RESUMO
OBJECTIVE: Radon (Rn-222) is a noble gas formed in the uranium path (U-238) as a decay product of radium (Ra-226). It is estimated to cause between 3% to 14% of all lung cancers, depending on the national average radon level and smoking prevalence. Radon molecules emit alpha radiation, which is characterized by low permeability through tissues, but due to its remarkably high energy, it has a high potential for DNA damage. The aim of our research was to assess the radon concentration inside the houses of patients with advanced lung cancer and to analyze their socio-economics status. PATIENTS AND METHODS: The measurements of radon concentration were performed in 102 patients with stage 3B or higher lung cancer in the region of Lublin, Poland. One month of radon exposure measurement was performed with alpha-track detectors. In addition, patients filled in a detailed survey about factors that might influence the concentration of radon inside their houses. RESULTS: The average concentration of radon during the exposure of the detector in the residential premises of the respondents was at the level of 69.0 Bq/m3 [37.0-117.0]. A few significant correlations were discovered, e.g., higher levels of radon in countryside houses or in houses equipped with air conditioning. CONCLUSIONS: As radon exposure is a modifiable risk factor for lung cancer, it is extremely important to find factors that may reduce its concentration in dwelling places. Since our research was performed in houses of people with lung cancer, taking corrective actions based on our findings could prevent new lung cancer incidence in patients' flatmates.
Assuntos
Neoplasias Pulmonares , Radônio , Urânio , Humanos , Polônia/epidemiologia , Condições Sociais , Radônio/efeitos adversos , Neoplasias Pulmonares/epidemiologiaRESUMO
Initiation of intervertebral disc degeneration is thought to be biologically driven. This reflects a process, where biochemical and mechanical stimuli affect cell activity (CA) that compromise the tissue strength over time. Experimental research enhanced our understanding about the effect of such stimuli on different CA, such as protein synthesis or mRNA expression. However, it is still unclear how cells respond to their native environment that consists of a "cocktail" of different stimuli that might locally vary. This work presents an interdisciplinary approach of experimental and in silico research to approximate Nucleus Pulposus CA within multifactorial biochemical environments. Thereby, the biochemical key stimuli glucose, pH, and the proinflammatory cytokines TNF-α and IL1ß were considered that were experimentally shown to critically affect CA. To this end, a Nucleus Pulposus multicellular system was modelled. It integrated experimental findings from in vitro studies of human or bovine Nucleus Pulposus cells, to relate the individual effects of targeted stimuli to alterations in CA. Unknown stimulus-CA relationships were obtained through own experimental 3D cultures of bovine Nucleus Pulposus cells in alginate beads. Translation of experimental findings into suitable parameters for network modelling approaches was achieved thanks to a new numerical approach to estimate the individual sensitivity of a CA to each stimulus type. Hence, the effect of each stimulus type on a specific CA was assessed and integrated to approximate a multifactorial stimulus environment. Tackled CA were the mRNA expressions of Aggrecan, Collagen types I & II, MMP3, and ADAMTS4. CA was assessed for four different proinflammatory cell states; non-inflamed and inflamed for IL1ß, TNF-α or both IL1ß&TNF-α. Inflamed cell clusters were eventually predicted in a multicellular 3D agent-based model. Experimental results showed that glucose had no significant impact on proinflammatory cytokine or ADAMTS4 mRNA expression, whereas TNF-α caused a significant catabolic shift in most explored CA. In silico results showed that the presented methodology to estimate the sensitivity of a CA to a stimulus type importantly improved qualitative model predictions. However, more stimuli and/or further experimental knowledge need to be integrated, especially regarding predictions about the possible progression of inflammatory environments under adverse nutritional conditions. Tackling the multicellular level is a new and promising approach to estimate manifold responses of intervertebral disc cells. Such a top-down high-level network modelling approach allows to obtain information about relevant stimulus environments for a specific CA and could be shown to be suitable to tackle complex biological systems, including different proinflammatory cell states. The development of this methodology required a close interaction with experimental research. Thereby, specific experimental needs were derived from systematic in silico approaches and obtained results were directly used to enhance model predictions, which reflects a novelty in this research field. Eventually, the presented methodology provides modelling solutions suitable for multiscale approaches to contribute to a better understanding about dynamics over multiple spatial scales. Future work should focus on an amplification of the stimulus environment by integrating more key relevant stimuli, such as mechanical loading parameters, in order to better approximate native physiological environments.
