bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporal and spatial patterns of aquatic macrophyte diversity in the Upper Paraná River floodplain
Authors: Thomaz SM. , Carvalho P. , Padial AA. , Kobayashi JT.
Published: January 2010

Although the importance of long-term data has been emphasized by ecologists in recent years, little is known about how communities may change over time. In this study, we describe the general patterns of aquatic macrophyte diversity in the Paraná River floodplain observed during six years of study. Temporal changes in community composition were also evaluated. Data on the presence or absence of aquatic macrophytes were collected between March 2002 and March 2008, in six lakes associated with three rivers. Different analytical strategies were used to evaluate the dynamics of aquatic macrophyte communities between the different systems in the floodplain. The composition of aquatic macrophytes differed among the rivers, mainly with respect to the different vegetation life forms (floating, submersed, emergent and rooted with floating stems). The temporal similarity of species composition during the six years and the beta-diversity index indicated that the month-to-month species turnover was, in general, lower in the connected lakes, which are directly influenced by the river. Probably the water level fluctuation is a selective force that contributes to maintaining diversity or richness. Our findings indicated the importance of abiotic characteristics and connectivity of the lakes in determining macrophyte composition and community stability over a long time frame.
Effects of the hydrological regime on the ichthyofauna of riverine environments of the Upper Paraná River floodplain
Authors: Fernandes R. , Agostinho AA. , Ferreira EA. , Pavanelli CS. , Suzuki HI. , Lima DP. , Gomes LC.
Published: January 2010

In this work, spatial and temporal variations in the diversity (species richness and Simpson's Diversity Index) and abundance (indexed by the capture per unit effort - CPUE; total and for reproductive groups) of fish from three rivers (Baía, Ivinheima and Paraná) located in a floodplain of the Upper Paraná River basin were analyzed over a period of 20 years (1987-2007). In addition, we evaluated the relationships of these ecological attributes with variations in the hydrologic regime, considering the possible effects of natural (climatic events) and artificial (discharge control by dams) disturbances. Annual variations in hydrometric attributes were calculated using PULSO software and daily water level data. We applied analysis of covariance to determine the relationships between ecological and hydrometric attributes, the latter summarized in axes of a principal component analysis. Lower values of the fish assemblage attributes (diversity and abundance) were registered in the Paraná River. Species richness, total CPUE and CPUE of long-distance migratory species were positively related to the duration of the floods and the connectivity of the area. Variations in the annual hydrological cycle and their effects on fish assemblage appear to be affected by extreme natural (ENSO) and artificial (discharge control by dams) events.
Diversity of parasites of fish from the Upper Paraná River floodplain, Brazil
Authors: Takemoto RM. , Pavanelli GC. , Lizama MAP. , Lacerda ACF. , Yamada FH. , Moreira LHA. , Ceschini TL. , Bellay S.
Published: January 2010

The aim of the present study was to provide a current survey of the species of parasites found in the Upper Paraná River floodplain, as well as to investigate which strategies and mechanisms used by parasites, are favored and which environmental factors influence the parasite community in the studied environments. During a seven-year period from February 2000 to September 2007, 3,768 fish belonging to 72 species were collected and analyzed for the purpose of studying the parasite fauna. A total of 337 species of parasites were reported, including 12 new descriptions: one myxosporid, Henneguya paranaensis Eiras, Pavanelli and Takemoto, 2004; eight monogeneans, Kritskyia annakohnae Boeger, Tanaka and Pavanelli, 2001; Kritskyia boegeri Takemoto, Lizama and Pavanelli, 2002; Kritskyia eirasi Guidelli, Takemoto and Pavanelli, 2003; Demidospermus labrosi França, Isaac, Pavanelli and Takemoto, 2003; Demidospermus mandi França, Isaac, Pavanelli and Takemoto, 2003; Pseudovancleaveus paranaensis França, Isaac, Pavanelli and Takemoto, 2003; Tereancistrum curimba Lizama, Takemoto and Pavanelli, 2004 and Tereancistrum toksonum Lizama, Takemoto and Pavanelli, 2004; two digeneans, Sanguinicola platyrhynchi Guidelli, Isaac and Pavanelli, 2002 and Dadayius pacupeva Lacerda, Takemoto and Pavanelli, 2003 and one cestode, Nomimoscolex pertierrae Chambrier, Takemoto and Pavanelli, 2005. In addition, several other species were reported for the first time in new hosts or in the floodplain. Monogeneans presented the highest number of species, followed by digeneans. The infection site with the highest species richness was the intestine, with 127 species.
Limnology in the Upper Paraná River floodplain: large-scale spatial and temporal patterns, and the influence of reservoirs
Authors: Roberto MC. , Santana NF. , Thomaz SM.
Published: January 2010

Knowledge of abiotic limnological factors is important to monitor changes caused by humans, and to explain the structure and dynamics of populations and communities in a variety of inland water ecosystems. In this study, we used a long term data-set (eight years) collected in 10 habitats with different features (river channels, and connected and isolated lakes) to describe the spatial and temporal patterns of some of the principal limnological factors. In general, the degree of connectivity of the lakes, together with the rivers to which the lakes are connected, were important determinants of their limnological characteristics. These differences are expected, because rivers entering the floodplain come from different geological regions and are subject to different human impacts. At large spatial scales, these differences contribute to the increased habitat diversity of the floodplain and thus to its high biodiversity. With regard to temporal variation, Secchi-disk transparency increased, and total phosphorus decreased in the Paraná River main channel during the last 20 years. Although these changes are directly attributed to the several reservoir cascades located upstream, the closing of the Porto Primavera dam in 1998 enhanced this effect. The increase in water transparency explains biotic changes within the floodplain. The lower-phosphorus Paraná River water probably dilutes concentrations of this element in the floodplain waterbodies during major floods, with future consequences for their productivity.
Seed predation by rodents and safe sites for large-seeded trees in a fragment of the Brazilian Atlantic forest
Authors: Pinto SRR. , Santos AMM. , Tabarelli M.
Published: January 2010

