Experimental Neospora Caninum Infection in Pregnant Dairy Heifers Raises Concentrations of Pregnancy‐Associated Glycoproteins 1 and 2 in Foetal Fluids

Plasma concentrations of PAG‐1 are used for pregnancy diagnosis and as a marker of placental/foetal well‐being, while those of PAG‐2 may be an indicator of abortion risk in Neospora caninum‐infected cows. Studies have shown that N. caninum infection modifies PAG‐1 and PAG‐2 patterns in maternal blood plasma. However, no prior work has examined the effects of N. caninum infection on concentrations of PAGs in foetal fluids. In this study, PAG‐1, PAG‐2 and pH levels were determined in the amniotic and allantoic fluids of foetuses collected at 152 days of gestation from control uninfected dams and from dams experimentally infected with N. caninum on Day 110 of gestation. Foetal fluids from infected foetuses had significantly higher PAG‐2 concentrations (p = 0.026) and pH values (p = 0.02) than fluids from non‐infected foetuses. In infected foetuses, significantly higher concentrations of PAG‐1 (p < 0.001) and PAG‐2 (p < 0.001) were detected in fluid samples showing antibodies against N. caninum than those without antibodies. Moreover, pH values were significantly higher (p = 0.011) in foetal fluid samples with antibodies than in samples from non‐infected foetuses. In conclusion, this is the first report on the effect of N. caninum infection on PAG levels in foetal fluids. Our results indicate that following the experimental infection of dams with N. caninum on Day 110 of gestation, foetal fluids collected from the infected foetuses of these dams featured higher PAG‐1 and PAG‐2 levels and pH values than fluids from non‐infected controls, provided that the samples tested showed the presence of antibodies. The clinical implications of these findings are that following infection with N. caninum, most cows will experience some level of placental damage and that this injury correlates with foetal fluid PAG levels and pH.     

Application of 10% imidacloprid/50% permethrin to prevent Ehrlichia canis exposure in dogs under natural conditions

Canine monocytic ehrlichiosis (CME) caused by Ehrlichia canis is the most known canine tick-borne disease (TBD) spread throughout the world. Preventing tick bites is a priority to reduce the risk of TBDs and it was the aim of the present study to evaluate the efficacy of a combination of imidacloprid 10% and permethrin 50% (ImPer) (Advantix; Bayer AG, Germany) in a spot-on formulation to control CME under field conditions. On January-March 2005, 845 dogs from two kennels in southern Italy (kennels of Bari (KB)- and Ginosa (KG)), with a history of tick infestation were initially tested by serology and PCR assay for E. canis infection. Data on Leishmania infantum infection were also available from a previous study carried out on the same dog population. One hundred twenty-six dogs (14.9%) presented anti-E. canis antibodies with a relative prevalence of 15.6% (n=65 dogs in KB) and 14.2% (n=61 dogs in KG). Five hundred thirty-five animals found negative both for E. canis and L. infantum infections were enrolled in three groups (Group A--treated with ImPer once a month; Group B--treated every 2 weeks; and Group C--untreated control animals) and monitored for E. canis infection by serology and PCR in November 2005 (first follow-up) and in March 2006 (second follow-up). The E. canis infection was serologically revealed, at the first and/or second follow-up, in 26 animals from Group C in KB and KG (mean incidence density rate (IDR), 13.24%) while in none of the animals from Group A (KB and KG) and only in one animal from Group B (IDR 1.13%) in KG. The final protection efficacy of ImPer ranged from 95.57% to 100% in Groups B and A. At PCR only 15 dogs from KG were positive for Rickettsiales only at the first follow-up and at the sequence analysis two (both in Group C) revealed 100% homology with E. canis sequences while 13 with Anaplasma platys. Four out of 13 A. platys PCR-positive dogs were also seropositive for E. canis at one or both follow-ups. ImPer, by virtue of its repellent and acaricidal activity against ticks, has been shown to be efficacious to prevent E. canis infection in treated dogs living under natural conditions in endemic areas.     

