bluuebunny/crossref_metadata_2025 huggingface dataset:
Birds foraging for fruits and insects in shrubby restinga vegetation, southeastern Brazil
Authors: Gomes Verônica Souza da Mota , Loiselle Bette A. , Alves Maria Alice S.
Published: January 2010

Understanding how birds use vegetation to obtain food resources has implications for habitat conservation and management. Restinga is a poorly known and threatened tropical habitat, associated to the Atlantic forest, that could benefit from this kind of information to know which plants can be used and dispersed by birds that can help on the maintenance of this habitat. Frugivorous and insectivorous birds are important components of tropical ecosystems, such as restinga. To provide more information regarding the ecology of restinga, we studied the feeding behavior and spatial use of this vegetation by birds at Restinga de Jurubatiba National Park, southeastern Brazil. We found that feeding behavior was similar to that recorded for the same species in other vegetation types. In addition, spatial use of the restinga vegetation by the most abundant species did not overlap greatly, except for two insectivorous species that used different foraging maneuvers and two frugivorous birds that foraged in flocks. The two most abundant species were generalists in their diet and were capable of feeding at the ground level on sand substrate.
Loricate Choanoflagellates from the South Atlantic coastal zone (~32 °S) including the description of Diplotheca tricyclica sp. nov.
Authors: Bergesch Marli , Odebrecht Clarisse , Moestrup Øjvind
Published: January 2010

The biodiversity of marine heterotrophic protists is poorly known in the South Atlantic coastal zone (~32 °S) especially regarding the nanoflagellates. The presence of loricate choanoflagellates was reported for the first time in the Patos Lagoon estuary and the adjacent coastal zone. Seventeen species of eleven genera of loricate choanoflagellates were observed between October 1998 and May 2000 in fixed water samples (lugol's solution + glutaraldehyde) in a JEM 100-SX transmission electron microscope. Most species were recorded in euhaline and mixopolyhaline waters during the spring and summer, none in autumn and a few (four) in winter. The absence of choanoflagellates at the more sheltered inshore stations is due freshwater influence, and at the beach station, probably due the strong wave action. The probably cosmopolitan species Pleurasiga minima, Cosmoeca norvegica, C. ventricosa and Parvicorbicula circularis were present in spring or summer in the estuary channel and coastal area while Stephanoeca diplocostata which apparently prefers lower temperature, was recorded in winter. Calotheca alata and Campyloacantha spinifera are mainly temperate species and were present in spring. The new species Diplotheca tricyclica was recorded at the estuary channel in the summer 1999, in high salinity water.
Avaliação do refluxo venoso superficial ao mapeamento dúplex em portadores de varizes primárias de membros inferiores: correlação com a gravidade clínica da classificação CEAP
Authors: Andrade Áurea Regina Teixeira de , Pitta Guilherme Benjamin Brandão , Castro Aldemar Araújo , Miranda Júnior Fausto
Published: January 2010

Contexto: As alterações de pele manifestadas na insuficiência venosa crônica têm como etiologia mais comum o refluxo venoso. Alguns autores relatam que o refluxo venoso superficial é responsável por 40-60% das úlceras de perna nos portadores de varizes primárias. Objetivo: Correlação do refluxo venoso superficial ao mapeamento dúplex com o quadro clínico (classificação CEAP - clínica, epidemiológica, anatômica e fisiopatológica) nos portadores de varizes primárias de membros inferiores. Método: Estudo transversal e descritivo, desenvolvido em portadores de varizes primárias. As variáveis primárias foram: refluxo venoso e quadro clínico. O quadro clínico foi caracterizado por grupos: A, B e C, representados pelas categorias clínicas da CEAP. Dados complementares foram: tipos de refluxo em veias safenas magnas e parvas, conforme classificação de Engelhorn (2004). Testaram-se as hipóteses de inter-relações entre presença de refluxo e quadro clínico, utilizando-se os testes exato de Fisher e qui-quadrado no nível de 5% de probabilidade. Resultados: Das 242 extremidades inferiores examinadas, 15 foram excluídas, totalizando 227 na amostra final. Noventa e nove (83,9%) pacientes eram do sexo feminino. A média de idade foi de 50 anos, com mediana igual a 49 anos. Noventa e três extremidades (41%) não apresentavam refluxo, e 134 (59%) o apresentavam isolado e/ou associado. O refluxo isolado em veias perfurantes (p = 0,0008) e destas em associação com o refluxo em veias safenas magnas (p < 0,0001) estão significativamente relacionados à gravidade do quadro clínico. Conclusão: Há correlação entre a presença do refluxo venoso superficial ao mapeamento dúplex e a gravidade do quadro clínico nos portadores de varizes primárias de membros inferiores.
Consciência crítica com ciência idealista: paradoxos da redução sociológica na fenomenologia de Guerreiro Ramos
Authors: Faria José Henrique de
Published: January 2010