Seed predation by small rodents is an emerging theme in the ecology of modified landscapes. Here we investigate the role played by the small rodent Oryzomys oniscus as a seed predator of large-seeded trees in a large remnant of the Atlantic forest - the Coimbra forest (3,500 ha), Alagoas state, northeastern Brazil. O. oniscus was captured and identified by setting twenty 500 m long transects, each one composed of 25 traps 20 m apart. This procedure resulted in 483 trap-nights set during a 20-mo period. We used 692 seeds (>15 mm length) from ten local large-seeded tree species for the seed predation trials that basically consisted of three treatments: one seed on the ground freely accessed by vertebrates (unprotected seed), one seed totally protected by an exclosure, and one partially-protected seed (exclosure just for medium-sized and large vertebrates). O. oniscus was captured throughout the Coimbra forest including forest edges (76 captures) and interior areas (67), and this small rodent was responsible for all seed predation visually documented inside exclosures. A 24 hours period of seed exposition permitted elevated rates of seed removal and predation. Seeds were much more removed/predated beneath fruiting trees, but rates varied according to the level of seed protection - 26.3% of predation among partially-protected versus 19.2% among unprotected seeds. Seeds suffered higher levels of seed predation/removal at the forest edge as well (up to 90%). In both habitats, most seeds (>84%) remained intact beneath trees without fruits, regardless of the level of seed protection. Our results suggest that O. oniscus may operate as an effective large-seed predator in forest fragments, in which adult trees without fruits constitute low resource spots and thereby provide, at least temporarily, safe sites for large seeds.
Detection of areas of endemism on two spatial scales using Parsimony Analysis of Endemicity (PAE): the Neotropical region and the Atlantic Forest
Authors: Sigrist Mário Sérgio , Carvalho Claudio José Barros de
Published: January 2010

An important biological challenge today is the conservation of biodiversity. Biogeography, the study of the distribution patterns of organisms, is an important tool for this challenge. Endemism, the co-occurrence of several species unique to the same area, has important implications for the preservation of biodiversity, since many areas of endemism are also areas with large human impact. More rigorously defined, areas of endemism are historical units of distributional congruence of monophyletic taxa. These areas often assumed to be due to nonrandom historical events that favored conditions associated with high rates of speciation. Thus, understanding endemism and the delimitation of endemic areas has important implications for conservation. Today, most studies delimit areas of endemism by superimposing maps of distribution for various species. This approach suffers from arbitrary delimitations, however, when a great distributional data is used. In this paper we used the method of Parsimony Analysis of Endemicity (PAE) based on georeferenced quadrats in order to delimit areas of endemism. This modality of the method is important due to its testable nature and can also be used to infer area relationships. We applied the method to raw distributional data from 19 unrelated taxa to delimit general patterns of endemism in the Neotropical Region and in the Atlantic forest domain using different grid scales. Neotropical areas found are comprised over the Panama region, northern Andean region and the Atlantic forest. Atlantic forest showed a major division into two distinct components (northern x southern). Endemic areas delimited using smaller scale grids on the Atlantic forest should be considered for conservation priorities once they showed endemism at regional and local scales. The results were also compared to other studies using different taxa and methods. Finally, some considerations on the analysis scale and future perspectives of the method are presented.
Primeiro registro de larvas de Chironomus inquinatus Correia, Trivinho-Strixino & Michailova (Diptera, Chironomidae) vivendo no casco do cágado Phrynops geoffroanus Schweigger (Testudines, Chelidae) na região Neotropical
Authors: Marques Thiago Simon , Ferronato Bruno de Oliveira , Guardia Isabela , Longo Ana Luiza Bonfin , Trivinho-Strixino Susana , Bertoluci Jaime , Verdade Luciano Martins
Published: January 2010

Neste estudo reportamos pela primeira vez a ocorrência de larvas de Chironomus inquinatus Correia, Trivinho-Strixino & Michailova vivendo no casco do cágado Phrynops geoffroanus Schweigger, possivelmente em função da intensa acumulação de sedimento, em um rio poluído da região Neotropical.
Synergy: an old wisdom, a new paradigm for pharmacotherapy
Authors: Biavatti Maique Weber
Published: January 2010

Synergy is one of the governing principles of the natural world, and is one of the reasons for the increasing complexity of the evolutionary process. Broadly speaking, it relates to the cooperative effects produced by the interaction between various forces, elements, parts or individuals in a given context. Since the last century, some clinical studies have described the increased efficiency of a combination of drugs. To study the effects of the drug interactions, the most commonly cited model is that of Loewe, and the classical graphical representation is the iso-effect curve (isobologram). Plants contain an enormous diversity of specialized micromolecules, therefore there is a high likelihood of interactions between them. Through recent synergy studies, various synergistic interactions have been demonstrated among extracts of different plants, and between components of the same extract.
Esthesioneuroblastoma (Olfactory Neuroblastoma) with Ectopic ACTH Syndrome: A Multidisciplinary Case Presentation from the Joan Karnell Cancer Center of Pennsylvania Hospital
Authors: Mintzer David M. , Zheng Sarah , Nagamine Michiko , Newman Jason , Benito Maria
Published: January 2010

