RESUMO
A key step in assessing the potential human and environmental health risks of industrial and agricultural chemicals is to determine the toxicity point of departure (POD), which is the highest dose level that causes no adverse effect. Transcriptomic POD (tPOD) values have been suggested to accurately estimate toxicity POD values. One step in the most common approach for tPOD determination involves mapping genes to annotated gene sets, a process that might lead to substantial information loss particularly in species with poor gene annotation. Alternatively, methods that calculate tPOD values directly from the distribution of individual gene POD values omit this mapping step. Using rat transcriptome data for 79 molecules obtained from Open TG-GATEs (Toxicogenomics Project Genomics Assisted Toxicity Evaluation System), the hypothesis was tested that methods based on the distribution of all individual gene POD values will give a similar tPOD value to that obtained via the gene set-based method. Gene set-based tPOD values using four different gene set structures were compared to tPOD values from five different individual gene distribution methods. Results revealed a high tPOD concordance for all methods tested, especially for molecules with at least 300 dose-responsive probesets: for 90% of those molecules, the tPOD values from all methods were within 4-fold of each other. In addition, random gene sets based upon the structure of biological knowledge-derived gene sets produced tPOD values with a median absolute fold change of 1.3-1.4 when compared to the original biological knowledge-derived gene set counterparts, suggesting that little biological information is used in the gene set-based tPOD generation approach. These findings indicate using individual gene distributions to calculate a tPOD is a viable and parsimonious alternative to using gene sets. Importantly, individual gene distribution-based tPOD methods do not require knowledge of biological organization and can be applied to any species including those with poorly annotated gene sets.
RESUMO
DP915635 maize was genetically modified (GM) to express the IPD079Ea protein for corn rootworm (Diabrotica spp.) control. DP915635 maize also expresses the phosphinothricin acetyltransferase (PAT) protein for tolerance to glufosinate herbicide and the phosphomannose isomerase (PMI) protein that was used as a selectable marker. A field study was conducted at ten sites in the United States and Canada during the 2019 growing season. Of the 11 agronomic endpoints that were evaluated, two of them (early stand count and days to flowering) were statistically significant compared with the control maize based on unadjusted p-values; however, these differences were not significant after FDR-adjustment of p-values. Composition analytes from DP915635 maize grain and forage (proximates, fiber, minerals, amino acids, fatty acids, vitamins, anti-nutrients, and secondary metabolites) were compared to non-GM near-isoline control maize (control maize) and non-GM commercial maize (reference maize). Statistically significant differences were observed for 7 of the 79 compositional analytes (16:1 palmitoleic acid, 18:0 stearic acid, 18:1 oleic acid, 18:2 linoleic acid, 24:0 lignoceric acid, methionine, and α-tocopherol); however, these differences were not significant after FDR-adjustment. Additionally, all of the values for composition analytes fell within the range of natural variation established from the in-study reference range, literature range, and/or tolerance interval. These results demonstrate that DP915635 is agronomically and compositionally comparable to non-GM maize represented by non-GM near-isoline control maize and non-GM commercial maize.
Assuntos
Aminoácidos , Zea mays , Estados Unidos , Zea mays/genética , Zea mays/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Aminoácidos/metabolismo , Grão Comestível/metabolismo , Vitaminas/metabolismoRESUMO
Jonathan Shay argued that social, relational, and institutional contexts were central to understanding moral injury and conceptualised moral injury as a normative response to the betrayal of an individual's understanding of what is right by a more senior/authoritative "other". Using the conceptual lens of moral injury, this paper investigates academic staff experiences of HE during the COVID-19 pandemic and explores the rapid transition back to face-to-face teaching that took place in autumn 2020. To collect data, we used an online survey that opened in January 2021 and ran until the end of March 2021. A total of 663 complete questionnaires were received across the survey period. The questionnaire was comprised of ten topic-related questions, each of which included follow-up sub-questions and also invited participants to write in additional information. The majority of participants felt that during the course of the COVID-19 pandemic, they had acted in ways that put their own health and wellbeing at risk. Of those who had acted in ways that put their health and wellbeing at risk, they believed that their senior management were the most responsible for them acting in such ways, followed by the UK government. Qualitative data showed a systemic absence of leadership in the sector during the time, a sense of betrayal of staff and students by senior management and the government, and feelings of compulsion to act in ways which put lives at risk. On the basis of these results, we argue that there could be synergies between the situation facing healthcare staff and academics during the pandemic. Many of the experiences of HE academic staff during the pandemic reported to us in this research are resonant with the concepts of betrayal and moral injury and resulted in affective responses which we understand here in relation to feelings of guilt, shame, and anger, leading ultimately to poor mental health and wellbeing. This paper discusses implications for the HE sector going forward.
