The use of modelling and simulation approach in reconstructing past landscapes from fossil pollen data: a review and results from the POLLANDCAL network

Information on past land cover in terms of absolute areas of different landscape units (forest, open land, pasture land, cultivated land, etc.) at local to regional scales is needed to test hypotheses and answer questions related to climate change (e.g. feedbacks effects of land-cover change), archaeological research, and nature conservancy (e.g. management strategy). The palaeoecological technique best suited to achieve quantitative reconstruction of past vegetation is pollen analysis. A simulation approach developed by Sugita (the computer model POLLSCAPE) which uses models based on the theory of pollen analysis is presented together with examples of application. POLLSCAPE has been adopted as the central tool for POLLANDCAL (POLlen/LANdscape CALibration), an international research network focusing on this topic. The theory behind models of the pollen–vegetation relationship and POLLSCAPE is reviewed. The two model outputs which receive greatest attention in this paper are the relevant source area of pollen (RSAP) and pollen loading in mires and lakes. Six examples of application of POLLSCAPE are presented, each of which explores a possible use of the POLLANDCAL tools and a means of validating or evaluating the models with empirical data. The landscape and vegetation factors influencing the size of the RSAP, the importance of pollen productivity estimates (PPEs) for the model outputs, the detection of small and rare patches of plant taxa in pollen records, and quantitative reconstructions of past vegetation and landscapes are discussed on the basis of these examples. The simulation approach is seen to be useful both for exploring different vegetation/landscape scenarios and for refuting hypotheses.     

退耕区域生态系统服务作用关系尺度效应及分异机制——以安塞区为例

生态系统服务的形成依赖于一定时空尺度上的生态过程。因此,探究生态系统服务在不同空间尺度的特征、关联和效应对于丰富生态系统服务的可持续管理具有重要的理论价值和实践意义。以典型退耕县域安塞区作为研究对象,基于生态模型定量评估了6项重要的生态系统服务,采用相关系数法、双变量空间自相关以及地理探测器揭示了不同空间尺度上生态系统服务作用关系的尺度效应及分异机制。研究结果显示：(1)退耕区域内,生态系统服务之间以协同关系为主,其中调节服务与支持服务的协同关系最强(|r|≥0.5),而权衡关系发生在文化服务与其他服务之间。从时间序列来看,调节服务与支持服务的作用关系较为稳定,在研究期间保持为协同关系,且协同度在退耕还林后有所提升;(2)生态系统服务作用关系的空间尺度效应主要表现在作用关系的方向变化与空间显著性的差异。在网格尺度中,生态系统服务之间的关系较为稳健,作用方向的变化主要发生在网格尺度与行政单元之间,且随研究尺度的加大,服务之间作用关系的空间显著性降低;(3)生态系统服务的权衡与协同是自然因子和社会因子共同作用的结果。退耕区人类活动干扰较小,自然因子的解释力(q均值0.1507)高于社会因子...     

The General Dispute Settlement System of the UN Convention on the Law of the Sea: Overview,Context, and Use

This article provides an introduction to the contributions in this special issue of Ocean Development & International Law. It offers an overview of the dispute settlement provisions of the UN Convention on the Law of the Sea, placing them in the context of dispute settlement in international law generally, and explaining the extent to which they have been used so far.     

The phylogeny of Ephemeroptera in Pterygota revealed by the mitochondrial genome of Siphluriscus chinensis (Hexapoda: Insecta)

The mayfly species Siphluriscus chinensis (Siphluriscidae) has valuable structures useful for phylogeny reconstruction, given its putative basal position within the Ephemeroptera. Here its nearly complete mitochondrial genome is sequenced. We built phylogenetic trees through multiple analytical strategies with some other insect mitogenomes. Structurally, the obtained mitochondrial genome of S. chinensis is 16,616 bp in length, ¹ containing 37 genes and an extra trnK-like (trnK2 (AAA)) gene. The 12 PCGs start with typical ATN codons, except the nad1 gene which starts with an unnormalized TTG. Like other known mayfly mitogenomes, the strand bias has negative AT-skew and negative GC-skew. Phylogenetically, our topologies suggest that Odonata is the basally diverged clade in Pterygota; Ephemeroptera is the sister group of the Neoptera; and S. chinensis is indeed the most basal mayfly branch.     

