High temperature stress and flowering in brassica napus L.

High temperature stress (HTS) adversely affects reproduction in most plant species studied to date. HTS during flowering may result in an almost total inhibition of seed production in crop plants. Increasing our knowledge of the effects of HTS on seed production will aid the breeding of more thermotolerant crop plants and improve our understanding of the effects of stress on plants. An investigation of the effects of both drought and high temperature stress on the yields of barley, canola, flax, durum and spring wheat in five locations in Saskatchewan over a 25-year period was performed using multivariate analysis. Higher temperatures during June and July, when the plants were flowering, were correlated with reductions in yields of all the crops studied (except barley in June). A positive correlation between yields and precipitation during May and the winter preceding the growing season was observed.In growth chambers, Brassica napus silique and seed production were inhibited during a ramping HTS treatment. This was due to a decrease in pollen germinability rather than a reduction in the number of flowers produced. HTS also caused reductions in megagametophyte fertility and disrupted embryo and/or seed development.Transgenic plants were developed to overcome the effects of HTS on seed production. Two DNA constructs, one with the Arabidopsis thaliana LEAFY (AtLFY) promoter controlling A. thaliana HEAT SHOCK PROTEIN 101 (AtHSP101) ORF expression and another with the AtHSP101 promoter controlling AtLFY ORF expression, were inserted into B. napus. Other DNA constructs were made, using the constitutively expressed Cauliflower Mosaic Virus 35S or the synthetic EntCup4 promoters to control expression of the AtHSP101 or A. thaliana HEAT SHOCK TRANSCRIPTION FACTOR 3 (AtHSF3) ORFs. These constructs were inserted into both B. napus and A. thaliana. Transgenic plants were tested using a ramping temperature regime but were found not to have increased flower thermotolerance. During the manufacture of the DNA constructs it was determined that, in A. thaliana, 573 bp of AtHSP101 had been copied between Terminal Inverted Repeats of a Mu-Like Element (MULE). This fragment was named HSP101B. In some transgenic B. napus and A. thaliana lines, containing 2046 bp of the HSP101B upstream regulatory region controlling B-glucuronidase (GUS) expression, cold-inducible GUS expression was observed. Methylation may have a role in control of endogenous HSP101B transcription

A comment on "Amplification of endpoint structure for new particle mass measurement at the LHC"

We present a comment on the kinematic variable $m_{CT2}$ recently proposed in "Amplification of endpoint structure for new particle mass measurement at the LHC". The variable is designed to be applied to models such as R-parity conserving Supersymmetry (SUSY) when there is pair production of new heavy particles each of which decays to a single massless visible and a massive invisible component. It was proposed in "Amplification of endpoint structure for new particle mass measurement at the LHC" that a measurement of the peak of the $m_{CT2}$ distribution could be used to precisely constrain the masses of the SUSY particles. We show that when Standard Model backgrounds are included in simulations, the sensitivity of the $m_{CT2}$ variable to the SUSY particle masses is more seriously impacted for $m_{CT2}$ than for other previously proposed variables.Comment: 5 page

A matrix isolation and computational study of molecular palladium fluorides : does PdF₆ exist?

Palladium atoms generated by thermal evaporation and laser ablation were reacted with and trapped in F₂ /Ar, F₂ /Ne, and neat F₂ matrices. The products were characterized by electronic absorption and infrared spectroscopy, together with relativistic density functional theory calculations as well as coupled cluster calculations. Vibrational modes at 540 and 617 cm⁻¹ in argon matrices were assigned to molecular PdF and PdF₂ , and a band at 692 cm⁻¹ was assigned to molecular PdF₄ . A band at 624 cm⁻¹ can be assigned to either PdF₃ or PdF₆, with the former preferred from experimental considerations. Although calculations might support the latter assignment, our conclusion is that in these detailed experiments there is no convincing evidence for PdF₆

How efficient are seeding operations : Kondinin work study

The efficiency of machinery and labour during seeding operations was studied in 1977 by the Kondinin and Districts Farm Improvement Group and the Department of Agriculture. The aim was to find what influenced efficiency during cropping. Time spent on activities during the working day was measured, and it was found that repairs, maintenance, meals and other incidental jobs considerably reduced the time spent driving the tractor. Each farmer participating in the study was given the results of his own farm compared to the group, indicating tasks most needing improvement

The HCV Core Protein Acts as a Positive Regulator of Fas-Mediated Apoptosis in a Human Lymphoblastoid T Cell Line

AbstractHepatitis C virus (HCV) is a major human pathogen causing mild to severe liver disease worldwide and is remarkably efficient at establishing persistent infections. Previously, we have shown that the core protein has an immunomodulatory function including the suppression of T lymphocyte responses to viral infection. To investigate the underlying mechanism for the role of core protein in immune modulation, we examined the effect of core on the sensitivity of the human T cell line, Jurkat, to Fas-mediated apoptosis. The transient and stable expression of core protein in Jurkat cells increased the sensitivity of cells to Fas-mediated apoptosis when compared to control cells expressing vector DNA alone. In addition, we demonstrated that the core protein binds to the cytoplasmic domain of Fas which may enhance the downstream signaling event of Fas-mediated apoptosis. The expression of core protein did not alter the cell surface expression of Fas, indicating that the increased sensitivity of core-expressing cells to Fas ligand was not due to upregulation of Fas. Furthermore, we observed the augmentation of caspase-3 activity in core-expressing cells. These results suggest that the core protein may promote the apoptosis of immune cells during HCV infection via the Fas signaling pathway, thus facilitating HCV persistence

