Three-dimensional images of choanoflagellate loricae

Choanoflagellates are unicellular filter-feeding protozoa distributed universally in aquatic habitats. Cells are ovoid in shape with a single anterior flagellum encircled by a funnel-shaped collar of microvilli. Movement of the flagellum creates water currents from which food particles are entrapped on the outer surface of the collar and ingested by pseudopodia. One group of marine choanoflagellates has evolved an elaborate basket-like exoskeleton, the lorica, comprising two layers of siliceous costae made up of costal strips. A computer graphic model has been developed for generating three-dimensional images of choanoflagellate loricae based on a universal set of 'rules' derived from electron microscopical observations. This model has proved seminal in understanding how complex costal patterns can be assembled in a single continuous movement. The lorica, which provides a rigid framework around the cell, is multifunctional. It resists the locomotory forces generated by flagellar movement, directs and enhances water flow over the collar and, for planktonic species, contributes towards maintaining cells in suspension. Since the functional morphology of choanoflagellate cells is so effective and has been highly conserved within the group, the ecological and evolutionary radiation of choanoflagellates is almost entirely dependent on the ability of the external coverings, particularly the lorica, to diversify

Optical enhancement strategies on centrifugal microfluidic water sensors for detection of phosphate

Phosphorous is one of the principle elements contributing to eutrophication[1] in coastal, marine and fresh water. This study aims to develop new technologies that can enabled near real-time, rapid, reliable and robust analysis of water nutrient levels, such as phosphate, in water systems. Herein, describes an enhancement study of a previously demonstrated lab-on-a-disc (LOAD) centrifugal microfluidic device for the detection of phosphate in freshwater. The LOAD device utilizes a microfluidic sample processing to enable high precision metering and reagent mixing, followed by colorimetric analysis (at 880 nm) of the resultant complex. A customisable and complementary, in-house analysis system was also developed to enhance user interaction and enable rapid analysis. This analysis system delivers both disc centrifugation and automated colourimetric detection of the LOAD device, with recording of data transmitted via PC interface. The aim of this study is to maintain the same level of sensitivity of the current[2] system with a reduced pathlength. The limit of detection (LOD) and limit of quantification (LOQ) for this new revised system are as follows: The blackened chip obtained the best sensitivity with an LOD and LOQ of 6 and 19 μg L-1 respectively

Template-Directed Ligation of Peptides to Oligonucleotides

Synthetic oligonucleotides and peptides have enjoyed a wide range of applications in both biology and chemistry. As a consequence, oligonucleotide-peptide conjugates have received considerable attention, most notably in the development of antisense constructs with improved pharmacological properties. In addition, oligonucleotide-peptide conjugates have been used as molecular tags, in the assembly of supramolecular arrays and in the construction of encoded combinatorial libraries. To make these chimeric molecules more accessible for a broad range of investigations, we sought to develop a facile method for joining fully deprotected oligonucleotides and peptides through a stable amide bond linkage. Furthermore, we wished to make this ligation reaction addressable, enabling one to direct the ligation of specific oligonucleotide and peptide components.To confer specificity and accelerate the rate of the reaction, the ligation process was designed to be dependent on the presence of a complementary oligonucleotide template

ProtoDESI: First On-Sky Technology Demonstration for the Dark Energy Spectroscopic Instrument

The Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the universe using the baryon acoustic oscillations technique. The spectra of 35 million galaxies and quasars over 14,000 square degrees will be measured during a 5-year survey. A new prime focus corrector for the Mayall telescope at Kitt Peak National Observatory will deliver light to 5,000 individually targeted fiber-fed robotic positioners. The fibers in turn feed ten broadband multi-object spectrographs. We describe the ProtoDESI experiment, that was installed and commissioned on the 4-m Mayall telescope from August 14 to September 30, 2016. ProtoDESI was an on-sky technology demonstration with the goal to reduce technical risks associated with aligning optical fibers with targets using robotic fiber positioners and maintaining the stability required to operate DESI. The ProtoDESI prime focus instrument, consisting of three fiber positioners, illuminated fiducials, and a guide camera, was installed behind the existing Mosaic corrector on the Mayall telescope. A Fiber View Camera was mounted in the Cassegrain cage of the telescope and provided feedback metrology for positioning the fibers. ProtoDESI also provided a platform for early integration of hardware with the DESI Instrument Control System that controls the subsystems, provides communication with the Telescope Control System, and collects instrument telemetry data. Lacking a spectrograph, ProtoDESI monitored the output of the fibers using a Fiber Photometry Camera mounted on the prime focus instrument. ProtoDESI was successful in acquiring targets with the robotically positioned fibers and demonstrated that the DESI guiding requirements can be met.Comment: Accepted versio

The Effect of Iron Limitation on the Transcriptome and Proteome of Pseudomonas fluorescens Pf-5

One of the most important micronutrients for bacterial growth is iron, whose bioavailability in soil is limited. Consequently, rhizospheric bacteria such as Pseudomonas fluorescens employ a range of mechanisms to acquire or compete for iron. We investigated the transcriptomic and proteomic effects of iron limitation on P. fluorescens Pf-5 by employing microarray and iTRAQ techniques, respectively. Analysis of this data revealed that genes encoding functions related to iron homeostasis, including pyoverdine and enantio-pyochelin biosynthesis, a number of TonB-dependent receptor systems, as well as some inner-membrane transporters, were significantly up-regulated in response to iron limitation. Transcription of a ribosomal protein L36-encoding gene was also highly up-regulated during iron limitation. Certain genes or proteins involved in biosynthesis of secondary metabolites such as 2,4-diacetylphloroglucinol (DAPG), orfamide A and pyrrolnitrin, as well as a chitinase, were over-expressed under iron-limited conditions. In contrast, we observed that expression of genes involved in hydrogen cyanide production and flagellar biosynthesis were down-regulated in an iron-depleted culture medium. Phenotypic tests revealed that Pf-5 had reduced swarming motility on semi-solid agar in response to iron limitation. Comparison of the transcriptomic data with the proteomic data suggested that iron acquisition is regulated at both the transcriptional and post-transcriptional levels

