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 email@example.com
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.
This work attempts to confirm the effect of an enriched diet with n-3 polyunsaturated fatty acids (PUFA) trying to mitigate the reproductive performances issues such as low conception rate of primiparous rabbits. A total of 127 does were fed ad libitum throughout their two first cycles with two diets with different fat sources: mixed fat in the control and salmon oil in the enriched one, with 3.19 g/100 g (n=63 does) and 28.77 g/100 g (n=64 does) of n-3 of the total fatty acid, respectively. Feed intake was similar between groups (P>0.05). Plasma progesterone concentration was higher in the enriched females than in control ones at 7 (30.9±2.18 v. 23.9±2.30 ng/ml, respectively; P=0.029) and 14 (38.7±2.18 v. 28.2±2.30 ng/ml, respectively; P=0.001) days of first gestation. Considering both cycles, reproductive parameters of mothers (fertility, duration of gestation and prolificacy) and litter parameters (weight at parturition and weaning, mortality and average daily gain (ADG) of kits during lactation) were similar in both groups. However, individual measurements of neonates of enriched group improved 5.87%, 7.10% and 18.01% (P<0.05) in terms of crown-rump length, biparietal and thoracic diameters, respectively, compared to control ones at first parturition. It is noteworthy that at the second insemination, critical point in rabbit, fertility rate of enriched group did not decline as sharply as in the control group (89.7% v. 76.6%, respectively; P=0.067), although ADG and littler weight were slightly lower at the second lactation after PUFA enrichment (P<0.05). Total PUFA and unsaturated index of milk of enriched does group were significantly elevated than in control one (33.3±0.02 v. 23.2±0.02 g/100 g and 1.20±0.00 v. 0.86±0.00, respectively; P<0.05). Finally, plasma progesterone, ovulation rate, fertility and embryo development at 3.5 days after the artificial insemination were similar between diets (P>0.05), but embryo apoptosis rate was higher in control group than in enriched one (31.1±4.56% v. 17.1±3.87%, respectively; P<0.05). In conclusion, dietary PUFA enrichment from the rearing and throughout two productive cycles improved plasma progesterone during pregnancy, fertility, milk fatty acid profile and neonates development of primiparous supporting the beneficial effect of n-3 PUFA supplementation in rabbit does.
GM24 is a small visible nebulosity in the vicinity of a molecular cloud. In this contribution we present the results of continuum (6-cm) and CO line (J = 1 → 0) radio observations, infrared maps, broad-band photometry and low-resolution spectroscopy as well as long-slit Echelle Ha spectroscopy. We found evidence that the GM24 = PP85 nebula is part of a larger region where star formation occurred in the past 104 years; the region is embedded in a typical molecular cloud with a dimension of ∼ 10 pc and mass of ∼104 M⊙. A compact radio H II region seems to be associated with GM24 and with one of the mid-infrared peaks detected. The nebula is most probably the visible part of an embedded H II region that is starting to emerge from the cloud. The other infrared peaks found in its vicinity (∼ 1 pc) are probably associated with less evolved stellar objects. The complex also shows an extended near-infrared flux which we believe to arise in a reflection nebula. From energy arguments, we found that the luminosity required to power the H II region and keep the cloud at the observed large temperature (TK ≅33 K), is ∼105 L⊙ which is consistent with the infrared total flux from the present measurements and those from IRAS of 4x104 L⊙; this corresponds to the flux of ∼3 BO ZAMS stars. The details of the present work have appeared in the Revista Mexicana de Astronomía y Astrofísica, Volume 11, 83, 1985.
