Is alternate wetting and drying irrigation technique enough to reduce methane emission from a tropical rice paddy?

Combination of a pre-season wet soil condition and rice straw incorporation just before transplanting, which is typical for a tropical rice double cropping, can induce a flash of methane (CH₄) emission shortly after the transplanting. The conventional practice of alternate wetting and drying (AWD) irrigation technique that typically starts at 21 days after transplanting (DAT) can hardly reduce this emission because the soil become methanogenic before the onset of AWD treatment. Field experiments were conducted in Central Luzon, Philippines, during the 2014–2017 dry rice seasons to examine the effects of the timing of rice straw/stubble incorporation on the efficacy of AWD in reducing the CH₄ emission. Two treatments of the timing of stubble incorporation were stubbles incorporated during the start of wet land preparation (S1) and stubbles incorporated during the dry fallow tillage (S2). For the water management, we compared two treatments: continuous flooding (CF) and AWD with – 15 cm threshold for irrigation. The AWD under S2 was implemented earlier at 10 DAT. We observed a significant interaction (p < 0.01) between effects of AWD and straw management on CH₄ emissions; the seasonal total CH₄ emission was reduced by AWD compared with CF by 73% under S2, while the reduction was <20% under S1. The AWD significantly (p < 0.05) increased the nitrous oxide (N₂O) emissions by 47 and 48% relative to CF under S1 and S2, respectively. The global warming potential (GWP, CH₄ + N₂O) and yield-scaled GWP were still substantially lower by 62 and 59%, respectively, in AWD than in CF under S2, but the reduction was not realized under S1 due to the relatively smaller CH₄ reduction and increased N₂O emission. The results confirm that pre-season aerobic stubble decomposition and earlier implementation of AWD enhanced AWD’s mitigation potential in reducing substantially the CH₄ emission from the tropical rice double-cropping system.     

Changes in the soil C and N contents,C decomposition and N mineralization potentials in a rice paddy after long-term application of inorganic fertilizers and organic matter

A long-term experiment on combined inorganic fertilizers and organic matter in paddy rice (Oryza sativa L.) cultivation began in May 1982 in Yamagata, northeastern Japan. In 2012, after the 31^st harvest, soil samples were collected from five fertilizer treatments [(1) PK, (2) NPK, (3) NPK + 6 Mg ha^?1 rice straw (RS), (4) NPK + 10 Mg ha^?1 rice straw compost (CM1), and (5) NPK + 30 Mg ha^?1 rice straw compost (CM3)], at five soil depths (0–5, 5–10, 10–15, 15–20 and 20–25 cm), to assess the changes in soil organic carbon (SOC) content and carbon (C) decomposition potential, total nitrogen (TN) content and nitrogen (N) mineralization potential resulting from long-term organic matter addition. The C decomposition potential was assessed based on the methane (CH₄) and carbon dioxide (CO₂) produced, while the N mineralization potential was determined from the potassium chloride (KCl)-extractable ammonium-nitrogen (NH₄⁺-N), after 2, 4, 6 and 8 weeks of anaerobic incubation at 30°C in the laboratory. Compared to NPK treatment, SOC in the total 0–25 cm layer increased by 67.3, 21.0 and10.8%, and TN increased by 64.2, 19.7 and 10.6%, in CM3, RS and CM1, respectively, and SOC and TN showed a slight reduction in the PK treatment by 5.2 and 5.7%, respectively. Applying rice straw compost (10 Mg ha^?1) instead of rice straw (6 Mg ha^?1) to rice paddies reduced methane production by about 19% after the soils were measured under 8 weeks of anaerobic incubation at 30°C. Soil carbon decomposition potential (Co) and nitrogen mineralization potential (No) were highly correlated with the SOC and TN contents. The mean ratio of Co/No was 4.49, lower than the mean ratio of SOC/TN (13.49) for all treatments, which indicated that the easily decomposed organic matter was from soil microbial biomass and soil proteins.     

