To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Maternal milk consumption can cause changes in the mammary epithelium of the offspring that result in the expression of molecules involved in the induction of differentiation, reducing the risk of developing mammary cancer later in life. We previously showed that animals that maintained a higher intake of maternal milk had a lower incidence of mammary cancer. In the present study, we evaluated one of the possible mechanisms by which the consumption of maternal milk could modify the susceptibility to mammary carcinogenesis. We used Sprague Dawley rats reared in litters of 3 (L3), 8 (L8), or 12 (L12) pups per mother in order to generate a differential consumption of milk. Whole mounts of mammary glands were performed to analyze the changes in morphology. Using real-time polymerase chain reaction (PCR), we analyzed the expression of mammary Pinc, Tbx3, Stat6, and Gata3 genes. We use the real-time methylation-specific polymerase chain reaction method to assess the methylation status of Stat6 and Gata3 CpG sites. Our findings show an increase in the size of the epithelial tree and a smaller number of ducts called terminal end buds in L3 vs. L12. We observed an increased expression of mRNA of Stat6, Gata3, Tbx3, and a lower expression of Pinc in L3 with respect to L12. Stat6 and Gata3 are more methylated in the CpG islands of the promoter analyzed in L12 vs. L3. In conclusion, the increased consumption of maternal milk during the postnatal stage generates epigenetic and morphological changes associated with the differentiation of the mammary gland.
A novel underwater vehicle configuration with an operating principle as the Sepiida animal is presented and developed in this paper. The mathematical equations describing the movements of the vehicle are obtained using the Newton–Euler approach. An analysis of the dynamic model is done for control purposes. A prototype and its embedded system are developed for validating analytically and experimentally the proposed mathematical representation. A real-time characterization of one mass is done to relate the pitch angle with the radio of displacement of the mass. In addition, first validation of the closed-loop system is done using a linear controller.
Accurate estimates of methane (CH4) production by cattle in different contexts are essential to developing mitigation strategies in different regions. We aimed to: (i) compile a database of CH4 emissions from Brazilian cattle studies, (ii) evaluate prediction precision and accuracy of extant proposed equations for cattle and (iii) develop specialized equations for predicting CH4 emissions from cattle in tropical conditions. Data of nutrient intake, diet composition and CH4 emissions were compiled from in vivo studies using open-circuit respiratory chambers, SF6 technique or the GreenFeed® system. A final dataset containing intake, diet composition, digestibility and CH4 emissions (677 individual animal observations, 40 treatment means) obtained from 38 studies conducted in Brazil was used. The dataset was divided into three groups: all animals (GEN), lactating dairy cows (LAC) and growing cattle and non-lactating dairy cows (GCNL). A total of 54 prediction equations available in the literature were evaluated. A total of 96 multiple linear models were developed for predicting CH4 production (MJ/day). The predictor variables were DM intake (DMI), gross energy (GE) intake, BW, DMI as proportion of BW, NDF concentration, ether extract (EE) concentration, dietary proportion of concentrate and GE digestibility. Model selection criteria were significance (P < 0.05) and variance inflation factor lower than three for all predictors. Each model performance was evaluated by leave-one-out cross-validation. The Intergovernmental Panel on Climate Change (2006) Tier 2 method performed better for GEN and GCNL than LAC and overpredicted CH4 production for all datasets. Increasing complexity of the newly developed models resulted in greater performance. The GCNL had a greater number of equations with expanded possibilities to correct for diet characteristics such as EE and NDF concentrations and dietary proportion of concentrate. For the LAC dataset, equations based on intake and animal characteristics were developed. The equations developed in the present study can be useful for accurate and precise estimation of CH4 emissions from cattle in tropical conditions. These equations could improve accuracy of greenhouse gas inventories for tropical countries. The results provide a better understanding of the dietary and animal characteristics that influence the production of enteric CH4 in tropical production systems.
