A global experiment under way     

da Fonseca GA  Gascon C  Steininger MK  Brooks T  Mittermeier RA  Lacher TE 《Science (New York, N.Y.)》2002,295(5561):1835

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Ecology. Receding forest edges and vanishing reserves     

Gascon C  Williamson GB  da Fonseca GA 《Science (New York, N.Y.)》2000,288(5470):1356-1358

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Thermally Switchable Periodicities and Diffraction from Mesoscopically Ordered Materials     

JM Weissman  HB Sunkara  AS Tse  SA Asher 《Science (New York, N.Y.)》1996,274(5289):959-960

Two switchable, mesoscopically periodic materials were created by combining crystalline colloidal array (CCA) self-assembly with the temperature-induced volume phase transition of poly(N-isopropylacrylamide) (PNIPAM). Body-centered-cubic CCAs of hydrated, swollen PNIPAM particles Bragg-diffract infrared, visible, and ultraviolet light weakly, whereas arrays of compact shrunken particles diffract efficiently. A tunable diffracting array was also created by embedding a CCA of polystyrene spheres within a PNIPAM hydrogel that swells and contracts with temperature; thus the array lattice constant varies with temperature, and the diffracted wavelength was thermally tunable across the entire visible spectrum. These materials may find applications in many areas of optics and materials science.  相似文献   

Clinical trial of efficacy of ivermectin pour‐on against gastrointestinal parasitic nematodes in silvopasturing horses     

I. FRANCISCO  J. A. SÁNCHEZ  F. J. CORTIÑAS  R. FRANCISCO  E. MOCHALES  M. ARIAS  P. MULA  J. L. SUÁREZ  P. MORRONDO  P. DÍEZ‐BAÑOS  R. SÁNCHEZ‐ANDRADE  A. PAZ‐SILVA 《Equine veterinary journal》2009,41(7):713-715

The aim of this study was to assess, by a clinical trial, the efficacy of an ivermectin‐based pour‐on treatment against gastrointestinal parasitic nematodes in naturally infected horses using 2 groups of mature indigenous Pura Raza Galega grazing mares. Faecal and blood samples were collected individually over a 21 week period. Faeces were analysed by the coprological flotation, sedimentation and migration techniques. Changes in circulating blood cells were monitored over the study period. The administration of the ivermectin suppressed the eggelimination of ascarids and pinworms throughout the study and no strongyle‐eggs were observed in the treatment group between the 3rd and 10th weeks. The numbers of red cells increased significantly after the anthelmintic therapy, and a statistical reduction in circulating leucocytes was recorded. No side effects were observed. The pour‐on ivermectin formulation was highly successful against gastrointestinal nematodes and appears to be a useful therapeutic routine for large groups of horses.  相似文献   

Genetic parameters for loin eye area and other body traits of an important Neotropical aquaculture species,Colossoma macropomum (Cuvier, 1818)     

Caio Augusto Perazza  Jos Bento Sterman Ferraz  Vera Maria Fonseca Almeida‐Val  Alexandre Wagner Silva Hilsdorf 《Aquaculture Research》2019,50(10):2907-2916

Estimating components of variance and genetic parameters of economically relevant traits is the first step towards planning a breeding program for aquaculture species. This study estimated the (co)variance components for growth rate and other body traits and then determined a multiple regression equation to assess the loin eye area (LEA) from morphometric traits of the Neotropical aquaculture species Colossoma macropomum. Estimation of variance components was performed using derivative‐free restricted maximum likelihood estimation using the MTDFREML package. Six predictive variables were tested to estimate the coefficient of regression equation and to select the most suitable model for predicting LEA. The estimated genetic parameter for body weight showed moderate‐to‐high heritability estimates of 0.26 (0.01) and 0.49 (0.01) at 221 and 623 days respectively. The genetic correlation (r_g) estimates between body size measurements were positive and ranged from low to high at both ages. The heritability for LEA in this assessment was 0.39 (0.03). The genetic and phenotypic correlations between LEA and the other body measurements ranged from 0.16 to 0.94 and 0.75 and 0.90 respectively. The outcomes of this study can contribute to the development of a genetics‐based breeding program that will improve (tambaqui) productivity and carcass quality.  相似文献   

Technical and economic feasibility of integrating seahorse culture in shrimp/oyster farms          下载免费PDF全文

Tamara Fonseca  Fernanda S David  Felipe A S Ribeiro  Alexandre A Wainberg  Wagner C Valenti 《Aquaculture Research》2017,48(2):655-664

Integrated multi‐trophic aquaculture systems (IMTA) are building ecosystems designed to produce aquatic organisms with less environmental impact. We have developed a simple system and a management strategy for introducing seahorse (Hippocampus spp.) culture in shrimp/oyster farms to increase economic sustainability. The system includes broodstock, nursery and grow‐out phases of Hippocampus reidi G. culture. We performed a test in a 42.4‐ha marine shrimp/oyster farm, which showed that this system is technically feasible. Then, we performed a partial budget analysis including cost‐return, cash flow and financial feasibility analysis. More than 12 000 marketable size seahorses may be produced in 402 m² annually. Initial investment was only US$ 21 103.00. The benefit–cost ratio was ~US$ 20.00 for each US$ 1.00 spent, internal rate of return was 131% and payback period <2 years. In conclusion, the introduction of seahorse in shrimp/oyster IMTA system is technically feasible, profitable, resilient and shows high liquidity. This system may be easily established in developing countries and has potential to provide seahorses to supply different markets (live specimens for the marine aquarium trade and dried specimens for traditional Chinese medicine and the curio trade). In addition, it can indirectly contribute to preserve natural populations.  相似文献   

Carbon and nitrogen cycling in a tropical Brazilian soil cropped with sugarcane and irrigated with wastewater   总被引：1，自引：0，他引：1  

Rafael Marques Pereira Leal  Lilian Pittol Firme  Adriel Ferreira da Fonseca  Carlos Tadeu dos Santos Dias 《Agricultural Water Management》2010,97(2):271-276

Carbon (C) and nitrogen (N) dynamics in agro-systems can be altered as a consequence of treated sewage effluent (TSE) irrigation. The present study evaluated the effects of TSE irrigation over 16 months on N concentrations in sugarcane (leaves, stalks and juice), total soil carbon (TC), total soil nitrogen (TN), NO₃⁻-N in soil and nitrate (NO₃⁻) and dissolved organic carbon (DOC) in soil solution. The soil was classified as an Oxisol and samplings were carried out during the first productive crop cycle, from February 2005 (before planting) to September 2006 (after sugarcane harvest and 16 months of TSE irrigation). The experiment was arranged in a complete block design with five treatments and four replicates. Irrigated plots received 50% of the recommended mineral N fertilization and 100% (T100), 125% (T125), 150% (T150) and 200% (T200) of crop water demand. No mineral N and irrigation were applied to the control plots. TSE irrigation enhanced sugarcane yield but resulted in total-N inputs (804-1622 kg N ha⁻¹) greater than exported N (463-597 kg N ha⁻¹). Hence, throughout the irrigation period, high NO₃⁻ concentrations (up to 388 mg L⁻¹ at T200) and DOC (up to 142 mg L⁻¹ at T100) were measured in soil solution below the root zone, indicating the potential of groundwater contamination. TSE irrigation did not change soil TC and TN.  相似文献