Biomass, Mineral Elements and Protein Contents of Six Freshwater Macrophytes from Ghana

The biomass, mineral elements and protein contents of six freshwater macrophytes found in Ghana are reported in this paper. The plants are Ceratophyllum demersum (a submerged plant), Eichhornia crassipes and Pistia stratiotes (free-floating plants), Echinochloa pyramidalis and Typha domingensis (emergent plants) and Nymphaea lotus (a floating-leaved plant). The fresh and dry weights of the plants were measured and the concentration of six elements: calcium, magnesium, nitrogen, phosphorus, potassium and sodium in the tissues of the plants were determined. Calcium and magnesium contents were determined by ethylenediamine tetraacetic acid (EDTA) titration, nitrogen by micro-Kjeldahl method, phosphorus as orthophosphate after reaction with molybdate by absorption spectrophotometry, and potassium and sodium by flame photometry. The fresh weight of the plants ranged from 22 to 57 t ha-1 while the dry weight ranged from 1.2 to 12.5 t ha-1. Mineral elements varied in the plants as follows: calcium, 0.6–2.2; magnesium, 0.4–2.7; nitrogen, 1.4–3.7; phosphorous, 0.2–0.8; potassium, 0.4–5.2; and sodium, 0.4–3.4 per cent dry weight. These values are within the ranges reported by other workers from comparable freshwater environments. The ethnobotany of the freshwater macrophytes studied was discussed

Water quality at the habitat of the Podostemaceae in Ghana

The water quality and river catchment characteristics of Ankasa, Asuboni and Pawnpawn rivers in Ghana where Podostemaceae grow were determined using standard methods. The altitude of the sites ranged from 100 to 290 mabove sea level. The catchment areas for the sites vary from 35 to 171 km2. Between 10–81% of the catchment areas of the sites are within forest reserves. The study showed that the Podostemaceae in Ghana inhabit rivers with the following range of physico-chemical characteristics: pH 6.7–7.3, calcium 2.2–16.0 mg l-1, ammonia-nitrogen 0.07–0. 90 mg l-1, chloride 6.8–38.0 mg l-1, electrical conductivity 26.4–138.0 mS cm-1, magnesium 0.4–9.7 mg l-1, nitrate-nitrogen 0.1–0.6 mg l-1, phosphate 0.01–0.30 mgl-1, silicate 0-21.4 mg l-1 and sulphate 1.5–20.8 mg l-1. The results indicate the quality of water at the habitat of Podostemaceae in Ghana

Prospectively Collected Characteristics of Adult Patients, Their Consultations and Outcomes as They Report Breathlessness When Presenting to General Practice in Australia

Introduction:Breathlessness is a subjective sensation, so understanding its impacts requires patients' reports, including prospective patient-defined breathlessness as a reason for presenting to general practitioners (GP).The aim of this study was to define the prevalence of breathlessness as a reason for GP consultations while defining the clinico-demographic factors of these patients and the characteristics and outcomes of those consultations.Methods:Using nine years of the Family Medicine Research Centre database of 100 consecutive encounters from 1,000 practices annually, the patient-defined reason for encounter 'breathlessness' was explored using prospectively collected data in people ≥18 years with clinical data coded using the International Classification for Primary Care V2. Dichotomous variables were analysed using chi square and 95% confidence intervals calculated using Kish's formula for a single stage clustered design.Results:Of all the 755,729 consultations collected over a nine year period from 1 April, 2000, 7255 included breathlessness as a reason for encounter (0.96%; 95% CI 0.93 to 0.99) most frequently attributed to chronic obstructive pulmonary disease. Only 48.3% of GPs saw someone reporting breathlessness. The proportion of consultations with breathlessness increased with age. Breathlessness trebled the likelihood that the consultation occurred in the community rather than the consulting room (p<0.0001) and increased 2.5 fold the likelihood of urgent referral to hospital (p<0.0001). Of those with breathlessness, 12% had undiagnosed breathlessness at the end of the consultation (873/7255) with higher likelihood of being younger females.Discussion:Breathlessness is a prevalent symptom in general practitioner. Such prevalence enables future research focused on understanding the temporal pattern of breathlessness and the longitudinal care offered to, and outcomes for these patients, including those who leave the consultation without a diagnosis. © 2013 Currow et al

