From the Cover: Amazonian functional diversity from forest canopy chemical assembly

Patterns of tropical forest functional diversity express processes of ecological assembly at multiple geographic scales and aid in predicting ecological responses to environmental change. Tree canopy chemistry underpins forest functional diversity, but the interactive role of phylogeny and environment in determining the chemical traits of tropical trees is poorly known. Collecting and analyzing foliage in 2,420 canopy tree species across 19 forests in the western Amazon, we discovered (i) systematic, community-scale shifts in average canopy chemical traits along gradients of elevation and soil fertility; (ii) strong phylogenetic partitioning of structural and defense chemicals within communities independent of variation in environmental conditions; and (iii) strong environmental control on foliar phosphorus and calcium, the two rock-derived elements limiting CO₂ uptake in tropical forests. These findings indicate that the chemical diversity of western Amazonian forests occurs in a regionally nested mosaic driven by long-term chemical trait adjustment of communities to large-scale environmental filters, particularly soils and climate, and is supported by phylogenetic divergence of traits essential to foliar survival under varying environmental conditions. Geographically nested patterns of forest canopy chemical traits will play a role in determining the response and functional rearrangement of western Amazonian ecosystems to changing land use and climate.Foliage is a locus of chemical investment undertaken by plants to capture and use sunlight for carbon gain under changing environmental conditions and compete with coexisting individuals and species. Plants acquire essential chemical elements from soils, and they synthesize a wide variety of compounds in their leaves to support multiple interdependent physiological processes. Uptake of nitrogen and phosphorus plus the internal production of photosynthetic pigments, including chlorophyll and carotenoids, are required for light capture and carbon fixation in foliage (1). Soluble carbon, primarily comprised of sugars, starch, pectins, and lipids, is then synthesized to meet the energy requirements of the entire plant (2). Other macro- and micronutrients (e.g., calcium) underpin critical leaf functions, such as stomatal conductance and cell wall development. To support the carbon capture process, foliar structural compounds, such as lignin and cellulose, are synthesized to provide strength and longevity (3), and polyphenols are generated for chemical defense (4). Variation in this leaf chemical portfolio expresses multiple strategies evolved in plants to maximize fitness through growth and longevity in any given environment.Despite our understanding of plant chemical and physiological processes, the way that environment and evolution interact to determine geographic variation in plant canopy chemistry remains a mystery. In turn, this shortfall sets a fundamental limit on our knowledge of the core determinants of functional diversity in and across ecosystems, with cascading limits on our understanding of biogeographic and biogeochemical processes. Although much research has either focused on plant functional trait differentiation among coexisting species in communities (5) or emphasized trait convergence in response to environmental filters, such as climate and soils (6), few studies have examined the interconnections between phylogeny and environment in determining functional diversity by way of canopy chemistry (7). This gap is particularly true in the tropics, where our understanding of the interplay between evolution and environmental factors is perhaps weakest because of high plant diversity and a poor understanding of plant community assembly (8). Today, we know very little about canopy chemical traits at community to biome scales in the tropics (9).Western Amazonian forests are a case in point. The forested corridor stretching from Colombia to Bolivia and from the Andean tree line to the Amazon lowlands harbors thousands of plant species arranged in communities distributed across widely varying elevation, geologic, soil, and hydrologic conditions (10, 11). Although the general biological diversity of the region is coming into focus (12, 13), the functional diversity of the forest remains unknown. To understand the regional assembly of forest functional traits and their underlying controls in Amazonia, we must determine the degree to which canopy chemistry is environmentally filtered and phylogenetically partitioned as well as how chemical traits are organized within and among communities. If chemical traits are plastic among coexisting taxa, then biological diversity may be decoupled from functional diversity. Alternatively, if there exists strong phylogenetic organization of canopy chemical traits, then biological diversity may express functional trait diversity and vice versa. Determining the connection between functional and biological diversity may help to explain how so many species coexist within communities and how communities differ throughout the region (14).Here, we are interested in chemical diversity among coexisting tropical canopy tree species and their evolved responses to regional environmental filters thought to limit functional trait divergence. Thus, we developed chemical trait portfolios for tree canopies spread along a 3,500-m elevation gradient stretching from lowland Amazonia to the Andean tree line in Peru (SI Methods and Tables S1 and S2). We assessed the role of taxonomy as well as within- (intraspecific) and between-species (interspecific) variations in determining community and regional chemical assembly. Our study incorporated 2,420 canopy tree species in 19 forests along the elevation gradient, and our sampling included the majority of canopy tree species known to occur in the western Amazon (11, 12). Because submontane to montane Andean forests exist primarily on younger geologic surfaces, whereas lowland forests occur on a mosaic of young to old substrates, we also considered the role of soils in mediating canopy chemical trait distributions. We asked two questions. (i) How does the canopy chemistry of western Amazonian forests vary with elevation? (ii) How much of the variation is explained by taxonomy compared with plasticity within taxa? We focused on light capture and growth traits (including N, P, and photosynthetic pigments) as well as structure and defense traits (total C, lignin, cellulose, and phenols). We also considered Ca as a key element regulating foliar metabolism and nutrient cycling in humid tropical ecosystems (15, 16), and we measured δ¹³C and soluble carbon as indicators of performance (17). Finally, we assessed sources of variation in leaf mass per area (LMA), a foliar structural property expressing plant investment strategies based on multiple chemical and physiological traits (18).     

