Uterine Infection Influences Size and Follicular Fluid Composition of the Largest Follicle in Buffalo (Bubalus bubalis)

The effect of uterine infection on size and follicular fluid composition of the largest follicle was studied in buffalo. Reproductive tracts were collected from 102 graded Murrah buffaloes at an abattoir. Uterine infection was diagnosed by physical examination of uterine mucus, white side test and uterine cytology. Samples with pus‐containing mucus, positive reaction on white side test and/or >5% neutrophils were considered to be positive for uterine infection. Diameter of the largest follicle was measured, and follicular fluid was aspirated and assayed for nitric oxide (NO), ascorbic acid (AA), cholesterol, oestradiol (E₂) and progesterone (P₄). Infected buffaloes had smaller‐sized (p < 0.0001) largest follicles than non‐infected buffaloes. Follicular fluid collected from the largest follicle in infected buffaloes had greater (p < 0.0001) NO and P₄ concentrations coincident with lesser AA (p < 0.001), cholesterol (p < 0.0001) and E₂ (p < 0.0001) concentrations. Results indicated that uterine infection has an inhibitory effect on growth of the largest follicle in buffalo. The changes in follicular fluid composition in infected buffaloes suggest that the direct effect of uterine infection on ovarian function may be mediated through an alteration in the follicular microenvironment. Greater NO and lesser AA concentrations in the follicular fluid of infected animals are novel findings.     

Attitudes of dog owners to neutering pets: demographic data and effects of owner attitudes

SUMMARY A survey of the attitudes of dog owners to desexing male and female dogs was conducted in the Brisbane area. Over 15800 replies (35% response) were returned for analyses and included both demographic and attitude data. The most common reasons given by owners for not having the dog desexed were that it was unnecessary or they wanted to breed from it or could not afford it or did not agree with it or that the dog was too old or it might get fat. Nearly twice as many male owners agreed that desexing male dogs removed maleness and also more males agreed with the question “Do you equate dog sexuality with human sexuality?” Female owners were more aware than males that their female dogs did not need to have a season (oestrus) or a litter before being desexed. More male owners thought that desexing changed a male or female dog's personality. A disturbing fact was that 61.1% of male owners and 47.3% of female owners would now not have their dog desexed if it had not already been done. More male than female dog owners were ignorant about whether desexing changed personality, made dogs frustrated, or if female dogs should have a season or a litter before desexing. The study showed a gender bias in owner attitudes to all the attitude questions.     

Mountain pine beetle scarring of lodgepole pine in south-central Oregon

Three forest disturbance periods, 1973—present, 1922–1929, and 1827–1946 were determined by aging scars on stems of lodgepole pine trees. All of the scars from the 1970's and 1920's, and most of the scars from the 1820's–40's were determined to be caused by the mountain pine beetle. A few scars from the earliest period may be the result of fire. Diagnostic characteristics of beetle scars are: resemblance to fire scars, pitch tubes, beetle emergence holes, blue stain, beetle galleries, retained bark on the scar face, and an orange or red discoloration around healthy sapwood. Beetle attacks tend to have a northeastern aspect and extend approximately two-thirds around tree boles at breast height.By recognizing beetle scars it is possible to accurately age previous mountain pine beetle attacks. Many scars which had been thought to be of fire origin are actually caused by the mountain pine beetle.     

Influences of Follicular Size on Parthenogenetic Activation and in Vitro Heat Shock on the Cytoskeleton in Cattle Oocytes

The availability of cow ovaries from the slaughterhouse has been very limited in Taiwan. To maximize the use of cow ovaries for research purposes, whole ovary dissection was performed and the developmental competence of the oocytes derived from different sizes of follicles was assessed by the rates of in vitro maturation (IVM) and parthenogenetic activation of the oocytes in Experiment 1 (Exp 1). Cumulus-oocyte complexes (COCs) derived from small (1-2 mm) and large (3-8 mm) follicles were subjected to standard IVM culture for 24 h. Mature oocytes were selected and then parthenogenetically activated using A23187 (5 microm, 5 min) or thimerosal (200 microm, 10 min) alone or combined with 6-dimethylaminopurine (2.5 mm and 3.5 h, respectively). Activation rates of the oocytes, neither from the large nor small follicles, were affected by different activation treatments (single or combined stimuli). Whereas maturation rates for the oocytes from large follicles were superior to those from small follicles in both the single (59% vs 45%) and combined treatments (76% vs 40%; p < 0.05). To understand how prolonged heat shock (HS) influences cytoskeletal configurations of mature bovine oocytes, in Experiment 2 (Exp 2), matured oocytes derived from large follicles were randomly allocated to different durations of HS treatments at 41.5 degrees C for 0 (C0h, control, n = 12), 1 (HS1h, n = 28), 2 (HS2h, n = 31), and 4 h (HS4h, n = 30). An additional control group was cultured for 4 h without HS (38.5 degrees C, 4 h, n = 35). Alterations in nuclear structures, microtubules (MTs), and microfilaments (MFs) of the oocytes were examined. Abnormalities in the chromosomes, spindle MTs and the percentages of oocytes with cytoplasmic MTs increased with time of HS treatment. The intensity of the MF distribution in the HS oocytes was also altered. Significant changes in the cytoskeleton after HS may be associated with the reduced development under hyperthermia and, perhaps, with the low pregnancy rates of the animals during hot seasons.     

