bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanisms influencing the coexistence of multiple consumers and multiple resources: resource and apparent competition
Authors: McPeek Mark A.
Published: July 2018

Interactions among multiple resources and consumers involve two indirect interactions: resource competition among consumers and apparent competition among resources. However, competition among multiple consumers is typically viewed through the lens of direct interactions embodied in the Lotka‐Volterra competition model, which fails to capture the mechanisms of these indirect interactions. In this paper, I analyze various elaborations of MacArthur's and Tilman's original consumer–resource models including more than two species per trophic level, saturating functional responses, and direct intraspecific density dependence within the consumers. First, the simplest model with two resources and two consumers with linear functional responses is analyzed via the structure of the resulting isoclines, and this is reconciled with Tilman's graphical ZNGI/consumption vector approach. With three species at each trophic level even in this simple model, each consumer is not required to have the largest impact on the resource that most limits its growth for multiple consumers to coexist. In fact, a consumer that is an inferior competitor on each resource in isolation may still coexist with superior competitors, and conversely a consumer that is an inferior competitor on each available resource may still be able to drive all other consumers extinct. However, the maximum number of coexisting consumers is set by the number of available resources. Saturating functional responses do not qualitatively alter the conditions for multiple consumers and resources to coexist at a stable point equilibrium but do increase the range of apparent competitive abilities for resources that can invade and coexist. Saturating functional responses also increase the range of dynamics that the community may display (i.e., limit cycles and chaos), which previous analyses have shown can permit more consumer species than resources to coexist. Adding direct intraspecific density dependence in the consumers, either in the form of feeding interference or density‐dependent demographic rates, permit more consumers to coexist than available resources, even at stable point equilibria. Understanding the indirect effects that cascade through a community is essential to predicting community changes and understanding how species at multiple trophic levels coexist, and these indirect effects should not be shrouded behind the curtain of Lotka‐Volterra competition.
Linking resource selection and step selection models for habitat preferences in animals
Authors: Michelot Théo , Blackwell Paul G. , Matthiopoulos Jason
Published: July 2018

The two dominant approaches for the analysis of species–habitat associations in animals have been shown to reach divergent conclusions. Models fitted from the viewpoint of an individual (step selection functions), once scaled up, do not agree with models fitted from a population viewpoint (resource selection functions [RSFs]). We explain this fundamental incompatibility, and propose a solution by introducing to the animal movement field a novel use for the well‐known family of Markov chain Monte Carlo (MCMC) algorithms. By design, the step selection rules of MCMC lead to a steady‐state distribution that coincides with a given underlying function: the target distribution. We therefore propose an analogy between the movements of an animal and the movements of an MCMC sampler, to guarantee convergence of the step selection rules to the parameters underlying the population's utilization distribution. We introduce a rejection‐free MCMC algorithm, the local Gibbs sampler, that better resembles real animal movement, and discuss the wide range of biological assumptions that it can accommodate. We illustrate our method with simulations on a known utilization distribution, and show theoretically and empirically that locations simulated from the local Gibbs sampler give rise to the correct RSF. Using simulated data, we demonstrate how this framework can be used to estimate resource selection and movement parameters.
Plant genotypic diversity interacts with predation risk to influence an insect herbivore across its ontogeny
Authors: Wetzel William C. , Aflitto Nicholas C. , Thaler Jennifer S.
Published: July 2018

A growing number of studies have manipulated intraspecific plant diversity and found dramatic changes in the densities of associated insect herbivores and their predators. While these studies have been essential for quantifying the net ecological consequences of intraspecific plant diversity, they have been less effective at uncovering the ways in which plant diversity alters trophic interactions within arthropod communities. We manipulated intraspecific plant diversity and predation risk in the field in a factorial design to reveal how a mixture of plant genotypes changes the response of an herbivorous beetle (Leptinotarsa decemlineata) to a common stink bug predator (Podisus maculiventris). We repeated the manipulations twice across the ontogeny of the beetle to examine how the effects of diversity on the predator–prey interaction differ between larval and adult stages. We found that intraspecific plant diversity, mixtures of susceptible and resistant varieties of potato (Solanum tuberosum), reduced larval survival by 20% and adult oviposition by 34%, which surprisingly put survival and oviposition lower in the mixed‐genotype plots than in the resistant monocultures. Moreover, we found that predation risk reduced larval survival 25% and 11% in resistant and susceptible monocultures, respectively, but had no effect in the mixture. This result indicated that our genotypic mixing treatment interacted nonadditively with predation risk such that plant diversity altered the predator–prey interaction by changing the responses of the beetles to their stink bug predators. In addition, even though predation risk reduced larval survival, it increased adult overwintering survival by 9%, independently of plant treatment, suggesting that these interactions change through ontogeny. A key implication of our study is that plant diversity influences arthropod communities not only by changing resource quality, as past studies have suggested, but also by changing interactions between species within the arthropod community.
Effects of altered dry season length and plant inputs on soluble soil carbon
Authors: Homyak Peter M. , Blankinship Joseph C. , Slessarev Eric W. , Schaeffer Sean M. , Manzoni Stefano , Schimel Joshua P.
Published: July 2018

