Effects on the accelerating electron bunches due to the presence of sulfur hexafluoride or air in the linac waveguide

Sulfur hexafluoride gas (SF6) is used as a dielectric insulator in the acceleration process of certain medical linear accelerator waveguides. Nevertheless, some innovative development and investigation cases require intervention in the linear accelerator or, specifically, on the waveguide, which could affect the sealing of the device. In this regard, vacuum sealing systems can be compromised, affecting the properties of the radiation beams produced. The presence of sulfur hexafluoride or air inside the VARIAN 6/100 waveguide was investigated under different pressure conditions and non-uniform electric fields, adapting Monte Carlo simulation techniques for modeling radiation transport coupled with electric fields. Obtained results indicated the suitability of the proposed approach, while comparisons with theoretical approaches and experimental evidence supported the model's consistency.

Microplastic concentration, distribution and dynamics along one of the largest Mediterranean-climate rivers: A whole watershed approach

Microplastics (MPs) have been recognized as one of the most ubiquitous environmental pollutants globally. They have been found in all ecosystems studied to date, threatening biological diversity, ecosystem functioning and human health. The present study aimed to elucidate the environmental and anthropogenic drivers of MP dynamics in the whole catchment of the Biobío river, one of the largest rivers in South America. MP concentration and characteristics were analysed in 18 sites subjected to different sources of pollution and other human-related impacts. The sampling sites were classified in relation to altitudinal zones (highland, midland and lowland) and ecosystem types (fluvial and reservoir), and different water and territorial environmental variables were further collated and considered for analysis. Seven types of microplastic polymers were identified in the samples analysed, with a catchment mean (±SE) MP concentration of 22 ± 0.4 particles m^-3, and MP presence being significantly higher in lowlands (26 ± 2 particle m^-3) and in reservoirs (42 ± 14 particle m^-3). The most abundant type of MP was fragments (84%), with a mean concentration of 37 ± 6 particles m^-3. Overall, MP concentrations were low compared to those found in other studies, with a strong influence of human population size.

Fricke gel xylenol orange dosimeter layers for stereotactic radiosurgery: A preliminary approach

Investigations regarding the feasibility, reliability, and accuracy of Fricke gel dosimeter layers for stereotactic radiosurgery are presented. A representative radiosurgery plan consisting of two targets has been investigated. Absorbed dose distributions measured using radiochromic films and gelatin Fricke Gel dosimetry in layers have been compared with dose distributions calculated by using a treatment planning system and Monte Carlo simulations. The different dose distributions have been compared by means of the gamma index demonstrating that gelatin Fricke gel dosimeter layers showed agreements of 100%, 100%, and 93%, with dose and distance tolerances of 2% and 2 mm, with respect to film dosimetry, treatment planning system and Monte Carlo simulations, respectively. The capability of the developed system for three-dimensional dose mapping was shown, obtaining promising results when compared with well-established dosimetry methods. The obtained results support the viability of Fricke gel dosimeter layers analyzed by optical methods for stereotactic radiosurgery.

Impacts of detritivore diversity loss on instream decomposition are greatest in the tropics

The relationship between detritivore diversity and decomposition can provide information on how biogeochemical cycles are affected by ongoing rates of extinction, but such evidence has come mostly from local studies and microcosm experiments. We conducted a globally distributed experiment (38 streams across 23 countries in 6 continents) using standardised methods to test the hypothesis that detritivore diversity enhances litter decomposition in streams, to establish the role of other characteristics of detritivore assemblages (abundance, biomass and body size), and to determine how patterns vary across realms, biomes and climates. We observed a positive relationship between diversity and decomposition, strongest in tropical areas, and a key role of abundance and biomass at higher latitudes. Our results suggest that litter decomposition might be altered by detritivore extinctions, particularly in tropical areas, where detritivore diversity is already relatively low and some environmental stressors particularly prevalent.

It is unclear whether stream detritivore diversity enhances decomposition across climates. Here the authors manipulate litter diversity and examine detritivore assemblages in a globally distributed stream litterbag experiment, finding a positive diversity-decomposition relationship stronger in tropical streams, where detritivore diversity is lower.