O propósito deste artigo é elaborar uma crítica da concepção de Guerreiro Ramos nos estudos organizacionais a partir das suas contribuições mais conhecidas, consultadas e referenciadas, de forma a compreender seus fundamentos e suas vinculações, com o objetivo de defender a tese de que as análises críticas de Guerreiro Ramos não autorizam incluí-lo ou considerá-lo como vinculado à Teoria Crítica. As posições críticas de Guerreiro Ramos, conforme será mostrado, baseiam-se no emprego que faz em suas reflexões da fenomenologia, especialmente a de Husserl. Para defender a tese proposta, as análises serão realizadas do ponto de vista da Teoria Crítica. Para tanto, este estudo está organizado em três partes. Na primeira, tratará dos contornos conceituais do que se entende por Teoria Crítica e fenomenologia, de maneira a fundamentar a análise. Na segunda, exporá a proposta da redução sociológica formulada por Guerreiro Ramos, agregada à sua crítica à sociologia brasileira e à proposição de uma nova ciência das organizações. Na terceira, encaminhará uma análise crítica objetiva da concepção de Guerreiro Ramos, tendo por base uma postura metodológica que integra o significado das obras criticadas nos fatos, levando em consideração o significado de sua produção intelectual e a vinculação com a situação existencial.
Short-term variability and transport of nutrients and Chlorophyll-a in Bertioga Channel, São Paulo State, Brazil
Authors: Gianesella Sônia Maria Flores , Saldanha-Corrêa Flávia Marisa Prado , Miranda Luiz Bruner de , Corrêa Marco Antonio , Moser Gleyci Aparecida Oliveira
Published: January 2010

Short-term variability of nutrients, chlorophyll-a (Chl-a) and seston (TSS) concentrations were followed up at a fixed station in the Bertioga Channel (BC), Southeastern Brazil, over two full tidal cycles of neap and spring tides, during the winter of 1991. Simultaneous data on hydrographic structure, tidal level and currents allowed the computation of the net transport of those properties. Tidal advection and freshwater flow were the main forcing agents on the water column structure, nutrient availability and Chl-a distribution. Dissolved inorganic nitrogen and phosphate average values were high (16.88 and 0.98 ¼M, respectively, at neap tide and 10.18 and 0.77¼M at spring tide). Despite N and P availability, Chl-a average values were low: 1.13 in the neap and 3.11 mg m-3 in the spring tide, suggesting that the renovation rate of BC waters limits phytoplankton accumulation inside the estuary. The highest Chl-a was associated with the entrance of saltier waters, while the high nutrient concentrations were associated with brackish waters. Nutrients were exported on both tides, TSS and Chl-a were exported on the spring tide and Chl-a was imported on the neap tide. The study of the main transport components indicated that this system is susceptible to the occasional introduction of pollutants from the coastal area, thus presenting a facet of potential fragility.
Instantaneous transport of salt, nutrients, suspended matter and chlorophyll-a in the tropical estuarine system of Santos
Authors: Moser Gleyci A. O. , Gianesella Sônia Maria Flores , Alba José Juan Barrera , Bérgamo Alessandro Luvizon , Saldanha-Corrêa Flávia M. P. , Miranda Luiz Bruner de , Harari Joseph
Published: January 2010

The contribution of the polluted São Vicente and Santos estuarine channels to the eutrophication of Santos bay was assessed through the quantification of instantaneous transport of salt, dissolved inorganic nitrogen (DIN) and phosphate, organic and inorganic matter (OSM and ISM) and chlorophyll-a (Chl-a), during dry (austral winter- August/ 1999) and rainy (austral summer- January/2000) seasons. Samplings were carried out during spring and neap tides, in flood and ebb phases, in two transversal sections at the mouths of the São Vicente and Santos channels. Instantaneous transport values generally indicated importation of salt to the estuarine channels, exportation of DIN to the bay, mainly as N-NH4, at a maximum rate of 1155.1 g s-1 during the rainy season; importation of phosphate during the dry season (maximum of 385 g s-1) and exportation of ISM, OSM and Chl-a during periods of greater freshwater discharge. These results demonstrate the great contribution made by the Santos and São Vicente estuaries to the eutrophication of Santos bay, especially in the rainy season.
A numerical study of the Plata River plume along the southeastern South American continental shelf
Authors: Pimenta Felipe M. , Campos Edmo José Dias , Miller Jerry L. , Piola Alberto R.
Published: January 2010

The Rio de la Plata, one of the largest rivers on Earth, discharges into the ocean waters from basin that covers a large area of South America. Its plume extends along northern Argentina, Uruguay, and southern Brazil shelves strongly influencing the ecosystems. In spite of this, little is known about the mechanisms that control it. Here we report results of simulations with POM carried out to investigate the roles of wind and river discharge in Plata plume dynamics. Different outflows were explored, including an average climatological value and magnitudes representative of La Niña and El Niño. Forcing the model with river discharge the average plume speed was directly related to the outflow intensity. The Plata northward extension varied from 850 to 1550 km and for average discharge a band of low salinity waters formed from the estuary up to 30ºN of South Brazilian Shelf. Upwelling and downwelling winds were applied after 130 days. The distribution of low salinity waters over the shelf was more sensitive to the wind direction than to the river outflow variability. Downwelling winds were very capable of advecting the low salinity signal downshelf. Upwelling winds were efficient in eroding the plume, which was basically detached from the coast by Ekman drift. Abnormal plume intrusions toward low latitudes may be a result of the original plume position coupled with events of persistent strong downwelling favorable winds.
Prevalência e fatores associados ao tabagismo em estudantes de medicina de uma universidade em Passo Fundo (RS)
Authors: Stramari Leandro Mazzoleni , Kurtz Munique , Silva Luiz Carlos Corrêa da
Published: January 2010

