretion of proinflammatory cytokines and chemokines. In addition, Toll-like receptor (TLR)-4 and Nod-like receptor (NLR) family CARD domain-containing protein 4 (NLR-C4) expression were enhanced after kidney IRI and decreased significantly by RMT3-23. Tim-3 not only promotes TLR-mediated nuclear factor kappa B (NF-κB) activation and cytokine and chemokine release, but also participates in NLR-C4 inflammasome activation. Taken together, our data confirm that Tim-3 signalling enhances injury after kidney IRI and demonstrated that Tim-3 is involved in regulating TLR-4/NF-κB signalling and NLR-C4 inflammasome activation, which provide evidence that Tim-3 signalling is critical for kidney IRI and may provide a new means to ameliorate kidney tissue immune responses in the clinics.
XPC gene mutations in families with xeroderma pigmentosum from Pakistan; prevalent founder effect
Authors: Ijaz Ambreen , Basit Sulman , Gul Ajab , Batool Lilas , Hussain Abrar , Afzal Sibtain , Ramzan Khushnooda , Ahmad Jamil , Wali Abdul
Published: March 2018

Xeroderma pigmentosum (XP) is a rare autosomal recessive skin disorder characterized by hyperpigmentation, premature skin aging, ocular and cutaneous photosensitivity, and increased risk of skin carcinoma. We investigated seven consanguineous XP families with nine patients from Pakistan. All the Patients exhibited typical clinical symptoms of XP since first year of life. Whole genome SNP genotyping identified a 14 Mb autozygous region segregating with the disease phenotype on chromosome 3p25.1. DNA sequencing of XPC gene revealed a founder homozygous splice site mutation (c.2251‐1G>C) in patients from six families (A–F) and a homozygous nonsense mutation (c.1399C>T; p.Gln467*) in patients of family G. This is the first report of XPC mutations, underlying XP phenotype, in Pakistani population.
Patients with perianal Crohn's fistulas experience delays in accessing anti‐TNF therapy due to slow recognition, diagnosis and integration of specialist services: lessons learned from three referral centres
Authors: Lee M. J. , Freer C. , Adegbola S. , Elkady S. , Parkes M. , Hart A. , Fearnhead N. S. , Lobo A. J. , Brown S. R.
Published: March 2018

Aim

Crohn's anal fistula should be managed by a multidisciplinary team. There is no clearly defined ‘patient pathway’ from presentation to treatment. The aim of this study was to describe the patient route from presentation with symptomatic Crohn's anal fistula to starting anti‐tumour necrosis factor (anti‐TNF) therapy.

Method

Case note review was undertaken at three hospitals with established inflammatory bowel disease services. Patients with Crohn's anal fistula presenting between 2010 and 2015 were identified through clinical coding and local databases. Baseline demographics were captured. Patient records were interrogated to identify route of access, and clinical contacts during the patient pathway.

Results

Seventy‐nine patients were included in the study, of whom 54 (68%) had an established diagnosis of Crohn's disease (CD). Median time from presentation to anti‐TNF therapy was 204 days (174 vs 365 days for existing and new diagnosis of CD, respectively; P = 0.019). The mean number of surgical outpatient attendances, operations and MRI scans per patient was 1.03, 1.71 and 1.03, respectively. Patients attended a mean of 1.49 medical clinics. Seton insertion was the most common procedure, accounting for 48.6% of all operations. Where care episodes (‘clinical events per 30 days’) were infrequent this correlated with prolongation of the pathway (r = −0.87; P < 0.01).

