Allometry and growth of eight tree taxa in United Kingdom woodlands.

This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0As part of a project to develop predictive ecosystem models of United Kingdom woodlands we have collated data from two United Kingdom woodlands - Wytham Woods and Alice Holt. Here we present data from 582 individual trees of eight taxa in the form of summary variables relating to the allometric relationships between trunk diameter, height, crown height, crown radius and trunk radial growth rate to the tree's light environment and diameter at breast height. In addition the raw data files containing the variables from which the summary data were obtained. Large sample sizes with longitudinal data spanning 22 years make these datasets useful for future studies concerned with the way trees change in size and shape over their life-span

Pharmacological management of unipolar depression

Objective : To be used in conjunction with ‘Psychological management of unipolar depression’ [Lampe et al. Acta Psychiatr Scand 2013;127(Suppl. 443):24–37] and ‘Lifestyle management of unipolar depression’ [Berk et al. Acta Psychiatr Scand 2013;127(Suppl. 443):38–54]. To provide clinically relevant recommendations for the use of pharmacological treatments in depression derived from a literature review.Method : Using our previous Clinical Practice Guidelines [Malhi et al. Clinical practice recommendations for bipolar disorder. Acta Psychiatr Scand 2009;119(Suppl. 439):27–46] as a foundation, these clinician guidelines target key practical considerations when prescribing pharmacotherapy. A comprehensive review of the literature was conducted using electronic database searches (PubMed, MEDLINE), and the findings have been synthesized and integrated alongside clinical experience.Results : The pharmacotherapy of depression is an iterative process that often results in partial and non-response. Beyond the initiation of antidepressants, the options within widely used strategies, such as combining agents and switching between agents, are difficult to proscribe because of the paucity of pertinent research. However, there is some evidence for second-line strategies, and a non-prescriptive algorithm can be derived that is based broadly on principles rather than specific steps.Conclusion : Depression is by its very nature a heterogeneous illness that is consequently difficult to treat. Invariably, situation-specific factors often play a significant role and must be considered, especially in the case of partial and non-response. Consulting with colleagues and trialling alternate treatment paradigms are essential strategies in the management of depression

Future Climate and Land Use Change Impacts on River Flows in the Tapajós Basin in the Brazilian Amazon

Abstract Land conversion and changing climate are expected to significantly alter tropical forest hydrology. We used a land surface model integrated with a river routing scheme to analyze the hydrological alterations expected in the Tapajós River basin, a large portion of the Brazilian Amazon, caused by two environmental drivers: climate and land use. The model was forced with two future climate scenarios (years 2026–2045) from the Earth System Model HadGem2‐ES with moderate (+4.5 W/m2 radiative forcing value in the year 2100 with respect to preindustrial levels) and severe (+8.5 W/m2) representative atmospheric carbon dioxide pathways (Representative Concentration Pathways). We tested the sensitivity of our results to the uncertainty in future climate projections by running simulations with IPSL‐CM5 (wettest scenarios) and GISS‐E2 (driest scenarios). Human land use effects on vegetation were evaluated using a limited and an extreme deforestation scenario. Our analysis indicates that climate change is predicted to reduce river flows across seasons (up to 20%) and bring a considerable shift in flow seasonality toward a later onset (nearly 1.5 months) and increase in interannual variability. While land use change partially counteracts the climate‐driven diminishing trend in river flows, it is expected to contribute to a further increase in interannual and intraannual variability. From a water management perspective, the overall reduction of river flows and their increased variability, combined with the shift and the shortening of the wet season, could potentially affect the productivity of the large hydropower systems planned for the region and the growing demand for agricultural and transport expansion

