bluuebunny/crossref_metadata_2025 huggingface dataset:
Why a Constant Number of Vertebrae? Digital Control of Segmental Identity during Vertebrate Development
Authors: Kudlicki Andrzej
Published: November 2019

It is not understood how the numbers and identities of vertebrae are controlled during mammalian development. The remarkable robustness and conservation of segmental numbers may suggest the digital nature of the underlying process. The study proposes a mechanism that allows cells to obtain and store the segmental information in digital form, and to produce a pattern of chromatin accessibility that in turn regulates Hox gene expression specific to the metameric segment. The model requires that a regulatory element be present such that the number of occurrences of the motif between two consecutive Hox genes equals the number of segments under the control of the anterior gene. This is true for the recently discovered hydroxyl radical cleavage 3bp‐periodic (HRC3) motif, associated with histone modifications and developmental genes. The finding not only allows the correct prediction of the numbers of segments using only sequence information, but also resolves the 40‐year‐old enigma of the function of temporal and spatial collinearity of Hox genes. The logic of the mechanism is illustrated in the attached animated video. How different aspects of the proposed mechanism can be tested experimentally is also discussed.
Associations between blood cultures after surgery for colorectal cancer and long-term oncological outcomes
Authors: Watt S K , Fransgaard T , Degett T H , Thygesen L C , Benfield T , Knudsen J D , Fuursted K , Jensen T G , Dessau R B , Schønheyder H C , Møller J K , Gögenur I
Published: November 2019

Background

Systemic inflammation following curative surgery for colorectal cancer may be associated with increased risk of recurrence. [Correction added on 29 November 2019, after first online publication: text amended for accuracy.] This study investigated whether a clinically suspected infection, for which blood cultures were sent within 30 days after surgery for colorectal cancer, was associated with long-term oncological outcomes.

Methods

This register-based national cohort study included all Danish residents undergoing surgery with curative intent for colorectal cancer between January 2003 and December 2013. Patients who developed recurrence or died within 180 days after surgery were not included. Associations between blood cultures taken within 30 days after primary surgery and overall survival, disease-free survival and recurrence-free survival were analysed using Cox regression models adjusted for relevant clinical confounders, including demographic data, cancer stage, co-morbidity, blood transfusion, postoperative complications and adjuvant chemotherapy.

Results

The study included 21 349 patients, of whom 3390 (15·9 per cent) had blood cultures taken within 30 days after surgery. Median follow-up was 5·6 years. Patients who had blood cultures taken had an increased risk of all-cause mortality (hazard ratio (HR) 1·27, 95 per cent c.i. 1·20 to 1·35; P < 0·001), poorer disease-free survival (HR 1·22, 1·16 to 1·29; P < 0·001) and higher risk of recurrence (HR 1·15, 1·07 to 1·23; P < 0·001) than patients who did not have blood cultures taken.

Conclusion

A clinically suspected infection requiring blood cultures within 30 days of surgery for colorectal cancer was associated with poorer oncological outcomes.
Current trends in isotope‐coded derivatization liquid chromatographic‐mass spectrometric analyses with special emphasis on their biomedical application
Authors: El‐Maghrabey Mahmoud H. , Kishikawa Naoya , Kuroda Naotaka
Published: November 2019

Currently, LC–MS has various applications in different areas such as metabolomics, pharmacokinetics, and pathological studies. Yet, matrix effects resulting from co‐existing constituents remain a major problem for LC–MS [or LC–tandem mass spectrometry (LC–MS/MS)]. Moreover, technical problems and instrumental drifts may lead to ion abundance variance. Thus, an internal standard (IS) is required to guarantee the accuracy and precision of the method. Because of their limited number, isotope‐coded derivatization (ICD) has been recently introduced to overcome this problem. For ICD, a stable heavy isotope‐coded moiety is used for labeling the standard or the control sample and the formed products can act as ISs. A light form of the reagent is used for labeling the sample. Then, both are mixed and analyzed by LC–MS(/MS). This strategy permits the identification of different unknown analytes including potential metabolites and disease biomarkers. All these attributes lead to persistent growth in the applications of ICD LC–MS(/MS) in various biomedical branches. In this article we review the ICD methods published in the last eight years for biomedical applications as well as briefly summarize other applications for environmental and food analyses as some of their used ICD reagents were further applied for analyzing biological specimens or have the potential for that.
SH‐SY5Y and LUHMES cells display differential sensitivity to MPP+, tunicamycin, and epoxomicin in 2D and 3D cell culture
Authors: Ko Kristin Robin , Tam Nicky W. , Teixeira Alyne G. , Frampton John P.
Published: November 2019

