Comparison of Five Radioimmunoassay Systems for PAG Measurement: Ability to Detect Early Pregnancy in Cows

This study was conducted to describe the minimum detection limit, reproducibility, accuracy, specificity and parallelism of different pregnancy-associated glycoprotein radioimmunoassay (PAG-RIA) systems: RIA-497, RIA-706, RIA-780, RIA-809 and RIA-Pool. Their ability to distinguish between non-pregnant and pregnant females at day 30 after artificial insemination (AI) was investigated. The antisera were raised in rabbits against different PAG preparations. All RIA systems proved to be sensitive, repeatable and accurate for measuring PAG concentrations. The dilutions of plasma samples taken at an early stage of pregnancy were found to be parallel to the standard curves. No cross-reaction was observed with different carbohydrates, either with Pregnant Mare Serum Gonadotropin (PMSG) or human Chorionic Gonadotropin (hCG). The concentrations of PAG in pregnant females at day 30 after AI were shown to be higher with the use of antisera R#706, R#780, R#809 and Pool when compared with antiserum R#497. All the RIA systems gave 100% sensitivity and negative predictive values. On the other hand, the use of antisera R#780 and R#809 resulted in lower specificity and positive predictive values. The present study clearly shows that the ability of PAG-RIA systems to diagnose pregnancy specifically at day 30 after AI can be improved by using a combination of antisera raised against different forms of PAG.     

Olivine and pyroxene diversity in the crust of Mars

Data from the Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) on the Mars Express spacecraft identify the distinct mafic, rock-forming minerals olivine, low-calcium pyroxene (LCP), and high-calcium pyroxene (HCP) on the surface of Mars. Olivine- and HCP-rich regions are found in deposits that span the age range of geologic units. However, LCP-rich regions are found only in the ancient Noachian-aged units, which suggests that melts for these deposits were derived from a mantle depleted in aluminum and calcium. Extended dark regions in the northern plains exhibit no evidence of strong mafic absorptions or absorptions due to hydrated materials.     

Validation of a Field Based Chromatin Dispersion Assay to Assess Sperm DNA Fragmentation in the Bottlenose Dolphin (Tursiops truncatus)

Over the last two decades, there have been significant advances in the use of assisted reproductive technology for genetic and reproductive management of captive dolphin populations, including evaluation of sperm DNA quality. This study validated a customized sperm chromatin dispersion test (SCDt) for the bottlenose dolphin (Tursiops truncatus) as a means of assessing sperm DNA damage both in the field and in the laboratory. After performing the SCDt, two different sperm morphotypes were identified: (i) sperm with fragmented DNA showed large haloes of dispersed DNA fragments emerging from a compact sperm nucleoid core and (ii) sperm containing non‐fragmented DNA displayed small compact haloes surrounded by a dense core of non‐dispersed DNA and protein complex. Estimates of sperm DNA fragmentation by means of SCDt were directly comparable to results obtained following a two‐tailed comet assay and showed a significant degree of correlation (r = 0.961; p < 0.001). This investigation also revealed that the SCDt, with minor modifications to the standard protocol, can be successfully conducted in the field using a LED florescence microscopy obtaining a high correlation (r = 0.993; p = 0.01) between the data obtained in the laboratory and in the field.     

Gamma Interferon Production and Plasma Concentrations of Pregnancy‐Associated Glycoproteins 1 and 2 in Gestating Dairy Cows Naturally Infected With Neospora caninum

Gamma interferon (IFN‐γ) production and cross‐breed pregnancy have been attributed a role in protecting dairy cows infected with Neospora caninum against abortion. Plasma levels of pregnancy‐associated glycoproteins‐1 (PAG‐1) are a marker of placental/foetal well‐being and of PAG‐2 is an abortion risk indicator in chronically N. caninum‐infected animals. The present study examines, in cross‐breed pregnancies, interactions between IFN‐γ production and levels of PAG‐1 and PAG‐2 in non‐aborting naturally Neospora‐infected dairy cows. Data were obtained from 60 pregnant Holstein‐Friesian cows: 44 Neospora‐seropositive and 16 Neospora‐seronegative; 12 became pregnant using Holstein‐Friesian semen and 48 using Limousin semen. Blood samples were collected on Days 40, 90, 120, 150, 180 and 210 of gestation. Gamma interferon was only detected in the plasma of nine of the 44 Neospora‐seropositive cows, all of them became pregnant using Limousin semen. Through GLM procedures, in cows inseminated with Limousin semen and Neospora‐seropositive cows showing no IFN‐γ production, PAG‐1 concentrations were high and increased throughout gestation compared to the levels detected in cows inseminated with Holstein‐Friesian semen and Neospora‐seropositive cows producing IFN‐γ, respectively. In Neospora‐seronegative cows and in Neospora‐seropositive cows showing no IFN‐γ production, significantly increased PAG‐2 concentrations were observed on gestation Day 120. Our findings indicate that IFN‐γ production correlates negatively and the production of antibodies against N. caninum is uncorrelated with plasma PAG concentrations during gestation in Neospora‐infected dairy cows. Accordingly, IFN‐γ production could be linked to the transplacental migration of tachyzoites, which may cause a reduction in PAG levels.     

