The release of silicon from amorphous silica and rice straw in Sri Lankan soils

Silicon release from rice straw and amorphous silica when shaken in solution with five Sri Lankan soils was studied indirectly using sorption isotherms and changes in concentration and directly using straw in dialysis bags examined using electron microscopy. The aim was to further our understanding of the processes and factors affecting the release of straw-Si in soils and its availability to rice. The soils (alfisols and ultisols) shaken with 0.1 M NaCl (5 g per 125 mL for 250 days) produced concentrations of 1 - 4 mg L-1 of monosilicic acid-Si. Amorphous silica added to these suspensions (36.5 mg, containing 17 mg Si) raised the concentrations to 20 - 40 mg L-1, and added rice straw (0.5 g, containing 17 mg Si) gave 10 - 25 mg L-1. Sorption isotherms (7 days equilibrations) were used to calculate from the concentrations the amounts of Si released ( 24 - 38% and 8 - 21%, respectively). Both materials gave about 40 mg L-1 of monosilicic acid-Si plus 30 mg L-1 of disilicic acid-Si when shaken in solution alone (5 g per 125 mL). Straw in dialysis bags ( 0.5 g per 25 mL in 0.1 M NaCl) was shaken in soil suspension ( 5 g per 100 mL) for 60 days. Similar concentrations and releases were measured to those obtained above. About one fifth of the mass of straw was lost by decomposition in the first 15 days. A chloroform treatment prevented decomposition, but Si release was unaffected. Disintegration continued throughout the experiments, with phytoliths being exposed and dissolved. Compared to the rate of release from straw into solution without soil, the release of Si into soil suspensions was increased during the first 20 days by adsorption on the soil, but was then reduced probably through the effect of Fe and Al on the phytolith surfaces. The extent of this blocking effect varied between soils and was not simply related to soil pH.

Laurentide ice streaming on the Canadian Shield: A conflict with the soft-bedded ice stream paradigm?

Elucidating the controls on the location and vigor of ice streams is crucial to understanding the processes that lead to fast disintegration of ice flows and ice sheets. In the former North American Laurentide ice sheet, ice stream occurrence appears to have been governed by topographic troughs or areas of soft-sediment geology. This paper reports robust evidence of a major paleo-ice stream over the northwestern Canadian Shield, an area previously assumed to be incompatible with fast ice flow because of the low relief and relatively hard bedrock. A coherent pattern of subglacial bedforms (drumlins and megascalle glacial lineations) demarcates the ice stream flow set, which exhibits a convergent onset zone, a narrow main trunk with abrupt lateral margins, and a lobate terminus. Variations in bedform elongation ratio within the flow set match theoretical expectations of ice velocity. In the center of the ice stream, extremely parallel megascalle glacial lineations tens of kilometers long with elongation ratios in excess of 40:1 attest to a single episode of rapid ice flow. We conclude that while bed properties are likely to be influential in determining the occurrence and vigor of ice streams, contrary to established views, widespread soft-bed geology is not an essential requirement for those ice streams without topographic control. We speculate that the ice stream acted as a release valve on ice-sheet mass balance and was initiated by the presence of a proglacial lake that destabilized the ice-sheet margin and propagated fast ice flow through a series of thermomechanical feedbacks involving ice flow and temperature.

The release of silicon from amorphous silica and rice straw in Sri Lankan soils

Silicon release from rice straw and amorphous silica when shaken in solution with five Sri Lankan soils was studied indirectly using sorption isotherms and changes in concentration and directly using straw in dialysis bags examined using electron microscopy. The aim was to further our understanding of the processes and factors affecting the release of straw-Si in soils and its availability to rice. The soils (alfisols and ultisols) shaken with 0.1 M NaCl (5 g per 125 mL for 250 days) produced concentrations of 1 - 4 mg L-1 of monosilicic acid-Si. Amorphous silica added to these suspensions (36.5 mg, containing 17 mg Si) raised the concentrations to 20 - 40 mg L-1, and added rice straw (0.5 g, containing 17 mg Si) gave 10 - 25 mg L-1. Sorption isotherms (7 days equilibrations) were used to calculate from the concentrations the amounts of Si released ( 24 - 38% and 8 - 21%, respectively). Both materials gave about 40 mg L-1 of monosilicic acid-Si plus 30 mg L-1 of disilicic acid-Si when shaken in solution alone (5 g per 125 mL). Straw in dialysis bags ( 0.5 g per 25 mL in 0.1 M NaCl) was shaken in soil suspension ( 5 g per 100 mL) for 60 days. Similar concentrations and releases were measured to those obtained above. About one fifth of the mass of straw was lost by decomposition in the first 15 days. A chloroform treatment prevented decomposition, but Si release was unaffected. Disintegration continued throughout the experiments, with phytoliths being exposed and dissolved. Compared to the rate of release from straw into solution without soil, the release of Si into soil suspensions was increased during the first 20 days by adsorption on the soil, but was then reduced probably through the effect of Fe and Al on the phytolith surfaces. The extent of this blocking effect varied between soils and was not simply related to soil pH.

