Seroprevalence study of bovine neosporosis in Mexico.     

E Morales  F J Trigo  F Ibarra  E Puente  M Santacruz 《Journal of veterinary diagnostic investigation》2001,13(5):413-415

An indirect enzyme-linked immunosorbent assay was used to obtain epidemiologic information on bovine neosporosis in dairy herds of the Mexican central plateau. Sera were collected from 1,003 cows from 50 dairy herds. Forty-three herds (group A) had been experiencing a high abortion rate. The abortion rates for the remaining 7 herds (group B) were within normal limits for Mexico. Five-hundred sixty-one (56%) of the 1,003 sera were positive. The seroprevalence of Neospora caninum antibodies was 72% (95% CI = 68-75%) in group A and 36% (95% CI = 31-40%) in group B. These results clearly show that infection with N. caninum is widespread in Mexican dairy herds, as indicated by seropositive cows in group A and group B herds at the time of the sample collection.  相似文献   

Pest Management in Traditional Tropical Agroecosystems: Lessons for Pest Prevention Research and Extension   总被引：1，自引：0，他引：1  

Helda Morales 《Integrated Pest Management Reviews》2002,7(3):145-163

Based on current agroecological theory and IPM practices, this review explores the role of traditional practices, involving site selection, soil management, timing of planting and harvesting, crop resistance, intercropping, weed management, harvest residue management, post-harvest management, natural enemies management, mechanical control, repellents and traps in the natural regulation of potential pests. In synthesis, the literature suggests that although pest management professionals focus their efforts on pest control, the preventative approach taken by traditional farmers is more effective. Potential constraints to the implementation of this preventive pest management approach include:(1) lack of integration of ecological theory and pest management, (2) lack of cooperation among social and biological scientists, and (3) lack of real efforts to work with farmers as equals and support mechanisms that protect their knowledge. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Geographical cline of DNA variation within the F intersterility group of Heterobasidion annosum in Italy     

N. LA PORTA  P. CAPRETTI  K. KAMMIOVIRTA  R. KARJALAINEN  & K. KORHONEN 《Plant pathology》1997,46(5):773-784

Eighty-six Heterobasidion annosum isolates, mainly belonging to the F intersterility group and obtained from 32 different geographical localities in Italy, were subjected to genetic analysis by the Random Amplified Polymorphic DNA (RAPD) markers. The similarity between F and S groups was higher than that between F and P. In UPGMA Cluster Analysis, the F isolates originating from the same locality usually grouped in the same cluster. The isolates also showed a tendency to group at the level of larger geographical areas. Within the F group, isolates from the south of the Italian peninsula showed the highest genetic variation and northern isolates from the Alpine regions showed the lowest. This indicates a gradual cline along the peninsula. The genetic variability in the Italian F group is discussed in relation to the past and present distribution of the host species in Italy and Europe.  相似文献   

Laryngeal mask airway and transient hypercapnic hyperpnea for video‐endoscopic assessment of unilateral laryngeal paralysis in dogs          下载免费PDF全文

Daniel M. Sakai MV  DACVAA  Manuel Martin‐Flores MV  DACVAA  Amanda K. Jones PhD  Galina M. Hayes BVSc  PhD  DACVECC  DACVS‐SA  Marina J. McConkey DVM  DACVS‐SA  Jonathan Cheetham VetMB  PhD  DACVS‐LA 《Veterinary surgery : VS》2018,47(4):543-548

  相似文献   

Effect of feed intake level and dietary protein content on the body temperature of pigs housed under thermo neutral conditions          下载免费PDF全文

A. Morales  N. Ibarra  M. Chávez  T. Gómez  A. Suárez  J. A. Valle  R. L. Camacho  M. Cervantes 《Journal of animal physiology and animal nutrition》2018,102(2):e718-e725