Water quality of streams associated with artisanal gold mining; Suárez, Department of Cauca, Colombia

Gold mining is one of the major problems of contamination of hydric resources in Colombia, this practice generates a high impact on water quality due to the accumulation of waste during its process. In this study water quality was evaluated in five natural stream beds corresponding to four streams with gold mining operations and one in the Cauca River, taking samples before the water inlet and after the outlet in each operation in the streams of Dios Te Dé, Tamboral, Piedra Imán, and Lorenzo affected by artisanal gold mining labor, which drain into the Salvajina Reservoir on the Cauca River in the municipality of Suárez Cauca, Colombia. Characterization of water bodies in the streams was carried out applying contamination indices of Colombia. The IDEAM protocol was used as guide to monitor the water currents. Samples were taken in 15 stations in the natural stream beds with operations and a sampling station on the Cauca River after the reservoir in these lotic ecosystems, during three periods; two from 2018 and one from 2019. The range of the contamination indices according to the environmental variables were considered. Results show that the contaminants associated with TSS, TUR, and Hg are high in the sampling stations in the output of the operations and the sampling stations of the streams with influence on the operations (T3, T4, I2, I3, D2, and D5). The water quality score according to the ICA IDEAM index varied between acceptable and regular in the different sampling stations. However the Hg concentration in sampling station C1 of the Cauca River is due to contributions from the operations in the amalgamation process. This requires strategic interventions by the communities, miners, operation owners, and control organisms as the Regional Autonomous Corporation of Cauca (CRC) and the Ministry of Environment and Sustainable Development (MADS) to minimize the negative impacts on the hydric resource and ecosystemic services associated with this resource.

Latitude dictates plant diversity effects on instream decomposition

Running waters contribute substantially to global carbon fluxes through decomposition of terrestrial plant litter by aquatic microorganisms and detritivores. Diversity of this litter may influence instream decomposition globally in ways that are not yet understood. We investigated latitudinal differences in decomposition of litter mixtures of low and high functional diversity in 40 streams on 6 continents and spanning 113° of latitude. Despite important variability in our dataset, we found latitudinal differences in the effect of litter functional diversity on decomposition, which we explained as evolutionary adaptations of litter-consuming detritivores to resource availability. Specifically, a balanced diet effect appears to operate at lower latitudes versus a resource concentration effect at higher latitudes. The latitudinal pattern indicates that loss of plant functional diversity will have different consequences on carbon fluxes across the globe, with greater repercussions likely at low latitudes.

Monte Carlo study of a convergent X-ray beam for high resolution X-ray fluorescence imaging

The traditional X-ray tube design is built upon the impact of energetic electrons on high atomic number absorbers producing the X-ray output, consisting of photons due to Bremsstrahlung and fluorescence. Typically, electrons current hits the target within a limited area of a few millimeters square stopping the electrons, which lose their energy and produce the X rays constituting an inherently divergent beam. This geometrical property of traditional X-ray beams is responsible for several undesirable effects when trying to optimize applications requiring high incident fluence spatial concentration, like X-ray fluorescence imaging. This work presents a Monte Carlo study about a novel X-ray tube design, based on a cylindrical target that is capable of producing a convergent X-ray beam aimed at improving overall performance and spatial resolution in certain applications, like X-ray fluorescence imaging. Main design characteristics for relevant parts, like target/anode, filter, and collimator, have been carefully investigated by means of Monte Carlo simulation using two independent codes: FLUKA and PENELOPE. The obtained results suggest the feasibility of the proposed design remarking that high fluence concentration can be achieved, which can be particularly useful for further applications, like tumor targeting by X-ray fluorescence imaging by means of high atomic number nanoparticle infusion, as reported in this work.

Developmental instability is associated with estrogenic endocrine disruption in the Chilean native fish species, Trichomycterus areolatus

Endocrine disrupting compounds (EDCs) are widespread contaminants that alter the normal functioning of the endocrine system. While they cause dysfunctions in essential biological processes, it is unclear whether EDCs also impact developmental stability. In the present study, we investigated the occurrence of estrogenic endocrine disrupting compounds in a small watershed of south-central Chile impacted by anthropogenic activities. Then, we assessed their relationship with internal levels of estrogenic active compounds and fluctuating asymmetry (FA), a proxy of developmental stability in organisms with bilateral symmetry, in a native fish species (Trichomycterus areolatus). Yeast estrogenic screen assays were performed to measure estrogenic activity in river sediments and in male fish tissues collected from 17 sites along the Chillán watershed, and geometric morphometrics used to estimate fluctuating asymmetry based on the shapes of 248 fish skulls. Estrogenic activity was detected both in sediments and male fish tissues at concentrations of up to 1005 ng and 83 ng 17β-estradiol equivalent/kg dw, respectively. No significant correlation was found between the two. However, fish tissue estrogenicity, water temperature and dissolved oxygen explained >80% of the FA population variation. By showing a significant relationship between estrogenic activity and FA of T. areolatus, our results indicate that developmental stability can be altered by estrogenic endocrine disruption, and that FA can be a useful indicator of sub-lethal stress in T. areolatus populations.

