bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multivariate mapping of soil with structural equation modelling
Authors: Angelini M. E. , Heuvelink G. B. M. , Kempen B. 
Published: July 2017

SummaryIn a previous study we introduced structural equation modelling (SEM) for digital soil mapping in the Argentine Pampas. An attractive property of SEM is that it incorporates pedological knowledge explicitly through a mathematical implementation of a conceptual model. Many soil processes operate within the soil profile; therefore, SEM might be suitable for simultaneous prediction of soil properties for multiple soil layers. In this way, relations between soil properties in different horizons can be included that might result in more consistent predictions. The objectives of this study were therefore to apply SEM to multi‐layer and multivariate soil mapping, and to test SEM functionality for suggestions to improve the modelling. We applied SEM to model and predict the lateral and vertical distribution of the cation exchange capacity (CEC), organic carbon (OC) and clay content of three major soil horizons, A, B and C, for a 23 000‐km2 region in the Argentine Pampas. We developed a conceptual model based on pedological hypotheses. Next, we derived a mathematical model and calibrated it with environmental covariates and soil data from 320 soil profiles. Cross‐validation of predicted soil properties showed that SEM explained only marginally more of the variance than a linear regression model. However, assessment of the covariation showed that SEM reproduces the covariance between variables much more accurately than linear regression. We concluded that SEM can be used to predict several soil properties in multiple layers by considering the interrelations between soil properties and layers.HighlightsWe tested structural equation modelling (SEM) for multi‐layer and multivariate soil mapping.
SEM models soil property covariation better than multiple linear regression.
The SEM re‐specification step improves prediction accuracy.
SEM supports learning about soil processes from data.
The rove beetle Drusilla sparsa (Coleoptera: Staphylinidae) is a myrmecophilous species associated with a myrmicine ant, Crematogaster osakensis (Hymenoptera: Formicidae)
Authors: Ikeshita Yohei , Taniguchi Kentaro , Kitagawa Yuji , Maruyama Munetoshi , Ito Fuminori 
Published: July 2017

AbstractThe rove beetle genus Drusilla includes some myrmecophilous species. The Japanese species Drusilla sparsa (Sharp, 1874) has been regarded as a non‐myrmecophilous beetle. In Kagawa Prefecture, Shikoku Island, western Japan, however, we often observed that D. sparsa adults were walking in the vicinity of foraging workers of the myrmicine ant Crematogaster osakensis Forel, 1990. The body color of the beetle is similar to C. osakensis as in other myrmecophilous beetles found near the trails of the host ants. To examine whether D. sparsa is myrmecophilous, we investigated the distribution of D. sparsa and C. osakensis in the field, as well as their behavior including prey preference of the beetle in the laboratory. Drusilla sparsa beetles were collected only in sites where C. osakensis ants occurred. When the beetles encountered the ant workers, they bent the abdominal tip toward the ants. The ants licked the abdominal tip, and then the beetles usually walked away. Such behavioral reaction of the ants was not observed when the beetles encountered workers of the formicine ant Nylanderia flavipes (Smith, 1874) that continuously attacked the beetles. Drusilla sparsa preferred to feed on dead workers of C. osakensis even when other ants were available as food, indicating that D. sparsa is a myrmecophilous species associated with C. osakensis. Crematogaster osakensis was frequently found in the stomach in the ant predator, the Japanese treefrog Hyla japonica Günther, 1859. Thus, the significance of body color similarity between the host ants and beetles is not a case of Batesian mimicry.
Voxel‐based magnetic resonance image postprocessing in epilepsy
Authors: Martin Pascal , Winston Gavin P. , Bartlett Philippa , de Tisi Jane , Duncan John S. , Focke Niels K. 
Published: July 2017