The case of a patient with recurrent esthesioneuroblastoma complicated by ectopic adrenocorticotropic hormone production is presented, including the workup and management of this uncommon complication of an uncommon disease.
Outcrossing in Early‐Stage Spring Wheat Breeder Seed Development
Authors: Hucl P.
Published: January 2010

Outcrossing (OC) during the initial stages of spring wheat (Triticum aestivum L.) breeder seed development (“head‐rowing”) may lead to off‐types appearing in later generations of pedigreed seed. The objective of this research project was to measure OC in a simulated short (1.3 m) breeder row nursery of spring wheat. Rows of four cultivars known to differ in OC potential were grown at up to 12 distances (30–360 cm) from a blue aleurone pollen source in two directions in each of 2 yr. Pollen flow barriers consisted of varying numbers of border rows of wheat or the use of four rows of spring triticale (Triticosecale). The blue aleurone trait was used to estimate OC frequency. Triticale was equivalent to wheat as a pollen trap. Based on the results from this study, it would appear prudent to use a pollen barrier of at least 3.6 m between wheat germplasm of a low to moderate OC potential. Wider pollen barriers (>10 m) probably will be required for germplasm prone to OC.
Optimizing Dosages of Seaweed Extract‐Based Cytokinins and Zeatin Riboside for Improving Creeping Bentgrass Heat Tolerance
Authors: Zhang Xunzhong , Wang Kehua , Ervin E. H.
Published: January 2010

Seaweed (Ascophyllum nodosum Jol.) extract‐based cytokinins (SWEC) have been used to improve turfgrass stress tolerance, but optimum dosages for improving creeping bentgrass (Agrostis stolonifera L.) heat tolerance are lacking. This study was designed to examine effects of SWEC at various dosages on creeping bentgrass heat tolerance and to compare their effects to a trans‐zeatin riboside (t‐ZR)‐standard in a growth chamber. The SWEC and t‐ZR were applied to the foliage of ‘L‐93’ creeping bentgrass four times (14‐d interval) at 1, 10, and 100 μM. After the second application, the grass was subjected to heat stress for 49 d at 35/25°C (day/night) in the initial experiment or 38/28°C (day/night) in the second experiment. The SWEC and t‐ZR treatments at 10 and 100 μM alleviated the decline of turfgrass quality and chlorophyll content. They also increased leaf t‐ZR content and nitrate reductase (NR) activity, relative to the control, especially under 38/28°C (day/night). These data indicate that improvements under heat stress may be associated with an increase in plant t‐ZR levels and NR activity due to SWEC or t‐ZR application. Results suggest that repeated foliar application of SWEC at 10 μM may be an effective approach for improving turfgrass performance and heat stress tolerance.
Intake, Digestibility, and Nitrogen Balance of Steers Fed Gamagrass Baleage Topdressed at Two Rates of Nitrogen and Harvested at Sunset and Sunrise
Authors: Sauvé A. K. , Huntington G. B. , Whisnant C. S. , Burns J. C.
Published: January 2010

Maximum diurnal accumulation of soluble carbohydrates in warm‐season grasses is an economic way of increasing hay quality; however, in the humid East, haymaking is difficult. This study evaluated gamagrass (Tripsacum dactyloides L.), topdressed with either 56 (LO) or 168 (HI) kg N ha−1, direct baled after mowing in the afternoon (PM/LO and PM/HI) or morning (AM/LO and AM/HI), wrapped with plastic film, and conserved as baleage. The four baleage treatments were evaluated by steers for dry matter intake (DMI), digestibility, and N retention. Neither harvest time nor N rate altered DMI (mean = 1.87 kg 100−1 kg body weight). Digestion was similar between PM and AM baleage but greater (P = 0.05) for HI vs. LO N rate (536 vs. 506 g kg−1) as was cellulose digestion (P = 0.02; 656 vs. 617 g kg−1). The digestion of crude protein was greater (P = 0.01) in the AM vs. PM baleage (519 vs. 443 g kg−1) and greater (P = 0.02) in HI vs. LO N rate (520 vs. 441 g kg−1). Fermentations differed (P < 0.01) between PM and AM baleage, as pH averaged 5.4 and 4.5, respectively. Greatest (P < 0.01) amounts of alcohols and least fatty acids occurred in PM baleage and N rate reduced (P < 0.01) alcohols but increased fatty acids. Total nonstructural carbohydrates (TNC) prebaling was 120 g kg−1 in the PM and 97 g kg−1 in the AM, but baleage averaged <38 g kg−1 and explains the lack of steer response to the PM harvest. Gamagrass preserved well as baleage and was readily consumed, but the TNC fraction was not preserved.
Ozone Impacts on Assimilation and Allocation to Reproductive Sinks in the Vegetatively Propagated C4 Weed, Yellow Nutsedge
Authors: Grantz David A. , Shrestha Anil , Vu Hai‐Bang
Published: January 2010

