The cornea of Guinea pig: structural and functional studies     

Thamara A. Cafaro  Susana G. Ortiz  Cristina Maldonado†  Fernando A. Espósito‡  Juan O. Croxatto§  Alejandro Berra¶  Omar L. Ale‡  Juan I. Torrealday‡  Enrique A. Urrets-Zavalía‡  Julio A. Urrets-Zavalía‡  Horacio M. Serra 《Veterinary ophthalmology》2009,12(4):234-241

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Effects of alpha2-adrenergic receptor agonists on urine production in horses deprived of food and water     

Nuñez E  Steffey EP  Ocampo L  Rodriguez A  Garcia AA 《American journal of veterinary research》2004,65(10):1342-1346

OBJECTIVE: To quantitate the dose- and time-related effects of IV administration of xylazine and detomidine on urine characteristics in horses deprived of feed and water. ANIMALS: 6 horses. PROCEDURE: Feed and water were withheld for 24 hours followed by i.v. administration of saline (0.9% NaCI) solution, xylazine (0.5 or 1.0 mg/kg), or detomidine (0.03 mg/kg). Horses were treated 4 times, each time with a different protocol. Following treatment, urine and blood samples were obtained at 15, 30, 60, 120, and 180 minutes. Blood samples were analyzed for PCV and serum concentrations of total plasma solids, sodium, and potassium. Urine samples were analyzed for pH and concentrations of glucose, proteins, sodium, and potassium. RESULTS: Baseline (before treatment) urine flow was 0.30 +/- 0.03 mL/kg/h and did not significantly change after treatment with saline solution and low-dose xylazine but transiently increased by 1 hour after treatment with high-dose xylazine or detomidine. Total urine output at 2 hours following treatment was 312 +/- 101 mL versus 4,845 +/- 272 mL for saline solution and detomidine, respectively. Absolute values of urine concentrations of sodium and potassium also variably increased following xylazine and detomidine administration. CONCLUSIONS AND CLINICAL RELEVANCE: Xylazine and detomidine administration in horses deprived of feed and water causes transient increases in urine volume and loss of sodium and potassium. Increase in urine flow is directly related to dose and type of alpha2-adrenergic receptor agonist. Dehydration in horses may be exacerbated by concurrent administration of alpha2-adrenergic receptor agonists.  相似文献   

Monitoring glyphosate residues in transgenic glyphosate-resistant soybean     

Arregui MC  Lenardón A  Sanchez D  Maitre MI  Scotta R  Enrique S 《Pest management science》2004,60(2):163-166

The availability of Roundup Ready (RR) varieties of soybean has increased the use of glyphosate for weed control in Argentina. Glyphosate [(N-phosphonomethyl)glycine] is employed for the eradication of previous crop vegetation and for weed control during the soybean growing cycle. Its action is effective, and low environmental impact has been reported so far. No residues have been observed in soil or water, either of glyphosate or its metabolite, AMPA (aminomethylphosphonic acid). The objective of this work was to monitor glyphosate and AMPA residues in soybean plants and grains in field crops in Santa Fe Province, Argentina. Five sites were monitored in 1997, 1998 and 1999. Individual soybean plants were sampled from emergence to harvest, dried and ground. Analysis consisted in residue extraction with organic solvents and buffers, agitation, centrifugation, clean-up and HPLC with UV detection. In soybean leaves and stems, glyphosate residues ranged from 1.9 to 4.4 mg kg(-1) and from 0.1 to 1.8 mg kg(-1) in grains. Higher concentrations were detected when glyphosate was sprayed several times during the crop cycle, and when treatments approached the flowering stage. AMPA residues were also detected in leaves and in grains, indicating metabolism of the herbicide.  相似文献   

Management factors associated with Babesia bovis seroprevalence in cattle from eastern Yucatán, Mexico.     

