PSR1 is a global transcriptional regulator of phosphorus deficiency responses and carbon storage metabolism in Chlamydomonas reinhardtii.

Many eukaryotic microalgae modify their metabolism in response to nutrient stresses such as phosphorus (P) starvation, which substantially induces storage metabolite biosynthesis, but the genetic mechanisms regulating this response are poorly understood. Here, we show that P starvation-induced lipid and starch accumulation is inhibited in a Chlamydomonas reinhardtii mutant lacking the transcription factor Pi Starvation Response1 (PSR1). Transcriptomic analysis identified specific metabolism transcripts that are induced by P starvation but misregulated in the psr1 mutant. These include transcripts for starch and triacylglycerol synthesis but also transcripts for photosynthesis-, redox-, and stress signaling-related proteins. To further examine the role of PSR1 in regulating lipid and starch metabolism, PSR1 complementation lines in the psr1 strain and PSR1 overexpression lines in a cell wall-deficient strain were generated. PSR1 expression in the psr1 lines was shown to be functional due to rescue of the psr1 phenotype. PSR1 overexpression lines exhibited increased starch content and number of starch granules per cell, which correlated with a higher expression of specific starch metabolism genes but reduced neutral lipid content. Furthermore, this phenotype was consistent in the presence and absence of acetate. Together, these results identify a key transcriptional regulator in global metabolism and demonstrate transcriptional engineering in microalgae to modulate starch biosynthesis

Near Infrared Hydrogen Emission Line Ratios as Diagnostics of the Broad Emission Line Region

Broad emission line flux ratios are a powerful diagnostic of the physical conditions of the broad-line region gas in Active Galactic Nuclei. With recent advances in infrared spectroscopy, previously unstudied emission lines provide a new means to investigate the physical nature of the BELR gas. The hydrogen emission lines are particularly sensitive to the upper limits of both the radius from the central ionising source and the number density of the gas. Using an existing subset of near-infrared quasar spectra from the Glikman et al. (2006) sample [1] together with Cloudy photoionization simulations, we confirm the Locally Optimally emitting Cloud (LOC) model\u27s ability to reproduce observed emission line flux ratios. The model is then used to constrain physical conditions for individual sources. The photoionization models show that high number density, low incident flux gas is required to reproduce observed near-infrared hydrogen emission line ratios. We also find that comparison to individual sources, rather than composites, is vital

