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To assess iodine status and its effects on maternal thyroid function throughout pregnancy.
In the present prospective cohort study, three urinary samples were requested for urinary iodine concentration (UIC) determinations in both the first and third gestational trimesters. Serum thyrotropin (TSH) and free thyroxine (FT4) were analysed in both trimesters and thyroid antibodies were assessed once.
Rio de Janeiro, Brazil.
First-trimester pregnant women (n 243), of whom 100 were re-evaluated during the third trimester.
Iodine sufficiency was found in the studied population (median UIC=216·7 µg/l). The first- and third-trimester median UIC was 221·0 and 208·0 µg/l, respectively. TSH levels (mean (sd)) were higher in the third trimester (1·08 (0·67) v. 1·67 (0·86) mIU/l; P<0·001), while FT4 levels decreased significantly (1·18 (0·16) v. 0·88 (0·12) ng/dl; P<0·001), regardless the presence of iodine deficiency (UIC<150 µg/l) or circulating thyroid antibodies. UIC correlated (β; 95% CI) independently and negatively with age (–0·43; –0·71, –0·17) and positively with multiparity (0·15; 0·02, 0·28) and BMI (0·25; 0·00, 0·50). Furthermore, median UIC per pregnant woman tended to correlate positively with TSH (0·07; –0·01, 0·14). Women with median UIC≥250 µg/l and at least one sample ≥500 µg/l throughout pregnancy had a higher risk of subclinical hypothyroidism (OR=6·6; 95% CI 1·2, 37·4).
In this cohort with adequate iodine status during pregnancy, excessive UIC was associated with an increased risk of subclinical hypothyroidism.
Reducing the risk of human immunodeficiency virus type 1 (HIV-1) transmission is still a public health priority. The development of effective control strategies relies on the quantification of the effects of prophylactic and therapeutic measures in disease incidence. Although several assays can be used to estimate HIV incidence, these estimates are limited by the poor performance of these assays in distinguishing recent from long-standing infections. To address such limitation, we have developed an assay to titrate p24-specific IgG3 antibodies as a marker of recent infection. The assay is based on a recombinant p24 protein capable to detect total IgG antibodies in sera using a liquid micro array and enzyme-linked immunosorbent assay. Subsequently, the assay was optimised to detect and titrate anti-p24 IgG3 responses in a panel of sequential specimens from seroconverters over 24 months. The kinetics of p24-specific IgG3 titres revealed a transient peak in the 4 to 5-month period after seroconversion. It was followed by a sharp decline, allowing infections with less than 6 months to be distinguished from older ones. The developed assay exhibited a mean duration of recent infection of 144 days and a false-recent rate of ca. 14%. Our findings show that HIV-1 p24-specific IgG3 titres can be used as a tool to evaluate HIV incidence in serosurveys and to monitor the efficacy of vaccines and other transmission control strategies.
Model predictive control (MPC) theory has gained attention with the recent increase in the processing power of computers that are now able to perform the needed calculations for this technique. This kind of control algorithms can achieve better results in trajectory tracking control of mobile robots than classical control approaches. In this paper, we present a review of recent developments in trajectory tracking control of mobile robot systems using model predictive control theory, especially when nonholonomicity is present. Furthermore, we point out the growth of the related research starting with the boom of mobile robotics in the 90s and discuss reported field applications of the described control problem. The objective of this paper is to provide a unified and accessible presentation, placing the classical model, problem formulations and approaches into a proper context and to become a starting point for researchers who are initiating their endeavors in linear/nonlinear MPC applied to nonholonomic mobile robots. Finally, this work aims to present a comprehensive review of the recent breakthroughs in the field, providing links to the most interesting and successful works, including our contributions to state-of-the-art.
Phosphorus (P) is an essential nutrient in livestock production, involved in most metabolic processes in the body, and with an impact on bone development and growth. Diet supplementation with P can improve productivity, but at excess levels the P utilization can be low, and the high P excretion will lead to environmental pollution (Tamminga, 2003). P supplementation also adds substantially to the cost of feed. Using the isotopic dilution technique (Vitti et al., 2000), we have studied the effect of different P levels in diet on P absorption and excretion in Brazilian sheep, and identified the level at which true P absorption saturates.