Feed intake and diet composition appear to affect the body temperature of pigs. Two trials were conducted to analyse the effect of feed intake level and dietary protein content on the intestinal temperature (IT) of pigs housed under thermo neutral conditions. Ten pigs (64.1 ± 1.3 kg initial body weight) fitted with an ileal cannula were used. A thermometer set to register the IT at 5‐min intervals was implanted into the ileum through the cannula. In both trials, the ambient temperature ranged from 19.1 to 21.6°C and the pigs were fed at 07:00 and 19:00 hr (same amount each time). In trial 1, the pigs were fed daily 1.2 or 1.8 kg of a wheat–soybean meal diet. The IT followed a similar pattern along a 24‐hr period regardless the feed intake level. The IT rapidly increased up to 0.61 and 0.74°C after the morning meal and up to 0.53 and 0.47°C after the evening meal in pigs fed 1.2 and 1.8 kg/d respectively. The postprandial IT was higher in pigs fed 1.8 kg after each meal (p < .05). In trial 2, pigs were fed daily 1.8 kg of a low (11%) or a high (22%) crude protein diet. The IT followed a similar pattern along the 24‐hr period regardless the dietary protein level. The postprandial IT did not differ between pigs fed the low protein or the high protein (p > .10). The IT rapidly increased up to 0.66 and 0.62°C after the morning meal in pigs fed the high‐ and low‐protein diet (p < .05), but there was no change after the evening meal (p > .10). In conclusion, the feed intake level affected the IT of pigs housed under TN conditions, but the dietary protein content had no effect.  相似文献   

Effects of Annealing and Concentration of Calcium Salts on Thermal and Rheological Properties of Maize Starch During an Ecological Nixtamalization Process     

David Santiago‐Ramos  Juan de Dios Figueroa‐Crdenas  Jos Juan Vles‐Medina  Rosalía Reynoso‐Camacho  Minerva Ramos‐Gmez  Marcela Gaytn‐Martínez  Eduardo Morales‐Snchez 《Cereal Chemistry》2015,92(5):475-480

The objective of the present work was to study the effect of annealing and concentration of Ca(OH)₂ (lime) and calcium salts on the thermal and rheological properties of maize starch during an ecological nixtamalization process. Thermal and rheological properties of maize starch changed during the ecological nixtamalization process because of three main causes: the annealing phenomenon, type of calcium salt, and calcium salt concentration. In all treatments thermal properties (T_o, T_p, and T_f) of nixtamal starch increased owing to the annealing process, whereas the type of salt or lime increased thermal properties and decreased pasting properties in this order: CaCl₂ > CaSO₄ > Ca(OH)₂ ≈ CaCO₃. This behavior was because of the dissociation of each salt or lime in water. Anions (OH⁻) can penetrate much more easily into the starch granule and start the gelatinization process by rupturing hydrogen bonds. Additionally, amylose‐lipid complexes were formed during the nixtamalization processes, as indicated by an increasing peak at 4.5 Å in X‐ray diffraction patterns.  相似文献   

Effects of 2 concentrations of sodium citrate on coagulation test results, von Willebrand factor concentration, and platelet function in dogs     

Morales F  Couto CG  Iazbik MC 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2007,21(3):472-475

BACKGROUND: Blood collection tubes containing 3.2% (0.109 M) sodium citrate, instead of 3.8% (0.129 M) sodium citrate, have recently become available in the United States. These tubes are visually indistinguishable from the traditional 3.8% sodium citrate tubes, except for wording on the label. Consequently, samples for hemostatic evaluation are frequently collected in tubes containing the lower concentration of sodium citrate. HYPOTHESIS: Results of hemostasis assays are different in samples collected in 3.2% versus 3.8% sodium citrate. ANIMALS: Twenty healthy dogs. METHODS: This study aimed at determining whether results of standard coagulation tests, von Willebrand factor concentration (vWF:Ag), and platelet function with the platelet function analyzer PFA-100a were affected by the different concentrations of sodium citrate. Blood samples were collected in tubes containing either 3.2% or 3.8% sodium citrate concentrations and processed routinely for coagulation assays (one-stage prothrombin time [OSPT], activated partial thromboplastin time [aPTT], fibrinogen concentration, and platelet count), vWF:Ag, and platelet function assays with a PFA-100. RESULTS: There was no significant difference between samples collected in 3.2% versus those collected in 3.8% sodium citrate for OSPT, aPTT, fibrinogen concentration, platelet count, or vWF:Ag. The closure times with collagen/adenosine diphosphate were significantly shorter (66 +/- 8.1 versus 74.8 +/- 9.7 seconds; P < .0001) with the 3.2% than with 3.8% sodium citrate concentration, and the hematocrit was significantly higher (47.9 +/- 5.6 versus 46.0 +/- 4.7 seconds; P = .03) in samples collected in 3.2% than in those collected in 3.8% sodium citrate. CONCLUSIONS AND CLINICAL IMPORTANCE: There is no clinically relevant effect of collection of blood into 3.2% or 3.8% sodium citrate.  相似文献   

Histological alterations in gills of shrimp Litopenaeus vannamei in low‐salinity waters under different stocking densities: Potential relationship with nitrogen compounds          下载免费PDF全文