RESUMO
Western corn rootworm (Diabrotica virgifera virgifera LeConte) is a major pest of corn in both North America and Europe and as such presents significant challenges for farmers. IPD079Ea protein is encoded by the ipd079Ea gene from Ophioglossum pendulum (a species of fern) and was found to have activity against western corn rootworm in multiple corn events transformed to express the IPD079Ea protein. In chronic laboratory hazard studies, IPD079Ea protein was fed to eleven species in the order Coleoptera and four species in the order Lepidoptera to assess the spectrum of activity. Activity was observed on certain species of the Chrysomelidae and Coccinellidae families, with western corn rootworm as the most sensitive insect tested. No adverse effects on mortality or other sublethal endpoints were observed on any species within Lepidoptera. Overall, IPD079Ea protein appears not to have broad insecticidal properties and has potential value as an effective trait to control western corn rootworm in agricultural systems.
Assuntos
Bacillus thuringiensis , Besouros , Animais , Bacillus thuringiensis/genética , Besouros/genética , Endotoxinas , Larva , Controle Biológico de Vetores , Plantas Geneticamente Modificadas/genética , Zea mays/genéticaRESUMO
Event DP-Ø23211-2 (hereafter referred to as DP23211) maize expresses the DvSSJ1 double-stranded RNA (DvSSJ1 dsRNA) and the IPD072Aa protein, encoded by the ipd072Aa gene. DvSSJ1 dsRNA and the IPD072Aa protein each provide control of corn rootworms (Diabrotica spp.) when expressed in plants. As part of the environmental risk assessment (ERA), the potential hazard to non-target organisms (NTOs) exposed to the DvSSJ1 dsRNA and the IPD072Aa protein expressed in DP23211 maize was assessed. Worst-case estimated environmental concentrations (EECs) for different NTO functional groups (pollinators and pollen feeders, soil dwelling detritivores, predators and parasitoids, aquatic detritivores, insectivorous birds, and wild mammals) were calculated using worst-case assumptions. Several factors that reduce exposure to NTOs under more realistic environmental conditions were applied, when needed to provide more environmentally relevant EECs. Laboratory bioassays were conducted to assess the activity of DvSSJ1 dsRNA or the IPD072Aa protein against selected surrogate species, and margins of exposure (MOEs) were calculated by comparing the Tier I hazard study results to worst-case or refined EECs. Based on specificity and MOE values, DvSSJ1 dsRNA and the IPD072Aa protein expressed in DP23211 maize are not expected to be harmful to NTO populations at environmentally relevant concentrations.
Assuntos
Besouros , RNA de Cadeia Dupla , Animais , Besouros/genética , Plantas Geneticamente Modificadas/genética , RNA de Cadeia Dupla/genética , Medição de Risco , Zea mays/genéticaRESUMO
Feeding studies were conducted with rats and broiler chickens to assess the safety and nutrition of maize grain containing event DP-Ø23211-2 (DP23211), a newly developed trait-pyramid product for corn rootworm management. Diets containing 50% ground maize grain from DP23211, non-transgenic control, or non-transgenic reference hybrids (P0928, P0993, and P1105) were fed to Crl:CD®(SD) rats for 90 days. Ross 708 broilers were fed phase diets containing up to 67% maize grain from each source for 42 days. Body weight, gain, and feed conversion were determined for comparisons between animals fed DP23211 and control diets in each study. Additional measures included clinical and neurobehavioral evaluations, ophthalmology, clinical pathology, organ weights, and gross and microscopic pathology for rats, and carcass parts and select organ yields for broilers. Reference groups were included to determine if any observed significant differences between DP23211 and control groups were likely due to natural variation. No diet-related effects on mortality or evaluation measures were observed between animal fed diets produced with DP23211 maize grain and animal fed diets produced with control maize grain. These studies show that maize grain containing event DP-Ø23211-2 is as safe and nutritious as non-transgenic maize grains when fed in nutritionally adequate diets. The results are consistent with previously published studies, providing further demonstration of the absence of hazards from edible-fraction consumption of genetically modified plants.