Quality of medicines stored together in multi-compartment compliance aids

Background and Objective: Dispensing medicines into compliance aids is a common practice in pharmacy contrary to manufacturers’ advice and studies have shown the appearance of light-sensitive tablets is compromised by such storage; we previously found evidence of reduced bioavailability at elevated temperature and humidity. Our objective was to examine the physicochemical stability of two generic atenolol tablets in different compliance aids and with aspirin co-storage at room temperature and at 40 °C/75% relative humidity. Methods: The physicochemical stability of atenolol tablets was evaluated after 28 days of storage and compared with controls by examining visual appearance, weight, disintegration, dissolution, friability and hardness to accepted standards and using a previously validated HPLC method for chemical assay. Results and Discussion: The response to storage was brand-dependent and not straightforward. With one make of atenolol (Alpharma), storage in compliance aids even at room temperature impacted on physical stability, reducing tablet hardness, with storage in Dosett® exerting a greater impact than storage in Medidos® (t-test P < 0·001). Co-storage at elevated temperature and humidity also impacted on the appearance of non-coated aspirin tablets (Angette™). The chemical stability of atenolol was not affected and we did not find evidence of changes to bioavailability with either make. Certainly data for one atenolol make (CP Pharmaceuticals) co-stored with aspirin (Angette™ and Nu-Seals) in both compliance aids at room temperature provided evidence of short-term stability. But medicines are dispensed into compliance aids in multi-factorial ways so our study highlights not only the lack of evidence but also a realization that evidence to support real practice may not be accomplished through research. Conclusion: Reassuring practitioners of the continued stability of medicines in compliance aids under the countless condition in which they are dispensed in practice may requires a different approach involving medical device regulators and more definitive professional guidance.

Pilot study of the short-term physico-chemical stability of atenolol tablets stored in a multi-compartment compliance aid

Study objectives: There is a possibility that lower air, moisture and light protection could impact on physico-chemical stability of medicines inside multi-compartment compliance aids (MCCAs), although this has not yet been proved. The objectives of the study were to examine the physico-chemical stability of atenolol tablets stored in a compliance aid at room temperature, and at elevated temperature and humidity to simulate practice conditions. Methods: Atenolol 100 mg tablets in 28-chamber, plastic compliance aids with transparent lids were stored for four weeks at room temperature and at 40°C with 75% relative humidity. Tablets were also stored at room temperature in original packaging and Petri dishes. Physical tests were conducted to standards as laid down in the British Pharmacopoeia 2005, and dissolution to those of the United States Pharmacopoeia volume 24. Chemical stability was assessed by a validated high-performance liquid chromatography (HPLC) method. Results: Tablets at room temperature in original packaging, in compliance aids and Petri dishes remained the same in appearance and passed physico-chemical tests. Tablets exposed to 40°C with 75% relative humidity in compliance aids passed tests for uniformity of weight, friability and chemical stability but became pale and moist, softer (82 newtons ± 4; p< 0.0001) than tablets in the original packaging (118 newtons ± 6), more friable (0.14% loss of mass) compared with other tablets (0.005%), and failed the tests for disintegration (>15 minutes) and dissolution (only 15% atenolol released at 30 minutes). Conclusion: Although chemical stability was unaffected, storage in compliance aids at 40°C with 75% relative humidity softened atenolol tablets, prolonged disintegration time and hindered dissolution which could significantly reduce bioavailability. This formulation could be suitable for storage in compliance aids at 25°C, but not in hotter, humid weather.

