Measurement of tear production in black‐tufted marmosets (Callithrix penicillata) using three different methods: modified Schirmer’s I,phenol red thread and standardized endodontic absorbent paper points     

Rogério R. Lange  Leandro Lima  Fabiano Montiani‐Ferreira 《Veterinary ophthalmology》2012,15(6):376-382

Objective: To report normal tear production of healthy adult black‐tufted marmosets and propose a novel alternative for the measurement of the aqueous portion of tear production in animals with small eyes. Animal studied: Black‐tufted marmosets (Callithrix penicillata). Procedures: Tear production of 19 animals was evaluated by the following methods: modified Schirmer’s I, phenol red thread and the novel use of standardized endodontic absorbent paper points. These methods and results were compared. Additionally, blink frequency and palpebral fissure length were measured. Results: Modified Schirmer’s test I, mean = ?0.46 ± 3.41 mm/min; Phenol red thread, mean = 13.27 ± 5.41 mm/15 s.; Standardized endodontic paper points, size 30, mean = 9.32 ± 3.09 mm/min; Mean palpebral fissure length = 7.83 ± 0.72 mm. Blink frequency, mean = 20.27 ± 5.92/5 min. Conclusions: Normal parameters for blink frequency, palpebral fissure length and tear production measurement are presented. The palpebral fissure of black‐tufted marmoset is very small and tear production is one of the lowest reported for all animal species. A novel and practical alternative for tear production measurement using standardized endodontic absorbent paper points is presented and is indicated for animals with small eyes.  相似文献   

Assessment of field fertility and several in vitro sperm characteristics following the use of different Angus sires in a timed-AI program with suckled Nelore cows     

Letícia Zoccolaro Oliveira  Rubens Paes de Arruda  André Furugen Cesar de Andrade  Eneiva Carla Carvalho Celeghini  Ricarda Maria dos Santos  Marcelo Emílio Beletti  Rogério Fonseca Guimarães Peres  Clara Slade Oliveira  Vera Fernanda Martins Hossepian de Lima 《Livestock Science》2012,146(1):38-46

In order to provide information that may help researchers to understand the main cause(s) of differences in bull fertility frequently observed in field trials, this study aimed to investigate conception rates as well as several in vitro sperm characteristics of different sires of unknown fertility utilized in a Timed-AI (TAI) program. Suckled Nelore cows submitted to the same TAI protocol were allocated into eight breeding groups of approximately 120 animals each. Frozen semen doses from three Angus bulls and three different batches from each bull were utilized. Approximately 100 doses from each batch were used in TAI. Sires, batches and AI technicians were equally distributed across breeding groups. Cows were examined for pregnancy diagnosis 40 d after TAI. For in vitro sperm analyses, the same thawing procedure was repeated in the laboratory to mimic field conditions. The following in vitro sperm characteristics were assessed: computerized motility, thermal resistance, plasma and acrosomal membrane integrity, lipid peroxidation, morphology, morphometry and chromatin structure. No effect of breeding group, body condition score, AI technician and sire was observed. However, some significant differences among bulls were detected in laboratory analyses. Semen from sire presenting numerically lower (P > 0.05) pregnancy/AI also presented lower (P < 0.05) values in all sperm characteristics analyzed in thermal resistance test at 4 h (Total Motility, Progressive Motility, Average Path Velocity, Straight-Line Velocity, Curvilinear Velocity, Amplitude of Lateral Head Displacement, Beat Cross Frequency, Straightness, Linearity, and Percentage of Rapidly Moving Cells), higher (P < 0.05) Major and Total Defects in sperm morphological test, lower (P < 0.05) Length, Ellipticity and Fourier parameter (Fourier 0) in sperm morphometric analysis as well as higher (P < 0.05) chromatin heterogeneity. It was concluded that, although no bull effect was observed in the field experiment, the sire that presented numerically lower pregnancy/AI also presented lower semen quality according to the laboratory analyses performed.  相似文献   

Partitioning carbon fluxes in a Mediterranean oak forest to disentangle changes in ecosystem sink strength during drought     

Stephan Unger  Cristina Máguas  João S. Pereira  Luis M. Aires  Teresa S. David  Christiane Werner 《Agricultural and Forest Meteorology》2009,149(6-7):949-961

