Semen cryopreservation in golden‐headed lion tamarin,Leontopithecus chrysomelas

Wild animal genetic resource banking (GRB) represents a valuable tool in conservation breeding programs, particularly in cases involving endangered species such as the golden‐headed lion tamarin (Leontopithecus chrysomelas). Thus, we aimed to assess a sperm freezing protocol for golden‐headed lion tamarins using two different exenders: BotuBOV® (BB) and Test Yolk Buffer® (TYB). Ejaculates were collected by penile vibrostimulation from animals housed at São Paulo Zoological Park Foundation, São Paulo, Brazil, and after immediate analysis, two aliquots were diluted in BB and TYB. Postthawing samples were evaluated for total and progressive motility, plasma membrane and acrosome integrities, mitochondrial activity, susceptibility to oxidative stress, and sperm–egg‐binding. No differences between BB and TYB were found for most seminal parameters, except for acrosome integrity and susceptibility to oxidative stress (in both cases BB showed higher values). However, in spite of these differences and regardless of the extender used, postthaw sperm motility and viability with the described protocol were encouraging (on average >50% and >80%, respectively), indicating that sperm cryopreservation may be a short‐term measure for the conservation of golden‐headed lion tamarins.     

Segregation of infectious pancreatic necrosis resistance QTL in the early life cycle of Atlantic Salmon (Salmo salar)

In a previous study, three significant quantitative trait loci (QTL) associated with resistance to Infectious Pancreatic Necrosis (IPN) disease were identified by analysing challenge data from one sub-population of Landcatch Atlantic salmon (Salmo salar) smolt. While these QTL were shown to affect the resistance in seawater, their effect in freshwater was unknown. This study investigates the effect of these QTL on IPN resistance in salmon fry in freshwater. Twenty families with intermediate levels of IPN mortality were analysed from a freshwater challenge trial undertaken on a different sup-population of LNS salmon to that studied previously. Only the QTL from linkage group 21 (LG21) appeared to have a significant and large effect on resistance in freshwater; the same QTL was found to have the largest effect in seawater in the previous study. Variance component analysis showed a high heritability for the QTL: 0.45 ± 0.07 on the liability scale and 0.25 ± 0.05 on the observed scale. In a family where both parents were segregating for the QTL, there was a 0% vs. 100% mortality in homozygous offspring for resistant and susceptible QTL alleles. The finding that the same QTL has major effect in both freshwater and seawater has important practical implications, as this will allow the improvement of resistance in both phases through marker assisted selection by targeting this QTL. Moreover, the segregation of the LG21 QTL in a different sub-population gives further evidence of its association with IPN-resistance.     

Investigation of assisted fertilization and biology of reproduction by sperm microinjection

Recent success in assisted fertilization mainly depended on the development of sperm microinjection methods: intracytoplasmic sperm injection and subzonal insemination. Some basic mechanisms that under-lie fertilization were revealed by using intracytoplasmic sperm injection. In respect to this, problems of fertility, oocyte activation, formation of pronuclei and practical aspects of intracytoplasmic sperm injection are discussed.     

Tactile perception and manual dexterity in computer users

Recent studies suggest that sensory input generated during highly repetitive tasks can degrade the sensory representation of the hand and eventually lead to sensory and motor problems. In this study, we investigated whether early changes in tactile perception and manual dexterity could be detected in persons exposed to computer tasks. Performance in tests designed to assess tactile perception (grating orientation task for spatial acuity and roughness discrimination) and manual dexterity (grooved pegboard test) was compared between two groups of healthy individuals, matched for age, gender, and experience, who differed in terms of computer habits. One group consisted of frequent users (FU, > 2 h/day, n = 36) and the other of non or occasional users (OU, < 2 h/day, n = 28). Comparison of performance between groups with subjects sorted by gender revealed significant differences ( t -test, p < 0.05) in female, but not male, participants. Grating resolution thresholds at the tip on the second and fifth digits were, on average, 40% higher in female FU ( n = 13) than in female OU ( n = 10) and performance scores on the dexterity test were significantly higher for the left hand. The results of this study indicate that early signs of deterioration in hand function can be present in persons constantly exposed to computer tasks and that these signs are more readily apparent in women than in men. The loss of tactile spatial acuity found in female FU possibly reflect an early consequence of the degraded sensory representation of the hand resulting from constant repetitions of fine motor tasks.     

Optimizing purebred selection for crossbred performance using QTL with different degrees of dominance

A method was developed to optimize simultaneous selection for a quantitative trait with a known QTL within a male and a female line to maximize crossbred performance from a two-way cross. Strategies to maximize cumulative discounted response in crossbred performance over ten generations were derived by optimizing weights in an index of a QTL and phenotype. Strategies were compared to selection on purebred phenotype. Extra responses were limited for QTL with additive and partial dominance effects, but substantial for QTL with over-dominance, for which optimal QTL selection resulted in differential selection in male and female lines to increase the frequency of heterozygotes and polygenic responses. For over-dominant QTL, maximization of crossbred performance one generation at a time resulted in similar responses as optimization across all generations and simultaneous optimal selection in a male and female line resulted in greater response than optimal selection within a single line without crossbreeding. Results show that strategic use of information on over-dominant QTL can enhance crossbred performance without crossbred testing.     