OBJETIVO: Verificar a prevalência e fatores associados ao tabagismo entre os acadêmicos de medicina e avaliar o perfil desse grupo. MÉTODOS: Responderam a um questionário autoaplicável, contendo perguntas sobre consumo e atitudes relacionadas ao tabagismo, 316 acadêmicos de medicina (98,7% do total) da Universidade de Passo Fundo. Segundo recomendações da Organização Mundial da Saúde, os estudantes foram classificados em fumantes diários, fumantes ocasionais, ex-fumantes ou não-fumantes, sendo considerados fumantes ativos os nas duas primeiras categorias. RESULTADOS: Observou-se que 16,5% dos acadêmicos eram fumantes ativos (5,4% diários e 11,1% ocasionais) e 3,5% eram ex-fumantes. A média de idade foi 22,2 ± 2,4 anos. Os fatores significativamente associados ao tabagismo (p < 0,05) foram sexo masculino, pai fumante, uso regular de bebidas alcoólicas e uso de antidepressivos ou ansiolíticos. Verificou-se que 69,2% dos fumantes iniciaram o tabagismo entre 15 e 19 anos, tendo como principais motivações a vontade própria e/ou a influência de amigos. A conceituação do tabagismo como doença foi significativamente maior entre os não-fumantes. Quanto à carga tabágica, 70,6% dos fumantes consumiam 1-10 cigarros por dia. Entre os fumantes, 67,3% já tentaram parar de fumar, 96,0% acreditam serem capazes de fazê-lo e 87,2% pretendem deixar de fumar, ao passo que 92,3% admitiram que o cigarro faz mal à saúde. CONCLUSÕES: A prevalência do tabagismo ainda é significativa entre os acadêmicos de medicina, sendo fundamental estabelecer estratégias preventivas e de cessação mais efetivas a fim de se tentar reduzir o número de fumantes entre os futuros médicos.
Climatic and Genotypic Effects for Grain Yield in Maize under Stress Conditions
Authors: Romay M. Cinta , Malvar Rosa A. , Campo Laura , Alvarez Angel , Moreno‐González Jesús , Ordás Amando , Revilla Pedro
Published: January 2010

Climate change is expected to affect agriculture. Yield stability across environments is a critical breeding goal when dealing with unstable climate and input reductions in farming systems. The objective of this study was to determine climatic and genetic factors contributing to genotype (G), environment (E), and genotype × environment (GE) variability for maize (Zea mays L.) grain yield under some stress conditions like drought, cold, and pest attack. A large sample of Spanish maize populations was evaluated along with checks at three diverse locations during 3 yr. Factorial regression was performed to obtain a biological explanation of the G, E, and GE interaction for yield. The commercial hybrids had more yield and stability than most populations; therefore, breeding programs focusing on yield have released hybrids with high yield and stability under stress conditions. The populations with a reasonable compromise between yield and stability were Andoain and Lira. The main genotypic covariate was kernel depth, followed by ear length, although other covariates were important for each location. The main climatic covariates for yield were related to days with mean temperature over 15°C and maximum temperature in September, but they were not consistent across locations. Therefore, if yield under stress conditions is a breeding goal, several climatic variables, especially those related to high temperatures, and genotypic traits such as kernel depth and ear length should be considered.
Variability for Freezing Tolerance among 42 Ecotypes of Green‐Type Annual Bluegrass
Authors: Dionne Julie , Rochefort Sophie , Huff David R. , Desjardins Yves , Bertrand Annick , Castonguay Yves
Published: January 2010

Limited information exists on the extent of genetic variability for freezing tolerance among perennial biotypes of annual bluegrass (Poa annua L.) that evolved under golf greens management. We characterized the freezing tolerance of 42 ecotypes collected across the United States and in Québec using plants hardened to low temperatures during fall and winter. We subsequently analyzed cold‐induced biochemical changes in a subset of ecotypes with varied levels of tolerance. There was a large variability among ecotypes for freezing tolerance expressed as the lethal temperature for 50% of the plants (LT50) with values ranging from <−27.0 to −17.0°C. Variation was observed between ecotypes originating from the same region and even the same golf course. Ecotypes from Québec—better insulated from extreme subfreezing temperatures by reliable and abundant snow cover—developed less freezing tolerance than those evolving under milder winter climates. Significant differences in the concentrations of specific amino acids and carbohydrates were observed among ecotypes. Only fructans of high molecular weight, however, were significantly correlated with freezing tolerance and accounted for as much as 50% of the LT50 variance. A 26‐kDa polypeptide that markedly accumulated in cold acclimated crowns was more abundant in plants from Québec. Extensive genetic variability for freezing tolerance among perennial biotypes of annual bluegrass can thus be exploited to mitigate winter damage to golf greens.
Three Soybean Plant Introductions Possess Unique Resistance to Peanut Root‐Knot Nematode
Authors: Yates Jennifer L. , Hussey Richard S. , Finnerty Steven L. , Boerma H. Roger
Published: January 2010