Conclusion

This study highlights two key challenges in the treatment pathway: (i) delays in diagnosis of underlying CD in patients with anal fistula and (ii) the pathway to anti‐TNF therapy is long, suggesting issues with service design and delivery. These should be addressed to improve patient experience and outcome.
Undifferentiated‐type component mixed with differentiated‐type early gastric cancer is a significant risk factor for endoscopic non‐curative resection
Authors: Horiuchi Yusuke , Fujisaki Junko , Yamamoto Noriko , Ishizuka Naoki , Omae Masami , Ishiyama Akiyoshi , Yoshio Toshiyuki , Hirasawa Toshiaki , Yamamoto Yorimasa , Nagahama Masatsugu , Takahashi Hiroshi , Tsuchida Tomohiro
Published: March 2018

Background and Aim

Previous studies of surgical specimens have found that the presence of mixed histological components in differentiated‐type early gastric cancer (EGC) is a risk factor for lymph node metastasis and indicates greater malignancy. As there have been no reports on its endoscopic treatment, we examined endoscopic curative resection in relation to differentiated‐type‐predominant mixed‐type (MT).

Methods

This was a single‐center, retrospective study. Subjects were 2585 differentiated‐type EGC in 2551 patients treated with endoscopic submucosal dissection (ESD) in our hospital between March 2005 and January 2016. These lesions comprised 2231 cases of curative resection and 354 cases of non‐curative resection. Histologically, 2339 lesions were pure differentiated‐type (PDT) and 246 lesions were MT. Rates of curative resection were compared, according to tumor size, between different histological types.

Results

When curative and non‐curative cases were compared using multivariate analysis among lesions measuring ≤20 mm for factors other than those determining curative resection, significant differences were obtained for tumor diameter, ulcer, and MT. Among lesions measuring 21–30 mm, ulcer and MT were associated with significant differences. Among lesions measuring >30 mm, upper region and MT were associated with significant differences. Curative resection rates, in relation to histological type among lesions measuring ≤20 mm, were 93.4% for PDT and 63.4% for MT, whereas corresponding rates were 85.1% and 60.0%, respectively, among lesions measuring 21–30 mm, and 55.3% and 30.2%, respectively, among lesions measuring >30 mm.

Conclusion

We found that MT was a risk factor for non‐curative resection irrespective of lesion size.
Have we done enough for people with fetal alcohol spectrum disorders?
Authors: Autti‐Rämö Ilona
Published: March 2018

This commentary is on the systematic review by Domeij et al. on pages 741–752 of this issue.
Rates of myocardial infarction and stroke in patients initiating treatment with SGLT2‐inhibitors versus other glucose‐lowering agents in real‐world clinical practice: Results from the CVD‐REAL study
Authors: Kosiborod Mikhail , Birkeland Kåre I. , Cavender Matthew A. , Fu Alex Z. , Wilding John P. , Khunti Kamlesh , Holl Reinhard W. , Norhammar Anna , Jørgensen Marit E. , Wittbrodt Eric T. , Thuresson Marcus , Bodegård Johan , Hammar Niklas , Fenici Peter ,   the CVD‐REAL Investigators and Study Group
Published: March 2018

The multinational, observational CVD‐REAL study recently showed that initiation of sodium‐glucose co‐transporter‐2 inhibitors (SGLT‐2i) was associated with significantly lower rates of death and heart failure vs other glucose‐lowering drugs (oGLDs). This sub‐analysis of the CVD‐REAL study sought to determine the association between initiation of SGLT‐2i vs oGLDs and rates of myocardial infarction (MI) and stroke. Medical records, claims and national registers from the USA, Sweden, Norway and Denmark were used to identify patients with T2D who newly initiated treatment with SGLT‐2i (canagliflozin, dapagliflozin or empagliflozin) or oGLDs. A non‐parsimonious propensity score was developed within each country to predict initiation of SGLT‐2i, and patients were matched 1:1 in the treatment groups. Pooled hazard ratios (HRs) and 95% CIs were generated using Cox regression models. Overall, 205 160 patients were included. In the intent‐to‐treat analysis, over 188 551 and 188 678 person‐years of follow‐up (MI and stroke, respectively), there were 1077 MI and 968 stroke events. Initiation of SGLT‐2i vs oGLD was associated with a modestly lower risk of MI and stroke (MI: HR, 0.85; 95%CI, 0.72‐1.00; P = .05; Stroke: HR, 0.83; 95% CI, 0.71‐0.97; P = .02). These findings complement the results of the cardiovascular outcomes trials, and offer additional reassurance with regard to the cardiovascular effects of SGLT‐2i, specifically as it relates to ischaemic events.
Ruptured mitral valve aneurysm: A devastating complication of aortic valve endocarditis
Authors: Hajsadeghi Shokoufeh , Marzban Mehrab , Joghataie Pegah , Iranpour Aida
Published: March 2018