Soil moisture controls microbial activity and soil carbon cycling. Because microbial activity decreases as soils dry, decomposition of soil organic matter (SOM) is thought to decrease with increasing drought length. Yet, microbial biomass and a pool of water‐extractable organic carbon (WEOC) can increase as soils dry, perhaps implying microbes may continue to break down SOM even if drought stressed. Here, we test the hypothesis that WEOC increases as soils dry because exoenzymes continue to break down litter, while their products accumulate because they cannot diffuse to microbes. To test this hypothesis, we manipulated field plots by cutting off litter inputs and by irrigating and excluding precipitation inputs to extend or shorten the length of the dry season. We expected that the longer the soils would remain dry, the more WEOC would accumulate in the presence of litter, whereas shortening the length of the dry season, or cutting off litter inputs, would reduce WEOC accumulation. Lastly, we incubated grass roots in the laboratory and measured the concentration of reducing sugars and potential hydrolytic enzyme activities, strictly to understand the mechanisms whereby exoenzymes break down litter over the dry season. As expected, extending dry season length increased WEOC concentrations by 30% above the 108 μg C/g measured in untreated plots, whereas keeping soils moist prevented WEOC from accumulating. Contrary to our hypothesis, excluding plant litter inputs actually increased WEOC concentrations by 40% above the 105 μg C/g measured in plots with plants. Reducing sugars did not accumulate in dry senesced roots in our laboratory incubation. Potential rates of reducing sugar production by hydrolytic enzymes ranged from 0.7 to 10 μmol·g−1·h−1 and far exceeded the rates of reducing sugar accumulation (~0.001 μmol·g−1·h−1). Our observations do not support the hypothesis that exoenzymes continue to break down litter to produce WEOC in dry soils. Instead, we develop the argument that physical processes are more likely to govern short‐term WEOC dynamics via slaking of microaggregates that stabilize SOM and through WEOC redistribution when soils wet up, as well as through less understood effects of drought on the soil mineral matrix.
Social norms are enforced by friends: The effect of relationship closeness on bystanders’ tendency to confront perpetrators of uncivil, immoral, and discriminatory behaviors
Authors: Moisuc Alexandrina , Brauer Markus
Published: July 2018

When witnessing an uncivil, immoral, or discriminatory behavior, bystanders have the opportunity to “speak up” and confront the perpetrator about his/her act. We examined whether the closeness of the relationship between the bystander and the perpetrator affects the bystander's reaction. We asked middle schoolers, high schoolers, and university students (N = 1,386) to indicate how they would react if they were to witness each of 26 uncivil, immoral, or discriminatory behaviors. We experimentally manipulated the relationship to the perpetrator, who was described as a friend, an acquaintance, or a stranger. Results showed that the closer the relationship to the perpetrator the greater the bystander's self‐reported likelihood of “speaking up.” The findings speak to the role of close relationships in the perpetuation of social norms. They also suggest ways to curb anti‐social behaviors in a variety of school and organizational settings.
Insight into thermal dissociation of tri‐n‐octylamine hydrochloride: The key to realizing CO2 mineralization with waste calcium/magnesium chloride liquids
Authors: Dong Chunhua , Song Xingfu , Zhang Jie , Meijer Evert Jan , Chen Hang , Yu Jianguo
Published: July 2018

A thermal dissociation process (ideally, 100% atom utilization) to regenerate the amine extractant and to produce gaseous HCl which is the key to realizing the CO2 mineralization with metal chloride waste liquids was investigated. Solvent effects on the thermal dissociation of tri‐n‐octylamine hydrochloride (TOAHCl) were predicted to be prominent via analyzing structure parameters, charge distribution, solvation free energy, apparent basicity, and N‐H frequency with the help of molecular simulation and experiments. Inert solvents with low polarity such as decalin, dodecane were favorable in thermal dissociation experiments. In particular, decalin enhanced the dissociation most effectively which is in agreement with the prediction. In dilute solutions, the thermal dissociation kinetics was shown to be first order. The apparent reaction rate (3.0 × 10−4−1.5 × 10−2 min−1) and activation energy (58.219‐121.827 kJ/mol) differ a lot at 180‐190°C in various solvents, confirming a strong solvent effect. A two‐stage reaction scheme in dilute solutions has been proposed from the experimental study. The overall process is entropically driven, with the removal of HCl into gas phase from the solvated state. The work could offer a fundamental direction for the further actual process.
Regime shifts in the multi‐annual evolution of a sandy beach profile
Authors: Kuriyama Yoshiaki , Yanagishima Shinichi
Published: July 2018

Extreme storms occasionally induce extraordinarily large morphological changes, which may have major impacts on coastal resilience, tourism and the environment. Some of the changes are persistent, and they are defined as regime shifts. During a 28‐year period from 1986 to 2014, the foreshore and the inner transition zone of the Hasaki coast of Japan underwent four morphological stages separated by regime shifts in beach profiles. From stage 2 to stages 3 and 4, over a relatively short period between 2006 and 2008, the beach profiles in the foreshore and the inner transition zone drastically changed, mainly because of large offshore waves. From stage 2 to stage 3, the foreshore and the inner transition zone were greatly eroded. Then, from stage 3 to stage 4, although the inner transition zone was further eroded, the foreshore underwent accretion. The severe erosion of the inner transition zone over the 2‐year period formed a steep slope, which was inferred to have led to accretion in the foreshore in stage 4. Stage 4 persisted for approximately 7 years, and the beach profile had not returned to a similar morphology to those of stages 1 or 2 by the end of the study period. © 2018 John Wiley & Sons, Ltd.
Rwandan stakeholder perspectives of integrated family planning and HIV services
Authors: Wall Kristin M. , Bayingana Roger , Ingabire Rosine , Ahlschlager Lauren , Tichacek Amanda , Allen Susan , Karita Etienne
Published: July 2018