RESUMO
Intervertebral disc (IVD) degeneration and consequent low back pain (LBP) are common and costly pathological processes that require improved treatment strategies. Transient Receptor Potential (TRP) channels constitute a family of multimodal ion channels that have recently emerged as contributors to disc pathologies and were thus proposed as potential therapeutic targets, although limited data on their presence and function in the IVD exist. The purpose of this study was to determine the mRNA and protein expression of TRP channels in non-degenerated and degenerated human IVD tissue (with different pain intensity and chronicity) using gene array, conventional qPCR and immunohistochemistry. We could demonstrate that 26 out of 28 currently known TRP channels are expressed in the IVD on the mRNA level, thereby revealing novel therapeutic candidates from the TRPC, TRPM and TRPML subfamilies. TRPC6, TRPM2 and TRPML1 displayed enhanced gene and protein expression in degenerated IVDs as compared to non-degenerated IVDs. Additionally, the gene expression of TRPC6 and TRPML1 was influenced by the IVD degeneration grade. Pain intensity and/or chronicity influenced the gene and/or protein expression of TRPC6, TRPM2 and TRML1. Interestingly, decreased gene expression of TRPM2 was observed in patients treated with steroids. This study supports the importance of TRP channels in IVD homeostasis and pathology and their possible application as pharmacological targets for the treatment of IVD degeneration and LBP. However, the exact function and activation of the highlighted TRP channels will have to be determined in future studies.
Assuntos
Dor nas Costas/metabolismo , Regulação da Expressão Gênica , Degeneração do Disco Intervertebral/metabolismo , Disco Intervertebral/metabolismo , Canais de Potencial de Receptor Transitório/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Dor nas Costas/genética , Dor nas Costas/patologia , Feminino , Humanos , Disco Intervertebral/patologia , Degeneração do Disco Intervertebral/genética , Degeneração do Disco Intervertebral/patologia , Masculino , Pessoa de Meia-Idade , Canais de Potencial de Receptor Transitório/genéticaRESUMO
Although the overall incidence of trauma-induced crush syndrome (CS) is as low as 0.1 per 10,000 of population, which makes it one of the least common traumatic injuries, the hazard of CS lies in the high incidence of hemodynamic and metabolic complications, which call for an early diagnosis of this syndrome. This paper reports the specific features of cell death of neutrophils in rat blood as they changed with time using the model of endogenous toxemia formed in a setting of crush syndrome. To assess apoptosis/necrosis in neutrophils ANNEXIN V FITC assay kit (manufactured by Beckmann Coulter, USA) was used. The results obtained in this study suggest an increase in apoptotic and necrotic processes in a setting of CS from the first day of the experiment through the end of observation. Also we have found a significant impact of reactive oxygen species generation on neutrophils death in a setting of CS. However, other mechanisms to launch apoptosis/necrosis in case of experimental crush syndrome should not be neglected.
Assuntos
Morte Celular , Síndrome de Esmagamento , Neutrófilos , Animais , Apoptose , Síndrome de Esmagamento/fisiopatologia , Necrose , RatosRESUMO
Intervertebral disc (IVD) cells are naturally exposed to high osmolarity and complex mechanical loading, which drive microenvironmental osmotic changes. Age- and degeneration-induced degradation of the IVD's extracellular matrix causes osmotic imbalance, which, together with an altered function of cellular receptors and signalling pathways, instigates local osmotic stress. Cellular responses to osmotic stress include osmoadaptation and activation of pro-inflammatory pathways. This review summarises the current knowledge on how IVD cells sense local osmotic changes and translate these signals into physiological or pathophysiological responses, with a focus on inflammation. Furthermore, it discusses the expression and function of putative membrane osmosensors (e.g. solute carrier transporters, transient receptor potential channels, aquaporins and acid-sensing ion channels) and osmosignalling mediators [e.g. tonicity response-element-binding protein/nuclear factor of activated T-cells 5 (TonEBP/NFAT5), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)] in healthy and degenerated IVDs. Finally, an overview of the potential therapeutic targets for modifying osmosensing and osmosignalling in degenerated IVDs is provided.
