Predicting feed efficiency of Angus steers using the gastrointestinal microbiome.

Microbial composition of the gastrointestinal tracts is an important factor affecting the variation in feed efficiency in ruminants. Several studies have investigated the composition of the ruminal and fecal microbiotas, as well as their impacts on feed efficiency and digestion. In addition, next-generation DNA sequencing techniques have allowed us to gain a better understanding of such microbiomes. In this study, the beef cattle microbiome data were analyzed using both a multivariate and a univariate approach and the results were compared. Moreover, a statistical procedure to classify calves in two groups with extreme Residual Feed Intake (RFI) values, using their microbiota profile, was developed. Both fecal and ruminal samples were collected from 63 Angus steers at two different time points for evaluation of their microbiomes: at the beginning and at the end of the feedlot. An additional fecal sample was collected at weaning. A total of 149 and 119 bacterial families (BFs) were retrieved from the ruminal and fecal samples, respectively. A Canonical Discriminant Analysis (CDA) was used to investigate whether BFs were able to distinguish between rumen and fecal samples. A sub-sample of 28 steers was divided in two groups based on their feed efficiency status: positive or negative for RFI. Fecal samples collected at weaning were used to assign the positive and negative RFI animals to their corresponding groups using both Stepwise Discriminant Analysis and CDA. Results revealed that CDA was able to distinguish between rumen and fecal samples. Peptostreptococcaceae was the family most associated with the fecal samples, whereas Prevotellaceae the most associated with the ruminal samples. The CDA using 19 BFs selected from the stepwise was able to correctly assign all animals to the proper RFI groups (negative or positive). Rhizobiaceae was the family most associated with negative RFI, whereas Comamonadacea was the family most linked with positive RFI. The results from this study showed that the multivariate approach can be used to improve microbiome data analysis, as well as to predict feed efficiency in beef cattle using information derived from the fecal microbiome.

How Long Does Contouring Really Take? Results of the Royal College of Radiologists Contouring Surveys.

AIMS: The success and safety of modern radiotherapy relies on accurate contouring. Understanding the time taken to complete radiotherapy contours is critical to informing workforce planning and, in the context of a workforce shortfall, advocating for investment in technology and multi-professional skills mix. We aimed to quantify the time taken to delineate target volumes for radical radiotherapy. MATERIALS AND METHODS: The Royal College of Radiologists circulated two electronic surveys via email to all clinical oncology consultants in the UK. The individual case survey requested anonymous data regarding the next five patients contoured for radical radiotherapy. The second survey collected data on respondents' usual practice in radiotherapy contouring. RESULTS: The median time to contour one radiotherapy case was 85 minutes (IQR = 50-131 minutes). Marked variability between and within tumour sites was evident: paediatric cancers took the most time (median = 210 minutes, IQR = 87.5 minutes), followed by head and neck and gynaecological cancers (median = 120 minutes, IQR = 71 and 72.5 minutes respectively). Breast cancer contouring required the least time (median = 43 minutes, IQR = 60 minutes). Radiotherapy technique, inclusion of nodes and 4D CT planning were associated with longer contouring times. A non-medical professional was involved in contouring in 65% of cases, but clinical oncology consultants were involved in target volume delineation in 90% of cases, and OARs in 74%. Peer review took place in 46% of cases with 56% of consultants reporting no time for peer review in their job plan. CONCLUSION: Contouring for radical radiotherapy is complex and time-consuming, and despite increasing involvement of non-medical professionals, clinical oncology consultants remain the primary practitioners. Peer review practice is variable and time is often a limiting factor. Many factors influence the time required for contouring, and departments should take these factors and the need for peer-review into account when developing job plans.

Spatial accumulation of flood-driven riverside litter in two Northern Atlantic Rivers.

The escalation of litter accumulation in aquatic environments is recognized as an emerging global concern. Although rivers represent the main conduits for land-based waste into the oceans, the spatial dynamics of litter accumulation in these systems remain poorly investigated, especially after hydro-climatic extreme events. Floods have been identified as major drivers of litter mobilization, including macroplastics, within rivers. However, predicting flood-induced litter accumulation along riverbanks is complex due to the cumulative interplay of multiple environmental (geomorphological and riparian) and anthropogenic factors. Using empirical data collected from 14 stream reaches in two Northern Atlantic rivers in Portugal, our study evaluates which factors, among geomorphological, riparian, and anthropogenic descriptors, best drive riverside litter accumulation after floods. Taking into account the longitudinal gradient and the spatial heterogeneity of the studied reaches, our study enhances how the accumulation and characteristics (type, size) of riverside litter vary across a rural-urban continuum. Our model reveals that the combination of the human population density and the stream slope at river reach showed the highest explanatory power for the accumulation of riverside litter. Our findings indicate that litter tends to be retained close to the source, even under flood conditions. We also found that the structure of riparian vegetation showed low explanatory power for litter accumulation. However, riparian trapping could be influenced by litter input (density and type) which varies with anthropogenic activities. This work highlights the importance of gathering field data to identify critical areas of riverside litter accumulation within river basins. Our findings can further support environmental managers in designing and implementing effective cleanup campaigns and implementing plastic recovery strategies at specific areas. Nevertheless, it is crucial to enhance coordinated efforts across the entire value chain to reduce plastic pollution, promote innovative approaches for plastic litter valorization, and establish effective prevention pathways.