SummaryObjectiveAlthough the general utility of voxel‐based processing of structural magnetic resonance imaging (MRI) data for detecting occult lesions in focal epilepsy is established, many differences exist among studies, and it is unclear which processing method is preferable. The aim of this study was to compare the ability of commonly used methods to detect epileptogenic lesions in magnetic resonance MRI‐positive and MRI‐negative patients, and to estimate their diagnostic yield.MethodsWe identified 144 presurgical focal epilepsy patients, 15 of whom had a histopathologically proven and MRI‐visible focal cortical dysplasia; 129 patients were MRI negative with a clinical hypothesis of seizure origin, 27 of whom had resections. We applied four types of voxel‐based morphometry (VBM), three based on T1 images (gray matter volume, gray matter concentration, junction map [JM]) and one based on normalized fluid‐attenuated inversion recovery (nFSI). Specificity was derived from analysis of 50 healthy controls.ResultsThe four maps had different sensitivity and specificity profiles. All maps showed detection rates for focal cortical dysplasia patients (MRI positive and negative) of >30% at a strict threshold of p < 0.05 (family‐wise error) and >60% with a liberal threshold of p < 0.0001 (uncorrected), except for gray matter volume (14% and 27% detection rate). All maps except nFSI showed poor specificity, with high rates of false‐positive findings in controls. In the MRI‐negative patients, absolute detection rates were lower. A concordant nFSI finding had a significant positive odds ratio of 7.33 for a favorable postsurgical outcome in the MRI‐negative group. Spatial colocalization of JM and nFSI was rare, yet showed good specificity throughout the thresholds.SignificanceAll VBM variants had specific diagnostic properties that need to be considered for an adequate interpretation of the results. Overall, structural postprocessing can be a useful tool in presurgical diagnostics, but the low specificity of some maps has to be taken into consideration.
Male territorial aggression does not drive conformity to local vocal culture in a passerine bird
Authors: Parra Marcelina , Dalisio Anthony C. , Jensen William E. , Parker Timothy H. 
Published: July 2017

AbstractIn many songbird species, young individuals learn songs from neighbors and then settle nearby, thus creating neighborhoods of conformity to local vocal culture. In some species, individuals appear to postpone song learning until after dispersal, possibly to facilitate conformity to local dialects. Despite decades of study, we still lack a consensus regarding the selective pressures driving this delayed song learning. Two common hypothetical benefits to conformity, and thus delayed song learning, are rooted in territorial interactions; individuals preferentially produce local song either to avoid detection as new arrivals (deceptive mimicry) or to be more effectively recognized as conspecific territory holders. The dickcissel (Spiza americana) is an ideal species in which to study these hypotheses. Males of this species appear to delay song learning until they arrive at their first adult territory, each individual sings a single song type, and conformity to the local song culture is high. Using playback, we contradicted both of the territorial hypotheses described above; male dickcissels did not respond differentially to local vs foreign song playback treatment. We are confident in this lack of difference because dickcissels clearly responded less strongly to a third treatment, neighbor song, than to the other two treatments, demonstrating sufficient power in our experimental design (and providing the first evidence of the dear‐enemy effect in dickcissels). Our results raise the question of why dickcissels respond equally aggressively to both local and foreign songs when other bird species often show reduced aggression toward foreign song. If reduced aggression to foreign song is not ubiquitous in species that achieve conformity through delayed learning, then selection from aggressive territorial interaction seems unlikely to be a general explanation for such delayed learning. Reduced aggression in response to foreign songs in other species may be due to reduced exposure to the stimulus of foreign song or to different cost‐benefit trade‐offs when responding to songs that deviate from the local average.
What is driving male mate preference evolution in Jamaican field crickets?
Authors: Bertram Susan M. , Harrison Sarah J. , Ferguson Genevieve L. , Thomson Ian R. , Loranger Michelle J. , Reifer Mykell L. , Corlett Deborah H. , Gowaty Patricia Adair 
Published: July 2017

ABSTRACTMale mating preferences are often a neglected aspect of studies on sexual selection. Male mating preferences may evolve if they provide males with direct‐fitness benefits such as increased opportunity to fertilize more eggs or indirect‐fitness benefits such as enhanced offspring survival. We tested these ideas using Jamaican field crickets, Gryllus assimilis, previously shown to exhibit male mating preferences. We randomly mated males to either their preferred or non‐preferred potential mates and then asked whether mating treatment influenced egg oviposition or offspring viability. Preferred females were not significantly more fecund and did not produce more viable eggs or offspring than non‐preferred females. Male mate preferences were therefore inconsistent with both the direct‐ and indirect‐fitness benefits hypotheses under the conditions of our experiment. Our null results leave us with an open question about what is driving the evolution of mating preferences in male crickets. Future research should explore the whether the offspring of preferred females are more attractive, have stronger immune systems, and/or experience higher adult longevity.
Personality predicts ectoparasite abundance in an asocial sciurid
Authors: Bohn Shelby J. , Webber Quinn M. R. , Florko Katie R. N. , Paslawski Katlyn R. , Peterson Amelia M. , Piche Julia E. , Menzies Allyson K. , Willis Craig K. R. 
Published: July 2017