The aim of the study was to determine whether routine probiotic supplementation (RPS) with Lactobacillus rhamnosus GG (LGG) or Lactobacillus acidophilus +Lactobacillus bifidum is associated with reduced risk of necrotising enterocolitis (NEC)≥Stage II in preterm neonates born at ≤32 weeks’ gestation. We conducted a retrospective cohort study on the effect of probiotic supplementation in very low birth weight infants in our neonatal unit by comparing two periods: before and after supplementation. The incidence of NEC≥Stage II, late-onset sepsis and all-cause mortality was compared for an equal period ‘before’ (Period I) and ‘after’ (Period II) RPS with LGG or L. acidophillus+L. bifidum. Multivariate logistic regression analysis was conducted to adjust for relevant confounders. The study population was composed of 261 neonates (Period I v. II: 134 v. 127) with comparable gestation duration and birth weights. In <32 weeks, we observed a significant reduction in NEC≥Stage II (11·3 v. 4·8 %), late-onset sepsis (16 v. 10·5 %) and mortality (19·4 v. 2·3 %). The benefits in neonates aged ≤27 weeks did not reach statistical significance. RPS with LGG or L. acidophillus+L. bifidum is associated with a reduced risk of NEC≥Stage II, late-onset sepsis and mortality in preterm neonates born at ≤32 weeks’ gestation.
Animal health surveillance enables the detection and control of animal diseases including zoonoses. Under the EU-FP7 project RISKSUR, a survey was conducted in 11 EU Member States and Switzerland to describe active surveillance components in 2011 managed by the public or private sector and identify gaps and opportunities. Information was collected about hazard, target population, geographical focus, legal obligation, management, surveillance design, risk-based sampling, and multi-hazard surveillance. Two countries were excluded due to incompleteness of data. Most of the 664 components targeted cattle (26·7%), pigs (17·5%) or poultry (16·0%). The most common surveillance objectives were demonstrating freedom from disease (43·8%) and case detection (26·8%). Over half of components applied risk-based sampling (57·1%), but mainly focused on a single population stratum (targeted risk-based) rather than differentiating between risk levels of different strata (stratified risk-based). About a third of components were multi-hazard (37·3%). Both risk-based sampling and multi-hazard surveillance were used more frequently in privately funded components. The study identified several gaps (e.g. lack of systematic documentation, inconsistent application of terminology) and opportunities (e.g. stratified risk-based sampling). The greater flexibility provided by the new EU Animal Health Law means that systematic evaluation of surveillance alternatives will be required to optimize cost-effectiveness.
Corrosion is a worldwide, crucial problem that strongly affects natural and industrial environments, in particular the oil and gas industry. Natural gas (NG) is a source of energy in industrial, residential, commercial and electric applications. The abundance of NG in many countries augurs a profitable situation for the vast energy industry. NG is considered friendlier to the environment and with lesser greenhouse gas emissions as compared with other fossil fuels. In the last years, shale gas is increasingly exploited in U.S. and Europe, applying a hydraulic fracturing technique, for releasing gas from the bed rock by injection of saline water, acidic chemicals and sand to the wells. Various critical sectors of the NG industry infrastructure suffer from several types of corrosion: steel casings of production wells and their drilling equipment; gas conveying pipelines including pumps and valves; plants for regasification of liquefied natural gas (LNG) and municipal networks of NG distribution to the consumers. Practical technologies that minimize or prevent corrosion include selection of corrosion resistant engineering materials, cathodic protection, corrosion inhibitors, and application of external and internal paints, coatings and linings. Mexico is undergoing an intense reform process of the energy sector, that involves its oil, NG and electricity industries. Typical cases of corrosion management in the NG industry are presented based on the authors experience and knowledge.
The main purpose of this research was to establish the effectiveness of the V844 corrosion inhibitor for seawater on various metallic materials: carbon steel, aluminum and copper alloy at different concentrations via colloid formation. The changes in both physical and chemical properties of seawater, including pH, total hardness, alkalinity, total dissolved solids (TDS) and conductivity at different concentrations of V844 were assessed, too. The test procedure involves dissolving the V844 corrosion inhibitor powder provided by Magna International Private Limited in seawater to obtain a stock solution of 4% V844 in seawater, which was further diluted to obtain the remaining concentrations. The analysis of parameters begun when various metal species, polished beforehand, were placed into the solutions. The analysis was observed over a period of 26 days and a total of 9 sets of readings were obtained. From our observation and analysis, it was concluded that the inhibitor worked best at 0.05% concentration for carbon steel.