Invited review: "Probiotic" approaches to improving dairy production: Reassessing "magic foo-foo dust".

The gastrointestinal microbial consortium in dairy cattle is critical to determining the energetic status of the dairy cow from birth through her final lactation. The ruminant's microbial community can degrade a wide variety of feedstuffs, which can affect growth, as well as production rate and efficiency on the farm, but can also affect food safety, animal health, and environmental impacts of dairy production. Gut microbial diversity and density are powerful tools that can be harnessed to benefit both producers and consumers. The incentives in the United States to develop Alternatives to Antibiotics for use in food-animal production have been largely driven by the Veterinary Feed Directive and have led to an increased use of probiotic approaches to alter the gastrointestinal microbial community composition, resulting in improved heifer growth, milk production and efficiency, and animal health. However, the efficacy of direct-fed microbials or probiotics in dairy cattle has been highly variable due to specific microbial ecological factors within the host gut and its native microflora. Interactions (both synergistic and antagonistic) between the microbial ecosystem and the host animal physiology (including epithelial cells, immune system, hormones, enzyme activities, and epigenetics) are critical to understanding why some probiotics work but others do not. Increasing availability of next-generation sequencing approaches provides novel insights into how probiotic approaches change the microbial community composition in the gut that can potentially affect animal health (e.g., diarrhea or scours, gut integrity, foodborne pathogens), as well as animal performance (e.g., growth, reproduction, productivity) and fermentation parameters (e.g., pH, short-chain fatty acids, methane production, and microbial profiles) of cattle. However, it remains clear that all direct-fed microbials are not created equal and their efficacy remains highly variable and dependent on stage of production and farm environment. Collectively, data have demonstrated that probiotic effects are not limited to the simple mechanisms that have been traditionally hypothesized, but instead are part of a complex cascade of microbial ecological and host animal physiological effects that ultimately impact dairy production and profitability.

Schizochytrium sp. and lactoferrin supplementation alleviates Escherichia coli K99-induced diarrhea in preweaning dairy calves.

Calf diarrhea, a common disease mainly induced by Escherichia coli infection, is one of the main reasons for nonpredator losses. Hence, an effective nonantibacterial approach to prevent calf diarrhea has become an emerging requirement. This study evaluated the microalgae Schizochytrium sp. (SZ) and lactoferrin (LF) as a nutrient intervention approach against E. coli O101:K99-induced preweaning calve diarrhea. Fifty 1-d-old male Holstein calves were randomly divided into 5 groups (n = 10): (1) control, (2) blank (no supplement or challenge), (3) 1 g/d LF, (4) 20 g/d SZ, or (5) 1 g/d LF plus 20 g/d SZ (LFSZ). The experimental period lasted 14 d. On the morning of d 7, calves were challenged with 1 × 1011 cfu of E. coli O101:K99, and rectum feces were collected on 3, 12, 24, and 168 h postchallenge for the control, LF, SZ, and LFSZ groups. The rectal feces of the blank group were collected on d 14. Data were analyzed using the mixed procedure of SAS (version 9.4; SAS Institute Inc.). The E. coli K99 challenge decreased the average daily gain (ADG) and increased feed-to-gain ratio (F:G) and diarrhea frequency (control vs. blank). Compared with the control group, the LFSZ group had a higher ADG and lower F:G, and the LFSZ and SZ groups had lower diarrhea frequency compared with the control group. In addition, the LFSZ and SZ groups have no differences in diarrhea frequency compared with the blank group. Compared with the control group, the blank group had lower serum nitric oxide (NO), endothelin-1, d-lactic acid (D-LA), and lipopolysaccharide (LPS) concentrations, as well as serum IgG, IL-1ß, IL-6, IL-10, and TNF-α levels on d 7 and 14. On d 7, compared with the control group, all treatment groups had lower serum NO level, the SZ group had a lower serum D-LA concentration, and the LF and LFSZ groups had lower serum LPS concentration. On d 14, compared with the control group, the fecal microbiota of the blank group had lower Shannon, Simpson, Chao1, and ACE indexes, the LFSZ group had lower Shannon and Simpson indexes, the SZ and LFSZ groups had a higher Chao1 index, and all treatment groups had a higher ACE index. In fecal microbiota, Bifidobacterium and Actinobacteria were negatively associated with IL-10 and d-lactate, while Akkermansia was negatively associated with endothelin-1 and positively correlated with LPS, fecal scores, and d-lactate levels. Our results indicated that LF and SZ supplements could alleviate E. coli O101:K99-induced calf diarrhea individually or in combination. Supplementing 1 g/d LF and 20 g/d SZ could be a potential nutrient intervention approach to prevent bacterial diarrhea in calves.