The relationship between area poverty rate and site-specific cancer incidence in the United States

BACKGROUND The relationship between socioeconomic status and cancer incidence in the United States has not traditionally been a focus of population-based cancer surveillance systems. METHODS Nearly 3 million tumors diagnosed between 2005 and 2009 from 16 states plus Los Angeles were assigned into 1 of 4 groupings based on the poverty rate of the residential census tract at time of diagnosis. The sex-specific risk ratio of the highest-to-lowest poverty category was measured using Poisson regression, adjusting for age and race, for 39 cancer sites. RESULTS For all sites combined, there was a negligible association between cancer incidence and poverty; however, 32 of 39 cancer sites showed a significant association with poverty (14 positively associated and 18 negatively associated). Nineteen of these sites had monotonic increases or decreases in risk across all 4 poverty categories. The sites most strongly associated with higher poverty were Kaposi sarcoma, larynx, cervix, penis, and liver; those most strongly associated with lower poverty were melanoma, thyroid, other nonepithelial skin, and testis. Sites associated with higher poverty had lower incidence and higher mortality than those associated with lower poverty. CONCLUSIONS These findings demonstrate the importance and relevance of including a measure of socioeconomic status in national cancer surveillanc

Dynamics on expanding spaces: modeling the emergence of novelties

Novelties are part of our daily lives. We constantly adopt new technologies, conceive new ideas, meet new people, experiment with new situations. Occasionally, we as individuals, in a complicated cognitive and sometimes fortuitous process, come up with something that is not only new to us, but to our entire society so that what is a personal novelty can turn into an innovation at a global level. Innovations occur throughout social, biological and technological systems and, though we perceive them as a very natural ingredient of our human experience, little is known about the processes determining their emergence. Still the statistical occurrence of innovations shows striking regularities that represent a starting point to get a deeper insight in the whole phenomenology. This paper represents a small step in that direction, focusing on reviewing the scientific attempts to effectively model the emergence of the new and its regularities, with an emphasis on more recent contributions: from the plain Simon's model tracing back to the 1950s, to the newest model of Polya's urn with triggering of one novelty by another. What seems to be key in the successful modelling schemes proposed so far is the idea of looking at evolution as a path in a complex space, physical, conceptual, biological, technological, whose structure and topology get continuously reshaped and expanded by the occurrence of the new. Mathematically it is very interesting to look at the consequences of the interplay between the "actual" and the "possible" and this is the aim of this short review.Comment: 25 pages, 10 figure

Simulating Dynamical Features of Escape Panic

One of the most disastrous forms of collective human behaviour is the kind of crowd stampede induced by panic, often leading to fatalities as people are crushed or trampled. Sometimes this behaviour is triggered in life-threatening situations such as fires in crowded buildings; at other times, stampedes can arise from the rush for seats or seemingly without causes. Tragic examples within recent months include the panics in Harare, Zimbabwe, and at the Roskilde rock concert in Denmark. Although engineers are finding ways to alleviate the scale of such disasters, their frequency seems to be increasing with the number and size of mass events. Yet, systematic studies of panic behaviour, and quantitative theories capable of predicting such crowd dynamics, are rare. Here we show that simulations based on a model of pedestrian behaviour can provide valuable insights into the mechanisms of and preconditions for panic and jamming by incoordination. Our results suggest practical ways of minimising the harmful consequences of such events and the existence of an optimal escape strategy, corresponding to a suitable mixture of individualistic and collective behaviour.Comment: For related information see http://angel.elte.hu/~panic, http://www.helbing.org, http://angel.elte.hu/~fij, and http://angel.elte.hu/~vicse

Gamma-Ray Telescopes (in "400 Years of Astronomical Telescopes")