Mitral valve aneurysm is a rare clinical entity that is mostly resulted from infective endocarditis, in particular, aortic valve endocarditis. Once mitral valve aneurysm ruptures and severe mitral regurgitation and hemodynamic instability develop, prompt surgery should be considered. Here we report a patient with ruptured mitral valve aneurysm associated with native aortic valve endocarditis that was improved after a successful mitral and aortic valve replacement surgery associated with antibiotic therapy for 6 weeks.
Usefulness of two‐ and three‐dimensional transesophageal echocardiography in combined mitral valve‐in‐valve implantation and paraprosthetic leak closure
Authors: Ahmed Mustafa I. , Arisha Mohammed J. , Nanda Navin C. , Lewis Clifton T. P. , Eudailey Kyle W.
Published: March 2018

We demonstrate the usefulness of two‐ and live/real time three‐dimensional transesophageal echocardiography in a procedure, which combined transcatheter mitral valve‐in‐valve deployment and paraprosthetic leak closure in the same setting using the less invasive transfemoral approach in an adult patient with bioprosthetic mitral valve degeneration. We also highlight the additive value of three‐dimensional echocardiography over the two‐dimensional technique.
The predictive value of global longitudinal strain on clinical outcome in patients with ST‐segment elevation myocardial infarction and preserved systolic function
Authors: Bendary Ahmed , Tawfeek Wael , Mahros Mohammed , Salem Mohamed
Published: March 2018

Background

Left ventricular ejection fraction (LVEF) is fundamental for risk stratification after ST‐segment elevation myocardial infarction (STEMI). However, it lacks discrimination power within normal range. Novel echocardiographic deformation parameters may be of benefit for those with post‐MI preserved LVEF.

Objectives

We hypothesized that semiautomated calculation of baseline global longitudinal strain (GLS) can identify high‐risk group among patients with LVEF ≥ 50% following STEMI.

Methods

During the period from January to July 2017, 110 patients with successful reperfusion of STEMI and LVEF ≥ 50% were prospectively included. Within 48 hours, patients underwent a baseline GLS study with follow‐up study at 30 days. The endpoint was a composite of cardiovascular mortality, rehospitalization for heart failure, and urgent revascularization.

Results

Mean GLS value changed from −16 ± 4% at baseline to −12 ± 4% at 30‐day follow‐up (P < .001). At 30 days, cardiovascular mortality was reported in 4.5%, 11.8% were rehospitalized due to heart failure, and 5.4% underwent urgent revascularization. ROC curve analysis showed that a cutoff baseline GLS value >−12.65% predicted 30‐day MACEs with a sensitivity and specificity of 77.8% and 83.7%, respectively (AUC 0.784, 95% CI 0.646–0.921, P < .001). An adjusted multivariate logistic regression analysis revealed that baseline GLS value >−12.65% to be the only significant independent predictor for occurrence of MACEs (OR 19.54, 95% CI 6.3–61.1, P < .001).

Conclusion

Early GLS calculation predicts 30‐day outcome in patients with preserved LVEF following reperfusion of STEMI.
Canadian butterfly climate debt is significant and correlated with range size
Authors: Lewthwaite J. M. M. , Angert A. L. , Kembel S. W. , Goring S. J. , Davies T. J. , Mooers A. Ø. , Sperling F. A. H. , Vamosi S. M. , Vamosi J. C. , Kerr J. T.
Published: March 2018