Ruminal ergovaline and volatile fatty acid dynamics: Association with poor performance and a key growth regulator in steers grazing toxic tall fescue.

Fescue toxicosis (FT) is produced by an ergot alkaloid (i.e., ergovaline [EV])-producing fungus residing in toxic fescue plants. Associations between EV, decreased weight gain and ruminal volatile fatty acids are unclear. Feces, rumen fluid, and blood were collected from 12 steers that grazed non-toxic (NT) or toxic (E +) fescue for 28 days. The E + group exhibited decreased propionate (P), increased acetate (A), and increased ruminal A:P ratio, with similar trends in feces. Plasma GASP-1 (G-Protein-Coupled-Receptor-Associated-Sorting-Protein), a myostatin inhibitor, decreased (day 14) only in E + steers. Ergovaline was present only in E + ruminal fluid and peaked on day 14. The lower ruminal propionate and higher A:P ratio might contribute to FT while reduced GASP-1 might be a new mechanism linked to E + -related weight gain reduction. Day 14 ergovaline zenith likely reflects ruminal adaptations favoring EV breakdown and its presence only in rumen points to local, rather than systemic effects.

Effects of cashew nut shell extract supplementation on production, rumen fermentation, metabolism, and inflammatory biomarkers in transition dairy cows.

Cashew nut shell extract (CNSE) is a byproduct of the cashew nut industry, containing bioactive compounds that alter rumen fermentation patterns. Therefore, study objectives were to evaluate the effects of CNSE (59% anacardic acid and 18% cardol) on production, rumen fermentation variables, metabolism, and inflammation in transition dairy cows. A total of 51 multiparous Holstein cows were used in a randomized design and assigned to treatment based on their previous 305-d mature equivalent milk and parity. Cows were assigned to 1 of 2 treatments 21 d before expected calving: (1) CON (control diet; n = 17) or (2) CNSE-5.0 (control diet and 5.0 g/d CNSE granule [containing 50% CNSE]; n = 34). Following parturition, 17 cows (preselected at initial treatment assignment) from the CNSE-5.0 treatment were reallocated into a third treatment group: CNSE-2.5 (control diet and 2.5 g/d CNSE granule; n = 17), resulting in 3 total treatments postpartum: (1) CON, (2) CNSE-2.5, and (3) CNSE-5.0. Prepartum rumen pH was unaltered by treatment; however, postpartum rumen pH was increased (0.31 units) in CNSE cows relative to CON. Prepartum rumen ammonia N concentration tended to be decreased (34%) in CNSE-5.0 cows compared with CON, and there tended to be a quadratic effect on postpartum ammonia N, as it was decreased in CNSE-2.5 compared with CON and CNSE-5.0. Prepartum dry matter intake (DMI) was unaffected by treatment; however, postpartum DMI was increased (8%) in CNSE cows relative to CON. No treatment differences were observed in pre- or postpartum digestibility measurements. Milk and protein yields from cows fed CNSE tended to be increased (6% and 7%, respectively) relative to CON. No treatment differences were detected for energy-corrected milk, feed efficiency, body weight, body condition score, energy balance, milk composition, milk urea nitrogen, or somatic cell count. Prepartum fecal pH decreased (0.12 units) in CNSE-5.0 cows relative to CON cows but was similar between treatments postpartum. Supplementing CNSE did not affect prepartum glucose, nonesterified fatty acids (NEFA), ß-hydroxybutyrate (BHB), or insulin. However, prepartum circulating blood urea nitrogen tended to be decreased and glucagon was decreased in CNSE-5.0 cows compared with CON (9 and 20%, respectively). Additionally, CNSE supplementation decreased glucose and insulin concentrations postpartum relative to CON cows (6% and 20%, respectively). Quadratic effects were detected for postpartum circulating NEFA and BHB such that their levels were increased in CNSE-2.5 cows relative to CON and CNSE-5.0. Pre- and postpartum circulating serum amyloid A, lipopolysaccharide-binding protein, and haptoglobin were unaffected by treatment. Overall, CNSE influenced some key rumen fermentation variables, altered postabsorptive metabolism, and increased production parameters in transition dairy cows.