SH‐SY5Y and LUHMES cell lines are widely used as model systems for studying neurotoxicity. Most of the existing data regarding the sensitivity of these cell lines to neurotoxicants have been recorded from cells growing as two‐dimensional (2D) cultures on the surface of glass or plastic. With the emergence of 3D culture platforms designed to better represent native tissue, there is a growing need to compare the toxicology of neurons grown in 3D environments to those grown in 2D to better understand the impact that culture environment has on toxicant sensitivity. Here, a simple 3D culture method was used to assess the impact of growth environment on the sensitivity of SH‐SY5Y cells and LUHMES cells to MPP+, tunicamycin, and epoxomicin, three neurotoxicants that have been previously used to generate experimental models for studying Parkinson's disease pathogenesis. SH‐SY5Y cell viability following treatment with these three toxicants was significantly lower in 2D cultures as compared to 3D cultures. On the contrary, LUHMES cells did not show significant differences between growth conditions for any of the toxicants examined. However, LUHMES cells were more sensitive to MPP+, tunicamycin, and epoxomicin than SH‐SY5Y cells. Thus, both the choice of cell line and the choice of growth environment must be considered when interpreting in vitro neurotoxicity data.
Best practices for alcohol education on campus
Authors: Rahn Josh
Published: November 2019

Alcohol abuse, and the collateral damage it often causes, is a continuous health and safety challenge on most college campuses. Mitigating alcohol‐related issues requires a comprehensive set of evidence‐based tools and strategies. These strategies often include programs that begin before students attend their first classes.
Student mental health: The ongoing crisis
Authors: Zacarese Lawrence M.
Published: November 2019

It is no secret that the country has its hands full dealing with mental health awareness, identification, and treatment — all while facing a lack of resources. Law enforcement and public safety organizations throughout the nation are faced with similar dilemmas in that they all seem to struggle with resources. Lack of personnel, training, effective use of technology, and practical experience are just a few of the challenges we all face.
Decreasing sexual assault on campus is a communitywide endeavor
Authors: Sutton Halley
Published: November 2019

Christi Hurt experienced a baptism by fire when she joined the campus safety team at the University of North Carolina, Chapel Hill as the first full‐time Title IX Coordinator for the campus. Hurt, now the Vice President for Strategic Initiatives at Margolis Healy and Associates and Cozen O'Connor's Institutional Response Group, said one of her first assignments as the Title IX Coordinator was to chair the campuswide Sexual Assault Task Force to come up with new university policies prohibiting sexual misconduct. “It was the greatest experience of my professional career,” Hurt said.
Sheathless guiding catheter from a femoral approach for complex percutaneous coronary interventions —An unusual solution for an often‐encountered problem
Authors: Israeli Zeev , Nordkin Irina , Goldberg Alexander , Halabi Majdi
Published: November 2019

Sheathless guiding catheters are a valuable tool in the catheterization labor and may assist the operator when dealing with heavily calcified and tortuous vessels. Nevertheless, when hostile anatomy prevents successful percutaneous coronary interventions (PCI) from the radial access, transfemoral use of sheathless guide can assist in overcoming these challenges in a safe manner.
Ultrasensitive Detection of ctDNA by Target‐Mediated In Situ Growth of DNA Three‐Way Junction on the Electrode
Authors: Chen Xifeng , Tang Yuguo , Yan Ruhong , Miao Peng
Published: November 2019

Circulation tumor DNA (ctDNA) is an emerging biomarker for diagnosis and therapy of cancers. Herein, an ultrasensitive electrochemical method for ctDNA quantification is developed by in situ growth of DNA three‐way junction on the electrode. Three hairpin‐structured DNA probes are used as fuel strands and strand‐displacement polymerization reactions are initiated by target ctDNA for the in situ growth of the DNA junction structure, which changes the electron transfer pathways of electrochemical species. By further employing a reductant‐mediated amplification, the method shows sub‐femtomolar sensitivity. Meanwhile, specific analysis of ctDNA is achieved with negligible interference by DNAs with one or more mismatched sites. Therefore, the proposed method may have great analytical and clinical applications.
Versatile Bispidine‐Based Bifunctional Chelators for 64CuII‐Labelling of Biomolecules
Authors: Singh Garima , Zarschler Kristof , Hunoldt Sebastian , Martínez Irma Ivette Santana , Ruehl Carmen L. , Matterna Madlen , Bergmann Ralf , Máthé Domokos , Hegedüs Nikolett , Bachmann Michael , Comba Peter , Stephan Holger
Published: November 2019

Bifunctional chelators as parts of modular metal‐based radiopharmaceuticals are responsible for stable complexation of the radiometal ion and for covalent linkage between the complex and the targeting vector. To avoid loss of complex stability, the bioconjugation strategy should not interfere with the radiometal chelation by occupying coordinating groups. The C9 position of the very stable CuII chelator 3,7‐diazabicyclo[3.3.1]nonane (bispidine) is virtually predestined to introduce functional groups for facile bioconjugation as this functionalisation does not disturb the metal binding centre. We describe the preparation and characterisation of a set of novel bispidine derivatives equipped with suitable functional groups for diverse bioconjugation reactions, including common amine coupling strategies (bispidine‐isothiocyanate) and the Cu‐free strain‐promoted alkyne–azide cycloaddition. We demonstrate their functionality and versatility in an exemplary way by conjugation to an antibody‐based biomolecule and validate the obtained conjugate in vitro and in vivo.
Pseudo‐Gated Adsorption with Negligible Volume Change Evoked by Halogen‐Bond Interaction in the Nanospace of MOFs
Authors: Kanoo Prakash , Matsuda Ryotaro , Sato Hiroshi , Li Liangchun , Hosono Nobuhiko , Kitagawa Susumu
Published: November 2019