Successful Low Dose Insemination of Flow Cytometrically Sorted Ram Spermatozoa in Sheep

The fertility of ram spermatozoa that had undergone flow cytometric sorting (MoFlo SX) and cryopreservation was assessed after low-dose insemination of synchronized Merino ewes. Oestrus was synchronized with progestagen-impregnated pessaries, PMSG and GnRH treatment. Ewes (n = 360) were inseminated with 1 x 10(6), 5 x 10(6) or 15 x 10(6) motile sorted frozen-thawed (S(1), S(5), or S(15) respectively) or non-sorted frozen-thawed (C(1), C(5) or C(15) respectively) spermatozoa from three rams. An additional group of ewes were inseminated with 50 x 10(6) motile non-sorted frozen-thawed spermatozoa (C(50)) to provide a commercial dose control. The percentage of ewes lambing after insemination was similar for C(50) (24/38, 63.2%), C(15) (37/54, 68.5%), S(15) (38/57, 66.7%), S(5) (37/56, 66.1%) and S(1) (32/52, 61.5%) groups (p > 0.05), but lower for C(5) (19/48, 39.6%) and C(1) (19/55, 34.5%) treatments (p < 0.05). This study demonstrates sorted ram spermatozoa are equally fertile to non-sorted spermatozoa even when inseminated at 2% of the dose. Furthermore, at very low artificial insemination doses (1 or 5 million motile) the fertility of sorted ram spermatozoa is superior to non-sorted spermatozoa inseminated in equal numbers. These results have significance for the future commercialization of sex-preselection technology in sheep as a reduction in the minimum effective sperm number will allow a corresponding decrease in the associated cost per dose.     

Perpetuating old ponderosa pine

We review current knowledge about the use of management treatments to reduce human-induced threats to old ponderosa pine (Pinus ponderosa) trees. We address the following questions: Are fire-induced damage and mortality greater in old than younger trees? Can management treatments ameliorate the detrimental effects of fire, competition-induced stress, and drought on old trees? Can management increase resistance of old trees to bark beetles? We offer the following recommendations for the use of thinning and burning treatments in old-growth ponderosa pine forests. Treatments should be focused on high-value stands where fire exclusion has increased fuels and competition and where detrimental effects of disturbance during harvesting can be minimized. Fuels should be reduced in the vicinity of old trees prior to prescribed burns to reduce fire intensity, as old trees are often more prone to dying after burning than younger trees. Raking the forest floor beneath old trees prior to burning may not only reduce damage from smoldering combustion under certain conditions but also increase fine-root mortality. Thinning of neighboring trees often increases water and carbon uptake of old trees within 1 year of treatment, and increases radial growth within several years to two decades after treatment. However, stimulation of growth of old trees by thinning can be negated by severe drought. Evidence from young trees suggests that management treatments that cause large increases in carbon allocation to radial xylem growth also increase carbon allocation to constitutive resin defenses against bark beetle attacks, but evidence for old trees is scarce. Prescribed, low-intensity burning may attract bark beetles and increase mortality of old trees from beetle attacks despite a stimulation of bole resin production.     

Percolation of core melts at lower mantle conditions

Experiments at high pressure and temperature to determine the dihedral angle of core melts in lower mantle phases yielded a value of approximately 71 degrees for perovskite-dominated matrices. This angle, although greater than the 60 degrees required for completely efficient percolation, is considerably less than the angles observed in mineral matrices at upper mantle pressure-temperature conditions in experiments. In other words, molten iron alloy can flow much more easily in lower mantle mineralogies than in upper mantle mineralogies. Accordingly, although segregation of core material by melt percolation is probably not feasible in the upper mantle, core formation by percolation may be possible in the lower mantle.     

Challenges and a checklist for biodiversity conservation in fire-prone forests: Perspectives from the Pacific Northwest of USA and Southeastern Australia

Conserving biodiversity in fire-prone forest ecosystems is challenging for several reasons including differing and incomplete conceptual models of fire-related ecological processes, major gaps in ecological and management knowledge, high variability in fire behavior and ecological responses to fires, altered fire regimes as a result of land-use history and climate change, and the increasing encroachment into forest landscapes by humans. We briefly compare two ecologically distinct fire-prone forest regions, the Pacific Northwest, USA and southeastern Australia with the goal of finding ecological conservation generalities that transcend regional differences as well as differences in scientific concepts and management. We identify the major conceptual scientific and conservation challenges and then present a checklist of questions that need to be answered to implement place-based approaches to conserving biodiversity in fire-prone forest ecosystems. The two regions exhibit both similarities and differences in how biodiversity conservation is conceptualized and applied. Important research and management challenges include: understanding fire-prone systems as coupled natural-human systems, using the disturbance regime concept in multiple ways, dealing with large fire events, using language about the effects of fire with more precision, and researching and monitoring fire and biodiversity at multiple spatial scales. Despite the weaknesses of present conceptual models, it is possible to develop a checklist of principles or questions that can be used to guide management and conservation at local scales across systems. Our list includes: establishing the socio-economic context of fire management, identifying disturbance regimes that will meet conservation goals, moving beyond fuel treatments as a goal, basing management goals on vital attributes of species, and planning for large events including post-fire responses.