Pattern and process in Amazon tree turnover, 1976-2001

Previous work has shown that tree turnover, tree biomass and large liana densities have increased in mature tropical forest plots in the late twentieth century. These results point to a concerted shift in forest ecological processes that may already be having significant impacts on terrestrial carbon stocks, fluxes and biodiversity. However, the findings have proved controversial, partly because a rather limited number of permanent plots have been monitored for rather short periods. The aim of this paper is to characterize regional-scale patterns of 'tree turnover' (the rate with which trees die and recruit into a population) by using improved datasets now available for Amazonia that span the past 25 years. Specifically, we assess whether concerted changes in turnover are occurring, and if so whether they are general throughout the Amazon or restricted to one region or environmental zone. In addition, we ask whether they are driven by changes in recruitment, mortality or both. We find that: (i) trees 10 cm or more in diameter recruit and die twice as fast on the richer soils of southern and western Amazonia than on the poorer soils of eastern and central Amazonia; (ii) turnover rates have increased throughout Amazonia over the past two decades; (iii) mortality and recruitment rates have both increased significantly in every region and environmental zone, with the exception of mortality in eastern Amazonia; (iv) recruitment rates have consistently exceeded mortality rates; (v) absolute increases in recruitment and mortality rates are greatest in western Amazonian sites; and (vi) mortality appears to be lagging recruitment at regional scales. These spatial patterns and temporal trends are not caused by obvious artefacts in the data or the analyses. The trends cannot be directly driven by a mortality driver (such as increased drought or fragmentation-related death) because the biomass in these forests has simultaneously increased. Our findings therefore indicate that long-acting and widespread environmental changes are stimulating the growth and productivity of Amazon forests

Chaco Canyon Dig Unearths Ethical Concerns

The field of paleogenomics (the study of ancient genomes) is rapidly advancing with more robust methods of isolating ancient DNA and increasing access to next-generation DNA sequencing technology. As these studies progress, many important ethical issues have emerged that should be considered when ancient Native American remains, whom we refer to as ancestors, are used in research. We highlight a recent article by Kennett et al. (2017), “Archaeogenomic evidence reveals prehistoric matrilineal dynasty,” that brings several ethical issues to light that should be addressed in paleogenomics research (Kennett et al. 2017). The study helps elucidate the matrilineal relationships in ancient Chacoan society through ancient DNA analysis. However, we, as Indigenous researchers and allies, raise ethical concerns with the study’s scientific conclusions that can be problematic for Native American communities: (1) the lack of tribal consultation, (2) the use of culturally-insensitive descriptions, and (3) the potential impact on marginalized groups. Further, we explore the limitations of the Native American Graves Protection and Repatriation Act (NAGPRA), which addresses repatriation but not research, as clear ethical guidelines have not been established for research involving Native American ancestors, especially those deemed “culturally unaffiliated”. As multiple studies of culturally unaffiliated remains have been initiated recently, it is imperative that researchers consider the ethical ramifications of paleogenomics research. Past research indiscretions have created a history of mistrust and exploitation in many Native American communities. To promote ethical engagement of Native American communities in research, we therefore suggest careful attention to the ethical considerations, strong tribal consultation requirements, and greater collaborations amongst museums, federal agencies, researchers, scientific journals, and granting agencies

Nitrogen cycling and budget in crop rotations as influenced by preceding crops and N fertilization

Non-Peer Reviewe

The modern pollen-vegetation relationship of a tropical forest-savannah mosaic landscape, Ghana, West Africa

Transitions between forest and savannah vegetation types in fossil pollen records are often poorly understood due to over-production by taxa such as Poaceae and a lack of modern pollen-vegetation studies. Here, modern pollen assemblages from within a forest-savannah transition in West Africa are presented and compared, their characteristic taxa discussed, and implications for the fossil record considered. Fifteen artificial pollen traps were deployed for 1 year, to collect pollen rain from three vegetation plots within the forest-savannah transition in Ghana. High percentages of Poaceae and Melastomataceae/Combretaceae were recorded in all three plots. Erythrophleum suaveolens characterised the forest plot, Manilkara obovata the transition plot and Terminalia the savannah plot. The results indicate that Poaceae pollen influx rates provide the best representation of the forest-savannah gradient, and that a Poaceae abundance of >40% should be considered as indicative of savannah-type vegetation in the fossil record

Lack of cortico-limbic coupling in bipolar disorder and schizophrenia during emotion regulation