The enhancement of gas adsorption utilizing weak interactions in porous compounds is highly demanding for the design of energy‐efficient storage materials. Here, we present a rational design for such an adsorption process by using synergistic functions between dynamic motion in a local module and weak but specific host–guest interactions, that is, halogen‐bond (XB) interactions in metal–organic frameworks (MOFs). We designed a new porous coordination polymer (PCP), that is, Br‐PCP, the pore surfaces of which are decorated with −CH2Br groups and could be useful for interaction with CO2 molecules. In accordance with our anticipation, in‐situ studies suggest that the adsorption step at approximately 54 kPa during CO2 adsorption is indeed facilitated by XB interactions with little change in the structural volume. This approach of integrating flexible XB modules in rigid PCPs is applicable for designing advanced gas storage systems.
Identification of Phenylphthalazinones as a New Class of Leishmania infantum Inhibitors
Authors: Sijm Maarten , de Heuvel Erik , Matheeussen An , Caljon Guy , Maes Louis , Sterk Geert‐Jan , de Esch Iwan J. P. , Leurs Rob
Published: November 2019

Leishmaniasis is a neglected parasitic disease caused by over 20 different Leishmania species. Current treatments often rely on harsh regimes of pentavalent antimonials such as sodium stibogluconate, while more recent drugs suffer other shortcomings such as low stability and rapid emergence of treatment failure, amongst others. Furthermore, the effectiveness of drugs varies depending on the infecting Leishmania species, thus there is an urgent need for new and effective anti‐leishmanial drugs. Screening of an in‐house compound library identified the hexahydrophthalazinone NPD‐2942 as a low micromolar hit with a pIC50 of 5.8 against L. infantum and a pIC50 of 4.6 for cytotoxicity against human MRC‐5 fibroblasts. To derive structure–activity relationships, we modified the cyclohexyl ring of the hexahydrophthalazinone scaffold and 1,2,3‐triazoles were attempted as replacement for the pyrazole ring, amongst others. Ultimately, the 2,3‐pyrazole‐substituted hexahydrophthalazinone NPD‐1289 was identified as the most potent analogue in this series with a pIC50 of 6.3, although some cytotoxicity toward MRC‐5 cells (pIC50=5.1) was recorded as well. Replacement of the unsubstituted 2,3‐pyrazole with 1,2,3‐triazoles led to compounds with lower anti‐leishmanial activity. The current scaffold is a valuable new starting point for optimization toward novel anti‐leishmanial drugs.
Structure–Function Studies on IMD‐0354 Identifies Highly Active Colistin Adjuvants
Authors: Nemeth Ansley M. , Basak Akash K. , Weig Alexander W. , Marrujo Santiana A. , Barker William T. , Jania Leigh A. , Hendricks Tyler A. , Sullivan Ashley E. , O'Connor Patrick M. , Melander Roberta J. , Koller Beverly H. , Melander Christian
Published: November 2019

Infections caused by multidrug‐resistant (MDR) bacteria, particularly Gram‐negative bacteria, are an escalating global health threat. Often clinicians are forced to administer the last‐resort antibiotic colistin; however, colistin resistance is becoming increasingly prevalent, giving rise to the potential for a situation in which there are no treatment options for MDR Gram‐negative infections. The development of adjuvants that circumvent bacterial resistance mechanisms is a promising orthogonal approach to the development of new antibiotics. We recently disclosed that the known IKK‐β inhibitor IMD‐0354 potently suppresses colistin resistance in several Gram‐negative strains. In this study, we explore the structure–activity relationship (SAR) between the IMD‐0354 scaffold and colistin resistance suppression, and identify several compounds with more potent activity than the parent against highly colistin‐resistant strains of Acinetobacter baumannii and Klebsiella pneumoniae.
Plasma‐thrombin cell blocks: Potential source of DNA contamination
Authors: Sung Simon , Sireci Anthony N. , Remotti Helen E. , Hodel Vaishali , Mansukani Mahesh M. , Fernandes Helen , Saqi Anjali
Published: November 2019

Background

Cell blocks are being used more frequently in cytology for ancillary testing, including molecular diagnostics. There are several different methods of processing cell blocks, with plasma‐thrombin being one of the most common. Plasma is a blood‐derived product and may be a source of DNA. The aim of this study was to determine whether the plasma used for the plasma‐thrombin cell block method has amplifiable DNA that may potentially interfere with molecular testing results.

Methods

Expired bags of fresh frozen plasma were collected from a blood bank. From each sample, DNA was extracted from a 1‐mL aliquot with the QIAsymphony MIDI kit (Qiagen). The concentration of DNA was measured on a NanoDrop instrument. The amplifiable DNA quality was assessed by polymerase chain reaction (PCR) with primers to generate amplicons of various sizes. Characterization was performed with the AmpFLSTR Identifiler Plus PCR kit with capillary electrophoresis.

