Resilience and restoration of tropical and subtropical grasslands,savannas, and grassy woodlands

Despite growing recognition of the conservation values of grassy biomes, our understanding of how to maintain and restore biodiverse tropical grasslands (including savannas and open‐canopy grassy woodlands) remains limited. To incorporate grasslands into large‐scale restoration efforts, we synthesised existing ecological knowledge of tropical grassland resilience and approaches to plant community restoration. Tropical grassland plant communities are resilient to, and often dependent on, the endogenous disturbances with which they evolved – frequent fires and native megafaunal herbivory. In stark contrast, tropical grasslands are extremely vulnerable to human‐caused exogenous disturbances, particularly those that alter soils and destroy belowground biomass (e.g. tillage agriculture, surface mining); tropical grassland restoration after severe soil disturbances is expensive and rarely achieves management targets. Where grasslands have been degraded by altered disturbance regimes (e.g. fire exclusion), exotic plant invasions, or afforestation, restoration efforts can recreate vegetation structure (i.e. historical tree density and herbaceous ground cover), but species‐diverse plant communities, including endemic species, are slow to recover. Complicating plant‐community restoration efforts, many tropical grassland species, particularly those that invest in underground storage organs, are difficult to propagate and re‐establish. To guide restoration decisions, we draw on the old‐growth grassland concept, the novel ecosystem concept, and theory regarding tree cover along resource gradients in savannas to propose a conceptual framework that classifies tropical grasslands into three broad ecosystem states. These states are: (1) old‐growth grasslands (i.e. ancient, biodiverse grassy ecosystems), where management should focus on the maintenance of disturbance regimes; (2) hybrid grasslands, where restoration should emphasise a return towards the old‐growth state; and (3) novel ecosystems, where the magnitude of environmental change (i.e. a shift to an alternative ecosystem state) or the socioecological context preclude a return to historical conditions.     

应用稳定性同位素技术（δ13C、δ15N）研究长江中游干流主要鱼类的营养级

应用稳定性同位素技术（δ13C、δ15N）对2011年3月至2013年12月采自长江中游干流宜昌、荆州、石首、监利、城陵矶、鄂州、九江和湖口江段的44种鱼类及3种水生无脊椎动物进行了营养级研究。长江中游干流鱼类的δ13C值范围﹣33.83‰（鳙Aristichthys nobilis） ~ ﹣17.36‰（南方鲇Silurus meridionalis）,δ15N值范围4.83‰（泥鳅Misgurnus anguillicaudatus）~ 15.13‰（翘嘴鲌Culter alburnus）。以梨形环棱螺（Bellamya purificata）的δ15N均值5.48‰作为营养级基准线（营养级 = 2）,计算出该江段水生动物的营养级处于2.42 ~ 4.88,主要集中在2.83 ~ 3.61之间,鱼类平均营养级为3.28。营养级大于2.83的鱼类种类数量占了总生物种数的80.85%。大刺鳅（Mastacembelus armatus）和长春鳊（Parabramis pekinensis）营养级最低,分别为2.42 ± 0.49和2.56 ± 0.52,营养层级大于4.0的高级消费者为太湖新银鱼（Neosalanx taihuensis）、短颌鲚（Coilia brachygnathus）、鳙和长蛇鮈（Saurogobio dumerili）,分别为4.88 ± 0.01、4.37 ± 0.27、4.32 ± 0.35和4.09 ± 0.78,小黄黝鱼（Micropercops swinhonis)、鱤（Elopichthys bambusa）、鱖（Siniperca chuatsi）、翘嘴鲌、青鱼（Mylopharyngodon piceus）和南方鲇的营养级分别3.99、3.92 ± 0.16、3.89 ± 0.27、3.87 ± 0.62、3.59 ± 0.69和3.59 ± 0.57。本研究旨为长江中游渔业资源评估及其合理利用提供基础科学资料,为进一步研究长江中游干流渔业资源营养结构的动态变化及受人为活动干扰影响等提供科学参考依据。     

The N17 domain mitigates nuclear toxicity in a novel zebrafish Huntington’s disease model

Background

Although the genetic cause for Huntington’s disease (HD) has been known for over 20 years, the mechanisms that cause the neurotoxicity and behavioral symptoms of this disease are not well understood. One hypothesis is that N-terminal fragments of the HTT protein are the causative agents in HD and that peptide sequences adjacent to the poly-glutamine (Q) repeats modify its toxicity. Here we test the function of the N-terminal 17 amino acids (N17) in the context of the exon 1 fragment of HTT in a novel, inducible zebrafish model of HD.