Concrete is a composite material, composed of cement, sand, gravel and water, reinforced with steel bars or mesh. It is used for the construction of infrastructure assets such as airports, dams, ports, bridges and road ways. Polymer concrete is a relative new material containing a thermosetting resin (instead of water) displaying improved mechanical strength, low permeability, greater corrosion resistance and higher durability. It is employed for new construction and old concrete reparation in the chemical, food, fertilizer, mine and civil industries. Polymer concrete pipe specimens, reinforced with glass-fibers were prepared and exposed in a salt spray (fog) chamber, operating with a NaCl solution, following ASTM standard B-117-11. The deterioration effects were assessed by testing the physical and mechanical properties, before and after the exposure in the spray chamber, in accordance with standard ASTM D3039-2013. Corrosion resistance was evaluated applying ASTM standard C876-2013. The result of this work are presented, illustrated and discussed.
Spatially resolved profiles of the Hα, and [NII] lines have been obtained with the Manchester echelle spectrometer combined with the 2.1 m San Pedro Mártir telescope over the bipolar lobes, the symmetric low ionization knots and the bright core of the planetary nebula KjPn 8. The lobes of this galactic bipolar nebula have the largest angular extent, 14′ × 4′, yet discovered.
Control of fire was a hallmark of developing human cognition and an essential technology for the colonisation of cooler latitudes. In Europe, the earliest evidence comes from recent work at the site of Cueva Negra del Estrecho del Río Quípar in south-eastern Spain. Charred and calcined bone and thermally altered chert were recovered from a deep, 0.8-million-year-old sedimentary deposit. A combination of analyses indicated that these had been heated to 400–600°C, compatible with burning. Inspection of the sediment and hydroxyapatite also suggests combustion and degradation of the bone. The results provide new insight into Early Palaeolithic use of fire and its significance for human evolution.
The optical and structural properties of co-doped HfO2 thin films with rare earth trivalent ions prepared by ultrasonic spray pyrolysis technique, are reported. An arrangement of multi-layer (Si-SiO2-HfO2:Eu3+-HfO2:Tb3+-HfO2:Tm3+-SiO2) were deposited on silicon substrates at temperatures from 400 to 550°C, using acetyl acetonates as precursory reagents. A refractive index value of 2.1 was determined by spectral ellipsometry. The surface morphology was obtained by AFM measurements. For 50 to 550 nm thickness films, an average roughness value of ∼56.8 Å was obtained for different substrate temperatures and grown deposition times. EDS measurements showed the presence of hafnium, and rare earths dopants as elemental composition. XPS measurements demonstrated that hafnium and rare earths oxidation species are formed at hafnium dioxide thin films. Photoluminescence emission spectra of multi-layer structures present characteristic emission peaks associated with Tb+3, Eu3+, and Tm3+ dopants. The results presented above motivate us to consider that these multilayer structures could be appropriate to be used as a rare earth host to improve optical emission.
Aluminum titanium oxynitride (TiAlNO) coatings were deposited on 316 steel substrates by the sputtering technique, varying the nitrogen flow from 2.5, 5, 7.5 to 10 sccm, and maintaining constant at 12 sccm the flow argon gas. We used targets of titanium and alumina with 99.995% purity. The hardness and tribological analyses were determined by Vickers microhardness and tribology (tribometer pin-disc), respectively. The results show that the coating with a nitrogen flow of 10 sccm had the lowest volumetric wear (2.047738693 mm3) and the maximum value of hardness (11.2 GPa). Analysis of X-ray diffraction evidenced the presence of three crystalline phases: Ti2N, Al2O3 and TiO2. It can be observed that by increasing the nitrogen flow, the portion of semi-Ti2N phase increases, Al2O3 decreases and TiO2 remains almost constant, and also producing a change in crystallographic orientation with reference to the Ti2N phase. Crystal grain sizes were estimated by X-ray diffraction Fourier line profile analysis using Warren–Averbach method. This analysis showed a grain size between 5 and 15 nm. Raman spectroscopy results show the presence of the TiO2 phase which corroborated the X-ray diffraction results.