Morphological and molecular characteristics of a new species of Pasteuria parasitic on Meloidogyne ardenensis

A species of the hyper-parasitic bacterium Pasteuria was isolated from the root-knot nematode Meloidogyne ardenensis infecting the roots of ash (Fraxinus excelsior). It is morphologically different from some other Pasteuria pathogens of nematodes in that the spores lack a basal ring on the ventral side of the spore and have a unique clumping nature. Transmission electron microscopy (TEM) showed that the clumps of spores are not random aggregates but result from the disintegration of the suicide cells of the thalli. Sporulation within each vegetative mycelium was shown to be asynchronous. In addition to the novel morphological features 16S rRNA sequence analysis showed this to be a new species of Pasteuria which we have called P. hartismeri. Spores of P. hartismeri attach to juveniles of root-knot nematodes infecting a wide range of plants such as mint (Meloidogyne hapla), rye grass (unidentified Meloidogyne sp.) and potato (Meloidogyne fallax). (c) 2007 Elsevier Inc. All rights reserved.

Radon in homes and risk of lung cancer: collaborative analysis of individual data from 13 European case-control studies

Objective: To determine the risk of lung cancer associated with exposure at home to the radioactive disintegration products of naturally Occurring radon gas. Design: Collaborative analysis of individual data from 13 case-control studies of residential radon and lung cancer. Setting Nine European countries. Subjects 7148 cases Of lung cancer and 14 208 controls. Main outcome measures: Relative risks of lung cancer and radon gas concentrations in homes inhabited during the previous 5-34 years measured in becquerels (radon disintegrations per second) per cubic incite (Bq/m(3)) Of household air. Results: The mean measured radon concentration in homes of people in tire control group was 97 Bq/m(3), with 11% measuring > 200 and 4% measuring > 400 Bq/m(3). For cases of lung cancer the mean concentration was 104 Bq/m(3). The risk of lung cancer increased by 8.4% (95% confidence interval 3.0% to 15.8%) per 100 Bq/m(3) increase in measured radon (P = 0.0007). This corresponds to an increase of 16% (5% to 31%) per 100 Bq/m(3) increase in usual radon-that is, after correction for the dilution caused by random uncertainties in measuring radon concentrations. The dose-response relation seemed to be linear with no threshold and remained significant (P=0.04) in analyses limited to individuals from homes with measured radon < 200 Bq/m(3). The proportionate excess risk did not differ significantly with study, age, sex, or smoking. In the absence of other causes of death, the absolute risks of lung cancer by age 75 years at usual radon concentrations of 0, 100, and 400 Bq/m(3) would be about 0.4%, 0.5%, and 0.7%, respectively, for lifelong non-smokers, and about 25 times greater (10%, 12%, and 16%) for cigarette smokers. Conclusions: Collectively, though not separately, these studies show appreciable hazards from residential radon, particularly for smokers and recent ex-smokers, and indicate that it is responsible for about 2% of all deaths from cancer in Europe.

Microstructure and thermal characteristics of Thai indigenous and broiler chicken muscles

The microstructure and thermal characteristics of Thai indigenous (Gallus domesticus) and broiler chicken (commercial line CP707) biceps femoris and pectoralis muscles were determined. Perimysium thicknesses were 14.2 mum for biceps femoris muscle and 7.10 mum for pectoralis muscle of indigenous chicken muscles, thicker than those of broiler muscles, which were 9.93 mum for biceps femoris muscle and 3.87 mum for pectoralis muscle (P < 0.05). Five endothermic peaks with peak transition temperatures (T-p) of 54.9, 61.7, 65.4, 70.6, and 76.1degreesC were obtained for broiler pectoralis muscle, whereas only 3 endothermic peaks (T-P of 56.6, 62.6, and 74.9degreesC were obtained for broiler biceps femoris muscle. Thai indigenous biceps femoris and pectoralis muscles had endothermic peaks with T-P ranges of 53.5 to 54.8, 60.7 to 61.9, and 75.9 to 76.9degreesC. The fiber diameters of Thai indigenous chicken muscles were greater (P < 0.05) than those of the broiler, 31.7 vs. 20.4 mum for biceps femoris muscle and 28.9 vs. 26.6 pm for pectoralis muscle, respectively. After cooking at 80degreesC for 10 min, the fiber diameter of indigenous chicken muscles significantly decreased while those of the broiler significantly increased. The mean of sarcomere lengths of the raw muscles ranged from 1.56 to 1.64 mun and decreased to 0.92 to 1.32 mum (P < 0.001) for broiler muscles and 1.22 to 1.35 mum (P < 0.001) for indigenous chicken muscles after cooking. The perimysium and endomysium of broiler muscles melted after cooking at 80degreesC, however, only slight disintegration was observed in these tissues in the indigenous chicken muscles.

