bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of amino acid substitution in the hydrophobic face of amphiphilic peptides on membrane curvature and perturbation: N‐terminal helix derived from adenovirus internal protein VI as a model
Authors: Murayama Tomo , Pujals Sílvia , Hirose Hisaaki , Nakase Ikuhiko , Futaki Shiroh
Published: June 2016

The N‐terminal amphipathic helical segment of adenovirus internal protein VI (AdVpVI) plays a critical role in viral infection. Here, we report that the peptide segment corresponding to AdVpVI (positions 33–55) can induce positive membrane curvature together with membrane perturbation. The enhanced perturbation ability of the peptide was observed for membranes containing negatively charged phospholipids. Based on the liposome leakage assay, substitution of leucine at position 40 to other aliphatic (isoleucine) and aromatic (phenylalanine and tryptophan) residues yielded a similar degree of membrane perturbation by the peptides, which was considerably diminished by the substitution to glutamine. Further studies using the wild‐type AdVpVI (33–55) (WT) and phenylalanine‐substituted peptides (L40F) demonstrated that both peptides have positive membrane‐curvature‐inducing ability. These peptides showed higher binding affinity to 50‐nm large unilamellar vesicles (LUVs) than to 200‐nm LUVs. However, no enhanced perturbation by these peptides was observed for 50‐nm LUVs compared to 200‐nm LUVs, suggesting that both the original membrane curvature and the additional strain due to peptide insertion affect the membrane perturbation ability of these peptides. In the case of L40F, this peptide rather had a lower membrane perturbation ability for 50‐nm LUVs than for 200‐nm LUVs, which can be attributed to possible shallower binding of L40F on membranes. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 430–439, 2016.
Identifying a robust design space for glycosylation during monoclonal antibody production
Authors: St. Amand Melissa M. , Hayes James , Radhakrishnan Devesh , Fernandez Janice , Meyer Bill , Robinson Anne S. , Ogunnaike Babatunde A.
Published: June 2016

Glycan distribution has been identified as a “critical quality attribute” for many biopharmaceutical products, including monoclonal antibodies. Consequently, determining quantitatively how process variables affect glycan distribution is important during process development to control antibody glycosylation. In this work, we assess the effect of six bioreactor process variables on the glycan distribution of an IgG1 produced in CHO cells. Our analysis established that glucose and glutamine media concentration, temperature, pH, agitation rate, and dissolved oxygen (DO) had small but significant effects on the relative percentage of various glycans. In addition, we assessed glycosylation enzyme transcript levels and intracellular sugar nucleotide concentrations within the CHO cells to provide a biological explanation for the observed effects on glycan distributions. From these results we identified a robust operating region, or design space, in which the IgG1 could be produced with a consistent glycan distribution. Since our results indicate that perturbations to bioreactor process variables will cause only small (even if significant) changes to the relative percentage of various glycans (<±1.5%)—changes that are too small to affect the bioactivity and efficacy of this IgG1 significantly—it follows that the glycan distribution obtained will be consistent even with relatively large variations in bioreactor process variables. However, for therapeutic proteins where bioactivity and efficacy are affected by small changes to the relative percentage of glycans, the same analysis would identify the manipulated variables capable of changing glycan distribution, and hence can be used to implement a glycosylation control strategy. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1149–1162, 2016
A scoping review of the nurse practitioner workforce in oncology
Authors: Coombs Lorinda A. , Hunt Lauren , Cataldo Janine
Published: June 2016

The quality of cancer care may be compromised in the near future because of work force issues. Several factors will impact the oncology health provider work force: an aging population, an increase in the number of cancer survivors, and expansion of health care coverage for the previously uninsured. Between October 2014 and March 2015, an electronic literature search of English language articles was conducted using PubMed®, the Cumulative Index to Nursing and Allied Health Sciences (CINAHL®), Web of Science, Journal Storage (JSTOR®), Google Scholar, and SCOPUS®. Using the scoping review criteria, the research question was identified “How much care in oncology is provided by nurse practitioners (NPs)?” Key search terms were kept broad and included: “NP” AND “oncology” AND “workforce”. The literature was searched between 2005 and 2015, using the inclusion and exclusion criteria, 29 studies were identified, further review resulted in 10 relevant studies that met all criteria. Results demonstrated that NPs are utilized in both inpatient and outpatient settings, across all malignancy types and in a variety of roles. Academic institutions were strongly represented in all relevant studies, a finding that may reflect the Accreditation Council for Graduate Medical Education (ACGME) duty work hour limitations. There was no pattern associated with state scope of practice and NP representation in this scoping review. Many of the studies reviewed relied on subjective information, or represented a very small number of NPs. There is an obvious need for an objective analysis of the amount of care provided by oncology NPs.
Sorafenib treatment in children with relapsed and refractory neuroblastoma: an experience of four cases
Authors: Okada Keiko , Nakano Yoshiko , Yamasaki Kai , Nitani Chika , Fujisaki Hiroyuki , Hara Junichi
Published: June 2016