Assuntos
Galinhas , Zea mays , Ração Animal/análise , Animais , Grão Comestível , Plantas Geneticamente Modificadas , Ratos , Zea mays/genéticaRESUMO
Event DP-2Ø2216-6 (referred to as DP202216 maize) was genetically modified to increase and extend the expression of the introduced zmm28 gene relative to endogenous zmm28 gene expression, resulting in plants with enhanced grain yield potential. The zmm28 gene expresses the ZMM28 protein, a MADS-box transcription factor. The safety assessment of DP202216 maize included an assessment of the potential hazard of the ZMM28 protein, as well as an assessment of potential unintended effects of the genetic insertion on agronomics, composition, and nutrition. The history of safe use (HOSU) of the ZMM28 protein was evaluated and a bioinformatics approach was used to compare the deduced amino acid sequence of the ZMM28 protein to databases of known allergens and toxins. Based on HOSU and the bioinformatics assessment, the ZMM28 protein was determined to be unlikely to be either allergenic or toxic to humans. The composition of DP202216 maize forage and grain was comparable to non-modified forage and grain, with no unintended effects on nutrition or food and feed safety. Additionally, feeding studies with broiler chickens and rats demonstrated a low likelihood of unintentional alterations in nutrition and low potential for adverse effects. Furthermore, the agronomics observed for DP202216 maize and non-modified maize were comparable, indicating that the likelihood of increased weediness or invasiveness of DP202216 maize in the environment is low. This comprehensive review serves as a reference for regulatory agencies and decision-makers in countries where authorization of DP202216 maize will be pursued, and for others interested in food, feed, and environmental safety.
Assuntos
Galinhas , Zea mays , Alérgenos , Ração Animal , Animais , Produtos Agrícolas/genética , Plantas Geneticamente Modificadas , Ratos , Zea mays/genéticaRESUMO
The objective was to evaluate a multidisciplinary guideline-driven disease management program focused on achievement of asthma control among sustained patients with confirmed asthma in Louisiana and to assess factors affecting achievement of asthma control. Data were extracted from the electronic health records of 1596 adults with confirmed asthma, sustained care for >1 year in the outpatient setting, and ≥2 recorded Asthma Control Test (ACT) scores. Multivariable logistic regression modeling was used to assess the association of demographic variables, comorbidities, and process measures with the best achieved asthma control as represented by the highest ACT score. Most subjects were female (81.1%) and African American (63.9%). Approximately half of them (48.9%) were able to achieve asthma control (ACT ≥20). The most prevalent comorbidities were hypertension (79.8%), rhinitis (55.3%), and obesity (50.5%). Most patients received pulmonary function testing (PFT) (88.6%), controller medication therapy (85.5%), or written asthma action plans (92.7%). Asthma control was positively associated with presence of PFT (OR = 1.63, 95% CI: 1.13, 2.37) and being a "never" smoker (OR = 1.49, 95% CI: 1.08, 2.04). Asthma control was less likely to be achieved by patients who were African American (OR = 0.68, 95% CI: 0.52, 0.87), had more comorbidities (OR = 0.89, 95% CI: 0.83, 0.96), or were on more medications (OR = 0.79, 95% CI: 0.72, 0.88). Asthma control was achieved in 48.9% of an adult, primarily African American population with the implementation of comprehensive guideline-driven care. Furthermore, this is the first study to observe that the presence of PFT may be associated with asthma control.
