An investigation into morphological and physiological approaches to screen maize (Zea mays L.) hybrids for drought tolerance

A pot experiment was carried out in completely randomized design (CRD) having three replications to screen out six maize (Zea mays L.) hybrids viz; FH-810, 32-F-10, FH-782, 32-B-33, YH-1898, Monsanto-6525, R-2315 and R-3304 for drought tolerance. The study was carried out with objective to screen hybrids, when exposed to drought on the early phase of their vegetative growth. The moisture treatments comprised of 100% field capacity (FC), 75% FC and 50% FC. The results exhibited that all these hybrids varied substantially in their stability against drought tolerance. However, the results pertaining to interaction of maize hybrids with three moisture levels of 100% FC, 75% FC and 50% FC revealed that 32-F-10 performed comparatively better in contrast to other maize hybrids in plant height (79.74 cm, 47.02 cm and 41.65 cm), leaf area per plant (865.10 cm2, 405.7 cm2 and 178.60 cm2), relative water contents (81.23%, 69.79% and 65.98%), at 100%, 75% and 50% FC, respectively, while YH-1898 hybrid produced lowest values of these attributes in almost all water levels. However, a better stomatal conductance (gs), photosynthetic rate (A) and transpiration rate (E) were exhibited by 32-F-10 while YH-1898 revealed least gas-exchange values among all hybrids. The experimental results revealed that under drought conditions 32-F-10 performed best than all other maize hybrids and could be used for further investigation to screen out other drought tolerant-maize hybrids for maximum production

Pulmonary function correlates with arterial stiffness in asthmatic patients

SummaryBackgroundAt the population level, asthma has been associated with chronic systemic inflammation as well as adverse cardiovascular outcomes.ObjectivesThe aim of this study was to investigate peripheral vascular hemodynamic variables of arterial stiffness (AS) and their relationship to pulmonary function tests in asthmatic patients.MethodsYoung asthmatic patients from the tertiary center for pulmonary diseases at the Barzilai Medical Center underwent pulmonary function evaluation and non-invasive radial artery hemodynamic profiling, pre- and post-exercise. Results were compared to age matched, non-asthmatic controls.Results23 young asthmatics and 41 controls, completed all evaluation points. Pulmonary flow parameters were significantly reduced in the asthma group at all points. There were no differences between groups in BMI, blood pressure, pulse rate or measurements of AS at baseline or after bronchodilation. The % predicted forced expiratory volume in the first second at baseline (FEV1%) in asthmatics was positively correlated with the small arteries elasticity index (SAEI) and negatively correlated with the systemic vascular resistance (SVR) in these patients. These correlations were not observed in non-asthmatic controls. In multifactorial regression FEV1 remained the major factor associated with measurements of AS in asthmatic patients, while gender was the only significant factor in non-asthmatic controls.ConclusionsSignificant correlations between measurements of AS and FEV1 in young asthmatics, suggest the presence of a common systemic, most likely inflammatory pathway involving both the cardiovascular and respiratory systems

BREEDING HIGH YIELDING DESI CHICKPEA (CICER ARIETINUM L.) GENOTYPES FOR THE AGRO-CLIMATIC CONDITIONS OF NWFP

Abstract Seeds of the 2 local desi chickpea varieties viz., Pb-91and C-44 were irradiated through gamma rays at 200 and 300 Gy doses during the year 2000. The M 1 to M 4 generations were raised fro

A random cell motility gradient downstream of FGF controls elongation of amniote embryos

Vertebrate embryos are characterized by an elongated antero-posterior (AP) body axis, which forms by progressive cell deposition from a posterior growth zone in the embryo. Here, we used tissue ablation in the chicken embryo to demonstrate that the caudal presomitic mesoderm (PSM) has a key role in axis elongation. Using time-lapse microscopy, we analysed the movements of fluorescently labelled cells in the PSM during embryo elongation, which revealed a clear posterior-to-anterior gradient of cell motility and directionality in the PSM. We tracked the movement of the PSM extracellular matrix in parallel with the labelled cells and subtracted the extracellular matrix movement from the global motion of cells. After subtraction, cell motility remained graded but lacked directionality, indicating that the posterior cell movements associated with axis elongation in the PSM are not intrinsic but reflect tissue deformation. The gradient of cell motion along the PSM parallels the fibroblast growth factor (FGF)/mitogen-activated protein kinase (MAPK) gradient1, which has been implicated in the control of cell motility in this tissue2. Both FGF signalling gain- and loss-of-function experiments lead to disruption of the motility gradient and a slowing down of axis elongation. Furthermore, embryos treated with cell movement inhibitors (blebbistatin or RhoK inhibitor), but not cell cycle inhibitors, show a slower axis elongation rate. We propose that the gradient of random cell motility downstream of FGF signalling in the PSM controls posterior elongation in the amniote embryo. Our data indicate that tissue elongation is an emergent property that arises from the collective regulation of graded, random cell motion rather than by the regulation of directionality of individual cellular movements