Metastatic neuroblastoma is an aggressive malignancy with a poor prognosis. Recent findings have shown that sorafenib decreases cell viability and increases apoptosis in human neuroblastoma cell lines. We report an experience of compassionate use of sorafenib in children with treatment‐refractory neuroblastoma. Sorafenib showed transient anti‐tumor activity in all four patients without adverse effects. However, progression was observed after a short stabilization phase. While sorafenib showed minimal anti‐tumor activity in our patients, it might still be effective in patients with neuroblastoma in an earlier stage.
Investigations on the Antimony Promotional Effect on CeO2–WO3/TiO2 for Selective Catalytic Reduction of NOx with NH3
Authors: Yan Lijun , Liu Yangyang , Hu Hang , Li Hongrui , Shi Liyi , Zhang Dengsong
Published: June 2016

Antimony‐doped CeO2–WO3/TiO2 catalysts were prepared by a conventional ultrasonic‐assisted impregnation method and employed for selective catalytic reduction of NOx with NH3 at low temperature. Both experimental work and theoretical studies were employed to elucidate the effect of the antimony on promoting the CeO2–WO3/TiO2 catalyst. The catalytic activity of CeO2–WO3/TiO2 was largely improved after the addition of antimony oxide. It was found that antimony doping reduced the crystal size and strengthened the synergistic effect between the metal cations, which resulted in a favorable catalyst surface status with abundant active surface oxygen, Brønsted acid sites, and effective electron transfer. Both in situ diffuse reflectance infrared Fourier transform analysis and DFT calculation results revealed that the ammonia and NOx desorption behavior over the catalyst surface were considerably different. For the ammonia species, rather large amounts of the active NH4+ and NH3 species anchored on the surface of the Sb‐doped CeO2–WO3/TiO2. In view of the NOx species, the amount of nonactive bidentate nitrate species was largely reduced and the amount of active gaseous NO2 species was clearly enhanced, which lowered the activation energy of the catalytic process and gave rise to the elevated low‐temperature NH3 selective catalytic reduction activity. All these preferable properties resulted in the elevated de‐NOx activity of the Sb‐doped CeO2–WO3/TiO2 catalyst.
Social media integration in electronic human resource management: Development of a social eHRM framework
Authors: Arjomandy Danial
Published: June 2016

Social media has dramatically changed how we communicate both in life and in business. Accordingly, I conducted a qualitative analysis of electronic Human Resource Management (eHRM) practices involving social media. The sample consists of 16 organizations varying in size (e.g., Fortune 500 vs. small enterprises), industry (e.g., product vs. service‐based) and sector (public vs. private). Based on the review, I developed a Social Participation Framework involving two dimensions—openness and stratification— that are reflective of variations in the user domains associated with a given application. The combination of these dimensions yielded four alternative models of social media eHRM implementations: open, internal, specialized, and segmented. These in turn tended to be associated with different types of eHRM goals. A best practice example of each model is provided, and opportunities for future research are identified. Copyright © 2016 ASAC. Published by John Wiley & Sons, Ltd.
A High‐Voltage and High‐Capacity Li1+xNi0.5Mn1.5O4 Cathode Material: From Synthesis to Full Lithium‐Ion Cells
Authors: Mancini Marilena , Axmann Peter , Gabrielli Giulio , Kinyanjui Michael , Kaiser Ute , Wohlfahrt‐Mehrens Margret
Published: June 2016

We report Co‐free, Li‐rich Li1+xNi0.5Mn1.5O4 (0<x<1) compounds as high‐voltage and high‐capacity cathode materials for Li‐ion cells. Their tailored morphology allows high density and facile processability for electrode development. In the potential range 2.4–4.9 V, the cathode material of composition Li1.5Ni0.5Mn1.5O4 shows excellent performance in terms of capacity and cycling stability in half‐cells. In addition, for the first time, we demonstrate the application of the high‐voltage and high‐capacity cathode in full Li‐ion cells with graphite anodes with very high cycling stability. The electrochemical performance and low cost of the cathode material, together with the feasibility of a chemical method to obtain Li‐rich Li1+xNi0.5Mn1.5O4 (0<x<1), make practical applications of high‐energy density Li‐ion batteries possible.
Efficient Regular Perovskite Solar Cells Based on Pristine [70]Fullerene as Electron‐Selective Contact
Authors: Collavini Silvia , Kosta Ivet , Völker Sebastian F. , Cabanero German , Grande Hans J. , Tena‐Zaera Ramón , Delgado Juan Luis
Published: June 2016

Invited for this month′s cover is the group of Juan‐Luis Delgado at the University of the Basque Country. The image represents the current competing scenario between fullerenes and TiO2 as electron‐transport materials for perovskite solar cells. The Full Paper itself is available at 10.1002/cssc.201600051.
Contribution of high‐content imaging technologies to the development of anti‐infective drugs
Authors: Ang Michelle Lay Teng , Pethe Kevin
Published: June 2016