The purpose of this qualitative study was to understand the knowledge, attitudes, and practices among key Rwandan policymakers and stakeholders related to family planning (FP) and integrated HIV/FP services. Motivational in‐depth interview format and content was developed after an extensive policy review. A convenience sample of 10 high‐level HIV and FP Rwandan policymakers and stakeholders completed the interview. Stakeholders demonstrated strong foundational knowledge of HIV and FP. Given the choice, stakeholders would allocate more monies to FP and less to HIV than currently distributed. Respondents felt that improved FP method knowledge, especially long‐acting reversible contraception, among clients/couples and providers, was needed to address myths, misconceptions, and biases. The most often cited way to integrate HIV/FP services was development of integrated tools (eg, training materials, data collection tools, and advocacy and policy guidance). We recommend strategies for policy advancement supportive of HIV/FP service integration inclusive of couples and long‐acting reversible contraception methods.
Spatio‐temporal aspects of snowpack runoff formation during rain on snow
Authors: Würzer Sebastian , Jonas Tobias
Published: July 2018

Rain on snow (ROS) is a complex phenomenon leading to repeated flooding in many regions with a seasonal snow cover. The potential to generate floods during ROS depends not only on the magnitude of rainfall but also on the areal extent of the antecedent snow cover and the spatio‐temporal interaction between meteorologic and snowpack properties. The complex interaction of these factors makes it difficult to accurately predict the effect of snow cover on runoff formation for an upcoming ROS event. In this study, the detailed physics‐based snow cover model SNOWPACK was used to assess the influence of snow cover properties on converting rain input to available snowpack runoff during 191 ROS events for 58 catchments in the Swiss Alps. Conditions identified by the simulations that led to excessive snowpack runoff were a large snow‐covered fraction, spatially homogeneous snowpack properties, prolonged rainfall events, and a strong rise in air temperature over the course of the event. These factors entail a higher probability of snowpack runoff occurring synchronously within the catchment, which in turn favours higher overall runoff rates. The findings suggest that during autumn and late spring, flooding due to ROS is more likely to happen, whereas during winter a coincidence of the above conditions in the study area is quite rare. For example, an autumn event which occurred in October 2011 resulted from a combination of spatially homogeneous snowpack conditions following a recent snowfall and high, but not exceptional rainfall, and led to major flooding. The results of this study provide key factors to assess in advance of an incoming ROS event and emphasize the importance of detailed snow monitoring for flood forecasting in snow‐affected watersheds.
Associations between household air pollution and reduced lung function in women and children in rural southern India
Authors: Patel Sameer , Leavey Anna , Sheshadri Ajay , Kumar Praveen , Kandikuppa Sandeep , Tarsi Jaime , Mukhopadhyay Krishnendu , Johnson Priscilla , Balakrishnan Kalpana , Schechtman Kenneth B. , Castro Mario , Yadama Gautam , Biswas Pratim
Published: July 2018

Half of the world's population still relies on solid fuels to fulfill its energy needs for cooking and space heating, leading to high levels of household air pollution (HAP), adversely affecting human health and the environment. A cross‐sectional cohort study was conducted to investigate any associations between: (1) HAP metrics (mass concentration of particulate matter of aerodynamic size less than 2.5 μm (PM2.5), lung‐deposited surface area (LDSA) and carbon monoxide (CO)); (2) a range of household and socio‐demographic characteristics; and (3) lung function for women and children exposed daily to biomass cookstove emissions, in rural southern India. HAP measurements were collected inside the kitchen of 96 households, and pulmonary function tests were performed for the women and child in each enrolled household. Detailed questionnaires captured household characteristics, health histories and various socio‐demographic parameters. Simple linear and logistic regression analysis was performed to examine possible associations between the HAP metrics, lung function and all household/socio‐demographic variables. Obstructive lung defects (forced vital capacity (FVC) ≥ lower limit of normal (LLN) and forced expiratory volume in 1 second (FEV1)/FVC < LLN) were found in 8% of mothers and 9% of children, and restrictive defects (FVC < LLN and FEV1/FVC ≥ LLN) were found in 17% of mothers and 15% of children. A positive association between LDSA, included for the first time in this type of epidemiological study, and lung function was observed, indicating LDSA is a superior metric compared to PM2.5 to assess effects of PM on lung function. HAP demonstrated a moderate association with subnormal lung function in children. The results emphasize the need to look beyond mass‐based PM metrics to assess fully the association between HAP and lung function.
Determination of phosphatidylethanol 16:0/18:1 in whole blood by 96‐well supported liquid extraction and UHPLC‐MS/MS
Authors: Berg Thomas , Eliassen Elin , Jørgenrud Benedicte , Kabashi Saranda , Petukhov Alexey , Bogstrand Stig Tore
Published: July 2018

Background

Phosphatidylethanols (PEths) are specific, direct alcohol biomarkers that can be determined in human blood to distinguish between heavy and social drinking. PEth 16:0/18:1 is among the most predominant PEth homologues in human blood. The aim of the study was to develop a high throughput and sensitive UHPLC‐MS/MS method for the determination of PEth 16:0/18:1 in whole blood.

