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1.
Food Chem Toxicol ; 189: 114727, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38735359

RESUMEN

Published studies on the glycosylation, absorption, distribution, metabolism, excretion, and safety outcomes of orally ingested recombinant human lactoferrin (rhLF) were reviewed in the context of unanswered safety questions, including alloimmunization, allergenicity, and immunotoxicity potential of rhLF during repeated exposure. The primary objective was to summarize current safety data of rhLF produced in transgenic host expression systems. Overall, results from animal and human studies showed that rhLF was well tolerated and safe. Animal data showed no significant toxicity-related outcomes among any safety or tolerability endpoints. The no observed adverse effect levels (NOAEL) were at the highest level tested in both iron-desaturated and -saturated forms of rhLF. Although one study reported outcomes of rhLF on immune parameters, no animal studies directly assessed immunogenicity or immunotoxicity from a safety perspective. Data from human studies were primarily reported as adverse events (AE). They showed no or fewer rhLF-related AE compared to control and no evidence of toxicity, dose-limiting toxicities, or changes in iron status in various subpopulations. However, no human studies evaluated the immunomodulatory potential of rhLF as a measure of safety. Following this review, a roadmap outlining preclinical and clinical studies with relevant safety endpoints was developed to address the unanswered safety questions.

2.
Int J Toxicol ; : 10915818241247013, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38647416

RESUMEN

The oral toxicity of recombinant human lactoferrin (rhLF, Helaina rhLF, Effera™) produced in Komagataella phaffii was investigated in adult Sprague Dawley rats by once daily oral gavage for 14 consecutive days. The study used groups of 3-6 rats/sex/dose. The vehicle control group received sodium citrate buffer, and the test groups received daily doses of 200, 1000, and 2000 mg of rhLF in sodium citrate buffer per kg body weight. Bovine LF at 2000 mg/kg body weight per day was used as a comparative control. Clinical observations, body weight, hematology, clinical chemistry, iron parameters, immunophenotyping, and gross examination at necropsy were used as criteria for detecting the effects of treatment in all groups and to help select dose levels for future toxicology studies. Quantitative LF levels were also analyzed as an indication of bioavailability. Overall, administration of Helaina rhLF by once daily oral gavage for 14 days was well tolerated in rats at levels up to 2000 mg/kg/day, or 57 × Helaina's intended commercial use in adults, and indicating that a high dose of 2000 mg/kg/day is appropriate for future definitive toxicology studies.

3.
Am Surg ; 89(9): 3922-3923, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37191979

RESUMEN

Hepatic artery aneurysms (HAAs) are an uncommon clinical condition. Ruptured hepatic artery aneurysm carries a high incidence of mortality. Traditionally, they are treated with open surgical resection; however, endovascular aneurysm exclusion is an alternative option to open repair in select patients who have suitable anatomy. Here, we present a case of a giant hepatic artery aneurysm treated with a covered stent placement.


Asunto(s)
Aneurisma de la Aorta Abdominal , Implantación de Prótesis Vascular , Procedimientos Endovasculares , Humanos , Aneurisma de la Aorta Abdominal/cirugía , Arteria Hepática/cirugía , Resultado del Tratamiento , Stents
4.
Health Sciences Journal ; : 57-65, 2023.
Artículo en Inglés | WPRIM (Pacífico Occidental) | ID: wpr-984424