Peanut root‐knot nematode [Meloidogyne arenaria (Neal) Chitwood or Ma] is an increasingly common pest in the southern United States where crops such as peanut (Arachis hypogaea L.) and soybean [Glycine max (L.) Merr.] are grown. Four soybean plant introductions (PIs) are highly resistant to the peanut root‐knot nematode. To determine if PI 594403, PI 594427C, and PI 594651B contain useful resistance genes from those previously characterized in PI 200538, populations developed from the PIs crossed to PI 200538 were tested for Ma response. Highly galled and highly resistant F2 plants were observed in each population. In two of the three populations, the highly galled F2 plants produced progeny that sustained significantly greater galling (P < 0.001) than those derived from highly resistant F2 plants. While the F2–derived progeny from the third population had more variability than was observed in the other crosses, progeny means of the lines were significantly different (P < 0.05). Individual F2–derived lines from highly galled or resistant F2 plants within all of the populations were significantly different from each other or from the parents. Thus, it is evident that these PIs likely contain unique resistance genes that, when combined with PI 200538–derived Ma resistance, could improve the level of Ma resistance in soybean cultivars.
Breeding Maize for a Bioeconomy: A Literature Survey Examining Harvest Index and Stover Yield and Their Relationship to Grain Yield
Authors: Lorenz A. J. , Gustafson T. J. , Coors J. G. , de Leon N.
Published: January 2010

The use of maize (Zea mays L.) stover as a feedstock for cellulosic biofuels production will create demand for maize hybrids with greater stover yield. It is expected that grain yield will remain the most critical trait and continue to drive hybrid sales, requiring that any increases in stover yield be made without sacrificing grain yield potential. The objective of this review was to determine the relationship between grain yield, harvest index, and stover yield to illuminate the potential for increasing both grain and stover yield through breeding. In contrast to what has been observed in other crops, gains in maize grain yield over time in the U.S. Corn Belt have been accompanied by increases in stover yield. Where recurrent selection on grain yield has been most successful, stover yield also increased while harvest index has been relatively stable. The opposite situation has been observed in tropical germplasm, where gains in grain yield have been associated with increasing harvest index and relatively constant biomass yield. We expect that stover yield of Corn Belt hybrids will continue to increase along with grain yield, resulting in future hybrids capable of producing both more food and biofeedstock for energy production. If maize breeders pursue selection for increased stover yield, we found no evidence to suggest that breeding for stover yield will necessarily reduce rate of gain in grain yield.
Varietal Differences and Morphology of Cleistogamy in Soybean
Authors: Benitez Eduardo R. , Khan Nisar A. , Matsumura Hisakazu , Abe Jun , Takahashi Ryoji
Published: January 2010

Cleistogamy, the production of open (chasmogamous, CH) and closed (cleistogamous, CL) floral forms by one species, is present in soybean [Glycine max (L.) Merr.]. Soybean cultivars that originated from high latitudes generally have a strong tendency to produce CL flowers. The first objective of this study was to determine varietal differences in cleistogamy. The second objective was to observe morphological differences between CH and CL flowers. A total of 32 and 31 soybean cultivars (maturity groups 00 to II) were grown in fields at Tsukuba and Sapporo, Japan, respectively, in 2005. Flowers that were fertilized up to 5 d after anthesis were classified into either CH or CL. Frequency of CL flowers ranged from 0.0 to 100.0% in Tsukuba and 6.7 to 100.0% in Sapporo. Cultivars from Russia and Hokkaido generally had a high frequency of CL flowers, whereas those from the Tohoku region had a lower frequency. Average of mean temperatures for 1 wk before anthesis was negatively correlated with frequency of CL flowers. Growth chamber experiments were conducted using CL cv. Severnaya 4 and a CH cv. Toyosuzu under constant temperatures of 25°C to eliminate temperature effects. Frequency of CL flowers in Severnaya 4 and Toyosuzu was 33.7 and 92.8%, respectively, suggesting involvement of genetic factors. At the same developmental stage, CL flowers had shorter sepal, petal, and stamen than CH flowers. There was no distinct morphological change in floral organs between CH and CL flowers except for length of the organs.
Conserving and Enhancing Maize Genetic Resources as Global Public Goods–A Perspective from CIMMYT
Authors: Ortiz Rodomiro , Taba Suketoshi , Tovar Víctor H. Chávez , Mezzalama Mónica , Xu Yunbi , Yan Jianbing , Crouch Jonathan H.
Published: January 2010

The growing demands for food, feed, and bioenergy worldwide will require a 2% per annum increase in global maize (Zea mays L.) production. Maize is one of the most important staple food crops across the developing world as well as being an important feed crop for global livestock production and the emerging biofuel industry. Maize genotypes can range from 0.5 to 5 m standing height at flowering, mature in 60 to 330 d from planting, produce 1 to 4 ears per plant, 10 to 1800 kernels per ear and yield from 0.5 to 23.5 Mg of grain per hectare. Even greater genetic diversity is present in related species yet surprisingly little of the maize‐related biodiversity is present in the current elite breeding pools. Improved methods and tools for germplasm conservation, characterization, and data sharing, as well as for population improvement, gene pool enhancement, and genomics‐aided breeding are urgently needed if increases in maize productivity, particularly in the developing world, are to keep pace with predicted increases in demand. Progress in the private sector, particularly with the development of temperate maize cultivars, is far beyond that of the public sector, particularly regarding tropical maize cultivar development. This article provides an overview of progress at the International Maize and Wheat Improvement Center (CIMMYT) with national partners across the developing world. Particular emphasis is given to issues related to the continued development of elite maize breeding material as global public goods, especially regarding the introgression of new variations from genetic resources and the legal and phytosanitary issues related to international exchange of maize germplasm.
Long‐Term Nitrate Leaching Under Vegetable Production with Cover Crops in the Pacific Northwest
Authors: Feaga Jeffrey B. , Selker John S. , Dick Richard P. , Hemphill Delbert D.
Published: January 2010