Methods

Whole blood samples were prepared by 96‐well supported liquid extraction (SLE). Extracted samples were analyzed for PEth 16:0/18:1 by reversed phase UHPLC‐MS/MS.

Results

The developed UHPLC‐MS/MS method was fully validated in whole blood with PEth 16:0/18:1‐D5 as internal standard. Intermediate precision and intermediate accuracy were within ≤± 12% and ≤± 17%, respectively, at PEth 16:0/18:1 concentrations of 1.4‐2112 ng/mL (2.0‐3004 nmol/L). Limit of quantification (LOQ) was 1.7 ng/mL (2.4 nmol/L).

Conclusion

For the first time, 96‐well SLE was used for preparation of a PEth homologue in biological samples. A mixture of tert‐butyl methyl ether and 2‐propanol (5:1, v:v) was chosen as organic eluent based on an evaluation of extraction recovery, purity of extracts, and evaporation time. The developed UHPLC‐MS/MS method can be used for high throughput analyses and sensitive determinations of PEth 16:0/18:1 in whole blood.
Biochemical and structural characterization of 3‐ketosteroid‐Δ1‐dehydrogenase, a candidate enzyme for efficient bioconversion of steroids
Authors: Mao Shuhong , Guo Qianqian , Xu Panpan , Gao Dengke , Cheng Xiaotao , Zhu Menglu , Sun Dengyue , Zhu Zhangliang , Lu Fuping , Qin Hui‐Min
Published: July 2018

Background

3‐ketosteroid‐Δ1‐dehydrogenase, a key enzyme involved in microbial catabolism of sterols, catalyzes the 1, 2‐desaturation of steroidal substrates using FAD as a cofactor. Recombinant 3‐ketosteroid‐Δ1‐dehydrogenase from Arthrobacter simplex (KsdD4) was expressed in Escherichia coli BL21 (DE3).

Results

KsdD4 exhibited optimal activity at pH 7.0 and 35°C. KsdD4 had the highest activity toward 4‐androstene‐3,17‐dione (AD) and a moderate activity toward cortisone acetate and hydrocortisone. Structure‐based homology modeling revealed that Y118, Y355, Y528 and G532 are located in the active site, thus the most likely catalytic residues. The substrate‐binding cavity was composed of hydrophobic residues with small side chains, including A49, V328, A390 and A531, which facilitate the recognition of steroidal substrates with large C17 side‐chains. E332 forms a unique hydrogen bond with substrates. Recombinant E. coli resting cells expressing KsdD4 showed high catalytic activity in the presence of various organic solvents. A fed‐batch bioconversion using resting cells resulted in efficient production of 2.66 g L−1 androst‐1,4‐diene‐3,17‐dione (ADD).

Conclusion

Biochemical data and structural analysis greatly advanced our understanding of the KsdD family enzymes, and the fed‐batch strategy improved the bioconversion of steroids. © 2018 Society of Chemical Industry
Production and optimization of isopropyl palmitate via biocatalytic route using home‐made enzymatic catalysts
Authors: Barsé Laísa Q , Graebin Natália G , Cipolatti Eliane P , Robert Julia M , Pinto Martina CC , Pinto Jose CCS , Freire Denise MG , Rodrigues Rafael C
Published: July 2018

BACKGROUND

This study investigated the use of core–shell biocatalysts, synthesized using recombinant lipase B from Candida antarctica (CALB), for the production of isopropyl palmitate and the optimization of this biocatalytic route.

RESULTS

Initially, three distinct core–shell biocatalysts, were evaluated for the production of isopropyl palmitate and the CALB‐P(S‐co‐DVB)/P(S‐co‐DVB) biocatalyst (biocatalyst made of polystyrene‐co‐divinylbenzene core–shell particles) was the most suitable biocatalyst for this purpose. The effect of organic solvents – n‐hexane, isooctane, n‐heptane and cyclohexane – in the ester conversion was evaluated, and the most suitable solvent was the isooctane. The optimal reaction conditions were pursued conducting an optimization statistical analysis. The most suitable reaction conditions were identified: reaction temperature, 55°C; substrate molar ratio, 1:1.42 (palmitic acid: isopropyl alcohol); biocatalyst content, 24% w/w. Finally, the reuse of the biocatalyst was evaluated and the relative enzymatic activity remained up to 50% after the fourth cycle.

