bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluierung der Reaktionsbedingungs‐basierten Sensitivität chemischer Transformationen
Authors: Pitzer Lena , Schäfers Felix , Glorius Frank
Published: April 2019

Eine systematische, nutzerfreundliche Evaluierungsmethode, die einen klaren Überblick über die Empfindlichkeit chemischer Transformationen in Bezug auf Reaktionsparameter liefert, ist höchst wünschenswert. Im Folgenden wird die Entwicklung einer solchen Methode beschrieben. Dabei ermöglicht die intuitive, standardisierte Darstellung der Ergebnisse mittels eines Radardiagramms eine schnelle Beurteilung der Sensitivität eines Protokolls. Die entwickelte Methode wird anhand fünf verschiedener photochemischer Reaktionen demonstriert und die Ergebnisse werden mit dem jeweils zugrunde liegenden Mechanismus korreliert. Die Anwendung der hier vorgestellten Evaluierung könnte dazu beitragen, die Reproduzierbarkeit und damit auch die breitere Akzeptanz neuer Synthesemethoden zu steigern.
Formation and Functioning of Bimetallic Nanocatalysts: The Power of X‐ray Probes
Authors: Filez Matthias , Redekop Evgeniy A. , Dendooven Jolien , Ramachandran Ranjith K. , Solano Eduardo , Olsbye Unni , Weckhuysen Bert M. , Galvita Vladimir V. , Poelman Hilde , Detavernier Christophe , Marin Guy B.
Published: April 2019

Bimetallic nanocatalysts are key enablers of current chemical technologies, including car exhaust converters and fuel cells, and play a crucial role in industry to promote a wide range of chemical reactions. However, owing to significant characterization challenges, insights in the dynamic phenomena that shape and change the working state of the catalyst await further refinement. Herein, we discuss the atomic‐scale processes leading to mono‐ and bimetallic nanoparticle formation and highlight the dynamics and kinetics of lifetime changes in bimetallic catalysts with showcase examples for Pt‐based systems. We discuss how in situ and operando X‐ray spectroscopy, scattering, and diffraction can be used as a complementary toolbox to interrogate the working principles of today's and tomorrow's bimetallic nanocatalysts.
Bacteria‐Based Production of Thiol‐Clickable, Genetically Encoded Lipid Nanovesicles
Authors: Royes Jorge , Ilioaia Oana , Lubart Quentin , Angius Federica , Dubacheva Galina V. , Bally Marta , Miroux Bruno , Tribet Christophe
Published: April 2019

Despite growing research efforts on the preparation of (bio)functional liposomes, synthetic capsules cannot reach the densities of protein loading and the control over peptide display that is achieved by natural vesicles. Herein, a microbial platform for high‐yield production of lipidic nanovesicles with clickable thiol moieties in their outer corona is reported. These nanovesicles show low size dispersity, are decorated with a dense, perfectly oriented, and customizable corona of transmembrane polypeptides. Furthermore, this approach enables encapsulation of soluble proteins into the nanovesicles. Due to the mild preparation and loading conditions (absence of organic solvents, pH gradients, or detergents) and their straightforward surface functionalization, which takes advantage of the diversity of commercially available maleimide derivatives, bacteria‐based proteoliposomes are an attractive eco‐friendly alternative that can outperform currently used liposomes.
Enhanced Circularly Polarized Luminescence in Emissive Charge‐Transfer Complexes
Authors: Han Jianlei , Yang Dong , Jin Xue , Jiang Yuqian , Liu Minghua , Duan Pengfei
Published: April 2019

Achieving a large dissymmetry factor (glum) is a challenge in the field of circularly polarized luminescence (CPL). A chiral charge‐transfer (CT) system consisting of chiral electron donor and achiral electron acceptor shows bright circularly polarized emission with large glum value. The chiral emissive CT complexes could be fabricated through various approaches, such as grinding, crystallization, spin coating, and gelatinization, by simply blending chiral donor and achiral acceptor. The structural synergy originating from π–π stacking and strong CT interactions resulted in the long‐range ordered self‐assembly, enabling the formation of supramolecular gels. Benefiting from the large magnetic dipole transition moment in the CT state, the CPL activity of CT complexes exhibited large circular polarization. Our design strategy of the chiral emissive CT complexes is expected to help the development of new molecular engineering strategies for designing highly efficient CPL‐active materials.
Two‐Dimensional Layered Zinc Silicate Nanosheets with Excellent Photocatalytic Performance for Organic Pollutant Degradation and CO2 Conversion
Authors: Wang Lan , Bahnemann Detlef W. , Bian Liang , Dong Guohui , Zhao Jie , Wang Chuanyi
Published: April 2019

Two‐dimensional (2D) photocatalysts are highly attractive for their great potential in environmental remediation and energy conversion. Herein, we report a novel layered zinc silicate (LZS) photocatalyst synthesized by a liquid‐phase epitaxial growth route using silica derived from vermiculite, a layered silicate clay mineral, as both the lattice‐matched substrate and Si source. The epitaxial growth of LZS is limited in the 2D directions, thus generating the vermiculite‐type crystal structure and ultrathin nanosheet morphology with thicknesses of 8–15 nm and a lateral size of about 200 nm. Experimental observations and DFT calculations indicated that LZS has a superior band alignment for the degradation of organic pollutants and reduction of CO2 to CO. The material exhibited efficient photocatalytic performance for 4‐chlorophenol (4‐CP) degradation and CO2 conversion into CO and is the first example of a claylike 2D photocatalyst with strong photooxidation and photoreduction capabilities.
Imitation‐mussel‐based high‐performance conductive coating on hydrophobic fabric for thermochromic application
Authors: Wang Hao , Yue Lina , Wang Xiaowei , Deng Meigui , Sun Yingjuan , Gao Ming
Published: April 2019