Results

Twenty samples from 20 bags were collected. All samples showed amplifiable DNA despite low DNA concentrations in a few cases. PCR amplification revealed the presence of high‐quality amplifiable DNA (up to 600 base pairs). DNA was amplified at the 16 loci interrogated in all samples tested with the AmpFLSTR Identifiler Plus PCR kit.

Conclusions

The presence of genomic DNA in plasma may theoretically interfere with results of molecular testing. Particularly in clinical samples with low cellularity, the DNA in plasma may potentially either mask the presence of minute amounts of tumor‐derived DNA or lead to a false‐positive result.
Plasmon‐Enhanced Photoluminescence and Photocatalysis Reactions in Metal‐Semiconductor Nanomaterials: UV‐Generated Hot Electron in Gold‐Zinc Oxide
Authors: Shahine Issraa , Jradi Safi , Beydoun Nour , Gaumet Jean‐Jacques , Akil Suzanna
Published: November 2019

Herein, we introduce a mechanistic study to design a hybrid junction in metallic‐semiconductor (M/SC) nanostructures. UV‐light‐induced hot electron generation in ZnO nanostructures is used to precisely tune the photoluminescence (PL) and photocatalytic (PC) properties in hybrid Au/ZnO nanomaterials. Both enhancement and quenching of the PL and PC functionalities are observed, depending on the properties of the Au nanoparticles (AuNPs) and the Au/ZnO molecular distance. Under UV irradiation free‐ligand AuNPs quench the luminescence of ZnONPs through direct charge transfer (CT) from ZnO to the AuNPs. In contrast, capped AuNPs enhance the ZnO emission through indirect CT from AuNPs to ZnONPs facilitated by the distance created by the CTAB ligand between both constituents of the hybrid systems. It is necessary to optimise the Au/ZnO molecular distance to achieve an enhancement of both the plasmonic photocatalysis reaction and photoelectric properties of M/SC nanostructures. This phenomena is mediated by the energy transfer (ET) from ZnONPs to AuNPs. The resulting PL enhancement is described by the plasmon‐induced resonance energy transfer effect (PIRET effect).
The relationship between emissions reduction and financial performance: Are Portuguese companies in a sustainable development path?
Authors: Robaina Margarita , Madaleno Mara
Published: November 2019

Companies are increasingly adopting strategies that simultaneously reduce their negative impact on the environment and minimize the extraction of natural and energy resources, used as inputs in their production process. The concern for the sustainable development of countries and regions and environmental sustainability of companies is increasingly present. Nevertheless, does it make up for the increased costs to protect the environment? The objective of this study is to evaluate how the environmental performance (EP) and the financial performance (FP) of companies are related, applying to the specific case of Portuguese companies during the 2008–2016 period. The relationship between pollution and FP reveals to be positive. Still, firms regard EP as additional costs, and these efforts do not seem to be strong enough to lead to a better FP. Both munificence and resource slack are included and reveal to have positive effects over FP and in the EP–FP relationship.

Highlights

Pollution and financial performance relationship is positive (negative EP‐FP link).

Environmental performance are additional costs; firms favor financial performance.

Munificence and slack have positive effects over financial performance.

Munificent environments provide an opportunity for environmental investments.

Scarce slack resources: less willingness to undertake social‐responsible actions.
Laser Fragmentation‐Induced Defect‐Rich Cobalt Oxide Nanoparticles for Electrochemical Oxygen Evolution Reaction
Authors: Yu Mingquan , Waag Friedrich , Chan Candace K. , Weidenthaler Claudia , Barcikowski Stephan , Tüysüz Harun
Published: November 2019

Sub‐5 nm cobalt oxide nanoparticles are produced in a flowing water system by pulsed laser fragmentation in liquid (PLFL). Particle fragmentation from 8 nm to 4 nm occurs and is attributed to the oxidation process in water where oxidative species are present and the local temperature is rapidly elevated under laser irradiation. Significantly higher surface area, crystal phase transformation, and formation of structural defects (Co2+ defects and oxygen vacancies) through the PLFL process are evidenced by detailed structural characterizations by nitrogen physisorption, electron microscopy, synchrotron X‐ray diffraction, and X‐ray photoelectron spectroscopy. When employed as electrocatalysts for the oxygen evolution reaction under alkaline conditions, the fragmented cobalt oxides exhibit superior catalytic activity over pristine and nanocast cobalt oxides, delivering a current density of 10 mA cm−2 at 369 mV and a Tafel slope of 46 mV dec−1, which is attributed to a larger exposed active surface area, the formation of defects, and an increased charge transfer rate. The study provides an effective approach to engineering cobalt oxide nanostructures in a flowing water system, which shows great potential for sustainable production of active cobalt catalysts.
Mental health issues on campus require consideration of legal issues, risks
Authors: Porter Michael
Published: November 2019

Fostering individual social and emotional growth is critical to the work of institutions of higher education. New students find themselves in challenging and unfamiliar environments when they arrive on campus and participate in a school's educational and social activities. And beyond new students, within each campus community are people dealing with the gamut of human experiences. Individual mental health issues, then, frequently present themselves to administrators, faculty, counselors, or other staff. Regardless of whether an institution is broadly open to the community, such as a community college, or a highly selective institution, for some, the pressures, environment, and physiological factors bear on mental health. As colleges and universities address students’ emotional health, they should be aware of the legal framework for addressing individuals with mental health needs and potential risks associated with acts institutions take or fail to take.
Large‐scale tactile map becomes valued aid for sight‐impaired
Authors: Enos Gary
Published: November 2019