CONCLUSION

Results were compared with commercial biocatalyst and the home‐made enzymatic biocatalyst (CALB‐P(S‐co‐DVB/PS‐co‐DVB) showed promise for application in the synthesis of isopropyl palmitate. The optimization study improved reaction conversion from 30% to 78%. The home‐made biocatalysts exhibited better performance for the synthesis of isopropyl palmitate compared with the commercial Novozym 435, using the same enzymatic activity. © 2018 Society of Chemical Industry
Fabrication of a SGO/PVDF‐g‐PSSA composite proton‐exchange membrane and its enhanced performance in microbial fuel cells
Authors: Li Chen , Wang Lei , Wang Xudong , Li Cuicui , Xu Qibin , Li Guangyuan
Published: July 2018

BACKGROUND

Proton‐exchange membrane (PEM) has a significant effect on the performance and overall cost of microbial fuel cells (MFCs). In this study, a novel composite PEM is fabricated by compositing sulfonated graphene oxide (SGO) with the Poly(vinylidene fluoride)‐g‐Poly(styrene sulfonic acid) (PVDF‐g‐PSSA) copolymer. The performance of MFCs with these newly prepared composite PEMs as separators was evaluated. A Quartz crystal microbalance with dissipation (QCM‐D) combined with membrane‐coated sensor crystals was used to investigate the biofouling mechanism of PEMs in MFCs at a micro‐perspective.

RESULTS

The successful sulfonation of GO was confirmed by Fourier transform infrared spectrometry and X‐ray photoelectron spectroscopy. When the SGO loading was 1.0 wt%, the SGO/PVDF‐g‐PSSA membrane had higher water uptake (32.56%), proton conductivity (0.083 S cm−1) and excellent hydrophilicity (contact angle 70.78°) than that of Nafion 117. QCM‐D results further confirmed its better anti‐fouling property vs that of the PVDF‐g‐PSSA, GO/PVDF‐g‐PSSA, and Nafion 117 membranes. Moreover, the MFC working with the SGO/PVDF‐g‐PSSA membrane exhibited the highest maximum power density and best stability of power production after 3 months of operation.

CONCLUSION

The SGO/PVDF‐g‐PSSA‐1.0 composite PEM can be used as an alternative material to Nafion in MFCs and is conducive to the long‐term stable operation of MFCs. © 2018 Society of Chemical Industry
Design, Synthesis, and Molecular Modeling of Asymmetric Tolterodine Derivatives as Anticancer Agents
Authors: Dakarapu Veera venkatarao , Allaka Tejeswara Rao , Uppalla Lav Kumar , Jha Anjali
Published: July 2018

An efficient and short enantioselective synthesis of (S)‐ and (R)‐tolterodine acid isomers (7a–7i) was performed a 6‐methyl‐4‐phenylchroman‐2‐one intermediate from inexpensive and commercially available starting materials. A series of tolterodine acid hybrids 7 were synthesized and characterized by infrared, 1H NMR, 13C NMR, X‐ray diffraction, and mass spectral analysis followed by anticancer activity on human cancer cell lines including A549 and SKNSH. Our results revealed the final compounds exhibited moderate to potent activity against A549 and SKNSH. Compounds 7g and 7f were more cytotoxic than cisplatin against all tested two human cancer cell lines, with half maximal inhibitory concentration values of 13.2, 14.3, and 8.5 μM, respectively. In the present investigation, possible binding interaction of the target compounds with 3IVX protein, ligand conformations, including hydrogen bonds and the bond lengths, was analyzed. AutoDock 4.2 chemokine receptor has been investigated by molecular docking and was used to predict the affinity, activity, and binding orientation of ligand with the target protein and to analyze best conformations. Compound 7h exhibited more binding energy (ΔG = −5.52 kcal/mol) and dissociation constant (KI = 89.8 μM) with amino acids Glu 17 and Thr 87 interacting. Further studies are warranted to fully evaluate the analogues as the potential prodrugs with improved physiochemical properties.
Solar radiation measurements in the United States between 1916 and 1949 document widespread brightening in the mid‐20th century
Authors: Stanhill Gerald , Paudel Indira , Rosa Rafael
Published: July 2018

An analysis is presented of global radiation E
g↓ measurements made between 1916 and 1949 at 26 sites in the continental United States. The procedures used to fill gaps in the database are described and the accuracy of the data assessed. During this period E
g↓ averaged 172 and 41 W/m2 above the model‐estimated values for the same sites during the 1960–1990 period and 7 W/m2 below the average values estimated between 1991 and 2010; the largest changes were found at two urban sites, New York City and Pittsburgh. The major inter‐annual variation found within the 1916–1949 period was a significant spike lasting a decade which reached a maximum around 1940. This episode of global brightening was attributed to reduced emissions of anthropogenic aerosols during the economic depression together with lesser cloud cover associated with the severe droughts occurring in the same decade. The widespread global brightening which occurred concurrently outside the United States is documented and a link between global brightening and global warming during the first half of the 20th century demonstrated.
Proactive Vitality Management and Creative Work Performance: The Role of Self‐Insight and Social Support
Authors: Op den Kamp Emma M. , Bakker Arnold B. , Tims Maria , Demerouti Evangelia
Published: July 2018

Integrating proactivity and creativity literatures, we argue that people can perform more creatively at work when they proactively manage their levels of vitality. Proactive vitality management is defined as individual, goal‐oriented behavior aimed at managing physical and mental energy to promote optimal functioning at work. We hypothesize that this process may be facilitated by being aware of one's own state and by support from others. A total of 242 employees participated in a weekly diary study for three consecutive weeks, yielding 610 observations. Results of multilevel analyses show that participants reported more creative work performance during weeks in which they had proactively used vitality management. In addition, in line with our predictions, self‐insight and social support for creativity in the workplace acted as cross‐level moderators and strengthened the relationship between proactive vitality management and creativity. We conclude that a proactive approach regarding physical and mental energy is an important bottom‐up strategy that may foster creativity in work settings.
Sprifermin treatment enhances cartilage integration in an in vitro repair model
Authors: Sennett Mackenzie L. , Meloni Gregory R. , Farran Alexandra J. E. , Guehring Hans , Mauck Robert L. , Dodge George R.
Published: July 2018