This work presents updates in the diagnostics systems, magnetohydrodynamics (MHD) calculations and simulations of microwave heating scenarios of the small modular Stellarator of Costa Rica 1 (SCR-1). Similarly, the design of a flexible bolometer and magnetic diagnostics (a set of Mirnov coils, Rogowski coils and two diamagnetic loops) are introduced. Furthermore, new MHD equilibrium calculations for the plasma of the SCR-1 device were performed using the VMEC code including the poloidal cross-section of the magnetic flux surfaces at different toroidal positions, profiles of the rotational transform, magnetic well, magnetic shear and total magnetic field norm. Charged particle orbits in vacuum magnetic field were computed by the magnetic field solver BS-SOLCTRA (Vargas et al. In 27th IAEA Fusion Energy Conference (FEC 2018), 2018. IAEA). A visualization framework was implemented using Paraview (Solano-Piedra et al. In 23rd IAEA Technical Meeting on the Research Using Small Fusion Devices (23rd TM RUSFD), 2017) and compared with magnetic mapping results (Coto-Vílchez et al. In 16th Latin American Workshop on Plasma Physics (LAWPP), 2017, pp. 43–46). Additionally, simulations of microwave heating scenarios were performed by the IPF-FDMC full-wave code. These simulations calculate the conversion of the ordinary waves to extraordinary waves and allow us to identify the location where the conversion takes place. Finally, the microwave heating scenarios for the
toroidal position are presented. The microwave heating scenarios showed that the O–X–B mode conversion is around 12–14 %. It was possible to identify the spatial zone where the conversion takes place (upper hybrid frequency).
Although the tambaqui (Colossoma macropomum) is the most cultivated native fish species in Brazil, estimated breeding values for growth traits are rarely used for selection of superior individuals in commercial fingerling production. This study aimed to estimate the (co)variance components of growth traits. Body weight, length and width of 2500 tambaqui were determined at tagging and at 6 and 12 months after tagging in a commercial breeding programme in Brazil. Heritability estimates were low for traits measured at tagging (0.10 to 0.19) and moderate to high for traits measured at 6 and 12 months (0.23 to 0.81). Common full-sib effects were high at tagging (>73%), low at 6 months and negligible at 12 months. Positive genetic correlations were found among growth traits at 12 months (0.84 to 0.99) and between growth traits at 6 and 12 months (0.80 to 0.92). These results show that animal selection can be performed at 6 months after tagging. Expected genetic gains for growth traits ranged from 8% to 31%. A simulation of the sex ratio was performed, as individuals did not reach sexual maturity during the experimental period. Because of the sexual dimorphism, more accurate heritability estimates were obtained when considering the female proportion to be 90% in the high-weight group. The findings indicate that it is possible to obtain considerable genetic gains in growth by selecting for growth traits. The development of a tool to determine the sex of animals at early stages can improve the response to selection in tambaqui.
There is a long history of exploitation of the South American river turtle Podocnemis expansa. Conservation efforts for this species started in the 1960s but best practices were not established, and population trends and the number of nesting females protected remained unknown. In 2014 we formed a working group to discuss conservation strategies and to compile population data across the species’ range. We analysed the spatial pattern of its abundance in relation to human and natural factors using multiple regression analyses. We found that > 85 conservation programmes are protecting 147,000 nesting females, primarily in Brazil. The top six sites harbour > 100,000 females and should be prioritized for conservation action. Abundance declines with latitude and we found no evidence of human pressure on current turtle abundance patterns. It is presently not possible to estimate the global population trend because the species is not monitored continuously across the Amazon basin. The number of females is increasing at some localities and decreasing at others. However, the current size of the protected population is well below the historical population size estimated from past levels of human consumption, which demonstrates the need for concerted global conservation action. The data and management recommendations compiled here provide the basis for a regional monitoring programme among South American countries.
Advanced courses in Applied Crystallography for Nanosciences are not often delivered in Academia and, consequently, require the organization of events specifically tailored to PhD students, postdocs, and young researchers at the very beginning of their scientific careers.
The objective of this study was to determine the serotype distribution and antibiotic resistance of invasive pneumococcal disease (IPD) strains in children from Lima, Peru, before and after the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7), which was introduced in the national immunisation program on 2009. We conducted a prospective, multicentre, passive surveillance IPD study during 2006–2008 and 2009–2011, before and right after the introduction of PCV7 in Peru. The study was performed in 11 hospitals and five private laboratories in Lima, Peru, in patients <18 years old, with sterile site cultures yielding Streptococcus pneumoniae. In total 159 S. pneumoniae isolates were recovered. There was a decrease in the incidence of IPD in children <2 years old after the introduction of PCV7 (18.4/100 000 vs. 5.1/100 000, P = 0.004). Meningitis cases decreased significantly in the second period (P = 0.036) as well as the overall case fatality rate (P = 0.025), including a decreased case fatality rate of pneumonia (16.3% to 0%, P = 0.04). PCV7 serotypes showed a downward trend. Vaccine-preventable serotypes caused 78.9% of IPD cases, mainly 14, 6B, 5, 19F and 23F. A non-significant increase in erythromycin resistance was reported. Our findings suggest that the introduction of PCV7 led to a significant decrease of IPD in children under 2 years old and in the overall case fatality rate.