RESUMEN

INTRODUCTION@#The landscape of work has changed since the start of the COVID-19 pandemic as more companies shifted from face-to-face to the work-from-home (WFH) setup. This change has affected several aspects of human life especially the motivation to WFH. The study aimed to determine the motivation of WFH among office workers in the National Capital Region (NCR) from March 2020 to February 2022@*METHODS@#Using a descriptive cross-sectional study design, an online survey of WFH office workers around the NCR, Philippines was conducted. A 26-item questionnaire on motivation covering dimensions of availability (flexibility), safety (work-life balance), and meaningfulness (work performance) was used. Data was analyzed using SPSS version 24.@*RESULTS@#A total of 252 respondents were included in the study, with a majority identifying as females aged 21 to 30, never married, and college graduates. Additionally, respondents reported having one to five years of work experience and were employed in professional/technical/managerial fields. Regarding the impact of remote work, the findings indicated that most individuals who worked from home (WFH) felt motivated by this setup due to its positive effects on availability, time and cost savings from reduced commuting, and the flexibility it provided for managing their schedules according to personal preferences. Furthermore, in terms of safety and conducive work environment, WFH office workers expressed agreement that the remote work setup contributed to a favorable work environment, leading to increased job satisfaction. This setup allowed them to effectively balance work responsibilities with personal and family commitments. The study also revealed that WFH office workers perceived a sense of meaningfulness in their work, as they felt trusted and valued by their employers. This sentiment contributed to their overall well-being, both physically and mentally@*CONCLUSION@#Work-from-home office workers are generally always motivated in terms of availability (flexibility), safety (work-life balance) and meaningfulness (work performance).


Asunto(s)
Motivación , Docilidad , Rendimiento Laboral
5.
J Chem Theory Comput ; 18(12): 7193-7204, 2022 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-36384001

RESUMEN

Accurate prediction of the pKa's of protein residues is crucial to many applications in biological simulation and drug discovery. Here, we present the use of free energy perturbation (FEP) calculations for the prediction of single-protein residue pKa values. We begin with an initial set of 191 residues with experimentally determined pKa values. To isolate sampling limitations from force field inaccuracies, we develop an algorithm to classify residues whose environments are significantly affected by crystal packing effects. We then report an approach to identify buried histidines that require significant sampling beyond what is achieved in typical FEP calculations. We therefore define a clean data set not requiring algorithms capable of predicting major conformational changes on which other pKa prediction methods can be tested. On this data set, we report an RMSE of 0.76 pKa units for 35 ASP residues, 0.51 pKa units for 44 GLU residues, and 0.67 pKa units for 76 HIS residues.


Asunto(s)
Descubrimiento de Drogas , Proteínas , Entropía , Proteínas/química , Simulación por Computador , Algoritmos , Concentración de Iones de Hidrógeno
6.
Plant Reprod ; 34(4): 353-364, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34061252

RESUMEN

KEY MESSAGE: Comparative genetics and genomics among green plants, including algae, provide deep insights into the evolution of land plant sexual reproduction. Land plants have evolved successive changes during their conquest of the land and innovations in sexual reproduction have played a major role in their terrestrialization. Recent years have seen many revealing dissections of the molecular mechanisms of sexual reproduction and much new genomics data from the land plant lineage, including early diverging land plants, as well as algae. This new knowledge is being integrated to further understand how sexual reproduction in land plants evolved, identifying highly conserved factors and pathways, but also molecular changes that underpinned the emergence of new modes of sexual reproduction. Here, we review recent advances in the knowledge of land plant sexual reproduction from an evolutionary perspective and also revisit the evolution of angiosperm double fertilization.


Asunto(s)
Embryophyta , Magnoliopsida , Evolución Biológica , Embryophyta/genética , Evolución Molecular , Fertilización , Filogenia , Plantas/genética
7.
Front Plant Sci ; 11: 1318, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32983207

RESUMEN

Previous results from our lab have shown that using an optical sorter to identify Fusarium head blight (FHB) resistant breeding lines was effective at reducing the toxin deoxynivalenol (DON) and FHB-associated kernel damage. In this paper we quantified the proportion of desirable genotypes at FHB resistance QTL in lines from three selection cycles of optical sorting. Breeding lines were genotyped at loci on chromosomes 3BS, 2DL, and 5A using the following DNA markers: TaHRC, CFD233, and GWM304. TaHRC is a KASP marker for Fhb1, a major FHB resistance QTL on chromosome 3BS. CFD233 is an SSR marker for Qfhs.nau-2DL on chromosome 2DL. GWM304 is an SSR marker for Qfhs.ifa-5A on chromosome 5A. Sorter selection was effective at identifying lines that had the resistant genotype at TaHRC; in other words, the sorter was able to identify lines with resistance alleles at Fhb1. The sorter was less effective at selecting for the resistant genotype at CFD233 and GWM304. However, the proportion of lines with resistant genotypes at GWM304 did increase with additional sorter selection, just not to the degree that was observed for the Fhb1-associated marker. The proportion of lines with resistant alleles at CFD233 did not show a consistent trend. In addition to increasing the proportion of lines with Fhb1 and Qfhs.ifa-5A each selection cycle, optical sorter-based mass selection enhanced FHB resistance in different marker genotype combinations evaluated in this study. For example, there were net reductions in DON and kernel damage after two cycles of sorter selection in 15X110601S07002, a line with Fhb1, with Qfhs.nau-2DL, and with Qfhs.ifa-5A; final C3 DON levels were 63% of the resistant check (KY02C-3005-25). Kernel damage was also reduced in 15X110601A08221 a line without Fhb1, without Qfhs.nau-2DL, and without Qfhs.ifa-5A. Our findings suggest the increased resistance observed in different marker genotype combinations was conferred by QTL other than Fhb1, QFhs.nau-2DL, and Qfhs.ifa-5, and validate our previous results that the optical sorter is effective at selecting FHB-resistant breeding material.

