Dry matter production of Tanzania grass as a function of agrometeorological variables

The objective of this work was to develop and validate linear regression models to estimate the production of dry matter by Tanzania grass (Megathyrsus maximus, cultivar Tanzania) as a function of agrometeorological variables. For this purpose, data on the growth of this forage grass from 2000 to 2005, under dry-field conditions in Sao Carlos, SP, Brazil, were correlated to the following climatic parameters: minimum and mean temperatures, degree-days, and potential and actual evapotranspiration. Simple linear regressions were performed between agrometeorological variables (independent) and the dry matter accumulation rate (dependent). The estimates were validated with independent data obtained in Sao Carlos and Piracicaba, SP, Brazil. The best statistical results in the development and validation of the models were obtained with the agrometeorological parameters that consider thermal and water availability effects together, such as actual evapotranspiration, accumulation of degree-days corrected by water availability, and the climatic growth index, based on average temperature, solar radiation, and water availability. These variables can be used in simulations and models to predict the production of Tanzania grass.

New cosmic accelerating scenario without dark energy

We propose an alternative, nonsingular, cosmic scenario based on gravitationally induced particle production. The model is an attempt to evade the coincidence and cosmological constant problems of the standard model (Lambda CDM) and also to connect the early and late time accelerating stages of the Universe. Our space-time emerges from a pure initial de Sitter stage thereby providing a natural solution to the horizon problem. Subsequently, due to an instability provoked by the production of massless particles, the Universe evolves smoothly to the standard radiation dominated era thereby ending the production of radiation as required by the conformal invariance. Next, the radiation becomes subdominant with the Universe entering in the cold dark matter dominated era. Finally, the negative pressure associated with the creation of cold dark matter (CCDM model) particles accelerates the expansion and drives the Universe to a final de Sitter stage. The late time cosmic expansion history of the CCDM model is exactly like in the standard Lambda CDM model; however, there is no dark energy. The model evolves between two limiting (early and late time) de Sitter regimes. All the stages are also discussed in terms of a scalar field description. This complete scenario is fully determined by two extreme energy densities, or equivalently, the associated de Sitter Hubble scales connected by rho(I)/rho(f) = (H-I/H-f)(2) similar to 10(122), a result that has no correlation with the cosmological constant problem. We also study the linear growth of matter perturbations at the final accelerating stage. It is found that the CCDM growth index can be written as a function of the Lambda growth index, gamma(Lambda) similar or equal to 6/11. In this framework, we also compare the observed growth rate of clustering with that predicted by the current CCDM model. Performing a chi(2) statistical test we show that the CCDM model provides growth rates that match sufficiently well with the observed growth rate of structure.

Growth parameters and mortality rate of the Scomber japonicus peruanus (Jordan & Hubb, 1925) along the Peruvian coast, South Pacific

The growth parameters and the mortality rates of the Scomber japonicus peruanus (Chub mackerel) were studied based on monthly data of frequency of fork length classes obtained from commercial landings off the Peruvian coast from 1996 to 1998. The asymptotic body length and growth rate values obtained by the ELEFAN I (Electronic Length Frequency Analysis) ranged from 40.20 cm to 42.20 cm and from 0.38 to 0.39, respectively. The oscillation amplitude was 0.60; the Winter point values varied from 0.50 to 0.60 and the performance index from 2.79 to 2.84. The total mortality rate of the Chub mackerel obtained by the linearized catch curve oscillated between 1.68 and 3.35. The rate of fishing mortality varied from 1.16 to 2.78 and the exploitation rate from 0.68 to 0.84. The annual rate of natural mortality estimated by the Pauly`s method ranged from 0.52 to 0.53. The results obtained allow us to conclude that the longevity of the Chub mackerel was slightly over seven years.