Climate change is causing rapid shifts in species’ range limits, leading to poleward expansions and range losses toward the equator. However, ‘climate debt’, the gap between required and realized range shifts under changing climates, can accumulate when species are unable to track shifting conditions sufficiently rapidly to keep pace with climate changes. Currently, we do not know the rate at which species will keep pace via dispersal to track their climate envelopes, yet understanding potential differences in climate debt is central to estimating how climate change will influence extinction risk. Here, we use historical observations of 155 butterfly species found in Canada to construct climate‐based environmental niche models for each species and then compare projections with observed modern distributions to quantify climate debts. This approach suggests that high levels of climate debt are accumulating within the vast majority of these species. Such failure to track changing climates may arise from some combination of interspecific interactions such as particular food availability for specialists, abiotic barriers such as mountain ranges, or species’ intrinsic dispersal capacities. Our linear models relating climate debt to a variety of biological predictors suggest that the debts we documented are accumulating independently of dispersal ability, diet breadth, and phylogeny. A proxy for range size is the only significant predictor of climate debt, with species with narrower ranges accumulating more debt: this suggests that species with narrow ranges may be at risk from both a reduction of suitable habitat in their current range and the failure to colonize newly available habitat. Identifying the factors, whether intrinsic or imposed by local environmental conditions, that limit species’ capacities to colonize areas beyond their historical limits is vital to conservation planning.
Within‐species patterns challenge our understanding of the leaf economics spectrum
Authors: Anderegg Leander D. L. , Berner Logan T. , Badgley Grayson , Sethi Meera L. , Law Beverly E. , HilleRisLambers Janneke
Published: March 2018

The utility of plant functional traits for predictive ecology relies on our ability to interpret trait variation across multiple taxonomic and ecological scales. Using extensive data sets of trait variation within species, across species and across communities, we analysed whether and at what scales leaf economics spectrum (LES) traits show predicted trait–trait covariation. We found that most variation in LES traits is often, but not universally, at high taxonomic levels (between families or genera in a family). However, we found that trait covariation shows distinct taxonomic scale dependence, with some trait correlations showing opposite signs within vs. across species. LES traits responded independently to environmental gradients within species, with few shared environmental responses across traits or across scales. We conclude that, at small taxonomic scales, plasticity may obscure or reverse the broad evolutionary linkages between leaf traits, meaning that variation in LES traits cannot always be interpreted as differences in resource use strategy.
The taphonomic fate of isorenieratene in Lower Jurassic shales—controlled by iron?
Authors: Reinhardt M. , Duda J.‐P. , Blumenberg M. , Ostertag‐Henning C. , Reitner J. , Heim C. , Thiel V.
Published: March 2018

Fossil derivatives of isorenieratene, an accessory pigment in brown‐colored green sulfur bacteria, are often used as tracers for photic zone anoxia through Earth's history, but their diagenetic behavior is still incompletely understood. Here, we assess the preservation of isorenieratene derivatives in organic‐rich shales (1.5–8.4 wt.% TOC) from two Lower Jurassic anoxic systems (Bächental oil shale, Tyrol, Austria; Posidonia Shale, Baden‐Württemberg, Germany). Bitumens and kerogens were investigated using catalytic hydropyrolysis (HyPy), closed‐system hydrous pyrolysis (in gold capsules), gas chromatography–mass spectrometry (GC–MS) and gas chromatography combustion isotope ratio‐mass spectrometry (GC‐C‐IRMS). Petrography and biomarkers indicate a syngenetic relationship between bitumens and kerogens. All bitumens contain abundant isorenieratane, diverse complex aromatized isorenieratene derivatives, and a pseudohomologous series of 2,3,6‐trimethyl aryl isoprenoids. In contrast, HyPy and mild closed‐system hydrous pyrolysis of the kerogens yielded only minor amounts of these compounds. Given the overall low maturity of the organic matter (below oil window), it appears that isorenieratene and its abundant derivatives from the bitumen had not been incorporated into the kerogens. Accordingly, sulfur cross‐linking, the key mechanism for sequestration of functionalized lipids into kerogens in anoxic systems, was not effective in the Jurassic environments studied. We explain this by (i) early cyclization/aromatization and (ii) hydrogenation reactions that have prevented effective sulfurization. In addition, (iii) sulfide was locally removed via anoxygenic photosynthesis and efficiently trapped by the reaction with sedimentary iron, as further indicated by elevated iron contents (4.0–8.7 wt.%) and the presence of abundant pyrite aggregates in the rock matrix. Although the combined processes have hampered the kerogen incorporation of isorenieratene and its derivatives, they may have promoted the long‐term preservation of these biomarkers in the bitumen fraction via early defunctionalization. This particular taphonomy of aromatic carotenoids has to be considered in studies of anoxic iron‐rich environments (e.g., the Proterozoic ocean).
Time lag and negative responses of forest greenness and tree growth to warming over circumboreal forests
Authors: Tei Shunsuke , Sugimoto Atsuko
Published: March 2018