8.
Korean J Anesthesiol ; 73(1): 30-35, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31378055

RESUMEN

BACKGROUND: Despite improvements in techniques and management of liver transplant patients, numerous perioperative complications that contribute to perioperative mortality remain. Models to predict intraoperative massive blood transfusion, prolonged mechanical ventilation, or in-hospital mortality in liver transplant recipients have not been identified. In this study we aim to identify preoperative factors associated with the above mentioned complications. METHODS: A retrospective observational analysis was conducted on data collected from 124 orthotopic liver transplants performed at a single institution between 2014 and 2017. A multivariable logistic regression using backwards elimination was performed for three defined outcomes (massive transfusion ≥ 10 units packed red blood cells (PRBC), prolonged mechanical ventilation > 24 h, and in-hospital mortality) to identify associations with preoperative characteristics. RESULTS: Statistically significant (P < 0.05) associations with massive transfusion ≥ 10 units PRBC were hepatocellular carcinoma and preoperative transfusion of PRBC. Significant associations with prolonged mechanical ventilation > 24 h were hepatitis C, alcoholic hepatitis, elevated preoperative ALT, and hepatorenal syndrome. Male gender was protective for requiring prolonged mechanical ventilation. End-stage renal disease and hepatitis B were significantly associated with increased in-hospital mortality. CONCLUSIONS: This study identified risk factors associated with common perioperative complications of liver transplantation. These factors may assist practitioners in risk stratification and may form the basis for further investigations of potential interventions to mitigate these risks.


Asunto(s)
Transfusión Sanguínea/estadística & datos numéricos , Trasplante de Hígado/métodos , Respiración Artificial/estadística & datos numéricos , Adulto , Anciano , Femenino , Mortalidad Hospitalaria , Humanos , Trasplante de Hígado/mortalidad , Masculino , Persona de Mediana Edad , Periodo Preoperatorio , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo
9.
Front Plant Sci ; 10: 517, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31068960

RESUMEN

The migration of male and female gamete nuclei to each other in the fertilized egg is a prerequisite for the blending of genetic materials and the initiation of the next generation. Interestingly, many differences have been found in the mechanism of gamete nuclear movement among animals and plants. Female to male gamete nuclear movement in animals and brown algae relies on microtubules. By contrast, in flowering plants, the male gamete nucleus is carried to the female gamete nucleus by the filamentous actin cytoskeleton. As techniques have developed from light, electron, fluorescence, immunofluorescence, and confocal microscopy to live-cell time-lapse imaging using fluorescently labeled proteins, details of these differences in gamete nuclear migration have emerged in a wide range of eukaryotes. Especially, gamete nuclear migration in flowering plants such as Arabidopsis thaliana, rice, maize, and tobacco has been further investigated, and showed high conservation of the mechanism, yet, with differences among these species. Here, with an emphasis on recent developments in flowering plants, we survey gamete nuclear migration in different eukaryotic groups and highlight the differences and similarities among species.

