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The Midwest is well known for agriculture, and Iowa is a leader in corn (Zea maysL.) and soybean (Glycine max[L.] Merr.) production. Fertilizers and chemical pesticides used to increase crop production can adversely affect the soil and water health. Midwest farmers also produce livestock and graze cattle on pastureland that can lead to excessive surface runoff and soil erosion. Establishing vegetative filter strips (VFSs) along the edge of farmland is one of the best management practices (BMPs) to reduce nutrient and sediment loss. However, studies have revealed that the classic VFS design along the length of an agricultural field does not adequately address nonuniform flow through the buffer. New designs are being researched to increase the efficiency of the VFS. In order to accurately implement new design strategies, the runoff flowpaths into the VFS need to be accurately modeled. This research assesses the performance of existing established VFS buffers of selected sites by modeling and analyzing the flow accumulation from the field into the VFS using geographic information system (GIS) and light detection and ranging (LiDAR) derived digital elevation model (DEM) 5 × 5 m data. This study also employed the new coefficient of flow interception (CFI) approach that improves the process of identifying areas where flow is concentrated and designing more efficient filter strips to account for concentrated runoff. In this study, the performance of VFS in three sites was evaluated by developing and using the CFI. Among the three sites, site 1 had very poor efficiency and no flow passes through the VFS, site 2 had low efficiency, and site 3 had excellent efficiency.

The adult bone marrow contains a population of multipotent mesenchymal stromal cells (MSCs), defined by plastic adherence, expression of stromal cell surface markers, and differentiation into mesenchymal lineages. There has been much interest in the possible therapeutic use of MSCs in the treatment of demyelinating diseases of the central nervous system. One therapeutic possibility is that these cells may be able to remyelinate when directly injected into the demyelinated spinal cord. Here we examine the effects of direct transplantation of green fluorescent protein (GFP)-labeled MSCs into a model of focal spinal cord demyelination induced by ethidium bromide. We demonstrate that direct intralesional injection of undifferentiated MSCs does not lead to remyelination. Furthermore, we report that transplanted MSCs migrate into areas of normal tissue, deposit collagen, and are associated with axonal damage. These findings support the need for further experimental evaluation of the safety and efficacy of direct parenchymal injection of MSCs into demyelinated lesions and highlight an important issue regarding potential clinical consequences of culture heterogeneity of MSCs between centers.

We report on a search for gravitational-wave bursts in data from the three LIGO interferometric detectors during their third science run. The search targets sub-second bursts in the frequency range 100-1100 Hz for which no waveform model is assumed and has a sensitivity in terms of the root-sum-square(rss) strain amplitude of hrss~ 10?20Hz?1/2. No gravitational-wave signals were detected in the eight days of analysed data.

This study reports on cognitive abilities and attainment in 29 children and 21 adults with Smith-Magenis syndrome. There were 13 boys and 16 girls aged 6 to 16 years, and nine men and 12 women aged 16 to 52 years. All had mild to severe learning disabilities with no differences overall between verbal and performance skills, but with a particular profile of cognitive strengths and weaknesses. Levels of attainment and of adaptive behaviour were strikingly low, and the group of adults emerged as much more dependent on carers than might have been expected from their general level of intellectual functioning. Reasons for this discrepancy are explored in terms of the severe behavioural difficulties characteristic of the syndrome.

In phase I clinical trials, experimental drugs are administered to healthy volunteers in order to establish their safety and to explore the relationship between the dose taken and the concentration found in plasma. Each volunteer receives a series of increasing single doses. In this paper a Bayesian decision procedure is developed for choosing the doses to give in the next round of the study, taking into account both prior information and the responses observed so far. The procedure seeks the optimal doses for learning about the dose-concentration relationship, subject to a constraint which reduces the risk of administering dangerously high doses. Individual volunteers receive more than one dose, and the pharmacokinetic responses observed are, after logarithmic transformation, treated as approximately normally distributed. Thus data analysis can be achieved by fitting linear mixed models. By expressing prior information as 'pseudo-data', and by maximizing over posterior distributions rather than taking expectations, a procedure which can be implemented using standard mixed model software is derived. Comparisons are made with existing approaches to the conduct of these studies, and the new method is illustrated using real and simulated data.To whom correspondence should be addressed.

We present exact solutions to U(1), SU(2), and SU(3) lattice gauge theories on a Kogut-Susskind lattice consisting of a single plaquette. We demonstrate precise equivalence between the U(1) theory and the harmonic oscillator on an infinite one-dimensional lattice, and between the SU(N) theory and anN-fermion Schrödinger equation.

1. Gastric emptying, gastric acid and pepsinogen secretion were assessed simultaneously in the conscious calf using the test meal and duodenal perfusion technique (Bell & Mostaghni, 1975).