On the basis of mussel inspiration, a common and low‐cost method for preparing a high‐performance poly‐3,4‐ethylene dioxythiophene (PEDOT) coating was proposed. First, cheap imitation‐mussel tannin–iron materials with universal adhesion properties were used as a modified coating on hydrophobic polypropylene nonwoven fabric. Because of the excellent wettability and ion chelating properties of the modified coating, a high‐performance PEDOT coating was successfully prepared later without complicated and expensive equipment. The PEDOT coating, with a conductivity of above 50 S/cm, could successfully realize the electric–thermal conversion at an appropriate current, and then, an obvious thermochromic effect on a pattern occurred; this is the key to achieving the functional textiles. The role of the artificial mussel adhesion materials in the modified coating were analyzed and are discussed. The results of this study provide new insight into preparing highly conductive coatings at low cost with potential practical applications in many fields. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47751.
The impact of fisheries management practices on the survival of the Yangtze finless porpoise in China
Authors: Mei Zhigang , Han Yi , Dong Lijun , Turvey Samuel T. , Hao Yujiang , Wang Kexiong , Wang Ding
Published: April 2019

The Critically Endangered Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) is facing a significant threat from illegal fishing in Poyang Lake and Dongting Lake, and current fisheries management has proved insufficient to eliminate illegal fishing.

A survey of local communities around the two lakes was conducted to investigate fishing activities and their potential impacts. Using a series of six scenarios derived from our data, we suggest that enhanced daytime patrols may have driven fishers to conduct compensatory night‐time fishing when the patrols are absent. Night‐time fishing activities overlap temporally with the main period of Yangtze finless porpoise foraging, so the potential intensification of night‐time fishing with the use of illegal gears could pose an increased threat to porpoises.

In addition to increasing law enforcement management efforts, helping fishers to secure alternative livelihoods may provide a more practical and sustainable long‐term method for reducing illegal fishing and its impacts on porpoises. This study also provides important lessons for conservation policy‐making and implementation for other cetacean species threatened by illegal fishing.
Globally exponentially stable attitude observer with Earth velocity estimation
Authors: Batista Pedro , Silvestre Carlos , Oliveira Paulo
Published: April 2019

This paper presents a novel observer for attitude estimation based on a triad of high‐grade rate gyros aided by a body‐fixed vector measurement of a constant inertial vector, departing from the majority of solutions that consider at least two of these vectors. A cascade approach is proposed, where the first block estimates a vector that is related to the angular velocity of the Earth and a second block estimates the attitude. While the topological characteristics are relaxed in the attitude observer so that global exponential stability is achieved, an additional stage is also devised that yields estimates directly on the special orthogonal group, preserving global convergence of the estimation error. Simulation results with realistic sensor noise were performed, including extensive Monte Carlo runs. These results illustrate the convergence of the proposed solution, as well as the achievable performance and robustness to sensor noise.
Feasibility study of Ulva sp. (Chlorophyta) intensive cultivation in a coastal area of the Eastern Mediterranean Sea
Authors: Chemodanov Alexander , Robin Arthur , Jinjikhashvily Gabriel , Yitzhak Dror , Liberzon Alexander , Israel Alvaro , Golberg Alexander
Published: April 2019

Increasing biomass production yields is a critical challenge for macroalgae biorefineries. The continuous tumbling and mixing of free‐floating algae through water or airflow has been shown to increase the productivity of algae in land‐based cultivation systems. This approach has not been tested thoroughly in offshore cultivation. We report, here, a field feasibility study on the increase in green macroalga Ulva sp. growth rates in offshore cages, achieved by the combined effect of tumbling and mixing of the algae using influxes of water and air. The experimental system was tested in a shallow coastal area in central Israel, in the eastern Mediterranean Sea. A maximum daily growth rate of 19.2%, areal productivity of 33.72 g dry weight (DW) day−1 m−2, and volumetric yields of 37.78 g DW day−1 m−3, together with 38.47 ± 0.01% ash and 5.28% protein content on a dry matter basis were achieved in the cages with intensified cultivation in the first week of May 2017. Our study shows that cultivation with tumbling and mixing of biomass with air, and water exchange with the environment is a feasible method to increase Ulva sp. biomass productivity offshore. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd
Real‐time monitoring and model‐based prediction of purity and quantity during a chromatographic capture of fibroblast growth factor 2
Authors: Sauer Dominik Georg , Melcher Michael , Mosor Magdalena , Walch Nicole , Berkemeyer Matthias , Scharl‐Hirsch Theresa , Leisch Friedrich , Jungbauer Alois , Dürauer Astrid
Published: April 2019