Environmental factors during perinatal life can lead to changes in the mammary gland, making it susceptible to cancer in adulthood. Breastfeeding has a special importance since it takes place at a critical period of growth and development of the newborn. We aimed to analyze if an appropriate lactation protects the offspring against mammary carcinogenesis during adult life and explore the mechanisms involved in the protective effect. One-day-old Sprague-Dawley female rats were randomly distributed in litters of three (L3), eight (L8) or 12 (L12) pups per dam, to induce a differential consumption of breast milk. At 55 days of age, the animals were treated with a single dose of dimethylbenzanthracene to study tumor latency, incidence and progression. Histological, immunohistochemical and Western blot studies were performed. We observed lower incidence and higher latency in L3 compared to the other groups. The mitotic index and expression of proliferating cell nuclear antigen (PCNA) was significantly augmented in tumors of L12 rats compared to L3 and L8, while the apoptotic index was augmented in tumors of L3 v. L12. Cleaved caspase 8 was significantly higher in tumors from L3 compared to L12. Tumors developed in L3 have a greater number of apoptotic bodies and a greater expression of caspase 8. These results demonstrate that the animals that maintained a higher intake of maternal milk (L3) presented lower incidence and greater tumor latency. Lower consumption of breast milk (L12) would increase tumor mitosis and the expression of PCNA, explaining the higher tumor incidence observed in this group.
The degradation of organic molecules in an aqueous medium using heterogeneous photocatalysis depends on the chemical composition and concentration of the organic compound, the crystalline and morphological nature of the photocatalyst, the pH of the dye dilution, and the reaction temperature. Since photocatalytic degradation is a process that occurs on the surface of the catalytic material, it is desirable to induce maximum adsorption of the organic compound. One strategy to achieve this is to functionalize the surface of the catalyst to retain the molecule of interest. In this work, we studied the interaction of acid orange 7 (AO7) with commercial TiO2-anatase powder catalyst, and with a catalyst synthesized in house using titanium tetrachloride and ethanolamine (TiO2-et). Our results indicate that there is no adsorption of the AO7 dye on the TiO2-et particles. The infrared spectrum of the TiO2-et particles is presented.
Non-decorticated sunflower meal (SFM) is a potential protein source for dairy cows with high-fibre content but high ruminal degradability. The effect of replacement of soybean meal (SBM) and wheat middlings (WM) with SFM on the intake, digestibility, microbial protein synthesis, nitrogen utilization and milk production of dairy cows was evaluated. Twelve Holstein cows were blocked by days in milk and distributed in three 4 × 4 Latin squares. Diets were formulated to be isonitrogenous and contained 550 g maize silage/kg dry matter (DM). Treatment diets were no SFM (CON) or 70, 140 and 210 g/kg DM of SFM replacing fixed mixture of SBM and WM (536 and 464 g/kg of the mixture, respectively). The inclusion of SFM in diet did not affect DM intake, but intake of rumen degradable protein increased linearly. Inclusion of SFM reduced or tended to reduce total-tract digestibility of non-fibre carbohydrate, total digestible nutrients and excretion of purine derivatives. Milk production, milk protein content and efficiency of nitrogen use for lactation were reduced with increasing levels of SFM in the diet. The use of non-decorticated SFM as a replacement for SBM–WM mixture in diet reduces performance and efficiency of nutrient use in lactating dairy cows. The outcome of the current study is attributed to reduced fibre digestibility in SFM hulls. Therefore, future studies should evaluate the use of decorticated SFM.
An experiment was conducted to evaluate whether dietary reduction and sex class affect nutrient intake, digestibility, purine derivative (PD) excretion and heat tolerance coefficient in lambs. Thirty-five hair lambs (14.5 ± 0.89 kg initial body weight (BW), 2 months old) were used in a completely randomized study with a 3 × 3 factorial arrangement, three sex classes (11 intact males, 12 castrated males and 12 females) and three levels of feeding (ad libitum, 300 and 600 g/kg/dry matter (DM) feed restriction) for 120 days. Intact and castrated males showed higher intakes of DM and neutral detergent fibre corrected for ash and protein (NDFap) than females. At 300 g/kg/DM feed restriction, NDFap digestibility was lower in intact males than in other classes; however, no differences were found between classes when subjected to ad libitum feeding or 600 g/kg/DM. The basal endogenous nitrogen and endogenous urinary losses were highest in intact males. Allantoin, uric acid and PD excretion, as well as PD absorption and microbial protein production were lowest in the animals subjected to 600 g/kg/DM feed restriction. Microbial protein synthesis (MPS) was highest in animals subjected to 600 g/kg/DM feed restriction. The lowest temperatures were observed in animals subjected to 600 g/kg/DM feed restriction. The heat tolerance coefficient was highest in animals subjected to 600 g/kg/DM feed restriction. In conclusion, feed restriction reduced the time spent on feeding and rumination but increased the digestibility of DM. The restriction level of 600 g/kg/DM maximized MPS and infrared thermography indicated an elevated heat tolerance coefficient.
