bluuebunny/crossref_metadata_2025_split huggingface dataset:
Life detection experiments of the Viking Mission on Mars can be best interpreted with a Fenton oxidation reaction composed of H2O2 and Fe2+ and iron-catalysed decomposition of H2O2
Authors: Apak Resat 
Published: May 2008

AbstractThe findings of the life detection experiments carried out during the Viking mission to Mars were reinterpreted with a chemical hypothesis. The labelled release (LR), pyrolytic release (PR) and gas exchange (GEx) experiments were interpreted with Fenton chemistry. Oxygen and carbon dioxide evolution from Martian soil upon wetting and nutrient addition could be attributed to competition reactions between the Fenton-type oxidation of organic nutrients with the aqueous (hydrogen peroxide+Fe(II)) combination and the iron-catalysed decomposition of hydrogen peroxide. A substantial evolution of radioactive gas upon addition of labelled organic nutrient solution to soil, whereas the ceasing of this gas with a heat treated sample in the LR experiments, was attributed to Fenton oxidation and hydrogen peroxide thermal decomposition, respectively. The peculiar kinetics of LR and PR experiments – that cannot be fully explained by other chemical or biochemical scenarios – were easily explained with this new hypothesis, i.e. limitation of the Fenton reaction may arise from the depletion of reactants, the build-up of ferric hydroxide on soil and excessive scavenging by the organic nutrients of the generated hydroxyl radicals. Reabsorption or adsorption of evolved or introduced CO2 may involve the formation of carbonate compounds (e.g., magnesium carbonate and bicarbonate) on the surface of alkalinized soil as a result of the Fenton reaction.A critical evaluation of the recent biological hypothesis assuming the utilization of a hydrogen peroxide–water intracellular fluid by putative organisms (Houtkooper & Schulze-Makuch 2007) is also made.
Benefits and barriers to perennial forage crops in Iowa corn and soybean rotations
Authors: Olmstead Julia , Brummer E. Charles 
Published: May 2008

AbstractThe transition away from forage-based cropping systems in Iowa to corn and soybean rotations since World War II has corresponded with degraded economic and environmental conditions in the state. Falling net incomes for farmers and concern over global warming and the effects of agriculture-related pollution on water, wildlife and human health have increased interest in diversified cropping systems. This paper reviews the benefits of diversifying Iowa corn and soybean rotations with perennial forage species such as alfalfa and red clover. Perennial forage crops improve soil quality, decrease NO3-N leaching and soil erosion, increase carbon sequestration and decrease pesticide and herbicide needs by controlling weed and insect pests. Forage legumes reduce N fertilizer needs for succeeding corn crops at a higher rate than soybeans, and corn crops following forages have higher yields than after corn or soybeans. Farmers who add alfalfa to corn and soybean rotations could realize significant economic gains. A simulated 5-year rotation in Iowa including corn–soybeans–oats/alfalfa–alfalfa–alfalfa would result in a 24% net income increase over 5 years of corn–soybean–corn–soybean–corn, even with government farm support payments for the row crops. Farm policies that encourage commodity production create little incentive for Iowa farmers to diversify their cropping systems beyond corn and soybeans, despite the clear economic and ecological benefits. We recommend increasing federal support for conservation programs that reward environmentally beneficial farm practices such as the Conservation Securities Program and we encourage land grant universities to hire researchers interested in alternative agricultural systems.
Weed management in organic echinacea (Echinacea purpurea) and lettuce (Lactuca sativa) production
Authors: Kristiansen P. , Sindel B.M. , Jessop R.S. 
Published: May 2008