10.
J Mol Biol ; 431(7): 1481-1493, 2019 03 29.
Artículo en Inglés | MEDLINE | ID: mdl-30776430

RESUMEN

Building on the substantial progress that has been made in using free energy perturbation (FEP) methods to predict the relative binding affinities of small molecule ligands to proteins, we have previously shown that results of similar quality can be obtained in predicting the effect of mutations on the binding affinity of protein-protein complexes. However, these results were restricted to mutations which did not change the net charge of the side chains due to known difficulties with modeling perturbations involving a change in charge in FEP. Various methods have been proposed to address this problem. Here we apply the co-alchemical water approach to study the efficacy of FEP calculations of charge changing mutations at the protein-protein interface for the antibody-gp120 system investigated previously and three additional complexes. We achieve an overall root mean square error of 1.2 kcal/mol on a set of 106 cases involving a change in net charge selected by a simple suitability filter using side-chain predictions and solvent accessible surface area to be relevant to a biologic optimization project. Reasonable, although less precise, results are also obtained for the 44 more challenging mutations that involve buried residues, which may in some cases require substantial reorganization of the local protein structure, which can extend beyond the scope of a typical FEP simulation. We believe that the proposed prediction protocol will be of sufficient efficiency and accuracy to guide protein engineering projects for which optimization and/or maintenance of a high degree of binding affinity is a key objective.


Asunto(s)
Anticuerpos Neutralizantes/química , Entropía , Anticuerpos Anti-VIH/química , Proteína gp120 de Envoltorio del VIH/química , Mutación , Dominios y Motivos de Interacción de Proteínas , Proteínas/química , Fenómenos Biofísicos , Biología Computacional , Bases de Datos Factuales , Descubrimiento de Drogas , Proteína gp120 de Envoltorio del VIH/inmunología , Enlace de Hidrógeno , Ligandos , Simulación de Dinámica Molecular , Unión Proteica , Dominios y Motivos de Interacción de Proteínas/genética
11.
Sci Total Environ ; 630: 367-378, 2018 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-29482145

RESUMEN

Efficient and effective modelling methods to assess soil organic carbon (SOC) stock are central in understanding the global carbon cycle and informing related land management decisions. However, mapping SOC stocks in semi-arid rangelands is challenging due to the lack of data and poor spatial coverage. The use of remote sensing data to provide an indirect measurement of SOC to inform digital soil mapping has the potential to provide more reliable and cost-effective estimates of SOC compared with field-based, direct measurement. Despite this potential, the role of remote sensing data in improving the knowledge of soil information in semi-arid rangelands has not been fully explored. This study firstly investigated the use of high spatial resolution satellite data (seasonal fractional cover data; SFC) together with elevation, lithology, climatic data and observed soil data to map the spatial distribution of SOC at two soil depths (0-5cm and 0-30cm) in semi-arid rangelands of eastern Australia. Overall, model performance statistics showed that random forest (RF) and boosted regression trees (BRT) models performed better than support vector machine (SVM). The models obtained moderate results with R2 of 0.32 for SOC stock at 0-5cm and 0.44 at 0-30cm, RMSE of 3.51MgCha-1 at 0-5cm and 9.16MgCha-1 at 0-30cm without considering SFC covariates. In contrast, by including SFC, the model accuracy for predicting SOC stock improved by 7.4-12.7% at 0-5cm, and by 2.8-5.9% at 0-30cm, highlighting the importance of including SFC to enhance the performance of the three modelling techniques. Furthermore, our models produced a more accurate and higher resolution digital SOC stock map compared with other available mapping products for the region. The data and high-resolution maps from this study can be used for future soil carbon assessment and monitoring.