Forages and pastures symposium: forage biodegradation: advances in ruminal microbial ecology.

The rumen microbial ecosystem provides ruminants a selective advantage, the ability to utilize forages, allowing them to flourish worldwide in various environments. For many years, our understanding of the ruminal microbial ecosystem was limited to understanding the microbes (usually only laboratory-amenable bacteria) grown in pure culture, meaning that much of our understanding of ruminal function remained a "black box." However, the ruminal degradation of plant cell walls is performed by a consortium of bacteria, archaea, protozoa, and fungi that produces a wide variety of carbohydrate-active enzymes (CAZymes) that are responsible for the catabolism of cellulose, hemicellulose, and pectin. The past 15 years have seen the development and implementation of numerous next-generation sequencing (NGS) approaches (e.g., pyrosequencing, Illumina, and shotgun sequencing), which have contributed significantly to a greater level of insight regarding the microbial ecology of ruminants fed a variety of forages. There has also been an increase in the utilization of liquid chromatography and mass spectrometry that revolutionized transcriptomic approaches, and further improvements in the measurement of fermentation intermediates and end products have advanced with metabolomics. These advanced NGS techniques along with other analytic approaches, such as metaproteomics, have been utilized to elucidate the specific role of microbial CAZymes in forage degradation. Other methods have provided new insights into dynamic changes in the ruminal microbial population fed different diets and how these changes impact the assortment of products presented to the host animal. As more omics-based data has accumulated on forage-fed ruminants, the sequence of events that occur during fiber colonization by the microbial consortium has become more apparent, with fungal populations and fibrolytic bacterial populations working in conjunction, as well as expanding understanding of the individual microbial contributions to degradation of plant cell walls and polysaccharide components. In the future, the ability to predict microbial population and enzymatic activity and end products will be able to support the development of dynamic predictive models of rumen forage degradation and fermentation. Consequently, it is imperative to understand the rumen's microbial population better to improve fiber degradation in ruminants and, thus, stimulate more sustainable production systems.

Forage degradation in the rumen is critical to producing ruminant animals. For many years, scientists were limited to biochemical techniques to understand how ruminal microbes degraded forage, impairing our understanding of which microbes were involved with degrading which forage components. However, we have understood that as the ruminant opened up plant cells to microbial activity, a succession of microbes was involved in colonizing and breaking fiber into increasingly smaller pieces. The recent development of sequencing techniques has allowed a more detailed understanding of changes in the microbial population of the rumen during forage degradation and the types of degradative enzymes produced by this complex microbial ecosystem. We described the enzymes involved in the degradation of specific forage components, how their end products impact the microbial population through cross-feeding interactions, and how fermentation products can impact food animal production.

Effects of abomasally infused rumen fluid from corn-challenged donor cows on production, metabolism, and inflammatory biomarkers in healthy recipient cows.