Process analytical technology combines understanding and control of the process with real‐time monitoring of critical quality and performance attributes. The goal is to ensure the quality of the final product. Currently, chromatographic processes in biopharmaceutical production are predominantly monitored with UV/Vis absorbance and a direct correlation with purity and quantity is limited. In this study, a chromatographic workstation was equipped with additional online sensors, such as multi‐angle light scattering, refractive index, attenuated total reflection Fourier‐transform infrared, and fluorescence spectroscopy. Models to predict quantity, host cell proteins (HCP), and double‐stranded DNA (dsDNA) content simultaneously were developed and exemplified by a cation exchange capture step for fibroblast growth factor 2 expressed in Escherichia coliOnline data and corresponding offline data for product quantity and co‐eluting impurities, such as dsDNA and HCP, were analyzed using boosted structured additive regression. Different sensor combinations were used to achieve the best prediction performance for each quality attribute. Quantity can be adequately predicted by applying a small predictor set of the typical chromatographic workstation sensor signals with a test error of 0.85 mg/ml (range in training data: 0.1–28 mg/ml). For HCP and dsDNA additional fluorescence and/or attenuated total reflection Fourier‐transform infrared spectral information was important to achieve prediction errors of 200 (2–6579 ppm) and 340 ppm (8–3773 ppm), respectively.
The role of mutual funds in the sustainable energy sector
Authors: Marti‐Ballester Carmen‐Pilar
Published: April 2019

The integration of renewable energy criteria in mutual fund investment decisions could channel private resources into the funding of environmentally related projects implemented by firms contributing to sustainable development. This paper examines the performance of European renewable energy funds that invest globally by comparing their risk‐adjusted returns with those achieved by black energy and conventional mutual funds. It uses Carhart's model on a sample of 81 renewable energy funds, 125 black energy funds, and 4,337 conventional mutual funds. The results indicate that 32.1% of renewable mutual funds—most of which adopt energy producers, renewable energy technology, and energy efficiency‐focused criteria—perform significantly better than the S&P Clean Energy market benchmark, this percentage being affected by the different states of the economy. However, none of them are able to beat the fossil fuel energy (S&P Global 1200 Energy Index) or conventional market benchmarks (S&P Global 1200 Index). Furthermore, 37.04% of renewable energy funds significantly underperform the S&P Global 1200 benchmark. Therefore, the investment in renewable energy funds has a financial cost for investors in relation to conventional fund investors.
Optimization of continuous purification of recombinant patchoulol synthase from Escherichia coli with membrane adsorbers
Authors: Brämer Chantal , Ekramzadeh Kimia , Lammers Frank , Scheper Thomas , Beutel Sascha
Published: April 2019

The natural production of patchouli oil in developing countries cannot meet the increasing demand any more. This leads to socioecological consequences, such as the use of arable land, which is actually intended for food. Hence, the world market price increased up to $150/kg. An alternative is the biotechnological production of patchouli oil using a multiproduct sesquiterpene synthase, the patchoulol synthase (PTS). Here, we report the optimization of recombinant PTS purification from Escherichia coli lysate using continuous immobilized metal affinity chromatography. First, the purification conditions of the batch process were optimized in regard to optimal buffer composition and optimized chromatographic conditions. The best purification result was achieved with Co2+‐immobilized metal affinity chromatography (Sartobind® IDA 75) with a triethanolamine buffer at pH 7, 0.5 M NaCl, 10% [vol/vol] glycerol, 5 mM MgCl2 and 250 mM imidazole for product elution. This optimized method was then transferred to a continuous chromatography system using three membrane adsorber units (surface of 75 cm2 each). Within 1.5 hr in total, 4.55 mg PTS with a final purity of 98% and recovery of 68% could be gained. The purified enzyme was used to produce 126 mg/L (‐)‐patchoulol from farnesyl pyrophosphate. Here, for the first time bioactive PTS was successfully purified using membrane adsorbers in a continuous downstream process.
Reciprocal modulation of cell functions upon direct interaction of adipose mesenchymal stromal and activated immune cells
Authors: Bobyleva Polina , Gornostaeva Aleksandra , Andreeva Elena , Ezdakova Mariia , Gogiya Badri , Buravkova Ludmila
Published: April 2019

The interaction of adipose mesenchymal stromal cells (ASCs) and allogeneic peripheral blood mononuclear cells (PBMCs) is regulated either through direct or paracrine mechanisms. Here, we examined the impact of direct contact in reciprocal regulation of ASC‐PBMC functions. Activated PBMCs in vitro induced ASC immunomodulatory activity, while direct and paracrine intercellular interactions regulated PBMCs themselves: the functional state of the organelles was altered, and activation decreased. Direct contact with immune cells affected the activity of ASC intracellular compartments, in particular, reactive oxygen species (ROS) production, and decreased the growth rate. Some ASC properties, including motility, intercellular adhesion molecule‐1 (ICAM‐1), and major histocompatibility complex class I and II antigens (HLA‐ABC and HLA‐DR, respectively) expression, did not depend on contact with PBMCs and were only regulated by paracrine means. Direct ASC and PBMC contact favoured an angiogenesis‐supportive microenvironment, possibly due to the greater production of VEGF by ASCs; this microenvironment also contained a higher leukemia inhibitory factor (LIF) level. Thus, a change in the functional activity of ASCs and PBMCs upon interaction promoted the formation of an immunosuppressive, anti‐inflammatory, and proangiogenic microenvironment. This environment could help resolve inflammation and further restore damaged tissue.

