Diversity of Flowering Responses in Wild Arabidopsis thaliana Strains

Although multiple environmental cues regulate the transition to flowering in Arabidopsis thaliana, previous studies have suggested that wild A. thaliana accessions fall primarily into two classes, distinguished by their requirement for vernalization (extended winter-like temperatures), which enables rapid flowering under long days. Much of the difference in vernalization response is apparently due to variation at two epistatically acting loci, FRI and FLC. We present the response of over 150 wild accessions to three different environmental variables. In long days, FLC is among those genes whose expression is most highly correlated with flowering. In short days, FRI and FLC are less important, although their contribution is still significant. In addition, there is considerable variation not only in vernalization response, but also in the response to differences in day length or ambient growth temperature. The identification of accessions that flower relatively early or late in specific environments suggests that many of the flowering-time pathways identified by mutagenesis, such as those that respond to day length, contribute to flowering-time variation in the wild. In contrast to differences in vernalization requirement, which are mainly mediated by FRI and FLC, it seems that variation in these other pathways is due to allelic effects at several different loci

Bleeding from ruptured hepatic metastases as a cause of syncope in an octogenarian: a case report

<p>Abstract</p> <p>Introduction</p> <p>Acute hemoperitoneum as a result of hemorrhage from liver metastases is an uncommon but serious condition. The use of appropriate imaging is important in the diagnosis and can have a profound impact on subsequent management. This case is important because the presentation was of recurrent syncopal episodes with an unusual underlying cause. This case highlights the need to consider this diagnosis in the differential in patients presenting with collapse in the acute setting.</p> <p>Case presentation</p> <p>We present the case of an 85-year-old Caucasian man who was admitted following a collapse episode and was found to be persistently hypotensive despite aggressive resuscitation. An acute intra-peritoneal bleed originating from hepatic metastases from an unknown primary was identified promptly with computed tomography imaging and was subsequently managed conservatively.</p> <p>Conclusions</p> <p>This case aims to convey key teaching points: (A) the need to consider intra-abdominal hemorrhage in the differential diagnosis when assessing patients with collapse; and (B) the use of appropriate imaging such as computed tomography can facilitate a prompt diagnosis and appropriate management steps can then be taken accordingly.</p

Understanding the threats posed by non-native species: public vs. conservation managers.

Public perception is a key factor influencing current conservation policy. Therefore, it is important to determine the influence of the public, end-users and scientists on the prioritisation of conservation issues and the direct implications for policy makers. Here, we assessed public attitudes and the perception of conservation managers to five non-native species in the UK, with these supplemented by those of an ecosystem user, freshwater anglers. We found that threat perception was not influenced by the volume of scientific research or by the actual threats posed by the specific non-native species. Media interest also reflected public perception and vice versa. Anglers were most concerned with perceived threats to their recreational activities but their concerns did not correspond to the greatest demonstrated ecological threat. The perception of conservation managers was an amalgamation of public and angler opinions but was mismatched to quantified ecological risks of the species. As this suggests that invasive species management in the UK is vulnerable to a knowledge gap, researchers must consider the intrinsic characteristics of their study species to determine whether raising public perception will be effective. The case study of the topmouth gudgeon Pseudorasbora parva reveals that media pressure and political debate has greater capacity to ignite policy changes and impact studies on non-native species than scientific evidence alone

Early Developmental Responses to Seedling Environment Modulate Later Plasticity to Light Spectral Quality

Correlations between developmentally plastic traits may constrain the joint evolution of traits. In plants, both seedling de-etiolation and shade avoidance elongation responses to crowding and foliage shade are mediated by partially overlapping developmental pathways, suggesting the possibility of pleiotropic constraints. To test for such constraints, we exposed inbred lines of Impatiens capensis to factorial combinations of leaf litter (which affects de-etiolation) and simulated foliage shade (which affects phytochrome-mediated shade avoidance). Increased elongation of hypocotyls caused by leaf litter phenotypically enhanced subsequent elongation of the first internode in response to low red∶far red (R∶FR). Trait expression was correlated across litter and shade conditions, suggesting that phenotypic effects of early plasticity on later plasticity may affect variation in elongation traits available to selection in different light environments

Critical Indices as Limits of Control Functions

A variant of self-similar approximation theory is suggested, permitting an easy and accurate summation of divergent series consisting of only a few terms. The method is based on a power-law algebraic transformation, whose powers play the role of control functions governing the fastest convergence of the renormalized series. A striking relation between the theory of critical phenomena and optimal control theory is discovered: The critical indices are found to be directly related to limits of control functions at critical points. The method is applied to calculating the critical indices for several difficult problems. The results are in very good agreement with accurate numerical data.Comment: 1 file, 5 pages, RevTe

Far-infrared study of the Jahn-Teller distorted C60 monoanion in C60 tetraphenylphosphoniumiodide