Cartilage integration remains a clinical challenge for treatment of focal articular defects. Cartilage exhibits limited healing capacity that declines with tissue maturation. Many approaches have been investigated for their ability to stimulate healing of mature cartilage or integration of repair tissue or tissue‐engineered constructs with native cartilage. Growth factors present in immature tissue may enhance chondrogenesis and promote integrative repair of cartilage defects. In this study, we assessed the role of one such factor, fibroblast growth factor 18 (FGF18). Studies using FGF18 have shown a variety of positive effects on cartilage, including stimulation of chondrocyte proliferation, matrix biosynthesis, and suppression of proteinase activity. To explore the role of FGF18 on cartilage defect repair, we hypothesized that treatment with recombinant human FGF18 (sprifermin) would increase matrix synthesis in a defect model, thus improving integration strength. To test this hypothesis, 6 mm cartilage cylinders were harvested from juvenile bovine knees. A central 3 mm defect was created in each explant, and this core was removed and replaced. Resulting constructs were cultured in control or sprifermin‐containing medium (weekly 24‐h exposure of 100 ng/ml sprifermin) for 4 weeks. Mechanical testing, biochemical analysis, micro‐CT, scanning electron microscopy, and histology were used to assess matrix production, adhesive strength, and structural properties of the cartilage‐cartilage interface. Results showed greater adhesive strength, increased collagen content, and larger contact areas between core and annular cartilage in the sprifermin‐treated group. These findings present a novel treatment for cartilage injuries that have potential to enhance defect healing and lateral cartilage–cartilage integration. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2648–2656, 2018.
Preharvest zinc sulfate spray improves the storability of longan (Dimocarpus longan Lour.) fruits by protecting the cell wall components and antioxidants of pericarp
Authors: Luo Tao , Niu Jiajia , Guo Xiaomeng , Wu Huitao , Han Dongmei , Shuai Liang , Wu Zhenxian
Published: July 2018

BACKGROUND

Zinc (Zn) fertilization has been reported to improve the quality and storability of many fruits, but the mechanism had not been systematically studied. In this study, the effect of preharvest 0.2% zinc sulfate (ZnSO4) spray on the storability of longan fruits was investigated.

RESULTS

The preharvest ZnSO4 spray did not significantly influence the quality but increased the Zn content in longan pericarp by 12.5‐fold. More importantly, the treatment significantly reduced the rotting rate, pericarp browning, and aril breakdown of longan fruits stored at room temperature and low temperature. Physiological and biochemical results indicated that the treatment resulted in higher water retention capacity and inhibited the degradation of cellulose, pectin, flavonoid, and phenolics of longan pericarp at the late stages of storage. Consistent with these results, the activity of cellulase, polygalacturonase, polyphenol oxidase, and lipoxygenase was significantly inhibited in the ZnSO4‐treated longan pericarp at the late stages of storage.

CONCLUSION

Higher Zn content in the ZnSO4‐treated longan pericarp might help to enhance the resistance against microbial infection, inhibit the hydrolysis of cell wall components, and thus effectively protected the cell wall components, maintained the cellular compartmentation, and prevented the phenolics and flavonoid from degradation by browning‐related enzymes. © 2018 Society of Chemical Industry
On‐vine withering process of ‘Moscato bianco’ grapes: effect of cane‐cut system on volatile composition
Authors: Giacosa Simone , Giordano Manuela , Vilanova Mar , Cagnasso Enzo , Río Segade Susana , Rolle Luca
Published: July 2018

BACKGROUND

Cane‐cut on‐vine withering is a grape dehydration technique used for dry and sweet wine production. The aim of this work was to study the influence of the cane‐cut technique applied at harvest to Moscato bianco grapes during the on‐vine withering process to produce dehydrated berries with a different chemical composition and a volatile profile.

RESULTS

After 24 days of dehydration, an on‐vine withering system using the cane‐cut technique induced an increase in the total volatile content compared with grapes produced with a normal on‐vine withering process. This increase was greater in glycosidically bound volatile compounds than in the free fraction. Bound linalool showed a significant increase of 52% when the cane‐cut withering system was applied but the grapes that were normally withered appeared to be less prone to the loss of free linalool. A significant increase in the glycosylated forms of nerol and geraniol was also observed in the two on‐vine withering systems on the 24th day compared with the control (fresh grapes at harvest date).