Recruitment and growth variation of Ophionereis reticulata (Echinodermata: Ophiuroidea)

Two growth patterns are recognized in shallow-water ophiuroids: (I) slow growth and early reproductive maturity over a long life span and (2) rapid growth with a short life span. For species with the first pattern, both growth and recruitment would reflect a reproductive pattern with long periods of resting and spawning concentrated in certain months of the year. To evaluate this hypothesis, the recruitment, population dynamics, and growth of the intertidal brittle star Ophionereis reticulata were analyzed from January 2001 to December 2002 at the Baleciro Isthmus on the southeast coast of Brazil. The species shows an annual gametogenic cycle with spawning taking place in summer. Densities varied from 0.46 to 9.46 individuals m(-2). Density variations and seawater temperature were not significantly correlated. The population structure of O. reticulata was polymodal, with at least four co-occurring cohorts. Recruitment events were recorded in March 2001, October 2001, January 2002, and September 2002. As indicated by the asymptote size (D(infinity)=11.47 mm +/- 1.46), growth constant (K=0.42 year(-1)+/- 0.12), and oscillation index (C=0.97 +/- 0.51), the growth pattern of O. reticulata seems to be based on high survivorship of juveniles and adults, where sexual maturity is reached at a small size with rapid growth in the first 2 years of life. A low level of settlement is to be expected based on these data; however, there must be a minimum successful survivorship and development for juveniles and adults. Another explanation for the lack of small individuals (disc diameter <1.0 mm) could be that recruitment is located in a different area and a post-settlement migration might be involved in the maintenance of the population.

Relationship between elastic and mechanical properties of dental ceramics and their index of brittleness

The purpose of the study was to verify the effects of a number of materials' parameters (crystalline content; Young's modulus, E; biaxial flexure strength, sigma(i); Vickers hardness, VH; fracture toughness, K-Ic; fracture surface energy, gamma(f); and index of brittleness, B) on the brittleness of dental ceramics. Five commercial dental ceramics with different contents of glass phase and crystalline particles were studied: a vitreous porcelain (VM7/V), a porcelain with 16 vol% leucite particles (d.Sign/D), a glass-ceramic with 29 vol% leucite particles (Empress/E1), a glass-ceramic with 58 vol% lithium-disilicate needle-like particles (Empress 2/E2), and a glass-infiltrated alumina composite with 65 vol% crystals (In-Ceram Alumina/IC). Discs were constructed according to manufacturers' instructions, ground and polished to final dimensions (12 mm x 1.1 mm). Elastic constants were determined by ultrasonic pulse-echo method. sigma(i) was determined by piston-on-3-balls method in inert condition. VH was determined using 19.6 N load and K-Ic was determined by indentation strength method. gamma(f) was calculated from the Griffith-Irwin relation and B by the ratio of HV to K-Ic. IC and E2 showed higher values of sigma(i), E, K-Ic and gamma(f), and lower values of B compared to leucite-based glass-ceramic and porcelains. Positive correlations were observed for sigma(i) versus K-Ic, and K-Ic versus E-1/2, however, E did not show relationship with HV and B. The increase of crystalline phase content is beneficial to decrease the brittleness of dental ceramics by means of both an increase in fracture surface energy and a lowering in index of brittleness. (C) 2012 Elsevier Ltd and Techna Group Sri. All rights reserved.

Predicting pH at birth in pregnancies with abnormal pulsatility index and positive end-diastolic velocity in the umbilical artery

Objectives: To identify potential associations between fetal surveillance tests and acidosis at birth in pregnancies with abnormal but positive end-diastolic velocity in the umbilical artery. Methods: A prospective case-control study [group 1: pH < 7.2; group 2: pH >= 7.2] including 46 fetuses with abnormal but positive end-diastolic velocity in the umbilical artery was conducted between February 2007 and March 2009. Outcome variables were evaluated by univariate analysis and compared between the two groups. Clinically relevant and statistically significant variables were analyzed by logistic regression. Results: Abnormal nonstress test, presence of deceleration, and absent fetal breathing movements were statistically significant. Logistic regression analysis revealed that fetal heart rate (FHR) deceleration in the nonstress test is the only predictor of fetal acidosis at birth (p = 0.024; OR = 8.2; 95% CI: 1.2-52). Conclusions: In fetuses with positive end-diastolic flow velocity, acute variables of the antenatal surveillance tests are correlated with acidosis at birth and FHR deceleration in the nonstress test is the only predictor of fetal acidosis.