Results

Deletion of N17 coupled with 97Q expansion (mHTT-ΔN17-exon1) resulted in a robust, rapidly progressing movement deficit, while fish with intact N17 and 97Q expansion (mHTT-exon1) have more delayed-onset movement deficits with slower progression. The level of mHTT-ΔN17-exon1 protein was significantly higher than mHTT-exon1, although the mRNA level of each transgene was marginally different, suggesting that N17 may regulate HTT protein stability in vivo. In addition, cell lineage specific induction of the mHTT-ΔN17-exon1 transgene in neurons was sufficient to recapitulate the consequences of ubiquitous transgene expression. Within neurons, accelerated nuclear accumulation of the toxic HTT fragment was observed in mHTT-ΔN17-exon1 fish, demonstrating that N17 also plays an important role in sub-cellular localization in vivo.

Conclusions

We have developed a novel, inducible zebrafish model of HD. These animals exhibit a progressive movement deficit reminiscent of that seen in other animal models and human patients. Deletion of the N17 terminal amino acids of the huntingtin fragment results in an accelerated HD-like phenotype that may be due to enhanced protein stability and nuclear accumulation of HTT. These transgenic lines will provide a valuable new tool to study mechanisms of HD at the behavioral, cellular, and molecular levels. Future experiments will be focused on identifying genetic modifiers, mechanisms and therapeutics that alleviate polyQ aggregation in the nucleus of neurons.

     

Antibody Engineering & Therapeutics 2015: The Antibody Society's annual meeting December 7–10, 2015, San Diego,CA

Antibody Engineering & Therapeutics, the annual meeting of The Antibody Society, will be held in San Diego, CA in early December 2015. In this meeting preview, the chairs provide their thoughts on the importance of their session topics, which include antibody effector functions, reproducibility of research and diagnostic antibodies, new developments in antibody-drug conjugates (ADCs), preclinical and clinical ADC data, new technologies and applications for bispecific antibodies, antibody therapeutics for non-cancer and orphan indications, antibodies to harness the cellular immune system, overcoming resistance to clinical immunotherapy, and building comprehensive IGVH-gene repertoires through discovering, confirming and cataloging new germline IGVH genes. The Antibody Society''s special session will focus on “Antibodies to watch” in 2016, which are a subset of the nearly 50 antibodies currently in Phase 3 clinical studies. Featuring over 100 speakers in total, the meeting will commence with keynote presentations by Erica Ollmann Saphire (The Scripps Research Institute), Wayne A. Marasco (Dana-Farber Cancer Institute/Harvard Medical School), Joe W. Gray (Oregon Health & Science University), and Anna M. Wu (University of California Los Angeles), and it will conclude with workshops on the promise and challenges of using next-generation sequencing for antibody discovery and engineering from synthetic and in vivo libraries and on computational antibody design.     

Fibroblast growth factor family aberrations in cancers: clinical and molecular characteristics

Fibroblast growth factor ligands and receptors (FGF and FGFR) play critical roles in tumorigenesis, and several drugs have been developed to target them. We report the biologic correlates of FGF/FGFR abnormalities in diverse malignancies. The medical records of patients with cancers that underwent targeted next generation sequencing (182 or 236 cancer-related genes) were reviewed. The following FGF/FGFR genes were tested: FGF3, 4, 6, 7, 10, 12, 14, 19, 23 and FGFR1, 2, 3, and 4. Of 391 patients, 56 (14.3%) had aberrant FGF (N = 38, all amplifications) and/or FGFR (N = 22 including 5 mutations and one FGFR3-TACC3 fusion). FGF/FGFR aberrations were most frequent in breast cancers (26/81, 32.1%, p = 0.0003). In multivariate analysis, FGF/FGFR abnormalities were independently associated with CCND1/2, RICTOR, ZNF703, RPTOR, AKT2, and CDK8 alterations (all P < 0.02), as well as with an increased median number of alterations (P < 0.0001). FGF3, FGF4, FGF19 and CCND1 were co-amplified in 22 of 391 patients (5.6%, P < 0.0001), most likely because they co-localize on the same chromosomal region (11q13). There was no significant difference in time to metastasis or overall survival when comparing patients harboring FGF/FGFR alterations versus those not. Overall, FGF/FGFR was one of the most frequently aberrant pathways in our population comprising patients with diverse malignancies. These aberrations frequently co-exist with anomalies in a variety of other genes, suggesting that tailored combination therapy may be necessary in these patients.     