Subacute rumen acidosis may cause postruminal intestinal barrier dysfunction, but this does not appear to be due to increased hindgut fermentation. Alternatively, intestinal hyperpermeability may be explained by the plethora of potentially harmful substances (e.g., ethanol, endotoxin, and amines) produced in the rumen during subacute rumen acidosis, which are difficult to isolate in traditional in vivo experiments. Therefore, objectives were to evaluate whether abomasal infusion of acidotic rumen fluid collected from donor (Donor) cows elicits systemic inflammation or alters metabolism or production in healthy recipients. Ten rumen-cannulated lactating dairy cows [249 ± 63 d in milk; 753 ± 32 kg of body weight (BW)] were randomly assigned to 1 of 2 abomasal infusion treatments: (1) healthy rumen fluid (HF; 5 L/h; n = 5) or (2) acidotic rumen fluid (AF; 5 L/h; n = 5) infused. Eight rumen-cannulated cows [4 dry, 4 lactating (lactating = 391 ± 220 d in milk); 760 ± 70 kg of BW] were used as Donor cows. All 18 cows were acclimated to a high-fiber diet (46% neutral detergent fiber; 14% starch) during an 11-d prefeeding period during which rumen fluid was collected for the eventual infusion into HF cows. During period (P) 1 (5 d), baseline data were obtained and on d 5 Donor were corn-challenged (2.75% BW ground corn after 16 h of 75% feed restriction). Cows were fasted until 36 h relative to rumen acidosis induction (RAI), and data were collected through 96 h RAI. At 12 h RAI, an additional 0.50% BW of ground corn was added, and acidotic fluid collections began (7 L/Donor every 2 h; 6 M HCl was added to collected fluid until pH was between 5.0 and 5.2). On d 1 of P2 (4 d), HF/AF cows were abomasally infused with their respective treatments for 16 h, and data were collected for 96 h relative to the first infusion. Data were analyzed in SAS (SAS Institute Inc.) using PROC MIXED. Following the corn challenge in the Donor cows, rumen pH only mildly decreased at nadir (pH = 5.64 at 8 h RAI) and remained above the desired threshold for both acute (5.2) and subacute (5.6) acidosis. In contrast, fecal and blood pH markedly decreased to acidotic levels (nadir = 4.65 and 7.28 at 36 and 30 h RAI, respectively), and fecal pH remained below 5 from 22 to 36 h RAI. In Donor cows, dry matter intake remained decreased through d 4 (36% relative to baseline) and serum amyloid A and lipopolysaccharide-binding protein markedly increased by 48 h RAI in Donor cows (30- and 3-fold, respectively). In cows that received the abomasal infusions, fecal pH decreased in AF from 6 to 12 h relative to the first infusion (7.07 vs. 6.33) compared with HF; however, milk yield, dry matter intake, energy-corrected milk, rectal temperature, serum amyloid A, and lipopolysaccharide-binding protein were unaffected. Overall, the corn challenge did not cause subacute rumen acidosis but markedly decreased fecal and blood pH and stimulated a delayed inflammatory response in the Donor cows. Abomasal infusion of rumen fluid from corn-challenged Donor cows decreased fecal pH but did not cause inflammation, nor did it create an immune-activated phenotype in recipient cows.

Non-interactive effects drive multiple stressor impacts on the taxonomic and functional diversity of atlantic stream macroinvertebrates.

Freshwaters are considered among the most endangered ecosystems globally due to multiple stressors, which coincide in time and space. These local stressors typically result from land-use intensification or hydroclimatic alterations, among others. Despite recent advances on multiple stressor effects, current knowledge is still limited to manipulative approaches minimizing biological and abiotic variability. Thus, the assessment of multiple stressor effects in real-world ecosystems is required. Using an extensive survey of 50 stream reaches across North Portugal, we evaluated taxonomic and functional macroinvertebrate responses to multiple stressors, including marked gradients of nutrient enrichment, flow reduction, riparian vegetation structure, thermal stress and dissolved oxygen depletion. We analyzed multiple stressor effects on two taxonomic (taxon richness, Shannon-diversity) and two trait-based diversity indices (functional richness, functional dispersion), as well as changes in trait composition. We found that multiple stressors had additive effects on all diversity metrics, with nutrient enrichment identified as the most important stressor in three out of four metrics, followed by dissolved oxygen depletion and thermal stress. Taxon richness, Shannon-diversity and functional richness responded similarly, whereas functional dispersion was driven by changes in flow velocity and thermal stress. Functional trait composition changed along a major stress gradient determined by nutrient enrichment and oxygen depletion, which was positively correlated with organisms possessing fast-living strategies, aerial respiration, adult phases, and gathering-collector feeding habits. Overall, our results reinforce the need to consider complementary facets of biodiversity to better identify assembly processes in response to multiple stressors. Our data suggest that stressor interactions may be less frequent in real-word streams than predicted by manipulative experiments, which can facilitate mitigation strategies. By combining an extensive field survey with an integrative consideration of multiple biodiversity facets, our study provides new insights that can help to better assess and manage rivers in a global change context.

Early Cerebrovascular Ultrasonography as a Predictor of Hemorrhagic Transformation After Thrombectomy.

