Relation between the major histocompatibility (B) locus and autoimmune thyroiditis in obese chickens

Obese strain chickens develop circulating autoantibodies to thyroglobulin and lymphocytic infiltration of their thyroids during aging. Two alleles, B(1) and B(4), are found with high gene frequency at the major histocompatibility (B) locus. Greater pathology and higher antibody titers are observed in B(1)B(1) and B(1)B(4) birds than in their B(4)B(4) siblings.     

Holocene eruptive activity of el chichon volcano, chiapas, Mexico

Geologic and radiometric-age data indicate that El Chichón was frequently and violently active during the Holocene, including eruptive episodes about 600, 1250, and 1700 years ago and several undated, older eruptions. These episodes, involving explosive eruptions of sulfur-rich magma and associated dome-growth processes, were apparently separated by intervals of approximately 350 to 650 years. Some of El Chichón's eruptions may correlate with unusual atmospheric phenomena around A.D. 1300 and possibly A.D. 623.     

A model for conjunctive use of groundwater and surface waters for control of irrigation salinity

Changes in the hydrologic balance in many irrigation areas, including those in the Murray Basin, Australia, have resulted in high watertables and salinity problems. However, where suitable aquifers exist, groundwater pumping and subsequent irrigation application after mixing with surface waters (referred to as conjunctive water use) can control salinity and watertable depth and improve productivity of degraded land. In order to assess where conjunctive water use will successfully control salinity, it is necessary to estimate the effects of pumped groundwater salinity on rootzone salinity. A simple steady rate model is derived for this purpose from mass conservation of salt and water. The model enables an estimate to be made of rootzone salinity for any particular salinity level of the groundwater being used in conjunction with surface water; this enables calculation of the required crop salt tolerance to prevent yield reductions. The most important input parameters for the model are groundwater salinity, the annual depth of class A pan evaporation, the annual depth of rainfall, the salinity of irrigation water, and a leaching parameter. For model parameters nominated in this paper, where groundwater salinity reaches 5 dS/m a crop threshold salt tolerance greater than 1.6 dS/m is required to avoid yield reductions. Where groundwater salinity approaches 10 dS/m, a crop threshold tolerance of 3 dS/m is required. Whilst the model derived indicates that rootzone salinity is sensitive to groundwater salinity, rootzone salinity is insensitive to leaching for leaching fractions commonly encountered (0.1 to 0.4). The insensitivity to leaching means that it could be expected that similar yields could be attained on heavy or light textured soils. This insensitivity also implies that there is no yield penalty from increasing the mass of pumped salt by pumping to achieve maximum watertable control in addition to leaching. The model developed is also used to estimate yield reductions expected under conjunctive use, for any particular levels of groundwater salinity and crop salt tolerance.     

Bone morphogenetic protein 15 supplementation enhances cumulus expansion,nuclear maturation and progesterone production of in vitro-matured bovine cumulus-oocyte complexes

In vitro embryo production (IVP) efficiency is reduced when compared to in vivo. The basic knowledge of bovine in vitro oocyte maturation (IVM) mechanisms provides support to improve in vitro embryo production yields. The present study assessed the effects of bone morphogenetic protein 15 (BMP15), fibroblast growth factor 16 (FGF16) and their combined action on cumulus cells (CC) expansion, oocyte and CC DNA fragmentation, oocyte nuclear maturation, energetic metabolism and progesterone production in bovine IVM. Cumulus-oocyte complexes (COC) were matured in control or supplemented media containing BMP15 (100 ng/ml), FGF16 (10 ng/ml) or BMP15 combined with FGF16; and assessed at 0 and 22 hr of IVM. BMP15 alone or its association with FGF16 enhanced cumulus expansion. BMP15 decreased DNA fragmentation in both CC and oocytes, and improved oocyte nuclear maturation rate. In addition, BMP15 increased CC progesterone production, an effect not previously reported. The present study reinforces previous data pointing to a beneficial influence of BMP15 during IVM, while providing novel evidence that the underlying mechanisms involve increased progesterone production.     

Evaluation of tumescent local anesthesia in cats undergoing unilateral mastectomy

ObjectiveTo evaluate the analgesic efficacy and safety of tumescent local anesthesia (TLA) in cats undergoing unilateral mastectomy.Study designProspective clinical trial.AnimalsA total of 12 ovariohysterectomized female cats.MethodsAll animals were premedicated with pethidine (4 mg kg^–1) intramuscularly (IM), followed by induction of anesthesia with propofol (5 mg kg^–1) intravenously and maintenance with isoflurane in oxygen. A refrigerated TLA solution (15 mL kg^–1, 8 °C) was injected using a Klein cannula. The solution was composed of 0.5 mL of epinephrine (1 mg mL^–1) and 40 mL of 2% lidocaine added to 210 mL lactated Ringer’s solution (final lidocaine concentration 0.32%). Heart and respiratory rates, systolic arterial blood pressure, temperature and oxygen saturation were measured during anesthesia. Blood samples were collected from the jugular vein for measurement of plasma lidocaine concentration using high performance liquid chromatography. Postoperative pain scores were evaluated hourly for 6 hours. Analgesic rescue was performed with tramadol (2 mg kg^–1) IM and meloxicam (0.15 mg kg^–1) subcutaneously.ResultsPlasma lidocaine concentration peaked at 90 minutes after injection of TLA, but no concentration considered toxic for the species was measured. The median postoperative analgesia time was 6 hours after injection of TLA.ConclusionsThis study found that TLA prevented sympathetic response to noxious stimuli during anesthesia and provided satisfactory postoperative analgesia in cats submitted to total unilateral mastectomy, with no apparent signs of toxicity.Clinical relevanceTLA can prevent sympathetic stimulation resulting from noxious stimuli during anesthesia, promoting good intraoperative conditions, proving to be a viable addition to analgesia in cats submitted to a total unilateral mastectomy.     

