Growth and Lipid Content of Osmo-Tolerant and Sensitive Algae

Drought tolerance in a number of crop species has been correlated with changes in and composition of cell membrane lipids. Since membrane stability is a function of the physical properties of the lipid constituents, recent studies have focused on lipid changes in response to natural and artifically-induced water stress. Such studies have clearly shown that lipid adjustment and composition differs in drought-resistant and -tolerant species. A difficulty in working with higher plant systems is that vascular plants make structural and functional level adjustments which aid in drought resistance and which affect the process of adjustment at the cellular level. For this reason, in vitro cell culture techniques have many advantages in studying stress responses. Thus, the objectives of this research were to determine the effects of polyethylene glycol (PEG) -induced osmotic stress on the lipid and sterol composition of osmotic tolerant and susceptible species of unicellular algae belonging to the genus Chlorella

Variability monitoring of the hydroxyl maser emission in G12.889+0.489

Through a series of observations with the Australia Telescope Compact Array we have monitored the variability of ground-state hydroxyl maser emission from G12.889+0.489 in all four Stokes polarisation products. These observations were motivated by the known periodicity in the associated 6.7-GHz methanol maser emission. A total of 27 epochs of observations were made over 16 months. No emission was seen from either the 1612 or 1720 MHz satellite line transitions (to a typical five sigma upper limit of 0.2 Jy). The peak flux densities of the 1665 and 1667 MHz emission were observed to vary at a level of ~20% (with the exception of one epoch which dropped by <40%). There was no distinct flaring activity at any epoch, but there was a weak indication of periodic variability, with a period and phase of minimum emission similar to that of methanol. There is no significant variation in the polarised properties of the hydroxyl, with Stokes Q and U flux densities varying in accord with the Stokes I intensity (linear polarisation, P, varying by <20%) and the right and left circularly polarised components varying by <33% at 1665-MHz and <38% at 1667-MHz. These observations are the first monitoring observations of the hydroxyl maser emission from G12.889+0.489.Comment: 7 pages, 6 figures, accepted for publication in MNRA

12.2-GHz methanol maser MMB follow-up catalogue - I. Longitude range 330 to 10 degrees

We present a catalogue of 12.2-GHz methanol masers detected towards 6.7-GHz methanol masers observed in the unbiased Methanol Multibeam (MMB) survey in the longitude range 330\circ (through 360\circ) to 10\circ. This is the first portion of the catalogue which, when complete, will encompass all of the MMB detections. We report the detection of 184 12.2-GHz sources towards 400 6.7-GHz methanol maser targets, equating to a detection rate of 46 per cent. Of the 184 12.2-GHz detections, 117 are reported here for the first time. We draw attention to a number of 'special' sources, particularly those with emission at 12.2-GHz stronger than their 6.7-GHz counterpart and conclude that these unusual sources are not associated with a specific evolutionary stage.Comment: accepted to MNRAS 21 Dec 201

A method to reveal workload weak-resilience-signals at a rail control post

Reorganization of a rail control post may affect its ability to cope with unexpected disruptions. The term ‘resilience’, the ability to manage spare adaptive capacity when unexpected events occur, encapsulates this situation. This paper focuses on the workload adaptive capacity through a method for revealing workload weak-resilience-signals (WRS). Three different workload measurements are adapted to identify structural changes in workload. The first, executed cognitive task load, targets system activities. The second, integrated workload scale, is a subjective measure. The last, heart rate variability, identifies physiological arousal because of workload. An experiment is designed to identify the workload change and distribution across group members during disruptions. A newly defined Stretch, the reaction of the system to an external cluster-event, is used to reveal a workload WRS. The method is suitable for real-time usage and provides the means for the rail signaler to influence the system through his subjective workload perception

A Strong Jet Signature in the Late-Time Lightcurve of GW170817

We present new 0.6-10 GHz observations of the binary neutron star merger GW170817 covering the period up to 300 days post-merger, taken with the Karl G. Jansky Very Large Array, the Australia Telescope Compact Array, the Giant Metrewave Radio Telescope and the MeerKAT telescope. We use these data to precisely characterize the decay phase of the late-time radio light curve. We find that the temporal decay is consistent with a power-law slope of t^-2.2, and that the transition between the power-law rise and decay is relatively sharp. Such a slope cannot be produced by a quasi-isotropic (cocoon-dominated) outflow, but is instead the classic signature of a relativistic jet. This provides strong observational evidence that GW170817 produced a successful jet, and directly demonstrates the link between binary neutron star mergers and short-hard GRBs. Using simple analytical arguments, we derive constraints on the geometry and the jet opening angle of GW170817. These results are consistent with those from our companion Very Long Baseline Interferometry (VLBI) paper, reporting superluminal motion in GW170817.Comment: 11 pages, 3 figures, 3 tables. Accepted for publication in ApJ Letter

Surgical site infection after wound closure with staples versus sutures in elective knee and hip arthroplasty:a systematic review and meta-analysis