CONCLUSION

A cane‐cut, on‐vine withering system applied at harvest induced changes in the volatile composition of Moscato bianco grapes increasing total volatile content, consisting mainly of bound compounds, by the 24th day of dehydration. The grapes dehydrated on‐vine using this new system also showed significantly greater content of most of the free volatile compounds detected. © 2018 Society of Chemical Industry
Self‐Assembling PCL‐Based Nanoparticles as PTX Solubility Enhancer Excipients
Authors: Capasso Palmiero Umberto , Morosi Lavinia , Lupi Monica , Ponzo Marianna , Frapolli Roberta , Zucchetti Massimo , Ubezio Paolo , Morbidelli Massimo , D'Incalci Maurizio , Bello Ezia , Moscatelli Davide
Published: July 2018

The advent of nanotechnology in medicine has allowed to eliminate the toxic excipients that are often necessary to formulate lipophilic drugs in clinics. An example is paclitaxel, one of the most important chemotherapeutic drugs developed so far, where the Cremophor EL has been eliminated in the Genexol and Abraxane formulations. However, the complex procedures to synthesize these formulations hamper their cost‐effective use and, in turn, their distribution among the patient population. For this reason, a simplified method to formulate this drug directly at the bed of the patient has been adopted. It requires only the use of a syringe and it starts from a native dry amphiphilic biodegradable and biocompatible block‐copolymer obtained via the combination of the reversible addition–fragmentation chain transfer polymerization and ring‐opening polymerization. In this way, a novel paclitaxel formulation with the same drug pharmacological properties, but without the use of the Cremophor EL, can be produced. In addition, as long as these nanoparticles are engineered to act as solubility enhancers, a lower burden for its approval from the pharmaceutical regulatory agencies is also expected.
Using exome sequencing to decipher family history in a healthy individual: Comparison of pathogenic and population MTM1 variants
Authors: Penon Monica , Zahed Hengameh , Berger Victoria , Su Irene , Shieh Joseph T.
Published: July 2018

Background

When a family encounters the loss of a child early in life, extensive genetic testing of the affected neonate is sometimes not performed or not possible. However, the increasing availability of genomic sequencing may allow for direct application to families in cases where there is a condition inherited from parental gene(s). When neonatal testing is not possible, it is feasible to perform family testing as long as there is optimal interpretation of the genomic information. Here, we present an example of a healthy adult woman with a history of recurrent male neonatal losses due to severe respiratory distress who presented to Medical Genetics for evaluation. A family history of additional male neonatal loss was present, suggesting a potential inherited genetic etiology.

Methods

Although there was no DNA available from the neonates, by performing exome sequencing on the healthy adult woman, we found a missense variant in MTM1 as a potential candidate, which was deemed pathogenic based on multiple criteria including past report.

Results

By performing an analysis of all known MTM1‐disease associated mutations and control population variation, we can also better infer the effects of missense variations on MTM1, as not all variants are truncating. MTM1‐X‐linked myotubular myopathy is a condition that leads to male perinatal respiratory failure and a high risk for early mortality.

Conclusions

The application of genetic testing in the healthy population here highlights the broader utility of genomic sequencing in evaluating unexplained recurrent neonatal loss, especially when genetic testing is not available on the affected neonates.
Fractional conformable attractors with low fractality
Authors: Morales‐Delgado V. F. , Gómez‐Aguilar J. F. , Escobar‐Jiménez R. F.
Published: July 2018

In this paper, we considered a fractional conformable derivative of Liouville‐Caputo type of fractional‐order α=n−ϵ, which contains a small perturbation ϵ and positive integer n values between [0;1] to obtain the solutions of three different fractional conformable attractors (Chen's attractor, Genesio‐Tesi's attractor, and Liu's attractor). The fractional conformable Adomian decomposition method is applied to obtain an expansion of the fractional conformable derivative in ϵ=n−α. The solutions of the fractional chaotic systems are calculated in the form of convergent series. We investigate the dynamics of these attractors by numerical simulations for different fractional orders values and parameter ϵ.
Response of circular tunnel with imperfect interface bonding in layered ground subjected to obliquely incident plane P or SV wave
Authors: Zou Yan , Liu Huabei , Jing Liping , Miao Yu
Published: July 2018

A semianalytical procedure is proposed for evaluating the internal forces of circular tunnel with imperfect interface bonding in layered ground subjected to an obliquely incident plane P or SV wave. In this study, the hoop bending moment and hoop axial force are related to the free‐field responses of the ground. A one‐dimensional numerical approach is firstly presented to obtain the free‐field responses of a layered half‐space with an obliquely incident plane P or SV wave propagation. Then, the free‐field stress state is transformed and decomposed in the polar coordinate system. The internal forces of tunnel caused by the isotropic stress state and the pure shear state are calculated and then summed up to obtain the overall analytical solutions. Finally, the validity of the proposed semianalytical procedure is demonstrated by numerical examples.
Local refinement of flat‐top partition of unity based high‐order approximation
Authors: Liu Xiaoying , Zhao Zhiye , An Xinmei , Jiao Yuyong
Published: July 2018

The high‐order approximation with regularly patterned flat‐top partition of unity mesh in one‐ and two‐dimensional cases has been proven linearly independent. However, for problems with stress concentration or stress singularity, local refinement within the regular mesh is necessary to improve the accuracy and efficiency. This paper introduces local refinement of flat‐top partition of unity mesh within the framework of high‐order approximation in one‐ and two‐dimensional spaces, respectively. Based on the traditional PU mesh, the construction of locally refined flat‐top PU mesh is straightforward. With the rank deficiency counting approach, linear independence is proven from element level for the locally refined mesh system. Based on the numerical solution procedure presented, two numerical examples are analyzed to verify the proposed approximation method.
Genome Mining‐Mediated Discovery of a New Avermipeptin Analogue in Streptomyces actuosus ATCC 25421
Authors: Liu Weiying , Sun Fengxian , Hu Yang
Published: July 2018