Increasing homogeneity in global food supplies and the implications for food security

The narrowing of diversity in crop species contributing to the world’s food supplies has been considered a potential threat to food security. However, changes in this diversity have not been quantified globally. We assess trends over the past 50 y in the richness, abundance, and composition of crop species in national food supplies worldwide. Over this period, national per capita food supplies expanded in total quantities of food calories, protein, fat, and weight, with increased proportions of those quantities sourcing from energy-dense foods. At the same time the number of measured crop commodities contributing to national food supplies increased, the relative contribution of these commodities within these supplies became more even, and the dominance of the most significant commodities decreased. As a consequence, national food supplies worldwide became more similar in composition, correlated particularly with an increased supply of a number of globally important cereal and oil crops, and a decline of other cereal, oil, and starchy root species. The increase in homogeneity worldwide portends the establishment of a global standard food supply, which is relatively species-rich in regard to measured crops at the national level, but species-poor globally. These changes in food supplies heighten interdependence among countries in regard to availability and access to these food sources and the genetic resources supporting their production, and give further urgency to nutrition development priorities aimed at bolstering food security.A shared axiom of ecology and nutrition is that, within certain ranges, diversity enhances the health and function of complex biological systems. Species diversity has been shown to stimulate productivity, stability, ecosystem services, and resilience in natural (1–5) and in agricultural ecosystems (6–13). Likewise, variation in food species contributing to diet has been associated with nutritional adequacy (14–17) and food security (18).The development of sedentary agricultural societies and further rise of modern agriculture is generally considered to have led to a decline in the total number of plant species upon which humans depend for food (19, 20), particularly the wild, semidomesticated, and cultivated vegetables and fruits, spices, and other food plants that supplemented staple crops with the provision of micronutrients and that bolstered food security historically during crop failures (21). Harlan (20) warned that

most of the food for mankind comes from a small number of crops and the total number is decreasing steadily. In the United States in the past 40 years, many vegetables and fruits have disappeared from the diet, and the trend is going on all over the world. More and more people will be fed by fewer and fewer crops.

More recent analyses of dietary transition in developing countries in association with globalization have noted increases in the diversity of plants contributing to diets locally, along with a Westernization transition in preference of energy-dense foods (i.e., animal products, plant oils, and sugars) over cereals, pulses, and vegetables, and of particular major crop plants within these food categories over traditional crops (22, 23). The impact of such changes on overall crop diversity worldwide has not been comprehensively documented, although recent changes in varietal and allelic level diversity of some crops have been investigated (24–26). Given the potential food security implications of narrowing of the diversity of crop species both in production systems and in food supplies, an assessment of the global state of crop plant species diversity is warranted.Here we examine changes in the diversity of the portfolio of crop species upon which humans primarily depend for food security in regard to calories, protein, fat, and food weight. Using national per capita food supply data published by the Food and Agriculture Organization (FAO) of the United Nations, we analyzed trends in the richness, abundance, and composition of measured crop commodities in the food supplies of 152 countries comprising 98% of the world’s population from 1961 to 2009.     