Objective: Perceived upright depends on three main factors: vision, graviception, and the internal representation of the long axis of the body. We assessed the relative contributions of these factors in individuals with sub-acute and chronic stroke and controls using a novel tool; the Oriented Character Recognition Test (OCHART). We also considered whether individuals who displayed active pushing or had a history of pushing behaviours had different weightings than those with no signs of pushing. Method: Three participants experienced a stroke <3 months before the experiment: one with active pushing. In total, 14 participants experienced a stroke >6 months prior: eight with a history of pushing. In total, 12 participants served as healthy aged-matched controls. Visual and graviceptive cues were dissociated by orienting the visual background left, right, or upright relative to the body, or by orienting the body left, right, or upright relative to gravity. A three-vector model was used to quantify the weightings of vision, graviception, and the body to the perceptual upright. Results: The control group showed weightings of 13% vision, 25% graviception, and 62% body. Some individuals with stroke showed a similar pattern; others, particularly those with recent stroke, showed different patterns, for example, being unaffected by one of the three factors. The participant with active pushing behaviour displayed an ipsilesional perceptual bias (>30°) and was not affected by visual cues to upright. Conclusion: The results of OCHART may be used to quantify the weightings of multisensory inputs in individuals post-stroke and may help characterize perceptual sources of pushing behaviours.
Minerals are limiting factors in animal production, and the knowledge of mineral requirements for livestock is crucial to the success of a commercial enterprise. Hair sheep may have different mineral requirements than those presents by the international committees. A study was carried to evaluate the net calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na), potassium (K), zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu) requirements for the growth and maintenance of Brazilian Somali lambs. A total of 48 hair lambs (13.5±1.8 kg) aged 60±15 days were allocated to individual pens. Eight animals were slaughtered at the beginning of the experiment to serve as a reference group to estimate initial empty BW (EBW) and initial body composition. The remaining lambs (n=40) were assigned to a completely randomized design with eight replications in five levels of metabolizable energy (ME; 4.93, 8.65, 9.41, 10.12 and 11.24 MJ/kg DM). When the lambs of a given treatment reached an average BW of 28 kg, they were slaughtered. Initial body composition was used to calculate the retention of minerals. Mineral body composition was fit using a logarithmic equation in the form of a nonlinear model. The maintenance requirements were estimated from regressions of mineral retention in the empty body on mineral intake. The body mineral concentration decreased in lambs with a BW ranging from 15 to 30 kg. The net mineral requirements (100 g/day of average daily gain (ADG)) decreased from 0.52 to 0.51 g for Ca, 0.28 to 0.23 g for P, 0.02 to 0.02 g for Mg, 0.09 to 0.08 g for Na, 0.11 to 0.09 g for K, 1.30 to 1.08 mg for Zn, 3.77 to 3.22 mg for Fe, 0.08 to 0.06 mg for Mn and 0.09 to 0.08 mg for Cu when BW increased from 15 to 30 kg. The daily net requirements for maintenance per kilogram of BW were 30.13 mg of Ca, 27.58 mg of P, 1.26 mg of Mg, 4.12 mg of Na, 8.11 mg of K, 0.133 mg of Zn, 0.271 mg of Fe, 0.002 mg of Mn and 0.014 mg of Cu. The results of this study indicate that the net mineral requirements for weight gain and maintenance in Brazilian Somali lambs are different than the values that are commonly recommended by the main evaluation systems for feed and nutritional requirements for sheep. These results for the nutritional requirements of minerals may help to optimize mineral supply for hair sheep.