AbstractWeed management is a major constraint in organic production. It can be expensive and time-consuming and severe crop yield losses may be incurred when weeds are not adequately controlled. Research on organic weed management (OWM) in herb and vegetable production is increasing internationally, although in Australia very little work has been done to assess current OWM knowledge among growers, and to test the efficacy and cost effectiveness of the weed management practices used by organic growers. The effect of hand weeding, tillage, hay mulch, pelletized paper mulch (PP) and an unweeded control treatment on weed growth, crop growth and cost effectiveness were evaluated in several field trials on the Northern Tablelands of New South Wales using lettuce (Lactuca sativaL.) and echinacea (Echinacea purpureaMoench. [L.]). In echinacea, hand weeding, hay mulch and PP reduced weed growth by at least 90% compared with the control, while tillage reduced weed levels by about 50%. The more expensive weeding methods such as hand weeding and hay mulch (AU$9600 and 8900 ha−1respectively) produced higher yields, while the cheaper methods such as tillage ($4000 ha−1) had low crop yields and were therefore 25–50% less cost effective. In lettuce, weed growth was reduced by 96% for hand weeding and PP compared with the control, 85% for hay mulch and 66% for tillage. Weed management was cost-effectively achieved using cheaper weeding methods such as tillage ($985 ha−1) compared with more expensive methods such as hand weeding and hay mulching ($4400 and 7600 ha−1respectively). PP had lower yields and was expensive ($12,500 ha−1) and was usually not cost effective in these trials. The results highlight several important advantages and disadvantages of currently used OWM methods in the field.
The adaptive consumer: shifting attitudes, behavior change and CSA membership renewal
Authors: Russell Willow Saranna , Zepeda Lydia 
Published: May 2008

AbstractA qualitative study was conducted with a subset of a Community Supported Agriculture (CSA) membership base in Wisconsin, USA to examine attitude and behavior change associated with membership. Changes that were examined included: modified eating or cooking habits, increased consideration of food seasonality and associated consumer preferences for seasonal products, and an enhanced appreciation for farming. Although this study investigated ‘spillover’ attitude or behavior changes (e.g. reduced driving or increased use of environmentally friendly cleaning products), none were observed. This study indicates that attitude and behavior changes are generated by the structural elements of CSA including exposure to the farm, interactions with the farmer, and the constraints imposed by a pre-selected bundle of vegetables. There was no indication that changes occur due to the development and enforcement of social norms within the CSA membership base. Community, in the context of this CSA, is expressed primarily as a conceptual community of interest. Our results suggest that demonstrated attitude and behavior change increases the likelihood that a consumer will renew their CSA membership.
Introduction of floating gardening in the north-eastern wetlands of Bangladesh for nutritional security and sustainable livelihood
Authors: Irfanullah Haseeb Md. , Adrika Ahana , Ghani Abdul , Khan Zakir Ahmed , Rashid Md. Abdur 
Published: May 2008

AbstractFloating gardening is a form of hydroponics or soil-less culture. It is an age-old practice of crop cultivation in the floodplains of southern Bangladesh, where aquatic plants such as water hyacinth (Eichhornia crassipes) are used to construct floating platforms on which seedlings are raised and vegetables and other crops cultivated in the rainy season. The platform residue is used in the preparation of beds for winter vegetable gardening. Floating gardening was introduced in 2006 on a pilot-scale in the north-east wetlands of the country, as a contribution to food security and as a supplementary income for the marginalized community. The overall experience of floating cultivation in three selected villages was encouraging. Local people became aware of this new farming system and their level of knowledge improved. Communities were mobilized into groups to make floating platforms, and platform residues were later used to establish winter gardens. Cultivation was successful on both types of plot, and vegetables were both consumed by the producers and sold in the market. The input–output analysis revealed floating gardening to be a feasible alternative livelihood option for the wetland dwellers. The method provided targeted landless people with parcels of land in the monsoon, enabling them to grow vegetables. Floating gardening and associated winter gardening appear to have the potential for introduction to other parts of the world where aquatic weed management is a major problem.
Maize silage as an energy supplement in organic dairy cow rations
Authors: Velik Margit , Baumung Roswitha , Knaus Wilhelm F. 
Published: May 2008