Net carbon flux partitioning was used to disentangle abiotic and biotic drivers of all important component fluxes influencing the overall sink strength of a Mediterranean ecosystem during a rapid spring to summer transition. Between May and June 2006 we analyzed how seasonal drought affected ecosystem assimilation and respiration fluxes in an evergreen oak woodland and attributed variations in the component fluxes (trees, understory, soil microorganisms and roots) to observations at the ecosystem scale. We observed a two thirds decrease in both ecosystem carbon assimilation and respiration (R_eco) within only 15 days time. The impact of decreasing R_eco on the ecosystem carbon balance was smaller than the impact of decreasing primary productivity. Flux partitioning of GPP and R_eco into their component fluxes from trees, understory, soil microorganisms and roots showed that declining ecosystem sink strength was due to a large drought and temperature-induced decrease in understory carbon uptake (from 56% to 21%). Hence, the shallow-rooted annuals mainly composing the understory have a surprisingly large impact on the source/sink behavior of this open evergreen oak woodland during spring to summer transition and the timing of the onset of drought might have a large effect on the annual carbon budget. In response to seasonal drought R_eco was increasingly dominated by respiration of heterotrophic soil microorganisms, while the root flux was found to be of minor importance. Soil respiration flux decreased with drought but its contribution to total daily CO₂-exchange increased by 11.5%. This partitioning approach disentangled changes in respiratory and photosynthetic ecosystem fluxes that were not apparent from the eddy-covariance or the soil respiration data alone. By the novel combination of understory vs. overstory carbon flux partitioning with soil respiration data from trenched and control plots, we gained a detailed understanding of factors controlling net carbon exchange of Mediterranean ecosystems.  相似文献   

Role of rock fragment cover on runoff generation and sediment yield in tilled vineyards          下载免费PDF全文

J. Rodrigo‐Comino  A. García‐Díaz  E. C. Brevik  S. D. Keestra  P. Pereira  A. Novara  A. Jordán  A. Cerdà 《European Journal of Soil Science》2017,68(6):864-872

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Ultrasonic Aggregate Breakdown of an Oxisol as Affected by Cavitation Intensity     

Bruno Teixeira Ribeiro  José Maria de Lima  Nilton Curi  Geraldo César de Oliveira  Érika Andressa da Silva  Bruno Montoani Silva 《Communications in Soil Science and Plant Analysis》2017,48(7):818-824

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Effect of Nitrogen and Potassium Fertilization on Banana Plants Cultivated in the Humid Tropical Amazon     

M. M. J. Fratoni  L. A. C. Moraes  L. H. C. Almeida  J. C. R. Pereira 《Communications in Soil Science and Plant Analysis》2017,48(13):1511-1519

Banana (Musa spp.) is widely cultivated in tropical regions because of their economic importance for the local market as the source of food for the regional population. In the Amazon region, the banana crop was cultivated in the river basin before the 90th decade of the last century, but after the black sigatoka (Mycosphaerella fijiensis) and the increases of the bacteria wilt (Raostonia solanarum), the crops migrated to upper land soils with low natural fertility where there was no influence of floods for natural fertilization from the regional rivers. Nitrogen (N) and potassium (K) have been the foremost nutrient required by the banana trees and the aim of this study was to evaluate during two growing periods, the influence of the N and dipotassium oxide (K₂O) fertilization in yield and nutritional status of banana. The experimental design was a completely randomized blocks in a factorial 3 × 4 scheme with three replicates. The treatments were three N rates (0, 267, and 533 kg ha^?1) and four K₂O rates (200, 800, 1,600, and 2,400 kg ha^?1). The field plots had seven plants where the useful area had only five plants spaced 3 m × 2 m. The foliar N and sulfur (S) content were significantly influenced by the N rates, while foliar K, magnesium (Mg), and copper (Cu) were significant under the K₂O rates. The N, K₂O, and N × K₂O interaction interfered the foliar zinc (Zn) content. In both crop cycles, the bunch biomass and banana yield were not influenced by the N and K₂O rates.  相似文献   

Soil Contamination by Toxic Metals Near an Antarctic Refuge in Robert Island,Maritime Antarctica: A Monitoring Strategy     

Elias de Lima Neto  Marcelo Braga Bueno Guerra  André Thomazini  Mayara Daher  André Medeiros de Andrade  Carlos Ernesto G. R. Schaefer 《Water, air, and soil pollution》2017,228(2):66

The anthropogenic effects of Antarctic refuge buildings and research stations on the surrounding soils are scarcely investigated, especially when the structures are small-sized, and sporadically used or visited. The Coppermine Peninsula (Robert Island, South Shetland Islands archipelago) possesses one of the richest flora in Antarctica, being classified as an Antarctic Specially Protected Area (ASPA). There, a small refuge (Luis Risopatrón) has been seasonally occupied for scientific purposes since 1957, although no studies on the anthropic disturbances in the surroundings soils are reported. The aim of this study was the determination of the potentially toxic metals (Cd, Cr, Cu, Mn, Ni, Pb, V, and Zn) mass fractions in surface soils (n?=?40) collected at the surroundings of the Luis Risopatrón refuge. Enrichment factors (EF) and geoaccumulation index (I _geo) were also calculated, using Zr as the reference element, in order to evaluate the anthropogenic impacts of these small buildings in the studied area. The main contaminants were Pb and Zn, which presented EF and I _geo values ranging from 1.0 to 18.3 and from ?1.8 to 3.5. The mass fractions of these elements determined after an aqua regia extraction varied from 5.4 to 102 mg kg^?1 Pb and from 43 to 210 mg kg^?1 Zn. These results highlight that a small refuge can show environmental disturbance from low to moderate, with few hotspots with heavily contaminated soils. Environmental monitoring strategy for similar refuges anywhere in Antarctica is recommended.  相似文献   