Few colleges have a tactile three‐dimensional map to assist sight‐impaired students in navigating a challenging campus layout. The functional map unveiled last May at Portland State University is noteworthy for its scale and detail, and has become a valued resource throughout the university community. Michael Cantino, an accessibility specialist at nearby Portland Community College, described the effort's objectives and the role student feedback played in shaping the design.
Leaves of absence in health science programs: Not a catch‐all solution
Authors: Meeks Lisa M. , Murray Joseph F.
Published: November 2019

Health science students with disabilities may experience a worsening of symptoms that can fluctuate and impact their functioning. A myopic response to these flares is to suggest a leave of absence. In these cases, the message to the student is “Take some time off and get this fixed. Then return when you are well.” The flaw in this approach is the idea that students must be 100% well to engage in the program. Functioning occurs on a spectrum from low functioning (where a student may legitimately require a leave) to high functioning (where no limitations exist). Many students experiencing a flare fall in the middle, able to continue in the program with the aid of accommodations (see “Mental health and functioning” box at bottom of page).
Department of Education issues guidance on disability funds allocation
Authors: Sutton Halley
Published: November 2019

The United States Department of Education has issued guidance for better overseeing how students with disabilities are incorporated into postsecondary education, via a question‐and‐answer document. The document “describes how State educational agencies (SEAs), local educational agencies (LEAs), and State vocational rehabilitation (VR) agencies may coordinate to assist students and youth with disabilities,” along with resources to help educational institutions support students with disabilities. The guide was issued specifically to combat confusion about allocation of funds that recently forced students with disabilities to withdraw from or forgo attending institutions of higher education.
Estimating correlations among demographic parameters in population models
Authors: Riecke Thomas V. , Sedinger Benjamin S. , Williams Perry J. , Leach Alan G. , Sedinger James S.
Published: November 2019

Estimating correlations among demographic parameters is critical to understanding population dynamics and life‐history evolution, where correlations among parameters can inform our understanding of life‐history trade‐offs, result in effective applied conservation actions, and shed light on evolutionary ecology. The most common approaches rely on the multivariate normal distribution, and its conjugate inverse Wishart prior distribution. However, the inverse Wishart prior for the covariance matrix of multivariate normal distributions has a strong influence on posterior distributions. As an alternative to the inverse Wishart distribution, we individually parameterize the covariance matrix of a multivariate normal distribution to accurately estimate variances (σ2) of, and process correlations (ρ) between, demographic parameters. We evaluate this approach using simulated capture–mark–recapture data. We then use this method to examine process correlations between adult and juvenile survival of black brent geese marked on the Yukon–Kuskokwim River Delta, Alaska (1988–2014). Our parameterization consistently outperformed the conjugate inverse Wishart prior for simulated data, where the means of posterior distributions estimated using an inverse Wishart prior were substantially different from the values used to simulate the data. Brent adult and juvenile annual apparent survival rates were strongly positively correlated (ρ = 0.563, 95% CRI 0.181–0.823), suggesting that habitat conditions have significant effects on both adult and juvenile survival. We provide robust simulation tools, and our methods can readily be expanded for use in other capture–recapture or capture‐recovery frameworks. Further, our work reveals limits on the utility of these approaches when study duration or sample sizes are small.
Variation in community structure of gall‐inducing insects associated with a tropical plant supports the hypothesis of competition in stressful habitats
Authors: Ramos Letícia F. , Solar Ricardo R. C. , Santos Henrique T. , Fagundes Marcilio
Published: November 2019

Environmental factors act as drivers of species coexistence or competition. Mesic environments favor the action of parasites and predators on gall communities, while the factors that determine the structure of gall communities in xeric environments remain unknown. We evaluated the structure of gall communities along an environmental gradient defined by intrinsic plant characteristics, soil fertility, and aridity, and investigated the role of competition as a structuring force of gall communities in xeric environments. We created null models to compare observed and simulated patterns of co‐occurrence of galls and used the C‐score index to assess community aggregation or segregation. We used the NES C‐score (standardized C‐score) to compare patterns of co‐occurrence with parameters of environmental quality. Xeric environments had poorer and more arid soils and more sclerophyllous plants than mesic environments, which was reflected in the distribution patterns of gall communities. Values of the C‐score index revealed a segregated distribution of gall morphospecies in xeric environments, but a random distribution in mesic environments. The low availability of resources for oviposition and the high density of gallers in xeric environments reinforce interspecific competition as an important structuring force for gall communities in these environments.
Accumulating evidence in ecology: Once is not enough
Authors: Nichols James D. , Kendall William L. , Boomer Gregory Scott
Published: November 2019