With the use of radioactive calcium (Ca) it is possible to study the kinetic aspects of Ca metabolism. Research in Brazil has been carried out to study mineral metabolism in sheep and cattle, especially phosphorus, by using isotope dilution techniques. However, there is very little information on Ca metabolism in sheep. The objective of this experiment was to study the effects of various Ca sources on the Ca metabolism in sheep by using isotope and balance techniques.
The timing and origin of Zika virus (ZIKV) introduction in Brazil has been the subject of controversy. Initially, it was assumed that the virus was introduced during the FIFA World Cup in June–July 2014. Then, it was speculated that ZIKV may have been introduced by athletes from French Polynesia (FP) who competed in a canoe race in Rio de Janeiro in August 2014. We attempted to apply mathematical models to determine the most likely time window of ZIKV introduction in Brazil. Given that the timing and origin of ZIKV introduction in Brazil may be a politically sensitive issue, its determination (or the provision of a plausible hypothesis) may help to prevent undeserved blame. We used a simple mathematical model to estimate the force of infection and the corresponding individual probability of being infected with ZIKV in FP. Taking into account the air travel volume from FP to Brazil between October 2013 and March 2014, we estimated the expected number of infected travellers arriving at Brazilian airports during that period. During the period between December 2013 and February 2014, 51 individuals travelled from FP airports to 11 Brazilian cities. Basing on the calculated force of ZIKV infection (the per capita rate of new infections per time unit) and risk of infection (probability of at least one new infection), we estimated that 18 (95% CI 12–22) individuals who arrived in seven of the evaluated cities were infected. When basic ZIKV reproduction numbers greater than one were assumed in the seven evaluated cities, ZIKV could have been introduced in any one of the cities. Based on the force of infection in FP, basic reproduction ZIKV number in selected Brazilian cities, and estimated travel volume, we concluded that ZIKV was most likely introduced and established in Brazil by infected travellers arriving from FP in the period between October 2013 and March 2014, which was prior to the two aforementioned sporting events.
Licuri (Syagrus coronate) cake is a biodiesel by-product used in ruminant feed as a beneficial energy source for supplementation in managed pastures. The objective was to evaluate the performance, digestibility, nitrogen balance, blood metabolites, ingestive behavior and diet profitability of eight crossbred Holstein (3/4)×Gyr (5/8) multiparous cows (480±25 kg BW and 100 days milking) grazing and supplemented with licuri cake partially replacing ground corn and soybean meal in concentrate (0, 200, 400 and 600 g/kg in dry matter (DM)), distributed in an experimental duplicated 4×4 Latin square design. Licuri cake partially replacing ground corn and soybean meal increased (P<0.01) the intake and digestibility of ether extract and decreased the non-fiber carbohydrates; however, there were no influences on the intakes of DM, CP, NDF and total digestible nutrients (TDN). The digestibilities of DM, CP and NDF were not influenced by licuri cake addition. There was a decrease trend on TDN digestibility (P=0.08). Licuri cake replacing ground corn and soybean meal in concentrate did not affect the intake; fecal, urinary and mammary excretions; N balance; and triglycerides concentrations. However, the blood urea nitrogen (P=0.04) concentration decreased with the licuri cakes inclusion in cow supplementation. There was an increasing trend for serum creatinine (P=0.07). Licuri cake inclusion did not affect body condition score, production, yield, protein, lactose, total solids and solid non-fat contents of milk and Minas frescal cheese. There was a linear decrease in average daily weight gain (g/day). The milk fat concentration and cheese fat production (P<0.1) presented a linear increase with partial replacement of ground corn and soybean meal with licuri cakes. The addition of licuri cake did not alter the time spent feeding, ruminating or idling. There was an increasing trend in NDF feeding efficiency (P=0.09). The replacing of ground corn and soybean meal with licuri cake up to 600 g/kg decreased the concentrate cost by US$0.45/cow per day. Licuri cake replacing corn and soybeans (400 g/kg) in concentrate promoted a profit of US$0.07/animal per day. Licuri cake is indicated to concentrate the supplementation of dairy cows with average productions of 10 kg/day at levels up to 400 g/kg in the concentrate supplement because it provides an additional profit of US$0.07/animal per day and increased milk and Minas frescal cheese fat without negative effects on productive parameters.