We report high-resolution far-infrared transmission measurements on C(60)-tetraphenylphosphoniumiodide as a function of temperature. In the spectral region investigated (20-650 cm(-1)), we assign intramolecular modes of the C(60) monoanion and identify low-frequency combination modes. The well-known F(1u)(1) and F(1u)(2) modes are split into doublers at room temperature, indicating a D(5d) or D(3d) distorted ball. This result is consistent with a dynamic Jahn-Teller effect in the strong-coupling limit or with a static distortion stabilized by low-symmetry perturbations. The appearance of silent odd modes is in keeping with symmetry reduction of the hall, while activation of even modes is attributed to interband electron-phonon coupling and orientational disorder in the fulleride salt. Temperature dependences reveal a weak transition in the region 125-150 K in both C(60)(-) and counterion modes, indicating a bulk, rather than solely molecular, effect. Anomalous softening (with decreasing temperature) in several modes may correlate with the radial character of those vibrations. [S0163-1829(98)03245-7]

INSPIRE: A phase III study of the BLP25 liposome vaccine (L-BLP25) in Asian patients with unresectable stage III non-small cell lung cancer

<p>Abstract</p> <p>Background</p> <p>Previous research suggests the therapeutic cancer vaccine L-BLP25 potentially provides a survival benefit in patients with locally advanced unresectable stage III non-small cell lung carcinoma (NSCLC). These promising findings prompted the phase III study, INSPIRE, in patients of East-Asian ethnicity. East-Asian ethnicity is an independent favourable prognostic factor for survival in NSCLC. The favourable prognosis is most likely due to a higher incidence of EGFR mutations among this patient population.</p> <p>Methods/design</p> <p>The primary objective of the INSPIRE study is to assess the treatment effect of L-BLP25 plus best supportive care (BSC), as compared to placebo plus BSC, on overall survival time in East-Asian patients with unresectable stage III NSCLC and either documented stable disease or an objective response according to the Response Evaluation Criteria in Solid Tumors (RECIST) criteria following primary chemoradiotherapy. Those in the L-BLP25 arm will receive a single intravenous infusion of cyclophosphamide (300 mg/m²) 3 days before the first L-BLP25 vaccination, with a corresponding intravenous infusion of saline to be given in the control arm. A primary treatment phase of 8 subcutaneous vaccinations of L-BLP25 930 μg or placebo at weekly intervals will be followed by a maintenance treatment phase of 6-weekly vaccinations continued until disease progression or discontinuation from the study.</p> <p>Discussion</p> <p>The ongoing INSPIRE study is the first large study of a therapeutic cancer vaccine specifically in an East-Asian population. It evaluates the potential of maintenance therapy with L-BLP25 to prolong survival in East-Asian patients with stage III NSCLC where there are limited treatment options currently available.</p> <p>Study number</p> <p>EMR 63325-012</p> <p>Trial Registration</p> <p>Clinicaltrials.gov reference: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01015443">NCT01015443</a></p

Bacterial adaptation is constrained in complex communities

© 2020, The Author(s). A major unresolved question is how bacteria living in complex communities respond to environmental changes. In communities, biotic interactions may either facilitate or constrain evolution depending on whether the interactions expand or contract the range of ecological opportunities. A fundamental challenge is to understand how the surrounding biotic community modifies evolutionary trajectories as species adapt to novel environmental conditions. Here we show that community context can dramatically alter evolutionary dynamics using a novel approach that ‘cages’ individual focal strains within complex communities. We find that evolution of focal bacterial strains depends on properties both of the focal strain and of the surrounding community. In particular, there is a stronger evolutionary response in low-diversity communities, and when the focal species have a larger genome and are initially poorly adapted. We see how community context affects resource usage and detect genetic changes involved in carbon metabolism and inter-specific interaction. The findings demonstrate that adaptation to new environmental conditions should be investigated in the context of interspecific interactions

T Cells' Immunological Synapses Induce Polarization of Brain Astrocytes In Vivo and In Vitro: A Novel Astrocyte Response Mechanism to Cellular Injury

Astrocytes usually respond to trauma, stroke, or neurodegeneration by undergoing cellular hypertrophy, yet, their response to a specific immune attack by T cells is poorly understood. Effector T cells establish specific contacts with target cells, known as immunological synapses, during clearance of virally infected cells from the brain. Immunological synapses mediate intercellular communication between T cells and target cells, both in vitro and in vivo. How target virally infected astrocytes respond to the formation of immunological synapses established by effector T cells is unknown.Herein we demonstrate that, as a consequence of T cell attack, infected astrocytes undergo dramatic morphological changes. From normally multipolar cells, they become unipolar, extending a major protrusion towards the immunological synapse formed by the effector T cells, and withdrawing most of their finer processes. Thus, target astrocytes become polarized towards the contacting T cells. The MTOC, the organizer of cell polarity, is localized to the base of the protrusion, and Golgi stacks are distributed throughout the protrusion, reaching distally towards the immunological synapse. Thus, rather than causing astrocyte hypertrophy, antiviral T cells cause a major structural reorganization of target virally infected astrocytes.Astrocyte polarization, as opposed to hypertrophy, in response to T cell attack may be due to T cells providing a very focused attack, and thus, astrocytes responding in a polarized manner. A similar polarization of Golgi stacks towards contacting T cells was also detected using an in vitro allogeneic model. Thus, different T cells are able to induce polarization of target astrocytes. Polarization of target astrocytes in response to immunological synapses may play an important role in regulating the outcome of the response of astrocytes to attacking effector T cells, whether during antiviral (e.g. infected during HIV, HTLV-1, HSV-1 or LCMV infection), anti-transplant, autoimmune, or anti-tumor immune responses in vivo and in vitro