AbstractThe literature implicates strongly that including energy supplements in dairy rations based on protein-rich forages increases performance and feed efficiency due to an improved and more balanced ruminal energy and protein supply. Therefore, both conventional and organic dairy farms primarily supplement roughages with concentrates, containing high proportions of cereal grains. However, considering the main principles of sustainable agricultural systems and nutrient cycles, the question of alternatives is raised. Therefore, the present study was conducted to compare grain and maize silage as energy sources in organic dairy cow rations. Two grass–clover silage-based diets, offered on anad libitumbasis, were supplemented either with 1 kg grain mixture plus 0.5 kg hay (treatment group G) or 2.1 kg maize silage (treatment group M) on a dry matter (DM) basis. The trial was carried out as a change-over design and lasted for 15 weeks. Intake of concentrates, DM and utilizable crude protein in the duodenum (uCP) were similar in both treatments. However, significant differences between treatments G and M were found for grass–clover silage dry matter intake (DMI) (13.4 versus 12.9 kg), forage DMI (14.6 versus 15.7 kg), crude protein (CP) intake (2885 versus 2801 g), ruminal nitrogen balance (RNB) (40 versus 29 g) and intake of neutral detergent fiber (NDF) (7630 versus 7900 g). Milk yield was not affected by treatment, but in treatment M, milk fat content was at 42.4 g kg−1, significantly higher, and milk urea concentration at 19.7 mg 100 ml−1, significantly lower, as compared with treatment G. Efficiency of N use (N in milk in % of N intake) tended to be improved in treatment M. Balances of energy and uCP (intake as a percentage of requirements) were unaffected by treatment.
The barriers to further adoption of organic farming and genetic engineering in Australia: views of agricultural professionals and their information sources
Authors: Wheeler Sarah Ann 
Published: May 2008

AbstractResearch has shown that agricultural professionals are one of the major influences on farmer adoption of agricultural innovations. Genetic engineering and organic farming represent two vastly different innovations in agriculture, and both assert to have important sustainability outcomes. This paper presents the views from a telephone survey of agricultural scientists, extension officers and academics in Australia (n=185) on the barriers to further adoption of organic farming and agricultural genetic engineering, as well as exploring where they obtain their information about the two innovations. Many professionals believe that market issues (in terms of small market size and the extent that consumers are willing to pay premiums) will limit the size of farmer adoption of organics in Australia, while on-farm issues (in terms of production difficulties and pest and disease problems) are named as the second largest barrier to further adoption. On the other hand, professionals from the targeted sample, who were more knowledgeable about organic farming, named information needs and lack of government support as the major barrier facing further diffusion of organic farming. In contrast, public attitudes and negative media portrayal are named as the largest barrier facing further adoption of genetic engineering in Australia. The uncertainty surrounding the research into genetic engineering (and the lack of long-term research) is believed to be the second largest barrier facing further diffusion of genetic engineering while market problems are seen as the third largest barrier.
Soil CO2 respiration: Comparison of chemical titration, CO2 IRGA analysis and the Solvita gel system
Authors: Haney R.L. , Brinton W.F. , Evans E. 
Published: May 2008

AbstractThe measurement of soil carbon dioxide respiration is a means to gauge biological soil fertility. Test methods for respiration employed in the laboratory vary somewhat, and to date the equipment and labor required have somewhat limited more widespread adoption of such methodologies. The purpose of this research is to compare the results of measured soil CO2 respiration using three methods: (1) titration method; (2) infrared gas analysis (IRGA); and (3) the Solvita gel system for soil CO2 analysis. We acquired 36 soil samples from across the USA for comparison, which ranged in pH from 4.5 to 8.5, organic C from 0.8 to 4.6% and the clay content from 6 to 62%. All three methods were highly correlated with each other after 24-h of incubation (titration and Solvita r2=0.82, respirometer and Solvita r2=0.79 and titration versus respirometer r2=0.95). The 24-h (1-day) CO2 release from all three methods was also highly correlated to both basal soil respiration (7–28 days) and cumulative 28-day CO2 respiration. An additional 24 soil samples were acquired and added to the original 36, for a total of 60 soil samples. These samples were used for calibration of the Solvita gel digital color reader results using CO2-titration results and regression analysis. Regression analysis resulted in the equation y=20.6∗(Solvita number)−16.5 with an r2 of 0.83. The data suggest that the Solvita gel system for soil CO2 analysis could be a simple and easily used method to quantify soil microbial activity. Applications may also exist for the gel system for in situ measurements in surface gas chambers. Once standardized soil sampling and laboratory analysis protocols are established, the Solvita method could be easily adapted to commercial soil testing labs as an index of soil microbial activity.
A Brief History of the End of Time
Authors: Seitz Russell 
Published: May 2008