Assuntos
Inflamação/patologia , Disco Intervertebral/patologia , Osmorregulação , Osmose , Transdução de Sinais , Animais , Humanos , Concentração OsmolarRESUMO
Thoron (220 Rn) is a natural radioactive gas, tasteless, odourless, colourless, undetectable without proper equipment. This gas is carcinogenic, just like radon (222 Rn) but due to the short half-life (55.6s) and a small amount in the environment, its share in the absorbed radiation dose is often neglected. However, in areas rich in thorium (232Th), the radiation dose from the thoron can be much larger and quite significant. The problem is to measure the concentration of the thoron due to its short decay time as well as the fact that it is alpha-emitting as radon. An even greater challenge is to determine the emanation coefficient for the thoron. The method used in this experiment was developed by S.D. Kanse based on the work of D.J Greeman and adapted to the equipment used in Laboratory of Radiometric Expertise IFJ PAN. In the technique used to determine the thoron emanation coefficient, a closed loop system is used in which thoron is pushed out by means of a flow system from the sample and measured by a AlphaGuad DF2000 detector that is adapted to determine concentration of this gas. A sample of the material is placed between 2 filters in the geometry of the sandwich. This arrangement ensures that the thickness of the powder sample is significantly less than the length of the thoron diffusion, thus avoiding significant loss of the thoron due to intergranular absorption and facilitates the complete removal of this gas escaping from the powder. Using this technique, it is important to determine the concentration of 226Ra and the 232Th, since for the AlphaGuard detector, the ratio between thoron and radon should not exceed 5:1 for proper determination of the thoron concentration. Measurements of 226Ra and 232Th activity were carried out using gamma spectroscopy (HPGe detector). It was examined how the type of filter and grain size of sample affects the obtained results.
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Poluentes Radioativos do Ar/análise , Monitoramento de Radiação/métodos , Tório/análise , Meia-Vida , RadiometriaRESUMO
Data analysis and management in high content screening (HCS) has progressed significantly in the past 10 years. The analysis of the large volume of data generated in HCS experiments represents a significant challenge and is currently a bottleneck in many screening projects. In most screening laboratories, HCS has become a standard technology applied routinely to various applications from target identification to hit identification to lead optimization. An HCS data management and analysis infrastructure shared by several research groups can allow efficient use of existing IT resources and ensures company-wide standards for data quality and result generation. This chapter outlines typical HCS workflows and presents IT infrastructure requirements for multi-well plate-based HCS.
Assuntos
Ensaios de Triagem em Larga Escala , Processamento de Imagem Assistida por Computador , Armazenamento e Recuperação da Informação , Imagem Molecular , Sistemas de Gerenciamento de Base de Dados , Descoberta de Drogas/métodos , Humanos , Imagem Molecular/métodos , Software , Interface Usuário-Computador , Fluxo de TrabalhoRESUMO
Transient receptor potential channels (TRP channels) are cation selective transmembrane receptors with diverse structures, activation mechanisms and physiological functions. TRP channels act as cellular sensors for a plethora of stimuli, including temperature, membrane voltage, oxidative stress, mechanical stimuli, pH and endogenous, as well as, exogenous ligands, thereby illustrating their versatility. As such, TRP channels regulate various functions in both excitable and non-excitable cells, mainly by mediating Ca2+ homeostasis. Dysregulation of TRP channels is implicated in many pathologies, including cardiovascular diseases, muscular dystrophies and hyperalgesia. However, the importance of TRP channel expression, physiological function and regulation in chondrocytes and intervertebral disc (IVD) cells is largely unexplored. Osteoarthritis (OA) and degenerative disc disease (DDD) are chronic age-related disorders that significantly affect the quality of life by causing pain, activity limitation and disability. Furthermore, currently available therapies cannot effectively slow-down or stop progression of these diseases. Both OA and DDD are characterised by reduced tissue cellularity, enhanced inflammatory responses and molecular, structural and mechanical alterations of the extracellular matrix, hence affecting load distribution and reducing joint flexibility. However, knowledge on how chondrocytes and IVD cells sense their microenvironment and respond to its changes is still limited. In this review, we introduced six families of mammalian TRP channels, their mechanisms of activation, as well as, activation-driven cellular consequences. We summarised the current knowledge on TRP channel expression and activity in chondrocytes and IVD cells, as well as, the significance of TRP channels as therapeutic targets for the treatment of OA and DDD.
