Changes in the genetic level and the effects of age at first calving and milk production on survival during the first lactation over the last 25 years

Survival during the first year after first calving was investigated over the last 25 years, 1989–2013, as well as how the association of survival with season of calving, age at first calving (AFC) and within-herd production level has changed over that period. The data set contained 1 108 745 Dutch black-and-white cows in 2185 herds. Linear models were used to estimate (1) effect of year and season and their interaction and (2) effect of AFC, within-herd production level, and 5-year intervals and their two-way interactions, and the genetic trend. All models contained AFC and percentage of Holstein Friesian as a fixed effect, and herd-year-season, sire and maternal grandsire as random effects. Survival and functional survival were analysed. Functional survival was defined as survival adjusted for within-herd production level. Survival rate increased by 8% up to 92% in the last 25 years. When accounting for pedigree, survival showed no improvement up to 1999, but improved since then. Genetically, survival increased 3% to 4% but functional survival did not increase over the 25 years. We found an interesting difference between the genetic trends for survival and functional survival for bulls born between 1985 and 1999, where the trend for survival was still increasing, but was negative for functional survival. Since 1999, genetic trend picked up again for both survival and functional survival. AFC, season of calving and within-herd production level affected survival. Survival rate decreased 0.6%/month for survival and 1.5% for functional survival between AFC of 24 and 32 months. Calving in summer resulted in 2.0% higher survival than calving in winter. Within herd, low-producing cows had a lower survival rate than high-producing cows. However, these effects became less important during the recent years. Based on survival optimum AFC is around 24 months, but based on functional survival it is better to have an AFC<24 months. Overall, survival rate of heifers has improved considerably in the past 25 years, initially due to the focus on a high milk production. More recently, the importance of a high milk production has been reduced towards attention for functional survival.     

120 例初治、年轻、中高/ 高危弥漫大B细胞淋巴瘤的临床分析

目的:探讨初治、年轻、中高/高危弥漫大B细胞淋巴瘤(diffuse large B cell lymphoma,DLBCL)的临床特征、治疗措施及预后影响因素。方法:回顾性分析2006年1月至2014年5月军事医学科学院附属医院淋巴瘤科收治的年龄≤60岁、年龄调整的国际预后指数(aa IPI)评分≥2分的初治DLBCL病例,进行疗效及预后相关因素的分析。结果:共收集到资料完整的DLBCL病例120例,中位随访28(4-106)个月,3年PFS率53.25%,OS率61.52%。单因素分析结果显示B症状、治疗方案及近期疗效、自体移植对无进展生存(PFS)及总体生存(OS)率的影响有统计学意义。多因素分析结果显示治疗方案、自体造血干细胞移植是影响PFS、OS率的独立影响因素。结论:年轻、中高/高危DLBCL具有高度异质性,病理细胞来源、Ki-67等在本组病例中未见显著预后意义,有待临床进一步探索。     

Effects of food abundance and early clutch predation on reproductive timing in a high Arctic shorebird exposed to advancements in arthropod abundance

Climate change may influence the phenology of organisms unequally across trophic levels and thus lead to phenological mismatches between predators and prey. In cases where prey availability peaks before reproducing predators reach maximal prey demand, any negative fitness consequences would selectively favor resynchronization by earlier starts of the reproductive activities of the predators. At a study site in northeast Greenland, over a period of 17 years, the median emergence of the invertebrate prey of Sanderling Calidris alba advanced with 1.27 days per year. Yet, over the same period Sanderling did not advance hatching date. Thus, Sanderlings increasingly hatched after their prey was maximally abundant. Surprisingly, the phenological mismatches did not affect chick growth, but the interaction of the annual width and height of the peak in food abundance did. Chicks grew especially better in years when the food peak was broad. Sanderling clutches were most likely to be depredated early in the season, which should delay reproduction. We propose that high early clutch predation may favor a later reproductive timing. Additionally, our data suggest that in most years food was still abundant after the median date of emergence, which may explain why Sanderlings did not advance breeding along with the advances in arthropod phenology.     

Absence of Mate Choice and Postcopulatory Benefits in a Species with Extreme Sexual Size Dimorphism

Most hypotheses related to the evolution of female‐biased extreme sexual size dimorphism (SSD) attribute the differences in the size of each sex to selection for reproduction, either through selection for increased female fecundity or selection for male increased mobility and faster development. Very few studies, however, have tested for direct fitness benefits associated with the latter – small male size. Mecaphesa celer is a crab spider with extreme SSD, whose males are less than half the size of females and often weigh 10 times less. Here, we test the hypotheses that larger size in females and smaller size in males are sexually selected through differential pre‐ and postcopulatory reproductive benefits. To do so, we tested the following predictions: matings between small males and large females are more likely to occur due to mate choice; females mated to small males are less likely to accept second copulation attempts; and matings between small males and large females will result in larger clutches of longer‐lived offspring. Following staged mating trials in the laboratory, we found no support for any of our predictions, suggesting that SSD in M. celer may not be driven by pre‐ or post‐reproductive fitness benefits to small males.     