Significance of the study

Numerous studies have demonstrated the beneficial effects of transplanted mesenchymal stromal cells, particularly ASCs, for the treatment of a number of autoimmune diseases as well as various tissue injuries. To improve the efficiency of these methods, it is necessary to understand the principal events that occur when ASCs are introduced, primarily the molecular mechanisms of interaction between ASCs and the recipient immune system. We demonstrated that an anti‐inflammatory, immunosuppressive, and angiostimulatory shift in the paracrine profile upon the interaction of activated PBMCs and ASCs changes the functional activity of both cell types, a phenomenon that is potentiated by direct cell‐cell contact.
Stimuli‐Responsive DNA Self‐Assembly: From Principles to Applications
Authors: Yu Yang , Jin Bang , Li Yulin , Deng Zhaoxiang
Published: April 2019

Stimuli‐responsive DNA self‐assembly shares the advantages of both designed stimuli‐responsiveness and the molecular programmability of DNA structures, offering great opportunities for basic and applied research in dynamic DNA nanotechnology. In this minireview, we summarize the most recent progress in this rapidly developing field. The trigger mechanisms of the responsive DNA systems are first divided into six categories, which are then explained with illustrative examples following this classification. Subsequently, proof‐of‐concept applications in terms of biosensing, in vivo pH‐mapping, drug delivery, and therapy are discussed. Finally, we provide some remarks on the challenges and opportunities of this highly promising research direction in DNA nanotechnology.
Elektrochemische Reaktoren für die Wasserbehandlung
Authors: Muddemann Thorben , Haupt Dennis , Sievers Michael , Kunz Ulrich
Published: April 2019

Bei der Aufbereitung von (Ab‐)Wasser haben elektrochemische Verfahren verschiedene Vorteile gegenüber anderen Aufbereitungsmethoden. Sie sind robust, einfach in der Betriebsführung und flexibel bei Schwankungen der Abwasserfracht. Zudem kann ein relativ breites Spektrum an organischen und anorganischen Verunreinigungen entfernt werden. Dieser Beitrag gibt eine Übersicht zu den elektrochemischen Reaktoren, die in der Aufbereitung von Wasser, Prozesswasser und Abwasser bereits eingesetzt oder beforscht werden. Es werden zunächst einige wesentliche Grundlagen der elektrochemischen Verfahren zur Behandlung von Wasser vorgestellt und Beispiele für Anwendungen gegeben. Daran schließt sich die Beschreibung der verwendeten Reaktoren an.
Yoga for symptom management in oncology: A review of the evidence base and future directions for research
Authors: Danhauer Suzanne C. , Addington Elizabeth L. , Cohen Lorenzo , Sohl Stephanie J. , Van Puymbroeck Marieke , Albinati Natalia K. , Culos‐Reed S. Nicole
Published: April 2019

Because yoga is increasingly recognized as a complementary approach to cancer symptom management, patients/survivors and providers need to understand its potential benefits and limitations both during and after treatment. The authors reviewed randomized controlled trials (RCTs) of yoga conducted at these points in the cancer continuum (N = 29; n = 13 during treatment, n = 12 post‐treatment, and n = 4 with mixed samples). Findings both during and after treatment demonstrated the efficacy of yoga to improve overall quality of life (QOL), with improvement in subdomains of QOL varying across studies. Fatigue was the most commonly measured outcome, and most RCTs conducted during or after cancer treatment reported improvements in fatigue. Results also suggested that yoga can improve stress/distress during treatment and post‐treatment disturbances in sleep and cognition. Several RCTs provided evidence that yoga may improve biomarkers of stress, inflammation, and immune function. Outcomes with limited or mixed findings (eg, anxiety, depression, pain, cancer‐specific symptoms, such as lymphedema) and positive psychological outcomes (such as benefit‐finding and life satisfaction) warrant further study. Important future directions for yoga research in oncology include: enrolling participants with cancer types other than breast, standardizing self‐report assessments, increasing the use of active control groups and objective measures, and addressing the heterogeneity of yoga interventions, which vary in type, key components (movement, meditation, breathing), dose, and delivery mode.
Prevalence of germline variants in inflammatory breast cancer
Authors: Rana Huma Q. , Sacca Rosalba , Drogan Christine , Gutierrez Stephanie , Schlosnagle Emily , Regan Meredith M. , Speare Virginia , LaDuca Holly , Dolinsky Jill , Garber Judy E. , Overmoyer Beth A.
Published: April 2019

Background

Inflammatory breast cancer (IBC) is an uncommon and aggressive subtype of breast cancer associated with early disease recurrence and short survival. The prevalence of germline variants in cancer predisposition genes has not been systematically evaluated in women with IBC.

Methods

Among 301 women enrolled in the clinical IBC registry at a single institution between 2010 and 2017, 168 had documented genetic testing. A second cohort of 200 IBC cases who had panel‐based germline testing performed through a commercial testing laboratory from 2012 to 2017 was added to the analyses. Personal and family cancer histories and genetic testing results were evaluated when they were available for both cohorts.

Results

Among 501 IBC cases, 368 had documented genetic testing. Germline mutations (56 total) were identified in 53 cases (14.4%). BRCA1 or BRCA2 mutations were found in 7.3% of the subjects, 6.3% had a mutation in other breast cancer genes (PALB2, CHEK2, ATM, and BARD1), and 1.6% had mutations in genes not associated with breast cancer. The prevalence of mutations was 24% (22 of 92) among women with triple‐negative IBC, 13% (13 of 99) among women with estrogen receptor– and/or progesterone receptor–positive, human epidermal growth factor receptor 2 (HER2)–negative disease, and 9.3% (10 of 108) among women with HER2‐positive IBC.