Originally developed to study fundamental aspects of cellular biology, high‐content imaging (HCI) was rapidly adapted to study host–pathogen interactions at the cellular level and adopted as a technology of choice to unravel disease biology. HCI platforms allow for the visualization and quantification of discrete phenotypes that cannot be captured using classical screening approaches. A key advantage of high‐content screening technologies lies in the possibility to develop and interrogate physiologically significant, predictive ex vivo disease models that reproduce complex conditions relevant for infection. Here we review and discuss recent advances in HCI technologies and chemical biology approaches that are contributing to an increased understanding of the intricate host–pathogen interrelationship on the cellular level, and which will foster the development of novel therapeutic approaches for the treatment of human bacterial and protozoan infections. © 2016 The Authors. Cytometry Part A published by Wiley Periodicals, Inc. on behalf of ISAC
Reinforced masonry beams under shear load – Proposals for future designs / Bewehrte schubbeanspruchte Mauerwerksbalken – Vorschläge für zukünftige Bemessungen
Authors: Gunkler Erhard , Marx Johann Jakob
Published: June 2016

This article is written against the backdrop of the work of the European standardisation committees on the amendment of EN 1996‐1‐1 [N 4] which will also exert an influence on the design of reinforced masonry in Germany.

This paper focusses on the design approaches of DIN EN 1996‐1‐1 for untensioned reinforced masonry beams under shear load in the ultimate limit state (ULS). Proposals are made to discuss their revision. The contents of E DIN 1053‐3 [N 3] and of the final draft of the guideline ”Flat Lintels” [7] are taken into account.
Closed‐loop recycling of autoclaved aerated concrete / Geschlossener Recyclingkreislauf für Porenbeton
Authors: Kreft Oliver
Published: June 2016

Xella Technology and Research, in a pilot study with the Hamburg‐based Otto Dörner GmbH waste management company and the Ytong plant in Wedel, has been testing since 2013 how and in what amounts autoclaved aerated concrete (AAC) remains from demolished buildings or from waste disposal sites can be reused for new AAC production. The processing of the salvaged AAC‐material should conform to the current technical standard: return of mixed demolition rubble, separation of contaminants (by metal separation, air density separation, swim‐sink separation, manual resorting), pre‐treatment in the crusher and sieves for predetermined grain size ranges. This is where grain sizes or moisture content, heavy metals, bitumen, sulphate or other impurities are analysed in detail. The sorting accuracy as performed by Otto Dörner has shown to be sufficient for reuse through reintroduction into AAC‐production. Up to 15 % salvaged AAC prepared in such a manner can be effortlessly reused. A sample production of AAC quality grade P4‐0.55 with granulated salvaged AAC in the Ytong plant in Wedel was successful.
Development of a clinker brick façade to exploit solar thermal energy / Entwicklung einer Klinkerfassade zur Nutzung solarer Wärmeenergie
Authors: Mähner Dietmar , Lengers Jacob , Brand Carina
Published: June 2016

The featured research project was intended to develop and test a specially modified brick façade, which would convert solar radiation on the façade into thermal energy for heating purposes. The main objective was to measure the energy extraction potential but all other issues concerning technical feasibility also had to be taken into account.

To this end a masonry structure had to be developed, which allowed integration of the inserted pipe to dissipate the energy introduced, while allowing simple, practicable installation. Various tests were carried out on masonry walls and individual bricks.

On sunny winter days, an energy extraction potential of 1.9 kWh per square metre of façade and day was measured. During summer days, an extraction potential of up to 2.6 kWh/(m2·d) could be observed. The initial findings allow the assumption that this energy could be utilized with the use of a heat pump.
Example calculation of the sound insulation of a floor slab between residential units according to DIN 4109‐2:2016 / Beispielhafte Berechnung der Luftschalldämmung einer Wohnungstrenndecke im Mauerwerkbau nach DIN 4109‐2:2016
Authors: Naumann Kai , Schoch Torsten
Published: June 2016

The DIN 4109 series of standards has been revised in recent years and harmonised with European design codes. After the drafts of DIN 4109 were issued in November 2013, the documents shall now be finally published in summer 2016.

The calculation procedure according to DIN 4109‐2 is based on the simplified procedure from EN 12354:2000, in which the noise transmission routes are calculated individually, similarly to the calculation for framed buildings according to supplement 1 to DIN 4109. The procedure according to DIN 4109‐2 is based on formulae, which are filled with figures from the building element catalogue of parts 3‐2 to 3‐6.

This article shows examples of calculation steps for the determination of the weighted airborne sound reduction R'w,Raccording to DIN 4109‐2:2016 for a floor slab between residential units.
Blocking elevated VEGF‐A attenuates non‐vasculature Fragile X syndrome abnormalities
Authors: Belagodu Amogh P. , Zendeli Liridon , Slater Bernard J. , Galvez Roberto
Published: June 2016