Crop production in many irrigated agricultural regions is challenged by both air pollution and weed pressure. Impacts of ozone (O3) on C4 plants have received little attention. Yet many important crops and weeds utilize the C4 pathway, including yellow nutsedge (Cyperus esculentus L.). A previous study suggested that this species may respond to O3 exposure with enhanced allocation of biomass below ground, including potentially to reproductive tubers, an apparent exception to the general weakening of belowground sink strength. This hypothesis was not supported by the current experiments, as exposure to 60 nL L−1 and 115 nL L−1 O3 (12‐h daylight mean O3 concentration) reduced biomass allocation to tubers, relative to 4 nL L−1 Chlorophyll content, specific leaf weight, and carbon assimilation were reduced, while intercellular CO2 concentration increased, reducing water use efficiency. We conclude that (i) this C4 species exhibits substantial sensitivity to ambient O3; (ii) O3–inhibition of allocation belowground is not limited to roots but also applies to tubers; and (iii) the O3 component of global change will increase the competitiveness of nutsedge with respect to specific crops as shown previously, but will decrease tuber production and degrade water use efficiency of this challenging C4 weed.
Fine Root Distributions in Oilseed and Pulse Crops
Authors: Liu Liping , Gan Yantai , Bueckert Rosalind , Van Rees Ken , Warkentin Thomas
Published: January 2010

Fine roots are of great importance in the uptake of water and nutrients from, and input of, carbon to the soil. This study determined the proportion of extra fine (<0.4‐mm diameter) to fine (0.4‐ to 2.0‐mm diameter) roots and their distribution patterns for important oilseed and pulse crops. Crops were grown in 150‐mm diameter, 1‐m long lysimeters in the field near Swift Current, SK, in 2006–2007. For oilseeds (Brassica napus L. canola, Brassica juncea L. mustard, Linum usitatissimum L. flax), roots in the 0.0‐ to 0.2‐mm diameter class comprised about 60% of the total root length, roots in the 0.2‐ to 0.4‐mm diameter about 30%, and those in the diameter class >0.4 mm contributed a small proportion to the total. For pulses (Cicer arietinum L. chickpea, Pisum sativum L. dry pea, and Lens culinaris Medik. lentil), the proportion of roots in the 0‐ to 0.2‐mm diameter was much smaller than that for wheat (Triticum aestivum L.), whereas the proportions of roots in the thicker (0.4 to 0.6, 0.6 to 0.8, and 0.8 to 2.0 mm) diameters were greater than those for wheat. The relative distribution patterns of extra fine and fine roots in oilseeds, pulses, and wheat may provide a guide for further study of detailed rooting systems for oilseeds and pulses.
Intake and Digestibility of Improved Selections of Tall Fescue and Orchardgrass Hays
Authors: Burns J. C. , Fisher D. S.
Published: January 2010

Improved cool‐season grass cultivars may add production potential to ruminant enterprises across the North–South transition zone. Quality among hays of ‘MaxQ’ (‘Jesup’ with novel endophyte), HM4 (‘HiMag’ with novel endophyte No. 4) and ‘Cajun’ (without endophyte) tall fescues [Lolium arundinaceum (Schreb.) Darbysh.] and ‘Persist’ orchardgrass (Dactylis glomerata L.) was evaluated. Forage was harvested in the flag‐leaf stage in three of 4 yr and a regrowth (late flag‐leaf to heads‐emerging stage) in 1 yr. Goats (four trials) consumed MaxQ, HM4, and Persist similarly (P = 0.12; mean = 2.49 kg 100−1 kg body weight [BW]) and Cajun least (P < 0.01; mean = 1.62 kg × 100−1 kg BW). Apparent digestibility was similar among tall fescues (P ≥ 0.07; mean = 609 g kg−1), but MaxQ and Cajun were greater than Persist (P ≤ 0.05; mean = 610 and 623 vs. 582 g kg−1). Digestible dry matter intake (DMI) was similar among MaxQ, HM4, and Persist (P ≥ 0.09; mean 1.49 kg 100−1 kg BW). Steers (three trials and Cajun not evaluated) consumed more Persist than MaxQ (P = 0.01; 2.40 vs. 2.14 kg 100−1 kg BW) or HM4 (P = 0.01; 1.98 kg 100−1 kg BW). MaxQ had greater apparent digestibility than HM4 (P = 0.01) or Persist (P = 0.04; 626 vs. 585 vs. 597 g kg−1, respectively) but digestible DMI of MaxQ and Persist was similar (P = 0.12; mean = 1.39 kg 100−1 kg BW). Improved tall fescue cultivars, with novel endophyte, offer the ruminant producer a cool‐season forage of similar quality as orchardgrass for their enterprise.
Hormonal Changes Caused by the Xenia Effect during Grain Filling of Normal Corn and High‐Oil Corn Crosses
Authors: Liu Yue‐E , Liu Peng , Dong Shu‐Ting , Zhang Ji‐Wang
Published: January 2010