The terrestrial forest ecosystems in the northern high latitude region have been experiencing significant warming rates over several decades. These forests are considered crucial to the climate system and global carbon cycle and are particularly vulnerable to climate change. To obtain an improved estimate of the response of vegetation activity, e.g., forest greenness and tree growth, to climate change, we investigated spatiotemporal variations in two independent data sets containing the dendroecological information for this region over the past 30 years. These indices are the normalized difference vegetation index (NDVI3g) and the tree‐ring width index (RWI), both of which showed significant spatial variability in past trends and responses to climate changes. These trends and responses to climate change differed significantly in the ecosystems of the circumarctic (latitude higher than 67°N) and the circumboreal forests (latitude higher and lower than 50°N and 67°N, respectively), but the way in which they differed was relatively similar in the NDVI3g and the RWI. In the circumarctic ecosystem, the climate variables of the current summer were the main climatic drivers for the positive response to the increase in temperatures showed by both the NDVI3g and the RWI indices. On the other hand, in the circumboreal forest ecosystem, the climate variables of the previous year (from summer to winter) were also important climatic drivers for both the NDVI3g and the RWI. Importantly, both indices showed that the temperatures in the previous year negatively affected the ecosystem. Although such negative responses to warming did not necessarily lead to a past negative linear trend in the NDVI3g and the RWI over the past 30 years, future climate warming could potentially cause severe reduction in forest greenness and tree growth in the circumboreal forest ecosystem.
Nongrowing season methane emissions–a significant component of annual emissions across northern ecosystems
Authors: Treat Claire C. , Bloom A. Anthony , Marushchak Maija E.
Published: March 2018

Wetlands are the single largest natural source of atmospheric methane (CH4), a greenhouse gas, and occur extensively in the northern hemisphere. Large discrepancies remain between “bottom‐up” and “top‐down” estimates of northern CH4 emissions. To explore whether these discrepancies are due to poor representation of nongrowing season CH4 emissions, we synthesized nongrowing season and annual CH4 flux measurements from temperate, boreal, and tundra wetlands and uplands. Median nongrowing season wetland emissions ranged from 0.9 g/m2 in bogs to 5.2 g/m2 in marshes and were dependent on moisture, vegetation, and permafrost. Annual wetland emissions ranged from 0.9 g m−2 year−1 in tundra bogs to 78 g m−2 year−1 in temperate marshes. Uplands varied from CH4 sinks to CH4 sources with a median annual flux of 0.0 ± 0.2 g m−2 year−1. The measured fraction of annual CH4 emissions during the nongrowing season (observed: 13% to 47%) was significantly larger than that was predicted by two process‐based model ensembles, especially between 40° and 60°N (modeled: 4% to 17%). Constraining the model ensembles with the measured nongrowing fraction increased total nongrowing season and annual CH4 emissions. Using this constraint, the modeled nongrowing season wetland CH4 flux from >40° north was 6.1 ± 1.5 Tg/year, three times greater than the nongrowing season emissions of the unconstrained model ensemble. The annual wetland CH4 flux was 37 ± 7 Tg/year from the data‐constrained model ensemble, 25% larger than the unconstrained ensemble. Considering nongrowing season processes is critical for accurately estimating CH4 emissions from high‐latitude ecosystems, and necessary for constraining the role of wetland emissions in a warming climate.
How will climate novelty influence ecological forecasts? Using the Quaternary to assess future reliability
Authors: Fitzpatrick Matthew C. , Blois Jessica L. , Williams John W. , Nieto‐Lugilde Diego , Maguire Kaitlin C. , Lorenz David J.
Published: March 2018