OBJECTIVES: To determine the predictive value of early transcranial color-coded sonography (TCCS) for intracranial hemorrhage (ICH) in patients with large artery occlusion (LAO) stroke of carotid circulation, who were submitted to endovascular therapy (EVT) with successful reperfusion. MATERIALS AND METHODS: Retrospective study evaluating a cohort of consecutive stroke patients with LAO of the carotid circulation that were recanalyzed with EVT. We measured angle-corrected peak systolic velocities, end-diastolic velocities and mean flow velocities (PSV, EDV and MFV) of the symptomatic and asymptomatic middle cerebral artery (MCA). The ratio between MFV of the symptomatic MCA and MFV of the asymptomatic MCA (MCA-Ra) was calculated. Parenchymal hematoma in the 24 hours control CT was considered as ICH. Univariate associations and multivariate analyses were used to identify early independent predictors for ICH among TCCS findings. RESULTS: We included 234 patients, mean age 72.5 (SD 12.6) years, 52.1% male. The mean time between recanalization and TCCS was 12.3 hours (range 3-22). Patients who developed postinterventional ICH showed a higher MCA-Ra (1.02 ± 0.26 vs 1.16 ± 0,21, p = 0.036). In multivariate analysis, only higher MCA-Ra remained independently associated with postinterventional ICH (OR: 6.778, 95%CI: 1.152-39.892, p = 0.034). A value of MCA-Ra ≥ 1,05 was associated with ICH, showing a sensitivity of 81.3% and a specificity of 65.9%; the AUC based of the ROC analysis was 0.688 (95% CI 0.570-0.806). CONCLUSION: TCCS performed within the first 24 hours after stroke onset can help to predict hemorrhagic transformation in patients with LAO.

Inter-species bystander effect: Eisenia fetida and Enchytraeus albidus exposed to uranium and cadmium.

The bystander effect is commonly defined as the observation of effects in nonirradiated cells and tissues when the later are in contact with irradiated cells/ tissues. More recently the occurrence of bystander effect between organisms of the same species has been also demonstrated. Nevertheless, there is limited knowledge about this effect between soil dwelling organisms from different taxonomic groups, as well as in response to stressors other than ionizing radiation. Moreover, data reporting this phenomenon for soil invertebrates are scarce. The results herein presented contribute for the understanding of the impacts of cadmium and uranium in the DNA integrity of two terrestrial oligochaetes species (Eisenia fetida and Enchytraeus albidus). The evaluation was based on the quantification of the effects in the DNA integrity of the coelomocytes using the alkaline comet assay technique. This work reports the existence of bystander signaling from terrestrial earthworms to enchytraeids and from enchytraeids to earthworms when the organisms were exposed to Cd. These results reinforce that the bystander effect seems to be related with the genotoxic activity of stressors, and not exclusive of radiotoxic contaminants. Further, the bystander effect occurs between different species and under real environmental conditions, even in complex matrices, as the soil.

Metals and low dose IR: Molecular effects of combined exposures using HepG2 cells as a biological model.

Uranium mining sites produce residues rich in metals and radionuclides, that may contaminate all environmental matrices, exposing human and non-human biota to low doses of ionizing radiation (LDIR) and to the chemical toxicity of several metals. To date, experimental and radio-epidemiological studies do not provide conclusive evidence of LDIR induced cancer. However, co-exposures (LDIR plus other contaminants), may increase the risks. To determine the potential for genotoxic effects in human cells induced by the exposure to LDIR plus metals, HEPG2 cells were exposed to different concentrations of a uranium mine effluent for 96 h. DNA damage was evaluated using the comet assay and changes in the expression of tumor suppressor and oncogenes were determined using qPCR. Results show that effluent concentrations higher than 5%, induce significant DNA damage. Also, a significant under-expression of ATM and TP53 genes and a significant overexpression of GADD45a gene was observed. Results show that the exposure to complex mixtures cannot be disregarded, as effects were detected at very low doses. This study highlights the need for further studies to clarify the risks of exposure to LDIR along with other stressors, to fully review the IR exposure risk limits established for human and non-human biota.

Determinants of high residual post-PCV13 pneumococcal vaccine-type carriage in Blantyre, Malawi: a modelling study.

BACKGROUND: In November 2011, Malawi introduced the 13-valent pneumococcal conjugate vaccine (PCV13) into the routine infant schedule. Four to 7 years after introduction (2015-2018), rolling prospective nasopharyngeal carriage surveys were performed in the city of Blantyre. Carriage of Streptococcus pneumoniae vaccine serotypes (VT) remained higher than reported in high-income countries, and impact was asymmetric across age groups. METHODS: A dynamic transmission model was fit to survey data using a Bayesian Markov-chain Monte Carlo approach, to obtain insights into the determinants of post-PCV13 age-specific VT carriage. RESULTS: Accumulation of naturally acquired immunity with age and age-specific transmission potential were both key to reproducing the observed data. VT carriage reduction peaked sequentially over time, earlier in younger and later in older age groups. Estimated vaccine efficacy (protection against carriage) was 66.87% (95% CI 50.49-82.26%), similar to previous estimates. Ten-year projected vaccine impact (VT carriage reduction) among 0-9 years old was lower than observed in other settings, at 76.23% (CI 95% 68.02-81.96%), with sensitivity analyses demonstrating this to be mainly driven by a high local force of infection. CONCLUSIONS: There are both vaccine-related and host-related determinants of post-PCV13 pneumococcal VT transmission in Blantyre with vaccine impact determined by an age-specific, local force of infection. These findings are likely to be generalisable to other Sub-Saharan African countries in which PCV impact on carriage (and therefore herd protection) has been lower than desired, and have implications for the interpretation of post-PCV carriage studies and future vaccination programs.