Fragile X syndrome (FXS) is the most common form of inherited mental retardation. In exploring abnormalities associated with the syndrome, we have recently demonstrated abnormal vascular density in a FXS mouse model (Galvan and Galvez, ). One of the most prominent regulators of vascular growth is VEGF‐A (Vascular Endothelial Growth Factor A), suggesting that FXS is associated with abnormal VEGF‐A expression. In addition to its role in vascular regulation, VEGF‐A also induces cellular changes such as increasing cell proliferation, and axonal and neurite outgrowth independent of its effects on vasculature. These VEGF‐A induced cellular changes are consistent with FXS abnormalities such as increased axonal material, dendritic spine density, and cell proliferation. In support of these findings, the following study demonstrated that FXS mice exhibit increased expression of VEGF‐A in brain. These studies suggest that increased VEGF‐A expression in FXS is contributing to non‐vascular FXS abnormalities. To explore the role of VEGF‐A in mediating non‐vascular FXS abnormalities, the monoclonal antibody Bevacizumab was used to block free VEGF‐A. Bevacizumab treatment was found to decrease FXS Synapsin‐1 expression, a presynaptic marker for synapse density, and reduce FXS testicle weight to control levels. Blocking VEGF‐A also alleviated FXS abnormalities on novel object recognition, a test of cognitive performance. These findings demonstrate that VEGF‐A is elevated in FXS brain and suggest that its expression promotes non‐vascular FXS abnormalities. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 14–25, 2017
Defining the identity of mouse embryonic dermal fibroblasts
Authors: Budnick Isadore , Hamburg‐Shields Emily , Chen Demeng , Torre Eduardo , Jarrell Andrew , Akhtar‐Zaidi Batool , Cordovan Olivia , Spitale Rob C. , Scacheri Peter , Atit Radhika P.
Published: June 2016

Embryonic dermal fibroblasts in the skin have the exceptional ability to initiate hair follicle morphogenesis and contribute to scarless wound healing. Activation of the Wnt signaling pathway is critical for dermal fibroblast fate selection and hair follicle induction. In humans, mutations in Wnt pathway components and target genes lead to congenital focal dermal hypoplasias with diminished hair. The gene expression signature of embryonic dermal fibroblasts during differentiation and its dependence on Wnt signaling is unknown. Here we applied Shannon entropy analysis to identify the gene expression signature of mouse embryonic dermal fibroblasts. We used available human DNase‐seq and histone modification ChiP‐seq data on various cell‐types to demonstrate that genes in the fibroblast cell identity signature can be epigenetically repressed in other cell‐types. We found a subset of the signature genes whose expression is dependent on Wnt/β‐catenin activity in vivo. With our approach, we have defined and validated a statistically derived gene expression signature that may mediate dermal fibroblast identity and function in development and disease. genesis 54:415–430, 2016. © 2016 Wiley Periodicals, Inc.
Circumpolar habitat use in the southern elephant seal: implications for foraging success and population trajectories
Authors: Hindell Mark A. , McMahon Clive R. , Bester Marthán N. , Boehme Lars , Costa Daniel , Fedak Mike A. , Guinet Christophe , Herraiz‐Borreguero Laura , Harcourt Robert G. , Huckstadt Luis , Kovacs Kit M. , Lydersen Christian , McIntyre Trevor , Muelbert Monica , Patterson Toby , Roquet Fabien , Williams Guy , Charrassin Jean‐Benoit
Published: June 2016

In the Southern Ocean, wide‐ranging predators offer the opportunity to quantify how animals respond to differences in the environment because their behavior and population trends are an integrated signal of prevailing conditions within multiple marine habitats. Southern elephant seals in particular, can provide useful insights due to their circumpolar distribution, their long and distant migrations and their performance of extended bouts of deep diving. Furthermore, across their range, elephant seal populations have very different population trends. In this study, we present a data set from the International Polar Year project; Marine Mammals Exploring the Oceans Pole to Pole for southern elephant seals, in which a large number of instruments (N = 287) deployed on animals, encompassing a broad circum‐Antarctic geographic extent, collected in situ ocean data and at‐sea foraging metrics that explicitly link foraging behavior and habitat structure in time and space. Broadly speaking, the seals foraged in two habitats, the relatively shallow waters of the Antarctic continental shelf and the Kerguelen Plateau and deep open water regions. Animals of both sexes were more likely to exhibit area‐restricted search (ARS) behavior rather than transit in shelf habitats. While Antarctic shelf waters can be regarded as prime habitat for both sexes, female seals tend to move northwards with the advance of sea ice in the late autumn or early winter. The water masses used by the seals also influenced their behavioral mode, with female ARS behavior being most likely in modified Circumpolar Deepwater or northerly Modified Shelf Water, both of which tend to be associated with the outer reaches of the Antarctic Continental Shelf. The combined effects of (1) the differing habitat quality, (2) differing responses to encroaching ice as the winter progresses among colonies, (3) differing distances between breeding and haul‐out sites and high quality habitats, and (4) differing long‐term regional trends in sea ice extent can explain the differing population trends observed among elephant seal colonies.
Intraguild predation by shore crabs affects mortality, behavior, growth, and densities of California horn snails
Authors: Lorda J. , Hechinger R. F. , Cooper S. D. , Kuris A. M. , Lafferty K. D.
Published: June 2016

