Nitrogen use efficiency with the application of controlled release fertilizers coated with Kraft pine lignin

The aim of the present paper is to assess the efficiency of several experimental fertilizers in a soil-plant system. The laboratory-prepared fertilizers consisted of granular urea coated with Kraft pine lignin. Five fertilizers were used with coatings differing in thickness and/or the addition of linseed oil as a sealing agent. The experiment was carried out in pots inside a glasshouse. The crop used was rye-grass. Results were compared with those from a urea control treatment without coating and a soil without fertilizer application.

The dry matter yield and the N uptake by the plant were higher in the treatments with coated controlled release fertilizers (CRF) than in those with uncoated urea. There was a lower nitrogen loss through leaching when using CRF (34 to 68%) was used than when using uncoated urea (over 74%) was used. The N use efficiency was lower for urea than for coated fertilizers. This index increased with the thickness of the coating and the addition of the sealing agent.     

DNA Status on Thawed Semen from Fighting Bull: A Comparison Between the SCD and the SCSA Tests

The assessment of sperm chromatin status is compulsory in a complete spermiogram. Here we applied the sperm chromatin structure assay (SCSA) and the sperm chromatin dispersion (SCD) test to assess the chromatin status of three fighting bulls. Cryopreserved semen (two straws/bull) were analysed by duplicate after thawing and after 6 h at 37°C with and without oxidative stress (1 m m FE²⁺). Results (SCD: percentage of spermatozoa with halo; SCSA: SD-DFI, %DFI and HDS) were analysed for differences between bulls and treatments, sensitivity and specificity (receiver operating characteristic curves) and repeatability (repeatability coefficients as 2SD of duplicate differences).%DFI for the three bulls was below 2% at 0 h, indicating no risk for fertility according to previous reports. It increased slightly for two of the bulls after FE²⁺ treatment (%DFI < 5%) and more pronouncedly for the other bull (C, %DFI∼10%), which merits further investigation. SCD rendered higher percentage of halos for bull C, but could not discriminate between samples with and without oxidizing treatment (AUC: 0.52). SCSA (%DFI) showed a high discriminating ability between treatments (AUC: 0.96). The repeatability coefficient was also higher for SCD (5.9) than for %DFI (1.8), indicating lower repeatability for SCD. Overall, %DFI might be the most useful parameter for assessing sperm chromatin on fighting bull. SCD might yield different information than SCSA, hence further research is warranted.     

Determination of the uptake and translocation of nitrogen applied at different growth stages of a melon crop (Cucumis melo L.) using N isotope

In order to establish a rational nitrogen (N) fertilisation and reduce groundwater contamination, a clearer understanding of the N distribution through the growing season and its dynamics inside the plant is crucial. In two successive years, a melon crop (Cucumis melo L. cv. Sancho) was grown under field conditions to determine the uptake of N fertiliser, applied by means of fertigation at different stages of plant growth, and to follow the translocation of N in the plant using ¹⁵N-labelled N. In 2006, two experiments were carried out. In the first experiment, labelled ¹⁵N fertiliser was supplied at the female-bloom stage and in the second, at the end of fruit ripening. Labelled ¹⁵N fertiliser was made from ¹⁵NH₄¹⁵NO₃ (10 at.% ¹⁵N) and 9.6 kg N ha⁻¹ were applied in each experiment over 6 days (1.6 kg N ha⁻¹ d⁻¹). In 2007, the ¹⁵N treatment consisted of applying 20.4 kg N ha⁻¹ as ¹⁵NH₄¹⁵NO₃ (10 at.% ¹⁵N) in the middle of fruit growth, over 6 days (3.4 kg N ha⁻¹ d⁻¹). In addition, 93 and 95 kg N ha⁻¹ were supplied daily by fertigation as ammonium nitrate in 2006 and 2007, respectively. The results obtained in 2006 suggest that the uptake of N derived from labelled fertiliser by the above-ground parts of the plants was not affected by the time of fertiliser application. At the female-flowering and fruit-ripening stages, the N content derived from ¹⁵N-labelled fertiliser was close to 0.435 g m⁻² (about 45% of the N applied), while in the middle of fruit growth it was 1.45 g m⁻² (71% of the N applied). The N application time affected the amount of N derived from labelled fertiliser that was translocated to the fruits. When the N was supplied later, the N translocation was lower, ranging between 54% at female flowering and 32% at the end of fruit ripening. Approximately 85% of the N translocated came from the leaf when the N was applied at female flowering or in the middle of fruit growth. This value decreased to 72% when the ¹⁵N application was at the end of fruit ripening. The ammonium nitrate became available to the plant between 2 and 2.5 weeks after its application. Although the leaf N uptake varied during the crop cycle, the N absorption rate in the whole plant was linear, suggesting that the melon crop could be fertilised with constant daily N amounts until 2–3 weeks before the last harvest.     