Many published studies in ecological science are viewed as stand‐alone investigations that purport to provide new insights into how ecological systems behave based on single analyses. But it is rare for results of single studies to provide definitive results, as evidenced in current discussions of the “reproducibility crisis” in science. The key step in science is the comparison of hypothesis‐based predictions with observations, where the predictions are typically generated by hypothesis‐specific models. Repeating this step allows us to gain confidence in the predictive ability of a model, and its corresponding hypothesis, and thus to accumulate evidence and eventually knowledge. This accumulation may occur via an ad hoc approach, via meta‐analyses, or via a more systematic approach based on the anticipated evolution of an information state. We argue the merits of this latter approach, provide an example, and discuss implications for designing sequences of studies focused on a particular question. We conclude by discussing current data collection programs that are preadapted to use this approach and argue that expanded use would increase the rate of learning in ecology, as well as our confidence in what is learned.
Density‐dependent space use affects interpretation of camera trap detection rates
Authors: Broadley Kate , Burton A. Cole , Avgar Tal , Boutin Stan
Published: November 2019

Camera traps (CTs) are an increasingly popular tool for wildlife survey and monitoring. Estimating relative abundance in unmarked species is often done using detection rate as an index of relative abundance, which assumes that detection rate has a positive linear relationship with true abundance. This assumption may be violated if movement behavior varies with density, but the degree to which movement behavior is density‐dependent across taxa is unclear. The potential confounding of population‐level relative abundance indices by movement would depend on how regularly, and by what magnitude, movement rate and home‐range size vary with density. We conducted a systematic review and meta‐analysis to quantify relationships between movement rate, home‐range size, and density, across terrestrial mammalian taxa. We then simulated animal movements and CT sampling to test the effect of contrasting movement scenarios on CT detection rate indices. Overall, movement rate and home‐range size were negatively correlated with density and positively correlated with one another. The strength of the relationships varied significantly between taxa and populations. In simulations, detection rates were related to true abundance but underestimated change, particularly for slower moving species with small home ranges. In situations where animal space use changes markedly with density, we estimate that up to thirty percent of a true change in relative abundance may be missed due to the confounding effect of movement, making trend estimation more difficult. The common assumption that movement remains constant across densities is therefore violated across a wide range of mammal species. When studying unmarked species using CT detection rates, researchers and managers should explicitly consider that such indices of relative abundance reflect both density and movement. Practitioners interpreting changes in camera detection rates should be aware that observed differences may be biased low relative to true changes in abundance. Further information on animal movement, or methods that do not depend on assumptions of density‐independent movement, may be required to make robust inferences on population trends.
Population genetic structure and adaptive differentiation of iron walnut Juglans regia subsp. sigillata in southwestern China
Authors: Sun Yi‐Wei , Hou Na , Woeste Keith , Zhang Chuchu , Yue Ming , Yuan Xiao‐Ying , Zhao Peng
Published: November 2019

Southwestern (SW) China is an area of active tectonism and erosion, yielding a dynamic, deeply eroded landscape that influences the genetic structure of the resident populations of plants and animals. Iron walnut (Juglans regia subsp. sigillata) is a deciduous tree species endemic to this region of China and cultivated there for its edible nuts. We sampled 36 iron walnut populations from locations throughout the species' range in SW China and genotyped a total of 765 individuals at five chloroplast DNA regions and 22 nuclear microsatellite loci. Species distribution models were produced to predict the evolution and historical biogeography of iron walnut and to estimate the impacts of climate oscillations and orographic environments on the species' demography. Our results indicated that J. regia subsp. sigillata had relatively low genetic diversity, high interpopulation genetic differentiation, and asymmetric interpopulation gene flow. Based on DIYABC analysis, we identified two lineages of J. sigillata in southwestern China. The lineages (subpopulations) diverge during the last glacial period (~1.34 Ma). Southwestern China was a glacial refuge during the last glacial period, but increasingly colder and arid climates might have fostered the fragmentation of J. regia subsp. sigillata within this refugium. Finally, we found that recent habitat fragmentation has led to a reduction in population connectivity and increased genetic differentiation by genetic drift in isolated populations. Our results support a conclusion that geological and climatic factors since the Miocene triggered the differentiation, evolutionary origin, and range shifts of J. sigillata in the studied region.
Links between prey assemblages and poison frog toxins: A landscape ecology approach to assess how biotic interactions affect species phenotypes
Authors: Prates Ivan , Paz Andrea , Brown Jason L. , Carnaval Ana C.
Published: November 2019