The California horn snail, Cerithideopsis californica, and the shore crabs, Pachygrapsus crassipes and Hemigrapsus oregonensis, compete for epibenthic microalgae, but the crabs also eat snails. Such intraguild predation is common in nature, despite models predicting instability. Using a series of manipulations and field surveys, we examined intraguild predation from several angles, including the effects of stage‐dependent predation along with direct consumptive and nonconsumptive predator effects on intraguild prey. In the laboratory, we found that crabs fed on macroalgae, snail eggs, and snails, and the size of consumed snails increased with predator crab size. In field experiments, snails grew less in the presence of crabs partially because snails behaved differently and were buried in the sediment (nonconsumptive effects). Consistent with these results, crab and snail abundances were negatively correlated in three field surveys conducted at three different spatial scales in estuaries of California, Baja California, and Baja California Sur: (1) among 61 sites spanning multiple habitat types in three estuaries, (2) among the habitats of 13 estuaries, and (3) among 34 tidal creek sites in one estuary. These results indicate that shore crabs are intraguild predators on California horn snails that affect snail populations via predation and by influencing snail behavior and performance.
Synergistic effects of climate change and grazing on net primary production of Mongolian grasslands
Authors: Dangal Shree R. S. , Tian Hanqin , Lu Chaoqun , Pan Shufen , Pederson Neil , Hessl Amy
Published: June 2016

In arid and semi‐arid regions, grassland degradation has become a major environmental and economic problem, but little information is available on the response of grassland productivity to both climate change and grazing intensity. By developing a grazing module in a process‐based ecosystem model, the dynamic land ecosystem model (DLEM), we explore the roles of climate change, elevated CO2, and varying grazing intensities in affecting aboveground net primary productivity (ANPP) across different grassland sites in Mongolia. Our results show that both growing season precipitation totals and average temperature exert important controls on annual ANPP across six sites over a precipitation gradient, explaining 65% and 45% of the interannual variations, respectively. Interannual variation in ANPP, measured as the ratio of standard deviation among years to long‐term mean, increased from 9.5 to 18.9% to 23.9–32.5% along a gradient of high to low precipitation. Historical grazing resulted in a net reduction in ANPP across all sites ranging from 2% to 15.4%. Our results further show that grassland ANPP can be maintained at a grazing intensity of 1.0 and 0.5 sheep/ha at wet and dry sites, respectively, indicating that dry sites are more vulnerable to grazing compared to wet sites. In addition, precipitation use efficiency (PUE) decreased while nitrogen use efficiency (NUE) increased across a gradient of low to high precipitation. However, grazing resulted in a net reduction in both PUE and NUE by 47% and 67% across all sites. Our results indicate that seasonal precipitation totals, average temperatures and grazing are important regulators of grassland ANPP in Mongolia. These results have important implications for grassland productivity in semi‐arid regions in Central Asia and beyond.
Later at higher latitudes: large‐scale variability in seabird breeding timing and synchronicity
Authors: Burr Zofia M. , Varpe Øystein , Anker‐Nilssen Tycho , Erikstad Kjell Einar , Descamps Sébastien , Barrett Robert T. , Bech Claus , Christensen‐Dalsgaard Signe , Lorentsen Svein‐Håkon , Moe Børge , Reiertsen Tone Kristin , Strøm Hallvard
Published: June 2016

In seasonal environments, organisms are expected to optimally schedule reproduction within an annual range of environmental conditions. Latitudinal gradients generate a range of seasonality to which we can expect adaptations to have evolved, and can be used to explore drivers of timing strategies across species’ distribution ranges. This study compares the timing of egg hatching in four seabird species (Atlantic puffin Fratercula arctica, black‐legged kittiwake Rissa tridactyla, common guillemot Uria aalge, and Brünnich's guillemot U. lomvia) covering a subarctic to Arctic latitudinal gradient along the Norwegian coast to Svalbard (65–79°N). Hatching was significantly delayed by an estimated 1.7, 2.3, and 1.9 d per latitudinal degree for puffins, kittiwakes, and common guillemots, respectively, but was not delayed for Brünnich's guillemots. Hatching distributions revealed an increase in intra‐annual breeding synchronicity along a latitudinal gradient for kittiwakes only, whereas the two guillemots exhibited high hatching synchronicity at all colonies. We used this large‐scale, multispecies timing data series to discuss constraints, adaptations, and mechanisms affecting breeding timing, a necessary step to recognize risks to populations and predict future ecosystem change.
Survival and growth of three afforestation species under high saline drip irrigation in the Taklimakan Desert, China
Authors: Zhang J. G. , Lei J. Q. , Wang Y. D. , Zhao Y. , Xu X. W.
Published: June 2016

Afforestation of shelterbelts is a sustainable practice to protect highways from shifting sand dunes in desert areas. The Taklimakan Desert Highway Shelterbelt (TDHS) in China is known as “the Great Green Wall of Taklimakan Desert” and borders a 436‐km distance along the highway. This study assessed the early survival, above‐ground growth, and root growth of three salt‐ and drought‐tolerant plant species (Calligonum aborescensLitv., Tamarix ramosissimaLedeb.,andHaloxylon ammodendron(C. A. Mey.) Bunge) inTDHS; those were drip‐irrigated with local high saline groundwater. The results demonstrated that more than 80% ofHaloxylon ammodendronseedlings could survive regardless of irrigation water salinities ranging from 2.82 to 29.70 g/L. In contrast, survival rates ofCalligonum aborescensseedlings were greater than 65% when using irrigation water salinities ≤13.99 g/L and less than 50% when irrigated with water having salinities of 20.99–29.70 g/L, respectively. However, plant survival rates ofTamarix ramosissimawere much lower than 50% when irrigated with water having salinities >4.82 g/L. Furthermore, under the same salinity, the height, crown width, and maximum width of basal stems were the greatest forCalligonum aborescensplants and the lowest forTamarix ramosissimaplants. Root length varied among the species depending on tree age and the applied water characteristics. We conclude that afforestation is feasible with saline water in this extreme arid shifting desert, particularlyCalligonum aborescensplants should be grown at the outer margin of the shelterbelt due to its faster growth to more quickly stabilize the shifting sand. Our study may provide a good resolution for afforestation and marginal saline water utility in most arid and semiarid regions.
Non‐native Chinese mystery snail (Bellamya chinensis) supports consumers in urban lake food webs
Authors: Twardochleb Laura A. , Olden Julian D.
Published: June 2016