Compensatory density dependence in fish populations: importance, controversy, understanding and prognosis

Density‐dependent processes such as growth, survival, reproduction and movement are compensatory if their rates change in response to variation in population density (or numbers) such that they result in a slowed population growth rate at high densities and promote a numerical increase of the population at low densities. Compensatory density dependence is important to fisheries management because it operates to offset the losses of individuals. While the concept of compensation is straightforward, it remains one of the most controversial issues in population dynamics. The difficulties arise when going from general concepts to specific populations. Compensation is usually quantified using some combination of spawner–recruit analysis, long‐term field monitoring or manipulative studies, and computer modelling. Problems arise because there are limitations to each of these approaches, and these limitations generally originate from the high uncertainty associated with field measurements. We offer a hierarchical approach to predicting and understanding compensation that ranges from the very general, using basic life‐history theory, to the highly site‐specific, using detailed population models. We analyse a spawner–recruit database to test the predictions about compensation and compensatory reserve that derive from a three‐endpoint life‐history framework designed for fish. We then summarise field examples of density dependence in specific processes. Selected long‐term field monitoring studies, manipulative studies and computer modelling examples are then highlighted that illustrate how density‐dependent processes led to compensatory responses at the population level. Some theoretical and empirical advances that offer hope for progress in the future on the compensation issue are discussed. We advocate an approach to compensation that involves process‐level understanding of the underlying mechanisms, life‐history theory, careful analysis of field data, and matrix and individual‐based modelling. There will always be debate if the quantification of compensation does not include some degree of understanding of the underlying mechanisms.     

The Impact of Demographic,Social, and Environmental Factors on the Development of Steroid‐Responsive Meningitis‐Arteritis (SRMA) in the United Kingdom

Background

Steroid‐responsive meningitis‐arteritis (SRMA) is an inflammatory disease of dogs that is suspected to be immune‐mediated. The development of other immune‐mediated diseases has been linked to vaccinations, time of the year, geographic location, sex, neuter status, and breed.

Hypothesis/Objectives

To identify if the development of SRMA is associated with time of year, vaccination, geographic location, sex, neuter status, and breed.

Animals

Sixty SRMA cases and 180 controls, all ≤24 months of age and matched for year of presentation, from a referral hospital population in the United Kingdom.

Methods

Retrospective case‐control study with unconditional logistic regression analysis.

Results

Beagles (P = .001), Border Collies (P = .001), Boxers (P = .032), Jack Russell Terriers (P = .001), Weimaraners (P = .048), and Whippets (P < .001) had significantly greater odds of developing SRMA in this population of dogs. Vaccination, time of year, geographic category, sex, and neuter status did not increase the odds of developing SRMA.

Conclusions and Clinical Importance

Only breed increased the odds of developing SRMA. It would be prudent to investigate the genetics of the identified breeds to help elucidate the etiopathogenesis of SRMA.     

Rearing conditions influence nutrient availability of plant extracts supplemented diets when fed to broiler chickens

The effects of a standardised mixture of essential oils, including 5% carvacrol, 3% cinnamaldehyde and 2% capsicum (XT 6930; Pancosma S.A), on dietary apparent metabolisable energy corrected for nitrogen retention (AMEn), nutrient digestibility and mucin secretions, measured as sialic acid (SA) were investigated in broilers fed on the same diet but reared under different conditions, that is, cages and floor pens littered with wood shavings used in previous broiler study. The use of XT reduced (p < 0.05) nitrogen digestibility (0.585 vs. 0.544) and tended (p = 0.072) to reduce dry matter digestibility (0.733 vs. 0.717) of the diet when fed to birds reared in cages. However, XT supplementation improved (p < 0.05) fat digestibility (0.844 vs. 0.862) and tended (p = 0.093) to increase AMEn (14.01 vs. 14.25 MJ/kg DM) of the same diet when fed to broilers reared in floor pens. Essential oils supplementation tended (p = 0.059) to increase the secretion of SA, when fed to birds reared in cages (11.24 vs. 14.18 μg), but did not influence (p > 0.05) the SA secretion from birds reared in floor pens. The results obtained from the cage study tend to be the opposite of those obtained from the floor pen study. This suggests that the efficiency of dietary plant extracts may be influenced by the rearing/hygienic conditions of poultry. Based on the overall results, it can be concluded that information on rearing conditions should be taken into account for more complete interpretation of the experimental data emanating from experiments involving use of essential oils typified by those considered in this study.