Monitoring and modeling temperature variations inside silage stacks using novel wireless sensor networks     

Ole Green  Esmaeil S. Nadimi  Victoria Blanes-Vidal  Rasmus N. Jrgensen  Ida M.L. Drejer Storm  Claus G. Srensen 《Computers and Electronics in Agriculture》2009,69(2):149-157

By monitoring silage temperature at different locations inside silage stacks, it is possible to detect any significant increases in temperature occurring during silage decomposition. The objectives of this study were: (1) to develop novel noninvasive wireless sensor nodes for measuring the temperature inside silage stacks; (2) to design a suitable sensor protection housing that prevents physical and chemical damage to the sensor; and (3) to mathematically model temperature variations inside a silage stack, using system identification techniques. The designed wireless nodes were used to monitor temperatures in a full-sized silage stack over 53 days. Results showed that the wireless sensor nodes accurately monitored the temperature inside the silage stack at depths of 25 and 50 cm and reliably transmitted the measured data through the network; between 98.9% and 99.4% of the packets disseminated from the sensor nodes were successfully delivered to the gateway. The reliable performance of the network confirmed the correct choice of network characteristics (i.e., frequency range of 433 MHz, a handshaking communication protocol, and 10 mW transmission power). The designed sensor housings were capable of withstanding the high loads that occurred during ensiling, storage, and feed-out. Mathematical models estimating the relations between the silage temperatures (at depths of 25 and 50 cm) and air and soil temperatures were obtained. Black-box modeling using the prediction error method (PEM) was selected as the identification method. Among different black-box models such as ARX, ARMAX, output-error (OE), and Box–Jenkins (BJ), with different model orders, a third-order Box–Jenkins model structure gave the best performance in terms of prediction accuracy. The success rate of the models proposed for silage temperature prediction ranged between 90.0% and 94.3%. Furthermore, there was no significant autocorrelation remaining in the residuals. The results of this study indicate that the designed wireless sensor nodes could potentially be used for detecting silage decomposition processes and improving the efficacy of silage conservation systems.  相似文献   

Development of pollution-induced community tolerance is linked to structural and functional resilience of a soil bacterial community following a five-year field exposure to copper     

Kristian K. Brandt  Rasmus J.N. Frandsen  Ole Nybroe 《Soil biology & biochemistry》2010,42(5):748-757

Copper (Cu) is accumulating in agricultural soils worldwide creating concern for adverse impacts on soil microbial communities and associated ecosystem services. In order to evaluate the structural and functional resilience of soil microbial communities to increasing Cu levels, we compared a Cu-adapted and a corresponding non-adapted soil microbial community for their abilities to resist experimental Cu pollution. Laboratory soil microcosms were set-up with either High-Cu soil from Cu-amended field plots (63 g Cu m⁻²) or with Low-Cu control soil from the same five-year field experiment. Laboratory treatments consisted of Cu amendments in the presence or absence of pig manure. Microbial activities (soil respiration, substrate-induced respiration, [³H]leucine incorporation), bacterial community structure (terminal restriction fragment length polymorphism, T-RFLP), community-level physiological profiles, and pollution-induced bacterial community tolerance (PICT detected using the [³H]leucine incorporation technique) were monitored for 12 weeks. The High-Cu and Low-Cu soil microbial communities initially exhibited almost identical structure and function and could only be distinguished from each other by their differential Cu tolerance. Experimental Cu pollution inhibited microbial activities, affected bacterial community structure, and induced further bacterial community tolerance to Cu. However, Low-Cu and High-Cu soil microbial communities showed essentially identical responses. Manure amendment did not protect against Cu toxicity and slightly increased Cu bioavailability as measured by a Cu-specific whole-cell bacterial biosensor. Our results indicate convergence of bacterial community structure and function in the High-Cu and Low-Cu soils during the five-year field experiment. We conclude that soil bacterial communities can exhibit structural and functional resilience to a five-year Cu exposure by virtue of their ability to develop Cu tolerance without affecting overall community structure. The observed increased Cu tolerance may involve phenotypic adaptation or selection at the micro-diversity level, for example an increased proportion of Cu-resistant strains within each bacterial species, which go undetected by T-RFLP community fingerprinting. Finally, our results indicate that Cu-dissolved organic matter complexes contribute to microbial toxicity in manure-amended soils implying that free Cu may comprise a poor predictor of metal toxicity.  相似文献   