AbstractParasitism is a consequence of complex interactions between host, parasite, and their shared environment, and host behavior can influence parasite risk. Animal personality (i.e., consistent behavioral differences that are repeatable across time and context) can influence parasitism with more explorative individuals typically hosting greater parasite loads. Host “sociality” is known to impact parasite risk with more social individuals typically at higher risk of acquiring or transmitting parasites, but other behaviors could also be important. We quantified personality in least chipmunks (Tamias minimus), including repeatability of behavioral traits, and determined whether these personality traits affected ectoparasite prevalence and abundance. We measured personality using standardized hole‐board tests and quantified ectoparasitism of 39 least chipmunks over 2 years at a site in southeastern Manitoba, Canada. We found that activity and exploration were repeatable within the context of the hole‐board test for least chipmunks, which suggests that these traits reflect personality. More exploratory individuals hosted a greater abundance of ectoparasites compared to less exploratory individuals. Our results are consistent with past studies implicating personality as a factor in host–parasite dynamics and suggest that exploration may be an important behavioral correlate of parasite acquisition.
Amphibian species traits, evolutionary history and environment predict Batrachochytrium dendrobatidis infection patterns, but not extinction risk
Authors: Greenberg Dan A. , Palen Wendy J. , Mooers Arne Ø. 
Published: July 2017

AbstractThe fungal pathogen Batrachochytrium dendrobatidis (B. dendrobatidis) has emerged as a major agent of amphibian extinction, requiring conservation intervention for many susceptible species. Identifying susceptible species is challenging, but many aspects of species biology are predicted to influence the evolution of host resistance, tolerance, or avoidance strategies towards disease. In turn, we may expect species exhibiting these distinct strategies to differ in their ability to survive epizootic disease outbreaks. Here, we test for phylogenetic and trait‐based patterns of B. dendrobatidis infection risk and infection intensity among 302 amphibian species by compiling a global data set of B. dendrobatidis infection surveys across 95 sites. We then use best‐fit models that associate traits, taxonomy and environment with B. dendrobatidis infection risk and intensity to predict host disease mitigation strategies (tolerance, resistance, avoidance) for 122 Neotropical amphibian species that experienced epizootic B. dendrobatidis outbreaks, and noted species persistence or extinction from these events. Aspects of amphibian species life history, habitat use and climatic niche were consistently linked to variation in B. dendrobatidis infection patterns across sites around the world. However, predicted B. dendrobatidis infection risk and intensity based on site environment and species traits did not reveal a consistent pattern between the predicted host disease mitigation strategy and extinction outcome. This suggests that either tolerant or resistant species may have no advantage in ameliorating disease during epizootic events, or that other factors drive the persistence of amphibian populations during chytridiomycosis outbreaks. These results suggest that using a trait‐based approach may allow us to identify species with resistance or tolerance to endemic B. dendrobatidis infections, but that this approach may be insufficient to ultimately identify species at risk of extinction from epizootics.
Application of continuum damage mechanics to vibration fatigue life prediction
Authors: Li Yi , Sun Bing , Fang Jie , Liu Xue‐Feng , Liang Tong , Cai Guo‐Biao 
Published: July 2017

AbstractIt is pivotal to predict the multiaxial vibration fatigue life during mechanical structural dynamics design. An algorithm of the finite element method implementation for multiaxial high cycle fatigue life evaluation is proposed, on the basis of elastic evolution model of continuum damage mechanics. By considering structural dynamic characteristics, namely, resonant frequencies and mode shapes, this algorithm includes a modal analysis and harmonic analysis, which makes this different from existing fatigue life prediction methods. A 10% decrease in the resonant frequency is regarded as the failure criterion. A critical damage value was obtained, which indicates mesocrack initiation fulfilment. To validate the effectiveness of the algorithm, auto‐phase sine resonance track‐and‐dwell experiments were conducted on notched cantilever beams made of Ti‐6Al‐4V alloy. The life predictions are conservative and in good agreements with the experimental results, which are mainly distributed within a scatter band of 2. This investigation could provide technical support for structural dynamics design and the analysis of reusable spacecraft.
A weight function method for mixed modes hole‐edge cracks
Authors: Xu W. , Wu X.R. , Yu Y. , Li Z.H. 
Published: July 2017