The last half-century has seen dramatic developments in gamma-ray telescopes, from their initial conception and development through to their blossoming into full maturity as a potent research tool in astronomy. Gamma-ray telescopes are leading research in diverse areas such as gamma-ray bursts, blazars, Galactic transients, and the Galactic distribution of aluminum-26.Comment: 11 pages, 6 figures/ in "400 Years of Astronomical Telescopes: A Review of History, Science and Technology", ed. B.R. Brandl, R. Stuik, & J.K. Katgert-Merkeli (Exp. Astron. 26, 111-122 [2009]

Two-layer laser clad coating as a replacement for chrome electroplating on forged steel

Chrome plating is one of many surface engineering techniques used for corrosion resistance, as well as a protective coating against surface damage in load bearing applications, with surface hardness in the region of 1000Hv. Laser cladding is an alternative hardfacing technique often chosen for corrosion resistance and for increasing the surface hardness of components, through thick clad coatings. The application of chrome plating and other similar surface engineering techniques for thick coatings can be inefficient and costly with practical process limitations. The objective of this case study was to investigate the feasibility of replacing the chrome plated layer of a rod mill pinion, made of forged steel, with a Nickel-based Tungsten-Carbide (Ni-WC) composite layer and an intermediate layer of Inconel 625. Mechanical properties were obtained using microhardness and nanoindentation techniques. Three-point bend tests were performed on test specimens from a pinion sample, in order to observe crack propagation resistance, a challenging task due to the curved geometry of the pinion sample and the difference in thickness between the existing and proposed coating layers. Crack development was captured, and plastic deformation was quantified with the use of Digital Image Correlation (DIC). In bending it was found that the bond between the composite coating, Inconel 625 and the steel substrate provided improved resistance to axial crack propagation, where the composite coating could withstand more than twice the bending tool displacement than the chrome electroplating

Chemical bonding in zeolites

A review is given with 28 refs. on the current status of chem. bonding of zeolites and AlPO's. Short range covalent bonding dominates, the tetrahedra have to be considered relatively rigid and the Si-O-Si bond angle flexible. Differences in energy of the SiO2 or AlPO4 polymorphs are small. The relative stability depends on a proper accounting of the small changes in electrostatic energy. The deprotonation energy is also mainly detd. by short range covalent interactions. These are only properly accounted for when full lattice relaxation is included in the calcns. Isomorphous substitution effects are also dominated by changes in covalent interaction energ

The skeletal phenotype of chondroadherin deficient mice

Chondroadherin, a leucine rich repeat extracellular matrix protein with functions in cell to matrix interactions, binds cells via their a2b1 integrin as well as via cell surface proteoglycans, providing for different sets of signals to the cell. Additionally, the protein acts as an anchor to the matrix by binding tightly to collagens type I and II as well as type VI. We generated mice with inactivated chondroadherin gene to provide integrated studies of the role of the protein. The null mice presented distinct phenotypes with affected cartilage as well as bone. At 3–6 weeks of age the epiphyseal growth plate was widened most pronounced in the proliferative zone. The proteome of the femoral head articular cartilage at 4 months of age showed some distinct differences, with increased deposition of cartilage intermediate layer protein 1 and fibronectin in the chondroadherin deficient mice, more pronounced in the female. Other proteins show decreased levels in the deficient mice, particularly pronounced for matrilin-1, thrombospondin-1 and notably the members of the a1-antitrypsin family of proteinase inhibitors as well as for a member of the bone morphogenetic protein growth factor family. Thus, cartilage homeostasis is distinctly altered. The bone phenotype was expressed in several ways. The number of bone sialoprotein mRNA expressing cells in the proximal tibial metaphysic was decreased and the osteoid surface was increased possibly indicating a change in mineral metabolism. Micro-CT revealed lower cortical thickness and increased structure model index, i.e. the amount of plates and rods composing the bone trabeculas. The structural changes were paralleled by loss of function, where the null mice showed lower femoral neck failure load and tibial strength during mechanical testing at 4 months of age. The skeletal phenotype points at a role for chondroadherin in both bone and cartilage homeostasis, however, without leading to altered longitudinal growth