Non‐native species are widely regarded as threats to ecosystem structure and function; however, these species may also provide benefits to ecosystems that have lost former functions to environmental degradation. This study evaluated whether non‐native species provide prey resources or induce trophic cul‐de‐sacs (by diverting basal energy away from higher trophic levels) in developed ecosystems where native prey are in decline. We used stable isotopes of 13C, 15N, and 2H to assess whether non‐native Chinese Mystery snail (Bellamya chinensis) provides a prey resource to consumers, and maintains the integration of benthic resources into food webs of lakes subjected to lakeshore development. Regardless of Bellamya presence, consumers in undeveloped lakes were supported primarily by benthic resources, and lakeshore development dramatically reduced consumer reliance on these resources. This was at least partly due to a reduction in the availability of native snails, a high‐quality prey item, to the dominant littoral consumer, molluscivorous pumpkinseed sunfish (Lepomis gibbosus). In developed lakes with non‐native Bellamya, generalist yellow perch (Perca flavescens) and piscivorous largemouth bass (Micropterus salmoides) consumed benthic resources in proportions similar to undeveloped lakes, and pumpkinseed sunfish consumed Bellamya in higher proportions than in undeveloped lakes. Thus, Bellamya provided a prey substitute in developed lakes where native snail populations were depressed; and Bellamya's influence extended to higher trophic‐level consumers. Our study provides evidence that non‐native species can ameliorate some effects of environmental degradation, and we suggest that future research considers how the effects of non‐native species, either positive or negative, may vary across human‐modified landscapes.
Shallow snowpack inhibits soil respiration in sagebrush steppe through multiple biotic and abiotic mechanisms
Authors: Tucker Colin L. , Tamang Shanker , Pendall Elise , Ogle Kiona
Published: June 2016

In sagebrush steppe, snowpack may govern soil respiration through its effect on multiple abiotic and biotic factors. Across the Intermountain West of the United States, snowpack has been declining for decades and is projected to decline further over the next century, making the response of soil respiration to snowpack a potentially important factor in the ecosystem carbon cycle. In this study, we evaluated the direct and indirect roles of the snowpack in driving soil respiration in sagebrush steppe ecosystems by taking advantage of highway snowfences in Wyoming to manipulate snowpack. An important contribution of this study is the use of Bayesian modeling to quantify the effects of soil moisture and temperature on soil respiration across a wide range of conditions from frozen to hot and dry, while simultaneously accounting for biotic factors (e.g., vegetation cover, root density, and microbial biomass and substrate‐use diversity) affected by snowpack. Elevated snow depth increased soil temperature (in the winter) and moisture (winter and spring), and was associated with reduced vegetation cover and microbial biomass carbon. Soil respiration showed an exponential increase with temperature, with a temperature sensitivity that decreased with increasing seasonal temperature (Q10 = 4.3 [winter], 2.3 [spring], and 1.7 [summer]); frozen soils were associated with unrealisticQ10 ≈ 7989 due to the liquid‐to‐ice transition of soil water. Soil respiration was sensitive to soil water content; predicted respiration under very dry conditions was less than 10% of respiration under moist conditions. While higher vegetation cover increased soil respiration, this was not due to increased root density, and may reflect differences in litter inputs. Microbial substrate‐use diversity was negatively related to reference respiration (i.e., respiration rate at a reference temperature and optimal soil moisture), although the mechanism remains unclear. This study indicates that soil respiration is inhibited by shallow snowpack through multiple mechanisms; thus, future decreases in snowpack across the sagebrush steppe have the potential to reduce losses of soil C, potentially affecting regional carbon balance.
Greater impacts from an extreme cold spell on tropical than temperate butterflies in southern China
Authors: Wang Xu , Liu Hong , Gu Mao‐Bin , Boucek Ross , Wu Zhong‐Min , Zhou Guang‐Yi
Published: June 2016

