PHOTOADAPTIVE RESPONSES IN THE TROPICAL BROWN SEAWEED, LOBOPHORA VARIEGATA (LAMOUR) WOMERS

A study was undertaken to determine if natural growth irradiance regimes influence the pigment content and/or photosynthesis-irradiance relationships of the tropical brown seaweed, Lobophora variegata. Pigment analyses were performed on samples collected from a series of depths between 9 and 49m. Chlorophyll a, chlorophyll c, and fucoxanthin were constant on a thallus weight basis, but showed small decreases when expressed in terms of thallus area. The beta-carotene content of L. variegata was much greater in shallow than in deep-water samples regardless of the pigment units employed. Experimental reduction of the light regime of the shallow population, produced a significant decrease in beta-carotene content within 2 days. In 4 days, beta-carotene had decreased by 55% on a thallus weight basis, while no significant changes were found in any of the other three pigments. Photosynthesis-irradiance (P-I) relationships were determined in situ for Lobophora variegata populations from a series of depths between 4.6 and 36.6m. Determinations were made for each population at its native depth, as well as at the spectral regimes of several other depths. The shallowest population examined was found to have a substantially higher rate of light saturated photosynthesis (P(,max)) compared with populations from greater depths. Further reductions of P(,max) with depth were evident on a thallus area basis, but not on a thallus weight basis. The efficiency of low-light photosynthesis, indicated by the initial slope (alpha) of the P-I curve, was found to increase with depth regardless of the depth from which the L. variegata samples were collected

Tracking environmental trends in the Great Bay Estuarine System through comparisons of historical and present-day green and red algal community structure and nutrient content

Monitoring macroalgae populations is an effective means of detecting long term water quality changes in estuarine systems. To investigate the environmental status of New Hampshire’s Great Bay National Estuarine Research Reserve, this study assessed the abundance/distribution of macrophytes, particularly Gracilaria and Ulva species, relative to eutrophication patterns; compared historical (1970s-1990s) and current algal biomass/cover at several sites; and compared Ulva and Gracilaria tissue N/P content to ambient and historical levels. Ulva and Gracilaria biomass/cover have increased significantly at several sites. Cover by Ulva species, at seasonal maxima, was over 90 times the value recorded in the 1970s at Lubberland Creek, and exceeded 50% at all sites in the upper estuary. Gracilaria cover was greater than 25% at Depot Road in the upper estuary, whereas the historical measure was 1%. Sequencing of ITS2, rbcL and CO1 revealed the presence of previously undetected Ulva and Gracilaria species, including Gracilaria vermiculophylla (Ohmi) Papenfuss, an invasive species of Asian origin. Gracilaria vermiculophylla has exceeded G. tikvahiae as the dominant Gracilaria species in Great Bay. Historical voucher specimen screening suggests G. vermiculophylla was introduced as recently as 2003. Nitrogen and phosphorus levels are elevated in the estuary. We should expect continued seasonal nuisance algal blooms

Southern expansion of the brown alga Colpomenia peregrina Sauvageau (Scytosiphonales) in the Northwest Atlantic Ocean

Blackler first recorded Colpomenia peregrina in the Northwest Atlantic based on collections from Nova Scotia, Canada. Five decades later we found large quantities of C. peregrina in Maine, USA, even though it was absent during earlier floristic studies in this region. Thus, C. peregrina has undergone a rapid southern expansion along the Northwest Atlantic coast. While the causes of such an expansion are unknown, it could have a major effect on both shellfish cultivation and native seaweeds within New England because of competitive interactions and increased drag

New England Seaweed Culture Handbook

A new 92-page handbook published by Connecticut Sea Grant provides instruction on nursery culture for four economically and ecologically valuable seaweeds. The volume builds on decades of research on the physiological and culture techniques led by Dr. Charles Yarish at UConn and Dr. Christopher Neefus, U. of New Hampshire

Simple Guide to Using Generative Artificial Intelligence Writing Tools in Research & Scholarship at UNH

While Artificial Intelligence (AI) technologies have existed for years, the recent arrival of widespread generative AI writing tools such as ChatGPT has provoked varied reactions in the scholarly community worldwide. Undoubtedly easy access to such tools may help to level the scholarly playing field for certain groups, particularly those with limited writing skills or proficiency with English as the primary language for written and oral communication of research and scholarship. There are, however, concerns about these tools, including, but not limited to, the accuracy, consistency, and bias of the information generated, appropriate acknowledgement of source material, and the tools’ lack of ability to reason or to understand meaning when generating output. This simple guide was developed to assist researchers and trainees to understand the fundamental issues with these technologies regarding research integrity

Effect of Deutetrabenazine on Chorea Among Patients With Huntington Disease A Randomized Clinical Trial