There have been few studies of mental retardation amongst Australian Aboriginal children. Information about Aboriginal child mental retardation has usually been reported as a minor part of mental health surveys. A register of retarded children from tribally oriented Aboriginal communities in the Northern Territory of Australia was established to over come this deficiency. An examination of the age, sex and main conditions associated with registered cases was undertaken. The incidence and characteristics of retarded Aboriginals with few exceptions were found to be the same as those of retarded Europeans.

1. Gastric emptying and secretion were measured in conscious calves during alkaline or acid perfusion of the duodenum with simultaneous assessment of endogenous plasma somatostatin, gastrin and blood 5‐hydroxytryptamine (5‐HT).

Squid are the fastest swimming invertebrates, but the metabolic cost of speed, as assessed in swim-tunnels, is several-fold higher than in fish, making squid appear uncompetitive. Because oxygen consumption can be correlated with jet pressure, it is possible to monitor pressure and thus estimate performance and energy costs in nature. Tracking in course and depth gave a 3-D view of squid (Loligo forbesi) activities and costs for nearly three animal-weeks; five days of this included telemetry of jet pressures. These 2-5 kg loliginids hovered off-bottom most of the time, perhaps to avoid predation or damage to delicate skins. Hovering consumes about 50 ml O2 kg-1 h-1, twice as much as resting on bottom and half of overall average costs. Jet pressures were not well correlated with horizontal movements or tidal cycles, suggesting squid may “soar”; to reduce the cost of remaining in active current areas, acting as sit-and-wait predators. Maximal aerobic jetting was rare and usually associated with vertical climbing. Thus, these squid appear to have adopted a suite of natural behaviours which compensate for those aspects of their physiology which are least competitive with fishes and accentuate those which are most competitive.

The premature fracture of a jack body during pressure testing drew attention to the need to examine the integrity of the body in the presence of defects, from the point of view of fracture and fatigue, and to re-examine the adequacy of existing inspection measures. This assessment was based on fracture mechanics, and the methods used and conclusions drawn are described in the present paper.

The topological expansion suggests strong similarities between planar multiparticle production mechanisms in hadronic ande+ e- collisions. From this viewpoint, using hadronic production data, we predict correlations between rapidity gaps and charges of produced particles ine+ e- annihilations. Our prediction constitute a test of the similarity of these processes, independent of perturbative quantum chromodynamics.

The special needs of Aboriginal Australians have led to programme and service delivery changes over recent years. Behavioural and cultural factors are seen as relevant to these changes. There is still a lack of material available to field workers and administrators on which decision making and intervention skills can be developed. Three case studies are presented in an effort to overcome this deficit. The cases highlight the complexity of the issues involved.

Levels of endogenous somatostatin, gastric inhibitory polypeptide (GIP), glucagon and insulin were measured during gastric (abomasal) emptying in the conscious calf. Isotonic NaHCO3infused into the duodenum increased rates of emptying of a saline test meal and of gastric acid secretion, but had no effect on basal levels of blood glucose, somatostatin, GIP, insulin or glucagon. By contrast, intraduodenal infusion of 60 mm-HCl caused complete inhibition of gastric emptying, reduction of acid secretion, and an immediate increase in plasma somatostatin from 121·3 ± 9·4 (s.e.m.) to 286·3 ± 16·3 pg/ml (P<0·01) but levels of GIP, insulin, glucagon and glucose were unaltered. Intravenous injection of somatostatin (0·5 μg/kg) suppressed the antral electromyographic recording and gastric efflux so long as plasma somatostatin levels remained above approx. 200 pg/ml. This suggests that somatostatin can be released by intraduodenal acidification and that it inhibits gastric function by an endocrine effect. Since somatostatin retards gastric emptying it may therefore have an indirect role in nutrient homeostasis by limiting discharge of gastric chyme to the duodenum.

1. The relative importance of energy content and osmolality of the duodenal chyme in the feed‐back control of gastric emptying was investigated in the milk‐fed calf fitted with gastric (abomasal) and duodenal re‐entrant cannulae. 2. Duodenal infusion of isosmolal solutions, containing glucose, fructose or galactose, with a range of combustible energy content (0‐‐1.46 MJ/l.) resulted in the same high rate of emptying of test meals from the stomach (abomasum). Abomasal emptying was, therefore, not affected by the energy content of the duodenal infusate. 3. Gastric secretion of acid and pepsinogen, and the volume of gastric secretions produced were also unaffected by the energy content of isosomolal duodenal infusates. 4. The results of the study show that the combustible energy content of the intestinal chyme is not a direct determinant of gastric function and that total osmolality of the lumenal contents is the only parameter influencing duodenal receptors under the conditions of our experiments.

