Growth and root inhibition in Axenic hydrilla verticillata cultures

Hydrilla verticillata Royle is a submersed aquatic weed infesting waterways throughout the world. Hydrilla was introduced into the United States in 196 and has spread across the southern states. Hydrilla has extensive reproductive capacity, spreading by seeds, axillary and subterranean vegetative buds, fragmentation, and stolons. Subterranean buds, called tubers, are the predominant form of reproduction. This reproductive potential has made mechanical, chemical, and biological control largely ineffective. To study the life cycle of Hydrilla, Elaine and Ward (1981) developed a method for producing axenic cultures from tubers. The process by which axenic cultures were produced involves surface treatment of the tuber with sodium hypochlorite and removal of outer bud scales. Tubers were grown in a mineral salts media containing 15 ug/ml penicillin and 1 ug/ml streptomycin to prevent bacterial growth. Two percent glucose and .5 per cent casein were added to facilitate detection of bacterial contamination. Axenic cultures produced by this method have inhibited shoot and root growth. In the present study, different variables in the process were analyzed for inhibitory effects. Addition of yeast extract, IAA, IBA, GAg, and kinetin failed to overcome stem or root growth inhibition. Neither NaOCl treatment nor dissection as separate factors affected growth or root development. Sodium hypochlorite treatment followed by dissection resulted in retarded growth at times, although mature plants did develop. Addition of penicillin and streptomycin or penicillin, streptomycin, glucose, and casein resulted in inhibited growth and root production. Casein and streptomycin both inhibited stem and root growth in all cases. Glucose slightly enhanced growth. Penicillin had no significant effects on shoot growth or root formation and growth. Axenic cultures with penicillin and glucose exhibited no inhibitions. Streptomycin inhibits growth of roots at 15, 5, and 1 ug/ml. Penicillin did not affect growth of stems or roots at 25, 75, or 15 ug/ml but did not effectively control bacteria. Neomycin, ampicillin, tetracycline, and chloramphenicol were tested separately at 25, 75, and 15 ug/ml and in combinations at 75 ug/ml as possible alternatives to streptomycin. All were inhibitory to shoot growth. Root formation was significantly inhibited by all concentrations of chloramphenicol, and the higher concentrations of neomycin and tetracycline. Several of the antibiotic combinations, tested in conjunction with 25 ug/ml penicillin, were effective against bacteria but were inhibitory to hydrilla growth at tested concentrations

The Population Biology and Demography of \u3cem\u3eCimicifuga rubifolia\u3c/em\u3e Kearney and the Genetic Relationships Among North American \u3cem\u3eCimicifuga\u3c/em\u3e Species

In this beginning study of the population biology of Cimicifuga species, the life history and demography of the long-lived herbaceous perennial, Cimicifuga rubifolia Kearney, were investigated, the genetic structure of some of its populations was studied, and an investigation of the genetic relationships among the North American species was begun. The life history and demography were monitored in two populations, one of approximately 1400 individuals (1987-1990) and the second of about 400 individuals (1988-1990). A model of leaf area was used to determine the leaf area (photosynthetic size) of individuals and this was followed during the study. Relationships between the leaf area of the individuals and flowering, fruit set, mortality, dormancy and size change were investigated. The population size structures were considered using size class transition matrices. Population genetic structure from throughout the range of Cimicifug rubifolia was assayed using starch gel electrophoresis, and the genetic relationships of the North American Cimicifuga species were studied using electrophoretic methods. Leaf area was positively related to the ability to flower and set seed while mortality and dormancy were negatively related to leaf area. Reproduction was primarily sexual, with asexual reproduction by rhizome fragmentation occurring rarely. Several plant responses thought to be related to the low precipitation amounts during 1987 and 1988 were noted. The mean size of the plants in both populations increased by approximately 30 percent during the study and the size at which the probability of flowering reached 50 percent varied. Size structure based on size transition probabilities, was not constant. Plant dormancy was frequent and the number of seedlings noted yearly varied widely. Seven loci were assayed electrophoretically in C. rubifolia. Accumulated gene differences per locus, as measured by genetic distance among populations was insubstantial but, genetic divergence among the populations is indicated by large FST values (.197-.468). This appears to be due to reproductive isolation of populations, indicated by high total fixation indices. Gene flow within populations seems to be limited. The ten loci assayed in 6 North American species of Cimicifuga showed the mean genetic identity from pairwise comparisons of the species to be .543. Mean GST values ranged from .086 to .503 and seem to be related, in part, to varying breeding systems among the species

Multiple barriers to obtaining child support : experiences of women leaving violent partners

This article reports on a study which explores how policies and practices shape the experiences of single parents when seeking and using child support from violent ex-partners. The findings of this and similar research studies on violence, child support and poverty indicate that the receipt of child support is a multi-step process plagued with multiple barriers.<br /

A randomised controlled trial of a complex intervention to reduce children’s exposure to secondhand smoke in the home