We face the end of an era of abundance. The world is running out of geological time. A generation ago, every person on the face of the Earth had a year of time on deposit in the geological column— 4.5 billion years of deep time for 4.5 billion people.No longer! Earth's population has been growing faster than time has been passing, and with 6.5 billion people afoot, the average person's share of the geological column has shrunk to 252 days. At this rate of population growth, the supply of unexplored strata may melt away before the glaciers disappear, threatening a mass extinction of Earth scientists. Dividing the geological column equitably among the geoscientists alive today would allow each scarcely a millennium's worth of strata as the focus of their life's work, yet most commence their careers with thesis titles that lay claim to whole periods and epochs—a million‐to‐one disparity between supply and demand.
Tsunami and Its Hazards in the Indian and Pacific Oceans
Authors: Bilek Susan L. 
Published: May 2008

The 26 December 2004 earthquake and tsunami that struck offshore the Sumatra‐Andaman islands with tragic effects on inhabitants around the Indian Ocean is obviously a key event in the Earth sciences. Much like other critical topics of recent years, such as environmental issues and climate change, the earthquake and tsunami affected our science in many ways, while also connecting our science with the public policy arena.Our previous understanding of these enormous earthquakes and their resulting tsunamis had been limited to two previous magnitude 9+ events, the Chile and Alaska earthquakes of the 1960s. At that time, digital recording of global seismic data was not standard practice, and other data sets were equally limited.
Glucagon is absorbed from the rectum but does not hasten recovery from hypoglycaemia in patients with type 1 diabetes
Authors: Parker David R. , Braatvedt Geoffrey D. , Bargiota Alexandra , Newrick Paul G. , Brown Stephen , Gamble Gregory , Corrall Roger J. M. 
Published: May 2008

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Patients with type 1 diabetes experience recurrent hypoglycaemia and have abnormal glucose counter regulatory responses with a failure to secrete glucagon. It is unknown if rectal glucagon is absorbed and what effect this may have on counter regulation from hypoglycaemia. WHAT THIS STUDY ADDS • A rectal suppository of glucagon results in a rise in plasma glucagon with metabolic effects in normal subjects. Similarly rectal glucagon results in a rise in plasma glucagon in patients with type 1 diabetes, but 1 mg does not improve recovery rates from experimental hypoglycaemia when compared with placebo.• Larger doses of glucagon per rectum may provide pharmacological circulating concentrations with resulting therapeutic benefit during recovery from hypoglycaemia and deserves further study.AIMSA failure to secrete glucagon during hypoglycaemia is near universal in patients with type 1 diabetes 5 years after disease onset and may contribute to delayed counter‐regulation during hypoglycaemia. Rectal glucagon delivery may assist glucose recovery following insulin‐induced hypoglycaemia in such patients and has not been previously studied.METHODSSix male patients (age 21–38 years) with type 1 diabetes (median duration 10 years) without microvascular complications, were studied supine after an overnight fast on two separate occasions at least 14 days apart. After omission of their usual morning insulin and 45 min rest, hypoglycaemia was induced by an intravenous insulin infusion which was terminated when capillary glucose concentration reached 2.5 mmol l−1. Subjects were randomized to insert a rectal suppository containing 100 mg indomethacin alone (placebo) or 100 mg indomethacin plus 1 mg glucagon at the hypoglycaemic reaction. Serial measurements were made for 120 min.RESULTSIn the two groups, mean (SD) plasma glucose concentrations fell to a similar nadir of 1.8 (0.7) mmol l−1 (placebo) and 2.1 (1.2) mmol l−1 (glucagon). Peak plasma glucagon following hypoglycaemia was higher in the glucagon group; 176 (32) ng l−1vs. 99 (22) ng l−1 after placebo (P = 0.006). However, the glucose recovery rate over 120 min after hypoglycaemia did not differ significantly.CONCLUSIONSOur results provide evidence for the absorption of glucagon from the rectum. They also indicate that 1 mg does not constitute a useful mode of therapy to hasten recovery from hypoglycaemia in patients with type 1 diabetes.
A signal of increased risk of hypoglycaemia with angiotensin receptor blockers caused by confounding
Authors: Grégoire Fleur , Pariente Antoine , Fourrier‐Reglat Annie , Haramburu Françoise , Bégaud Bernard , Moore Nicholas 
Published: May 2008