Future climates are projected to be highly novel relative to recent climates. Climate novelty challenges models that correlate ecological patterns to climate variables and then use these relationships to forecast ecological responses to future climate change. Here, we quantify the magnitude and ecological significance of future climate novelty by comparing it to novel climates over the past 21,000 years in North America. We then use relationships between model performance and climate novelty derived from the fossil pollen record from eastern North America to estimate the expected decrease in predictive skill of ecological forecasting models as future climate novelty increases. We show that, in the high emissions scenario (RCP 8.5) and by late 21st century, future climate novelty is similar to or higher than peak levels of climate novelty over the last 21,000 years. The accuracy of ecological forecasting models is projected to decline steadily over the coming decades in response to increasing climate novelty, although models that incorporate co‐occurrences among species may retain somewhat higher predictive skill. In addition to quantifying future climate novelty in the context of late Quaternary climate change, this work underscores the challenges of making reliable forecasts to an increasingly novel future, while highlighting the need to assess potential avenues for improvement, such as increased reliance on geological analogs for future novel climates and improving existing models by pooling data through time and incorporating assemblage‐level information.
Coral bleaching is linked to the capacity of the animal host to supply essential metals to the symbionts
Authors: Ferrier‐Pagès Christine , Sauzéat Lucie , Balter Vincent
Published: March 2018

Massive coral bleaching events result in extensive coral loss throughout the world. These events are mainly caused by seawater warming, but are exacerbated by the subsequent decrease in nutrient availability in surface waters. It has therefore been shown that nitrogen, phosphorus or iron limitation contribute to the underlying conditions by which thermal stress induces coral bleaching. Generally, information on the trophic ecology of trace elements (micronutrients) in corals, and on how they modulate the coral response to thermal stress is lacking. Here, we demonstrate for the first time that heterotrophic feeding (i.e. the capture of zooplankton prey by the coral host) and thermal stress induce significant changes in micro element concentrations and isotopic signatures of the scleractinian coral Stylophora pistillata. The results obtained first reveal that coral symbionts are the major sink for the heterotrophically acquired micronutrients and accumulate manganese, magnesium and iron from the food. These metals are involved in photosynthesis and antioxidant protection. In addition, we show that fed corals can maintain high micronutrient concentrations in the host tissue during thermal stress and do not bleach, whereas unfed corals experience a significant decrease in copper, zinc, boron, calcium and magnesium in the host tissue and bleach. In addition, the significant increase in δ65Cu and δ66Zn signature of symbionts and host tissue at high temperature suggests that these isotopic compositions are good proxy for stress in corals. Overall, present findings highlight a new way in which coral heterotrophy and micronutrient availability contribute to coral resistance to global warming and bleaching.
Nitrogen deposition outweighs climatic variability in driving annual growth rate of canopy beech trees: Evidence from long‐term growth reconstruction across a geographic gradient
Authors: Gentilesca Tiziana , Rita Angelo , Brunetti Michele , Giammarchi Francesco , Leonardi Stefano , Magnani Federico , van Noije Twan , Tonon Giustino , Borghetti Marco
Published: March 2018