Patterns of richness of freshwater mollusks from Chile: predictions of its distribution based on null models

The freshwater mussels from Chile are characterized by a high percentage of endemism and a fragmented latitudinal diversity, which has been attributed to the features and geomorphological history sculpted by the hydrographic basins. In this work, a set of hypothesis under a macroecological approach is addressed, with the aim to explore environmental, topographic and hydrological factors that define the latitudinal distribution of this mussel group. In order to achieve this goal, Rapoport’s rule, geometrics limits and co-ocurrence were evaluated. In addition, we analyze the source and sink hypotheses through the nested analysis. We observed a noticeable mid-domain effect (MDE), where a major richness than expected was randomly observed between 40 and 41°S. The results revealed that the distribution pattern was not concordant with Rapoport’s rule (r = 0.123; p = 0.128). Regarding to historical dynamic of the distribution, the results show a significant nestedness pattern, suggesting a source-sink dynamic, that is, poorer communities are a subset of richer communities in species. According to the co-occurrence analysis, an aggregate pattern existed, suggesting potential regulatory mechanisms. The specific richness pattern is explained by the variable seasonality of the temperature with a variance percentage explained of 35%. The full model indicated that variables which characterize the heterogeneity of habitat (i.e. range, Shannon), water availability (i.e., precipitation, density of water bodies) and topography (i.e., altitude area available) jointly explain 40% of the variability of the observed richness. This study shows that the geographical distribution of mollusc richness is mainly explained by mainly climatic and topographical environmental components, as well as by the source-sink dynamics.

Simulating rewetting events in intermittent rivers and ephemeral streams: A global analysis of leached nutrients and organic matter

Climate change and human pressures are changing the global distribution and the extent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico-chemical changes (preconditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experimentally simulated, under standard laboratory conditions, rewetting of leaves, riverbed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative characteristics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dissolved substances during rewetting events (56%-98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contributed most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached OM. The opposite pattern was found in the arid zone. Environmental variables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached substances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying events.

Improvement of appropriate pharmacological prophylaxis in hospitalised cancer patients with a multiscreen e-alert system: a single-centre experience

PURPOSE

Thromboprophylaxis use among medical inpatients, including cancer patients, is suboptimal. We aimed to evaluate the impact of a novel multiscreen version (v2.0) of an e-alert system for VTE prevention in hospitalised cancer medical patients compared to the original software.

METHODS

Prospective study including 989 consecutive adult cancer patients with high-risk of VTE. Patients were followed-up 30 days post-discharge. Two periods were defined, according to the operative software.

RESULTS

E-alert v2.0 was associated with an increase in the use of LMWH prophylaxis (65.5% vs. 72.0%); risk difference (95% CI) 0.064 (0.0043-0.12). Only 16% of patients in whom LMWH prophylaxis was not prescribed lacked a contraindication. No significant differences in the rates of VTE (2.9% vs. 3.2%) and major bleeding (2.7% vs. 4.0%) were observed.

CONCLUSIONS

E-alert v2.0 further increased the use of appropriate thromboprophylaxis in hospitalised cancer patients, although was not associated with a reduction in VTE incidence.

Development of the Nutrition and Functionality Assessment (NFA) among Older Adults in Japan

OBJECTIVE

Develop and evaluate the feasibility and validity of the Nutrition and Functionality Assessment (NFA) which identifies "target" older adults who could benefit from a personalized program following evaluation of their nutrition status and physical functionality.

DESIGN

Cross-sectional study.

SETTING

Community and geriatric day-care centers and university in Japan.

PARTICIPANTS

267 older adults aged 65-90.

MEASUREMENTS

The "target" individuals were screened based on gait speed (0.6-1.5 m/s). Nutrition (Mini Nutrition Assessment-short form and protein intake), strength (30s chair sit-to-stand and hand-grip strength) and endurance (6-minute walk) were assessed. Physical activity was monitored using a tri-axil accelerometer for a week. Fried frailty phenotype was also assessed.