The xenia effect results from the cross‐fertilization of nonrelated lines of crops, which causes a grain to produce a germ or embryo that is much larger than average. It is a significant genetic component in TopCross grain production systems, which can affect grain yield and quality. This study measured hormone variations during grain filling of normal corn (Zea mays L.) hybrids, and normal corn crossed with a high‐oil corn. Two normal corn hybrids, Nongda 108 (ND108) and Liaoyu 20 (LY20), were used as the females. A high‐oil corn hybrid, HOC115, was used as the male. Compared with self‐fertilization, the cross between ND108 and HOC115 resulted in higher yield, while the cross of LY20 with HOC115 had lower yield. The changes in grain yield were mainly due to grain weight. Both hormone levels and endosperm cell division rates increased rapidly during the early stage of grain development, and then declined gradually until maturity. The levels of indole‐3‐acetic acid, gibberellin (GA3), zeatin riboside, and abscisic acid at an early developmental stage were closely related to the grain weight at maturity. Higher endosperm cell division rates and cell numbers were associated with lower levels of GA3, and higher filling rates were associated with higher GA3 The xenia effect was mainly mediated through changes of hormone contents, which affected endosperm cell division, grain sink strength, and, therefore, changed grain weight and grain yield.
Geochemical Modeling of Zinc Bioavailability for Rice
Authors: Gao Xiaopeng , Schröder Thomas J. , Hoffland Ellis , Zou Chunqin , Zhang Fusuo , van der Zee Sjoerd E.A.T.M.
Published: January 2010

The transition from anaerobic to aerobic rice (Oryza sativaL.) cultivation has been reported to decrease Zn bioavailability. To determine and understand the differences in plant Zn uptake between anaerobic and aerobic rice cultivation systems, a field plot experiment was conducted with direct‐seeded rice grown on a low‐Zn soil under both anaerobic and aerobic conditions. Results showed that the mass fraction of Zn in shoots and Zn uptake of plants in the aerobic field was significantly lower than in the anaerobic field. Visual Zn deficiency symptoms as whitish‐brown necrotic patches on leaves were more severe on plants grown in aerobic soils than plants in anaerobic soils, indicating reduced Zn bioavailability. To determine whether the underlying causes could be of a geochemical nature, a controlled soil incubation experiment was done. Using a fully parameterized model, we found that the difference in plant Zn uptake between the two cultivation systems was small compared with that predicted by geochemical modeling, assuming Zn uptake is controlled by the soluble fraction in the soil. Whereas individual effects of soil factors (e.g., pH) were demonstrated to cause large variations in Zn concentration, only about a 15% difference in plant Zn uptake was observed. This large discrepancy reveals that the consideration of separate soil chemical processes, instead of their integrated assessment, may be inappropriate. We speculated that the discrepancy could also be associated with the chemical conditions in the rhizosphere, where the local acidity, dissolved organic C, and redox conditions may deviate significantly from the bulk soil on which the geochemical analysis was based.
Experimental Determination of Soil Evaporation Stages with Soil Surface Temperature
Authors: Qiu Guo Yu , Ben-Asher Jiftah
Published: January 2010

Soil evaporation process can be divided into three stages: the constant‐rate, the falling‐rate, and the low‐rate stages. Soil surface temperature is closely related to the soil evaporation rate and soil evaporation stage. The objectives of this study were: (i) to propose an approach to determine the soil evaporation stage by using infrared (IR) radiometers, the three‐temperature (3T) model, and the Priestley–Taylor (PT) model; (ii) to test it on three soil types (coarse sand, sand, and clay), and (iii) to apply it using remote sensing. A drying experiment to address these objectives was continuously performed for 539 h at constant air temperature (25°C) and relative humidity (50%). The results clearly indicated that the combination of the IR radiometers and the PT model had improved the performance of the 3T model. Soil evaporation stages could be determined with the soil evaporation transfer coefficient (ha), a key parameter in the 3T model. At the constant‐rate stage, ha was a constant with low value, while cumulative evaporation (Ec) rapidly increased. At the falling‐rate stage, ha increased with Ec and the relationship between them was curvilinear. At the end of the falling‐rate stage, ha could be >0.90. Our results showed that the application of thermal imaging for the estimation of ha and the evaporation rate was promising for applying this technique in remote sensing.
Characterization by Fluorescence of Organic Matter from Oxisols under Sewage Sludge Applications
Authors: dos Santos Larissa Macedo , Bastos Débora Marcondes , Milori Pereira , Simões Marcelo Luiz , da Silva Wilson Tadeu Lopes , Pereira-Filho Edenir Rodrigues , de Melo Wanderley José , Martin-Neto Ladislau
Published: January 2010

Sewage sludge from wastewater treatment contains organic matter and plant nutrients that can play an important role in agricultural production and the maintenance of soil fertility. The present study has aimed to evaluate the degree of humification following sewage sludge application of soil organic matter by laser‐induced fluorescence and humic acids using ultraviolet‐visible fluorescence, and including comparison with Fourier‐transform infrared spectroscopy and elemental analysis. Sewage sludge applications to the soil caused a decrease in the degree of humification of the soil organic matter and humic acids for both a Typic Eutrorthox (clayey) soil and a Typic Haplorthox (sandy) soil of around 14 and 27%, respectively. This effect is probably due to incorporation of newly formed humic substances from the sewage sludge into the characteristics of less humified material, and to the indigenous soil humic substances. The minor alterations observed in the clay soil probably occurred due to both the greater mineral association, which better stabilized the indigenous soil organic matter, and the higher microbial activity in this soil, which accelerated sewage sludge mineralization. Sewage sludge applications increased the C content for the clay and sandy soils by 7.4 and 15.4 g kg−1, respectively, suggesting a positive effect on these two soils.
A Vineyard Agroecosystem: Disturbance and Precipitation Affect Soil Respiration under Mediterranean Conditions
Authors: Steenwerth Kerri L. , Pierce Danielle L. , Carlisle Eli A. , Spencer Robert G. M. , Smart David R.
Published: January 2010