Miscibility studies of the blends of chitosan with some cellulose ethers

The polymeric films have been prepared based on blends of chitosan with two cellulose ethers-hydroxypropylmethylcellulose and methylcellulose by casting from acetic acid solutions. The films were transparent and brittle in a dry state but an immersion of the samples in deionized water for over 24 h leads to their disintegration or partial dissolution. The miscibility of the polymers in the blends has been assessed by infrared spectroscopy, wide-angle X-ray diffraction, scanning electron microscopy and thermal gravimetric analysis. It was shown that although weak hydrogen bonding exists between the polymer functional groups the blends are not fully miscible in a dry state. (c) 2005 Elsevier Ltd. All rights reserved.

The engagement of territorial knowledge communities with European spatial planning and the territorial cohesion debate: a Baltic perspective

Recent, dramatic spatial development trends have contributed to the consolidation of a unique territorial governance landscape in the Baltic States. The paper examines the transformation of this evolving institutional landscape for planning practice and knowledge, which has been marked by the disintegration of Soviet institutions and networks, the transition to a market-based economy and the process of accession to the EU. It explores the evolution of territorial knowledge channels in the Baltic States, and the extent and nature of the engagement of actors' communities with the main knowledge arenas and resources of European spatial planning (ESP). The paper concludes that recent shifts in the evolution of these channels suggest the engagement of ESP has concentrated among epistemic communities at State and trans-national levels of territorial governance. The limited policy coordination across a broader spectrum of diverse actors is compounded by institutionally weak and fragmented professional communities of practice, fragmented government structures and marginalized advocacy coalitions.

Exploring identities and cultures in inter-professional education and collaborative professional practice

Although the concept of multi-agency working has been pursued and adopted as the most appropriate way to improve child care provision and health workforces in recent years, both in the UK and more globally, research suggests that participation in such work can be problematic. This article examines current developments in inter-professional education and collaborative professional practice. Drawing on desk research across the fields of Education, Health and Social Care, it applies a critical lens to re-examine inter-professional working using well-established concepts of profession, identity, culture, career, and training/work transitions. The article uses theoretical hooks to look for similarities and differences in the promotion of inter-professionality across the Education, Health and Social Care sectors, alongside those which occur within each. It looks towards a re-invigoration of knowledge creation and application through research. This is viewed as especially urgent in times of fragmentation, transformation, and arguably, disintegration, in the services its professional and academic educators and workers seek to serve.

[Global climate] global aerosols [in state of the climate in 2008]