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Spontaneous reporting is a valuable way to provide early detection for safety signals related to drug use.• Due to the increasing size of pharmacovigilance databases, data‐mining and other automated methods for signal generation are more and more often used.• Even if these methods are very useful, they do not allow, for every particular association, an automated exploration of the multiple sources of confounding. WHAT THIS STUDY ADDS • An association between angiotensin receptor blockers use and hypoglycaemia was found in the French pharmacovigilance database.• This signal disappeared after stratification on antidiabetic drug use, suggesting confounding by indication.• The association between hypoglycaemia and angiotensin receptor blocker use was actually less than expected in concomitant antidiabetic drug users.AIMSTo study reporting of hypoglycaemia in angiotensin receptor blocker (ARB) users, and to investigate the possibility of confounding.METHODSThe French pharmacovigilance database was examined for an association between hypoglycaemia and ARBs or other drugs using reports notified between 1996 and 2005. This association was also tested in patients taking or not taking antidiabetic agents (ADAs) using reporting odds ratios (ROR).RESULTSHypoglycaemia was mentioned in 807 of the 174 595 reports entered during the study period. Overall hypoglycaemia was associated with the use of ARBs [ROR 2, 95% confidence interval (CI) 1, 3] and with the use of ADAs (ROR 32, 95% CI 27, 37). Moreover, the use of ARBs was associated with the use of ADAs (OR 7, 95% CI 6, 8). Considering separately reports with and without ADA, the association of ARB use with a higher risk of hypoglycaemia disappeared (OR 0.4, 95% CI 0.2, 0.8 and OR 2, 95% CI 1, 3, respectively).CONCLUSIONA signal indicating an association between ARB use and hypoglycaemia was found in the French pharmacovigilance database. This signal disappeared after stratification on ADA use, thus suggesting confounding by indication. Moreover, the association between ARB use and hypoglycaemia was negative in ADA users.
The reproducibility of adenosine monophosphate bronchial challenges in mild, steroid‐naive asthmatics
Authors: Singh Dave , Fairwood Jennifer , Murdoch Robert , Weeks Amanda , Russell Paul , Roy Kay , Langley Steve , Woodcock Ashley 
Published: May 2008

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Repeated adenosine monophosphate (AMP) challenges are used to assess drug effects in asthma clinical trials, but may be prone to tachyphylaxis when repeated at short intervals.• Possible tachyphylaxis at 12‐ and 24‐h intervals has not been studied. WHAT THIS STUDY ADDS • Clinically relevant tachyphylaxis after repeated AMP challenges does not occur when repeated at 12‐ and 24‐h intervals.• AMP challenges at these intervals can be used to assess drug effects in clinical trials.AIMSRepeated adenosine monophosphate (AMP) challenges are used to assess drug efficacy in clinical trials of mild, steroid‐naive asthmatics. Refractoriness has been reported after repeated challenges over short intervals. This study evaluated possible tachyphylaxis after repeated AMP challenges at 12 and 24 h in mild, steroid‐naive asthmatics.METHODSThis was an open, three‐way crossover study. Twenty‐six steroid‐naive asthmatic subjects were randomized to the following AMP challenge regimens separated by 7–14 days: (A) challenge at 08.00 h, repeated 24 h later; (B) challenge at 08.00 h, repeated 12 and 24 h later; (C) challenge at 20.00 h, repeated 12 h later. Comparisons within day were assessed using 90% confidence intervals (CIs). Non‐inferiority approach taken with 1 doubling concentration (DC) as a clinically relevant difference.RESULTSRegimen A: Significant increase in AMP reactivity at 24 h. Mean DC difference was 0.6 (90% CI 0.24, 0.96). Regimen B: No evidence of difference between AMP reactivity at 08.00 h and a repeated challenge 12 h later. Repeated challenge at 24 h caused a significant increase in provocation concentration (PC)20 compared with 12 h (mean DC difference 0.48, 90% CI 0.02, 0.95) and 0 h (mean DC difference 0.82, 90% CI 0.49, 1.14 – the upper CI exceeds the criteria of 1 DC). Challenge regimen C: No difference between challenges; mean DC difference of 0.28 (90% CI −0.2, 0.76).CONCLUSIONThe small decline in AMP reactivity during repeated challenges was not consistently observed, and was small compared with the known effects of inhaled drugs.