Differential effect of shade,water and soil type on emergence and early survival of three dominant species of the Atacama Desert

Understanding the regeneration niche of species may allow us to gain insight into how communities are structured. In deserts, the regeneration niche is usually related to spaces beneath shrubs where shade cast by shrubs creates microenvironments that benefit seedlings and where even small amounts of rain may favour germination and establishment. Shade and water may also interact with different types of soils. However, species may have different requirements for germination and seedling survival. We could expect that shrub species with different drought tolerances exhibit different responses to the combination of these factors. We ask if responses of dominant species of the Atacama Desert to abiotic factors (shade, water and soil type) are related to their drought tolerance, a topic not exhaustively explored in shrubs growing in true deserts. We conducted two factorial experiments. The first one was designed to evaluate how shade (microhabitat) in combination with water may affect germination (emergence) and early survival. In the second experiment, we assessed the influence of shade in relation to soil type. Each species responded distinctively to the three variables under study, but in general, their emergence responses were more influenced by water (more water, greater emergence) than by microhabitat or soil type. Survival was influenced both by microhabitat and by water and was higher under shade and abundant water. Soil type affected only one of our species in terms of emergence. Species responses in general depended on their tolerance to stress. In one species, there was indication of a seed–seedling conflict. Our results show similar species responses to environmental constraints but also more or less unique responses that are related to their tolerance to drought and which may ultimately permit species coexistence. We found that shade may not be important for germination but may be crucial for survival in dry years.     

Coupling spatial segregation with synthetic circuits to control bacterial survival

Engineered bacteria have great potential for medical and environmental applications. Fulfilling this potential requires controllability over engineered behaviors and scalability of the engineered systems. Here, we present a platform technology, microbial swarmbot, which employs spatial arrangement to control the growth dynamics of engineered bacteria. As a proof of principle, we demonstrated a safeguard strategy to prevent unintended bacterial proliferation. In particular, we adopted several synthetic gene circuits to program collective survival in Escherichia coli: the engineered bacteria could only survive when present at sufficiently high population densities. When encapsulated by permeable membranes, these bacteria can sense the local environment and respond accordingly. The cells inside the microbial swarmbot capsules will survive due to their high densities. Those escaping from a capsule, however, will be killed due to a decrease in their densities. We demonstrate that this design concept is modular and readily generalizable. Our work lays the foundation for engineering integrated and programmable control of hybrid biological–material systems for diverse applications.     

Characterization of the binding of paylean and DNA by fluorescence,UV spectroscopy and molecular docking techniques

The interaction of paylean (PL) with calf thymus DNA (ctDNA) was investigated using fluorescence spectroscopy, UV absorption, melting studies, ionic strength, viscosity experiments and molecular docking under simulated physiological conditions. Values for the binding constant K_a between PL and DNA were 5.11 × 10³, 2.74 × 10³ and 1.74 × 10³ L mol^–1 at 19, 29 and 39°C respectively. DNA quenched the intrinsic fluorescence of PL via a static quenching procedure as shown from Stern–Volmer plots. The relative viscosity and the melting temperature of DNA were basically unchanged in the presence of PL. The fluorescence intensity of PL–DNA decreased with increasing ionic strength. The value of K_a for PL with double‐stranded DNA (dsDNA) was larger than that for PL with single‐stranded DNA (ssDNA). All the results revealed that the binding mode was groove binding, and molecular docking further indicated that PL was preferentially bonded to A–T‐rich regions of DNA. The values for ΔH, ΔS and ΔG suggested that van der Waals forces or hydrogen bonding might be the main acting forces between PL and DNA. The binding distance was determined to be 3.37 nm based on the theory of Förster energy transference, which indicated that a non‐radiation energy transfer process occurred. Copyright © 2015 John Wiley & Sons, Ltd.     

HPV+/-宫颈癌患者临床特点与预后的对比分析

目的:探讨HPV阴性与HPV阳性宫颈癌的临床特点及其和预后的关系。方法:选取住院手术的HPV呈阴性与阳性的宫颈癌患者各86例,且两组患者在年龄、FIGO临床分期相近。分析两组患者的年龄、肿瘤临床分期、病理分型、原发肿瘤大小、分化程度、基层浸润深度、淋巴结转移、治疗方案情况及其5年RFS和总生存时间。结果:两组间宫颈癌患者肿瘤分化程度、肌层浸润深度、淋巴结转移间差异有统计学意义(P0.05)。HPV阳性组和HPV阴性组随访时间分别为63(13~87)个月、61(9~90)个月,5年总生存率分别为70.4%和61.3%,平均总生存时间分别为(73.15±2.74)月和(62.72±3.03)月,差异有统计学意义(p0.05)。HPV阴性组和HPV阳性组5年RFS分别为52.3%和66.4%,平均RFS为(51.57±4.62)月和(58.83±3.46)月,差异有统计学意义(p0.05)。结论:HPV阴性宫颈癌瘤体倾向于低分化,易发生局部侵犯和淋巴结转移,其临床预后较差。