Nitrate (NO3−–N) lost through leaching contaminates the groundwater in many agricultural areas. Understanding the relationship between leaching and climate is an important consideration for developing nutrient management strategies. Soil water was sampled for 11 yr under plots with summer vegetables grown in the Willamette Valley, Oregon, with and without winter cover crops. A randomized complete‐block, split‐plot design was employed with three N fertilizer application rates (N0 for no fertilizer, N1 for an intermediate input, and N2 for a full, recommended N input). Fall‐seeded cover crops included cereal rye (Secale cereale L. var. Wheeler), triticale (Triticosecale X L. var. Celia), and a common vetch (Vicia sativa)/triticale mix. Twenty‐six, 0.26‐m2 passive capillary samplers (PCAPS), which are capable of sampling in unsaturated and saturated conditions, allowed for the uninterrupted measurement of soil water and solute flux at a depth of 1.2 m. Eleven‐year flow‐weighted average NO3−–N concentrations (mg L−1) for fallow (F) and cover cropped (CC) treatments were 16.7 and 11.9 for the N2 fertilizer treatment, 9.9 and 6.4 for the N1 fertilizer treatment, and 7.0 and 4.1 for the N0 treatment. Annual average NO3−–N mass losses (kg ha−1) for F and CC treatments were 76 and 46 for the N2 fertilizer treatment, 40 and 30 for the N1 fertilizer treatment, and 29 and 17 for the N0 treatment. Fully fertilized CC and F treatments consistently exceeded the EPA's 10 mg L−1 drinking water standard set for NO3−–N. The timing and quantity of yearly rainfall, particularly from October to December, was a dominant contributor to the fluctuations of NO3−–N concentrations and mass losses. Soil NO3−–N and bromide soil concentration profiles suggested that high leaching losses in leaching Year 2001 were related to the previous drier‐than‐average winter and the early arrival of rainfall following the vegetable harvest. The long‐term water quality benefits observed under the CC treatments suggest that an increase in organically bound N is occurring.
Changes in Properties of Sodic Australian Vertisols with Application of Organic Waste Products
Authors: Ghosh Subhadip , Lockwood Peter , Hulugalle Nilantha , Daniel Heiko , Kristiansen Paul , Dodd Kylie
Published: January 2010

In Australia, the surface and subsurface soils of the majority of cotton (Gossypium hirsutum L.)‐growing regions are sodic. Application of organic amendments can be an option to stabilize the structure of sodic Vertisols due to their potential positive effect on soil physical properties. An incubation experiment was conducted for 4 wk in a temperature‐controlled (30°C) growth chamber to study the effect of organic amendments on the properties of two Vertisols with different sodicity levels. The exchangeable Na percentages (ESPs) in these Vertisol soils collected from the Australian Cotton Research Institute (ACRI) near Narrabri, New South Wales, and a commercial cotton farm near Dalby, Queensland, were modified such that three different sodicity levels resulted, i.e., nonsodic (ESP < 6), moderately sodic (ESP 6–15), and strongly sodic (ESP > 15). The organic amendments used were cotton gin trash (60 Mg ha−1), cattle manure (60 Mg ha−1), and composted chicken manure (18 Mg ha−1), as well as an unamended control. The organic amendments improved the physical properties of both Vertisols by decreasing clay dispersion. In the Dalby soil, cotton gin trash produced the largest decrease (29%) in the dispersion index over the control at the moderate sodicity level, whereas in the strongly sodic soil, the lowest dispersion index resulted from the application of chicken manure. Nutrient availability (N, P, and K) was also increased significantly at higher sodicity levels for both the ACRI and Dalby soils by using organic amendments. These results indicate that using organic amendments can be beneficial for the amelioration of sodic Vertisols and also to sustain soil quality.
Nitrogen Transformations and Microbial Communities in Soil Aggregates from Three Tillage Systems
Authors: Muruganandam Subathra , Israel Daniel W. , Robarge Wayne P.
Published: January 2010

Quantifying N transformation processes in soil aggregates is relevant since microbial communities central to the N cycle may differ among aggregate size fractions. Our objective was to test the hypothesis that variations in microbial community composition of aggregate size fractions influence N transformation rates of soil from three long‐term (22‐yr) tillage systems (no‐till, chisel plow, and moldboard plow). Aggregate size fractions (2–4, 0.5–1, and <0.25 mm) were obtained by dry sieving. Nitrogen transformation rates were estimated by analysis of 15N pool dilution data with the FLUAZ model, and microbial community composition by phospholipid fatty acid (PLFA) profiles. Aggregate size fraction and tillage system had significant (P < 0.01) effects on total and microbial biomass C and N, gross N mineralization rate (GNMR), gross nitrification rate (GNR), and gross N immobilization rate (GIR). No‐till soils and the 0.5‐ to 1.0‐mm aggregate size fraction had the highest N transformation rates. Net N mineralization rates were greater for no‐till than for tilled soils. Multiple response permutation analysis of PLFA data revealed that microbial community composition did not differ with aggregate size fraction. Stepwise regression analysis indicated that microbial community composition (nonmetric multidimensional scaling Axis 1) accounted for 89% of the variation in GIR, soil C and N concentrations accounted for 88% of the variation in GNMR, and microbial biomass C concentration accounted for 81% of the variation in GNR. These results indicate that greater N transformation rates in no‐till than tilled soil were due primarily to increased microbial biomass (i.e., microbial population size) rather than altered microbial community composition.
Evaluation of β‐Glucosidase Activity as a Soil Quality Indicator for the Soil Management Assessment Framework
Authors: Stott D. E. , Andrews S. S. , Liebig M. A. , Wienhold B. J. , Karlen D. L.
Published: January 2010

