Energetics, but not development, is impacted in coral embryos exposed to ocean acidification.

In light of the chronic stress and mass mortality reef-building corals face under climate change, it is critical to understand the processes driving reef persistence and replenishment, including coral reproduction and development. Here, we quantified gene expression and sensitivity to ocean acidification across a set of developmental stages in the rice coral, Montipora capitata. Embryos and swimming larvae were exposed to pH treatments of 7.8 (ambient), 7.6 (low) and 7.3 (extreme low) from fertilization to 9 days post-fertilization. Embryo and larval volume, and stage-specific gene expression were compared between treatments to determine the effects of acidified seawater on early development. Although there was no measurable size differentiation between pH treatments at the fertilized egg and prawn chip (9 h post-fertilization) stages, early gastrulae and larvae raised in reduced pH treatments were significantly smaller than those raised in ambient seawater, suggesting an energetic cost to developing under low pH. However, no differentially expressed genes were found until the swimming larval stage. Notably, gene expression patterns of larvae developing at pH 7.8 and pH 7.3 were more similar than those of larvae developing at pH 7.6. Larvae from pH 7.6 showed upregulation of genes involved in cell division, regulation of transcription, lipid metabolism and response to oxidative stress in comparison to the other two treatments. Although low pH appears to increase energetic demands and trigger oxidative stress in larvae, the developmental process is robust to this at a molecular level, with the swimming larval stage reached in all pH treatments.

Tailoring grating strip widths for optimizing infrared absorption signals of an adsorbed molecular monolayer.

Metal structures with resonances in the mid-infrared spectral range enable an increased sensitivity for detecting molecular vibrational signals. 1D gold strip gratings have already proven potential in surface-enhanced infrared absorption (SEIRA) experiments, as grating resonances and local electric field enhancement can be spectrally tuned by changing the grating period. Here, we identify the grating strip width as another important design parameter, which is investigated for further optimization of molecular absorption signal enhancement in SEIRA experiments. Previous literature used gratings to increase light absorption in relatively thick polymer layers. Here, we demonstrate the capability of gold strip gratings fabricated on a CaF2 substrate to enhance the CH2 vibrational modes of a thiol-based monolayer of MHDA. An optimal choice of the strip width w = 1.33 µm enables a maximum vibrational signal enhancement factor of around 84, when normalized to microscopic GIR measurements of an MHDA monolayer on an extended gold surface. Numerical simulations demonstrate the broadband local field enhancement of gold strip gratings, which are suitable for enhancing multiple vibrational modes in a large hot-spot volume.

The spectral quality of light is a key driver of photosynthesis and photoadaptation in Stylophora pistillata colonies from different depths in the Red Sea.

Depth zonation on coral reefs is largely driven by the amount of downwelling, photosynthetically active radiation (PAR) that is absorbed by the symbiotic algae (zooxanthellae) of corals. The minimum light requirements of zooxanthellae are related to both the total intensity of downwelling PAR and the spectral quality of the light. Here we used Stylophora pistillata colonies collected from shallow (3 m) and deep (40 m) water; colonies were placed in a respirometer under both ambient PAR irradiance and a filter that only transmits blue light. We found that the colonies exhibited a clear difference in their photosynthetic rates when illuminated under PAR and filtered blue light, with higher photosynthetic performance when deep colonies were exposed to blue light compared with full-spectrum PAR for the same light intensity and duration. By contrast, colonies from shallow water showed the opposite trend, with higher photosynthetic performances under full-spectrum PAR than under filtered blue light. These findings are supported by the absorption spectra of corals, with deeper colonies absorbing higher energy wavelengths than the shallow colonies, with different spectral signatures. Our results indicate that S. pistillata colonies are chromatically adapted to their surrounding light environment, with photoacclimation probably occurring via an increase in photosynthetic pigments rather than algal density. The spectral properties of the downwelling light are clearly a crucial component of photoacclimation that should be considered in future transplantation and photoacclimation studies.

Portable infusion pumps in ambulatory cancer chemotherapy.

Fifty-seven adult patients receiving chemotherapy were treated with a total of 133 infusions using portable user-worn infusion pumps, the Autosyringe AS*2F Cormed ML6-4, and two earlier versions of the latter, the Sigmamotor ML6-2 and ML6-3. Ninety-eight infusions were given on an ambulatory basis. Fourteen infusions were given through peripheral venous catheters, 115 through central venous catheters, and four intra-arterially. Of 127 evaluable infusions, 65 were completed within 5% and 87 within 10% of the planned rate; results are similar for both inpatient and outpatient infusions. The Cormed ML6-4 pump was equal to the Autosyringe AS*2F in reliability but superior to the latter in patient preference. There were no instances of dangerously rapid administration of the drug. The only serious catheter complications were a pneumothorax after insertion of a subclavian catheter in one patient and cellulitis in a leukopenic patient with a Broviac catheter. All but three patients preferred outpatient therapy to hospitalization. Outpatient therapy costs about $300 per day less than in-hospital treatment.