Genetic population structure and variation at phenology-related loci in anadromous Arctic char (Salvelinus alpinus)     

Rikke P. A. Madsen  Magnus W. Jacobsen  Kathleen G. O'Malley  Rasmus Nygaard  Kim Præbel  Bjarni Jónsson  Jose M. Pujolar  Dylan J. Fraser  Louis Bernatchez  Michael M. Hansen 《Ecology of Freshwater Fish》2020,29(1):170-183

The Arctic will be especially affected by climate change, resulting in altered seasonal timing. Anadromous Arctic char (Salvelinus alpinus) is strongly influenced by sea surface temperature (SST) delimiting time periods available for foraging in the sea. Recent studies of salmonid species have shown variation at phenology-related loci associated with timing of migration and spawning. We contrasted genetic population structure at 53 SNPs versus four phenology-related loci among 15 anadromous Arctic char populations from Western Greenland and three outgroup populations. Among anadromous populations, the time period available for foraging at sea (>2°C) ranges from a few weeks to several months, motivating two research questions: (a) Is population structure compatible with possibilities for evolutionary rescue of anadromous populations during climate change? (b) Does selection associated with latitude or SST regimes act on phenology-related loci? In Western Greenland, strong isolation by distance at SNPs was observed and spatial autocorrelation analysis showed genetic patch size up to 450 km, documenting contingency and gene flow among populations. Outlier tests provided no evidence for selection at phenology-related loci. However, in Western Greenland, mean allele length at OtsClock1b was positively associated with the time of year when SST first exceeded 2°C and negatively associated with duration of the period where SST exceeded 2°C. This is consistent with local adaptation for making full use of the time period available for foraging in the sea. Current adaptation may become maladaptive under climate change, but long-distance connectivity of anadromous populations could redistribute adaptive variation across populations and lead to evolutionary rescue.  相似文献   

Vertebral scale system to measure heart size in growing puppies.     

M M Sleeper  J W Buchanan 《Journal of the American Veterinary Medical Association》2001,219(1):57-59

OBJECTIVE: To determine relative heart size in clinically normal puppies and assess whether relative heart size changes with growth. DESIGN: Prospective radiographic study. ANIMALS: 11 puppies without evidence of disease. PROCEDURE: Standardized measurements of the long and short axes of the heart, midthoracic vertebrae, and other structures were made at 3, 6, 12, and 36 months of age. Measurements were recorded in millimeters and number of thoracic vertebral lengths spanned by each dimension, measured caudally from T4 on lateral radiographic views. The long and short axis measurements of the heart, expressed in vertebral lengths, were added to yield vertebral heart size. RESULTS: Mean +/- SD vertebral heart sizes on lateral radiographic views at 3, 6, 12, and 36 months of age were 10.0 +/- 0.5, 9.8 +/- 0.4, 9.9 +/- 0.6, and 10.3 +/- 0.6 vertebrae, respectively. Significant differences were not detected. CONCLUSIONS AND CLINICAL RELEVANCE: Vertebral heart size measurements in puppies are within the reference range for adult dogs (9.7 +/- 0.5 vertebrae) and do not change significantly with growth to 3 years of age. Standards for determining cardiac enlargement are similar in puppies and adult dogs.  相似文献   

OYSTERS: A REVIEW OF IGNORANCE     

Buchanan GC 《Science (New York, N.Y.)》1897,6(134):137-138

  相似文献   

Salinity risk assessment using fuzzy multiple criteria evaluation          下载免费PDF全文