Activation of Mouse Oocytes Following Intracytoplasmic Injection of Chicken Sperm Extract

The cytosolic factor from the sperm of a wide variety of species has been reported to induce [Ca²⁺]i increase and/or activation in oocytes. Although many species have been studied, there is no data available on the chicken sperm factor responsible for activation of oocytes. This study was aimed to verify the activation of mouse oocyte by intracytoplasmic injection of chicken sperm extract (CSE). Survival rate of oocytes without rupture or lytic degeneration following injection was greater than 80% regardless of the presence or absence of CSE. Among the intact oocytes, activation rates following injection were 27.5% (11 of 40) in the sham operation group. Injection of CSE resulted in significantly higher activation rates in the 1/10 dilution group (57.8%, 26 of 45) compared with the sham operation group (p = 0.0045). Calculated amount of injected sperm extract of 1/10 dilution of CSE was equivalent of 12 chicken sperm. When the 1/10 diluted mouse sperm extract (MSE) was injected, survival rate of injected oocytes and activation rate of the survived oocytes was 82% (41 of 50) and 78% (32 of 41), respectively. Activation rate of MSE‐injected oocytes was a little but significantly higher than that of CSE‐injected oocytes (p < 0.037). In conclusion, it suggests that CSE can activate the mouse oocyte and that oocyte activating sperm factor(s) may be common between avian and mammal.     

Effects of Glucose Concentration on in vitro Fertilization in BALB/c Mice

BALB/c mice are widely used in genetic, tumour and immunological studies. However, the mice demonstrate a lower reproduction rate, low fertility and small litters, because of their highly genetic homozygoisty. Based on in vitro fertilization (IVF), a routine technique for biomedical studies, it is worth to evaluate the effects to BALB/c mice on IVF efficiency. In order to test the genetic factor affecting the IVF efficiency of BALB/c, four reciprocal IVF tests of BALB/cByJ and FVB/NCrl mice were performed. The results showed that the average fertility of IVF sponsored by FVB/NCrl spermatozoa was 69.6%, but only 12.1% was obtained from BALB/cByJ strain. Effect of glucose contained in the culture medium to the IVF efficiency of BALB/cByJ was also evaluated. The results showed that the fertility of BALB/cByJ spermatozoa incubated with 0, 2.7, 5.5, 11.1 and 22.2 mm of glucose in the TYH medium were 6.8, 9.9, 13.9, 32.7 and 22.2%, respectively. It is showed that IVF efficiency of BALB/cByJ spermatozoa could be improved depending on the concentration of glucose in the IVF medium. According to the results, it is beleived that lower IVF of BALB/cByJ mice might be due to the genetic defect in spermatozoa and increasing glucose in the IVF medium which significantly affect the IVF efficiency of BALB/cByl via activating the spermatozoa.     