The Soil Management Assessment Framework (SMAF) was developed to assess conservation effects on soil, and uses multiple soil quality indicator measurements to compare soil functioning. Our objective was to develop a SMAF‐compatible scoring equation for soil β‐glucosidase (BG) activity using published data sets representing different soils and management. The resulting equation was an S‐shaped curve: y = a/[1 + bexp(−cx)], where x is the measured BG activity (mg p‐nitrophenol [PNP] released kg−1 soil h−1), a and b are constants, and c is a factor modified by soil classification, texture, and climate. Data from a study conducted near Mandan, ND were used to test the model for sensitivity to crop management systems. Soil organic C (SOC) content at the site measured 247 to 687 g kg−1, while BG activity ranged from 33 to 675 mg kg−1 h−1 Using SMAF, SOC indicator scores ranged from 0.25 to 0.73, while BG activity scores varied from 0.17 to 0.93. As the work progressed, it became apparent that when BG activity values were normalized to the SOC content, the resulting ratio could indicate C sequestration trends, with ratios of 10 to 17 g PNP kg−1 SOC h−1 reflective of systems in equilibrium. Ratios >17 were mostly from recently altered management systems with SOC contents trending upward, while ratios <10 were generally from soils that were expected to continue to lose soil C. The application of a sensitive C cycling enzyme activity such as BG should improve the SMAF soil quality assessments for soil functions where soil metabolic activity or C‐cycle enzyme activity play a role.
Biogeochemical Influences Associated with Sedimentation in Riparian Forests of the Southeastern Coastal Plain
Authors: Jolley Rachel L. , Lockaby B. Graeme , Governo Robin M.
Published: January 2010

The importance of riparian forests in maintaining water quality through the retention of sediments and nutrients is well understood; however, little is known about how sediment deposition from upland erosion affects the integrity of these systems. The objectives of this study were to compare decomposition rates, net N mineralization rates, microbial biomass, and other soil properties along a gradient of sedimentation rates in headwater systems. These factors were measured in 17 plots situated within riparian forests of ephemeral streams at Ft. Benning, GA. The soils were analyzed for texture, pH, cation exchange capacity (CEC), and bulk density. A decline in soil quality was found with increasing sedimentation rates. Soils in plots with the highest sedimentation rates (highly disturbed or HD) exhibited decreased CEC, temperature, and moisture, and increased bulk density, sand content, and pH. The HD plots also had lower nutrient turnover from decomposition, net N mineralization rates, and microbial C and N. Declines in biogeochemical processes corresponded to sedimentation rates associated with HD plots (1.0 cm yr−1). Shifts in biological indicators corresponding to annual variations in climate suggest that the stress of sedimentation may be further exacerbated by drought conditions. The results of this study imply that even low levels of erosional deposition in headwater riparian forests may significantly impact biogeochemical processes in these systems.
Effects of Irrigation with Different Effluents on Saturated Hydraulic Conductivity of Arid and semiarid Soils
Authors: Lado Marcos , Ben-Hur Meni
Published: January 2010

The use of recycled wastewater that has undergone various treatments (effluent) for irrigation is becoming one of the main means by which to mitigate the pressure on freshwater resources. The main objective of this study was to improve the basic understanding of the effects of irrigation with various effluents on the saturated hydraulic conductivity (Ks) of arid and semiarid soils. Clay, loamy, and sandy soils were sampled from experimental plots irrigated with freshwater or secondary effluent for >3 yr, and were used in column experiments. Leaching the loamy and clay soils with reverse osmosis (RO) effluent, which contained low electrolyte concentrations, led to clay swelling and dispersion and thereby decreased the soil Ks In these soils, the high concentration of suspended solid particles and dissolved organic matter (DOM) in oxidation pond (OP) effluent caused significant pore clogging, which reduced the Ks Leaching the soils with ultrafiltered effluent maintained high Ks values due to the low concentration of suspended solid particles and DOM, their small sizes, and the relatively high electrical conductivity of this effluent. The relatively large average pore size in the sandy soil prevented pore clogging and Ks reduction when leached with RO and OP effluent. Secondary effluent irrigation increased the soil exchangeable Na percentage (ESP) compared with freshwater irrigation but did not change the organic matter content in the soil. In the loamy and clay soils, this higher ESP of the effluent‐irrigated soils resulted in greater reductions in Ks when leached with deionized water than occurred in freshwater‐irrigated soils.
Rapid One‐Step Method for Total Fatty Acids in Soils and Sediments
Authors: Graber Ellen R. , Tsechansky Ludmila
Published: January 2010