Carbon Depletion by Plowing and its Restoration by No‐Till Cropping Systems in Oxisols of Subtropical and Tropical Agro‐Ecoregions in Brazil

The continuous use of plowing for grain production has been the principal cause of soil degradation. This project was formulated on the hypothesis that the intensification of cropping systems by increasing biomass‐C input and its biodiversity under no‐till (NT) drives soil restoration of degraded agro‐ecosystem. The present study conducted at subtropical [Ponta Grossa (PG) site] and tropical regions [Lucas do Rio Verde, MT (LRV) site] in Brazil aimed to (i) assess the impact of the continuous plow‐based conventional tillage (CT) on soil organic carbon (SOC) stock vis‐à‐vis native vegetation (NV) as baseline; (ii) compare SOC balance among CT, NT cropping systems, and NV; and (iii) evaluate the redistribution of SOC stock in soil profile in relation to soil resilience. The continuous CT decreased the SOC stock by 0·58 and 0·67 Mg C ha⁻¹ y⁻¹ in the 0‐ to 20‐cm depth at the PG and LRV sites, respectively, and the rate of SOC sequestration was 0·59 for the PG site and ranged from 0·48 to 1·30 Mg C ha⁻¹ y⁻¹ for the LRV site. The fraction of C input by crop residues converted into SOC stock was ~14·2% at the PG site and ~20·5% at the LRV site. The SOC resilience index ranged from 0·29 to 0·79, and it increased with the increase in the C input among the NT systems and the SOC sequestration rates at the LRV site. These data support the hypothesis that NT cropping systems with high C input have a large potential to reverse the process of soil degradation and SOC decline. Copyright © 2013 John Wiley & Sons, Ltd.     

温度对大叶桃花心木(Swietenia macrophylla King)幼苗叶片的光合影响

本文研究了大叶桃花心木（Swietenia macrophylla King）一年生幼苗在经过夜温处理后的光响应曲线和在饱和光强下的CO2反应曲线.结果表明:在大气CO2浓度下,叶片的最佳光合作用温度在25-31℃之间,而在饱和CO2浓度下为31-35℃.在25℃以下光合速率开始降低,主要是由于羧化效率的降低,而当温度超过31℃时,光合速率下降,是因为羧化效率的降低和呼吸速率的增加.CO2浓度对光合的促进作用在低温下受到抑制,这意味着未来在CO2浓度增高的情况下,高浓度的CO2对热带常绿植物光合的促进在冬天低温情况下表现不十分明显.图4参23.     

Seasonal Biomass Accumulation and Nutrient Uptake of Pea and Lentil on a Black Chernozem Soil in Saskatchewan

ABSTRACT

Close relationships usually exist among biomass accumulation, nutrient uptake, and seed yield during the growing season. Field experiments with pea (Pisum sativum L.) and lentil (Lens cultinaris L.) were conducted in 1998 and 1999 at Melfort, Saskatchewan, Canada, to determine relationships of biomass accumulation and nutrient uptake with days after emergence (DAE) or growing degree days (GDD). For both biomass accumulation and nutrient uptake, maximum rates and amounts increased with time at early growth stages and reached a maximum value at late growth stages. The R² values for cubic polynomial regressions were highly significant, indicating their suitability to estimate the progression of biomass accumulation and nutrient uptake as a function of days after emergence (DAE). Both pulse crops followed a similar pattern in biomass accumulation and nutrient uptake, which increased in the early growth stages and reached a maximum late in the growth cycle. Pulse crops usually reached their maximum biomass accumulation rate and amount at early to late bud formation (42–56 DAE or 390–577 GDD) and at medium pod formation to early seed filling (75–82 DAE or 848–858 GDD) growth stages, respectively. Maximum biomass accumulation rate was 175–215 kg ha^{? 1}d^?1 for pea and 109–140 kg ha^{? 1}d^{? 1} for lentil. Maximum nutrient uptake rate and amount usually occurred at branching to early bud formation (28–49 DAE or 206–498 GDD) and at the flowering to seed filling (66–85 DAE or 672–986 GDD) growth stages, respectively. Maximum uptake rate of nitrogen (N), phosphorus (P), potassium (K), and sulfur (S), respectively, was 4.6–4.9, 0.4–0.5, 5.0–5.3 and 0.3 kg ha^{? 1}d^{? 1} for pea, and 2.4–3.8, 0.2–0.3, 2.0–3.4 and 0.2 kg ha^{? 1}d^{? 1} for lentil. In general, maximum nutrient uptake rate and amount occurred earlier than maximum biomass accumulation rate and amount, respectively; and the maximum accumulation rates of both biomass and nutrients occurred earlier than maximum amounts. The findings suggest that adequate supply of nutrients from soil and fertilizers at early growth stages, and translocation of biomass and nutrients to seed at later growth stages are of great importance for high seed yield of pulse crops.     