Immigrants' access to health care: Problems identified in a high-risk tuberculosis population.

INTRODUCTION: Immigrants may utilize health care services differently than other residents and may also have a greater risk for tuberculosis (TB). OBJECTIVE: Identify barriers to healthcare access by immigrants, factors associated with these barriers, and discuss strategies that may reduce these barriers. MATERIAL AND METHODS: Anonymous questionnaires were given to immigrants at National Immigrant Support Centres between 2015 and 2016. Barriers to healthcare were identified using logistic regression. RESULTS: One-hundred and nineteen questionnaires were administered to immigrants, 9 of whom (8%) presented with TB while in Portugal. Twenty-one percent of immigrants reported barriers to healthcare access, and 69% had general practitioners (GPs). The presence of barriers to healthcare access was negatively associated with having a GP and with being married or in a de facto union. CONCLUSIONS: A considerable proportion of immigrants reported having difficulties accessing healthcare services in Portugal where legally these barriers are nonexistent. Certain factors were associated with these difficulties.

Genomic and epidemiological monitoring of yellow fever virus transmission potential.

The yellow fever virus (YFV) epidemic in Brazil is the largest in decades. The recent discovery of YFV in Brazilian Aedes species mosquitos highlights a need to monitor the risk of reestablishment of urban YFV transmission in the Americas. We use a suite of epidemiological, spatial, and genomic approaches to characterize YFV transmission. We show that the age and sex distribution of human cases is characteristic of sylvatic transmission. Analysis of YFV cases combined with genomes generated locally reveals an early phase of sylvatic YFV transmission and spatial expansion toward previously YFV-free areas, followed by a rise in viral spillover to humans in late 2016. Our results establish a framework for monitoring YFV transmission in real time that will contribute to a global strategy to eliminate future YFV epidemics.

Effects of injectable trace minerals administered concurrently with a modified live virus vaccine on long-term protection against bovine viral diarrhea virus acute infection in dairy calves.

The objective was to evaluate the effects of injectable trace minerals (ITM) concurrent with modified-live virus (MLV) vaccination on protection from bovine viral diarrhea virus (BVDV) infection in dairy calves. In a previous study (Palomares et al., 2016), thirty dairy calves received two doses of a MLV vaccine subcutaneously (SC), concurrently with ITM (n = 15) or saline (n = 15), SC. Five months later, 20 of these calves received ITM (G1, n = 10) or saline (G2, n = 10) according to their previous groups and were challenged intranasally with BVDV2. Five unvaccinated calves were also challenged with BVDV2 (G3). Blood samples were collected on days 0 (BVDV challenge), 3, 5, 6, 7, 8, 9, 11, 14, 18, 21, 32 and 61 for leukocyte count, virus isolation and BVDV serum neutralizing antibodies (SNA). Mild-moderate clinical signs were observed in G3 after BVDV challenge. Group 1 showed lower sum health score and nasal score on d5 and fecal score on d8 compared to G2. Rectal temperature and leukocyte counts were not different between G1 and G2. In contrast, G3 calves had significant leukopenia and lymphopenia from d3 to d7 (P < .05) and higher rectal temperatures on d6 to d8, compared to values on d0 (P < .05). All unvaccinated calves became viremic, while viremia was not detected in G1 or G2. Average daily gain was not different between vaccinated groups, however, only G1 calves had significantly greater (P = .04) ADG compared to non-vaccinated calves during the first 14 days post challenge. Vaccinated calves treated or not with ITM were protected from BVDV2 infection five months post-vaccination.

RIBE at an inter-organismic level: A study on genotoxic effects in Daphnia magna exposed to waterborne uranium and a uranium mine effluent.

