The effects of migration on the immunity of Black-Headed Gulls (Chroicocephalus ridibundus: Laridae)

In order to elucidate the relationship between migration period and immunity related to susceptibility, we conducted research on Black-headed gulls (Chroicocephalus ridibundus). We captured 260 gulls and collected their peripheral blood. Their leukocyte (WBC) count, percentages of heterophils (Het) and lymphocytes (Lym), heterophil and lymphocyte ratio (H/L ratio), and CD4 and CD8α expression levels (CD4 and CD8α, respectively) were quantitatively analyzed over three migration periods (Autumn migration, Wintering, Spring migration). In Adult gulls, WBC counts and CD4 levels significantly increased. Moreover, the Het and H/L ratio decreased from the Autumn migration to Wintering. Conversely, only WBC counts and CD4 levels measurements significantly decreased from Wintering to Spring migration (P<0.05). The tested parameters of the Tokyo-bay population show a greater significant difference than the measurements of immunity of the Mikawa-bay population. This study suggests that the migratory period has a negative effect on an aspect of the immune system. Including the period-difference in the immune systems in the local population, it is necessary to investigate the relationship between the ecology of migratory birds and their immunity.     

An insertion/deletion variant of a thymine base in exon 2 of the porcine beta 3‐adrenergic receptor gene associated with loin eye muscle area

An insertion/deletion variant of a thymine base (T5 and T6) in exon 2 of porcine beta 3‐adrenergic receptor (ADRB3) gene has been described. In the current study, we made an association study between the ADRB3 polymorphisms and production traits in 735 Duroc pigs. The allele frequencies for the T5 and T6 alleles in our study population were 0.433 and 0.567, respectively. Any associations between ADRB3 genotype and average daily weight gain during test period, or backfat thickness and intramuscular fat content were not detected in either sex. However the size of the loin eye muscle area (EMA) was significantly associated with ADRB3 genotypes in gilts. T6‐homozygous gilts had a higher mean of EMA (40.6 ± 0.6 cm²) than T5‐homozygous (38.1 ± 0.4 cm², P = 0.002) and heterozygous (38.8 ± 0.3 cm², P = 0.034) gilts. This association was not detected in males. In addition, a multiple traits animal model best linear unbiased predictor (BLUP) analysis revealed that the T6‐homozygous genotype had positive effects on breeding value of EMA. Accordingly, we suggest that ADRB3 polymorphism has the potential to be an important genetic marker for prediction of EMA in Duroc pigs.     

Flight distance of dairy cows and its relationship to daily routine management procedures and productivity

The objectives of this study were to determine to what extent the flight distance of cows to humans was influenced by sire and management procedures before and after maturity, and whether there was a correlation between the flight distance and productivity on commercial dairy farms. Flight distance of 84 Holstein cows, the stockperson's daily routine management procedures and production performance were recorded repeatedly on eight commercial dairy farms. The management procedures for the animals at the suckling, growing, lactating and dry stages were classified into four categories by degree of tactile interactions between the stockperson and the animal: hand procedures with touch on (category A), nearby (category B) and apart (category C) from the animal, and machinery procedures (category D). There was no apparent sire effect on flight distance ( P  = 0.08), whereas the flight distance ranged from 1.17 ± 0.86 to 4.47 ± 2.01 m by farm ( P  < 0.01), and gradually shortened with repetition ( P  < 0.05). Regression analysis indicated that the length of time of category B at the suckling stage and category B at the dry stage accounted for 37% and 32% of the variation in flight distance, respectively. As for the total time of the four procedure categories, growing stage was the prime predictor of flight distance, which accounted for 36% of the variation. Flight distance tended to correlate with the first calving age ( r  = 0.66, P  = 0.07). These results suggest the importance of non-producing periods, before maturity and during the dry period, on the subsequent and lifelong advantages of a good relationship between the stockperson and their animals.     

草莓果实含水量对品质的影响

将土壤水分控制在不同水平，获得了130个不同含水量的果实，分析表明：随着果实含水量的减少，果实大小、滴定酸含量降低，可溶性总糖、糖酸比、色相和硬度增加。在提高糖含量的过程中，蔗糖、葡萄糖和果糖提高的幅度并不一样，从而改变了3种单糖占可溶性总糖的比例，果实含水量与果实Brix、糖酸比的相关系数为－0.71和－0.61。     

管网安全性水力评价指标的研究

针对日本国正在运行的绫川地区管网的事故 (漏水 )情况 ,从水力学角度分析了事故频度与管道加权平均流速、最大及最小水压积算值比值、安全率、平均最大及最小水压、最大水锤压积算值比值等因素的关系 ,得出影响系统安全的主要水力学因素有负压、最大水压积算值比率、安全率。对于均匀坡度的管道系统 ,安全率是评价系统水力安全性的重要指标。