Adenoidectomy for otitis media with effusion (OME) in children

BACKGROUND: Otitis media with effusion (OME) is an accumulation of fluid in the middle ear cavity, common amongst young children. The fluid may cause hearing loss. When persistent, it may lead to developmental delay, social difficulty and poor quality of life. Management of OME includes watchful waiting, autoinflation, medical and surgical treatment. Adenoidectomy has often been used as a potential treatment for this condition. OBJECTIVES: To assess the benefits and harms of adenoidectomy, either alone or in combination with ventilation tubes (grommets), for OME in children. SEARCH METHODS: The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 20 January 2023. SELECTION CRITERIA: Randomised controlled trials and quasi-randomised trials in children aged 6 months to 12 years with unilateral or bilateral OME. We included studies that compared adenoidectomy (alone, or in combination with ventilation tubes) with either no treatment or non-surgical treatment. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Primary outcomes (determined following a multi-stakeholder prioritisation exercise): 1) hearing, 2) otitis media-specific quality of life, 3) haemorrhage. SECONDARY OUTCOMES: 1) persistence of OME, 2) adverse effects, 3) receptive language skills, 4) speech development, 5) cognitive development, 6) psychosocial skills, 7) listening skills, 8) generic health-related quality of life, 9) parental stress, 10) vestibular function, 11) episodes of acute otitis media. We used GRADE to assess the certainty of evidence for each outcome. Although we included all measures of hearing assessment, the proportion of children who returned to normal hearing was our preferred method to assess hearing, due to challenges in interpreting the results of mean hearing thresholds. MAIN RESULTS: We included 10 studies (1785 children). Many of the studies used concomitant interventions for all participants, including insertion of ventilation tubes or myringotomy. All included studies had at least some concerns regarding the risk of bias. We report results for our main outcome measures at the longest available follow-up. We did not identify any data on disease-specific quality of life for any of the comparisons. Further details of additional outcomes and time points are reported in the review. 1) Adenoidectomy (with or without myringotomy) versus no treatment/watchful waiting (three studies) After 12 months there was little difference in the proportion of children whose hearing had returned to normal, but the evidence was very uncertain (adenoidectomy 68%, no treatment 70%; risk ratio (RR) 0.97, 95% confidence interval (CI) 0.65 to 1.46; number needed to treat to benefit (NNTB) 50; 1 study, 42 participants). There is a risk of haemorrhage from adenoidectomy, but the absolute risk appears small (1/251 receiving adenoidectomy compared to 0/229, Peto odds ratio (OR) 6.77, 95% CI 0.13 to 342.54; 1 study, 480 participants; moderate certainty evidence). The risk of persistent OME may be slightly lower after two years in those receiving adenoidectomy (65% versus 73%), but again the difference was small (RR 0.90, 95% CI 0.81 to 1.00; NNTB 13; 3 studies, 354 participants; very low-certainty evidence). 2) Adenoidectomy (with or without myringotomy) versus non-surgical treatment No studies were identified for this comparison. 3) Adenoidectomy and bilateral ventilation tubes versus bilateral ventilation tubes (four studies) There was a slight increase in the proportion of ears with a return to normal hearing after six to nine months (57% adenoidectomy versus 42% without, RR 1.36, 95% CI 0.98 to 1.89; NNTB 7; 1 study, 127 participants (213 ears); very low-certainty evidence). Adenoidectomy may give an increased risk of haemorrhage, but the absolute risk appears small, and the evidence was uncertain (2/416 with adenoidectomy compared to 0/375 in the control group, Peto OR 6.68, 95% CI 0.42 to 107.18; 2 studies, 791 participants). The risk of persistent OME was similar for both groups (82% adenoidectomy and ventilation tubes compared to 85% ventilation tubes alone, RR 0.96, 95% CI 0.86 to 1.07; very low-certainty evidence). 4) Adenoidectomy and unilateral ventilation tube versus unilateral ventilation tube (two studies) Slightly more children returned to normal hearing after adenoidectomy, but the confidence intervals were wide (57% versus 46%, RR 1.24, 95% CI 0.79 to 1.96; NNTB 9; 1 study, 72 participants; very low-certainty evidence). Fewer children may have persistent OME after 12 months, but again the confidence intervals were wide (27.2% compared to 40.5%, RR 0.67, 95% CI 0.35 to 1.29; NNTB 8; 1 study, 74 participants). We did not identify any data on haemorrhage. 5) Adenoidectomy and ventilation tubes versus no treatment/watchful waiting (two studies) We did not identify data on the proportion of children who returned to normal hearing. However, after two years, the mean difference in hearing threshold for those allocated to adenoidectomy was -3.40 dB (95% CI -5.54 to -1.26; 1 study, 211 participants; very low-certainty evidence). There may be a small reduction in the proportion of children with persistent OME after two years, but the evidence was very uncertain (82% compared to 90%, RR 0.91, 95% CI 0.82 to 1.01; NNTB 13; 1 study, 232 participants). We noted that many children in the watchful waiting group had also received surgery by this time point. 6) Adenoidectomy and ventilation tubes versus non-surgical treatment No studies were identified for this comparison. AUTHORS' CONCLUSIONS: When assessed with the GRADE approach, the evidence for adenoidectomy in children with OME is very uncertain. Adenoidectomy may reduce the persistence of OME, although evidence about the effect of this on hearing is unclear. For patients and carers, a return to normal hearing is likely to be important, but few studies measured this outcome. We did not identify any evidence on disease-specific quality of life. There were few data on adverse effects, in particular postoperative bleeding. The risk of haemorrhage appears to be small, but should be considered when choosing a treatment strategy for children with OME. Future studies should aim to determine which children are most likely to benefit from treatment, rather than offering interventions to all children