Differentially expressed genes identified through RNA‐seq with extreme values of principal components for beef fatty acid in Nelore cattle

The aim of this study was to identify differentially expressed genes (DEG) in the Longissimus thoracis muscle of Nelore cattle related to fatty acid (FA) profile through RNA sequencing and principal component analysis (PCA). Two groups of 10 animals each were selected containing PC1 and PC2 extreme DEG values (HIGH × LOW) for each FA group. The intramuscular fat (IMF) was compared between cluster groups by ANOVA, and only the sum of monounsaturated FA (MUFA) and ω3 showed significant differences (p < .05). Interestingly, the highest percentage (95%) of phenotypic variation explained by the sum of the first two PC was observed for ω3, which also displayed the lowest number of DEG (n = 1). The lowest percentage (59%) was observed for MUFA, which also revealed the largest number of DEG (n = 66). Since only MUFA and ω3 exhibited significant differences between cluster groups, we can conclude that the differences observed for the remaining groups are not due to the percentage of IMF. Several genes that have been previously associated with meat quality and FA traits were identified as DEG in this study. The functional analysis revealed one KEGG pathway and eight GO terms as significant (p < .05), in which we highlighted the purine metabolism, glycolytic process, adenosine triphosphate binding and bone development. These results strongly contribute to the knowledge of the biological mechanisms involved in meat FA profile of Nelore cattle.     

Nature conservation in Spain: A brief account

The history of nature conservation in Spain is reviewed with reference to public attitudes past, present and future. The eight National Parks are listed and described in terns of their location, date of foundation, extension and main historical, floristic and faunistic characteristics.The various other types of reserve and their aims and functions are alluded to and the significance of the role played by ICONA (National Institute for the Conservation of Nature) through the declaration and administration of these vast areas is stressed.Ample comment is made on the deficiency of past and current legislation and hope is expressed in connection with the May 1975 Law for the Creation and Conservation of Protected Natural Spaces.     

Doubled-haploid versus single-seed descent and S1-family variation for testcross performance in a maize population

Progress made in the in situ gynogenesis technique since 1990 now allows production of a high number of maize (Zea mays L.) doubled-haploid (DH) lines. The aim of the study was to compare DH lines versus selfing lines for testcross performance. DH and single-seed descent (SSD) lines were produced from random S₁ progenies of a broad-base population. For grain yield, kernel moisture, plant height, ear height and leaf length, the three population means were similar. Except for kernel moisture, the genetic variance of DH lines was nearly twice as high as the genetic variance of S₁ families, as expected. On the other hand, genetic variance among SSD lines was only 1.5 times higher than the genetic variance of S₁ families. This lower variance could be due to a selection bias in the method of production of SSD lines. However, for all traits, heritability of SSD or DH lines was higher than heritability of S₁ families. Epistasis effects in DH progenies were not significant. The consequence was a high correlation between S₁ testcross progenies and DH or SSD testcross progenies, meaning that the S₁ testcross value can be used to select the best families from which DH lines will be extracted. As a whole, the observed variation in DH lines appeared to be more in accordance with the observed variation among S₁ families than with the observed variation among SSD lines.     

Alginate Microsphere Encapsulation of Drug-Loaded Nanoparticles: A Novel Strategy for Intraperitoneal Drug Delivery

Alginate hydrogels have been broadly investigated for use in medical applications due to their biocompatibility and the possibility to encapsulate cells, proteins, and drugs. In the treatment of peritoneal metastasis, rapid drug clearance from the peritoneal cavity is a major challenge. Aiming to delay drug absorption and reduce toxic side effects, cabazitaxel (CAB)-loaded poly(alkyl cyanoacrylate) (PACA) nanoparticles were encapsulated in alginate microspheres. The PACAlg alginate microspheres were synthesized by electrostatic droplet generation and the physicochemical properties, stability, drug release kinetics, and mesothelial cytotoxicity were analyzed before biodistribution and therapeutic efficacy were studied in mice. The 450 µm microspheres were stable at in vivo conditions for at least 21 days after intraperitoneal implantation in mice, and distributed evenly throughout the peritoneal cavity without aggregation or adhesion. The nanoparticles were stably retained in the alginate microspheres, and nanoparticle toxicity to mesothelial cells was reduced, while the therapeutic efficacy of free CAB was maintained or improved in vivo. Altogether, this work presents the alginate encapsulation of drug-loaded nanoparticles as a promising novel strategy for the treatment of peritoneal metastasis that can improve the therapeutic ratio between toxicity and therapeutic efficacy.