Conclusions

The prevalence and diversity of germline genetic mutations among patients with IBC suggest that further studies should be performed to assess the role of inherited mutations in IBC carcinogenesis in comparison with non‐IBC breast cancer. Since IBC has a high metastatic potential associated with poor prognostic outcomes, proposed future studies may also inform targeted treatment options.
Pharmacokinetic Properties of Single and Multiple Doses of Ertugliflozin, a Selective Inhibitor of SGLT2, in Healthy Chinese Subjects
Authors: Li Yinhua , Mu Yuting , Shi Haihong , Liang Yali , Liu Zeyuan , Matschke Kyle , Hickman Anne , Krishna Rajesh , Sahasrabudhe Vaishali
Published: April 2019

Ertugliflozin, a sodium‐glucose cotransporter 2 inhibitor for the treatment of type 2 diabetes mellitus, prevents renal glucose reabsorption resulting in urinary glucose excretion. This open‐label, parallel cohort, randomized study conducted in healthy Chinese adults residing in China assessed the pharmacokinetics, tolerability, and safety of 5 mg and 15 mg of ertugliflozin following single (fasted condition) and multiple‐dose (fed condition) administration. Sixteen subjects were randomized and completed the study. Ertugliflozin absorption was rapid, with maximum plasma concentrations observed 1 hour after dosing under fasted conditions and 2 to 4 hours after dosing under fed conditions. Following single‐ and multiple‐dose administration, ertugliflozin exhibited dose‐proportional exposures with an apparent mean terminal half‐life of approximately 9.5 to 11.9 hours. Steady state was reached after 4 once‐daily doses. The accumulation ratio based on the area under the plasma concentration–time curve after multiple‐dose administration was approximately 1.3 and 1.2 for ertugliflozin 5 mg and 15 mg, respectively. Ertugliflozin was generally well tolerated following administration of single and multiple oral doses of 5 mg and 15 mg in healthy Chinese subjects. Pharmacokinetic comparison with non‐Asian subjects indicated that there are no clinically meaningful racial differences and no dose modification of ertugliflozin is required based on race or body weight.
Low vitamin D is associated with diabetes peripheral neuropathy in older but not in young and middle‐aged patients
Authors: Niu Yang , Li Ji , Peng Rongxia , Zhao Xuelin , Wu Jiang , Tang Qingya
Published: April 2019

Background

The relationship between vitamin D and diabetes peripheral neuropathy (DPN) is not consistent among epidemiologic studies. Thus, we aimed to investigate this relationship in different age groups.

Methods

In this cross‐sectional study, 1461 patients admitted to the Department of Endocrinology at Xinhua Hospital from June 2016 to September 2017 were divided into three age groups: a Youth group (24‐44 years, n = 127), a Middle‐age group (45‐64 years, n = 779), and an Elderly group (≥65 years, n = 555). Basic information and laboratory results were collected from medical records.

Results

Among the patients, 32.72% had DPN, with 12.59% in the Youth group, 33.63% in the Middle‐age group, and 36.04% in the Elderly group. For the total sample and the Elderly group, serum 25(OH)D concentrations in DPN patients were lower than in non‐DPN patients (P < .05). The results of multivariate logistic regression indicated a low vitamin D concentration to be a risk factor for DPN in the Elderly group (P < .05), but such relationship was not found in the Youth or Middle‐age groups. Moreover, according to ROC analysis, a serum 25(OH)D level < 34.87 nmol/L suggests the occurrence of DPN in elderly patients with type 2 diabetes (P < .001).

Conclusions

This study is the first to report that a low vitamin D level is associated with DPN in diabetic patients over 65 years of age and might be used as a predictor of DPN in this population. The interaction between vitamin D and age in the development of DPN and its underlying mechanisms need to be further explored.
Climate and lawn management interact to control C4 plant distribution in residential lawns across seven U.S. cities
Authors: Trammell Tara L. E. , Pataki Diane E. , Still Christopher J. , Ehleringer James R. , Avolio Meghan L. , Bettez Neil , Cavender‐Bares Jeannine , Groffman Peter M. , Grove Morgan , Hall Sharon J. , Heffernan James , Hobbie Sarah E. , Larson Kelli L. , Morse Jennifer L. , Neill Christopher , Nelson Kristen C. , O'Neil‐Dunne Jarlath , Pearse William D. , Chowdhury Rinku Roy , Steele Meredith , Wheeler Megan M.
Published: April 2019

In natural grasslands, C4 plant dominance increases with growing season temperatures and reflects distinct differences in plant growth rates and water use efficiencies of C3 vs. C4 photosynthetic pathways. However, in lawns, management decisions influence interactions between planted turfgrass and weed species, leading to some uncertainty about the degree of human vs. climatic controls on lawn species distributions. We measured herbaceous plant carbon isotope ratios (δ13C, index of C3/C4 relative abundance) and C4 cover in residential lawns across seven U.S. cities to determine how climate, lawn plant management, or interactions between climate and plant management influenced C4 lawn cover. We also calculated theoretical C4 carbon gain predicted by a plant physiological model as an index of expected C4 cover due to growing season climatic conditions in each city. Contrary to theoretical predictions, plant δ13C and C4 cover in urban lawns were more strongly related to mean annual temperature than to growing season temperature. Wintertime temperatures influenced the distribution of C4 lawn turf plants, contrary to natural ecosystems where growing season temperatures primarily drive C4 distributions. C4 cover in lawns was greatest in the three warmest cities, due to an interaction between climate and homeowner plant management (e.g., planting C4 turf species) in these cities. The proportion of C4 lawn species was similar to the proportion of C4 species in the regional grass flora. However, the majority of C4 species were nonnative turf grasses, and not of regional origin. While temperature was a strong control on lawn species composition across the United States, cities differed as to whether these patterns were driven by cultivated lawn grasses vs. weedy species. In some cities, biotic interactions with weedy plants appeared to dominate, while in other cities, C4 plants were predominantly imported and cultivated. Elevated CO2 and temperature in cities can influence C3/C4 competitive outcomes; however, this study provides evidence that climate and plant management dynamics influence biogeography and ecology of C3/C4 plants in lawns. Their differing water and nutrient use efficiency may have substantial impacts on carbon, water, energy, and nutrient budgets across cities.
American marten and fisher do not segregate in space and time during winter in a mixed‐forest system
Authors: Croose Elizabeth , Bled Florent , Fowler Nicholas L. , Beyer Jr Dean E. , Belant Jerrold L.
Published: April 2019