The present study investigated the impact of a western diet during gestation and lactation on the anthropometry, serum biochemical, blood pressure and cardiovascular autonomic control on the offspring. Male Wistar rats were divided into two groups according to their mother’s diet received: control group (C: 18% calories of lipids) and westernized group (W: 32% calories of lipids). After weaning both groups received standard diet. On the 60th day of life, blood samples were collected for the analysis of fasting glucose and lipidogram. Cardiovascular parameters were measured on the same period. Autonomic nervous system modulation was evaluated by spectrum analysis of heart rate (HR) and systolic arterial pressure (SAP). The W increased glycemia (123±2 v. 155±2 mg/dl), low-density lipoprotein (15±1 v. 31±2 mg/dl), triglycerides (49±1 v. 85±2 mg/dl), total cholesterol (75±2 v. 86±2 mg/dl), and decreased high-density lipoprotein (50±4 v. 38±3 mg/dl), as well as increased body mass (209±4 v. 229±6 g) than C. Furthermore, the W showed higher SAP (130±4 v. 157±2 mmHg), HR (357±10 v. 428±14 bpm), sympathetic modulation to vessels (2.3±0.56 v. 6±0.84 mmHg2) and LF/HF ratio (0.15±0.01 v. 0.7±0.2) than C. These findings suggest that a western diet during pregnancy and lactation leads to overweight associated with autonomic misbalance and hypertension in adulthood.
Among the solar proxies, κ1 Cet, stands out as potentially having a mass very close to solar and a young age. We report magnetic field measurements and planetary habitability consequences around this star, a proxy of the young Sun when life arose on Earth. Magnetic strength was determined from spectropolarimetric observations and we reconstruct the large-scale surface magnetic field to derive the magnetic environment, stellar winds, and particle flux permeating the interplanetary medium around κ1 Cet. Our results show a closer magnetosphere and mass-loss rate 50 times larger than the current solar wind mass-loss rate when Life arose on Earth, resulting in a larger interaction via space weather disturbances between the stellar wind and a hypothetical young-Earth analogue, potentially affecting the habitability. Interaction of the wind from the young Sun with the planetary ancient magnetic field may have affected the young Earth and its life conditions.
We discuss the v sin i distributions of main sequence B stars in galactic clusters in relation to stellar luminosity and to cluster metallicity. We show that evolutionary effects and/or dependence of initial v sin i distribution on stellar mass are important, so that a much larger sample and a wider metallicity range are required to detect any possible metallicity effect beyond doubt.
We present new observations of projected rotational velocities of main sequence B stars in the galactic clusters NGC 2439, NGC 3293, NGC 3766, NGC 4755, NGC 7160 and h & χ Persei. 257 stars have been observed with three instruments, 207 of which are presented here. Projected rotational velocities have been determined by least-squares fit to synthetic spectra. Our v sin i scale is compared with that of Slettebak et al. (1975).
Yams (Dioscorea spp.) are one of the main root and tuber crops in the world, especially within the species complex Dioscorea cayenensis/D. rotundata. Few studies have been conducted in Brazil with these species, including genetic diversity. The objective of this study was to characterize the genetic diversity of local varieties of D. cayenensis and D. rotundata using morphological and molecular markers, and provide information on the management and use of the crop by family farmers from different regions in Brazil. Thus, yam tubers were sampled from several municipalities in the South, Southeast and Northeast regions. Eighteen morphological traits and ten microsatellite loci were used to analyse 47 yam accessions (23 D. cayenensis and 24 D. rotundata). Species identification was carried out after field morphological evaluation. Spatial genetic analysis indicated significant structure among the local varieties, mostly between regions and species. Both cluster and Bayesian analyses showed a separation of the accessions into two distinct groups: group I with accessions originated from the Southeast region and group II with accessions originated from the Northeast region, while accessions from the South region were intermediate or included in either group. The results showed a separation between D. cayenensis and D. rotundata accessions in Brazil, and that D. cayenensis occurs predominantly in the Southeast region, while D. rotundata occurs in the Northeast region. Further studies with larger sampling would be welcome in order to confirm these findings. Also, this study highlights the importance of family farmers in the genetic diversity conservation of these species in Brazil.
Close-in massive planets transfer angular momentum to their host stars and influence their rotation through the torques associated with the tides raised on the star by the planet. For a star hosting a hot Jupiter, the limit of distance below which tidal torques cannot be neglected grows from a ~0.04 to a ~0.07 AU as the mass of the planet grows from 0.5 to 4MJup.