Predicting Growth of Panicum maximum: An Adaptation of the CROPGRO-Perennial Forage Model

Warm-season grasses are economically important for cattle production in tropical regions and tools to aid in management and research on these forages would be highly beneficial both in research and the industry. This research was conducted to adapt the CROPGRO-Perennial Forage model to simulate growth of the tropical species guineagrass (Panicum maximum Jacq. cv. 'Tanzania') and to describe model adaptation for this species. To develop the CROPGRO parameters for this species, we began with values and relationships reported in the literature. Some parameters and relationships were calibrated by comparison with observed growth, development, dry matter accumulation, and partitioning during a 17-mo experiment with Tanzania guineagrass in Piracicaba, SP, Brazil. Compared with starting parameters for palisadegrass [Brachiaria brizantha (A. Rich.) Stapf. cv. 'Xaraes'], dormancy effects of the perennial forage model had to be minimized, partitioning to storage tissue or root decreased, and partitioning to leaf and stem increased to provide for more leaf and stem growth and less root. Parameters affecting specific leaf area and senescence of plant tissues were improved. After these changes were made to the model, biomass accumulation was better simulated, mean predicted herbage yield was 6576 kg ha(-1), averaged across 11 regrowth cycles of 35 (summer) or 63 d (winter), with a RMSE of 494 kg ha(-1) (Willmott's index of agreement d = 0.985, simulated/observed ratio = 1.014). The model also gave good predictions against an independent data set, with similar RMSE, ratio, and d. The results of the adaptation suggest that the CROPGRO model is an efficient tool to integrate physiological aspects of guineagrass and can be used to simulate growth.

Climatic oscillations shape the phylogeographical structure of Atlantic Forest fire-eye antbirds (Aves: Thamnophilidae)

In the present study, mitochondrial (mt)DNA sequence data were used to examine the genetic structure of fire-eye antbirds (genus Pyriglena) along the Atlantic Forest and the predictions derived from the river hypothesis and from a Last Glacial Maximum Pleistocene refuge paleomodel were compared to explain the patterns of genetic variation observed in these populations. A total of 266 individuals from 45 populations were sampled over a latitudinal transect and a number of phylogeographical and population genetics analytical approaches were employed to address these questions. The pattern of mtDNA variation observed in fire-eye antbirds provides little support for the view that populations were isolated by the modern course of major Atlantic Forest rivers. Instead, the data provide stronger support for the predictions of the refuge model. These results add to the mounting evidence that climatic oscillations appear to have played a substantial role in shaping the phylogeographical structure and possibly the diversification of many taxa in this region. However, the results also illustrate the potential for more complex climatic history and historical changes in the geographical distribution of Atlantic Forest than envisioned by the refuge model. (c) 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105, 900824.

Determinants of linear growth from infancy to school-aged years: a population-based follow-up study in urban Amazonian children

Background: Although linear growth during childhood may be affected by early-life exposures, few studies have examined whether the effects of these exposures linger on during school age, particularly in low-and middle-income countries. Methods: We conducted a population-based longitudinal study of 256 children living in the Brazilian Amazon, aged 0.1 y to 5.5 y in 2003. Data regarding socioeconomic and maternal characteristics, infant feeding practices, morbidities, and birth weight and length were collected at baseline of the study (2003). Child body length/height was measured at baseline and at follow-up visits (in 2007 and 2009). Restricted cubic splines were used to construct average height-for-age Z score (HAZ) growth curves, yielding estimated HAZ differences among exposure categories at ages 0.5 y, 1 y, 2 y, 5 y, 7 y, and 10 y. Results: At baseline, median age was 2.6 y (interquartile range, 1.4 y-3.8 y), and mean HAZ was -0.53 (standard deviation, 1.15); 10.2% of children were stunted. In multivariable analysis, children in households above the household wealth index median were 0.30 Z taller at age 5 y (P = 0.017), and children whose families owned land were 0.34 Z taller by age 10 y (P = 0.023), when compared with poorer children. Mothers in the highest tertile for height had children whose HAZ were significantly higher compared with those of children from mothers in the lowest height tertile at all ages. Birth weight and length were positively related to linear growth throughout childhood; by age 10 y, children weighing >3500 g at birth were 0.31 Z taller than those weighing 2501 g to 3500 g (P = 0.022) at birth, and children measuring >= 51 cm at birth were 0.51 Z taller than those measuring <= 48 cm (P = 0.005). Conclusions: Results suggest socioeconomic background is a potentially modifiable predictor of linear growth during the school-aged years. Maternal height and child's anthropometric characteristics at birth are positively associated with HAZ up until child age 10 y.