Assuntos
Asma , Provedores de Redes de Segurança , Adulto , Negro ou Afro-Americano , Asma/tratamento farmacológico , Asma/epidemiologia , Gerenciamento Clínico , Feminino , Humanos , Modelos LogísticosRESUMO
Generating negative news coverage of state welfare provision has been identified as a strategy designed to create public support for radical policies aimed to reduce such provision. To date, research of this kind has focused on scandals and crises. However, little is known about the complex relationship between media representations of specific events, and those of media representations in the lead up to these events, what we refer to as periphery representations. Employing a content and frame analysis, this paper analyses the frequency and intensity of peripheral representations of the National Health Service (NHS) in the British print media for 1 week a month before and for 1 week during three key events in recent NHS history: the official consultation period for the Health and Social Care Act; the publication of Five-Year Forward View, and the first Junior Doctor Strike. This article finds that negative NHS representations in articles that are peripheral to particular topical issues of controversy evidence fluctuations, amplifications and intensities across time periods, depending on the particular context. The paper concludes by arguing that repetition of negative themes in news helps to build a sensibility of 'inadequacy' of vital services. We hope that this focus on the ways in which amplifications and de-amplifications in negative intensity of peripheral NHS representations across time and content, helps to contribute to debate about the complex interplay between public health services, media representation and policy consent.
Assuntos
Meios de Comunicação de Massa , Medicina Estatal , Humanos , Reino UnidoRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
Transgenic maize plants expressing dsRNA targeting western corn rootworm (WCR, Diabrotica virgifera virgifera) DvSSJ1 mRNA, a Drosophila snakeskin (ssk) ortholog, show insecticidal activity and significant plant protection from WCR damage. The gene encodes a membrane protein associated with the smooth sepate junction (SSJ) which is required for intestinal barrier function. To understand the active RNA form that leads to the mortality of WCR larvae by DvSSJ1 RNA interference (RNAi), we characterized transgenic plants expressing DvSSJ1 RNA transcripts targeting WCR DvSSJ1 mRNA. The expression of the silencing cassette results in the full-length transcript of 901 nucleotides containing a 210 bp inverted fragment of the DvSSJ1 gene, the formation of a double-stranded RNA (dsRNA) transcript and siRNAs in transgenic plants. Our artificial diet-feeding study indicates that dsRNAs greater than or equal to approximately 60 base-pairs (bp) are required for DvSSJ1 insecticidal activity. Impact of specificity of dsRNA targeting DvSSJ1 mRNA on insecticidal activities was also evaluated in diet bioassay, which showed a single nucleotide mutation can have a significant impact or abolish diet activities against WCR. These results provide insights as to the functional forms of plant-delivered dsRNA for the protection of transgenic maize from WCR feeding damage and information contributing to the risk assessment of transgenic maize expressing insecticidal dsRNA.
Assuntos
Besouros , Controle Biológico de Vetores/métodos , Plantas Geneticamente Modificadas/genética , Zea mays/genética , Animais , Besouros/metabolismo , Proteínas de Insetos/genética , Junções Intercelulares/metabolismo , Larva , Interferência de RNA , RNA de Cadeia Dupla/genéticaRESUMO
DP23211 maize was genetically modified (GM) to express DvSSJ1 double-stranded RNA and the IPD072Aa protein for control of corn rootworm (Diabrotica spp.). DP23211 maize also expresses the phosphinothricin acetyltransferase (PAT) protein for tolerance to glufosinate herbicide, and the phosphomannose isomerase (PMI) protein that was used as a selectable marker. A multi-location field trial was conducted during the 2018 growing season at 12 sites selected to be representative of the major maize-growing regions of the U.S. and Canada. Standard agronomic endpoints as well as compositional analytes from grain and forage (e.g., proximates, fibers, minerals, amino acids, fatty acids, vitamins, anti-nutrients, secondary metabolites) were evaluated and compared to non-GM near-isoline control maize (control maize) and non-GM commercial maize (reference maize). A small number of agronomic endpoints were statistically significant compared to the control maize, but were not considered to be biologically relevant when adjusted using the false discovery rate method (FDR) or when compared to the range of natural variation established from in-study reference maize. A small number of composition analytes were statistically significant compared to the control maize. These analytes were not statistically significant when adjusted using FDR, and all analyte values fell within the range of natural variation established from in-study reference range, literature range or tolerance interval, indicating that the composition of DP23211 maize grain and forage is substantially equivalent to conventional maize represented by non-GM near-isoline control maize and non-GM commercial maize.