The HST Survey of BL Lac Objects: Gravitational Lens Candidates and Other Unusual Sources

We present HST observations of seven unusual objects from the HST ``snapshot survey'' of BL Lac objects, of which four are gravitational lens candidates. In three cases a double point sources is observed: 0033+595, with 1.58 arcsec separation, and 0502+675 and 1440+122, each with $\sim 0.3$ arcsec separation. The last two also show one or more galaxies, which could be either host or lensing galaxies. If any are confirmed as lenses, these BL Lac objects are excellent candidates for measuring H$_0$ via gravitational time delay because of their characteristic rapid, high amplitude variability. An additional advantage is that, like other blazars, they are likely superluminal radio sources, in which case the source plane is mapped out over a period of years, providing strong additional constraints on the lensing mass distribution. The fourth gravitational lens candidate is 1517+656, which is surrounded by three arclets forming an almost perfect ring of radius 2.4 arcsec. If this is indeed an Einstein ring, it is most likely a background source gravitationally lensed by the BL Lac object host galaxy and possibly a surrounding group or cluster. In the extreme case that all four candidates are true lenses, the derived frequency of gravitational lensing in this BL Lac sample would be an order of magnitude higher than in comparable quasar samples. We also report on three other remarkable BL Lac objects: 0138-097, which is surrounded by a large number of close companion galaxies; 0806+524, whose host galaxy contains an uncommon arc-like structure; and 1959+650, which is hosted by a gas rich elliptical galaxy with a prominent dust lane of $\sim 5\times 10^5 M_\odot$.Comment: 29 pages in total, 12 figure

Biomechanical, biochemical, and morphological mechanisms of heat shock-mediated germination in Carica papaya seed.

Carica papaya (papaya) seed germinate readily fresh from the fruit, but desiccation induces a dormant state. Dormancy can be released by exposure of the hydrated seed to a pulse of elevated temperature, typical of that encountered in its tropical habitat. Carica papaya is one of only a few species known to germinate in response to heat shock (HS) and we know little of the mechanisms that control germination in tropical ecosystems. Here we investigate the mechanisms that mediate HS-induced stimulation of germination in pre-dried and re-imbibed papaya seed. Exogenous gibberellic acid (GA3 ≥250 µM) overcame the requirement for HS to initiate germination. However, HS did not sensitise seeds to GA3, indicative that it may act independently of GA biosynthesis. Seed coat removal also overcame desiccation-imposed dormancy, indicative that resistance to radicle emergence is coat-imposed. Morphological and biomechanical studies identified that neither desiccation nor HS alter the physical structure or the mechanical strength of the seed coat. However, cycloheximide prevented both seed coat weakening and germination, implicating a requirement for de novo protein synthesis in both processes. The germination antagonist abscisic acid prevented radicle emergence but had no effect on papaya seed coat weakening. Desiccation therefore appears to reduce embryo growth potential, which is reversed by HS, without physically altering the mechanical properties of the seed coat. The ability to germinate in response to a HS may confer a competitive advantage to C. papaya, an opportunistic pioneer species, through detection of canopy removal in tropical forests

Chlorhexidine hexametaphosphate as a wound care material coating: antimicrobial efficacy, toxicity and effect on healing.

AIM: In this study, chlorhexidine hexametaphosphate (CHX-HMP) is investigated as a persistent antimicrobial coating for wound care materials. MATERIALS & METHODS: CHX-HMP was used as a wound care material coating and compared with chlorhexidine digluconate materials with respect to antimicrobial efficacy, toxicity and wound closure. RESULTS: Antimicrobial efficacy at day 1, 3 and 7 was observed with experimental and commercial materials. CHX-HMP coated materials had less toxic effect on human placental cells than commercial chlorhexidine dressings. CHX-HMP in pluronic gel did not delay healing but reduced wound colonization by E. faecalis. CONCLUSION: CHX-HMP could become a useful component of wound care materials with sustained antimicrobial efficacy, lower toxicity than chlorhexidine digluconate materials, and reduction in wound colonization without affecting closure