Background A double blind, placebo controlled study was undertaken to determine the effects of 104 weeks of intermittent cyclical etidronate therapy on bone mineral density (BMD) in patients undergoing long term oral corticosteroid therapy. Methods Forty nine patients of mean age 59 years on long term (>6 months) corticosteroid treatment were randomised to receive either 400 mg/day etidronate or placebo for 14 days followed in both groups by calcium (equivalent to 97 mg elemental Ca/day) with vitamin D (400 IU) for 76 days. The cycle was repeated a total of eight times over a period of two years. Dual energy x ray absorptiometry (DEXA) measurements of the lumbar spine and hip BMD and biochemical bone marker analyses were performed at baseline and every six months. Results Twenty six patients (10 men) received cyclical etidronate and 23 (nine men) received placebo. The mean (SD) dose of corticosteroid (prednisone or equivalent) at baseline in the etidronate group was 8 (4) mg/day and in the placebo group was 7 (4) mg/day. Most of the patients (43%) suffered from asthma. Forty one patients completed the study (22 in the etidronate group and 19 in the placebo group). All had a low BMD at entry and with treatment a significant difference was observed between groups in the mean (SE) percentage change from baseline in lumbar spine BMD at week 104 of 4.5 (1.65)% (p = 0.007) with a 95% confidence interval (CI) of 1.12 to 7.87%. No clinically or statistically significant treatment differences were observed at the hip or with bone markers. The incidence of adverse events was similar in the two groups. Conclusions The results show that intermittent cyclical etidronate therapy with calcium and vitamin D supplementation significantly increases lumbar spine BMD in patients with osteoporosis resulting from long term treatment with corticosteroids.

We consider in detail the gauge invariance constraints in Hamiltonian lattice gauge theories, focusing mainly on pureSU(2) Yang-Mills theory in 2+1 dimensions. We present matrix and partial differential representations of the Hamiltonian in which all gauge constraints have been taken fully into account. The applicability of this formulation is demonstrated on small lattices.

We examine theU(1) Hamiltonian lattice gauge theory in (2+1) and (3+1) dimensions. We set up a differential eigenvalue equation for the energy levels of the system, valid for all values of the coupling parameter. We show how the standard strong coupling results are retrieved, and also present a weak coupling solution which exhibits (unconfined) transverse photons as the phonons of the lattice. The lattice approach is thus seen to be appropriate for non-confining as well as for confining systems.

This paper describes the use of MALT for student teaching by the Mathematics Department of the University of Glasgow, outlines the development of a new MALT teaching unit, and compares the old and new MALT systems. For computer-assisted learning work, computer equipment and software products of the 1980s offer enormous advantages.

Measurements of oxygen consumption and mantle cavity pressure (P, kPa) of squid, Illex illecebrosus, of various masses (M,kg), swimming at various speeds (U, ms−1) in a tunnel respirometer yielded two relationships: Both jet frequency and peak pressures increase with increasing speed. Patterns varied considerably between individuals, but total area under the pressure curve (P) was well correlated with oxygen consumption and speed. A differential pressure transducer linked to an ultrasonic transmitter carrying average pressure data encoded on impulse frequency was designed to be carried inside the mantle cavity. It was tested in both the swim-tunnel and in video-taped free-swimming animals. The relationships above held over a range of speeds from 0 to 1·4ms−1, the maximum speed observed, indicating that such transducers could provide direct estimates of both the metabolic rates and activities of these pelagic carnivores in nature; their use to test hypotheses about several energy-saving strategies is discussed. Average thrusts, calculated from pressure data, are consistent with rigid body drag predictions and with overall locomotor efficiencies of 5 %, which are also consistent with the relative costs of transport and efficiency estimates for fish.

1. Gastric emptying, gastric acid and pepsinogen secretion were assessed simultaneously in the conscious calf using the test meal and duodenal perfusion technique (Bell & Mostaghni, 1975).

Pre-ruminant calves with gastric (abomasal) and duodenal cannulae were used to assess the effect of test meals of different temperatures on gastric emptying and secretion. Cross-over experiments with saline gastric meals and water duodenal infusate at 4°, 20° and 40° C were carried out. The temperature of the duodenal infusate had no effect of gastric function. Variation in the temperature of the meal resulted in a significant enhancement of gastric emptying at 4° compared with 40°C. Shivering always occurred when 4°C meals were instilled into the stomach and intermittently with 20°C meals, irrespective of the duodenal temperature.