Assuntos
Grão Comestível , Zea mays/genética , Aminoácidos , Canadá , Plantas Geneticamente ModificadasRESUMO
A recent perspective defends the approach of the European Food Safety Authority (EFSA) for evaluating the compositional normality of genetically engineered (GE) crops using a concurrently grown subset of non-GE varieties within the risk assessment. While the approach of the EFSA manages the risk of falsely claiming equivalence, this is achieved at the expense of low power to detect true equivalence. This generates inconsistent findings and safety conclusions across studies for the same GE event based on the selected non-GE comparators. Because variation in GE crop composition has not been associated with safety, we suggest policy improvements that would better align with consumer protection.
RESUMO
1,3-Dichloropropene (1,3-D) showed a statistically increased incidence of bronchioloalveolar adenomas in male B6C3F1 mice at 60 ppm air concentration during previous chronic inhalation testing. No tumors were observed in female mice, nor in either sex of F344 rats up to 60 ppm, the highest dose tested. Therefore, to understand if lung tumors observed in high dose male mice are due to saturation of metabolic clearance, the linearity of 1,3-D concentrations in mouse blood was investigated on day 15 of repeated nose-only inhalation exposure to 0, 10, 20, 40, 60, 90, and 120 ppm (6 h/d, 7 d/week). Additional groups were included at 20, 60, and 120 ppm for blood collection at 1.5 and 3 h of exposure and up to 25 or 40 min post-exposure to determine area-under-the-curve. The data provide multiple lines of evidence that systemic exposures to 1,3-D in the mouse become nonlinear at inhalation exposure levels of 30 ppm or above. A reduction in minute volume occurred at the highest exposure concentration. The glutathione (GSH)-dependent metabolism of 1,3-D results in significant depletion of GSH at repeated exposure levels of 30 ppm and above. This loss of GSH results in decreased metabolic clearance of this test material, with a concomitant increase of the 1,3-D isomers in circulating blood at exposure concentrations ≥30 ppm. Shifts in the ratio of cis- and trans-1,3-D also support nonlinear toxicokinetics well below 60 ppm. Based on this data, a kinetically derived maximum dose for 1,3-D in mice for repeated exposures should be at or below 30 ppm. These results support non-relevance of 1,3-D-induced benign pulmonary tumorigenicity in mice for human health risk assessment.
Assuntos
Adenoma/induzido quimicamente , Compostos Alílicos/toxicidade , Carcinógenos/toxicidade , Hidrocarbonetos Clorados/toxicidade , Neoplasias Pulmonares/induzido quimicamente , Pulmão/efeitos dos fármacos , Modelos Teóricos , Adenoma/metabolismo , Compostos Alílicos/sangue , Compostos Alílicos/farmacocinética , Animais , Carcinógenos/metabolismo , Carcinógenos/farmacocinética , Transformação Celular Neoplásica/induzido quimicamente , Transformação Celular Neoplásica/metabolismo , Relação Dose-Resposta a Droga , Feminino , Hidrocarbonetos Clorados/sangue , Hidrocarbonetos Clorados/farmacocinética , Exposição por Inalação , Pulmão/metabolismo , Neoplasias Pulmonares/metabolismo , Masculino , Camundongos , Dinâmica não Linear , Ratos Endogâmicos F344 , Taxa Respiratória/efeitos dos fármacos , Medição de Risco , Fatores Sexuais , Distribuição Tecidual , ToxicocinéticaRESUMO
INTRODUCTION: Quitting smoking has been proven to benefit smokers with diabetes. However, among older patients with diabetes, the evidence regarding an association between smoking status and the risk of type 2 diabetes mellitus-related emergency department (ED) visits has not been well investigated. METHODS: A retrospective cohort study was performed by using the Louisiana State University Health Care Services Division electronic health records from 2009 to 2011. Patients aged 65 years or older with type 2 diabetes and smoking status recorded at least twice in 2010 were selected. Selected patients with diabetes were classified into nonsmokers, former smokers, continuing smokers, and relapsed smokers. Cox proportional hazards regression models were used to estimate the adjusted hazard ratio (aHR) of 1-year type 2 diabetes-related ED visits for each group compared with nonsmokers. RESULTS: There were 174 (8.2%) continuing smokers and 77 (3.6%) relapsed smokers in 2,114 patients with diabetes who were studied. Rates