Exposure to the Neurotoxic Dinoflagellate,Alexandrium catenella,Induces Apoptosis of the Hemocytes of the Oyster,Crassostrea gigas

This study assessed the apoptotic process occurring in the hemocytes of the Pacific oyster, Crassostrea gigas, exposed to Alexandrium catenella, a paralytic shellfish toxins (PSTs) producer. Oysters were experimentally exposed during 48 h to the toxic algae. PSTs accumulation, the expression of 12 key apoptotic-related genes, as well as the variation of the number of hemocytes in apoptosis was measured at time intervals during the experiment. Results show a significant increase of the number of hemocytes in apoptosis after 29 h of exposure. Two pro-apoptotic genes (Bax and Bax-like) implicated in the mitochondrial pathway were significantly upregulated at 21 h followed by the overexpression of two caspase executor genes (caspase-3 and caspase-7) at 29 h, suggesting that the intrinsic pathway was activated. No modulation of the expression of genes implicated in the cell signaling Fas-Associated protein with Death Domain (FADD) and initiation-phase (caspase-2) was observed, suggesting that only the extrinsic pathway was not activated. Moreover, the clear time-dependent upregulation of five (Bcl2, BI-1, IAP1, IAP7B and Hsp70) inhibitors of apoptosis-related genes associated with the return to the initial number of hemocytes in apoptosis at 48 h of exposure suggests the involvement of strong regulatory mechanisms of apoptosis occurring in the hemocytes of the Pacific oyster.     

Occurrence, clinical features and outcome of canine pancreatitis (80 cases)

Medical records of 80 dogs diagnosed with acute pancreatitis during a 4-year period were evaluated regarding history, breed predilection, clinical signs and additional examination findings. Cases were selected if compatible clinical symptoms, increased serum activity of amylase or lipase and morphologic evidence of pancreatitis by ultrasonography, laparotomy or necropsy were all present. Like in other studies, neutered dogs had an increased risk of developing acute pancreatitis. Although breed predilection was consistent with earlier reports, some notable differences were also observed. Apart from Dachshunds, Poodles, Cocker Spaniels and Fox Terriers, the sled dogs (Laikas, Alaskan Malamutes) also demonstrated a higher risk for pancreatitis according to our results. Concurrent diseases occurred in 56 dogs (70%), diabetes mellitus (n = 29, 36%) being the most common. Clinical signs of acute pancreatitis were similar to those observed in other studies. The study group represented a dog population with severe acute pancreatitis, having a relatively high mortality rate (40%) compared to data of the literature. Breed, age, gender, neutering and body condition had no significant association with the outcome. Hypothermia (p = 0.0413) and metabolic acidosis (p = 0.0063) correlated significantly with poor prognosis and may serve as valuable markers for severity assessment in canine acute pancreatitis.     

Effects of prolactin receptor genotype on the litter size of Mangalica

The aim of this study was to detect different alleles of the prolactin receptor (PRLR) gene and to examine their effects on the litter size of the indigenous Hungarian pig, the Mangalica. G1789A single nucleotide polymorphism (SNP) was investigated as a candidate for litter size. Samples from 80 purebred Mangalica sows and data of their 335 litters were provided by Olmos & Tóth Ltd. Hair follicles were used to isolate the required DNA. Allelic discrimination was performed by means of the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method using the AluI restriction enzyme and agarose gel electrophoresis. In the population examined, the A allele was found to be preferable in the Mangalica breed group. The most advantageous AA genotype was the least prevalent (8.75%), while the frequencies of AB and BB were 40% and 51.25%, respectively. Remarkably, the average number of piglets born alive per litter was 1.11 ± 0.39 higher in sows with AA as compared to those with BB genotype. By raising the frequency of the AA genotype, the litter size is likely to increase. However, the effect of PRLR genotypes can differ among pig breeds and even lines. Further studies may be required to observe and estimate possible pleiotropic effects of this polymorphism on other traits.     

Infants' perseverative search errors are induced by pragmatic misinterpretation

Having repeatedly retrieved an object from a location, human infants tend to search the same place even when they observe the object being hidden at another location. This perseverative error is usually explained by infants' inability to inhibit a previously rewarded search response or to recall the new location. We show that the tendency to commit this error is substantially reduced (from 81 to 41%) when the object is hidden in front of 10-month-old infants without the experimenter using the communicative cues that normally accompany object hiding in this task. We suggest that this improvement is due to an interpretive bias that normally helps infants learn from demonstrations but misleads them in the context of a hiding game. Our finding provides an alternative theoretical perspective on the nature of infants' perseverative search errors.