The complete mitochondrial genome of the sycamore lace bug Corythucha ciliata (Hemiptera: Tingidae)

The complete mitochondrial genome of the sycamore lace bug, Corythucha ciliata, was sequenced in this study. It represents the first sequenced mitogenome of family Tingidae in Heteroptera. The mitogenome of C. ciliata is 15,257 bp and contains 37 genes including 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes and a large non-coding region. Gene arrangement, nucleotide content, codon usage, and amino acid composition and asymmetry indicate a high degree of conservation with six other species of Cimicomorpha. The 13 PCGs initiated with ATN as the start codon and terminated with TAA, TA or T as stop codon. The evolutionary rate of each PCG was different, among which ATP8 showed the highest rate while ATP6 indicated the lowest rate. The 22 tRNAs genes apparently fold into a typical cloverleaf structure; however, the anticodon (TTC) of trnSer (AGN) differs from other Heteropteran insects. Secondary structure modeling of rRNA genes revealed similarity to other insects, except for two incomplete helices (H1648 and H2735) in lrRNA. The predicted secondary structure of lrRNA indicates 45 helices in six domains, whereas srRNA has 27 helices in three domains. Three potential stem–loops and two tandem repeats (–TCTAAT–) were identified in the A+T-rich region. Phylogenetic analysis indicated that C. ciliata is a sister group to other Heteroptera species based on analysis of the 13 PCGs.     

Human Genetics and Politics as Mutually Beneficial Resources: The Case of the Kaiser Wilhelm Institute for Anthropology, Human Heredity and Eugenics During the Third Reich

This essay analyzes one of Germany’s former premier research institutions for biomedical research, the Kaiser Wilhelm Institute for Anthropology, Human Heredity and Eugenics (KWIA) as a test case for the way in which politics and human heredity served as resources for each other during the Third Reich. Examining the KWIA from this perspective brings us a step closer to answering the questions at the heart of most recent scholarship concerning the biomedical community under the swastika: (1) How do we explain why the vast majority of German human geneticists and eugenicists were willing to work for the National Socialist state and, at the very least, legitimized its exterminationist racial policy; and (2) what accounts for at least some of Germany’s most renowned medically trained professionals’ involvement in forms of morally compromised science that wholly transcend the bounds of normal scientific practice? Although a complete answer to this question must await an examination of other German biological research centers, the present study suggests that during the Nazi period the symbiotic relationship between human genetics and politics served to radicalize both. The dynamic between the science of human heredity and Nazi politics changed the research practice of some of the biomedical sciences housed at the KWIA. It also simultaneously made it easier for the Nazi state to carry out its barbaric racial program leading, finally, to the extermination of millions of so-called racial undesirables.     

The effect of pH on the formal reduction potential of adrenodoxin in the presence and absence of adrenodoxin reductase: the implication in the electron transfer mechanism

We have investigated the formal reduction potentials (E degrees') of adrenodoxin with and without adrenodoxin reductase in order to elucidate the mechanism of electron transfer from adrenodoxin reductase (a flavoprotein) to adrenodoxin (an iron-sulfur protein). It was found by our spectropotentiostatic method that adrenodoxin showed no variation of E degrees' at different pH's in the absence of adrenodoxin reductase. The average E degrees' was -252 +/- 2 mV in the pH range between 6.0 and 8.3. In the presence of adrenodoxin reductase, adrenodoxin exhibited, on the other hand, a pH dependence of E degrees' at pH higher than 7.2 with a slope of -59 mV per pH unit: Adrenodoxin molecule possesses one protonation site with a pKa of 7.2. Cyclic voltammograms of adrenodoxin additionally revealed that the reoxidation reaction of reduced adrenodoxin is very slow in the absence of adrenodoxin reductase, but that it is readily reoxidized in the presence of adrenodoxin reductase.     