In this study, a method was developed to extract and methylate total fatty acids (TFA) from soils and sediments using an acid‐catalyzed esterification–transesterification approach; the TFA method was compared with other methods in common use for fatty acids in soils. The developed method was significantly more successful in the extraction and methylation of total soil and sediment fatty acids than other methods. It also extracted long‐chain hydrocarbons from soils and sediments. The TFA method is relatively simple and rapid, has high reproducibility, substantially reduced solvent use, and can easily accommodate a large number of samples at the same time. The optimized TFA method is based on a combined “one‐step” acid‐catalyzed approach often used for biological tissues, oils, feedstuff, and leafy materials. Acid‐catalyzed methylation is effective under many conditions, and methylates all fatty acids, including free fatty acids, fatty acid esters and amides, and fatty acid salts via both esterification and transesterification pathways. Used in conjunction with other methods, the TFA method can help to provide information about the distribution of ester‐linked fatty acids and free fatty acids or fatty acid salts in soils and sediments.
Effect of Temperature on Potassium and Sodium Exchange in a Sierra Nevada Riparian Soil
Authors: Blank Robert R.
Published: January 2010

In the course of investigating nutrient availability in a montane meadow ecosystem of the Sierra Nevada range, it was determined that resin availability of Na+and K+was significantly affected by season (winter vs. summer and fall). The underlying mechanism(s) controlling this seasonal effect was investigated in the laboratory. Four replicate A horizon samples of a Typic Humaquept (silty clay texture, kaolinitic mineralogy, 3% organic C, pH 5.10) were saturated with Mg2+Using 5‐g subsamples from each replicate, soil was equilibrated for a period of 30 min with 30 mL of a 5.00 mmol solution of Na+and K+at 1, 15, 30, and 45°C. After centrifugation, the supernatant was analyzed for K+, Na+, and Mg2+Exchanger sorption characteristics varied significantly with temperature. Overall, K+was preferentially sorbed over Na+, but the proportional sorption of K+decreased significantly at a temperature of 1°C. The temperature dependence of K+and Na+sorption partially explains seasonal differences in availability. Net sorption (K++ Na+− Mg2+) was statistically similar to 0 at temperatures of 15, 30, and 50°C, but significantly increased at 1°C. This increase in cation exchange capacity at low temperature may have special relevance to ecosystems during snowmelt when increased retention of certain cations could occur.
Hydra Probe and Twelve‐Wire Probe Comparisons in Fluids and Soil Cores
Authors: Logsdon S. D. , Green T. R. , Seyfried M. , Evett S. R. , Bonta J.
Published: January 2010

Soil water content is often determined using various permittivity sensors. The Hydra Probe reports both the real (ε′) and imaginary (ε″) components of complex permittivity (ε*) and estimates electrical conductivity (σ′). Previously, a 12‐wire probe was used with a vector network analyzer to determine ε′ and ε″ and σ′ and σ″ in undisturbed soil cores. The purpose of this study was to compare results from the Hydra Probe and the 12‐wire probe for fluids as well as for soil samples taken from six locations, to better understand the interrelations of ε′, ε″, and σ′ from the Hydra Probe. Undisturbed soil cores were collected from an Iowa prairie and adjacent soybean [Glycine max(L.) Merr.] field, an Iowa forest and adjacent soybean field, Idaho burned and unburned sites, Colorado grassland and dryland wheat (Triticum aestivumL.) sites, Ohio grassed areas, and Texas rangeland and an irrigated field. Because of their density, some of the Texas samples were sieved and repacked. The reported σ′, ε′, and ε″ values of fluids were compared between the two measurement systems and with theoretical values. Because the theoretical values for soils are not known, the measured values were compared between systems. Both probes showed σ′, ε′, and ε″ close to the theoretical values for fluids. In soils, we showed that an adjustment was needed in the calculated σ′ from the Hydra Probe to account for dielectric relaxation. The soil σ′ of the Hydra Probe matched σ′ from the 12‐wire probe better after the adjustment was made.
Hydroxyproline Levels in Young Adults Undergoing Muscular Stretching and Neural Mobilization
Authors: da Rocha Mafra Olivia , da Silva Elirez , Giani Tania , Neves Carlos , Lopes Rauena , Dantas Estélio
Published: January 2010

Hydroxyproline Levels in Young Adults Undergoing Muscular Stretching and Neural Mobilization

This study aimed to assess the acute effect of stretching and neural mobilization on urinary hydroxyproline (HP) levels in young adults. The sample, composed of physical therapy students from Teresina (PI), was divided into three groups: a neural mobilization group (NMG; n=15; age=22±3 years; BMI=24.75±3.09); a static stretching group (SSG; n=15; age=23±4 years; BMI: 25±4.33) and a control group (CG; n=15; age: 24±4 years; BMI: 23.91±3.09). The NMG underwent neural mobilization of the sciatic nerve while engaged in hip flexion with knee extension in a direct, oscillatory and strenuous manner for 60 seconds. The SSG performed passive static stretching, which consisted of the maintenance of a high amplitude posture, without exceeding the limits of the movement, for a period of tension ranging from four to six seconds. Urinary HP was evaluated at the baseline and 24 hours after the intervention using the colorimetric method. Repeated measures ANOVA showed significant intragroup increases in the NMG (Δ7.38 mg/24h; p=0.0001) and the SSG (Δ=3.47 mg/24h; p=0.002) and inter-group increases in the NMG (Δ%=118.89%) when compared to the SSG (Δ%=60.32%; p=0.006) and the CG (Δ%=-0.91%; p=0.0001). These results indicate that the NMG worked with tension beyond the ordinary amplitude arches of articular movement, thus causing a restructuring of collagen.
Urinary Activities of Proximal Tubule Enzymes in Neonates Treated with Gentamicin
Authors: Davidović-Plavšić Biljana , Vujić Tatjana , Uletilović Snežana , Predojević-Samardžić Jelica , Malčić Dragana , Saničanin Živko
Published: January 2010