of type 2 diabetes-related ED visits were highest in relapsed smokers (28.6%). Compared with nonsmokers, relapsed smokers had a significantly higher risk of type 2 diabetes-related ED visits (aHR = 1.62; 95% confidence interval [CI], 1.04-2.50). After stratifying by sex, a significantly increased risk of type 2 diabetes-related ED visits was shown only in male relapsed smokers (aHR = 2.05; 95% CI, 1.13-3.71) and female continuing smokers (aHR = 1.65; 95% CI, 1.10-2.47) compared with nonsmokers. CONCLUSION: Older men with diabetes who were relapsed smokers had a higher risk of type 2 diabetes-related ED visits. Future research and clinical practice should focus on these patients and create more effective interventions for smoking cessation and diabetes management.
Assuntos
Diabetes Mellitus Tipo 2/patologia , Abandono do Hábito de Fumar , Fumar Tabaco/efeitos adversos , Idoso , Serviço Hospitalar de Emergência , Feminino , Humanos , Louisiana , Masculino , Modelos de Riscos Proporcionais , Recidiva , Estudos Retrospectivos , Fatores de RiscoRESUMO
Increasing maize grain yield has been a major focus of both plant breeding and genetic engineering to meet the global demand for food, feed, and industrial uses. We report that increasing and extending expression of a maize MADS-box transcription factor gene, zmm28, under the control of a moderate-constitutive maize promoter, results in maize plants with increased plant growth, photosynthesis capacity, and nitrogen utilization. Molecular and biochemical characterization of zmm28 transgenic plants demonstrated that their enhanced agronomic traits are associated with elevated plant carbon assimilation, nitrogen utilization, and plant growth. Overall, these positive attributes are associated with a significant increase in grain yield relative to wild-type controls that is consistent across years, environments, and elite germplasm backgrounds.
Assuntos
Produtos Agrícolas/genética , Grão Comestível , Genes de Plantas , Zea mays/genética , Sequência de Aminoácidos , Produtos Agrícolas/enzimologia , Glutamato-Amônia Ligase/metabolismo , Nitrato Redutase/metabolismo , Nitrogênio/metabolismo , Fotossíntese/genética , Folhas de Planta/fisiologia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Ligação Proteica , Transcriptoma , Zea mays/enzimologiaRESUMO
Saccharomyces cerevisiae genetically engineered to enhance butanol production will be used in a manufacturing process similar to that of fuel ethanol production, including co-production of distillers products for animal feed. A poultry feeding trial was conducted with simulated isobutanol-derived dried distillers grains with solubles (bDDGS), comprising non-fermentable corn solids and heat-inactivated Butamax modified yeast (BMY), to determine potential health effects. Simulated dried distillers grains were produced in 2 variants: bDDGS containing 10% (B10) or 50% (B50) BMY. The BMY concentrations were selected based on a conservative estimate from ethanol-derived distillers grains (eDDGS) approximating 2.5 and 12-fold margins of exposure. The B10 and B50 DDGS were evaluated in a 42-day feeding trial using male Ross 708 broiler chickens fed diets containing eDDGS, B50 DDGS, or B10 DDGS without or with isobutanol, 2,3-butanediol, and isobutyric acid metabolites each at target concentrations of 2 (B10-2), 5 (B10-5), or 10 (B10-10) times the anticipated specification limit in the commercial product. Diets were fed (n = 50 broilers/treatment) in 3 phases: starter phase with 8% DDGS and grower and finisher phases each with 15% DDGS. No statistically significant differences or diet-related effects on mortality, clinical pathology, or organ weights, and no microscopic observations associated with consumption of diets containing B10, B50, or B10 supplemented with metabolites at any targeted exposure level were observed. A lower (P < 0.05) mean absolute bursa of Fabricius weight in the B10-10 group compared to the B10 group was considered to be within the range of biological variability. A non-significant trend toward lower weight, gains, and feed intake, and higher feed:gain ratio was observed in the B10-10 group, and was considered a non-adverse palatability effect of consuming high concentrations of metabolites. These results demonstrate that consumption of phase diets containing simulated DDGS from a novel isobutanol production process was well-tolerated.