The forecasted changes in global climate include not only shifts in average conditions, but also changes in the frequency and intensity of climatic extremes. One such climate extreme expected to change in the future are extreme cold spells. Although these disturbances may become less frequent, extreme cold spells are believed to persist in the foreseeable future and will likely have profound effects on species distributions, community organization, and ecosystem function. However, generalities about how ecosystems respond to these disturbances remain understudied. In 2008, an extreme once‐in‐50‐year cold spell affected sub‐tropical China, causing catastrophic damage to natural systems within the swath of the disturbance. In this study, we investigated the effects of this disturbance on a community of butterflies in the Nanling Mountain Preserve in southern China. Butterfly count surveys were conducted from 2006 to 2011. We predicted that the 2008 cold spell would have disproportionate effects on tropical butterfly species, increasing community dominance of more broadly tolerant temperate species. Over the course of the study, we counted 3403 butterflies from 249 species. Our results showed that the cold spell reduced abundances of temperate and tropical species by 50% and 88%, respectively. The disproportionate loss of tropical butterfly species changed butterfly community structure, resulting in a post cold spell community nearly completely dominated by temperate species. Butterfly communities remained dominated by temperate species for 2 years before the abundances of tropical species return to predisturbance conditions in 2011. As cold spells change in frequency and intensity in the future, we should expect their role in structuring sub‐tropical communities, in particular, the presence and dominance of tropical species to also change.
Design for mosquito abundance, diversity, and phenology sampling within the National Ecological Observatory Network
Authors: Hoekman D. , Springer Y. P. , Gibson C. , Barker C. M. , Barrera R. , Blackmore M. S. , Bradshaw W. E. , Foley D. H. , Ginsberg H. S. , Hayden M. H. , Holzapfel C. M. , Juliano S. A. , Kramer L. D. , LaDeau S. L. , Livdahl T. P. , Moore C. G. , Nasci R. S. , Reisen W. K. , Savage H. M.
Published: June 2016

The National Ecological Observatory Network (NEON) intends to monitor mosquito populations across its broad geographical range of sites because of their prevalence in food webs, sensitivity to abiotic factors, and relevance for human health. We describe the design of mosquito population sampling in the context ofNEON's long‐term continental scale monitoring program, emphasizing the sampling design schedule, priorities, and collection methods. Freely availableNEONdata and associated field and laboratory samples, will increase our understanding of how mosquito abundance, demography, diversity, and phenology are responding to land use and climate change.
An amphibian species of concern prefers breeding in active beaver ponds
Authors: Zero Victoria H. , Murphy Melanie A.
Published: June 2016

Changes in water availability threaten to reduce suitable habitat for wildlife in the western United States. Ecosystem engineers, such as beavers (Castor canadensis), potentially mitigate the effects of such habitat changes, particularly in stochastic environments. Our goal was to determine factors driving wetland use of a widespread, declining species, the northern leopard frog (Lithobates pipiens), in southeastern Wyoming. We evaluated hypotheses about habitat preferences of leopard frogs in a healthy population using occupancy modeling. Although leopard frogs may breed in a variety of wetlands, we found that the main drivers of breeding distribution in southeast Wyoming were the degree of beaver activity at wetlands and the ability of a site to retain water throughout the summer. In both years of our study (2012–2013), leopard frogs bred only in beaver ponds, with a preference for those ponds actively used by beavers. Leopard frogs also bred in wetlands that were less likely to dry over the course of the season. This effect was strongest in a dry year when water availability was limiting (2012), but still among the top drivers in the wetter year (2013). The decreased predictive power of water in a high snowpack year corresponded to an increase in the importance of wetland shape complexity, likely representative of breeding habitat availability along wetland edges. Identifying factors driving the distribution of healthy populations of species that are declining elsewhere can uncover limiting factors across the species’ range. We conclude that beavers are one vital conservation and management tool for maintaining declining populations of northern leopard frogs. While site‐level effects may vary, the presence of beaver ponds across the landscape in water‐limited systems, particularly in times of drought, should have positive impacts on many native amphibian species.
Avian relationships with wildfire at two dry forest locations with different historical fire regimes
Authors: Latif Quresh S. , Sanderlin Jamie S. , Saab Victoria A. , Block William M. , Dudley Jonathan G.
Published: June 2016

Wildfire is a key factor influencing bird community composition in western North American forests. We need to understand species and community responses to wildfire and how responses vary regionally to effectively manage dry conifer forests for maintaining biodiversity. We compared avian relationships with wildfire burn severity between two dry forest locations of Arizona and Idaho. We predicted different responses to wildfire between locations due to regional differences in historical fire regime. We conducted point count surveys for 3 yr following wildfire (Arizona: 1997–1999; Idaho: 2008–2010) and used multispecies hierarchical models to analyze relationships of bird occupancy with burn severity. Consistent with our prediction for mixed‐severity fire regimes characterizing the Idaho location, we observed proportionately more positive species occupancy relationships and, consequently, a positive species richness relationship with burn severity in Idaho. We also observed the opposite pattern in Arizona, which was congruent with our prediction for the low‐severity fire regime characterizing that location. Cavity nesters and aerial insectivores occupied more severely burned sites following wildfire, corresponding with predicted increases in nesting substrate and foraging opportunities for these species. In contrast, canopy‐nesting foliage gleaners and pine seed consumers exhibited negative relationships with burn severity. Our results were consistent with predictions based on species life histories and with patterns from the literature, suggesting generality of observed relationships and locational difference in relationships with wildfire. We therefore suggest that optimal management strategies for maintaining avian diversity could differ regionally. Specifically, intensive fuels management may be ecologically less appropriate for promoting biodiversity in areas such as the Idaho location where mixed‐severity wildfires and dense forest stands were historically more common.
Snake body size frequency distributions are robust to the description of novel species
Authors: Maritz Bryan , Kgaditse Mimmie , Alexander Graham John
Published: June 2016