Assuntos
Degeneração do Disco Intervertebral/metabolismo , Artropatias/metabolismo , Osteoartrite/metabolismo , Canais de Potencial de Receptor Transitório/metabolismo , Animais , Condrócitos/citologia , Condrócitos/metabolismo , Expressão Gênica , Humanos , Disco Intervertebral/citologia , Disco Intervertebral/metabolismo , Degeneração do Disco Intervertebral/genética , Artropatias/genética , Osteoartrite/genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Canais de Potencial de Receptor Transitório/genéticaRESUMO
The recently developed radon film-badge makes it possible to measure radon indoors, in soil, in water and/or in aqueous media (e.g. mud). As a result of its wide response linearity, this monitor has been successfully used to measure radon in-water with concentrations from 10 to ~10 000 Bq/L. By exploiting the unique characteristics of this badge, a mini-survey has been carried out by Health Canada in which radon in water was measured from 12 private wells, as well as in tap water originating from the Ottawa River. Due to the widespread interest of different laboratories in using these passive monitors, laboratories were provided with plastic films to construct their own badges by using in-house CR-39 detectors. Monitors were then irradiated by a known radon concentration at the National Institute of Radiation Metrology (ENEA)'s radon chamber and sent back to each laboratory for processing and counting. Even though these laboratories have been using different etching- and counting-procedures, the film-badge responses varied only within ~12%.
Assuntos
Poluição do Ar em Ambientes Fechados/análise , Dosimetria Fotográfica , Cooperação Internacional , Monitoramento de Radiação/métodos , Radônio/análise , Poluentes Radioativos da Água/análise , Canadá , HumanosRESUMO
Galectins, a family of soluble ß-galactoside-binding proteins, are involved in the regulation of various cellular functions, which are essential for adaptive cellular stress responses (CSRs). Although expression patterns of galectins and galectin-binding glycans change during tissue development and cancer, the requirement and role of galectin networks in the CSRs are not completely understood. In this study, we report that the treatment of human promyelocytic HL-60 cells with stimuli mimicking hypoxia (CoCl2), inducing the endoplasmic reticulum stress (tunicamycin), and stimulating cell differentiation, result in stress-specific differential expression of galectin transcripts. In addition, we show that CoCl2 increases the expression of cell surface glycans recognized by both ß-galactoside- and GlcNAc-binding lectins. Thus, microenvironmental stress changes the glycobiological status of cells representing expression profiles of endogenous lectins and corresponding glycans. These findings introduce a novel classification of galectins in HL-60 cells, which suggests diverse functions of galectin members in CSRs.