Diversity of and initiatives for hypertension management in Asia—Why we need the HOPE Asia Network

The Hypertension Cardiovascular Outcome Prevention and Evidence in Asia (HOPE Asia) Network was set up to improve the management of hypertension in Asia with the ultimate goal of achieving “zero” cardiovascular events. Asia is a diverse continent, and the prevalence of hypertension has increased over the last 30 years. There are a number of Asia‐specific features of hypertension and hypertension‐related cardiovascular complications, which means that a region‐specific approach is needed. White‐coat hypertension will become more of an issue over time as Asian populations age, and masked hypertension is more prevalent in Asian than in Western countries. Identifying and treating masked hypertension is important to reduce cardiovascular risk. Abnormal patterns of blood pressure (BP) variability common in Asia include exaggerated early morning BP surge and nocturnal hypertension. These are also important cardiovascular risk factors that need to be managed. Home blood pressure monitoring (HBPM) is an important tool for detecting white‐coat and masked hypertension, and monitoring BP variability, and practices in Asia are variable. Use of HBPM is important given the Asia‐specific features of hypertension, and strategies are needed to improve and standardize HBPM usage. Development of HBPM devices capable of measuring nocturnal BP along with other information and communication technology‐based strategies are key developments in the widespread implementation of anticipation medicine strategies to detect and prevent cardiovascular events in patients with hypertension. Region‐wide differences in hypertension prevalence, control, and management practices in Asia highlight the importance of information sharing to facilitate best practices.     

疫苗候选抗原Pvs48/45在中缅边境的遗传多样性特点

目的 了解间日疟原虫传播阻断疫苗候选抗原Pvs48/45在中缅边境地区的基因多态性和自然选择特点。方法 提取39例来自中缅边境主要流行区(Laiza)的间日疟原虫基因组DNA,采用巢式PCR(nest-PCR)扩增Pvs48/45基因开放阅读区(Open reading frame, ORF);通过MEGA 4.0、DnaSP v5.10和NETWORK 4.6对Pvs48/45基因多态性和自然选择特点进行分析。结果 研究发现了6个突变位点,均为非同义突变(E35K ,H211N ,K250N ,D335Y,A376T,K418R),导致了5种单倍型;Pvs48/45基因的核苷酸多态性水平极低(π=0.00064),CRDⅢ区最高(π=0.00163);多种中性检验均表明Pvs48/45基因处于平衡选择;种群进化分析和单倍型网络图显示Pvs48/45具有较强的地理分化,且H2型为中缅边境地区频率最高的单倍型。结论 Pvs48/45在中缅边境地区遗传多样性很低,且在进化过程中经历平衡选择,提示其可作为传播阻断疫苗候选靶点;Pvs48/45在全球具有较强的地理分化,应根据地区遗传特点开发更加有效的传播阻断疫苗。     

Multiple self-splicing introns in the 16S rRNA genes of giant sulfur bacteria

The gene encoding the small subunit rRNA serves as a prominent tool for the phylogenetic analysis and classification of Bacteria and Archaea owing to its high degree of conservation and its fundamental function in living organisms. Here we show that the 16S rRNA genes of not-yet-cultivated large sulfur bacteria, among them the largest known bacterium Thiomargarita namibiensis, regularly contain numerous self-splicing introns of variable length. The 16S rRNA genes can thus be enlarged to up to 3.5 kb. Remarkably, introns have never been identified in bacterial 16S rRNA genes before, although they are the most frequently sequenced genes today. This may be caused in part by a bias during the PCR amplification step that discriminates against longer homologs, as we show experimentally. Such length heterogeneity of 16S rRNA genes has so far never been considered when constructing 16S rRNA-based clone libraries, even though an elongation of rRNA genes due to intervening sequences has been reported previously. The detection of elongated 16S rRNA genes has profound implications for common methods in molecular ecology and may cause systematic biases in several techniques. In this study, catalyzed reporter deposition-fluorescence in situ hybridization on both ribosomes and rRNA precursor molecules as well as in vitro splicing experiments were performed and confirmed self-splicing of the introns. Accordingly, the introns do not inhibit the formation of functional ribosomes.     