Assuntos
Ração Animal/análise , Butanóis/administração & dosagem , Ração Animal/efeitos adversos , Fenômenos Fisiológicos da Nutrição Animal , Animais , Biocombustíveis , Butanóis/efeitos adversos , Butanóis/metabolismo , Galinhas/crescimento & desenvolvimento , Destilação/métodos , Grão Comestível/química , Fermentação , Engenharia Genética , Masculino , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , SegurançaRESUMO
The objective of this work was to compare several models of body weight data from 90-day rodent feeding trials. Polynomial and nonlinear functions relating time and weight were examined as were the use of Toeplitz error covariance structures and random coefficients. The models were evaluated by fitting them to five publicly available datasets from rat feeding studies. Model performance was assessed in terms of their ability to capture the complexity of the growth patterns, validity of necessary assumptions, and information criteria scores. The results demonstrated the importance of selecting a curve function that effectively reflects the mean response. Toeplitz error covariance structures resulted in superior model fit, while failing to address deviations from model assumptions. Models using the Richards function and random coefficients were generally superior to the other models evaluated and dramatically improved upon linear models with complex error structures.
Assuntos
Peso Corporal , Modelos Estatísticos , Animais , Ingestão de Alimentos , Feminino , Masculino , Dinâmica não Linear , RatosRESUMO
DP202216 maize was genetically modified to increase and extend the expression of the zmm28 gene relative to native zmm28 gene expression, resulting in plants with enhanced grain yield potential. Standard nutritional and compositional parameters for maize grain and forage (e.g., proximates, fiber, minerals, amino acids, fatty acids, vitamins, anti-nutrients, secondary metabolites) from DP202216 maize were compared to grain and forage from non-modified near-isoline maize (control). Three amino acids (glycine, methionine, and serine) and two vitamins (vitamin B1 and vitamin B3) were statistically different between DP202216 and control maize grain but were not statistically different when adjusted using the false discovery rate method. These analyte values also fell within the ranges of natural variation of non-modified commercial maize varieties supporting that statistical differences were not biologically relevant. The composition of grain and forage from DP202216 maize is comparable to grain and forage from non-modified maize with a history of safe use.
Assuntos
Grão Comestível/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Zea mays/metabolismo , Aminoácidos/metabolismo , Niacinamida/metabolismo , Tiamina/metabolismoRESUMO
The European Food Safety Authority (EFSA) oversees the safety assessment of genetically engineered (GE) crops in the European Union and has developed a study design and statistical approach for assessing the compositional equivalency between a GE crop and the corresponding non-GE crop on the basis of the results from a small number of concurrently grown reference lines. Confidence limits around the differences in mean analyte composition between the GE variety and the reference lines are compared with equivalence limits on the basis of the variability of the reference lines. Here, we evaluated the performance and consistency of the equivalence conclusions using a non-GE variety that is, by definition, equivalent to the non-GE crop. Using this approach across the same analytes with the same non-GE variety, it was found that equivalence could not be concluded for 19.7, 22.9, 25.4, and 53.5% of the analytes in four separate studies. In addition, equivalency conclusions for the same analyte often differed from study to study. These results call into question the consistency and value of this approach in the risk assessment of GE crops.