Growth standards of patients with Noonan and Noonan-like syndromes with mutations in the RAS/MAPK pathway

Noonan syndrome (NS) and Noonan-like syndromes (NLS) are autosomal dominant disorders caused by heterozygous mutations in genes of the RAS/MAPK pathway. The aim of the study was to construct specific growth charts for patients with NS and NLS. Anthropometric measurements (mean of 4.3 measurements per patient) were obtained in a mixed cross-sectional and longitudinal mode from 127 NS and 10 NLS patients with mutations identified in PTPN11 (n?=?90), SOS1 (n?=?14), RAF1 (n?=?10), KRAS (n?=?8), BRAF (n?=?11), and SHOC2 (n?=?4) genes. Height, weight, and body mass index (BMI) references were constructed using the lambda, mu, sigma (LMS) method. Patients had birth weight and length within normal ranges for gestational age although a higher preterm frequency (16%) was observed. Mean final heights were 157.4?cm [-2.4 standard deviation score (SDS)] and 148.4?cm (-2.2?SDS) for adult males and females, respectively. BMI SDS was lower when compared to Brazilian standards (BMI SDS of -0.9 and -0.5 SDS for males and females, respectively). Patients harboring mutations in RAF1 and SHOC2 gene were shorter than other genotypes, whereas patients with SOS1 and BRAF mutations had more preserved postnatal growth. In addition, patients with RAF1 and BRAF had the highest BMI whereas patients with SHOC2 and KRAS mutations had the lowest BMI. The present study established the first height, weight, and BMI reference curves for NS and NLS patients, based only on patients with a proven molecular cause. These charts can be useful for the clinical follow-up of patients with NS and NLS. (c) 2012 Wiley Periodicals, Inc.

Do Higher Temperatures Increase Growth in the Nocturnal Gecko Homonota darwini (Gekkota: Phyllodactylidae)? A Skeletochronological Assessment Analyzed at Temporal and Geographic Scales

Recent studies predict that several lineages of tropical animals are at particular risk given current estimates of global climate change. Yet, much uncertainty exists on the effects of climate shifts in ectothermic species from cool temperate regions such as Patagonia. In this study, we focus on the impact of environmental temperature on growth, age at sexual maturity, and life-span of the Patagonian gecko Homonota darwini. Skeletochronological methods were used to assess the bone growth rates Of individuals from three populations at different geographic and temporal scales: two populations from Chubut (warm site; 1941 and 2010) and one population from Rio Negro (cold site; 1997-1998). Populations displayed similar bone arrangement and the growth patterns fit a von Bertalanffy curve. Three populations attained reproductive size at a minimum age of 3 yr, but at the cold site two specimens were shown to mature in 4 yr. We found no differences in juvenile growth rates in body size or bone zone width between juveniles of 1 to 3 yr of age from the 1941 warm site and the 2010 warm site. However, these traits appeared to be higher at these two warm sites than at the cold site, which is consistent with the climatic differences among the three localities. Our results suggest that higher temperatures positively affect growth, denoting that global warming might benefit H. darwini, especially the southern populations.

Factors Associated with Height Catch-Up and Catch-Down Growth Among Schoolchildren

In developed countries, children with intrauterine growth restriction (IUGR) or born preterm (PT) tend to achieve catch-up growth. There is little information about height catch-up in developing countries and about height catch-down in both developed and developing countries. We studied the effect of IUGR and PT birth on height catch-up and catch-down growth of children from two cohorts of liveborn singletons. Data from 1,463 children was collected at birth and at school age in Ribeirao Preto (RP), a more developed city, and in Sao Luis (SL), a less developed city. A change in z-score between schoolchild height z-score and birth length z-score >= 0.67 was considered catch-up; a change in z-score <=-0.67 indicated catch-down growth. The explanatory variables were: appropriate weight for gestational age/PT birth in four categories: term children without IUGR (normal), IUGR only (term with IUGR), PT only ( preterm without IUGR) and preterm with IUGR; infant's sex; maternal parity, age, schooling and marital status; occupation of family head; family income and neonatal ponderal index (PI). The risk ratio for catch-up and catch-down was estimated by multinomial logistic regression for each city. In RP, preterms without IUGR (RR = 4.13) and thin children (PI<10th percentile, RR = 14.39) had a higher risk of catch-down; catch-up was higher among terms with IUGR (RR = 5.53), preterms with IUGR (RR = 5.36) and children born to primiparous mothers (RR = 1.83). In SL, catch-down was higher among preterms without IUGR (RR = 5.19), girls (RR = 1.52) and children from low-income families ( RR = 2.74); the lowest risk of catch-down (RR = 0.27) and the highest risk of catch-up (RR = 3.77) were observed among terms with IUGR. In both cities, terms with IUGR presented height catch-up growth whereas preterms with IUGR only had height catch-up growth in the more affluent setting. Preterms without IUGR presented height catch-down growth, suggesting that a better socioeconomic situation facilitates height catch-up and prevents height catch-down growth.