Marcela G. Fregoso‐López  María S. Morales‐Covarrubias  Miguel A Franco‐Nava  Javier Ramírez‐Rochín  Juan F Fierro‐Sañudo  Jesús T Ponce‐Palafox  Federico Páez‐Osuna 《Aquaculture Research》2017,48(12):5854-5863

Two experimental modules with different stocking densities (M1 = 70 and M2 = 120 shrimp /m²) were examined weekly over a culture cycle in tanks with low‐salinity water (1.9 g/L) and zero water exchange. Results showed survival rates of 87.7 and 11.9% in M1 and M2, respectively. Water temperature, pH, dissolved oxygen, electrical conductivity and chlorophyll a were not significantly (p > .05) different between modules. In contrast, the concentrations of nitrogen compounds were significantly (p < .05) different between modules, except nitrite‐N (M2 were 2.31 ± 1.38 mg/L N‐TAN, 0.18 ± 0.49 mg/L N‐NO₂^? and 6.83 ± 6.52 mg/L N‐NO₃^?; in M1: 0.97 ± 0.73 mg/L N‐TAN, 0.05 ± 0.21 mg/L N‐NO₂^? and 0.63 ± 0.70 mg/L N‐NO₃^?). When waters of both modules reached higher levels of ammonia and nitrite, histological alterations were observed in gills. The histological alterations index (HAI) was higher in M2 (5‐112) than in M1 (2‐22).  相似文献   

Phenotypical parameters as a tool to evaluate the immunostimulatory effects of laminarin in Oncorhynchus mykiss          下载免费PDF全文

Byron Morales‐Lange  Jörn Bethke  Paulina Schmitt  Luis Mercado 《Aquaculture Research》2015,46(11):2707-2715

Laminarin is a β‐glucan from the brown algae Laminaria digitata (J.V. Lamour), which can activate innate immune responses. With the aim of developing a strategy to evaluate specific phenotypical parameters of the effects of laminarin in trout innate immunity, we (i) fed fish with laminarin‐supplemented diet (0.2 g kg^?1 day^?1) for 21 days and (ii) treated fish with a single dose of intraperitoneal injected laminarin (0.08 g kg^?1 fish). The evaluation of cellular and humoral immune parameters was established at phenotypic level by the phagocytic activity of headkidney macrophages and detection of inflammatory cytokines in head kidney and gill tissue by indirect ELISA. Results showed that both delivery methods of laminarin produce an increase in the phagocytic activity in head kidney macrophages and a significant increase in the production of TNFα and IL‐8 in gill tissue at day 21. Additionally, some of these parameters were significantly correlated (P < 0.025), which places them as new potential combined markers to detect activation of trout defense mechanisms by laminarin. These results highlight the importance of developing new protocols to quantitate immune parameters, in order to evaluate immunostimulants in fish farming.  相似文献   

Effects of tillage systems on soil characteristics, glomalin and mycorrhizal propagules in a Chilean Ultisol     

F. Borie  R. Rubio  J.L. Rouanet  A. Morales  G. Borie  C. Rojas 《Soil & Tillage Research》2006,88(1-2):253-261

Tillage affects the soil physical and chemical environment in which soil microorganisms live, thereby affecting their number, diversity and activity. However, soil disturbance generally has the greatest impact on biological properties, including both free and symbiotic fungal populations. Interest in more ecologically sustainable agricultural systems is rising with increasing recognition that agricultural intensification can adversely affect environmental quality. This paper discusses the effect of tillage system on some soil characteristics, such as pH, C, N and S levels, total and Olsen-P contents including some P forms associated with organic matter, glomalin contents and arbuscular mycorrhizae (AM) parameters, such as root colonization, spore number and total and active hyphal length. Measurements were in the sixth year of an on-going tillage-rotation experiment conducted on an Ultisol under no-till (NT), reduced tillage (RT) and conventional tillage with stubble mixed into the soil (CTS) or stubble burnt (CTB). Soil was sampled at two dates; after wheat (Triticum aestivum) harvest (autumn) and 6 months after subsequent grassland seeding (spring). Higher C, N, S, total P and fulvic acid-P concentrations and pH occurred under NT and RT than under CTS and CTB after wheat harvest. However, results at the second sampling were not consistent. AM spore number and active hyphal length were highest under NT having the greatest incidence on AM root colonization and P concentration in shoots of the pasture. Glomalin concentration was higher under NT and RT than under CTS and CTB but no differences in calculated glomalin to total C (ca. 5%) were found. It is concluded that a less disruptive effect of NT influences positively all soil characteristics and also increases P acquisition by the following crop in the rotation system.  相似文献