氦氧饱和高气压暴露对铜绿假单胞菌毒力表型的诱导调节

研究氦氧饱和高气压暴露对铜绿假单胞菌与急性侵袭感染相关的主要毒力因子表型的影响。分别检测暴露前后铜绿假单胞菌的生长速度、运动能力,对乙酰胺的分解能力和培养细胞外液中绿脓菌素、弹性蛋白酶的分泌水平和活性。在动物水平验证毒力的变化。结果显示,经4.5 MPa氦氧饱和加压暴露后,与对照组相比铜绿假单胞菌的生长增殖、运动能力和对乙酰胺的分解能力增强,绿脓菌素分泌增加,弹性蛋白酶活性增强;暴露后细菌对实验小鼠的毒性增加。因此氦氧饱和高气压环境对铜绿假单胞菌的毒力表型有正调控作用。     

Evaluation of zona pellucida birefringence intensity during in vitro maturation of oocytes from stimulated cycles

Background  

This study evaluated whether there is a relationship between the zona pellucida birefringence (ZP-BF) intensity and the nuclear (NM) and cytoplasmic (CM) in vitro maturation of human oocytes from stimulated cycles.     

甲亢甲低患者肝纤维化指标检测的临床意义分析

目的：探讨甲状腺功能亢进（甲亢）、甲状腺功能减低（甲低）与肝纤维化指标的关系及其可能的机制。方法：采用放射免疫分析法（R1A）检测57例甲亢患者、43例甲低患者、39例甲亢治疗后甲状腺激素正常者和50例健康成人的血清Ⅳ型胶原（1V-C）、Ⅲ型前胶原（PCⅢ）、透明质酸（HA）、层粘连蛋白（LN）、T3、T4、FT3、FT4、TSH、TGA、TMA含量。结果：甲亢患者组血清中1V-C、PCⅢ含量比正常对照组及甲低患者组显著性增高（P〈0.05）;治疗后甲状腺激素下降,1V-C、PCⅢ含量也随之下降（与治疗前比较P〈0.01）;HA、LN在四组中无显著性差异（P〉0.05）,在甲亢治疗前后无显著性差异（P〉0.05）。各项肝纤维化指标与TGA、TMA的阳性率无关。结论：甲亢患者可有不同程度的肝功能损害,血清中甲状腺激素水平增高时,1V-C、PCⅢ水平也增高,在用1V-C、PCⅢ判断肝纤维化时应注意有无甲状腺疾病特别是甲亢。未发现HA、LN含量与甲状腺激素水平的关系。     

Genetic diversity and differentiation in natural and reintroduced populations of Bencomia exstipulata and comparisons with B. caudata (Rosaceae) in the Canary Islands: an analysis using microsatellites

Variation at five polymorphic microsatellite loci was used to investigate genetic diversity and differentiation of two tetraploid Canarian endemics, Bencomia exstipulata and B. caudata. Data were analysed and are discussed in terms of tetrasomic (autotetraploid) and disomic (allotetraploid) inheritance. In both cases, genetic diversity values were similar to those described in other tetraploid plant species. High genetic differentiation between the only two described natural populations of B. exstipulata was detected (F_ST = 0.411). Bayesian cluster analysis revealed a geographical structure with distinct genetic groups from each island. High genetic differentiation and low genetic diversity of the B. exstipulata population from Tenerife suggest a recent population bottleneck, perhaps caused by the most recent major volcanic eruption, for this natural locality. This may be heightened by possible inbreeding depression and the monoecy of these species. Polymorphic microsatellite loci were also tested across all species in the Bencomia alliance. These reliably amplified the target sequence, suggesting a high degree of conservation of the sequences flanking the microsatellites. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160 , 429–441.     

Further evidence of the African antiquity of hyaenodontid (‘Creodonta’, Mammalia) evolution

We report here the new ‘creodont’ Lahimia selloumi gen. et sp. nov. from the late Palaeocene of the Ouled Abdoun Basin (Morocco) as the oldest known Hyaenodontidae with Tinerhodon from the Ouarzazate Basin (Morocco). By contrast to Tinerhodon, Lahimia is unexpectedly derived. Most of its specializations, such as the shortening of the anterior dentition (e.g. loss of P₁) and the talonid reduction and simplification, are strikingly shared with Boualitomus from the Ypresian of the Ouled Abdoun Basin, and are distinctive from other hyaenodontids, including ‘proviverrines’. They are interpreted as synapomorphies evidencing a precociously specialized early African hyaenodontid lineage. Although Lahimia and Boualitomus remain known only by the lower dentition, their relationships with Koholia are suggested by comparison of their molar occlusal pattern. Lahimia and Boualitomus are referred to the Koholiinae, which is representative of an old African endemic lineage, as initially recognized. This remarkable lineage is characterized by synapomorphies of Lahimia and Boualitomus, and also by a shared original prevallum/postvallid shearing. The discovery of Lahimia provides direct evidence for the antiquity of the African evolution of the Hyaenodontidae. This is in agreement with an African origin of the Hyaenodontidae, and with the probable diphyletism of the ‘Creodonta’. Lahimia and the Koholiinae, as well as the diversity of the first Laurasian hyaenodontid lineages, emphasize our poor knowledge of the striking early African hyaenodontid radiation.