In this study, we investigated the role of climatic variability and atmospheric nitrogen deposition in driving long‐term tree growth in canopy beech trees along a geographic gradient in the montane belt of the Italian peninsula, from the Alps to the southern Apennines. We sampled dominant trees at different developmental stages (from young to mature tree cohorts, with tree ages spanning from 35 to 160 years) and used stem analysis to infer historic reconstruction of tree volume and dominant height. Annual growth volume (GV) and height (GH) variability were related to annual variability in model simulated atmospheric nitrogen deposition and site‐specific climatic variables, (i.e. mean annual temperature, total annual precipitation, mean growing period temperature, total growing period precipitation, and standard precipitation evapotranspiration index) and atmosphericCO2concentration, including tree cambial age among growth predictors. Generalized additive models (GAM), linear mixed‐effects models (LMM), and Bayesian regression models (BRM) were independently employed to assess explanatory variables. The main results from our study were as follows: (i) tree age was the main explanatory variable for long‐term growth variability; (ii)GAM,LMM, andBRMresults consistently indicated climatic variables andCO2effects onGVandGHwere weak, therefore evidence of recent climatic variability influence on beech annual growth rates was limited in the montane belt of the Italian peninsula; (iii) instead, significant positive nitrogen deposition (Ndep) effects were repeatedly observed inGVandGH; the positive effects of Ndepon canopy height growth rates, which tended to level off at Ndepvalues greater than approximately 1.0 g m−2 y−1, were interpreted as positive impacts on forest stand above‐ground net productivity at the selected study sites.
Large uncertainty in carbon uptake potential of land‐based climate‐change mitigation efforts
Authors: Krause Andreas , Pugh Thomas A. M. , Bayer Anita D. , Li Wei , Leung Felix , Bondeau Alberte , Doelman Jonathan C. , Humpenöder Florian , Anthoni Peter , Bodirsky Benjamin L. , Ciais Philippe , Müller Christoph , Murray‐Tortarolo Guillermo , Olin Stefan , Popp Alexander , Sitch Stephen , Stehfest Elke , Arneth Almut
Published: March 2018

Most climate mitigation scenarios involve negative emissions, especially those that aim to limit global temperature increase to 2°C or less. However, the carbon uptake potential in land‐based climate change mitigation efforts is highly uncertain. Here, we address this uncertainty by using two land‐based mitigation scenarios from two land‐use models (IMAGE and MAgPIE) as input to four dynamic global vegetation models (DGVMs; LPJ‐GUESS, ORCHIDEE, JULES, LPJmL). Each of the four combinations of land‐use models and mitigation scenarios aimed for a cumulative carbon uptake of ~130 GtC by the end of the century, achieved either via the cultivation of bioenergy crops combined with carbon capture and storage (BECCS) or avoided deforestation and afforestation (ADAFF). Results suggest large uncertainty in simulated future land demand and carbon uptake rates, depending on the assumptions related to land use and land management in the models. Total cumulative carbon uptake in the DGVMs is highly variable across mitigation scenarios, ranging between 19 and 130 GtC by year 2099. Only one out of the 16 combinations of mitigation scenarios and DGVMs achieves an equivalent or higher carbon uptake than achieved in the land‐use models. The large differences in carbon uptake between the DGVMs and their discrepancy against the carbon uptake in IMAGE and MAgPIE are mainly due to different model assumptions regarding bioenergy crop yields and due to the simulation of soil carbon response to land‐use change. Differences between land‐use models and DGVMs regarding forest biomass and the rate of forest regrowth also have an impact, albeit smaller, on the results. Given the low confidence in simulated carbon uptake for a given land‐based mitigation scenario, and that negative emissions simulated by the DGVMs are typically lower than assumed in scenarios consistent with the 2°C target, relying on negative emissions to mitigate climate change is a highly uncertain strategy.
Influence of temperature, calcium and sucrose concentration on viscoelastic properties of Prosopis chilensis seed gum and nopal mucilage dispersions
Authors: Tabilo‐Munizaga Gipsy , Sáenz‐Hernández Carmen , Herrera‐Lavados Carolina
Published: March 2018