The accurate interpretation of body size frequency distributions (BSFDs) has important implications for understanding large‐scale ecological and evolutionary patterns because they are shaped by ecological and evolutionary processes. However, incomplete species sampling, resulting either from a paucity of reliable body size data or because those species have not yet been detected/described, also has the potential to influence BSFD shape and skew when missing species are disproportionately large or small. Missing species may thus influence the skew of a BSFD, misleading subsequent interpretations. In contrast to many vertebrate taxa, the BSFDs of snakes appears to be log‐normal, with no significant skew. However, the influence of imperfect species sampling on these distributions has however not been previously evaluated. We collated body size data and date of description for 300 species of elapid, and 264 species of viperid snakes and assessed the shape and skew of the BSFD of each clade. Next we tested the hypothesis that date of description was related to body size in each clade. We show that the BSFDs of elapid and viperid snakes are both log‐normal, with no significant skew. Moreover we demonstrate size‐related differences in the probability of detection (as measured by year of description) among elapids and vipers: in both lineages, species with larger body size tend to have been described earlier. However, simulations testing the effect of the addition of novel, small‐bodied species revealed that the distributions of elapids and vipers are not highly vulnerable to becoming significantly skewed in the future. Our results support current interpretations of BSFDs in snakes that suggest a lack of size‐associated biases in the speciation and extinction rates of this clade.
Molecular Understanding of the Bulk Composition of Crystalline Nonstoichiometric Hydroxyapatites: Application to the Rationalization of Structure–Reactivity Relationships
Authors: Ben Osman Manel , Krafft Jean Marc , Millot Yannick , Averseng Frederic , Yoshioka Tetsuya , Kubo Jun , Costentin Guylène
Published: June 2016

Crystalline hydroxyapatite samples (HAps) have been prepared by using the co‐precipitation method under various pH conditions, leading to nonstoichiometric solids (1.65 < Ca/P < 1.77). The aim of this study was to rationalize the sensitivity of the catalytic activity of HAps to their bulk compositions going from the macroscopic level expressed by the Ca/P ratio to the molecular level properties of the bulk. From DRIFT, 31P NMR and Raman characterizations, hydroxyapatites were obtained with a range of structural defects compared with the ideal stoichiometric compound. If the amount of HPO42– and B‐type carbonates directly impacts the Ca/P ratio, it is not the case for A‐type carbonates. All these defects, and especially the A‐type carbonates, participate in the modulation of OH content inside the channels. Irrespective of the Ca/P values, the OH concentration appears to be perfectly related to the surface basic reactivity measured through 2‐methyl‐3‐butyn‐2‐ol (MBOH) conversion. Thus, except for the similar carbonate content (in cases of low Ca/P values), the Ca/P ratio is not sufficient to predict the catalytic behavior of all HAps synthesized under various conditions: in the case of variable carbonate content monitored under different pH conditions, a larger range of Ca/P ratio can be obtained including over‐stoichiometric HAps samples (Ca/P > 1.67), and the bulk OH concentration becomes a much better descriptor than the Ca/P ratio to account for the basic reactivity.
Site‐directed mutagenesis studies of hydrophobic residues in the lid region of T1 lipase
Authors: Tang Qingyun , Lan Dongming , Yang Bo , Khan Faez Iqbal , Wang Yonghua
Published: June 2016

T1 lipase is a potential biocatalyst for industrial application since it is highly thermostable and displays optimal activity at 60–75°C. Structural analysis of T1 lipase shows that its lid region undergoes a spatial displacement along with a distinct secondary structure reorganization upon activation. To study structure/function of this atypical lid, we performed site‐directed mutagenesis on the hydrophobic residues in the lid region. These residues were mutated to hydrophilic ones and biochemical properties of mutants were investigated. Results showed that F181 might be an important residue for enzyme‐substrate binding. Mutants A186S and A190S had 35–50% increase in catalytic efficiencies compared to wild‐type T1, without compromising their functions at high temperatures. In general, mutagenesis did not cause large changes to chain‐length preference in T1 lipase. Mutants A186S and V187N were inactive towards long‐chain pNP esters (p‐Nitrophenyl stearate) and V187N showed lower activity towards long‐chain triacylglycerols than wt T1, which makes it a potential catalyst in dairy industry. Thermostability of mutants were affected at different extent due to the influence of hydrophobic contact between the lid and the protein core. These findings not only shed light on the lipase structure/function relationship but also lay the framework for further engineering to gain more potent, stable, and selective lipases.

Practical applications: A thermostable T1 lipase owns an atypical lid and hydrophobic residues in the lid influence its catalytic properties. Here, we screened mutants A186S and A190S with 35–50% increase in catalytic efficiency, which have industrial application in the modification of fats and oils. Moreover, mutant V187N showed lower activity towards long‐chain TAGs than wt T1. This mutant can be a potential biocatalyst in dairy industry which promote generation of short‐chain fatty acids from milk fats to increase flavors in dairy products.

The lid region of thermostable T1 lipase undergoes a spatial displacement along with a distinct secondary structure reorganization upon activation (PDB ID: 2DSN, 2W22 [16,17]). Mutagenesis on hydrophobic residues in the lid affect catalytic properties of T1 lipase.