Assisted Suicide in Switzerland: Clarifying Liberties and Claims

Assisting suicide is legal in Switzerland if it is offered without selfish motive to a person with decision‐making capacity. Although the ‘Swiss model’ for suicide assistance has been extensively described in the literature, the formally and informally protected liberties and claims of assistors and recipients of suicide assistance in Switzerland are incompletely captured in the literature. In this article, we describe the package of rights involved in the ‘Swiss model’ using the framework of Hohfeldian rights as modified by Wenar. After outlining this framework, we dissect the rights involved in suicide assistance in Switzerland, and compare it with the situation in England and Germany. Based on this approach, we conclude that in Switzerland, claim rights exist for those requesting suicide assistance, and for those who are considering providing such assistance, even though no entitlements exist toward suicide assistance. We then describe the implementation of the ‘Swiss model’ and difficulties arising within it. Clarifying these issues is important to understand the Swiss situation, to evaluate what features of it may or may not be worth correcting or emulating, and to understand how it can impact requests for suicide assistance in other countries due to ‘suicide tourism’. It is also important to understand exactly what sets Switzerland apart from other countries with different legislations regarding suicide assistance.     

Developing novel hCT derived cell-penetrating peptides with improved metabolic stability

Many promising therapeutics are currently awaiting their clinical application. Due to their low capability of cell membrane crossing, these compounds do not reach their site of action. One way to overcome this problem might be the fusion of these agents to cell-penetrating peptides (CPP), which are able to shuttle various cargoes across cellular membranes. One disadvantage in using CPP in drug delivery is their low metabolic stability. The aim of our work was to increase the proteolytic resistance of the CPP hCT(9-32), a truncated C-terminal fragment of human calcitonin. Thus, we synthesised six modified N-terminally carboxyfluorescein labelled hCT(9-32) derivatives by replacing positions 12 and/or 16 of hCT(9-32) with either N-methylphenylalanine or d-phenylalanine, respectively. By using confocal laser scanning microscopy we showed that the modifications did neither affect the peptide internalisation efficiency in HeLa nor HEK 293T cells. The metabolic stability of the peptides was investigated in human blood plasma and HEK 293T cell culture supernatant. To analyse the degradation patterns, we used RP-HPLC and MALDI-TOF mass spectrometry. However, we found for all of the new derivatives high metabolic stabilities. In blood plasma, the half-lives for five of the six peptides increased compared to unmodified hCT(9-32). The degradation patterns showed a distinct stabilisation in the N-terminal part of the modified peptides, in the C-terminal part, we found some cleavage to a minor extent. Furthermore, we studied the conformation of the peptides by CD spectroscopy and demonstrated that they possess no cell toxicity. Since our metabolically more stable compounds are still able to pass the cell membrane they provide powerful tools as drug delivery vectors.     

基于运动捕捉残疾人计算机辅助系统的尝试

计算机在当代社会已经被普遍应用。为了帮助肢体残疾人使用计算机,本课题组进行了开发基于脑部跟踪的残疾人计算机辅助系统的尝试,初步制作成功了一种能通过三维脑部运动捕捉人脑运动轨迹、以此控制虚拟鼠标完成几个简单动作的残疾人计算机辅助系统,通过训练后可根据脑部的运动操纵计算机。本系统较之单纯利用脑电的脑-机接口有高得多的识别效率,理论上可基本消除误操作,是一项非常有价值的可望能应用于残疾人的计算机辅助系统的尝试。     

Marker assisted breeding for transformability in maize

Corn lines with improved culturability and transformability were produced using Marker Assisted Breeding (MAB) to introgress specific regions from the highly transformable hybrid, Hi-II, into the elite line, FBLL that responds very poorly in culture. FBLL is a female inbred parental stiff-stalk line that has been used to produce a series of some of DEKALB’s historically best selling hybrids. Five unlinked regions important for culturability and transformability were identified by segregation distortion analysis and introgressed into FBLL to produce the highly transformable FBLL-MAB lines. Agrobacterium mediated transformation was used to screen the FBLL-MAB lines and select the most efficient lines for transformation using immature embryo explants. Two highly efficient transformation systems were developed using kanamycin and glyphosate as selective agents. To evaluate agronomics, two testcross hybrids were produced for each of the three lead FBLL-MAB lines. A 25-location, 3-replication yield trial was used to evaluate grain yield, yield stability, and agronomic characteristics of the hybrids. Yields were found to be 2–5% lower and more stable (across a diverse set of environments) among hybrids produced with the FBLL-MAB lines as compared to the same hybrids produced with FBLL.