The Murchison Widefield Array: Design Overview

The Murchison Widefield Array (MWA) is a dipole-based aperture array synthesis telescope designed to operate in the 80-300 MHz frequency range. It is capable of a wide range of science investigations, but is initially focused on three key science projects. These are detection and characterization of 3-dimensional brightness temperature fluctuations in the 21cm line of neutral hydrogen during the Epoch of Reionization (EoR) at redshifts from 6 to 10, solar imaging and remote sensing of the inner heliosphere via propagation effects on signals from distant background sources,and high-sensitivity exploration of the variable radio sky. The array design features 8192 dual-polarization broad-band active dipoles, arranged into 512 tiles comprising 16 dipoles each. The tiles are quasi-randomly distributed over an aperture 1.5km in diameter, with a small number of outliers extending to 3km. All tile-tile baselines are correlated in custom FPGA-based hardware, yielding a Nyquist-sampled instantaneous monochromatic uv coverage and unprecedented point spread function (PSF) quality. The correlated data are calibrated in real time using novel position-dependent self-calibration algorithms. The array is located in the Murchison region of outback Western Australia. This region is characterized by extremely low population density and a superbly radio-quiet environment,allowing full exploitation of the instrumental capabilities.Comment: 9 pages, 5 figures, 1 table. Accepted for publication in Proceedings of the IEE

The HIPASS Catalogue - II. Completeness, Reliability, and Parameter Accuracy

The HI Parkes All Sky Survey (HIPASS) is a blind extragalactic HI 21-cm emission line survey covering the whole southern sky from declination -90 to +25. The HIPASS catalogue (HICAT), containing 4315 HI-selected galaxies from the region south of declination +2, is presented in Meyer et al. (2004a, Paper I). This paper describes in detail the completeness and reliability of HICAT, which are calculated from the recovery rate of synthetic sources and follow-up observations, respectively. HICAT is found to be 99 per cent complete at a peak flux of 84 mJy and an integrated flux of 9.4 Jy km/s. The overall reliability is 95 per cent, but rises to 99 per cent for sources with peak fluxes >58 mJy or integrated flux > 8.2 Jy km/s. Expressions are derived for the uncertainties on the most important HICAT parameters: peak flux, integrated flux, velocity width, and recessional velocity. The errors on HICAT parameters are dominated by the noise in the HIPASS data, rather than by the parametrization procedure.Comment: Accepted for publication in MNRAS. 12 pages, 11 figures. Paper with higher resolution figures can be downloaded from http://hipass.aus-vo.or

Causes, patterns and severity of androgen excess in 487 consecutively recruited pre- and post-pubertal children

Objective Androgen excess in childhood is a common presentation and may signify sinister underlying pathology. Data describing its patterns and severity are scarce, limiting the information available for clinical decision processes. Here, we examined the differential diagnostic value of serum DHEAS, androstenedione (A4) and testosterone in childhood androgen excess. Design Retrospective review of all children undergoing serum androgen measurement at a single center over 5 years. Methods Serum A4 and testosterone were measured by tandem mass spectrometry and DHEAS by immunoassay. Patients with at least one increased androgen underwent phenotyping by clinical notes review. Results In 487 children with simultaneous DHEAS, A4 and testosterone measurements, we identified 199 with androgen excess (140 pre- and 59 post-pubertal). Premature adrenarche (PA) was the most common pre-pubertal diagnosis (61%), characterized by DHEAS excess in 85%, while A4 and testosterone were only increased in 26 and 9% respectively. PCOS was diagnosed in 40% of post-pubertal subjects, presenting equally frequent with isolated excess of DHEAS (29%) or testosterone (25%) or increases in both A4 and testosterone (25%). CAH patients (6%) predominantly had A4 excess (86%); testosterone and DHEAS were increased in 50 and 33% respectively. Concentrations increased above the two-fold upper limit of normal were mostly observed in PA for serum DHEAS (&gt;20-fold in the single case of adrenocortical carcinoma) and in CAH for serum androstenedione. Conclusions Patterns and severity of childhood androgen excess provide pointers to the underlying diagnosis and can be used to guide further investigations.</p