Symbionts in sponges must interact with the host immune system, and this can be mediated by immunomodulators. As the bases of the immune system in sponges resemble those of higher metazoans, it is possible that compounds from this microbiota show similar effects in other phyla. It is also known that several antibiotics, in special macrolides, can modulate many components of the immune response and sponges and their associated microorganisms are a rich source of these compounds. Therefore, we tested the immunosuppressive capacity of antibiotic substances produced by bacterial and fungal strains isolated from the Amazon freshwater sponge Metania reticulata. Fourteen bacterial and six fungal strains were obtained from samples of M. reticulata collected in the Negro River (Amazon Central Basin region), during the dry season. These cultures were monitored for natural antimicrobial activity, and two Bacillus strains (MERETb.761 and MERETb.762) and one fungus (MERETf.010) were selected. One Bacillus strain, MERETb.762, showed strong and specific antibiosis on Staphylococcus aureus and two fractions of its extract inhibited the degranulation of RBL–2H3 cells. The predicted formulas of these fractions were C12H6N4O8 and C25H4N2O6, both corresponding to nitroaromatic compounds.
Here we analyze the outcomes of unlimited access to a low-energy (LE) diet in dams and their offspring. At 3 weeks’ gestation, pregnant Wistar rats were divided into two groups: (1) the control group received a normoenergetic diet; and (2) the experimental group received the LE diet. In dams, lactation outcomes, food intake, body weight, plasma IGF-1, prealbumin, transferrin and retinol-binding protein levels were evaluated; in offspring, biometric and biochemical parameters and food intake were evaluated. No differences were observed during pregnancy. However, after lactation, dams that received the LE diet demonstrated significant reductions in body weight (P<0.05), plasma IGF-1 (P=0.01), prealbumin and visceral fat (P<0.001). Pups born to dams that received the LE diet demonstrated reduced body length and weight at weaning (P<0.001) and were lighter than the control animals at the end of the experimental period. Pups also demonstrated reduced plasma, low-density lipoprotein (P=0.04), triglycerides (P=0.002) and glucose levels (P<0.05), and differences were noted in visceral fat. These results indicate that feeding dams with LE diet during the reproductive period induces acute malnutrition and impairs the growth and development of offspring, as well as certain metabolic parameters.
κ1 Cet (HD 20630, HIP 15457, d = 9.16 pc, V = 4.84) is a dwarf star approximately 30 light-years away in the equatorial constellation of Cetus. Among the solar proxies studied in the Sun in Time, κ1 Cet stands out as potentially having a mass very close to solar and a young age. On this study, we monitored the magnetic field and the chromospheric activity from the Ca II H & K lines of κ1 Cet. We used the technique of Least-Square-Deconvolution (LSD, Donati et al. 1997) by simultaneously extracting the information contained in all 8,000 photospheric lines of the echelogram (for a linelist matching an atmospheric model of spectral type K1). To reconstruct a reliable magnetic map and characterize the surface differential rotation of κ1 Cet we used 14 exposures spread over 2 months, in order to cover at least two rotational cycles (Prot ~9.2 days). The Least Square deconvolution (LSD) technique was applied to detect the Zeeman signature of the magnetic field in each of our 14 observations and to measure its longitudinal component. In order to reconstruct the magnetic field geometry of κ1 Cet, we applied the Zeeman Doppler Imaging (ZDI) inversion method. ZDI revealed a structure in the radial magnetic field consisting of a polar magnetic spot. On this study, we present the fisrt look results of a high-resolution spectropolarimetric campaign to characterize the activity and the magnetic fields of this young solar proxy.
This work presents a surface study of monolithic vitreous (or glassy) carbon - MVC - obtained from vitreous carbon powder. Defective MVC pieces are crushed in a ball mill and size classified by sifting. The MVC powder is mixed with furfuryl-alcohol resin and compacted in a mould using a hydraulic press. Samples with different powder granulometries are produced in this way and carbonized in a furnace under nitrogen atmosphere. Complete carbonization of the “powder” is achieved in only one day and losses due to breakage of the pieces is less than 5%. These results compare very favorably with respect to traditional MVC production methods where full carbonization may require up to seven days and losses due to breakage can be as high as 70%. After carbonization, samples are sanded and polished. Surface roughness and microstructure are characterized by light microscopy. Porosity is quantified from micrographs using ImageJ software and nanometric height variations are measured by atomic force microscopy.