Low Concentrations of Glyphosate-Based Herbicide Affects the Development of <Emphasis Type="Italic">Chironomus xanthus</Emphasis>     

Diogenis F. Ferreira-Junior  Renato Almeida Sarmento  Althiéris de Souza Saraiva  Renata Ramos Pereira  Marcelo Coutinho Picanço  João L. T. Pestana  Amadeu M.V.M. Soares 《Water, air, and soil pollution》2017,228(10):390

Glyphosate is an herbicide commonly used worldwide for weed control and generally applied as part of a formulated product, such as Roundup. Contamination of surface water by glyphosate-based herbicides can cause deleterious effects in organisms, mainly in aquatic systems near to intensive agricultural areas (e.g., transgenic soybean crops). Given the lack of toxicological information concerning effects of glyphosate-based herbicides on tropical aquatic ecosystems, we aimed to evaluate the lethal and sub-lethal effects of Roundup Original® on the dipteran Chironomus xanthus. The endpoints evaluated included survival, growth, and emergence. The results showed that the 48 h LC₅₀ for glyphosate to C. xanthus was 251.5 mg a.e./L. Larval growth of C. xanthus was reduced under glyphosate exposure (LOEC for body length = 12.06 mg/L; LOEC for head capsule width = 0.49 mg/L). No effects were observed in terms of cumulative percentage of imagoes emergence. However, low concentrations of glyphosate caused delayed emergence of females (at 1.53 mg/L) and induced fast emergence of males (at 0.49 mg/L), compared to control treatment. The deleterious effects of environmental relevant concentrations of glyphosate (0.7 mg/L) observed in terms of C. xanthus growth and development suggest that glyphosate-based herbicides can have negative consequences for aquatic non-target invertebrates such as Chironomus. Multigerational assays are needed to assess the long term effects of glyphosate on C. xanthus populations. Finally, our study adds ecotoxicological data on the effects of glyphosate-based herbicides on tropical freshwater invertebrates.  相似文献   

Nitrogen in plant growth and yield of common bean     

Vinícius Toso  Jerônimo Luiz Andriolo  Maíne Alessandra Lerner  Odair José Schmitt  Francieli Lima Cardoso 《Journal of plant nutrition》2017,40(14):2006-2013

The aim of this research was to determine the effect of nitrogen (N) availability on wild Rhizobiumnodulation, plant growth and grain yield of the common bean crop. Experiments were conducted in two growing periods, from 2 March to 3 June 2011 (autumn) and from 21 September to 23 December 2011 (spring), in pots using sand as substrate. Nitrogen concentrations of 5.12 (T1), 7.6 (T2), 10.12 (T3), 12.62 (T4), and 15.12 (T5) mmol L^?1 were supplied by fertigation. In spring, the grain yield, number of grains and shoot growth of both cultivars reduced by effect of N concentration but in the cultivar BRS Valente they reducedonly in autumn. Number of nodules and root growth decreased in both cultivars while N concentration increased in the plant tissues. Nitrogen fertilization is not required to the common bean and its use inhibits nodulation. The increased availability does not enhance plant growth and grain yield.  相似文献   

NDVI variation according to the time of measurement,sampling size,positioning of sensor and water regime in different soybean cultivars     

Luis?Guilherme?Teixeira?Crusiol  Josirley?de?Fátima?Corrêa?Carvalho  Rubson?Natal?Ribeiro?Sibaldelli  Walkyria?Neiverth  Alexandre?do?Rio  Leonardo?Cesar?Ferreira  Sergio?de?Oliveira?Procópio  Liliane?Márcia?Mertz-Henning  Alexandre?Lima?Nepomuceno  Norman?Neumaier  José?Renato?Bou?as?FariasEmail author 《Precision Agriculture》2017,18(4):470-490

Although the information on the Normalized Difference Vegetation Index (NDVI) in plants under water deficit is often obtained from sensors attached to satellites, the increasing data acquisition with portable sensors has wide applicability in agricultural production because it is a fast, nondestructive method, and is less prone to interference problems. Thus, we carried out a set of experiments to investigate the influence of time, spatial plant arrangements, sampling size, height of the sensor and water regimes on NDVI readings in different soybean cultivars in greenhouse and field trials during the crop seasons 2011/12, 2012/13 and 2013/14. In experiments where plants were always evaluated under well-watered conditions, we observed that 9 a.m. was the most suitable time for NDVI readings regardless of the soybean cultivar, spatial arrangement or environment. Furthermore, there was no difference among NDVI readings in relation to the sampling size, regardless of the date or cultivar. We also observed that NDVI tended to decrease according to the higher height of the sensor in relation to the canopy top, with higher values tending to be at 0.8 m, but with no significant difference relative to 1.0 m—the height we adopted in our experiments. When different water regimes were induced under field conditions, NDVI readings measured at 9 a.m. by using a portable sensor were successful to differentiate soybean cultivars with contrasting responses to drought.  相似文献