We investigated impacts of agricultural management practices on soil respiration (Rs) in a Cabernet Sauvignon (Vitis vinifera) vineyard (Oakville, CA; November 2003–December 2005). We determined (i) response of Rs to cover cropping, mowing and tillage; (ii) environmental factors controlling Rs; and (iii) total annual C lost through Rs A winter cover crop was either mown (CC+mow), or mown and tilled (CC+Till), and resident vegetation was tilled (RV+Till). Precipitation amount and pattern differed between years, and low Rs rates occurred during summer drought and high rates during wet periods. Total CO2 emissions differed only in Year 2 (RV+Till: 10.99 ± 0.30, CC+Till: 10.11 ± 0.49, CC+mow: 8.57 ± 0.54 Mg CO2–C ha−1). After tillage or mowing, Rs increased five‐ to six‐fold in tilled treatments and two‐fold in the mown treatment (Year 1). In Year 2, Rs increased two‐ to three‐fold after tillage only. Rs increased after ‘post‐management’ rainfall in spring and was 1.5‐ to 2‐fold greater in tilled than mown treatments in both years due to prior incorporation of plant biomass during tillage. After fall rainfall, Rs was 1.7‐fold greater in mown than tilled treatments (Year 1). Our findings suggest that the interaction of management practice with climate and soil conditions before disturbance (i.e., management and rainfall) influenced Rs Polynomial regressions of Rs on GWC and soil temperature indicated that Rs increased until gravimetric water content (GWC) reached 14 to 15% in tilled treatments and 20% in the mown treatment, subsequently declining, indicating thresholds of GWC at which soil temperature more strongly influences Rs
Temperate Wetland Methanogenesis: The Importance of Vegetation Type and Root Ethanol Production
Authors: Williams Christopher J. , Yavitt Joseph B.
Published: January 2010

We evaluated the hypothesis that soil microorganisms inhabiting wetland soils prefer plant litter and soil organic matter to fuel methanogenesis rather than root exudates. Root ethanol production, microbial respiration, concentrations of dissolved organic C (DOC), and the biochemical composition of litter from four contrasting plant species were compared to CH4 production. Rates of CH4 production varied from as little as 67 μmol kg−1 d−1 associated with Lythrum salicaria L., to 675 to μmol kg−1 d−1 with Carex lacustris Willd., 1555 μmol kg−1 d−1 with Juncus effuses L., and 1647 μmol kg−1 d−1 with Typha latifolia L. Ethanol production was pronounced in Typha roots in the spring and autumn, and in Lythrum in midsummer, but showed little seasonal pattern in Juncus or Carex Concentrations of DOC did not vary with plant species and were greater in subsurface soil (13.3 mg C L−1 at 20 cm) than in surface soil (8.6 mg C L−1 at 5 cm). Our analysis of lignin oxidation products revealed plant‐related differences in the lignin chemistry of soil. The p‐coumaric acid content was 24 to 38% of the lignin yield in the surface soil, whereas vanillyl phenolics were dominant in the deeper soil. The ratio of acid to aldehyde was greater at depth in soils for all species except Juncus The acid/aldehyde ratio for syringyl phenolics increased with depth in soil associated with Carex Our results show that different plant species can create significant variation in soil methanogenesis, but plant‐induced differences were probably caused by variation in the biochemical composition of litter rather than root ethanol production.
Sand‐Filled Drainage Ditches for Erosion Control: Effects on Infiltration Efficiency
Authors: Widomski M. K. , Sobczuk H. , Olszta W.
Published: January 2010

A system of slope erosion control, consisting of horizontal terraces equipped with drainage ditches filled with sand, was developed in Olszanka, Poland. This system relies on combining two types of erosion control on steep slopes: limiting soil transformations and increasing the infiltration of surface water into the subsoil. The new soil erosion control system is located on a fruit farm in Olszanka. We assessed the functionality and efficiency of the system by calculating the eventual increase in infiltration gained via the drainage ditches. This assessment was performed using the numerical model FEFLOW 5.2. The calculations covered a 74‐d period (summer 2003) and relate to two groups of terraces located on different parts of the slope. The values and directions of groundwater flux and velocity resulting from the calculations were analyzed. We observed a clear increase in infiltration for terraces equipped with sand‐filled drainage ditches under real climatic conditions: 11.69 and 13.6% increases for the base and upper parts of the slope, respectively. The results were empirically verified by comparing measured in situ and calculated values of soil water content; values of R2 = 0.702 to 0.799 (P = 0.05) for four points on two terraces were determined.
Automation of the Water‐Drop Method for Soil Aggregate Stability Analysis
Authors: Jimba Samuel C. , Lowery Birl
Published: January 2010