Effects of Long-Term Stowage on the Deployment of Bistable Tape Springs

In the context of strain-energy-deployed space structures, material relaxation effects play a significant role in structures that are stowed for long durations, for example, in a space vehicle prior to launch. Here, the deployment of an ultrathin carbon fiber reinforced plastic (CFRP) tape spring is studied, with the aim of understanding how longduration stowage affects its deployment behavior. Analytical modeling and experiments show that the deployment time increases predictably with stowage time and temperature, and analytical predictions are found to compare well with experiments. For cases where stress relaxation is excessive, the structure is shown to lose its ability to deploy autonomously

Systematic Review to Inform a World Health Organization (WHO) Clinical Practice Guideline: Benefits and Harms of Needling Therapies for Chronic Primary Low Back Pain in Adults

PURPOSE Evaluate benefits and harms of needling therapies (NT) for chronic primary low back pain (CPLBP) in adults to inform a World Health Organization (WHO) standard clinical guideline. METHODS Electronic databases were searched for randomized controlled trials (RCTs) assessing NT compared with placebo/sham, usual care, or no intervention (comparing interventions where the attributable effect could be isolated). We conducted meta-analyses where indicated and graded the certainty of evidence. RESULTS We screened 1831 citations and 109 full text RCTs, yeilding 37 RCTs. The certainty of evidence was low or very low across all included outcomes. There was little or no difference between NT and comparisons across most outcomes; there may be some benefits for certain outcomes. Compared with sham, NT improved health-related quality of life (HRQoL) (physical) (2 RCTs; SMD = 0.20, 95%CI 0.07; 0.32) at 6 months. Compared with no intervention, NT reduced pain at 2 weeks (21 RCTs; MD = - 1.21, 95%CI - 1.50; - 0.92) and 3 months (9 RCTs; MD = - 1.56, 95%CI - 2.80; - 0.95); and reduced functional limitations at 2 weeks (19 RCTs; SMD = - 1.39, 95%CI - 2.00; - 0.77) and 3 months (8 RCTs; SMD = - 0.57, 95%CI - 0.92; - 0.22). In older adults, NT reduced functional limitations at 2 weeks (SMD = - 1.10, 95%CI - 1.71; - 0.48) and 3 months (SMD = - 1.04, 95%CI - 1.66; - 0.43). Compared with usual care, NT reduced pain (MD = - 1.35, 95%CI - 1.86; - 0.84) and functional limitations (MD = - 2.55, 95%CI - 3.70; - 1.40) at 3 months. CONCLUSION Based on low to very low certainty evidence, adults with CPLBP experienced some benefits in pain, functioning, or HRQoL with NT; however, evidence showed little to no differences for other outcomes

Systematic Review to Inform a World Health Organization (WHO) Clinical Practice Guideline: Benefits and Harms of Transcutaneous Electrical Nerve Stimulation (TENS) for Chronic Primary Low Back Pain in Adults

PURPOSE: To evaluate benefits and harms of transcutaneous electrical nerve stimulation (TENS) for chronic primary low back pain (CPLBP) in adults to inform a World Health Organization (WHO) standard clinical guideline. METHODS: We searched for randomized controlled trials (RCTs) from various electronic databases from July 1, 2007 to March 9, 2022. Eligible RCTs targeted TENS compared to placebo/sham, usual care, no intervention, or interventions with isolated TENS effects (i.e., combined TENS with treatment B versus treatment B alone) in adults with CPLBP. We extracted outcomes requested by the WHO Guideline Development Group, appraised the risk of bias, conducted meta-analyses where appropriate, and graded the certainty of evidence using GRADE. RESULTS: Seventeen RCTs (adults, n = 1027; adults ≥ 60 years, n = 28) out of 2010 records and 89 full text RCTs screened were included. The evidence suggested that TENS resulted in a marginal reduction in pain compared to sham (9 RCTs) in the immediate term (2 weeks) (mean difference (MD) = -0.90, 95% confidence interval  -1.54 to -0.26), and a reduction in pain catastrophizing in the short term (3 months) with TENS versus no intervention or interventions with TENS specific effects (1 RCT) (MD = -11.20, 95% CI -17.88 to -3.52). For other outcomes, little or no difference was found between TENS and the comparison interventions. The certainty of the evidence for all outcomes was very low. CONCLUSIONS: Based on very low certainty evidence, TENS resulted in brief and marginal reductions in pain (not deemed clinically important) and a short-term reduction in pain catastrophizing in adults with CPLBP, while little to no differences were found for other outcomes

At Home in the Neolithic : Understanding Diversity in Neolithic Houses and Households

In the Editorial for the special edition on Neolithic Housesholds, we introduce the history of house and household studies in European Neolithic Archaeology and outline the papers in this collection

Overview of the Dark Energy Spectroscopic Instrument

The Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the Universe using the Baryon Acoustic Oscillation technique. The spectra of 35 million galaxies and quasars over 14000 square degrees will be measured during the life of the experiment. A new prime focus corrector for the KPNO Mayall telescope will deliver light to 5000 fiber optic positioners. The fibers in turn feed ten broad-band spectrographs. We present an overview of the instrumentation, the main technical requirements and challenges, and the current status of the project.Comment: 11 pages, 4 figure