Antibiotic effects on bacterial profile in osteonecrosis of the jaw

Oral Diseases (2011) 18 , 85–95 Objective: Oral infection is considered to play a critical role in the pathogenesis of bisphosphonate‐related osteonecrosis of the jaw (BRONJ), and antibiotic therapy has become a mainstay of BRONJ therapy. This study was aimed to investigate the effect of antibiotics on bacterial diversity in BRONJ tissues. Materials and methods: The bacterial profile from soft tissues associated with the BRONJ lesion was determined using 16S rRNA‐based denaturing gradient gel electrophoresis (DGGE) and sequencing. Twenty BRONJ subjects classified as stage 0–2 were enrolled in this study, and patient groups were divided into an antibiotic cohort (n = 10) treated with systemic antibiotic and a non‐antibiotic cohort (n = 10) with no prior antibiotic therapy. Results: The DGGE fingerprints indicated no significant differences in bacterial diversity of BRONJ tissue samples. Patients on antibiotics had higher relative abundance of phylum Firmicutes with bacterial species, Streptococcus intermedius, Lactobacillus gasseri, Mogibacterium timidum, and Solobacterium moorei, whereas patients without antibiotics had greater amounts of Parvimonas micra and Streptococcus anginosus. Thirty percent of bacterial populations were uncultured (yet‐to be cultured) phylotypes. Conclusion: This study using limited sample size indicated that oral antibiotic therapy may have a limited efficacy on the bacterial population associated with BRONJ lesions.     

PCR-DGGE检测早期儿童龋治疗前后口腔菌群多样性的初步研究

目的:应用PCR-变性梯度凝胶电泳技术(denaturing gradient gel electrophoresis,DGGE)技术检测早期儿童龋治疗前后唾液中微生物多样性的变化。方法:选取北京大学燕东幼儿园22名3～5岁儿童进行口腔检查,在龋齿治疗前和治疗后2周分别取样,采用PCR-DGGE技术检测受试儿童唾液样本,分析治疗前后唾液微生物多样性的变化。结果:治疗前唾液样本DGGE条带数为23±2.9,治疗后唾液样本DGGE条带数为28±4.1,差异有显著性(P<0.01);在同一时期内各唾液样本DGGE图谱的相似性高于不同时期样本之间。结论:PCR-DGGE技术可用于与龋病相关细菌的生物多样性的研究以及监测微生物群落组成的动态变化。     

The contribution of sexology to contemporary sexuality education

This paper draws upon recent feminist and gay scholarship in arguing that sexuality is an inherently political realm of thinking and activity. Sexology¹ is a profession which claims special expertise in relation to sexuality and might, at first glance, be thought to have a key role to play within sexuality education, particularly in the face of the global pandemic of HIV infection. It is argued that the potential contribution of sexology is ultimately compromised by its reluctance to acknowledge the inherently political nature of its activity.     

Conducting neuropsychological assessment with transgender individuals

Abstract

Objective: The purpose of this paper is to provide an overview of helpful clinical practices when working with transgender adult individuals. Method: While the number of openly transgender individuals appears to be growing with society’s increased acceptance and awareness, many neuropsychologists have had few opportunities to gain experience with this patient population. In this article, we review the existing literature as it relates to clinical neuropsychological practice. Results: We describe important terminology, ideals for creating an environment of respect, and how existing clinical guidelines for transgender individuals may apply to neuropsychology. In addition, we review the primary steps in the assessment process and provide a set of principles and recommendations for conducting neuropsychological assessments with transgender patients. Conclusions: There is a paucity of guidance in the field for working with transgender individuals. This article represents a step forward in the dialog and we look forward to future research that develops appropriate normative information, increases understanding of psychosocial factors, and better appreciates the range of hormonal influences for transgender individuals.     

Bella and the white water rapids

Abstract

This article is an exploration of the feeling state engendered in the art psychotherapist when working with a child who had been emotionally and sexually abused. It attempts to discover the meaning of what happened in a therapy when no verbal or thinking interaction could initially take place. It describes the difficulty of finding a way to articulate the fragmented information available, both to bring to consciousness the snippets of memory presented, and to structure them into an organised story.

Thinking appeared to be what the child was desperate to avoid. It was far too painful for her, so anger and abuse were used as a defence. Noise was produced during therapy, so that the artwork, the games and in particular the experience of projective identification could not be thought about. The noise often led to the art psychotherapist being silenced and also unable to think.

Countertransference feelings were communicated, including shame, hatred, love and fear. These were explored to help find meaning, which led to understanding that the child needed to experience attachment to a constant and non-retaliatory Other. This made the experience of both merging and separation from the therapist an enabling space in which to find symbol and thought.