Bipolar disorder (BD) and schizophrenia (Sz) share dysfunction in prefrontal inhibitory brain systems, yet exhibit distinct forms of affective disturbance. We aimed to distinguish these disorders on the basis of differential activation in cortico-limbic pathways during voluntary emotion regulation. Patients with DSM-IV diagnosed Sz (12) or BD-I (13) and 15 healthy control (HC) participants performed a well-established emotion regulation task while undergoing functional magnetic resonance imaging. The task required participants to voluntarily upregulate or downregulate their subjective affect while viewing emotionally negative images or maintain their affective response as a comparison condition. In BD, abnormal overactivity (hyperactivation) occurred in the right ventrolateral prefrontal cortex (VLPFC) during up- and downregulation of negative affect, relative to HC. Among Sz, prefrontal hypoactivation of the right VLPFC occurred during downregulation (opposite to BD), whereas upregulation elicited hyperactivity in the right VLPFC similar to BD. Amygdala activity was significantly related to subjective negative affect in HC and BD, but not Sz. Furthermore, amygdala activity was inversely coupled with the activity in the left PFC during downregulation in HC (r=−0.76), while such coupling did not occur in BD or Sz. These preliminary results indicate that differential cortico-limbic activation can distinguish the clinical groups in line with affective disturbance: BD is characterized by ineffective cortical control over limbic regions during emotion regulation, while Sz is characterized by an apparent failure to engage cortical (hypofrontality) and limbic regions during downregulation

Cell arrest and cell death in mammalian preimplantation development

The causes, modes, biological role and prospective significance of cell death in preimplantation development in humans and other mammals are still poorly understood. Early bovine embryos represent a very attractive experimental model for the investigation of this fundamental and important issue. To obtain reference data on the temporal and spatial occurrence of cell death in early bovine embryogenesis, three-dimensionally preserved embryos of different ages and stages of development up to hatched blastocysts were examined in toto by confocal laser scanning microscopy. In parallel, transcript abundance profiles for selected apoptosis-related genes were analyzed by real-time reverse transcriptase-polymerase chain reaction. Our study documents that in vitro as well as in vivo, the first four cleavage cycles are prone to a high failure rate including different types of permanent cell cycle arrest and subsequent non-apoptotic blastomere death. In vitro produced and in vivo derived blastocysts showed a significant incidence of cell death in the inner cell mass (ICM), but only in part with morphological features of apoptosis. Importantly, transcripts for CASP3, CASP9, CASP8 and FAS/FASLG were not detectable or found at very low abundances. In vitro and in vivo, errors and failures of the first and the next three cleavage divisions frequently cause immediate embryo death or lead to aberrant subsequent development, and are the main source of developmental heterogeneity. A substantial occurrence of cell death in the ICM even in fast developing blastocysts strongly suggests a regular developmentally controlled elimination of cells, while the nature and mechanisms of ICM cell death are unclear. Morphological findings as well as transcript levels measured for important apoptosis-related genes are in conflict with the view that classical caspase-mediated apoptosis is the major cause of cell death in early bovine development

Mitochondrial echoes of first settlement and genetic continuity in El Salvador

Background: From Paleo-Indian times to recent historical episodes, the Mesoamerican isthmus played an important role in the distribution and patterns of variability all around the double American continent. However, the amount of genetic information currently available on Central American continental populations is very scarce. In order to shed light on the role of Mesoamerica in the peopling of the New World, the present study focuses on the analysis of the mtDNA variation in a population sample from El Salvador. Methodology/Principal Findings: We have carried out DNA sequencing of the entire control region of the mitochondrial DNA (mtDNA) genome in 90 individuals from El Salvador. We have also compiled more than 3,985 control region profiles from the public domain and the literature in order to carry out inter-population comparisons. The results reveal a predominant Native American component in this region: by far, the most prevalent mtDNA haplogroup in this country (at ~90%) is A2, in contrast with other North, Meso- and South American populations. Haplogroup A2 shows a star-like phylogeny and is very diverse with a substantial proportion of mtDNAs (45%; sequence range 16090–16365) still unobserved in other American populations. Two different Bayesian approaches used to estimate admixture proportions in El Salvador shows that the majority of the mtDNAs observed come from North America. A preliminary founder analysis indicates that the settlement of El Salvador occurred about 13,400±5,200 Y.B.P.. The founder age of A2 in El Salvador is close to the overall age of A2 in America, which suggests that the colonization of this region occurred within a few thousand years of the initial expansion into the Americas. Conclusions/Significance: As a whole, the results are compatible with the hypothesis that today's A2 variability in El Salvador represents to a large extent the indigenous component of the region. Concordant with this hypothesis is also the observation of a very limited contribution from European and African women (~5%). This implies that the Atlantic slave trade had a very small demographic impact in El Salvador in contrast to its transformation of the gene pool in neighbouring populations from the Caribbean facade