AbstractA weight function approach is proposed to calculate the stress intensity factor and crack opening displacement for cracks emanating from a circular hole in an infinite sheet subjected to mixed modes load. The weight function for a pure mode II hole‐edge crack is given in this paper. The stress intensity factors for a mixed modes hole‐edge crack are obtained by using the present mode II weight function and existing mode I Green (weight) function for a hole‐edge crack. Without complex derivation, the weight functions for a single hole‐edge crack and a centre crack in infinite sheets are used to study 2 unequal‐length hole‐edge cracks. The stress intensity factor and crack opening displacement obtained from the present weight function method are compared well with available results from literature and finite element analysis. Compared with the alternative methods, the present weight function approach is simple, accurate, efficient, and versatile in calculating the stress intensity factor and crack opening displacement.
Spatial evaluation of Indonesia's 2015 fire‐affected area and estimated carbon emissions using Sentinel‐1
Authors: Lohberger Sandra , Stängel Matthias , Atwood Elizabeth C. , Siegert Florian 
Published: July 2017

AbstractFires raged once again across Indonesia in the latter half of 2015, creating a state of emergency due to poisonous smoke and haze across Southeast Asia as well as incurring great financial costs to the government. A strong El Niño‐Southern Oscillation (ENSO) led to drought in many parts of Indonesia, resulting in elevated fire occurrence comparable with the previous catastrophic event in 1997/1998. Synthetic Aperture Radar (SAR) data promise to provide improved detection of land use and land cover changes in the tropics as compared to methodologies dependent upon cloud‐ and haze‐free images. This study presents the first spatially explicit estimates of burned area across Sumatra, Kalimantan, and West Papua based on high‐resolution Sentinel‐1A SAR imagery. Here, we show that 4,604,569 hectares (ha) were burned during the 2015 fire season (overall accuracy 84%), and compare this with other existing operational burned area products (MCD64, GFED4.0, GFED4.1s). Intersection of burned area with fine‐scale land cover and peat layer maps indicates that 0.89 gigatons carbon dioxide equivalents (Gt CO2e) were released through the fire event. This result is compared to other estimates based on nonspatially explicit thermal anomaly measurements or atmospheric monitoring. Using freely available SAR C‐band data from the Sentinel mission, we argue that the presented methodology is able to quickly and precisely detect burned areas, supporting improvement in fire control management as well as enhancing accuracy of emissions estimation.
Predicted factors for older Taiwanese to be healthy octogenarians: Results of an 18‐year national cohort study
Authors: Hsu Wei‐Chung , Tsai Alan C. , Chen Yu‐Chia , Wang Jiun‐Yi 
Published: July 2017

AbstractAimTo identify factors that predict the 62–69 years old Taiwanese to be healthy octogenarians.MethodsWe analyzed the 1989 (baseline), and 2003 and 2007 (end‐point) datasets of the Taiwan Longitudinal Survey on Aging, a national cohort study. A total of 1977 participants aged 62–69 years at baseline were tracked for 14–18 years. The outcome measure was “being healthy octogenarians”, defined as participants who were aged ≥80 years, free from activities of daily living dependency, depressive symptoms or cognitive impairment, and able to provide social support. A logistic regression model was used to identify the predictors.ResultsThe results showed that higher educational level, conjugal living, absence of smoking or betel quid chewing, moderate alcohol drinking, routine physical activity, more leisure activities, no hypertension, no diabetes, sleeping well and satisfied with economic condition were the positive predictors for becoming a healthy octogenarian.ConclusionsUsing a multidimensional criterion, the present study identified a list of factors in predicting older Taiwanese becoming healthy octogenarians. The findings highlight the need to identify potential factors for various populations. Many of the predictors are modifiable factors. The present results would be valuable for planning effective health promotion strategies to achieve healthy aging for older adults. Geriatr Gerontol Int 2017; 17: 2579–2585.
Digital image analysis of HER2 immunohistochemistry in gastric‐ and oesophageal adenocarcinoma: a validation study on biopsies and surgical specimens
Authors: Koopman Timco , de Bock Geertruida H , Buikema Henk J , Smits Maria M , Louwen Maarten , Hage Mariska , Imholz Alex L T , van der Vegt Bert 
Published: July 2017