Viscoelastic properties of two nontraditional hydrocolloid dispersions were evaluated. Prosopis chilensis seed gum was evaluated based on temperature (5–80 °C) and added CaCl2 (0.07%), whereas nopal mucilage was evaluated based on temperature (5–80 °C) and sucrose concentration (0–20%). Viscoelasticity was tested by the small strain oscillatory shear test; storage modulus (G′), loss modulus (G″) and tan δ were reported. Prosopis chilensis and nopal dispersions behaved as weak gels (G’ > G’’) regardless of experimental condition. Raising temperature from 20 to 80 °C significantly increased G’. The gel structure was strengthened by adding CaCl2 and G’ increased at 40 °C. The sucrose effect depended on concentration and temperature; at low sucrose concentrations, G’ modulus increased regardless of temperature level, but at high concentrations, it decreased at temperatures >40 °C. In conclusion, nopal and Prosopis chilensis dispersions show weak gel structure regardless of experimental condition. G′ increases as temperature increases, and these dispersions could be suitable for food applications requiring heat tolerance.
Development and validation of a neural network model for predicting growth of Salmonella Newport on diced Roma tomatoes during simulated salad preparation and serving: extrapolation to other serotypes
Authors: Oscar Thomas P.
Published: March 2018

A study was undertaken to model growth of Salmonella on tomatoes for developing and validating a predictive model for use in risk assessment. Cylindrical portions (0.14 g) of Roma tomato pulp were inoculated with a low dose (0.89 log MPN) of Salmonella Newport. The inoculated tomato portions were incubated for 0–8 h at 16–40 °C in 2 °C increments to obtain most probable number (MPN) data for model development and validation. A multiple‐layer feedforward neural network model with two hidden layers of two nodes each was developed. The proportion of residuals in an acceptable prediction zone (pAPZ) from −1 (fail‐safe) to 0.5 log (fail‐dangerous) was 0.93 (194/209) for dependent data and 0.96 (86/90) for independent data for interpolation. A pAPZ ≥0.7 indicated that the model provided acceptable predictions. Thus, the model was successfully validated. It was also validated for extrapolation to seven other Salmonella serotypes.
The effect of sleep hygiene education and relaxation exercises on insomnia among postmenopausal women: A randomized clinical trial
Authors: Duman Mesude , Timur Taşhan Sermin
Published: March 2018

Aim

This study used a randomized controlled trial model to determine the effect of progressive relaxation exercises and sleep hygiene training given to postmenopausal women with insomnia.

Methods

A total of 161 postmenopausal women with insomnia were recruited and randomly assigned to experimental (n = 81) and control (n = 80) groups. The experimental group received sleep hygiene and progressive relaxation exercise training, but the control group only received routine health care. The relaxation exercise training was repeated once a week for 8 weeks. The study determined the effect of the intervention on insomnia symptoms. The data were collected between 15 June and 15 September 2015 and evaluated using descriptive statistics, independent samples t‐test, chi‐squared test, and Cronbach alpha analysis.

Results

The mean (SD) score of the experimental group on the Women's Health Initiative Insomnia Rating Scale was 14.03 (3.4) pretest and 7.09 (3.4) posttest. The difference between the pretest and posttest scores was statistically significant (P < .001), as was the difference between the rates of insomnia symptoms between the groups posttest (P < .001).

Conclusion

The findings of study suggest that nurses teaching progressive relaxation exercises and sleep hygiene would benefit postmenopausal women who suffer from insomnia.
Development of mucosal‐associated invariant T cells
Authors: Koay Hui‐Fern , Godfrey Dale I , Pellicci Daniel G
Published: March 2018

Mucosal‐associated invariant T (MAIT) cells develop in the thymus and migrate into the periphery to become the largest antigen‐specific αβ T‐cell population in the human immune system. However, the frequency of MAIT cells varies widely between human individuals, and the basis for this is unclear. While MAIT cells are highly conserved through evolution and are phenotypically similar between humans and mice, they represent a much smaller proportion of total T cells in mice. In this review, we discuss how MAIT cells transition through a three‐stage development pathway in both mouse and human thymus, and continue to mature and expand after they leave the thymus. Moreover, we will explore and speculate on how specific factors regulate different stages of this process.