The complete mitochondrial genome of Pauropus longiramus (Myriapoda: Pauropoda): implications on early diversification of the myriapods revealed from comparative analysis

Myriapods are among the earliest arthropods and may have evolved to become part of the terrestrial biota more than 400 million years ago. A noticeable lack of mitochondrial genome data from Pauropoda hampers phylogenetic and evolutionary studies within the subphylum Myriapoda. We sequenced the first complete mitochondrial genome of a microscopic pauropod, Pauropus longiramus (Arthropoda: Myriapoda), and conducted comprehensive mitogenomic analyses across the Myriapoda. The pauropod mitochondrial genome is a circular molecule of 14,487 bp long and contains the entire set of thirty-seven genes. Frequent intergenic overlaps occurred between adjacent tRNAs, and between tRNA and protein-coding genes. This is the first example of a mitochondrial genome with multiple intergenic overlaps and reveals a strategy for arthropods to effectively compact the mitochondrial genome by overlapping and truncating tRNA genes with neighbor genes, instead of only truncating tRNAs. Phylogenetic analyses based on protein-coding genes provide strong evidence that the sister group of Pauropoda is Symphyla. Additionally, approximately unbiased (AU) tests strongly support the Progoneata and confirm the basal position of Chilopoda in Myriapoda. This study provides an estimation of myriapod origins around 555 Ma (95% CI: 444-704 Ma) and this date is comparable with that of the Cambrian explosion and candidate myriapod-like fossils. A new time-scale suggests that deep radiations during early myriapod diversification occurred at least three times, not once as previously proposed. A Carboniferous origin of pauropods is congruent with the idea that these taxa are derived, rather than basal, progoneatans.     

The anti-cancer drug chlorambucil as a substrate for the human polymorphic enzyme glutathione transferase P1-1: kinetic properties and crystallographic characterisation of allelic variants

The commonly used anti-cancer drug chlorambucil is the primary treatment for patients with chronic lymphocytic leukaemia. Chlorambucil has been shown to be detoxified by human glutathione transferase Pi (GST P1-1), an enzyme that is often found over-expressed in cancer tissues. The allelic variants of GST P1-1 are associated with differing susceptibilities to leukaemia and differ markedly in their efficiency in catalysing glutathione (GSH) conjugation reactions. Here, we perform detailed kinetic studies of the allelic variants with the aid of three representative co-substrates. We show that the differing catalytic properties of the variants are highly substrate-dependent. We show also that all variants exhibit the same temperature stability in the range 10 °C to 45 °C. We have determined the crystal structures of GST P1-1 in complex with chlorambucil and its GSH conjugate for two of these allelic variants that have different residues at positions 104 and 113. Chlorambucil is found to bind in a non-productive mode to the substrate-binding site (H-site) in the absence of GSH. This result suggests that under certain stress conditions where GSH levels are low, GST P1-1 can inactivate the drug by sequestering it from the surrounding medium. However, in the presence of GSH, chlorambucil binds in the H-site in a productive mode and undergoes a conjugation reaction with GSH present in the crystal. The crystal structure of the GSH-chlorambucil complex bound to the *C variant is identical with the *A variant ruling out the hypothesis that primary structure differences between the variants cause structural changes at the active site. Finally, we show that chlorambucil is a very poor inhibitor of the enzyme in contrast to ethacrynic acid, which binds to the enzyme in a similar fashion but can act as both substrate and inhibitor.     

A cytokine super cyclone in COVID-19 patients with risk factors: the therapeutic potential of BCG immunization

The seventh human coronavirus SARS-CoV2 belongs to the cluster of extremely pathogenic coronaviruses including SARS-CoV and MERS-CoV, which can cause fatal lower respiratory tract infection. Likewise, SARS-CoV2 infection can be fatal as the disease advances to pneumonia, followed by acute respiratory distress syndrome (ARDS). The development of lethal clinical symptons is associated with an exaggerated production of inflammatory cytokines, referred to as the cytokine storm, is a consequence of a hyperactivated immune response aginst the infection. In this article, we discuss the pathogenic consequences of the cytokine storm and its relationship with COVID-19 associated risk factors. The increased pro-inflammatory immune status in patients with risk factors (diabetes, hypertension, cardiovascular disease, COPD) exacerbates the Cytokine-storm of COVID-19 into a ‘Cytokine Super Cyclone’. We also evaluate the antiviral immune responses provided by BCG vaccination and the potential role of ‘trained immunity’ in early protection against SARS-CoV2.