Understanding the mechanisms of coexistence between ecologically similar species is an important issue in ecology. Carnivore coexistence may be facilitated by spatial segregation, temporal avoidance, and differential habitat selection. American martens Martes americana and fishers Pekania pennanti are medium‐sized mustelids that occur sympatrically across portions of North America, yet mechanisms of coexistence between the two species are not fully understood. We assessed spatial and temporal partitioning in martens and fishers in the Upper Peninsula of Michigan, USA, using camera trap data collected during winter 2013–2015. To investigate spatial segregation, we used a dynamic occupancy model to estimate species’ occupancy probabilities and probabilities of persistence and colonization as a function of covariates and yearly occupancy probability for the other species. Temporal segregation was assessed by estimating diel activity overlap between species. We found weak evidence of spatial or temporal niche partitioning of martens and fishers. There was high overlap in forest cover selection, and both marten and fisher occupancy were positively correlated with deciduous forests (excluding aspen [Populus tremuloides]). There was strong temporal overlap (; CI = 0.79–0.82) with both species exhibiting largely crepuscular activity patterns. Co‐occurrence of martens and fishers appears to be facilitated by mechanisms not investigated in this study, such as partitioning of snow features or diet. Our results add additional insights into resource partitioning of mesocarnivores, but further research is required to enhance our understanding of mechanisms that facilitate marten and fisher coexistence.
Toward a mechanistic understanding of “peat collapse” and its potential contribution to coastal wetland loss
Authors: Chambers Lisa G. , Steinmuller Havalend E. , Breithaupt Joshua L.
Published: April 2019

Coastal wetlands are susceptible to loss in both health and extent via stressors associated with global climate change and anthropogenic disturbance. Peat collapse may represent an additional phenomenon contributing to coastal wetland loss in organic‐rich soils through rapid vertical elevation decline. However, the term “peat collapse” has been inconsistently used in the literature, leading to ambiguities regarding the mechanisms, timing, and spatial extent of its contribution to coastal wetland loss. For example, it is unclear whether peat collapse is distinct from general subsidence, or what biogeochemical changes or sequence of events may constitute peat collapse. A critical analysis of peer‐reviewed literature related to peat collapse was supplemented with fundamental principles of soil physics and biogeochemistry to develop a conceptual framework for coastal wetland peat collapse. We propose that coastal wetland peat collapse is a specific type of shallow subsidence unique to highly organic soils in which a loss of soil strength and structural integrity contributes to a decline in elevation, over the course of a few months to a few years, below the lower limit for emergent plant growth and natural recovery. We further posit that coastal wetland peat collapse is driven by severe stress or death of the vegetation, which compromises the supportive structure roots provide to low‐density organic soils and shifts the carbon balance of the ecosystem toward a net source, as mineralization is no longer offset by sequestration. Under these conditions, four mechanisms may contribute to peat collapse: (1) compression of gas‐filled pore spaces within the soil during dry‐down conditions; (2) deconsolidation of excessively waterlogged peat, followed by transport; (3) compaction of aerenchyma tissue in wetland plant roots, and possibly collapse of root channels; and (4) acceleration of soil mineralization due to the addition of labile carbon (dying roots), oxygen (decreased flooding), nutrients (eutrophication), or sulfate (saltwater intrusion). Scientists and land managers should focus efforts on monitoring vegetation health across the coastal landscape as an indicator for peat collapse vulnerability and move toward codifying the term “peat collapse” in the scientific literature. Once clarified, the contribution of peat collapse to coastal wetland loss can be evaluated.
The scale‐dependent effect of environmental filters on species turnover and nestedness in an estuarine benthic community
Authors: Menegotto André , Dambros Cristian S. , Netto Sérgio A.
Published: April 2019

Environmental filtering is a major mechanism structuring ecological communities. However, it is still not clear how different abiotic drivers composing the environmental filter interact with each other to determine local species assemblage and create spatial patterns in species distribution. Here, we evaluated the effects of two strong and uncorrelated environmental variables (salinity and sediment properties) on the β‐diversity of an estuarine macrobenthic community while accounting for spatial effects. Our results show that the benthic community composition has a strong spatial structure along the estuary, which can be greatly explained by salinity and sediment variation. Salinity is most associated with species replacement (turnover), whereas sediment is more important for species loss (nestedness). However, the effects of sediment variation on nestedness are mainly detected at a smaller spatial scale (estuarine sectors), whereas the effects of salinity on species turnover are stronger as spatial scale increases (entire estuary). Our findings suggest that environmental filters can drive both turnover and nestedness components of β‐diversity, but that their relative importance depends on the spatial scale of investigation. Although abiotic drivers associated with detrimental effects (sediment) usually result in nestedness, larger spatial scales encompass abiotic drivers associated with different suitable conditions (salinity), increasing the relative importance of the replacement component of species β‐diversity.
Bright lights in the big cities: migratory birds’ exposure to artificial light
Authors: Horton Kyle G , Nilsson Cecilia , Van Doren Benjamin M , La Sorte Frank A , Dokter Adriaan M , Farnsworth Andrew
Published: April 2019