Acid phosphatase activity is prominent in osteoclasts (bone resorbing cells) and has been implicated in the process of bone resorption, although its precise role is not understood. To study the distribution and activity of this enzyme, a quantitative cytochemical method has been developed using undecalcified fresh frozen sections of foetal rat calvariae. Sections were allowed to react with 3mmnaphthol ASBI phosphate at pH 5.0, and the reaction was stopped by rinsing in ice-cold tap water containing 50mmsodium fluoride. The reaction product was post-coupled to Fast Garnet at 4°C. The absorbance of areas of reaction product in the cytoplasm was measured using scanning and integrating microdensitometry. The initial velocity rate was maintained for up to 2 min at pH 5.0 with a substrate concentration of 3mmand a section thickness of 5 µm. Under these conditions reaction product was localized to osteoclasts and the surface of bone matrix beneath these cells. Activities in osteoblasts and chondrocytes were negligible. Osteoclastic acid phosphatase was almost totally inhibited by 10mmfluoride and reduced by 70% by 100mmtartrate.

Jet propulsion concentrates muscle power on a small volume of high-velocity fluid to give high thrust with low Froude efficiency. Proponents are typically escape artists with high maintenance costs. Nonetheless, oceanic squids depend primarily on jets to forage over large volumes of relatively unproductive ocean (low power density, Wm−3). A survey of locomotor performance among phyla and along an ‘evolutionary continuum’ of cephalopods (Nautilus, Sepia, Loligo and Illex) suggests that increasing speed and animal power density are required if animals are to compete effectively in environments of decreasing power density. Neutral buoyancy and blood oxygen reserves require unproductive volume, keeping drag high. Undulatory fins increase efficiency, but dependence on muscular hydrostats without rigid skeletal elements limits speed. Migratory oceanic squids show a remarkable range of anatomical, physiological and biochemical adaptations to sustain high speeds by maximizing power density. Muscle mitochondrial density increases 10-fold, but metabolic regulation is realigned to optimize both aerobic and anaerobic capacity. The origins of these adaptations are examined (as far as possible, and perhaps further) along the continuum leading to the most powerful invertebrates.

Tartrate‐resistant acid phosphatase activity (TRAPase) is widely used as a cytochemical marker to distinguish osteoclasts from macrophages and other related cell types. The degree of tartrate resistance, however, may depend on which reaction methods, tissues, or species are used. To investigate this further, we have measured the amount of cytochemical reaction product by microdensitometry. We compared osteoclast acid phosphatase (APase) activity in fresh frozen sections of neonatal rat calvaria using two different reaction methods; one is commonly employed for qualitative histochemistry and includes α naphthyl phosphate as substrate, simultaneous coupling to the chromagen Fast Garnet, and a 30‐minute reaction time (method A). The other may be used to measure enzyme reaction rates in cells in situ and employs conditions suitable for initial velocity kinetics, namely naphthol‐ASBI phosphate as substrate, post coupling to Fast Garnet, and a 2‐minute reaction time. Although enzyme reaction rates differed greatly between the two methods, significant inhibition of APase activity by tartrate was observed in calvarial osteoclasts (69% and 59% with methods A and B, respectively), osteoblasts, and spleen macrophages. Using method B, mouse calvarial osteoclasts had similar APase activity to that seen in the rat. Tartrate produced little inhibition in these mouse cells, in contrast to the observations made with rat tissue, but murine spleen macrophages were significantly tartrate sensitive (40% inhibition with tartrate). On this basis, conclusions regarding the cell specificity of TRAPase should be treated cautiously.

Perfusion of the stomach in the anaesthetized rat with saline acidified to pH 2.5 with hydrochloric acid induced a small but significant release of pepsinogen into the perfusate. This stumulus to secretion was unaffected by splanchnectomy but was abolished by vagotomy. It is concluded that to a modest degree acid secretion in the rat may stimulate pepsinogen secretion by a vagal pathway.

Leukocyte labelling in patients with sickle cell anaemia has been reported as difficult if not impossible due to the slow erythrocyte sedimentation rate (ESR) in these patients. This study investigated standard sedimentation methods in patients with sickle cell disease (n= 16) and compared the results obtained with those following changes in the amount and type of sedimenting agent used. Labelling with either 111In-oxine or 99Tcm-exametazime was attempted in only five patients. Replacement of the commonly used 6 Hetastarch (Hespan) with Dextran or Haemaccel did not improve leukocyte harvesting, even when the proportions used of these agents were increased. In most cases where standard procedures for leukocyte collection did not lead to harvesting of viable samples, it was possible to collect reasonably pure samples by increasing the proportion of Hespan used. It is possible to obtain adequate leukocyte labelling in the majority of sickle cell patients using a minor modification of standard techniques. In this group of patients a ratio of 8 ml of Hespan to 16 ml of blood should be used for cell separation. If this fails then donor cells, anti-granulocyte antibody labelling or HIG should be considered.