Ecological studies of species pairs showed that biotic interactions promote phenotypic change and eco‐evolutionary feedbacks. However, it is unclear how phenotypes respond to synergistic interactions with multiple taxa. We investigate whether interactions with multiple prey species explain spatially structured variation in the skin toxins of the neotropical poison frog Oophaga pumilio. Specifically, we assess how dissimilarity (i.e., beta diversity) of alkaloid‐bearing arthropod prey assemblages (68 ant species) and evolutionary divergence between frog populations (from a neutral genetic marker) contribute to frog poison dissimilarity (toxin profiles composed of 230 different lipophilic alkaloids sampled from 934 frogs at 46 sites). We find that models that incorporate spatial turnover in the composition of ant assemblages explain part of the frog alkaloid variation, and we infer unique alkaloid combinations across the range of O. pumilio. Moreover, we find that alkaloid variation increases weakly with the evolutionary divergence between frog populations. Our results pose two hypotheses: First, the distribution of only a few prey species may explain most of the geographic variation in poison frog alkaloids; second, different codistributed prey species may be redundant alkaloid sources. The analytical framework proposed here can be extended to other multitrophic systems, coevolutionary mosaics, microbial assemblages, and ecosystem services.
A global‐scale analysis of water storage dynamics of inland wetlands: Quantifying the impacts of human water use and man‐made reservoirs as well as the unavoidable and avoidable impacts of climate change
Authors: Döll Petra , Trautmann Tim , Göllner Mareike , Schmied Hannes Müller
Published: November 2019

Wetlands such as bogs, swamps, or freshwater marshes are hotspots of biodiversity. For 5.1 million km2 of inland wetlands, the dynamics of area and water storage, which strongly impact biodiversity and ecosystem services, were simulated using the global hydrological model WaterGAP. For the first time, the impacts of both human water use and man‐made reservoirs (WUR) and future climate change (CC) on wetlands around the globe were quantified. WUR impacts are concentrated in arid/semiarid regions, where WUR decreased mean wetland water storage by more than 5% on 8.2% of the mean wetland area during 1986–2005 (Am), with highest decreases in groundwater depletion area. Using output of three climate models, CC impacts on wetlands were quantified, distinguishing unavoidable impacts [i.e., at 2 °C global warming (GW)] from avoidable impacts (difference between 3 °C and 2 °C impacts). Even unavoidable CC impacts are projected to be much larger than WUR impacts, also in arid/semiarid regions. On most wetland area with reliable estimates, avoidable CC impacts are more than twice as large as unavoidable impacts. In case of 2 °C GW, half of Am is estimated to be unaffected by mean storage changes of more than 5%, but only one third in case of 3 °C GW. Temporal variability of water storage will increase for most wetlands. Wetlands in dry regions will be affected the most, particularly by water storage decreases in the dry season. Different from wealthier countries, low‐income countries will dominantly suffer from a decrease in wetland water storage due to CC.
Analysis of air/river maximum daily temperature characteristics using the peaks over threshold approach
Authors: Caissie Daniel , Ashkar Fahim , El‐Jabi Nassir
Published: November 2019

The understanding of river temperature is very important when assessing fish habitat conditions in terms of fish growth as well as fish distribution within river systems. The quantification of extreme water temperatures is also important, especially when studying the suitability of thermal habitats during high air/water temperature events. The present study deals with the analysis of extreme air and water temperatures using the partial duration series approach, also known as the peak over threshold (POT) approach. The advantage of the POT approach is that extreme air and water temperatures can be described not only in magnitude but also in duration and degree day accumulation for each event. In the present study, 74 years of air temperature data (Miramichi meteorological station) were analysed as well as 21 years of river temperature data from the Little Southwest Miramichi River. For example, results showed that the 0.01 exceedance probability (F(x) = .99) for maximum daily air temperature event was calculated at 38.4°C whereas for the same exceedance probability, the maximum daily water temperature event was slightly lower at 32.7°C. The duration of events varied between 1 and 5 days for air temperature and between 1 and 7 days for water temperature. Maximum daily water temperature exceeding 30°C generally occurred over a period of 3 days or more, and the degree day accumulation was higher than 6°C·day. This study showed that the POT approach was effective in quantifying both air and water temperature extremes within the Miramichi River study area.
Long‐term effects of land‐use change on bird communities depend on spatial scale and land‐use type
Authors: Allen Daniel C. , Bateman Heather L. , Warren Paige S. , de Albuquerque Fabio Suzart , Arnett‐Romero Sky , Harding Bridget
Published: November 2019

Land‐use transformation is one of the most important and pervasive ecological changes occurring across the Earth, but its long‐term effects are poorly understood. Here, we analyze the effects of urban and agriculture development on bird biodiversity and community structure over a 16‐yr study period. We found that long‐term effects of land‐use change are dependent on spatial scale and land‐use type. At the regional scale, we found that gamma diversity (total number of species observed) declined by ~10% over time. At the landscape spatial scale, we found that beta diversity (uniqueness of bird communities) increased by ~16% over time. Additionally, the average contributions of urban riparian bird communities to beta diversity were generally the highest but declined by ~26% over the study period. Contributions of urban communities to beta diversity were generally the lowest but increased by ~10% over time. At the local scale, we observed different responses for different measures of alpha diversity. For bird species richness, temporal changes varied by land use. Species richness declined 16% at sites in desert riparian areas but increased by 21% and 12% at sites in urban and agricultural areas, respectively. Species evenness declined across all land uses, with some land uses experiencing more rapid declines than others. Our analysis of species groups that shared certain traits suggests that these community‐level changes were driven by species that are small, breed onsite, and feed on insects, grains, and nectar. Collectively, our results suggest that biodiversity declines associated with land‐use change predominate at the regional and local spatial scale, and that these effects can strengthen or weaken over time. However, these changes counterintuitively led to increases in biodiversity at the landscape scale, as bird communities became more unique. This has implications for conservation and management as it shows that the effects of land‐use modification on biodiversity may be positive or negative depending on the spatial scale considered.
Ecological consequences of compound disturbances in forest ecosystems: a systematic review
Authors: Kleinman J. S. , Goode J. D. , Fries A. C. , Hart J. L.
Published: November 2019