RESULTS

Out of 267 individuals, 185 (69%) had gait speed between 0.6-1.5 m/s, corresponding to our "target" group from which, 184 (95%) completed the nutrition and physical functionality assessments with the physical activity monitoring. The NFA was completed in approximately 30 minutes. No adverse events directly due to the NFA were reported. NFA physical functionality and global scores were significantly related to frailty phenotype but nutrition score was not related to frailty phenotype.

CONCLUSION

The study demonstrated that the NFA is a safe and feasible tool to screen target older adults and simultaneously evaluate their nutritional status and physical functionality. Validity of the NFA was partially confirmed by the significant association of the global and physical functionality scores with frailty phenotype. More studies are required to validate and maximize the applicability of the NFA in communities and institutions in Japan and elsewhere.

Seasonal drought effects on the water quality of the Biobío River, Central Chile

Quantifying the effect of droughts on ecosystem functions is essential to the development of coastal zone and river management under a changing climate. It is widely acknowledged that climate change is increasing the frequency and intensity of droughts, which can affect important ecosystem services, such as the regional supply of clean water. Very little is understood about how droughts affect the water quality of Chilean high flow rivers. This paper intends to investigate the effect of an, recently identified, unprecedented drought in Chile (2010-2015), on the Biobío River water quality, (36°45'-38°49' S and 71°00'-73°20' W), Central Chile. This river is one of the largest Chilean rivers and it provides abundant freshwater. Water quality (water temperature, pH, dissolved oxygen, electrical conductivity, biological oxygen demand, total suspended solids, chloride, sodium, nutrients, and trace metals), during the drought (2010-2015), was compared with a pre-drought period (2000-2009) over two reaches (upstream and downstream) of the river. Multivariate analysis and seasonal Mann-Kendall trend analyses and a Theil-Sen estimator were employed to analyze trends and slopes of the reaches. Results indicated a significant decreased trend in total suspended solids and a slightly increasing trend in water temperature and EC, major ions, and trace metals (chrome, lead, iron, and cobalt), mainly in summer and autumn during the drought. The reduced variability upstream suggested that nutrient and metal concentrations were more constant than downstream. The results evidenced, due to the close relationship between river discharge and water quality, a slightly decline of the water quality downstream of the Biobío River during drought period, which could be attenuated in a post-drought period. These results displayed that water quality is vulnerable to reductions in flow, through historical and emerging solutes/contaminants and induced pH mobilization. Consequently, seasonal changes and a progressive reduction of river flow affect the ecosystem functionality in this key Chilean river. The outcomes from this research can be used to improve how low flow conditions and the effects of a reduction in the river volume and discharge are assessed, which is the case under the scenario of more frequent drought periods.

Pollution Assessment of the Biobío River (Chile): Prioritization of Substances of Concern Under an Ecotoxicological Approach

The water demand for human activities is rapidly increasing in developing countries. Under these circumstances, preserving aquatic ecosystems should be a priority which requires the development of quality criteria. In this study we perform a preliminary prioritization of the risky substances based on reported ecotoxicological studies and guidelines for the Biobío watershed (Central Chile). Our specific aims are (1) reviewing the scientific information on the aquatic pollution of this watershed, (2) determining the presence and concentration of potential toxic substances in water, sediment and effluents, (3) searching for quality criteria developed by other countries for the selected substances and (4) prioritizing the most risky substances by means of deterministic ecotoxicological risk assessment. We found that paper and mill industries were the main sources of point pollution, while forestry and agriculture were mostly responsible for non-point pollution. The most risky organic substances in the water column were pentachlorophenol and heptachlor, while the most relevant inorganic ones were aluminum, copper, unionized ammonia and mercury. The most risky organic and inorganic substances in the sediment were phenanthrene and mercury, respectively. Our review highlights that an important effort has been done to monitor pollution in the Biobío watershed. However there are emerging pollutants and banned compounds-especially in sediments-that require to be monitored. We suggest that site-specific water quality criteria and sediment quality criteria should be developed for the Biobío watershed, considering the toxicity of mixtures of chemicals to endemic species, and the high natural background level of aluminum in the Biobío.