Effects of light intensity and temperature on Cylindrospermopsis raciborskii (Cyanobacteria) with straight and coiled trichomes: growth rate and morphology

Cylindrospermopsis raciborskii (Woloszynska) Seenayya et Subba Raju (Ordem Nostocales) is one of the most troublesome bloom-forming species in Brazil. Understanding the population dynamics of the different morphotypes of C. raciborskii (straight and coiled) could assist in the prediction of favourable conditions for the proliferation of this potentially toxin-producing species. The aim of the present study was to assess the effects of two different light intensities and temperatures on the growth rate and morphology of the trichomes of the straight and coiled morphotypes. For such, two non-toxin producing strains of C. raciborskii were used - one with a coiled trichome (ITEP31) and another with a straight trichome (ITEP28). The strains were cultured in BG-11 medium in a climatic chamber under controlled conditions. Two light intensities (30 and 90 mu mol.m(-2).s(-1)) were combined at temperatures of 21 and 31 degrees C and the growth rate and morphological changes were analysed. The morphotypes responded differently to the different temperatures and light intensities. Both strains exhibited faster growth velocities when submitted to higher light intensity and temperature. The lower temperature and higher luminosity hampered the development of both strains. Variations in cellular morphology and an absence of akinetes in both strains were related to the lower temperature (21 C). The coiled morphotype demonstrated considerable phenotype plasticity, changing the morphology of trichome throughout its growth curve. Although molecular analysis does not sustain the separation of the morphotypes as distinct species, their different eco-physiological responses should be considered further knowledge of extreme importance for the population control of these potentially toxic organisms.

Vertical growth of mini watermelon according to the training height and plant density

The watermelon is traditionally cultivated horizontally on the ground. The cultivars of small fruits (1 to 3 kg), which reach better market prices, are also being grown in a greenhouse, where the plants are trained upward on vertical supports, with branches pruning and fruits thinning. These practices make possible an increase of the plant density, fruit quality and yield compared to the traditional growth system. The aim of this experiment was to evaluate the influence of three training heights (1.7, 2.2 and 2.7 m) and two planting densities (3.17 and 4.76 plants m-2) over the productive and qualitative characteristics of mini watermelon "Smile" cultivated in greenhouse. The pruning was done at 43, 55 and 66 days after transplanting (DAT), when the plant height reached 1.7, 2.2 and 2.7 m, respectively. The dry mass of branches, petioles, leaves and total were affected by the training height, where the highest values were obtained by the plants pruned at 2.2 and 2.7 m. Leaf area, specific leaf area and leaf area index were not affected by the height of the plants. The training height of 2.7 m raised the total yield, however, marketable yield, average fruit mass and all the quality characteristics did not differ significantly from those obtained by the training height of 2.2 m. Regarding to plant density, the best option was 4.76 plants m-2, due to the increasing of marketable yield in 37.4% without reducing the average weight of fruits.

Lung morphology and growth of rats exposed to tobacco smoke and alcohol

PURPOSE: Investigate the morphological effects of chronic exposure to tobacco smoke inhalation and alcohol consumption on the lungs and on the growth of rats. METHODS: Sixty male Wistar rats were divided into four groups: control, tobacco, alcohol, tobacco + alcohol, for a period of study 260 days. Morphological analysis was conducted by optical and electron microscopy. Rat growth was investigated by measuring the snout-anus length, body mass index and body weight. RESULTS: The three groups exposed to the drugs presented lower growth and lower weight than the control group. The percentages of alveolitis, bronchiolitis and the mean alveolar diameter were greater, particularly in the groups exposed to tobacco smoke, but were not significantly different from the control group. Electron microscopy revealed more intense apoptotic and degenerative lesions in the smoking group, while degenerative lesions in the lamellar bodies were more intense with the association of both drugs. CONCLUSIONS: This experimental model showed morphological alterations observed by electron microscopy, principally due to tobacco smoke exposure. Alcohol and tobacco hindered the growth of rats, such that tobacco showed a greater effect on body length and alcohol on body weight.