The water‐drop method (WDM) is a long‐established and excellent means of measuring soil aggregate stability. While the WDM is very reliable, it has a drawback in that it requires manual observation of aggregate breakdown and a manual count of the number of water drops required to disperse a soil aggregate. This makes the method inconvenient and prone to error. To avoid this drawback, we propose a procedure that utilizes digital observations of aggregate breakdown and electronic recording of the water‐drop count. In this procedure, water drops from a Mariotte's tube pass through an electronic device that records the passage of each drop. The impact of water drops on the soil aggregate is digitally recorded with a camcorder. From the drop count and aggregate breakdown records, the number of water drops that strike an aggregate until it is dispersed can be determined. This procedure was evaluated using soil samples from the surface of four different soils. With the automated method, we determined the number of 4.3‐mm‐diam. water drops, each having energy of 1.67 mJ, required to destroy a 4.00‐ to 4.75‐mm‐diam. aggregate, premoistened to a matric suction of 10 kPa, until it passed through a 2.8‐mm sieve. The WDM was conducted both manually and with the automated method and the results were compared using analysis of variance (ANOVA). Twenty aggregates were used for each soil in both methods. There were no significant differences (P < 0.10) between the automated and manual methods in the mean energy required to break an aggregate.
Novel Multivariate Analysis for Soil Carbon Measurements Using Laser‐Induced Breakdown Spectroscopy
Authors: Martin Madhavi Z. , Labbé Nicole , André Nicolas , Wullschleger Stan D. , Harris Ronny D. , Ebinger Michael H.
Published: January 2010

Laser‐induced breakdown spectroscopy (LIBS), a rapid and potentially field‐deployable technology for estimating total C in soil, represents a novel approach to address important issues in soil science and C management. Our study has shown that models relating LIBS signal intensity at 247.85 nm to total C concentration determined by dry combustion vary as a function of elemental and textural characteristics of the soil, and, to a lesser extent, wavelength and excitation energy of the laser. To better quantify these sources of variation, two wavelengths and three excitation energies were used to analyze soils from various locations. The emission line of C at 247.85 nm was pronounced at an excitation wavelength of 532 nm and energy of 45 mJ, but it was largely obscured by the 248.9‐nm Fe line at 1064 nm and excitation energies of 90 and 135 mJ. Univariate analysis revealed linear but soil‐specific correlations between the signal intensity at 247.85 nm and total C concentration. A single and robust calibration model correlating LIBS spectra, collected at a laser wavelength of 532 nm and an excitation energy of 45 mJ, to C concentration in all samples was obtained using a multivariate approach. Several emission lines in addition to the strong C line contributed significantly to the multivariate model. These results show that multivariate analysis can be used to construct a robust calibration model for LIBS spectra and therein provide a reliable estimate of total soil C. Such results must be confirmed for a broader range of soils, yet crop and soil scientists, C managers, and instrument developers should find these results encouraging.
Effect of Soil Reduction on Phosphorus Sorption of an Organic‐Rich Silt Loam
Authors: Zhang Wei , Faulkner Joshua W. , Giri Shree K. , Geohring Larry D. , Steenhuis Tammo S.
Published: January 2010

Phosphorus flux from agricultural landscapes to surface waters may cause eutrophication. In the northeastern United States, P transport largely depends on P sorption of soils in variable source areas or in land treatment systems. Soil redox fluctuation commonly occurs in these areas. Nevertheless, the effect of soil redox on P sorption has been variable in the literature. This study investigated P sorption of an organic‐rich northeastern glaciated silt loam (Langford) under air‐dried, field‐wet, and reduced conditions using batch P sorption experiments. Additionally, the influence of farm wastewater on soil P sorption was studied. Major results indicated that soil reduction increased the maximum amount of P that can be sorbed (Smax) and decreased the aqueous P concentration at which P sorption and desorption are equal (EPC0), both determined from a modified Langmuir isotherm model. The slightly reduced field‐wet soils had no significant difference in Smax due to limited soil reduction. Using the diluted wastewater as the sorption solution matrices instead of 0.01 mol L−1 KCl solution, the soils generally exhibited greater Smax and lower EPC0 except for the EPC0 of a reduced surface soil, implying more complex P sorption in the field. Identified P sorption mechanisms include phosphate precipitation, ligand exchange with organic matter, and adsorption onto Fe hydroxides. Transformation of Fe compounds during soil reduction is primarily responsible for the changes in soil P sorption.
Early and Late Retirement Exits
Authors: Brougham Ruby R. , Walsh David A.
Published: January 2010

The current study proposes that personal need fulfillment (relatedness, generativity, identity, growth, and finances) predicts early and late retirement intentions. The personal needs of 160 full-time older employees were measured by personal goals, job satisfactions, job characteristics, and intrinsic motivation. Results suggest that the personal needs fulfilled by job employment remain important in retirement. The expectation for personal need fulfillment for identity, growth, and relatedness shifts from work to retirement for those who intend to retire early. The results are discussed in terms of the need for greater study of the relationship between expectations of personal need fulfillment, worker self-concept, and retirement decisions.
The Science of Recruiting: Implementing the Vision of Diversity
Authors: Farquhar Jessica Anderson , Jewell Angela
Published: January 2010

There are multiple levels of involvement and influence in the process of recruiting minority students. The tiers of communication between an institution and a potential applicant can be visually depicted by the “recruitment funnel,” where a large pool of prospective students is narrowed, by specific outreach efforts, to represent those who actually inquire into your program, submit an application, and eventually enroll. Ultimately, those who are admitted must first apply. This article offers four specific strategies for success that pertain to the growing need for diversity in the future population of veterinary students. These four, ranging from composing your recruitment team to prioritizing line items for your budget, can serve to increase the quantity and quality of your next pool of high-quality minority applicants.
Recommendations of the International Medical Informatics Association (IMIA) on Education in Biomedical and Health Informatics
Authors: Ammenwerth E. , Demiris G. , Hasman A. , Haux R. , Hersh W. , Hovenga E. , Lun K. C. , Marin H. , Martin-Sanchez F. , Wright G. , Mantas J.
Published: January 2010

Objective: The International Medical Informatics Association (IMIA) agreed on revising the existing international recommendations in health informatics /medical informatics education. These should help to establish courses, course tracks or even complete programs in this field, to further develop existing educational activities in the various nations and to support international initiatives concerning education in biomedical and health informatics (BMHI), particularly international activities in educating BMHI specialists and the sharing of courseware.