Assuntos
Cobalto/farmacologia , Galectinas/genética , Galectinas/metabolismo , Tunicamicina/farmacologia , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Hipóxia Celular/efeitos dos fármacos , Tamanho Celular/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Células HL-60 , HumanosRESUMO
Research into Heliconius butterflies has made a significant contribution to evolutionary biology. Here, we review our understanding of the diversification of these butterflies, covering recent advances and a vast foundation of earlier work. Whereas no single group of organisms can be sufficient for understanding life's diversity, after years of intensive study, research into Heliconius has addressed a wide variety of evolutionary questions. We first discuss evidence for widespread gene flow between Heliconius species and what this reveals about the nature of species. We then address the evolution and diversity of warning patterns, both as the target of selection and with respect to their underlying genetic basis. The identification of major genes involved in mimetic shifts, and homology at these loci between distantly related taxa, has revealed a surprising predictability in the genetic basis of evolution. In the final sections, we consider the evolution of warning patterns, and Heliconius diversity more generally, within a broader context of ecological and sexual selection. We consider how different traits and modes of selection can interact and influence the evolution of reproductive isolation.
Assuntos
Adaptação Fisiológica , Evolução Biológica , Borboletas/fisiologia , Animais , Borboletas/genética , Fluxo Gênico , Isolamento Reprodutivo , Seleção Genética , Asas de AnimaisRESUMO
Intervertebral disc (IVD) disease, which is characterised by age-related changes in the adult disc, is the most common cause of disc failure and low back pain. The purpose of this study was to analyse the potential of the biologically active polyphenol epigallocatechin 3-gallate (EGCG) for the treatment of painful IVD disease by identifying and explaining its anti-inflammatory and anti-catabolic activity. Human IVD cells were isolated from patients undergoing surgery due to degenerative disc disease (n = 34) and cultured in 2D or 3D. An inflammatory response was activated by IL-1ß, EGCG was added, and the expression/activity of inflammatory mediators and pathways was measured by qRT-PCR, western blotting, ELISA, immunofluorescence and transcription factor assay. The small molecule inhibitor SB203580 was used to investigate the involvement of the p38 pathway in the observed effects. The analgesic properties of EGCG were analysed by the von Frey filament test in Sprague-Dawley rats (n = 60). EGCG significantly inhibited the expression of pro-inflammatory mediators and matrix metalloproteinases in vitro, as well as radiculopathic pain in vivo, most probably by modulation of the activity of IRAK-1 and its downstream effectors p38, JNK and NF-κB.
Assuntos
Catequina/análogos & derivados , Degeneração do Disco Intervertebral/tratamento farmacológico , Disco Intervertebral/efeitos dos fármacos , Neuralgia/tratamento farmacológico , Adulto , Animais , Catequina/farmacologia , Catequina/uso terapêutico , Células Cultivadas , Feminino , Humanos , Imidazóis/farmacologia , Inflamação/tratamento farmacológico , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Interleucina-1beta/farmacologia , Disco Intervertebral/metabolismo , Disco Intervertebral/patologia , MAP Quinase Quinase 4/metabolismo , Masculino , Metaloproteinases da Matriz/genética , Metaloproteinases da Matriz/metabolismo , Pessoa de Meia-Idade , NF-kappa B/genética , NF-kappa B/metabolismo , Piridinas/farmacologia , Radiculopatia/tratamento farmacológico , Ratos , Ratos Sprague-Dawley , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
The measurements of radon activity concentration carried out in residential houses of V4 countries (Hungary, Poland and Slovakia) show that radon levels in these countries considerably exceed the world average. Therefore, the new radon data and statistical analysis are required from these four countries. Each partner chose a region in their own country, where radon concentration in residential buildings was expected to be higher. The results of the survey carried out in the period from March 2012 to May 2012 show that radon concentrations are <200 Bq m(-3) in â¼87% of cases. However, dwellings with radon concentration â¼800 Bq m(-3) were found in Poland and Slovakia. It was also found that the distribution of radon frequency follows that of houses according to the year of their construction.