Carbon nanotubes (CNTs) were synthesized by Chemical Vapor Deposition (CVD) from diethyl ether, butanol, hexane and ethyl acetate. A quartz tube with a stainless steel tube catalyst core with 0.019 m diameter and 0.6 m large formed the reactor. To avoid combustion, argon was used as the carrier gas. Time process ranged 30 to 60 min. The range of CNTs synthesis temperature was 680-850 °C for different precursors. Scanning Electron Microscopy micrographs have demonstrated tangled CNTs growth in all samples, thus presenting difficult length measurement. The CNTs diameters from diethyl ether are 45-200 nm, butanol diameter range from 55-230 nm, hexane diameter range is 50-130 nm and ethyl acetate range from 100 to 300 nm. Carbon content for all samples was higher than 93 %, CNTs from butanol showed carbon concentration up to 99%. FTIR, Raman and X-Ray Spectroscopies spectra for all samples demonstrated the characteristics signals present in carbon nanotubes. This research proposes a simple, effective and innovative method to synthesize CNTs by CVD on iron stainless steel catalyst in combination with diethyl ether, ethyl acetate, butanol and hexane as precursors by applying the principles of green chemistry, sustainability and its ease to be scaled.
Gold nanoparticles can be used as ultimate electrical materials for storing electrons or controlling their flow for the next generation nano-electronic devices. These particles are the core element of assemblies where the electrical current is reduced to the smallest possible since electrons are controlled one by one by using the Coulomb blockade phenomenon. We prepared colloidal gold nanoparticles beteween 4 and 15 nm and grafted them on a grafted organic monolayer (GOM) on silicon. GOM are highly ordered monolayers prepared by hydrosilylation of alkene molecules and subsequently modified with an amine group so that gold nanoparticles can be firmly immobilized on top of the layer. We discuss several electrical properties at a single electron level. Using the conductive tip of KPFM, we were also able to reveal the spontaneous charging behavior of the gold nanoparticles so that the local work function of a 10 nm gold nanoparticle is only 3.7 eV. By placing an STM tip above a nanoparticle, Coulomb blockade allows controlling the number of electrons simultaneously injected in the nanoparticle. This opens the way for new kinds of single electron memories or single electron transistors.
Using the 37-m telescope of the Haystack Observatory, we observed the (J,K)=(1,1) ammonia transition towards the suspected exciting sources of twelve regions with molecular or optical outflows: L1448, L1455, L1524 (Haro 6-10), RNO 43, HH 34, HH 38,43, Haro 4-255 FIR, NGC 2264 (HH 14-4,6), L43, R CrA, HH 32a (AS353A), and V1331 Cyg. We detected and mapped ammonia emission in nine of these regions.
The results of photometric and spectroscopic observations of dwarf novae are presented. The data were obtained during an international program of multiwavelength observations, held in 1986 February at several observatories, of dwarf novae during the first and subsequent days of outburst. During the campaign numerous dwarf novae were monitored in order to catch them in outburst. Preliminary results and analysis of some objects are reported elsewhere. A total of 30 dwarf novae were observed in the northern and southern hemispheres. Among them 37% were caught in outburst, including 10% on the rise to outburst and 17% in decline. Photometric observations were carried out in the UBVRI system and colour indexes were calculated.
Influenza vaccination has been shown to be the most effective preventive strategy to reduce influenza-related morbidity and mortality in high-risk groups. Despite healthcare personnel (HCP) being considered part of such high-risk groups, their vaccination coverage is low in Europe. In January 2012, we distributed an 18-question survey regarding influenza vaccination to HCP at Gregorio Marañon Paediatric Hospital, in Madrid, Spain. After we documented that only ~30% of HCP were vaccinated an educational programme was implemented in October 2012 before the next influenza season. In January 2013, the same survey delivered again to all HCP documented a significant increase in vaccination rates (from 30% to 40%, P = 0·007) mainly among physicians and for patients' protection. In summary we found that a simple and inexpensive educational programme significantly improved the uptake of influenza vaccination in HCP in our centre. Nevertheless, vaccination rates remained low, and broader and updated campaigns are needed to overcome perception barriers.