The global mean temperature in 2008 was slightly cooler than that in 2007; however, it still ranks within the 10 warmest years on record. Annual mean temperatures were generally well above average in South America, northern and southern Africa, Iceland, Europe, Russia, South Asia, and Australia. In contrast, an exceptional cold outbreak occurred during January across Eurasia and over southern European Russia and southern western Siberia. There has been a general increase in land-surface temperatures and in permafrost temperatures during the last several decades throughout the Arctic region, including increases of 1° to 2°C in the last 30 to 35 years in Russia. Record setting warm summer (JJA) air temperatures were observed throughout Greenland. The year 2008 was also characterized by heavy precipitation in a number of regions of northern South America, Africa, and South Asia. In contrast, a prolonged and intense drought occurred during most of 2008 in northern Argentina, Paraguay, Uruguay, and southern Brazil, causing severe impacts to agriculture and affecting many communities. The year began with a strong La Niña episode that ended in June. Eastward surface current anomalies in the tropical Pacific Ocean in early 2008 played a major role in adjusting the basin from strong La Niña conditions to ENSO-neutral conditions by July–August, followed by a return to La Niña conditions late in December. The La Niña conditions resulted in far-reaching anomalies such as a cooling in the central tropical Pacific, Arctic Ocean, and the regions extending from the Gulf of Alaska to the west coast of North America; changes in the sea surface salinity and heat content anomalies in the tropics; and total column water vapor, cloud cover, tropospheric temperature, and precipitation patterns typical of a La Niña. Anomalously salty ocean surface salinity values in climatologically drier locations and anomalously fresh values in rainier locations observed in recent years generally persisted in 2008, suggesting an increase in the hydrological cycle. The 2008 Atlantic hurricane season was the 14th busiest on record and the only season ever recorded with major hurricanes each month from July through November. Conversely, activity in the northwest Pacific was considerably below normal during 2008. While activity in the north Indian Ocean was only slightly above average, the season was punctuated by Cyclone Nargis, which killed over 145,000 people; in addition, it was the seventh-strongest cyclone ever in the basin and the most devastating to hit Asia since 1991. Greenhouse gas concentrations continued to rise, increasing by more than expected based on with CO2 the 1979 to 2007 trend. In the oceans, the global mean uptake for 2007 is estimated to be 1.67 Pg-C, about CO2 0.07 Pg-C lower than the long-term average, making it the third-largest anomaly determined with this method since 1983, with the largest uptake of carbon over the past decade coming from the eastern Indian Ocean. Global phytoplankton chlorophyll concentrations were slightly elevated in 2008 relative to 2007, but regional changes were substantial (ranging to about 50%) and followed long-term patterns of net decreases in chlorophyll with increasing sea surface temperature. Ozone-depleting gas concentrations continued to fall globally to about 4% below the peak levels of the 2000–02 period. Total column ozone concentrations remain well below pre-1980, levels and the 2008 ozone hole was unusually large (sixth worst on record) and persistent, with low ozone values extending into the late December period. In fact the polar vortex in 2008 persisted longer than for any previous year since 1979. Northern Hemisphere snow cover extent for the year was well below average due in large part to the record-low ice extent in March and despite the record-maximum coverage in January and the shortest snow cover duration on record (which started in 1966) in the North American Arctic. Limited preliminary data imply that in 2008 glaciers continued to lose mass, and full data for 2007 show it was the 17th consecutive year of loss. The northern region of Greenland and adjacent areas of Arctic Canada experienced a particularly intense melt season, even though there was an abnormally cold winter across Greenland's southern half. One of the most dramatic signals of the general warming trend was the continued significant reduction in the extent of the summer sea-ice cover and, importantly, the decrease in the amount of relatively older, thicker ice. The extent of the 2008 summer sea-ice cover was the second-lowest value of the satellite record (which started in 1979) and 36% below the 1979–2000 average. Significant losses in the mass of ice sheets and the area of ice shelves continued, with several fjords on the northern coast of Ellesmere Island being ice free for the first time in 3,000–5,500 years. In Antarctica, the positive phase of the SAM led to record-high total sea ice extent for much of early 2008 through enhanced equatorward Ekman transport. With colder continental temperatures at this time, the 2007–08 austral summer snowmelt season was dramatically weakened, making it the second shortest melt season since 1978 (when the record began). There was strong warming and increased precipitation along the Antarctic Peninsula and west Antarctica in 2008, and also pockets of warming along coastal east Antarctica, in concert with continued declines in sea-ice concentration in the Amundsen/Bellingshausen Seas. One significant event indicative of this warming was the disintegration and retreat of the Wilkins Ice Shelf in the southwest peninsula area of Antarctica.

Controlling market power of vertically integrated firms in electricity networks: demand response of aggregator agents

This article reports the results of an experiment that examined how demand aggregators can discipline vertically-integrated firms - generator and distributor-retailer holdings-, which have a high share in wholesale electricity market with uniform price double auction (UPDA). We initially develop a treatment where holding members redistribute the profit based on the imposition of supra-competitive prices, in equal proportions (50%-50%). Subsequently, we introduce a vertical disintegration (unbundling) treatment with holding-s information sharing, where profits are distributed according to market outcomes. Finally, a third treatment is performed to introduce two active demand aggregators, with flexible interruptible loads in real time. We found that the introduction of responsive demand aggregators neutralizes the power market and increases market efficiency, even beyond what is achieved through vertical disintegration.

Enteric coated spheres produced by extrusion/spheronization provide effective gastric protection and efficient release of live therapeutic bacteria

We present a novel but simple enteric coated sphere formulation containing probiotic bacteria (Lactobacillus casei). Oral delivery of live bacterial cells (LBC) requires live cells to survive firstly manufacturing processes and secondly GI microbicidal defenses including gastric acid. We incorporated live L. casei directly in the granulation liquid, followed by granulation, extrusion, spheronization, drying and spray coating to produce dried live probiotic spheres. A blend of MCC, calcium-crosslinked alginate, and lactose was developed that gave improved live cell survival during manufacturing, and gave excellent protection from gastric acid plus rapid release in intestinal conditions. No significant loss of viability was observed in all steps except drying, which resulted in approximately 1 log loss of viable cells. Eudragit coating was used to protect dried live cells from acid, and microcrystalline cellulose (MCC) was combined with sodium alginate to achieve efficient sphere disintegration leading to rapid and complete bacterial cell release in intestinal conditions. Viability and release of L. casei was evaluated in vitro in simulated GI conditions. Uncoated spheres gave partial acid protection, but enteric coated spheres effectively protected dried probiotic LBC from acid for 2 h, and subsequently released all viable cells within 1h of transfer into simulated intestinal fluid.