Assuntos
Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Habitação , Monitoramento de Radiação , Radônio/análise , Coleta de Dados , Humanos , Hungria , Polônia , EslováquiaRESUMO
A special set-up for continuous measurements of radon exhalation rate from soil is presented. It was constructed at Laboratory of Radiometric Expertise, Institute of Nuclear Physics Polish Academy of Sciences (IFJ PAN), Krakow, Poland. Radon exhalation rate was determined using the AlphaGUARD PQ2000 PRO (Genitron) radon monitor together with a special accumulation container which was put on the soil surface during the measurement. A special automatic device was built and used to raise and lower back onto the ground the accumulation container. The time of raising and putting down the container was controlled by an electronic timer. This set-up made it possible to perform 4-6 automatic measurements a day. Besides, some additional soil and meteorological parameters were continuously monitored. In this way, the diurnal and seasonal variability of radon exhalation rate from soil can be studied as well as its dependence on soil properties and meteorological conditions.
Assuntos
Poluentes Radioativos do Ar/análise , Poluentes Radioativos do Ar/química , Monitoramento de Radiação/instrumentação , Radioquímica , Radônio/análise , Radônio/química , Solo/química , Conceitos Meteorológicos , Fatores de TempoRESUMO
Radon measurements, as do any measurements, include errors in their readings. The relative values of such errors depend principally on the measurement methods used, the radon concentration to be measured and the duration of the measurements. Typical exposure times for radon surveys using passive detectors [nuclear track detectors, activated charcoal, electrostatic (E-perm), etc.)] may extend from a few days to months, whereas, in the case of screening methods utilising active radon monitors (AlphaGUARD, RAD7, EQF, etc.), the measurements may be completed quickly within a few hours to a few days. Thus, the latter may have relatively large error values, which affect the measurement accuracy significantly compared with the former measurements made over long time periods. The method presented in this paper examines the uncertainty of a short-term radon measurement as an estimate of the long-term mean and suggests a minimum measurement time to achieve a given margin of uncertainty of that estimate.
Assuntos
Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Monitoramento de Radiação/métodos , Radônio/análise , Japão , Modelos Estatísticos , Modelos Teóricos , Polônia , Reprodutibilidade dos Testes , Estações do Ano , Fatores de TempoRESUMO
Reducing the risk of Salmonella contamination in pet food is critical for both companion animals and humans, and its importance is reflected by the substantial increase in the demand for pathogen testing. Accurate and rapid detection of foodborne pathogens improves food safety, protects the public health, and benefits food producers by assuring product quality while facilitating product release in a timely manner. Traditional culture-based methods for Salmonella screening are laborious and can take 5 to 7 days to obtain definitive results. In this study, we developed two methods for the detection of low levels of Salmonella in pet food using real-time PCR: (i) detection of Salmonella in 25 g of dried pet food in less than 14 h with an automated magnetic bead-based nucleic acid extraction method and (ii) detection of Salmonella in 375 g of composite dry pet food matrix in less than 24 h with a manual centrifugation-based nucleic acid preparation method. Both methods included a preclarification step using a novel protocol that removes food matrix-associated debris and PCR inhibitors and improves the sensitivity of detection. Validation studies revealed no significant differences between the two real-time PCR methods and the standard U.S. Food and Drug Administration Bacteriological Analytical Manual (chapter 5) culture confirmation method.
Assuntos
Ração Animal/microbiologia , Contagem de Colônia Microbiana/métodos , Análise de Alimentos/instrumentação , Contaminação de Alimentos/análise , Reação em Cadeia da Polimerase em Tempo Real , Salmonella/isolamento & purificação , Animais , Qualidade de Produtos para o Consumidor , DNA Bacteriano/análise , Análise de Alimentos/métodos , Microbiologia de Alimentos , Fatores de TempoRESUMO
The method for the calculation of correction factors is presented, which can be used for the assessment of the mean annual radon concentration on the basis of 1-month or 3-month indoor measurements. Annual radon concentration is an essential value for the determination of the annual dose due to radon inhalation. The measurements have been carried out in 132 houses in Poland over a period of one year. The passive method of track detectors with CR-39 foil was applied. Four thermal-precipitation regions in Poland were established and correction factors were calculated for each region, separately for houses with and without basements.
