The SER Standards: a globally relevant and inclusive tool for improving restoration practice—a reply to Higgs et al.

In response to a critique by Higgs et al., this article clarifies the content and intent of the Society for Ecological Restoration's (SER) International Standards for the Practice of Ecological Restoration. Higgs et al. expressed concern that the SER Standards are not sufficiently underpinned by principles and risk disenfranchising some practitioners by narrowing what qualifies as ecological restoration. To demonstrate that these concerns are unfounded, we discuss the policy context and principles on which the Standards are based, its organizational structure, the innovative and inclusive approach used for development, and highlight significant errata by Higgs et al.     

Design,synthesis and anti-influenza A virus activity of novel 2,4-disubstituted quinazoline derivatives

Four 2,4-disubstituted quinazoline series containing various amide moieties were designed and synthesized as new anti-influenza A virus agents using the strategies of bio-isosterism and scaffold hopping. Many of them exhibit potent in vitro anti-influenza A virus activity and low cytotoxicity (CC₅₀: >100 μM). Particularly, compounds 10a5 and 17a show better activity (IC₅₀: 3.70–4.19 μM) and higher selective index (SI: >27.03, >23.87, respectively) against influenza A/WSN/33 virus (H1N1), opening a new direction for quinazoline derivatives in anti-influenza A virus field.     

Sampling bias in estimating Design II variance components with S1 families

Summary The use of several S₁ individuals to represent an S₀ individual permits the use of a Design II mating scheme for plants with only one pistillate flower per plant. Estimates of additive (V _A ) and dominance (V _D ) variance from this mating scheme will be biased upwards, when a small number (10) of individuals of each S₁ line are used. This bias can be computed, and the additive and dominance estimates can be corrected. Of particular interest is the observation that the additive genetic variance contributes to bias in estimates of V _D . When S₀ plants are non inbred and their selfedprogeny (S₁ lines) are used to represent them in developing families for use in the Design II, where m₁ is the number of individuals used to represent an S₁ line in developing half sib-families and m₂ is the number of individuals used to represent the S₁ line in making up full sib-families. For example, in a 3×3 Design II, with about 10 individuals used to represent each S₁ line in each cross, m₂ = 10 and m₁ = 30. When m₁ = m₂ = 1, and Joint contribution from Department of Agronomy, University of Nebraska 68583, and the S. S. Cameron Laboratory, Werribee, Victoria 3030, Australia. Published as paper No. 7395, Journal Series     

Basic tetrapeptides as potent intracellular inhibitors of type A botulinum neurotoxin protease activity

Botulinum neurotoxins (BoNT) are the most potent of all toxins that cause flaccid muscle paralysis leading to death. They are also potential biothreat agents. A systematic investigation of various short peptide inhibitors of the BoNT protease domain with a 17-residue peptide substrate led to arginine-arginine-glycine-cysteine having a basic tetrapeptide structure as the most potent inhibitor. When assayed in the presence of dithiothreitol (DTT), the inhibitory effect was drastically reduced. Replacing the terminal cysteine with one hydrophobic residue eliminated the DTT effect but with two hydrophobic residues made the pentapeptide a poor inhibitor. Replacing the first arginine with cysteine or adding an additional cysteine at the N terminus did not improve inhibition. When assessed using mouse brain lysates, the tetrapeptides also inhibited BoNT/A cleavage of the endogenous SNAP-25. The peptides penetrated the neuronal cell lines, N2A and BE(2)-M17, without adversely affecting metabolic functions as measured by ATP production and P-38 phosphorylation. Biological activity of the peptides persisted within cultured chick motor neurons and rat and mouse cerebellar neurons for more than 40 h and inhibited BoNT/A protease action inside the neurons in a dose- and time-dependent fashion. Our results define a tetrapeptide as the smallest peptide inhibitor in the backdrop of a large substrate protein of 200+ amino acids having multiple interaction regions with its cognate enzyme. The inhibitors should also be valuable candidates for drug development.     