ST131 Escherichia coli is an emergent clonal group that has achieved successful worldwide spread through a combination of virulence and antimicrobial resistance. Our aim was to develop a mathematical model, based on current knowledge of the epidemiology of ESBL-producing and non-ESBL-producing ST131 E. coli, to provide a framework enabling a better understanding of its spread within the community, in hospitals and long-term care facilities, and the potential impact of specific interventions on the rates of infection. A model belonging to the SEIS (Susceptible–Exposed–Infected–Susceptible) class of compartmental models, with specific modifications, was developed. Quantification of the model is based on the law of mass preservation, which helps determine the relationships between flows of individuals and different compartments. Quantification is deterministic or probabilistic depending on subpopulation size. The assumptions for the model are based on several developed epidemiological studies. Based on the assumptions of the model, an intervention capable of sustaining a 25% reduction in person-to-person transmission shows a significant reduction in the rate of infections caused by ST131; the impact is higher for non-ESBL-producing ST131 isolates than for ESBL producers. On the other hand, an isolated intervention reducing exposure to antimicrobial agents has much more limited impact on the rate of ST131 infection. Our results suggest that interventions achieving a continuous reduction in the transmission of ST131 in households, nursing homes and hospitals offer the best chance of reducing the burden of the infections caused by these isolates.
Intrauterine growth restriction (IUGR) is associated with adverse perinatal outcomes and late-onset diseases in offspring. Eating disorders, voluntary caloric restriction and maternal undernutrition can all induce IUGR but a relevant model is required to measure all its possible consequences. In this work, pregnant rabbits were used as an IUGR model. Control females (n=4) received ad libitum diet throughout pregnancy, whereas underfed females (n=5) were restricted to 50% of their daily requirements. Offspring size was measured by ultrasonography and in vivo at birth. Hemodynamic features of the umbilical cords and middle cerebral arteries (systolic peak velocity, end diastolic velocity, pulsatility index and resistance index) were characterized by Doppler ultrasonography. At day 21, maternal underfeeding resulted in a significant reduction of fetal size (occipito-nasal length). At birth, the size of kits from the underfed group was significantly lower (lower crown-rump length, biparietal and transversal thoracic diameters) and a reduced weight with respect to the control group. Feed restriction altered blood flow perfusion compared with does fed ad libitum (significant higher systolic peak, time-averaged mean velocities and lower end diastolic velocity). Fetuses affected by IUGR presented with compensative brain-sparing effects when compared with the control group. In conclusion, the present study supports using rabbits and the underfeeding approach as a valuable model for IUGR studies. These results may help to characterize IUGR alterations due to nutrient restriction of mothers in future research.
In this globalized world, the spread of new, exotic and re-emerging diseases has become one of the most important threats to animal production and public health. This systematic review analyses conventional and novel early detection methods applied to surveillance. In all, 125 scientific documents were considered for this study. Exotic (n = 49) and re-emerging (n = 27) diseases constituted the most frequently represented health threats. In addition, the majority of studies were related to zoonoses (n = 66). The approaches found in the review could be divided in surveillance modalities, both active (n = 23) and passive (n = 5); and tools and methodologies that support surveillance activities (n = 57). Combinations of surveillance modalities and tools (n = 40) were also found. Risk-based approaches were very common (n = 60), especially in the papers describing tools and methodologies (n = 50). The main applications, benefits and limitations of each approach were extracted from the papers. This information will be very useful for informing the development of tools to facilitate the design of cost-effective surveillance strategies. Thus, the current literature review provides key information about the advantages, disadvantages, limitations and potential application of methodologies for the early detection of new, exotic and re-emerging diseases.