Jos  L. Solorio-Rivera  Roger I. Rodrí  guez-Vivas  Enrique P  rez-Gutierrez  Gale Wagner 《Preventive veterinary medicine》1999,40(3-4):261-269

The effect of management on the seroprevalence of Babesia bovis was studied in 399 Bos indicus cattle 1–2 years old from 92 farms in the eastern Yucatán, México. The management factors studied were: farm-type, production system, herd size, farm size, stocking density, vector control, dipping interval, type of dipping, type of acaricide and cattle introduction to the farm. A cross-sectional study was carried out (2-stage cluster sampling). The number of serum samples was proportionally distributed according to the number of farms in the nine locations of eastern Yucatán, México (399 animals from 92 farms). Antibody activity to B. bovis was tested using an indirect ELISA. The farms with a seroprevalence ≤75% were considered as cases and those with seroprevalence >75% were considered as controls. The variables with p ≤ 0.20 were included in fixed effects logistic regression. The seroprevalence of the zone was 73.8% (66.3–81.3%). The following risk factors were found: Stocking density (<1 head/ha, OR = 4.04, CI (OR) = 1.20–13.62) and dipping interval (>60 days, OR = 5.07 CI (OR) = 1.26–20.48).  相似文献   

Management factors associated with Babesia bovis seroprevalence in cattle from eastern Yucatán, Mexico     

Jos L. Solorio-Rivera  Roger I. Rodríguez-Vivas  Enrique Prez-Gutierrez  Gale Wagner 《Preventive veterinary medicine》1999,40(3-4)

The effect of management on the seroprevalence of Babesia bovis was studied in 399 Bos indicus cattle 1–2 years old from 92 farms in the eastern Yucatán, México. The management factors studied were: farm-type, production system, herd size, farm size, stocking density, vector control, dipping interval, type of dipping, type of acaricide and cattle introduction to the farm. A cross-sectional study was carried out (2-stage cluster sampling). The number of serum samples was proportionally distributed according to the number of farms in the nine locations of eastern Yucatán, México (399 animals from 92 farms). Antibody activity to B. bovis was tested using an indirect ELISA. The farms with a seroprevalence ≤75% were considered as cases and those with seroprevalence >75% were considered as controls. The variables with p ≤ 0.20 were included in fixed effects logistic regression. The seroprevalence of the zone was 73.8% (66.3–81.3%). The following risk factors were found: Stocking density (<1 head/ha, OR = 4.04, CI (OR) = 1.20–13.62) and dipping interval (>60 days, OR = 5.07 CI (OR) = 1.26–20.48).  相似文献   

Fishery indicators during a predictable aggregation of Atlantic sharpnose sharks Rhizoprionodon terraenovae in the southern Gulf of Mexico: An alternative to assess a heterogeneous data‐poor fishery     

Esteban Bada‐Snchez  Juan Carlos Prez‐Jimnez  Luis Enrique Martínez‐Cruz  Ivn Mndez‐Loeza  Eloy Sosa‐Cordero 《Fisheries Management and Ecology》2019,26(4):354-364

Small‐scale fisheries in the southern Gulf of Mexico that catch Rhizoprionodon terraenovae (Richardson) are heterogeneous and data‐poor. Fishery‐dependent monitoring was conducted from 2010 to 2017, including a target season during an aggregation of this species to estimate data‐poor fishery indicators. During the target season, the average sizes for females and males (95.3 and 89.8 cm total length, respectively) were recorded, a global male sex bias (1:1.7), the highest percentage of mature sharks for all years (>89%), the highest values of CPUE (20.1 sharks/day) and size‐selectivity higher than the size at maturity. The spawning potential ratio was over 0.6 (reference point of 0.71) in the combined (target and non‐target) and target seasons for all years, which suggests that the fishery stock is not healthy. Annual assessment of this fishery can be carried out through monitoring during the target season, where management is more feasible to implement.  相似文献   

Fuzzy-logic-based feeder system for intensive tilapia production (<Emphasis Type="Italic">Oreochromis niloticus</Emphasis>)     

Genaro M. Soto-Zarazúa  Enrique Rico-García  Rosalía Ocampo  R. G. Guevara-González  Gilberto Herrera-Ruiz 《Aquaculture International》2010,18(3):379-391

In high-fish-density aquaculture systems, tilapia producers are compelled to provide 100% of food required to obtain profitable growth rates. It is well known that fish have a low food conversion rate and feeding represents the most important expenditure, approximately 40% of total production cost. Therefore, precise quantities of food should be provided to avoid water pollution and economic losses due to food waste when water conditions are inadequate for fish feeding. A way to control food provisions in this work was determined by the conditions of temperature, dissolved oxygen, fish age, and body weight, since these variables have a direct effect on fish metabolism and growth. Thus, a change in metabolism is reflected in a modification of energy requirements and, as a consequence, in variations of food consumption. In this work, a new feeder with fuzzy-logic control algorithms is proposed for fish feeding; this technique allows farmer knowledge to be taken into account in a series of if–then-type rules. To define these rules the temperature and dissolve oxygen were considered in order to provide precise food quantities. The results show minimal differences in growth (P > 0.05) between treatments, important food saving of 29.12% (equivalent to 105.3 kg), and lower water pollution (reduced water dissolved solids and ammonium components) compared with timed feeders. This system provides an important contribution to sustainability of intensive aquaculture systems, increasing productivity and profitability, and optimizing water use.  相似文献   