Many species of migratory birds have evolved the ability to migrate at night, and the recent and rapid expansion of artificial light at night has markedly altered the nighttime sky through which they travel. Migrating birds regularly pass through heavily illuminated landscapes, and bright lights affect avian orientation. But risks to migrating birds from artificial light are not spatially or temporally uniform, representing a challenge for mitigating potential hazards and developing action plans to catalog risks at continental scales. We leveraged over two decades of remote‐sensing data collected by weather surveillance radar and satellite‐based sensors to identify locations and times of year when the highest numbers of migrating birds are exposed to light pollution in the contiguous US. Our continental‐scale quantification of light exposure provides a novel opportunity for dynamic and targeted conservation strategies to address the hazards posed by light pollution to nocturnally migrating birds.
Enhancing global change experiments through integration of remote‐sensing techniques
Authors: Shiklomanov Alexey N , Bradley Bethany A , Dahlin Kyla M , M Fox Andrew , Gough Christopher M , Hoffman Forrest M , M Middleton Elizabeth , Serbin Shawn P , Smallman Luke , Smith William K
Published: April 2019

Global change experiments are often spatially and temporally limited because they are time‐ and labor‐intensive, and expensive to carry out. We describe how the incorporation of remote‐sensing techniques into global change experiments can complement traditional methods and provide additional information about system processes. We describe five emerging near‐surface remote‐sensing techniques: spectroscopy, thermal and fluorescence imaging, terrestrial laser scanning, digital repeat photography, and unmanned aerial systems. The addition of such techniques can reduce cost and effort, provide novel information, and expand existing observations by improving their context, accuracy, and completeness. In addition, we contend that use of airborne and satellite remote‐sensing data during site selection can improve the ecological representativeness of future experiments. We conclude by recommending a high level of communication and collaboration between remote‐sensing scientists and ecologists at all stages of global change experimentation.
Chemical characterization and in vitro antioxidant and antimicrobial activities of essential oil from Commiphora wildii Merxm. (omumbiri) resin
Authors: Sheehama Jacobina T. , Mukakalisa Celine , Amakali Theopolina , Uusiku Lydia N. , Hans Renate H. , Nott Karen , Nott Amber , Louw Stefan
Published: April 2019

The resin of the plant Commiphora wildii Merxm. (omumbiri) is traditionally used by Ovahimba women (Kunene, Namibia) as the main ingredient for their perfume. Although essential oil produced from the resin by steam distillation is sold commercially, its detailed chemical composition and biological properties are not known. Knowledge on the potential antimicrobial and antioxidant activities of C. wildii essential oil is desired by perfume, cosmetics, and detergent manufacturers, in order to add value to their products when using the oil as an ingredient. Furthermore, once the oil has been chemically characterized, the concentrations of the bioactive constituents can be monitored for quality‐control purposes. In this study the chemical characterization of the volatile constituents of the essential oil of C. wildii resin was performed using gas chromatography–mass spectrometry (GC–MS) and GC coupled to a flame ionization detector (GC–FID). Fifty compounds were identified in the oil, most of which were terpenoids. The major compounds were α‐pinene (50.0% w/w), heptane (24.0% w/w), and β‐pinene (11.7% w/w). The antimicrobial activity of the oil was determined against Candida albicans, Escherichia coli, Klebsiella pneumaniaea, and Staphylococcus aureus. The best antimicrobial activity was noted against S. aureus, with a minimum inhibitory concentration (MIC) of 8 mg ml–1. Biofilm reduction was below 40%, but inhibition was between 93% (K. pneumaniaea) and 99% (C. albicans). An 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging assay revealed the antioxidant potential of the oil (with a half‐maximal inhibitory concentration, IC50, of 0.2257 mg ml–1).These results may be used by different industries to guide the formulation of their products and also to assess the safety of this oil when used as an ingredient.
Organ preservation for patients with anterior mucosal squamous cell carcinoma of the nasal cavity: Rhinectomy‐free survival in those refusing surgery
Authors: Mimica Ximena , Yu Yao , McGill Marlena , Barker Christopher A. , McBride Sean , Ganly Ian , Cracchiolo Jennifer R. , Dunn Lara A. , Katabi Nora , Sine Kevin , Mah Dennis , Lee Anna , Lee Nancy , Cohen Marc A.
Published: April 2019

Background

Standard treatment of squamous cell carcinoma (SCC) of the anterior nasal mucosa is surgical resection with or without postoperative radiation.

Methods

Retrospective review of patients diagnosed with SCC of the nasal cavity between January 2000 and July 2018 who refused total rhinectomy and who were treated with radiation with or without chemotherapy with curative intent.

Results

Eleven patients were identified, 73% had stage III or stage IV disease. Four patients were treated with intensity‐modulated radiotherapy and seven with intensity‐modulated proton radiotherapy. Concurrent chemoradiotherapy was used in nine patients (82%). With a median follow‐up of 15 months (3‐124 months), two patients experienced recurrence and one developed distant metastasis and died from disease. The 2‐year rhinectomy‐free survival rate was 88%. Two‐year overall survival and recurrence‐free survival were 100% and 75%, respectively.