Investigations of compound disturbances that alter forest resilience (i.e., recovery time or trajectory) have escalated over the past two decades. We used a systematic approach to identify and describe the ecological consequences of discrete forest disturbance events involved in compound interactions. Fire, wind disturbance, and salvage logging were the most common disturbance types investigated. Most compound interactions occurred in North America and involved five or fewer years between disturbances. Common and interrelated disturbance legacies that facilitated compound interactions included reduced seed source availability, deadwood deposition and extraction, and increased light and growing space availability. Forest recovery was assessed with a diversity of metrics including woody and herbaceous plants, soil properties, and carbon stocks, which sometimes determined whether and what kind of compound interaction was detected. Distinctions between recovery time and trajectory, forest succession and development, and species‐specific and community‐level responses also influenced the detection and direction of compound interactions. Moving forward, we advocate a more holistic approach to quantify ecosystem recovery that considers multiple response variables. Other opportunities to improve compound disturbance ecology include increased emphasis on understudied disturbance types, regions, and forest types. We also encourage more research on buffering interactions that increase forest resilience, which were underrepresented in this review.
Recent Advances in the Catalytic Asymmetric Synthesis of β2‐ and β2,2‐Amino Acids
Authors: Noda Hidetoshi , Shibasaki Masakatsu
Published: November 2019

The importance of β‐amino acids for peptidomimetics and their presence in numerous natural products and pharmaceuticals make the development of the corresponding synthetic procedures a task of high practical significance. Herein, we focus on the recent developments in the catalytic asymmetric synthesis of β2‐ and β2,2‐amino acids. The examples are arranged according to strategic bond disconnections. Despite the abundance of feasible approaches, only a handful of reaction types can effectively furnish β2‐ and β2,2‐amino acid derivatives with sufficient enantioselectivity suitable for peptide applications. These include asymmetric hydrogenation or conjugate addition of acrylates, α‐functionalization of β‐amino acid enolate precursors, and aminomethylation of carbonyl compounds. Hence, future research directions are discussed considering these literature precedents.
Energy and Environmental Contributions for Future Natural Gas Supply Planning in Brazil
Authors: Sakamoto Hugo , Maciel Michelli , Henrique Cardoso Fernando , Kulay Luiz
Published: November 2019

Natural gas has become a strategic source of energy, despite its technical and economic benefits, largely due to its lower environmental impacts compared with other fuels. Given this scenario, Brazil has increased the availability of this resource to meet the demand of more interior regions and increases its autonomy with respect to this fuel. The aim of this study is to evaluate the environmental impacts of current and future natural gas supply situations in Brazil. To this end, the life cycle assessment (LCA) technique is applied, with a cradle‐to‐gate approach for the climate change (CC) and primary energy demand (PED) impact categories. For the current scenario, the main contributions to CC occur in the form of CH4 emissions during gas transportation operations (crude or refined) and resource withdrawal from reserves. For future supplies, the applied analysis identifies transport distance as an important PED focus, whereas the same parameter and the distributed volume of refined gas are noteworthy as impact sources concerning CC.
Using terrestrial LiDAR to measure water erosion on stony plots under simulated rainfall
Authors: Li Li , Nearing Mark A. , Nichols Mary H. , Polyakov Viktor O. , Cavanaugh Michelle L.
Published: November 2019

Terrestrial LiDAR scanning (TLS) technology is widely used to detect terrain elevation changes. This study examines the potential use of terrestrial LiDAR to measure erosion on small experimental plots at high resolution. Multitemporal TLS scans were conducted at six positions around plots (12 m2) with three slope treatments through 11 simulated rainfall applications. Surface elevation changes were quantified by comparing scans between rainfall simulations, and elevation changes greater than the level of detection were used to obtain volumetric change estimations. Erosion mass was estimated both by using soil bulk density and the density of sediment collected in runoff, and then compared to the erosion estimated from the runoff samples. Results showed: (1) with the aid of fixed reference controls in the form of concrete target surfaces of varying roughness, registration accuracy was better than 1 mm and mean level of change detection was less than 2.2 mm; (2) the average absolute relative errors of TLS‐estimated eroded mass ranged from 6.8% to 31.8%, with greater values on 5% slope; (3) the TLS‐estimated erosion accuracy was affected by erosion magnitude, the utilized material density and number of scan positions, and a grid size of 10 mm was found to be appropriate for this scale to estimate the volumetric changes; (4) the number of scan positions could be reduced to three while not significantly impacting volumetric change estimations; and (5) elevating the scanner resulted in much better accuracy for eroded mass estimations. This study suggests that using LiDAR to monitor soil erosion at the plot scale is feasible, and provides guidance about the level of accuracy one might expect in doing so. © 2019 John Wiley & Sons, Ltd.