12.
World J Surg ; 42(7): 1939-1948, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29143088

RESUMEN

BACKGROUND: Patients with anemia frequently undergo surgery, as it is unclear at what threshold clinicians should consider delaying surgery for preoperative anemia optimization. The primary objective of this study was to determine whether there is an association of varying degrees of anemia and transfusion with 30-day mortality. METHODS: This is a retrospective cohort study using the American College of Surgeons National Surgical Quality Improvement Program database from 2011 to 2013. Cohorts were analyzed based on preoperative hematocrit range-patients with: (1) no anemia, (2) hematocrit ≥33% and <36% in females or <39% in males, (3) hematocrit ≥30% and <33%, (4) hematocrit ≥27% and <30%, (5) hematocrit ≥24% and <27%, and (6) hematocrit ≥21% and less than 24%. Multivariable logistic regression was used to analyze the association of anemia and transfusion with 30-day in-hospital mortality. RESULTS: The odds for 30-day mortality increased incrementally as the hematocrit ranges decreased, in which preoperative hematocrit between 21 and 24% had the highest odds for this outcome (odds ratio [OR] 6.50, p < 0.0001) compared to the reference group (no anemia). The use of transfusion increased the odds of mortality even further (OR 5.57, p < 0.0001). Among patients that received an intra-/postoperative transfusion, preoperative anemia was not predictive of mortality. CONCLUSIONS: Healthcare providers making preoperative clinical decisions for patients undergoing elective surgery should consider the degree of preoperative anemia and likelihood of perioperative transfusion.


Asunto(s)
Transfusión Sanguínea , Procedimientos Quirúrgicos Electivos/mortalidad , Hematócrito , Anciano , Anemia/mortalidad , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/mortalidad , Cuidados Preoperatorios , Estudios Retrospectivos , Factores de Riesgo
13.
Glob Chang Biol ; 24(6): 2403-2415, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29284201

RESUMEN

Climate change threatens global wheat production and food security, including the wheat industry in Australia. Many studies have examined the impacts of changes in local climate on wheat yield per hectare, but there has been no assessment of changes in land area available for production due to changing climate. It is also unclear how total wheat production would change under future climate when autonomous adaptation options are adopted. We applied species distribution models to investigate future changes in areas climatically suitable for growing wheat in Australia. A crop model was used to assess wheat yield per hectare in these areas. Our results show that there is an overall tendency for a decrease in the areas suitable for growing wheat and a decline in the yield of the northeast Australian wheat belt. This results in reduced national wheat production although future climate change may benefit South Australia and Victoria. These projected outcomes infer that similar wheat-growing regions of the globe might also experience decreases in wheat production. Some cropping adaptation measures increase wheat yield per hectare and provide significant mitigation of the negative effects of climate change on national wheat production by 2041-2060. However, any positive effects will be insufficient to prevent a likely decline in production under a high CO2 emission scenario by 2081-2100 due to increasing losses in suitable wheat-growing areas. Therefore, additional adaptation strategies along with investment in wheat production are needed to maintain Australian agricultural production and enhance global food security. This scenario analysis provides a foundation towards understanding changes in Australia's wheat cropping systems, which will assist in developing adaptation strategies to mitigate climate change impacts on global wheat production.


Asunto(s)
Cambio Climático , Triticum/fisiología , Aclimatación , Agricultura/métodos , Australia , Abastecimiento de Alimentos
14.
J Mol Biol ; 429(7): 923-929, 2017 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-28279701

RESUMEN

Protein side-chain mutation is fundamental both to natural evolutionary processes and to the engineering of protein therapeutics, which constitute an increasing fraction of important medications. Molecular simulation enables the prediction of the effects of mutation on properties such as binding affinity, secondary and tertiary structure, conformational dynamics, and thermal stability. A number of widely differing approaches have been applied to these predictions, including sequence-based algorithms, knowledge-based potential functions, and all-atom molecular mechanics calculations. Free energy perturbation theory, employing all-atom and explicit-solvent molecular dynamics simulations, is a rigorous physics-based approach for calculating thermodynamic effects of, for example, protein side-chain mutations. Over the past several years, we have initiated an investigation of the ability of our most recent free energy perturbation methodology to model the thermodynamics of protein mutation for two specific problems: protein-protein binding affinities and protein thermal stability. We highlight recent advances in the field and outline current and future challenges.