PURPOSE: This systematic review and meta-analysis aimed to study surgical site infection of wound closure using staples versus sutures in elective knee and hip arthroplasties. METHODS: A systematic literature review was performed to search for randomized controlled trials that compared surgical site infection after wound closure using staples versus sutures in elective knee and hip arthroplasties. The primary outcome was surgical site infection. The risk of bias was assessed with the Cochrane risk of bias assessment tool. The relative risk and 95% confidence interval with a random-effects model were assessed. RESULTS: Eight studies were included in this study, including 2 studies with a low risk of bias, 4 studies having ‘some concerns’, and 2 studies with high risk of bias. Significant difference was not found in the risk of SSI for patients with staples (n = 557) versus sutures (n = 573) (RR: 1.70, 95% CI: 0.94–3.08, I(2) = 16%). The results were similar after excluding the studies with a high risk of bias (RR: 1.67, 95% CI: 0.91–3.07, I(2) = 32%). Analysis of studies with low risk of bias revealed a significantly higher risk of surgical site infection in patients with staples (n = 331) compared to sutures (n = 331) (RR: 2.56, 95% CI: 1.20–5.44, I(2) = 0%). There was no difference between continuous and interrupted sutures (P > 0.05). In hip arthroplasty, stapling carried a significantly higher risk of surgical site infection than suturing (RR: 2.51, 95% CI: 1.15–5.50, I(2) = 0%), but there was no significant difference in knee arthroplasty (RR: 0.87, 95% CI: 0.33–2.25, I(2) = 22%; P > 0.05). CONCLUSIONS: Stapling might carry a higher risk of surgical site infection than suturing in elective knee and hip arthroplasties, especially in hip arthroplasty. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s42836-021-00110-7

12.2-GHz methanol maser MMB follow-up catalogue - II. Longitude range 186 to 330 degrees

We present the second portion of a catalogue of 12.2-GHz methanol masers detected towards 6.7-GHz methanol masers observed in the unbiased Methanol Multibeam (MMB) Survey. Using the Parkes radio telescope we have targeted all 207 6.7-GHz methanol masers in the longitude range 186 to 330 degrees for 12.2-GHz counterparts. We report the detection of 83 12.2-GHz methanol masers, and one additional source which we suspect is thermal emission, equating to a detection rate of 40 per cent. Of the 83 maser detections, 39 are reported here for the first time. We discuss source properties, including variability and highlight a number of unusual sources. We present a list of 45 candidates that are likely to harbor methanol masers in the 107.0-GHz transition.Comment: Accepted MNRAS 19 July 201

Some Secrets of Fluorescent Proteins: Distinct Bleaching in Various Mounting Fluids and Photoactivation of cyan fluorescent proteins at YFP-Excitation

Background&#xd;&#xa;The use of spectrally distinct variants of green fluorescent protein (GFP) such as cyan or yellow mutants (CFP and YFP, respectively) is very common in all different fields of life sciences, e.g. for marking specific proteins or cells or to determine protein interactions. In the latter case, the quantum physical phenomenon of fluorescence resonance energy transfer (FRET) is exploited by specific microscopy techniques to visualize proximity of proteins.&#xd;&#xa;&#xd;&#xa;Methodology/Principal Findings&#xd;&#xa;When we applied a commonly used FRET microscopy technique - the increase in donor (CFP)-fluorescence after bleaching of acceptor fluorophores (YFP), we obtained good signals in live cells, but very weak signals for the same samples after fixation and mounting in commercial microscopy mounting fluids. This observation could be traced back to much faster bleaching of CFP in these mounting media. Strikingly, the opposite effect of the mounting fluid was observed for YFP and also for other proteins such as Cerulean, TFP or Venus. The changes in photostability of CFP and YFP were not caused by the fixation but directly dependent on the mounting fluid. Furthermore we made the interesting observation that the CFP-fluorescence intensity increases by about 10 - 15% after illumination at the YFP-excitation wavelength &#x2013; a phenomenon, which was also observed for Cerulean. This photoactivation of cyan fluorescent proteins at the YFP-excitation can cause false-positive signals in the FRET-microscopy technique that is based on bleaching of a yellow FRET acceptor.&#xd;&#xa;&#xd;&#xa;Conclusions/Significance&#xd;&#xa;Our results show that photostability of fluorescent proteins differs significantly for various media and that CFP bleaches significantly faster in commercial mounting fluids, while the opposite is observed for YFP and some other proteins. Moreover, we show that the FRET microscopy technique that is based on bleaching of the YFP is prone to artifacts due to photoactivation of cyan fluorescent proteins under these conditions

New 9.9-GHz methanol masers

The Australia Telescope Compact Array (ATCA) has been used to make the first extensive search for the class I methanol masers at 9.9 GHz. In total, 48 regions of high-mass star formation were observed. In addition to masers in W33-Met (G12.80-0.19) and G343.12-0.06 (IRAS 16547-4247) which have already been reported in the literature, two new 9.9-GHz masers have been found towards G331.13-0.24 and G19.61-0.23. We have determined absolute positions (accurate to roughly a second of arc) for all the detected masers and suggest that some class I masers may be associated with shocks driven into molecular clouds by expanding HII regions. Our observations also imply that the evolutionary stage of a high-mass star forming region when the class I masers are present can outlast the stage when the class II masers at 6.7 GHz are detectable, and overlaps significantly with the stage when OH masers are active.Comment: accepted for publication in MNRAS, 14 pages, 3 figures, 4 table