Objectives: Exposing children to secondhand tobacco smoke (SHS) causes significant harm and occurs predominantly through smoking by caregivers in the family home. We report a trial of a complex intervention designed to reduce secondhand smoke exposure of children whose primary caregiver feels unable or unwilling to quit smoking. Design: An open-label, parallel, randomised controlled trial. Setting: Deprived communities in Nottingham City and County, England Participants: Caregivers resident in Nottingham City and County in England who were at least 18 years old, the main caregiver of a child aged under 5 years living in their household, and reported that they were smoking tobacco inside their home. Interventions: We compared a complex intervention combining personalised feedback on home air quality, behavioural support and nicotine replacement therapy for temporary abstinence with usual care. Main outcomes: The primary outcome was change in air quality in the home, measured as average 16–24 hours levels of particulate matter of <2.5 µm diameter (PM2.5), between baseline and 12 weeks. Secondary outcomes included changes in maximum PM2.5, proportion of time PM2.5 exceeded WHO recommended levels of maximum exposure of 25 µg/mg3, child salivary cotinine, caregivers’ cigarette consumption, nicotine dependence, determination to stop smoking, quit attempts and quitting altogether during the intervention. Results: Geometric mean PM2.5 decreased significantly more (by 35.2%; 95% CI 12.7% to 51.9%) in intervention than in usual care households, as did the proportion of time PM2.5 exceeded 25 µg/mg3, child salivary cotinine concentrations, caregivers’ cigarette consumption in the home, nicotine dependence, determination to quit and likelihood of having made a quit attempt. Conclusions: By reducing exposure to SHS in the homes of children who live with smokers unable or unwilling to quit, this intervention offers huge potential to reduce children’s’ tobacco-related harm. Trial registration number ISRCTN81701383. This trial was funded by the UK National Institute for Health Research (NIHR): RP-PG-0608-10020 http://dx.doi.org/10.1136/tobaccocontrol-2016-05327

Ack1 Mediated AKT/PKB Tyrosine 176 Phosphorylation Regulates Its Activation

The AKT/PKB kinase is a key signaling component of one of the most frequently activated pathways in cancer and is a major target of cancer drug development. Most studies have focused on its activation by Receptor Tyrosine Kinase (RTK) mediated Phosphatidylinositol-3-OH kinase (PI3K) activation or loss of Phosphatase and Tensin homolog (PTEN). We have uncovered that growth factors binding to RTKs lead to activation of a non-receptor tyrosine kinase, Ack1 (also known as ACK or TNK2), which directly phosphorylates AKT at an evolutionarily conserved tyrosine 176 in the kinase domain. Tyr176-phosphorylated AKT localizes to the plasma membrane and promotes Thr308/Ser473-phosphorylation leading to AKT activation. Mice expressing activated Ack1 specifically in the prostate exhibit AKT Tyr176-phosphorylation and develop murine prostatic intraepithelial neoplasia (mPINs). Further, expression levels of Tyr176-phosphorylated-AKT and Tyr284-phosphorylated-Ack1 were positively correlated with the severity of disease progression, and inversely correlated with the survival of breast cancer patients. Thus, RTK/Ack1/AKT pathway provides a novel target for drug discovery

Strategies for conducting situated studies of technology use in hospitals

Ethnographic methods are widely used for understanding situated practices with technology. When authors present their data gathering methods, they almost invariably focus on the bare essentials. These enable the reader to comprehend what was done, but leave the impression that setting up and conducting the study was straightforward. Text books present generic advice, but rarely focus on specific study contexts. In this paper, we focus on lessons learnt by non-clinical researchers studying technology use in hospitals: gaining access; developing good relations with clinicians and patients; being outsiders in healthcare settings; and managing the cultural divide between technology human factors and clinical practice. Drawing on case studies across various hospital settings, we present a repertoire of ways of working with people and technologies in these settings. These include engaging clinicians and patients effectively, taking an iterative approach to data gathering and being responsive to the demands and opportunities provided by the situation. The main contribution of this paper is to make visible many of the lessons we have learnt in conducting technology studies in healthcare, using these lessons to present strategies that other researchers can take up

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

A third generation vaccine for human visceral leishmaniasis and post kala azar dermal leishmaniasis : First-in-human trial of ChAd63-KH

BACKGROUND: Visceral leishmaniasis (VL or kala azar) is the most serious form of human leishmaniasis, responsible for over 20,000 deaths annually, and post kala azar dermal leishmaniasis (PKDL) is a stigmatizing skin condition that often occurs in patients after successful treatment for VL. Lack of effective or appropriately targeted cell mediated immunity, including CD8+ T cell responses, underlies the progression of VL and progression to PKDL, and can limit the therapeutic efficacy of anti-leishmanial drugs. Hence, in addition to the need for prophylactic vaccines against leishmaniasis, the development of therapeutic vaccines for use alone or in combined immuno-chemotherapy has been identified as an unmet clinical need. Here, we report the first clinical trial of a third-generation leishmaniasis vaccine, developed intentionally to induce Leishmania-specific CD8+ T cells. METHODS: We conducted a first-in-human dose escalation Phase I trial in 20 healthy volunteers to assess the safety, tolerability and immunogenicity of a prime-only adenoviral vaccine for human VL and PKDL. ChAd63-KH is a replication defective simian adenovirus expressing a novel synthetic gene (KH) encoding two Leishmania proteins KMP-11 and HASPB. Uniquely, the latter was engineered to reflect repeat domain polymorphisms and arrangements identified from clinical isolates. We monitored innate immune responses by whole blood RNA-Seq and antigen specific CD8+ T cell responses by IFNγ ELISPOT and intracellular flow cytometry. FINDINGS: ChAd63-KH was safe at intramuscular doses of 1x1010 and 7.5x1010 vp. Whole blood transcriptomic profiling indicated that ChAd63-KH induced innate immune responses characterized by an interferon signature and the presence of activated dendritic cells. Broad and quantitatively robust CD8+ T cell responses were induced by vaccination in 100% (20/20) of vaccinated subjects. CONCLUSION: The results of this study support the further development of ChAd63-KH as a novel third generation vaccine for VL and PKDL. TRIAL REGISTRATION: This clinical trial (LEISH1) was registered at EudraCT (2012-005596-14) and ISRCTN (07766359)