Conclusion

A radiation‐based approach for SCC of the nasal cavity mucosa is a valid option for selected patients who refuse up‐front surgery.
Cholesterol Crystals in Hepatocyte Lipid Droplets Are Strongly Associated With Human Nonalcoholic Steatohepatitis
Authors: Ioannou George N. , Landis Charles S. , Jin Ga‐Young , Haigh W. Geoffrey , Farrell Geoffrey C. , Kuver Rahul , Lee Sum P. , Savard Christopher
Published: April 2019

It is unclear what drives the development of fibrosing nonalcoholic steatohepatitis (NASH). We aimed to determine whether cholesterol crystallization within hepatocyte lipid droplets (LDs) distinguishes patients with fibrosing NASH from patients with isolated hepatic steatosis and to study pathways leading to cholesterol accumulation in hepatocyte LDs. Patients with fibrosing NASH (n = 16) were compared to patients with isolated steatosis (n = 14). Almost all patients with fibrosing NASH had free cholesterol staining by filipin (16/16) and cholesterol crystals (15/16) in hepatocyte LDs, mostly in association with the LD membrane, compared to only 3/14 with cholesterol crystals and 3/14 with faint filipin staining in patients with isolated steatosis (P < 0.05). We were unable to identify significant differences in the expression of genes in liver tissue related to cholesterol homeostasis or LD proteins between patients with fibrosing NASH and isolated steatosis. Human hepatoma cell line (HepG2) cells were supplemented with low‐density lipoprotein (LDL)‐cholesterol and oleic acid to develop large LDs, similar to those observed in patients with NASH. Fluorescent markers were used to track the uptake and intracellular trafficking of LDL‐cholesterol. LDL‐cholesterol was taken up by HepG2 cells and transported through the endosomal‐lysosomal compartment directly to LDs, suggesting direct contact sites between late endosomes and LDs. Exposure of HepG2 cells to LDL‐cholesterol resulted in a high concentration of cholesterol and cholesterol crystallization in LDs. Conclusion: Excess cholesterol is stored in the liver primarily within hepatocyte LDs where it can crystallize. Our findings are best explained by direct transport of cholesterol from late endosomes/lysosomes to LDs in hepatocytes. We found a strong association between the presence of LD cholesterol crystals and the development of fibrosing NASH in humans, suggesting a causal relationship.
Association of ERAP2 gene variants with risk of pre‐eclampsia among Iranian women
Authors: Soltani Sareh , Nasiri Mahboobeh
Published: April 2019

Objectives

To determine the association between ERAP2 rs2549782 and rs17408150 polymorphisms and pre‐eclampsia among Iranian women.

Methods

A retrospective case–control study comparing 319 women with pre‐eclampsia and 291 normotensive pregnant Iranian women between January and August 2016. Pre‐eclampsia was diagnosed by the International Society for the Study of Hypertension in Pregnancy's criteria. Demographic data were collected by oral interview. Genotyping was done by allele‐specific PCR. Data were analyzed using SPSS v. 16.

Results

The frequency of the rs2549782TT genotype was 31.0% and 27.5% among cases and controls, respectively (P=0.006). There was no difference in the frequency of the T allele between groups (P>0.05). Regarding the rs17408150 polymorphism, a high portion of women with pre‐eclampsia was homozygous for the AA genotype (P<0.001). The frequency of the A allele was 32.5% and 25.05% among cases and controls, respectively (P=0.004). The combined haplotype of the rs2549782A and rs17408150G alleles was associated with increased risk of pre‐eclampsia (P=0.031).

Conclusion

ERAP2 gene polymorphisms were associated with the risk of pre‐eclampsia in an Iranian population. The results provide further evidence of the role of ERAP2 in the pathophysiology of this disease.
Cardiac risk prediction model for pregnant women with structural heart disease in Eastern China
Authors: Fu Qin , Wang Xiao‐Jin , Wang Bing‐Shun , Lin Jian‐Hua
Published: April 2019

Objective

To develop a model for predicting cardiac risk among pregnant women with structural heart disease in Eastern China.

Methods

The model was built using data from pregnant women (development cohort, n=566; validation cohort, n=314) who delivered at Shanghai Obstetrical Cardiology Intensive Care Center, Renji Hospital, Shanghai, between 2002 and 2015. Independent predictors of adverse cardiac events were determined by logistic regression. Discrimination and calibration of the model, termed the Renji score, were compared with the CARPREG score, ZAHARA score, and modified WHO risk classification.

Results

There were 87 (15.4%) adverse cardiac events in the development cohort. Independent predictors of adverse cardiac events included left ventricular systolic dysfunction (ejection fraction, <40%), prior cardiac event or arrhythmia, moderate‐to‐severe pulmonary arterial hypertension (≥50 mm Hg), mechanical valve replacement, moderate‐to‐severe mitral stenosis. Surgical intervention before pregnancy was protective against cardiac events. As compared with other risk assessment systems, the Renji score performed better in predicting cardiac events, with a concordance statistic of 0.844 (95% confidence interval [CI], 0.800–0.889) for the development cohort and 0.779 (95% CI, 0.684–0.873) for the validation cohort.

Conclusion

The Renji score was applicable to predicting cardiac events among pregnant women with structural heart disease in Eastern China.