Summer evolution of the north polar cap of Mars as observed by OMEGA/Mars Express

The Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) visible-infrared imaging spectrometer extensively observed regions of Mars with latitudes above 70 degrees N in late 2004 (heliocentric longitude from Ls 93 degrees to Ls 127 degrees ). The extent of water ice at the surface and the size of ice grains were monitored as a function of time. Bright, small-grained frost, which initially covered a large fraction of the polar cap, waned in favor of large-grained ice. In outlying regions, dominated by large-grained ice, the albedo increased over the period. Evaluating the dust content was model dependent. However, contamination of ice by dust was low.     

Mars surface diversity as revealed by the OMEGA/Mars Express observations

The Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) investigation, on board the European Space Agency Mars Express mission, is mapping the surface composition of Mars at a 0.3- to 5-kilometer resolution by means of visible-near-infrared hyperspectral reflectance imagery. The data acquired during the first 9 months of the mission already reveal a diverse and complex surface mineralogy, offering key insights into the evolution of Mars. OMEGA has identified and mapped mafic iron-bearing silicates of both the northern and southern crust, localized concentrations of hydrated phyllosilicates and sulfates but no carbonates, and ices and frosts with a water-ice composition of the north polar perennial cap, as for the south cap, covered by a thin carbon dioxide-ice veneer.     

Sulfates in the north polar region of Mars detected by OMEGA/Mars Express

The Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) imaging spectrometer observed the northern circumpolar regions of Mars at a resolution of a few kilometers. An extended region at 240 degrees E, 85 degrees N, with an area of 60 kilometers by 200 kilometers, exhibits absorptions at wavelengths of 1.45, 1.75, 1.94, 2.22, 2.26, and 2.48 micrometers. These signatures can be unambiguously attributed to calcium-rich sulfates, most likely gypsum. This region corresponds to the dark longitudinal dunes of Olympia Planitia. These observations reveal that water alteration played a major role in the formation of the constituting minerals of northern circumpolar terrains.     

Pregnancy-associated Glycoprotein Profile during the First Trimester of Pregnancy in Egyptian Buffalo Cows

Pregnancy-associated glycoprotein (PAG) concentrations were measured in buffalo cows starting from day 28 after breeding. Oestrus was synchronized in 10 buffaloes using two injections of 25 mg prostraglandin (PG)F_{2 α} (Lutalyse^®) at a 11-day interval. Blood sampling was conducted nearly twice weekly. Results indicated that plasma PAG concentrations in non-pregnant buffaloes were low (<0.20 ng/ml) during the whole experimental period (day 28 to 103), while in pregnant animals plasma PAG levels increased from day 28 (4.48 ± 0.92 ng/ml) until day 41 (27.27 ± 6.74 ng/ml), remaining high (20.71 ± 9.20 ng/ml) until day 103. Progesterone levels were significantly (p < 0.0001) higher in pregnant (3.51–4.80 ng/ml) than in non-pregnant buffaloes (0.28–1.52 ng/ml). A significant difference (p < 0.0001) in plasma PAG concentrations between pregnant and non-pregnant animals starting at day 28 after breeding suggests that PAG-radioimmunoassay could be suitable for pregnancy diagnosis in buffaloes during this period. In conclusion, PAG test offers the advantages that it requires a single plasma sample for early pregnancy diagnosis as well as the accuracy of the test for the detection of pregnancy as early as day 28.     

Pan‐continental invasion of Pseudorasbora parva: towards a better understanding of freshwater fish invasions

In recent years, policy‐makers have sought the development of appropriate tools to prevent and manage introductions of invasive species. However, these tools are not well suited for introductions of non‐target species that are unknowingly released alongside intentionally‐introduced species. The most compelling example of such invasion is arguably the topmouth gudgeon Pseudorasbora parva, a small cyprinid species originating from East Asia. A combination of sociological, economical and biological factors has fuelled their rapid invasion since the 1960s; 32 countries (from Central Asia to North Africa) have been invaded in less than 50 years. Based on a combination of monitoring surveys (2535 populations sampled) and literature reviews, this paper aims to quantify and characterise important invasion parameters, such as pathways of introduction, time between introduction and detection, lag phase and plasticity of life history traits. Every decade, five new countries have reported P. parva introduction, mainly resulting from the movement of Chinese carps for fish farming. The mean detection period after first introduction was 4 years, a duration insufficient to prevent their pan‐continental invasion. High phenotypic plasticity in fitness related traits such as growth, early maturity, fecundity, reproductive behaviour and the ability to cope with novel pathogens has predisposed P. parva to being a strong invader. The Pseudorasbora parva invasion has provided quantitative data for the development of 1) early warning systems across different spatial scales; 2) rapid eradication programmes prior to natural spread in open systems and 3) sound risk assessments with emphasis on plasticity of life history traits.