道路边坡绿化防护工程中的生态学原理

随着我国公路和铁路建设的快速发展,公路护坡及山体边坡的绿化工程也日益受到人们的重视并付诸实施。然而,出于急功近利的目的,一些工程并没有按照科学的规律开展工作,结果导致了最终的失败。本文从生态学的观点出发,提出在路坡边坡绿化工程中应遵循的一些生态学原理,如适应性原理、生物多样性原理、生态位原理、生物共生原理、限制因子原理和力能学原理,试图为有关从业人员提供有益的帮助。     

Velocity-specific training in elbow flexors

The purpose of this study was to show that velocity-specific training may be implicated in modifications in the level of coactivation of agonist and antagonist muscles. Healthy males (n = 20) were randomly placed in to two groups: one group trained using concentric contractions (n = 12), the other was an untrained control group (n = 8). The training group underwent unilateral resistance training at a level of 35 (5)% of a one-repetition maximal contraction of the elbow flexors, executed at maximal angular velocity. Training sessions consisted of six sets of eight consecutive elbow flexions, three times per weak for a total of seven weeks. The velocity of the ballistic movements executed during training were measured using an optoelectronic measuring device (Elite), both at the beginning and at the end of the training period. Subjects were tested pre- and post-training during isokinetic maximal elbow flexions with constant angular torque (CAT) at 90 degrees (0 degrees = full extension), and at different velocities (60, 120, 180, 240 and 300 degrees x s(-1)) for concentric actions, and -60 and -30 degrees x s(-1) for eccentric and isometric contractions at 90 degrees. In order to verify the levels of activation of the agonist biceps brachii (BB) muscles and antagonist triceps brachii (TB) muscles during maximal voluntary activation, their myoelectrical activities were recorded and quantified as root mean square (RMS) amplitudes, between angles of 75 and 105 degrees . The results show that mean angular velocities between elbow angles of 75 and 105 degrees were similar before [302 (32) degrees x s(-1)] and after [312 (27) degrees x s(-1)] the training period. CAT significantly increased measures at angular velocities of 240 and 300 degrees x s(-1) by 18.7% and 23.5%, respectively. The RMS activity of BB agonist muscles was not significantly modified by training. Post-training normalized RMS amplitudes of TB antagonist muscles were inferior to those observed at pre-training, but values were only significantly different at 300 x s(-1). In conclusion, in this study we attempted to show that an increase of CAT to 240 and 300 degrees x s(-1), though velocity-specific training, may be due, in part, to a lowering of the level of coactivation.     

用于聚合酶链式反应(PCR)引物设计的计算机程序

 本文报道了两个用于PCR引物设计的计算机程序PCRDESN和PCRDESNA。PCRDESN程序主要从以下4个方面评价用户自己设计的一对引物的质量:(1)引物内的碱基反向重复或发夹结构,(2)两个引物之间的碱基互补配对,(3)两个引物之间的同源性,(4)引物的碱基组成及特点和T_m值计算。通过用多例文献发表的及本院有关实验室提供的引物对序列的验证,确定了程序的运算参数,证明该程序能较好地检验引物对的质量和解释某些PCR实验失败的原因。PCRDESNA程序采用逐级优化的方法和比PCRDESN所选用的更严紧的引物选择参数对用户提供的核酸序列进行快速检索,以确定所有可能的和合适的引物对。     

Engineering the Pattern of Protein Glycosylation Modulates the Thermostability of a GH11 Xylanase

Protein glycosylation is a common post-translational modification, the effect of which on protein conformational and stability is incompletely understood. Here we have investigated the effects of glycosylation on the thermostability of Bacillus subtilis xylanase A (XynA) expressed in Pichia pastoris. Intact mass analysis of the heterologous wild-type XynA revealed two, three, or four Hex_8–16GlcNAc₂ modifications involving asparagine residues at positions 20, 25, 141, and 181. Molecular dynamics (MD) simulations of the XynA modified with various combinations of branched Hex₉GlcNAc₂ at these positions indicated a significant contribution from protein-glycan interactions to the overall energy of the glycoproteins. The effect of glycan content and glycosylation position on protein stability was evaluated by combinatorial mutagenesis of all six potential N-glycosylation sites. The majority of glycosylated enzymes expressed in P. pastoris presented increased thermostability in comparison with their unglycosylated counterparts expressed in Escherichia coli. Steric effects of multiple glycosylation events were apparent, and glycosylation position rather than the number of glycosylation events determined increases in thermostability. The MD simulations also indicated that clustered glycan chains tended to favor less stabilizing glycan-glycan interactions, whereas more dispersed glycosylation patterns favored stabilizing protein-glycan interactions.