Saturated Fatty Acid Analogues of Cell-Penetrating Peptide PepFect14: Role of Fatty Acid Modification in Complexation and Delivery of Splice-Correcting Oligonucleotides

Modifying cell-penetrating peptides (CPPs) with fatty acids has long been used to improve peptide-mediated nucleic acid delivery. In this study we have revisited this phenomenon with a systematic approach where we developed a structure-activity relationship to describe the role of the acyl chain length in the transfection process. For that we took a well-studied CPP, PepFect14, as the basis and varied its N-terminal acyl chain length from 2 to 22 carbons. To evaluate the delivery efficiency, the peptides were noncovalently complexed with a splice-correcting oligonucleotide (SCO) and tested in HeLa pLuc705 reporter cell line. Our results demonstrate that biological splice-correction activity emerges from acyl chain of 12 carbons and increases linearly with each additional carbon. To assess the underlying factors regarding how the transfection efficacy of these complexes is dependent on hydrophobicity, we used an array of different methods. For the functionally active peptides (C12-22) there was no apparent difference in their physicochemical properties, including complex formation efficiency, hydrodynamic size, and zeta potential. Moreover, membrane activity studies with peptides and their complexes with SCOs confirmed that the toxicity of the complexes at higher molar ratios is mainly caused by the free fraction of the peptide which is not incorporated into the peptide/oligonucleotide complexes. Finally, we show that the increase in splice-correcting activity correlates with the ability of the complexes to associate with the cells. Collectively these studies lay the ground work for how to design highly efficient CPPs and how to optimize their oligonucleotide complexes for lowest toxicity without losing efficiency.

Biotic and abiotic variables influencing plant litter breakdown in streams: a global study

Plant litter breakdown is a key ecological process in terrestrial and freshwater ecosystems. Streams and rivers, in particular, contribute substantially to global carbon fluxes. However, there is little information available on the relative roles of different drivers of plant litter breakdown in fresh waters, particularly at large scales. We present a global-scale study of litter breakdown in streams to compare the roles of biotic, climatic and other environmental factors on breakdown rates. We conducted an experiment in 24 streams encompassing latitudes from 47.8° N to 42.8° S, using litter mixtures of local species differing in quality and phylogenetic diversity (PD), and alder (Alnus glutinosa) to control for variation in litter traits. Our models revealed that breakdown of alder was driven by climate, with some influence of pH, whereas variation in breakdown of litter mixtures was explained mainly by litter quality and PD. Effects of litter quality and PD and stream pH were more positive at higher temperatures, indicating that different mechanisms may operate at different latitudes. These results reflect global variability caused by multiple factors, but unexplained variance points to the need for expanded global-scale comparisons.

Obesity and Muscle Weakness as Risk Factors for Mobility Limitation in Community-Dwelling Older Japanese Women: A Two-Year Follow-Up Investigation

OBJECTIVES

To examine the combined association of obesity and low muscle strength with mobility limitation in older adults.

DESIGN, SETTING AND PARTICIPANTS

This two-year follow-up longitudinal study included pooled data from 283 older community-dwelling Japanese women without mobility limitations who were 65 to 87 years of age (mean age 72.2 ± 5.0 years).

MEASUREMENTS

Muscle strength was measured by hand-grip strength (HGS). The participants were categorized by HGS (high muscle strength: HGS ≥19.6 kg, low muscle strength: HGS <19.6 kg) and body mass index (BMI) (obese: BMI ≥25 kg/m2, normal weight: BMI <25 kg/m2). The main outcome was mobility limitation, assessed by a self-reported questionnaire (difficulty walking one-half mile or climbing 10 steps without resting). Multivariate logistic regression analysis was performed to determine the combined effect of HGS and BMI on mobility limitation, adjusting for age, exercise habits, medications, and knee pain.

RESULTS

During the follow-up period, 82 of 283 participants (29.0%) developed mobility limitation. The adjusted odds ratios (95% confidence interval) for the incidence of mobility limitation were 1.53 (0.86-2.73) and 2.05 (1.08-3.91) in the obese and low muscle strength groups, respectively. Obesity combined with low muscle strength exhibited a significant and strong association with mobility limitation (odds ratio: 3.88, 1.08-13.91) compared with participants with normal weight and high muscle strength.

CONCLUSION

Among community-dwelling older Japanese women, obesity alone was not associated with the incidence of mobility limitation, but when combined with low muscle weakness, the risk of developing mobility limitation was 3.9-fold greater than for the reference group.