Geometry of River Networks II: Distributions of Component Size and Number

The structure of a river network may be seen as a discrete set of nested sub-networks built out of individual stream segments. These network components are assigned an integral stream order via a hierarchical and discrete ordering method. Exponential relationships, known as Horton's laws, between stream order and ensemble-averaged quantities pertaining to network components are observed. We extend these observations to incorporate fluctuations and all higher moments by developing functional relationships between distributions. The relationships determined are drawn from a combination of theoretical analysis, analysis of real river networks including the Mississippi, Amazon and Nile, and numerical simulations on a model of directed, random networks. Underlying distributions of stream segment lengths are identified as exponential. Combinations of these distributions form single-humped distributions with exponential tails, the sums of which are in turn shown to give power law distributions of stream lengths. Distributions of basin area and stream segment frequency are also addressed. The calculations identify a single length-scale as a measure of size fluctuations in network components. This article is the second in a series of three addressing the geometry of river networks.Comment: 16 pages, 13 figures, 4 tables, Revtex4, submitted to PR

Stratigraphic and petrographic study of the limestones of the La Tomita sector, in the municipality of Manaure-Cesar, Colombia

Introduction: In the La Tomita sector, municipality of Manaure (Cesar), outcrop a stratigraphic sequence of biomicrite limestones, biopelmicrites, pelmicrites, wackestones and packstones intercalated with shales, corresponding to the Lagunita Formation of the Cogollo Group.  Objective: To know the stratigraphic aspects, mineralogical composition and paleoenvironmental conditions of the outcropping limestones. Methodology: It proceeded with a lithostratigraphic description in the massif and taking samples in situ, twelve samples were extracted, of which seven were taken for petrographic analysis. Results: Wackestone facies with pelagic microfossils, bioclastic packstone, wackestone with worn mollusc bioclasts and wackestone with peloids were recognized. Petrographically, the limestones in this sector are made up of zircon, glauconite, sparite, micrite, pellets, planktonic foraminifera of the genus Heterohelix, of the Moremani species, and foraminifera of the genus Hedbergella and Trocoidea species. Bivalve fossils and some algae were also observed. Conclusions: These facies allowed establishing that these limestones were formed in an environment of medium platform with some external platform intervals, covering an area of facies of open sea.Introducción: En el sector La Tomita, municipio de Manaure (Cesar), aflora una secuencia estratigráfica de calizas biomicritas, biopelmicritas, pelmicritas, tipo wackestone y packstone intercalados con shales, correspondientes a la Formación Lagunita del Grupo Cogollo. Objetivo: Conocer los aspectos estratigráficos, composición mineralógica y condiciones paleoambientales de las calizas aflorantes Metodología: se procedió con una descripción litoestratigráfica en el macizo y toma de muestras in situ. Se extrajeron doce muestras, de la cuales se tomaron siete para análisis petrográfico. Resultados: Se reconocieron facies de wackestone con microfósiles pelágicos, packstone bioclásticos, wackestone con bioclastos de moluscos desgastados y wackestone con peloides; Petrográficamente las calizas en este sector están constituidas por circón, glauconita, esparita, micrita, pellets, foraminíferos planctónicos del género Heterohelix, de la especie Moremani y foraminíferos del género Hedbergella y especie Trocoidea; también se pudo observar fósiles de bivalvos y algunas algas. Conclusiones: estas facies permitieron establecer que estas calizas se formaron en un ambiente de plataforma media con algunos intervalos de plataforma externa, abarcando una zona de facie de mar abierto

Drought stress, its effect on maize production and development of drought tolerance through potassium application

Today, the world is facing many problems for crop production among them drought is the most dangerous. Here in this paper we have reviewed the threat of drought to food security in future especially related to maize production. Water is a cooling agent plays an important role in the functioning of plant body. Drought stress have deleterious effects on the seedling establishment, vegetative growth, photosynthesis, root growth, anthesis, anthesis-silking interval, pollination and grain formation in maize crop. The deleterious effects of drought can be mediated by application of nutrients which may enhance tolerance to drought stress. Among the nutrients potassium can enhance the tolerance in maize plant for drought stress. The application of potassium enhanced root growth and stem elongation. Similarly, potassium increased leaf water potential, osmotic potential and turgor potential under drought stress. Likewise, gas exchange parameters are improved by potassium. Application of potassium enhanced the photosynthetic rate and has better effect on other attributes. Most importantly potassium is greatly helpful in transport of sugars prepared in leaves to fruit. Potassium enhanced the yield and yield related parameters of maize crop. It seems quite important to study the role of potassium for increasing the plant tolerance to drought stress and to increase yield of crop under drought stress

Asymmetric first-price auctions with uniform distributions: analytic solutions to the general case

While auction research, including asymmetric auctions, has grown significantly in recent years, there is still little analytical solutions of first-price auctions outside the symmetric case. Even in the uniform case, Griesmer et al. (1967) and Plum (1992) find solutions only to the case where the lower bounds of the two distributions are the same. We present the general analytical solutions to asymmetric auctions in the uniform case for two bidders, both with and without a minimum bid. We show that our solution is consistent with the previously known solutions of auctions with uniform distributions. Several interesting examples are presented including a class where the two bid functions are linear. We hope this result improves our understanding of auctions and provides a useful tool for future research in auctions