The induction of RIBE (Radiation Induced Bystander Effect) is a non-target effect of low radiation doses that has already been verified at an inter-organismic level in fish and small mammals. Although the theoretical impact in the field of environmental risk assessment (ERA) is possible, there is a gap of knowledge regarding this phenomenon in invertebrate groups and following environmentally relevant exposures. To understand if RIBE should be considered for ERA of radionuclide-rich wastewaters, we exposed Daphnia magna (<24 h and 5d old) to a 2% diluted uranium mine effluent for 48 h, and to a matching dose of waterborne uranium (55.3 µg L-1). Then the exposed organisms were placed (24 and 48 h) in a clean medium together with non-exposed neonates. The DNA damage observed for the non-exposed organisms was statistically significant after the 24 h cohabitation for both uranium (neonates p = 0.002; 5 d-old daphnids p = <0.001) and uranium mine effluent exposure (only for neonates p = 0.042). After 48 h cohabitation significant results were obtained only for uranium exposure (neonates p = 0.017; 5 d-old daphnids p = 0.013). Although there may be some variability associated to age and exposure duration, the significant DNA damage detected in non-exposed organisms clearly reveals the occurrence of RIBE in D. magna. The data obtained and here presented are a valuable contribution for the discussion about the relevance of RIBE for environmental risk assessment.

Uranium mining wastes: The use of the Fish Embryo Acute Toxicity Test (FET) test to evaluate toxicity and risk of environmental discharge.

Active and abandoned uranium mining sites often create environmentally problematic situations, since they cause the contamination of all environmental matrices (air, soil and water) with stable metals and radionuclides. Due to their cytotoxic, genotoxic and teratogenic properties, the exposure to these contaminants may cause several harmful effects in living organisms. The Fish Embryo Acute Toxicity Test (FET) test was employed to evaluate the genotoxic and teratogenic potential of mine liquid effluents and sludge elutriates from a deactivated uranium mine. The aims were: a) to determine the risk of discharge of such wastes in the environment; b) the effectiveness of the chemical treatment applied to the uranium mine water, which is a standard procedure generally applied to liquid effluents from uranium mines and mills, to reduce its toxicological potential; c) the suitability of the FET test for the evaluation the toxicity of such wastes and the added value of including the evaluation of genotoxicity. Results showed that through the FET test it was possible to determine that both elutriates and effluents are genotoxic and also that the mine effluent is teratogenic at low concentrations. Additionally, liquid effluents and sludge elutriates affect other parameters namely, growth and hatching and that water pH alone played an important role in the hatching process. The inclusion of genotoxicity evaluation in the FET test was crucial to prevent the underestimation of the risks posed by some of the tested effluents/elutriates. Finally, it was possible to conclude that care should be taken when using benchmark values calculated for specific stressors to evaluate the risk posed by uranium mining wastes to freshwater ecosystems, due to their chemical complexity.

Utilization of canola and sunflower meals as replacements for soybean meal in a corn silage-based stocker system.

Two experiments were conducted to evaluate 3 silage-based stocker diets. In Exp. 1, diets were fed to a total of 276 animals over a period of 3 yr and performance data was collected. In Exp. 2, the same diets were subjected to in vitro digestion for 5 time periods: 0, 6, 12, 24, and 48 h, to evaluate IVDMD, production of fermentation end products, and efficiency of transformation of energy. The experimental diets were similar, except for their protein supplements. They were composed of: 1) 74% corn silage, 15.2% ground ear corn, and 10.8% soybean meal (SBM); 2) 74.4% corn silage, 9.8% ground ear corn, and 15.8% canola meal (CAN); 3) 74.5% corn silage, 9.8% ground ear corn, and 15.7% sunflower meal (SUN). Results from Exp. 1 showed that DMI was similar across all treatments (P = 0.167), but ADG was greater (P = 0.007) for animals fed either SBM or CAN than for animals fed SUN (1.29, 1.28, and 1.20 kg/d, respectively). Both CAN and SUN significantly reduced (P < 0.001) daily feeding cost per animal in comparison to SBM. Exp. 2 revealed that total VFA production was similar for all treatments (P = 0.185), and greatest molar proportions of propionate were observed for SBM and CAN (P = 0.02). Additionally, IVDMD was highest for SBM (P < 0.001). Regression analysis showed that most of the evaluated traits followed a quadratic trend for incubation times (P ≤ 0.02). On average, the in vitro technique used in this study was able to account for 97.03% of the caloric transformations suffered by DE throughout the different incubation times. Overall, our findings revealed that although animals receiving SUN had the cheapest daily feeding cost, important traits like ADG and feed conversion rate were negatively affected by this treatment. In contrast, data showed that CAN was an effective replacement for SBM for it maintained similar animal performance while decreasing feed costs. Therefore, from a producer standpoint, CAN is a viable alternative to replace the more costly SBM diet in silage-based stocker operations.