Mapping the e-Learning Assessment Domain: Concept Maps for Orientation and Navigation

Concept or Topic Maps have long been used as a method of categorizing and organizing information about a domain. Building them can help people conceptualize an area and spot trends or gaps, and as a presentation method they quickly provide an overview and general impression of a space. We are currently constructing a Reference Model of the Assessment Domain that takes the form of a highly interlinked dynamic website. This represents the assessment domain via the software, projects, standards and use cases of which it is composed. In this paper we present our efforts to create complimentary concept maps of the assessment domain, not as an overview, but for navigation and orientation within the domain. These concept maps, which model resources and activities independently, have been corroborated with practitioners in the e-learning community

A study of the photometric variability of the peculiar magnetic white dwarf WD1953-011

We present and interpret simultaneous new photometric and spectroscopic observations of the peculiar magnetic white dwarf WD1953-011. The flux in the V-band filter and intensity of the Balmer spectral lines demonstrate variability with the rotation period of about 1.45 days. According to previous studies, this variability can be explained by the presence of a dark spot having a magnetic nature, analogous to a sunspot. Motivated by this idea, we examine possible physical relationships between the suggested dark spot and the strong-field magnetic structure (magnetic "spot", or "tube") recently identified on the surface of this star. Comparing the rotationally-modulated flux with the variable spectral observables related to the magnetic "spot" we establish their correlation, and therefore their physical relationship. Modeling the variable photometric flux assuming that it is associated with temperature variations in the stellar photosphere, we argue that the strong-field area and dark, low-temperature spot are comparable in size and located at the same latitudes, essentially overlapping each other with a possible slight longitudinal shift. In this paper we also present a new, improved value of the star's rotational period and constrain the characteristics of the thermal inhomogeneity over the degenerate's surface.Comment: accepted to the Ap

High-performance pipeline for MutMap and QTL-seq

[Summary] Bulked segregant analysis implemented in MutMap and QTL-seq is a powerful and efficient method to identify loci contributing to important phenotypic traits. However, the previous pipelines were not user-friendly to install and run. Here, we describe new pipelines for MutMap and QTL-seq. These updated pipelines are approximately 5–8 times faster than the previous pipeline, are easier for novice users to use, and can be easily installed through bioconda with all dependencies. [Availability] The new pipelines of MutMap and QTL-seq are written in Python and can be installed via bioconda. The source code and manuals are available online (MutMap: https://github.com/YuSugihara/MutMap, QTL-seq: https://github.com/YuSugihara/QTL-seq)

How Do Tidal Volume and Peep Settings Affect Expiratory Resistance? A Bench Study of the LTV® 1200 Homecare Ventilator

Background: Home care ventilators hold a prominent place in the world of mechanical ventilation, and careful selection of ventilator modes and settings profoundly impact patient outcomes. In addition to patient factors, exhalation valves can generate expiratory resistance (ER) and can increase work-of-breathing and contribute to auto-PEEP. Analyzing ER on new homecare ventilators is crucial to patient care. The purpose of this study is to analyze the affects of tidal volume (Vt) and PEEP on ER on the Pulmonetic LTV® 1200 homecare ventilator. Method: ER was measured on the Pulmonetic LTV® 1200 (LTV) homecare ventilator. The LTV was attached to the Hans Rudolph Electronic Breathing Simulator (HR 1101) using Pulmonetic’s non-heated circuit. Pressure and flow transducers (Hans Rudolph 4700 series) were calibrated using DT Foundry software and a Downs CPAP generator. Both transducers were placed before the exhalation valve, and ER was calculated using the equation (P1-P2/V). P1 = pressure before the exhalation valve, P2 = ambient pressure after the exhalation valve, and V = flow in liters per second. The ventilator was placed in volume A/C mode, frequency 12 breaths/minute, using tidal volumes (Vt) of 300, 500, 700, and 900 mL, ER was measured and recorded at each change. This process was repeated with set PEEP levels of 8, 11, and 14 cmH2O. Results: See Table 1. Conclusion: As expected, this study found that ER changed when Vt and PEEP were manipulated. The values for ER in this study are consistent with previous studies which reported ER values of 2.1 – 159.0 cmH2O/L/sec for modern intensive care ventilators. The apparent inconsistency of expiratory resistance values at Vt 500 ml and 900 ml was possibly due to a defect in sampling methods--insufficient time devoted to letting the LTV stabilize after adjusting Vt. Future studies should utilize a longer sampling period. Overall, additional studies are necessary to thoroughly evaluate expiratory resistance in the clinical setting since patient variables may also impact expiratory resistance