Stock enhancement programme for black sea bream, Acanthopagrus schlegelii (Bleeker), in Hiroshima Bay, Japan: a review   总被引：1，自引：0，他引：1  

Enrique Blanco Gonzalez  Tetsuya Umino  & Kazuya Nagasawa 《Aquaculture Research》2008,39(12):1307-1315

This paper reviews the stock enhancement programme for black sea bream ( Acanthopagrus schlegelii ) in Hiroshima Bay. This bay is one of the biggest production areas for black sea bream in Japan, accounting for about 10% of the total catch of the species in this country in 2004. After intensive fishing pressure caused a drastic decline in the catch of the species in this bay in the 1970s, a stock enhancement programme was conducted in its northern part since 1982 to restore the depleted population. The number of black sea bream juveniles released in 1996 surpassed 9 million, representing the third main species stocked in Japan. Almost 1.4 million of these juveniles were released into Hiroshima Bay. The fast acclimatization of hatchery-reared juveniles released into the bay may have contributed to the recovery of landings in the late 1980s and 1990s. However, this recovery was accompanied by a reduction in the market price of black sea bream. Further studies to assess the effectiveness of the stock enhancement programme as well as the carrying capacity of Hiroshima Bay to maintain the stock of black sea bream at a stable, healthy level are desirable. The necessity of evaluating the secondary effects derived from using a reduced number of breeders as well as finding new markets are suggested.  相似文献   

Postmortem Biochemical and Microbiological Changes in Loricariid Catfish (Pterygoplichthys disjunctivus) Muscle During Ice Storage     

Enrique Marquez-Rios  Ramon Pacheco-Aguilar  Victor M. Ocano-Higuera  Celia O. García-Sifuentes  Susana M. Scheuren-Acevedo 《Journal Of Aquatic Food Product Technology》2013,22(1):105-113

ABSTRACT

Postmortem biochemical and microbiological changes in loricariid catfish (Pterygoplichthys disjunctivus) muscle were evaluated during ice storage for 20 days. Values of pH remained stable for 15 days (7.4 ± 0.2), and total volatile base-nitrogen (TVB-N) remained under acceptable limits throughout storage, with a final value of 25.2 ± 3.3 mg N/100 g muscle at Day 20. Adenosine-5´-triphosphate (ATP) and derivatives followed a postmortem degradation pattern similar to other species, with the K-value being the best freshness loss indicator. Biochemical and microbiological changes indicated that the shelf life of iced loricariid catfish muscle was 15 days under optimal (0°C) storage conditions.  相似文献   

Ovine toxoplasmosis: Seroconversion during pregnancy and lamb birth rate in Uruguayan sheep flocks     

Enrique Savio  Alberto Nieto 《Veterinary parasitology》1995,60(3-4):241-247

Specific anti-Toxoplasma gondii antibodies were analyzed by latex agglutination during the 5 months of pregnancy in the serum of sheep from two flocks in the Uruguayan north-west: one flock (79 sheep) kept under an intensive management system and the other (494 sheep) kept under an extensive management system. Titers obtained using the latex test correlated with those obtained by indirect immunofluorescence. Pregnancy was confirmed by laparoscopy in all sheep from the smaller flock and by determination of serum progesterone levels in the seroconverted sheep from the larger flock. The percentage of sheep originally exhibiting significant serum levels of anti-T. gondii anti-bodies (13.9% in the smaller flock and 28.5% in the larger one) as well as the observed levels of seroconversion (22.8% and 7.7%, respectively), indicated a high prevalence of this infection in the north-west of Uruguay. In addition, birth rates of seroconverted sheep in the larger flock were significantly different from those of non-seroconverted animals. These results, although preliminary, suggest that Toxoplasma infection would produce considerable economic losses in extensive ovine production in Uruguay.  相似文献