Anatomy of the fetal membranes using optical coherence tomography: part 1

INTRODUCTION

In vitro studies on the structure of human fetal membranes have involved light or electron microscopy with fixation, dehydration, and staining. Recently, optical coherence tomography (OCT), an imaging technology, has provided high-resolution cross-sectional images of living biological tissues, with a penetration of 2-3 mm. We evaluated the use of this technology to examine the histologic features of human fetal membranes immediately after delivery.

METHODS

Samples of fetal membranes of ten patients undergoing cesarean deliveries (four uncomplicated pregnancies, four with preeclampsia, and two with chorioamnionitis) and eight patients undergoing vaginal deliveries (six uncomplicated pregnancies and two with chorioamnionitis) were collected immediately after delivery. Samples were stretched across customized disks, rinsed, and analyzed using a time-domain OCT imaging system. Following OCT scanning, the samples were placed in formalin for histologic study. The OCT images were compared to histologic images of common human fetal membrane features.

RESULTS

We were able to delineate the layers of the fetal membranes using bench-top time-domain OCT. The system was able to image histologic features of the fetal membranes, such as microscopic chorionic pseudocysts, ghost villi, meconium stained membranes, and chorioamnionitis. The OCT images corresponded with the histologic findings.

DISCUSSION

This feasibility study demonstrates the potential of OCT technology for real-time assessment of human fetal membranes and may provide clinically useful information at delivery.

Retained asymptomatic third molars and risk for second molar pathology

Prophylactic extraction of unerupted asymptomatic third molars is the most common oral surgery procedure in the United States. However, limited evidence exists to justify its costs and associated morbidity. We analyzed data collected over 25 years from 416 adult men enrolled in the Veterans Affairs Dental Longitudinal Study to evaluate the association of retained asymptomatic third molars with risk of adjacent second molar pathology (caries and/or periodontitis), based on third molar status (i.e., absent, erupted, or unerupted). Unerupted molars were further categorized as either "soft tissue" or "bony" impacted. We found that the lowest prevalence and incidence of second molar pathology occurred when the adjacent third molar was absent. The presence of a third molar that was soft tissue impacted increased the risk of incident second molar pathology 4.88-fold (95% confidence interval: 2.62, 9.08). Having an erupted or "bony" impacted third molar increased the risk of incident second molar pathology by 1.74 (95% confidence interval: 1.34, 2.25) and 2.16 (95% confidence interval: 1.56, 2.99), respectively. The retention of third molars is associated with increased risk of second molar pathology in middle-aged and older adult men.

Solubilidad proteica, contenido de mioglobina, color y pH de la carne de pollo, gallina y codorniz

Las proteínas de la carne son responsables de diversas características de sus productos derivados. La solubilidad de las proteínas cárnicas puede ser un índice de otras propiedades funcionales importantes para el procesamiento de la carne, como la emulsificación, mientras que el contenido de mioglobina influye en su color. Con el objeto de evaluar la solubilidad de las proteínas sarcoplásmicas y miofibrilares así como el contenido de mioglobina en la carne de aves, se obtuvieron canales de pollo, gallina y codorniz a partir de mataderos comerciales; se aplicó un diseño completamente aleatorizado con arreglo factorial 3x2, siendo los factores: tipo de ave (pollo, gallina y codorniz) y porción corporal (carne de pechuga y carne de pierna) generándose seis tratamientos, tres repeticiones por tratamiento. Se observó interacción de los factores para: Luminosidad (L), grado de color rojo (a), pH, extracción de proteínas sarcoplásmicas y proteínas miofibrilares. El contenido de mioglobina fue afectado tanto por la porción corporal como por el tipo de ave, siendo superior en la pierna en comparación con la pechuga (0,99 y 0,47 mg/g carne, respectivamente), y siendo la codorniz la que presenta el mayor valor (1,13 mg/g) y el pollo el menor (0,37 mg/g). En todos los casos el pH de la carne de pierna fue superior al pH de la pechuga. En la extracción de las proteínas del sarcoplasma hubo una tendencia a obtener un mayor porcentaje de la pechuga, mientras que las proteínas miofibrilares se obtuvieron en mayor proporción en la porción de la pierna. La información generada sobre las características de la carne de estas aves es novedosa en Venezuela y puede contribuir a explicar el comportamiento de estas materias primas durante su procesamiento.