Asunto(s)
Proteínas Mutantes/química , Proteínas Mutantes/genética , Mutación , Proteínas/química , Proteínas/genética , Termodinámica
15.
J Mol Biol ; 429(7): 930-947, 2017 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-27908641

RESUMEN

Direct calculation of relative binding affinities between antibodies and antigens is a long-sought goal. However, despite substantial efforts, no generally applicable computational method has been described. Here, we describe a systematic free energy perturbation (FEP) protocol and calculate the binding affinities between the gp120 envelope glycoprotein of HIV-1 and three broadly neutralizing antibodies (bNAbs) of the VRC01 class. The protocol has been adapted from successful studies of small molecules to address the challenges associated with modeling protein-protein interactions. Specifically, we built homology models of the three antibody-gp120 complexes, extended the sampling times for large bulky residues, incorporated the modeling of glycans on the surface of gp120, and utilized continuum solvent-based loop prediction protocols to improve sampling. We present three experimental surface plasmon resonance data sets, in which antibody residues in the antibody/gp120 interface were systematically mutated to alanine. The RMS error in the large set (55 total cases) of FEP tests as compared to these experiments, 0.68kcal/mol, is near experimental accuracy, and it compares favorably with the results obtained from a simpler, empirical methodology. The correlation coefficient for the combined data set including residues with glycan contacts, R2=0.49, should be sufficient to guide the choice of residues for antibody optimization projects, assuming that this level of accuracy can be realized in prospective prediction. More generally, these results are encouraging with regard to the possibility of using an FEP approach to calculate the magnitude of protein-protein binding affinities.


Asunto(s)
Anticuerpos Neutralizantes/química , Anticuerpos Neutralizantes/metabolismo , Anticuerpos Anti-VIH/química , Anticuerpos Anti-VIH/metabolismo , Proteína gp120 de Envoltorio del VIH/química , Proteína gp120 de Envoltorio del VIH/metabolismo , Termodinámica , Biología Computacional , Unión Proteica , Resonancia por Plasmón de Superficie
16.
BMJ ; 353: i3329, 2016 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-27311485
17.
J Chem Theory Comput ; 12(6): 2990-8, 2016 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-27145262

RESUMEN

Ligand docking is a widely used tool for lead discovery and binding mode prediction based drug discovery. The greatest challenges in docking occur when the receptor significantly reorganizes upon small molecule binding, thereby requiring an induced fit docking (IFD) approach in which the receptor is allowed to move in order to bind to the ligand optimally. IFD methods have had some success but suffer from a lack of reliability. Complementing IFD with all-atom molecular dynamics (MD) is a straightforward solution in principle but not in practice due to the severe time scale limitations of MD. Here we introduce a metadynamics plus IFD strategy for accurate and reliable prediction of the structures of protein-ligand complexes at a practically useful computational cost. Our strategy allows treating this problem in full atomistic detail and in a computationally efficient manner and enhances the predictive power of IFD methods. We significantly increase the accuracy of the underlying IFD protocol across a large data set comprising 42 different ligand-receptor systems. We expect this approach to be of significant value in computationally driven drug design.


Asunto(s)
Ligandos , Simulación del Acoplamiento Molecular , Proteínas/química , Sitios de Unión , Quinasa 2 Dependiente de la Ciclina/química , Quinasa 2 Dependiente de la Ciclina/metabolismo , Diseño de Fármacos , Enlace de Hidrógeno , Preparaciones Farmacéuticas/química , Preparaciones Farmacéuticas/metabolismo , Unión Proteica , Estructura Terciaria de Proteína , Proteínas/metabolismo
18.
Front Microbiol ; 7: 277, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27014202