Here we evaluated the effect of fermented milk supplemented with whey protein (approximately 80 % protein), probiotic (Bifidobacterium animalis subsp. lactis BB12) and pomegranate juice (Punica granatum L.) on the physical performance, intestinal motility and villi structure, inflammatory markers and intestinal microbiota of rats under high-intensity acute exercise. In all, twenty-four Wistar rats were separated into groups: control (Ctrl), supplemented (Supp), exercised (Exe) and exercised and supplemented (Exe+Supp). Rats in the Supp groups received fermented milk during 6 weeks by oral administration. At the end of the supplementation period, the Exe groups were submitted to high-intensity acute exercise on a treadmill. We found that intense acute exercise caused changes in the intestinal villi interspace, changes in the proportion of Lactobacillus species and an increase in Clostridium species, as well as a decrease in intestinal motility. Supplementation increased intestinal motility, and maintained the intestinal villi interspace and the natural microbiota proportions of the exercised rats. Physical performance was not improved by fermented milk supplementation. We conclude that the fermented milk containing whey protein, B. animalis (BB12) and pomegranate juice can re-establish intestinal microbiota and protect the animals from the undesirable effects of intense acute exercise.
Natural control by predators and parasitoids provides an important and often unnoticed ecosystem service to agricultural landscapes by reducing pest populations in crops. The current model of horticultural intensification in south-eastern Spain produces high yields but has also resulted in a landscape almost completely covered by plastic. Promoting natural areas among greenhouses could enhance biodiversity, by being beneficial insects, and reduce pest pressure outdoors. The first step is to ascertain how pests and their natural enemies (NEs) use Mediterranean vegetation for selecting the best plants for pest suppression outdoors. The abundance of the two major horticultural pests, the tobacco whitefly, Bemisia tabaci, and the western flower thrips, Frankliniella occidentalis, together with their NEs, were assayed in 22 flowering perennial plants, which were newly planted in an experimental field surrounded by greenhouses. Eight plant species were identified as the most critical species for sustaining pest populations outdoors. A set of five plant species supported a medium level of pests, and another set of ten plant species supported the lowest level of both pests. Tobacco whitefly occurred in a few plants species, whereas western flower thrips occurred on almost all the plant species studied, and was favoured by the presence of flowers in perennial plants. The results suggest that plant diversity may provide relatively few acceptable host plants for tobacco whitefly than for western flower thrips. NEs were generally collected in plants that also supported abundance of pests, indicating that host/prey availability, more than food resources from flowers, was a stronger predictor of NE abundance in perennial plants. Field trials using the plants with the lowest host acceptance by pests are needed in order to ascertain whether pest abundance outdoors is reduced.
An experiment was carried to evaluate the energy and protein requirements for the growth and maintenance of lambs of different sex classes. In all, 38 hair lambs (13.0±1.49 kg initial BW and 2 months old) were allocated in a factorial design with diet restriction levels (ad libitum, 30% and 60% feed restriction) and sex classes (castrated and non-castrated males). Four animals from each sex class were slaughtered at the beginning of the trial as a reference group to estimate the initial empty BW and body composition. The remaining lambs were weighed weekly to calculate BW gain (BWG), and when the animals fed ad libitum reached an average BW of 30 kg, all of the experimental animals were slaughtered. Before slaughter, fasted BW (FBW) was determined after 18 h without feed and water. Feed restriction induced reductions in body fat and energy concentration, whereas water restriction showed the opposite effect, and the protein concentration was not affected. The increase in BW promoted increases in body fat and energy content, and these increases were greater in castrated lambs, whereas the protein content was similar between classes tending to stabilize. The net energy required for gain (NEg) and the net protein required for gain (NPg) were not affected by sex class; therefore, an equation was generated for the combined results of both castrated and non-castrated lambs. The NEg varied from 1.13 to 2.01 MJ/day for lambs with BW of 15 and 30 kg and BWG of 200 g. The NPg varied from 24.57 to 16.33 g/day for lambs with BW of 15 and 30 kg and BWG of 200 g. The metabolizable energy efficiency for gain (kg) was 0.37, and the metabolizable protein efficiency for gain (kpg) was 0.28. The net energy required for maintenance (NEm) and the net requirement of protein for maintenance (NPm) did not differ between castrated and non-castrated lambs, with values of 0.241 MJ/kg FBW0.75 per day and 1.30 g/kg FBW0.75 per day, respectively. The metabolizable energy efficiency for maintenance (km) was 0.60, and the efficiency of metabolizable protein use for maintenance (kpm) was 0.57. Nutritional requirements for growth and maintenance did not differ between castrated and non-castrated lambs. This study emphasizes the importance of updating the tables of international committees and of including data obtained from studies with sheep breeds raised in tropical conditions, with the purpose of improving the productive efficiency of the animals