Urinary Activities of Proximal Tubule Enzymes in Neonates Treated with Gentamicin

In order to determine the nephrotoxicity of gentamicin, an aminoglycoside antibiotic, activity of the enzymes dominantly localized in proximal tubules, i.e. alanine aminopeptidase (AAP), γ-glutamyl transferase (GGT) and N-acetylβ-D-glucosaminidase (NAG) was examined. Determinations were performed in 12-h urine samples of 30 neonates i.v. receiving gentamicin against Gram negative infections in daily doses of 5.0 mg/kg body mass for 10 consecutive days. The activities of the same enzymes were measured in 12-h urine samples of 30 examinées of the control group. The groups consisted of neonates of both sexes. The pretreatment period lasted for 5 days. On day 8 of gentamicin application, statistically significant differences in the activity of AAP and GGT expressed in U/mmol creatinine between the gentamicin-receiving and control group (p<0.01) were found. No significant differences in NAG activity of the gentamicin-treated group in comparison with the control were recorded during the 10-day gentamicin therapy. It can be concluded that 10-day treatment of neonates with usually prescribed gentamicin doses results in mild nephrotoxic changes close to the end of the therapy accompanied by increased activity of both urinary AAP and GGT, known as very sensitive indicators of nephrotoxicity. During the same treatment period no changes in NAG activity were observed, meaning that the antibiotic causes no severe injuries to proximal tubule cells at the level of cellular organelles.
The Change of Ghrelin Levels in Intestinal Parasitic Infections
Authors: Erensoy Ahmet , Aydin Suleyman , Kelestimur Neslihan , Kirbag Sevda , Kuk Salih
Published: January 2010

The Change of Ghrelin Levels in Intestinal Parasitic Infections

The aim of this work was to examine the relationship between active (acylated ghrelin) and inactive (desacylated ghrelin) ghrelin in the serum and other serum parameters in intestinal parasitic infections and healthy controls. Conventional microscopic methods (saline and iodine solutions, trichrome stain) were used to identify intestinal parasites in stool samples of 29 subjects attending Firat University Hospital. Serum parameters were assessed in a single measurement of serum from 29 parasite subjects, and in 18 healthy controls. Serum acylated ghrelin and desacylated ghrelin levels were measured using a commercial radioimmunoassay (RIA) kit. Paraoxonase and arylesterase were measured by using a spectrophotometer at 405 nm and 270 nm, respectively. Serum concentrations of acylated ghrelin and desacylated ghrelin were more markedly decreased in helminth bearing patients than the control group. Glucose, cholesterol and triglyceride levels were higher in intestinal parasitic infections than in controls. Furthermore, there were no correlations between ghrelin levels and BMI. These results indicate that low ghrelin and PON1/AE level may be important for appetite monitoring in intestinal parasitic infections.
Histopathology and cholinergic assessment of Pterocarya fraxinifolia on chicken embryo
Authors: Sadighara Parisa , Ashrafihelan Javad , Barin Abbas , Esfahani Tahreh
Published: January 2010

Histopathology and cholinergic assessment ofPterocarya fraxinifoliaon chicken embryo

There are no reports of toxicological studies ofPterocarya fraxinifolia.The leaves are used for fishing, which also an anesthetic agent. Currently, many drugs utilized in anesthesia practice are modified cholinergic transmission and acetylcholine esterase inhibitors; these are parts of anaesthetic pharmacy. Therefore, cholinergic assessment was surveyed in chicken embryo, whichPterocarya fraxinifoliaextractes were injected in 0.1, 1 and 10 mg concentration at day 4 of incubation. Serum and brain cholinesterase were analyzed on day 20 of incubation. The signs were not due to the changes of cholinesterase activity. In histopathology examination, massive necrosis was observed in the spinal cord. Other tissues such as heart, kidneys, skeletal bones and muscles, trachea and lungs, digestive system and endocrine glands were completely developed. This data suggests that the spinal cord is a target organ of the bioactive component of this plant.
Faculty Ethics: Ideal Principles with Practical Applications
Authors: Reybold L. Earle
Published: January 2010

Ethics in higher education is the subject of intense public attention, with considerable focus on faculty roles and responsibilities. Media reports and scholarly research have documented egregious misconduct that includes plagiarism, falsification of data, illicit teacher–student relationships, and grading bias. These accounts of wrongdoing often portray faculty ethicality as only a legal issue of obeying rules and regulations, especially in the teaching and research roles. My discussion challenges this narrow perspective and argues that characterizations of faculty ethicality should take into account broader expectations for professionalism such as collegiality, respect, and freedom of inquiry. First, I review the general principles of faculty ethics developed by the American Association of University Professors, as well as professional codes of ethics in specific professional fields. Second, I juxtapose the experiences of women and minority faculty members in relation to these general codes of ethics. This section examines three issues that particularly affect women and minority faculty experiences of ethicality: “chilly and alienating” academic climates, “cultural taxation” of minority identity, and the snare of conventional reward systems. Third, I suggest practical strategies to reconcile faculty practice with codes of ethics. My challenge is to the faculty as a community of practice to engage professional ethics as social and political events, not just legal and moral failures.