RESUMEN

Fusarium head blight (FHB), caused mainly by Fusarium graminearum Schwabe [telomorph: Gibberella zeae Schwein.(Petch)] in the US, is one of the most destructive diseases of wheat (Triticum aestivum L. and T. durum L.). Infected grain is usually contaminated with deoxynivalenol (DON), a serious mycotoxin. The challenge in FHB resistance breeding is combining resistance with superior agronomic and quality characteristics. Exotic QTL are widely used to improve FHB resistance. Success depends on the genetic background into which the QTL are introgressed, whether through backcrossing or forward crossing; QTL expression is impossible to predict. In this study four high-yielding soft red winter wheat breeding lines with little or no scab resistance were each crossed to a donor parent (VA01W-476) with resistance alleles at two QTL: Fhb1 (chromosome 3BS) and QFhs.nau-2DL (chromosome 2DL) to generate backcross and F2 progeny. F2 individuals were genotyped and assigned to 4 groups according to presence/ absence of resistance alleles at one or both QTL. The effectiveness of these QTL in reducing FHB rating, incidence, index, severity, Fusarium-damaged kernels (FDK) and DON, in F2-derived lines was assessed over 2 years. Fhb1 showed an average reduction in DON of 17.5%, and conferred significant resistance in 3 of 4 populations. QFhs.nau-2DL reduced DON 6.7% on average and conferred significant resistance in 2 of 4 populations. The combination of Fhb1 and QFhs.nau-2DL resistance reduced DON 25.5% across all populations. Double resistant lines had significantly reduced DON compared to double susceptible lines in 3 populations. Backcross derived progeny were planted in replicated yield trials (2011 and 2012) and in a scab nursery in 2012. Several top yielding lines performed well in the scab nursery, with acceptable DON concentrations, even though the average effect of either QTL in this population was not significant. Population selection is often viewed as an "all or nothing" process: if the average resistance level is insufficient, the population is discarded. These results indicate that it may be possible to find rare segregants which combine scab resistance, superior agronomic performance and acceptable quality even in populations in which the average effect of the QTL is muted or negligible.

19.
Bioinspir Biomim ; 10(6): 065006, 2015 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-26601975

RESUMEN

Robotic fish accomplish swimming by deforming their bodies or other fin-like appendages. As an emerging class of embedded computing system, robotic fish are anticipated to play an important role in environmental monitoring, inspection of underwater structures, tracking of hazardous wastes and oil spills, and the study of live fish behaviors. While integration of flexible materials (into the fins and/or body) holds the promise of improved swimming performance (in terms of both speed and maneuverability) for these robots, such components also introduce significant design challenges due to the complex material mechanics and hydrodynamic interactions. The problem is further exacerbated by the need for the robots to meet multiple objectives (e.g., both speed and energy efficiency). In this paper, we propose an evolutionary multiobjective optimization approach to the design and control of a robotic fish with a flexible caudal fin. Specifically, we use the NSGA-II algorithm to investigate morphological and control parameter values that optimize swimming speed and power usage. Several evolved fin designs are validated experimentally with a small robotic fish, where fins of different stiffness values and sizes are printed with a multi-material 3D printer. Experimental results confirm the effectiveness of the proposed design approach in balancing the two competing objectives.


Asunto(s)
Aletas de Animales/fisiología , Biomimética/instrumentación , Peces/fisiología , Modelos Biológicos , Robótica/instrumentación , Natación/fisiología , Animales , Simulación por Computador , Diseño Asistido por Computadora , Módulo de Elasticidad/fisiología , Diseño de Equipo , Análisis de Falla de Equipo , Retroalimentación Fisiológica/fisiología , Modelos Genéticos , Robótica/métodos , Navíos/instrumentación
20.
Langmuir ; 31(7): 2147-56, 2015 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-25642579

RESUMEN

The effects of surface pressure on the physical properties of Langmuir monolayers of palmitic acid (PA) and dipalmitoylphosphatidic acid (DPPA) at the air/water interface are investigated through molecular dynamics simulations with atomistic force fields. The structure and dynamics of both monolayers and interfacial water are compared across the range of surface pressures at which stable monolayers can form. For PA monolayers at T = 300 K, the untilted condensed phase with a hexagonal lattice structure is found at high surface pressure, while the uniformly tilted condensed phase with a centered rectangular lattice structure is observed at low surface pressure, in agreement with the available experimental data. A state with uniform chain tilt but no periodic spatial ordering is observed for DPPA monolayers on a Na(+)/water subphase at both high and low surface pressures. The hydrophobic acyl chains of both monolayers pack efficiently at all surface pressures, resulting in a very small number of gauche defects. The analysis of the hydrogen-bonding structure/dynamics at the monolayer/water interface indicates that water molecules hydrogen-bonded to the DPPA head groups reorient more slowly than those hydrogen-bonded to the PA head groups, with the orientational dynamics becoming significantly slower at high surface pressure. Possible implications for physicochemical processes taking place on marine aerosols in the atmosphere are discussed.

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