AimsTo test the validity of diagnostics incorporating digital image analysis (DIA) for human epidermal growth factor 2 (HER2) immunohistochemistry (IHC) in gastro‐oesophageal adenocarcinomas, as an alternative to current standard diagnostics using manual scoring.Methods and resultsWe included 319 consecutive gastro‐oesophageal adenocarcinomas (232 biopsies and 87 surgical specimens). DIA was applied to determine HER2 IHC classification, using both standard breast cancer (BC) and modified gastro‐oesophageal cancer (GEC) cut‐offs. Consensus manual scores were established by four independent observers. Chromogenic in‐situ hybridization (CISH) was performed on all 2+ cases by manual scoring, DIA or both. HER2 status was considered positive in 3+ and CISH‐positive 2+ cases. Overall agreement between DIA and consensus manual scores was 76.5% (weighted κ = 0.66, BC cut‐offs) and 85.6% (weighted κ = 0.80, GEC cut‐offs). Agreement was similar for biopsies and surgical specimens. All disagreement occurred in the manual IHC equivocal cases. DIA resulted in a reduction of 2+ cases: 75.8% with BC cut‐offs and 46.5% with GEC cut‐offs. HER2 status was positive in 48 cases (15%) with standard diagnostics and DIA using GEC cut‐offs, and 46 cases (14.4%) using BC cut‐offs (all with CISH in 2+ cases). Considering standard diagnostics as a reference, DIA showed 93.8% sensitivity and 99.6% specificity (BC cut‐offs) or 97.9% sensitivity and 99.6% specificity (GEC cut‐offs).ConclusionsDIA is a reliable and feasible alternative to manual HER2 IHC scoring in gastro‐oesophageal adenocarcinoma, both in biopsies and surgical specimens, leading to a reduction of 2+ cases for which subsequent ISH testing is required.
Intratumoral stromal morphometry predicts disease recurrence but not response to 5‐fluorouracil—results from the QUASAR trial of colorectal cancer
Authors: Hutchins Gordon G A , Treanor Darren , Wright Alexander , Handley Kelly , Magill Laura , Tinkler‐Hundal Emma , Southward Katie , Seymour Matthew , Kerr David , Gray Richard , Quirke Philip ,   the QUASAR trial collaborators and the UK National Cancer Research Institute Colorectal Cancer Clinical Studies Group
Published: July 2017

AimsThe biological importance of tumour‐associated stroma is becoming increasingly apparent, but its clinical utility remains ill‐defined. For stage II/Dukes B colorectal cancer (CRC), clinical biomarkers are urgently required to direct therapeutic options. We report here prognostic/predictive analyses, and molecular associations, of stromal morphometric quantification in the Quick and Simple and Reliable (QUASAR) trial of CRC.Methods and resultsRelative proportions of tumour epithelium (PoT) or stroma (PoS) were morphometrically quantified on digitised haematoxylin and eosin (H&E) sections derived from 1800 patients enrolled in QUASAR, which randomised 3239 (91% stage II) CRC patients between adjuvant fluorouracil/folinic acid (FUFA) chemotherapy and observation. The prognostic and predictive values of PoT/PoS measurements were determined by the use of stratified log‐rank analyses. A high proportion of tumour stroma (≥50%) was associated with an increased recurrence risk: 31.3% (143/457) recurrence for ≥50% versus 21.9% (294/1343) for <50% [rate ratio (RR) 1.62; 95% confidence interval (CI) 1.30–2.02; P < 0.0001]. Of patients with stromal proportions of ≥65%, 40% (46/115) had recurrent disease within 10 years. The adverse prognostic effect of a high stromal proportion was independent of established prognostic variables, and was maintained in stage II/Dukes B patients (RR 1.62; 95% CI 1.26–2.08; P = 0.0002). KRAS mutation in the presence of a high stromal proportion augmented recurrence risk (RR 2.93; 95% CI 1.87–4.59; P = 0.0005). Stromal morphometry did not predict response to FUFA chemotherapy.ConclusionsSimple digital morphometry applied to a single representative H&E section identifies CRC patients with a >50% higher risk of disease recurrence. This technique can reliably partition patients into subpopulations with different risks of tumour recurrence in a simple and cost‐effective manner. Further prospective validation is warranted.