Assuntos
Poluição do Ar em Ambientes Fechados/análise , Contaminação Radioativa do Ar/análise , Habitação , Radônio/análise , Polônia , Estações do AnoRESUMO
The possibility of using whey permeate as a raw material for the production of ethanol by continuous fermentation by using Kluyveromyces marxianus was examined. The ethanol formation was investigated as a function of the hydraulic retention time in a UASB reactor. The initial lactose concentration in permeate was 50.0 g L(-1). The hydraulic retention time supplied were 12, 24, 48 h and the daily ethanol formations were 4.46, 8.61, 7.73 g L(-1), respectively. The yield coefficient of ethanol was 0.089 g ethanol g(-1) lactose when the hydraulic retention time was 12 h and raised to 0.325 g g(-1) when the hydraulic retention time was as long as 48 h. The results indicated that in ethanol fermentation the hydraulic retention time should be 24 h to obtain high rates of ethanol formation and to avoid product inhibition.
Assuntos
Reatores Biológicos/microbiologia , Etanol/metabolismo , Kluyveromyces/metabolismo , Leite/metabolismo , Eliminação de Resíduos Líquidos/métodos , Anaerobiose , Animais , Fermentação , Indústria Alimentícia , Concentração de Íons de Hidrogênio , Lactose/metabolismo , Proteínas do Leite , Fatores de Tempo , Proteínas do Soro do LeiteRESUMO
Hybrid zones have yielded considerable insight into many evolutionary processes, including speciation and the maintenance of species boundaries. Presented here are analyses from a hybrid zone that occurs among three salamanders -Plethodon jordani, Plethodon metcalfi and Plethodon teyahalee- from the southern Appalachian Mountains. Using a novel statistical approach for analysis of non-clinal, multispecies hybrid zones, we examined spatial patterns of variation at four markers: single-nucleotide polymorphisms (SNPs) located in the mtDNA ND2 gene and the nuclear DNA ILF3 gene, and the morphological markers of red cheek pigmentation and white flecks. Concordance of the ILF3 marker and both morphological markers across four transects is observed. In three of the four transects, however, the pattern of mtDNA is discordant from all other markers, with a higher representation of P. metcalfi mtDNA in the northern and lower elevation localities than is expected given the ILF3 marker and morphology. To explore whether climate plays a role in the position of the hybrid zone, we created ecological niche models for P. jordani and P. metcalfi. Modelling results suggest that hybrid zone position is not determined by steep gradients in climatic suitability for either species. Instead, the hybrid zone lies in a climatically homogenous region that is broadly suitable for both P. jordani and P. metcalfi. We discuss various selective (natural selection associated with climate) and behavioural processes (sex-biased dispersal, asymmetric reproductive isolation) that might explain the discordance in the extent to which mtDNA and nuclear DNA and colour-pattern traits have moved across this hybrid zone.
Assuntos
Clima , Ecossistema , Hibridização Genética , Urodelos/genética , Animais , Núcleo Celular/genética , DNA Mitocondrial/genética , Modelos Lineares , Modelos Genéticos , Dados de Sequência Molecular , North Carolina , Pigmentação , Polimorfismo de Nucleotídeo Único , Análise Espacial , Tennessee , Urodelos/anatomia & histologiaRESUMO
The present research was an investigation of the influence of an innovative design of reactor filled with polyethylene (PE) granulate on model dairy wastewater treatment efficiency under anaerobic conditions compared to that obtained in a typical UASB reactor. The experiment was conducted at laboratory scale. An innovative reactor was designed with the reaction chamber inclined 30 degrees in relation to the ground with upward waste flow and was filled with PE granular material. Raw model dairy wastewater was fed to two anaerobic reactors of different design at the organic loading rate of 4 kg COD m(-3)d(-1). Throughout the experiment, a higher removal efficiency of organic compounds was observed in the reactor with an innovative design and it was higher by 7.1% on average than in the UASB reactor. The total suspended solids was lower in the wastewater treated in the anaerobic reactor with the innovative design. Applying a PE granulated filling in the chamber of the innovative reactor contributed to an even distribution of sludge biomass in the reactor, reducing washout of anaerobic sludge biomass from the reaction chamber and giving a higher organic compounds removal efficiency.