Streptomyces actuosus ATCC 25421 was famous for producing thiopeptide nosiheptide, which has widely been used as a feed additive for the promotion of animal growth. Herein, we report the complete genome sequence of S. actuosus ATCC 25421, which consists of an 8,145,579‐bp circular chromosome with a G+C content of 72.53 % containing 7 536 protein‐coding genes. The antiSMASH 3.0 program was used to identify 49 biosynthetic gene clusters for putative secondary metabolites, including a putative lantipeptide gene cluster that showed 85 % similarity to the reported informatipeptin biosynthetic gene cluster, indicating that the putative lantipeptide gene cluster has the ability to generate the informatipeptin analogue. Compared with avermipeptin, the lantipeptide precursor peptide (termed avermipeptin B) from S. actuosus ATCC 25421 contains a 14‐aa leader peptide and a 24‐aa core peptide, in which Ile15 was different from Val15 in avermipeptin. We also deduced the structure and the biosynthetic mechanism of avermipeptin B. Heterologous expression of the avermipeptin B biosynthetic gene cluster in S. lividans TK24 was characterized by high‐resolution mass spectrometry (ESI‐MS/MS). Finally, we found that avermipeptin B displayed strong activity against Gram‐positive strains. The genome sequence reported here can encourage us to mine novel secondary metabolites and investigate their biosynthetic mechanism in the future.
Synthesis of a polyaspartic acid/4‐(2‐aminoethyl) morpholine graft copolymer and evaluation of its scale and corrosion inhibition performance
Authors: Shi Shuchen , Li Dongyi , Chai Chunxiao , Wu Yufeng , Xu Ying
Published: July 2018

A novel modified polyaspartic acid polymer, polyaspartic acid/4‐(2‐aminoethyl) morpholine graft copolymer (PASP/AEM), was prepared through a ring‐opening reaction of polysuccinimide and 4‐(2‐aminoethyl) morpholine and characterized by 1H NMR. The scale inhibition performance of this copolymer and its ability to disperse Fe2O3 were investigated in static tests. Scanning electron microscopy and X‐ray powder diffraction were used to analyze the effects of PASP/AEM on scale formation. The performance and mechanism of corrosion inhibition by the synthesized copolymer were studied via weight loss measurements and electrochemical measurements. The results showed that PASP/AEM possessed outstanding scale and corrosion inhibition efficiencies and had potential for use as a green scale and pickling inhibitor.
A model of identity grounded in the acute season of survivorship
Authors: Thiessen Maclean , Hack Thomas F. , Pitz Marshall , Anderson Marcia
Published: July 2018

Objective

Survivorship literature generally focuses on the cancer experience after diagnosis and treatment. However, acute survivorship, beginning with diagnosis and ending at the completion of treatment, has a lasting impact on the well‐being of patients. The purpose of this study was to generate a theoretical understanding of how identity is affected during acute survivorship.

Methods

Using grounded theory and interviews with patients, their families, and their friends, the impact of the acute survivorship phase on the identity of patients was explored in Manitoba, Canada. Forty‐two interviews were carried out, involving 18 patients with early malignancies and 15 friends and family members.

Results

The theory which evolved suggests that identity can be viewed as a construct of 3 concepts: values, social domains, and routine. Following diagnosis identity is disrupted as patients face challenges integrating the health care recipient social domain into their established routine. Patients indicated that the impact of the cancer diagnosis on their identities could have been minimized through earlier provision of the necessary information to re‐establish routine.

Conclusions

The theory that emerged from this study articulates the impact of the early cancer experience on the identity of patients. It also provides a framework for predicting which interventions may improve the cancer experience. Exploring how to best provide information that helps patients re‐establish and maintain their routines after diagnosis is an important future direction.
Phosphite alters the behavioral response of potato tuber moth (Phthorimaea operculella) to field‐grown potato
Authors: Mulugeta Tewodros , Mulatu Bayeh , Tekie Habte , Yesuf Mohammed , Andreasson Erik , Alexandersson Erik
Published: July 2018

BACKGROUND

The potato tuber moth (PTM) (Phthorimaea operculella) is a pest of solanaceous species that causes serious damage to potato tubers and tomato fruits. Control is mainly dependent on the use of synthetic chemicals, which pose a risk to the environment and health of farmers, especially in developing countries where application safety rules are often neglected. In this study we aimed at investigating the effects of a plant resistance inducer (PRI) potassium phosphite on PTM larval population density and PTM parasitoid levels, which can be used as biocontrol agents. We also tested whether intercropping with tomato, which is less attractive to PTM, provided a spatial border to further reduce PTM numbers.

RESULTS

In two different locations over two seasons, we showed that foliar application of phosphite more than halved the PTM larval populations on potato, and that PTM parasitoid numbers were unaffected. No consistent reduction in PTM was achieved by intercropping potato with tomato.

CONCLUSIONS

Phosphite reduced PTM numbers in the field without interfering with autochthonous parasitoids, indicating its suitability as part of an Integrated Pest Management strategy. Ex situ choice tests showed that phosphite‐treated potato deterred PTM, which could be a reason for the control of PTM in the field. © 2018 Society of Chemical Industry