Effect of flushing frequency on emitter clogging in microirrigation with effluents

Flushing is an important maintenance task that removes accumulated particles in microirrigation laterals that can help to reduce clogging problems. The effect of three dripline flushing frequency treatments (no flushing, one flushing at the end of each irrigation period, and a monthly flushing during the irrigation period) was studied in surface and subsurface drip irrigation systems that operated using a wastewater treatment plant effluent for three irrigation periods of 540 h each. The irrigation systems had two different emitters, one pressure compensating and the other not, both molded and welded onto the interior dripline wall, placed in laterals 87 m long. Dripline flow of the pressure compensating emitter increased 8% over time, while in the nonpressure compensating emitter, dripline flow increased 25% in the surface driplines and decreased 3% in the subsurface driplines by the emitter clogging. Emitter clogging was affected primarily by the interactions between emitter location, emitter type, and flushing frequency treatment. The number of completely clogged emitters was affected by the interaction between irrigation system and emitter type. There was an average of 3.7% less totally clogged emitters in flushed surface driplines with the pressure compensating emitter as compared to flushed subsurface laterals with the nonpressure compensating emitter.     

Quebrada jaguay: early south american maritime adaptations

Excavations at Quebrada Jaguay 280 (QJ-280) (16 degrees30'S) in south coastal Peru demonstrated that Paleoindian-age people of the Terminal Pleistocene (about 11,100 to 10,000 carbon-14 years before the present or about 13,000 to 11,000 calibrated years before the present) in South America relied on marine resources while resident on the coast, which extends the South American record of maritime exploitation by a millennium. This site supports recent evidence that Paleoindian-age people had diverse subsistence systems. The presence of obsidian at QJ-280 shows that the inhabitants had contact with the adjacent Andean highlands during the Terminal Pleistocene.     

Effect of filter, emitter and location on clogging when using effluents

The effect on emitter clogging of four filtration systems (sand, screen, disc and a combination of screen and disc filters) and six emitter types placed in laterals 87 m long, using two different effluents with low suspended solid levels from a wastewater treatment plant, was studied for 1000 h. Four of the emitters were molded and welded into dripline wall, two of them being pressure-compensated and the other two non-pressure-compensated. The other two emitters, both pressure-compensated, were inserted into thick wall. Emitter clogging was affected mainly by emitter type, location along the lateral and the interaction between these two factors. Differences among emitters with larger clogging were only observed at the end of dripline. Two molded and welded emitters showed the worst performance: one non-pressure-compensated with the lowest passage section, and the other pressure-compensated that, after 800 h working at higher dripline flow and particle load, experienced an important decrease in flow rate. Only with the effluent that had a higher number of particles, did the filter and the interaction of filter and emitter location have a significant effect. Emitters placed after screen and sand filters showed the largest flow rates at the lateral ending, even though only sand filtration significantly reduced turbidity and suspended solids. Emitters protected by a disc filter experienced the largest flow rate reductions.     

Expression of Occludin in Canine Testis and Epididymis

Tight junctions (TJ) in inter-Sertoli junctional areas and epididymal epithelia are important for the formation of blood-testis barrier (BTB) and blood-epididymal barrier (BEB). In this study, the expression of occludin, an integral member of the TJ, was verified in canine testis and epididymis. Both low molecular weight (MW) (25-28 kDa) forms as well as high MW (68-72 kDa) forms of occludin were detected in the testis and epididymis using Western blot. The relative amount of the high MW forms of occludin vs low MW forms was higher in the testis than in the epididymis. Some difference in the composition of different MW forms of occludin was found along the segments of epididymis, suggesting the possible correlation between cellular composition of occludin proteins and paracellular permeability of epithelia along the epididymal tubule. In the testis, intense occludin immunoreactivity was found in the basally located inter-Sertoli junctional area. Diffused immunoreactivity of occludin was also found in the cytoplasm of Sertoli cells. A similar pattern of zonula occludens-1 immunoreactivity was found in the cytoplasm of Sertoli cells, suggesting that occludin was not confined to the inter-Sertoli junctional areas and that subcellular localization of occludin in the Sertoli cells was dynamically regulated during spermatogenesis in canine testis. In the epididymis weak immunoreactivity was found in the apical sides and cytoplasm of epithelial cells.