Method: An IMIA task force, nominated in 2006, worked on updating the recommendations’ first version. These updates have been broadly discussed and refined by members of IMIA’s National Member Societies, IMIA’s Academic Institutional Members and by members of IMIA’s Working Group on Health and Medical Informatics Education.

Results and Conclusions: The IMIA recommendations center on educational needs for health care professionals to acquire knowledge and skills in information processing and information and communication technology. The educational needs are described as a three-dimensional framework. The dimensions are: 1) professionals in health care (e.g. physicians, nurses, BMHI professionals), 2) type of specialization in BMHI (IT users, BMHI specialists), and 3) stage of career progression (bachelor, master, doctorate).

Learning outcomes are defined in terms of knowledge and practical skills for health care professionals in their role a) as IT user and b) as BMHI specialist. Recommendations are given for courses /course tracks in BMHI as part of educational programs in medicine, nursing, health care management, dentistry, pharmacy, public health, health record administration, and informatics /computer science as well as for dedicated programs in BMHI (with bachelor, master or doctor degree).

To support education in BMHI, IMIA offers to award a certificate for high-quality BMHI education. It supports information exchange on programs and courses in BMHI through its Working Group on Health and Medical Informatics Education.
Incomplete Seating of a Metal-backed Alumina Liner in Ceramic-on-Ceramic Total Hip Arthroplasty
Authors: Carvajal Alba Jaime A. , Schiffman Eric D. , Scully Sean P. , Parvataneni Hari K.
Published: January 2010

Metal-backed modular ceramic bearing systems using a recessed alumina liner in a titanium sleeve were developed to decrease ceramic chipping or fracture due to femoral neck impingement after total hip arthroplasty (THA). However, malseating of the metal-backed ceramic liner has recently been described. The goal of this study was to assess the prevalence, etiology, and clinical relevance of this event.

Between 2005 and 2008, 51 consecutive patients (61 hips) underwent THA with a metal-backed alumina liner housed in a titanium shell. The metal-backed ceramic liner was aligned, seated, and impacted into the shell, and satisfaction in terms of liner stability and seating was confirmed intraoperatively. Postoperative assessment of seating was assessed with standard radiographs. Liner seating was classified as well seated, suspicious, or malseated.

Seven liners (11.5%) were found to be malseated and 4 (6.5%) were considered suspicious. Radiographically, there was a gap between the liner and the shell located inferomedially in 4 patients and superolaterally in 3 patients. Two liners subsequently seated at 1 and 3 months postoperatively, respectively. No dislodgement, failures, or adverse events were identified. There were no revision surgeries. The significant percentage of malseated liners were potentially attributed to poor exposure, bony/soft tissue interposition, and surgeon learning curve.
The Strength and Effects of Humeral Rotation on Single-Versus Double-Row Repair Techniques in Small Rotator Cuff Tears
Authors: Shah Anup A. , Milos Steven , Deutsch Allen
Published: January 2010

With advanced surgical techniques, instrumentation, and implants, arthroscopic rotator cuff repair has become increasingly popular. As the techniques continue to evolve, so do the methods by which the repairs are tested. Cyclic loading has shown to better replicate postoperative motion after cuff repair. Recently, cyclic loading with dynamic external rotation has been studied for large rotator cuff repairs. Our study applies this concept to small, isolated supraspinatus tears, comparing single- vs double-row repair techniques.

A 1.5-cm rotator cuff tear was created in cadaveric specimens and repaired with single-and double-row repair techniques. With cyclic loading and dynamic external rotation, gap formation and ultimate pullout strength were determined and found to be equivalent. This study demonstrates no significant difference in single- vs double-row repairs for small, isolated supraspinatus tears when tested with cyclic loading and dynamic external rotation.
Pathologic Correlation of Posterior Ligamentous Injury With MRI
Authors: Dekutoski Mark B. , Hayes Meredith L. , Utter Andrew P. , Szatkowski Jan P. , Port John D. , Wald John T. , Inwards Carrie Y. , Vaccaro Alexander R. , Fehlings Michael G.
Published: January 2010

This article describes 2 cases of spinal trauma in which diagnostic magnetic resonance imaging (MRI) was correlated with histopathology for diagnosis of a posterior ligamentous complex injury. Spine fractures are common and represent up to 16% of traumatic fractures. Diagnostic imaging currently involves plain films and computerized tomography, but MRI is being used with increasing frequency. The definition of neurologic tissue injury has had substantial documentation in the spinal literature. Clinically, posterior ligamentous complex injury has been associated with facet disruption, gapping of the spinous processes, and significant kyphosis. Assessment of spinal stability in the spine trauma population is based significantly on the assumed disruption or integrity of the posterior ligamentous complex. High signal intensity in the area of the ligamentum flavum and interspinous ligament on fat-saturated T2 MRIs has been associated with the clinical finding of interspinous ligament disruption noted at surgical exploration. Magnetic resonance imaging in spine trauma is widely accepted despite a paucity of data addressing its histopathologic accuracy. To our knowledge, histopathologic correlation of MRI of ligamentous injuries has not been reported.