S. Buchanan  J. Huang  J. Triantafilis 《Soil Use and Management》2017,33(2):216-232

For agricultural productivity, primary salinity constitutes a hazard. Understanding the risk of secondary salinization is also important and it is necessary to map all these hazards and the overall risk. One approach is digital soil mapping. We have developed hazard maps of root zone (0–2 m) and subsurface (6–12 m) salinity, as well as groundwater height, using empirical best linear unbiased prediction using proximal and remotely sensed ancillary data. To convert the hazards into salinity risk maps and account for some uncertainty, fuzzy membership functions (FMF) were used in conjunction with semantic import models that consider the vulnerability of agricultural crops. Therefore, we developed memberships (μ) to three salinity risk classes and created maps of each, including root zone (μ_RSR) and subsurface (μ_SSR) salinity, and depth to groundwater (μ_GTR). To estimate groundwater (μ_GSR) and overall salinity risk (μ_OSR), fuzzy multiple criteria evaluation was undertaken. To account for μ_GSR, the μ_SSR and μ_GTR were combined using a t‐norm operator, and μ_OSR was accounted for by combining μ_RSR and μ_GSR using a t‐conorm operator. The approach was applied to an area growing irrigated cotton. Cross‐validation shows predicted μ_OSR was good, with an agreement rate of 70.6%. The predicted μ_OSR was consistent with that of many areas affected by point‐source salinity. The method provides an effective way of mapping salinity hazard and risk. Incorporation of FMF provides a meaningful continuum of membership and allows the incorporation of uncertainty. Salinity risk can be calculated relative to any vegetation community and locations where management actions to moderate soil salinization can be identified.  相似文献   

Evaluation of dynamic testing for pituitary pars intermedia dysfunction diagnosis in donkeys     

S. Mejia-Pereira  A. Perez-Ecija  B. R. Buchanan  R. E. Toribio  F. J. Mendoza 《Equine veterinary journal》2019,51(4):481-488

  相似文献   

Multiple vascular anomalies in a regurgitating German shepherd puppy     

Christiansen KJ  Snyder D  Buchanan JW  Holt DE 《The Journal of small animal practice》2007,48(1):32-35

  相似文献   

Field-scale and laboratory study of factors affecting N2O emissions from a rye stubble field on sandy loam soil     

B. J. Jørgensen  Rasmus N. Jørgensen 《Biology and Fertility of Soils》1997,25(4):366-371

Emission of N₂O from cultivated and fertilised soils may contribute significantly to the total global N₂O emission. This study included laboratory and field investigations of the N₂O production from a dry stubble field as influenced by addition of water, nitrogen and glucose. N₂O fluxes were measured using a closed-chamber technique, and the O₂ content in the soil was measured using soil probes. Results from a laboratory soil core technique were correlated to the relative N₂O emission observed in the field. When the soil water content in the field increased from 14% to 60% water-filled pore space, the N₂O emission increased from non-significant to a constant emission of 30 μg N m^–2 h^–1. At this soil water content the production of N₂O was limited by the availability of nitrogen and carbon. Application of nitrogen at soil temperatures of 13 and 21°C in a pre-wetted soil increased the N₂O emission 3.1- and 3.7-fold, respectively, whereas nitrogen plus carbon application increased the N₂O emission 13.3- and 7.3-fold, respectively. In both treatments the N₂O emission rates were affected by fluctuations in soil temperature and O₂ content. The results indicate that even in a soil producing very little N₂O under dry conditions, the soil microbial community maintains a potential to produce N₂O when favourable conditions occur in terms of availability of water, nitrogen and carbon. Received: 21 October 1996  相似文献   

Snakebites Reported to the Kentucky Regional Poison Control Centers for the Years 2012-2016     

James Buchanan  Jeffrey Thurman  Charles Hargis  Lauren Kirkpatrick  Martin Huecker 《The Forestry Chronicle》2021,32(2):143-148

  相似文献