Importance Deutetrabenazine is a novel molecule containing deuterium, which attenuates CYP2D6 metabolism and increases active metabolite half-lives and may therefore lead to stable systemic exposure while preserving key pharmacological activity. Objective To evaluate efficacy and safety of deutetrabenazine treatment to control chorea associated with Huntington disease. Design, Setting, and Participants Ninety ambulatory adults diagnosed with manifest Huntington disease and a baseline total maximal chorea score of 8 or higher (range, 0-28; lower score indicates less chorea) were enrolled from August 2013 to August 2014 and randomized to receive deutetrabenazine (n = 45) or placebo (n = 45) in a double-blind fashion at 34 Huntington Study Group sites. Interventions Deutetrabenazine or placebo was titrated to optimal dose level over 8 weeks and maintained for 4 weeks, followed by a 1-week washout. Main Outcomes and Measures Primary end point was the total maximal chorea score change from baseline (the average of values from the screening and day-0 visits) to maintenance therapy (the average of values from the week 9 and 12 visits) obtained by in-person visits. This study was designed to detect a 2.7-unit treatment difference in scores. The secondary end points, assessed hierarchically, were the proportion of patients who achieved treatment success on the Patient Global Impression of Change (PGIC) and on the Clinical Global Impression of Change (CGIC), the change in 36-Item Short Form– physical functioning subscale score (SF-36), and the change in the Berg Balance Test. Results Ninety patients with Huntington disease (mean age, 53.7 years; 40 women [44.4%]) were enrolled. In the deutetrabenazine group, the mean total maximal chorea scores improved from 12.1 (95% CI, 11.2-12.9) to 7.7 (95% CI, 6.5-8.9), whereas in the placebo group, scores improved from 13.2 (95% CI, 12.2-14.3) to 11.3 (95% CI, 10.0-12.5); the mean between-group difference was –2.5 units (95% CI, –3.7 to –1.3) (P < .001). Treatment success, as measured by the PGIC, occurred in 23 patients (51%) in the deutetrabenazine group vs 9 (20%) in the placebo group (P = .002). As measured by the CGIC, treatment success occurred in 19 patients (42%) in the deutetrabenazine group vs 6 (13%) in the placebo group (P = .002). In the deutetrabenazine group, the mean SF-36 physical functioning subscale scores decreased from 47.5 (95% CI, 44.3-50.8) to 47.4 (44.3-50.5), whereas in the placebo group, scores decreased from 43.2 (95% CI, 40.2-46.3) to 39.9 (95% CI, 36.2-43.6), for a treatment benefit of 4.3 (95% CI, 0.4 to 8.3) (P = .03). There was no difference between groups (mean difference of 1.0 unit; 95% CI, –0.3 to 2.3; P = .14), for improvement in the Berg Balance Test, which improved by 2.2 units (95% CI, 1.3-3.1) in the deutetrabenazine group and by 1.3 units (95% CI, 0.4-2.2) in the placebo group. Adverse event rates were similar for deutetrabenazine and placebo, including depression, anxiety, and akathisia. Conclusions and Relevance Among patients with chorea associated with Huntington disease, the use of deutetrabenazine compared with placebo resulted in improved motor signs at 12 weeks. Further research is needed to assess the clinical importance of the effect size and to determine longer-term efficacy and safety

Lectotypification of Porphyra elongata Kylin (Bangiales, Rhodophyta) and proposed synonymy of Porphyra rosengurttii Coll et Cox

In 1905 Kylin collected a species of Porphyra from the west coast of Sweden, which he described as P. elongata (Aresch.) Kylin. However, P. laciniata var. elongata Aresch., the intended basionym, was never validly published so that the name P. elongata must be attributed directly to Kylin. Sequence data of the rbcL plastid gene obtained from Kylin\u27s original material of R elongata differed by only a single nucleotide transition-from the rbcL sequences for the holotype and isotype of P. rosengurttii Coll et Cox. In this paper, we lectotypify P. elongata and propose A rosengurttii as a synonym

The effects of short- and long-term freezing on Porphyra umbilicalis Kützing (Bangiales, Rhodophyta) blade viability

Seaweeds inhabiting the upper intertidal zone are subjected to temperature, light, and water stresses and vertical distribution has been linked to environmental tolerance. Previous studies have also attributed successful recovery from freezing stress in intertidal seaweeds to desiccation tolerance. Porphyra umbilicalis Kützing is an aseasonal red alga inhabiting the mid to upper intertidal zone in temperate and subarctic regions of the North Atlantic. It is a member of the economically important group of foliose Bangiales, and has been documented to only reproduce asexually via neutral spores in the Northwest Atlantic. The goal of this study was to assess the effects of freezing on the viability of small blades of P. umbilicalis. Cultured blades of P. umbilicalis (4.8 ± 0.22 mg) were air dried to 5% or 30% absolute water content (AWC) and frozen for 1, 3, 6, or 12 months at − 80 °C or − 20 °C. Following freezing, blades were rehydrated and the growth rate of each blade was measured weekly for 4 weeks. Photosynthetic efficiency of photosystem II (Fv/Fm) was assessed for each blade 3 h and 4 weeks post-rehydration. Overall, there was 100% blade survival and all blades continued to grow after rehydration. Although the conditions under which the blades were frozen did have statistically significant effects on post-rehydration growth rate and Fv/Fm, in general the differences were quite small. Post-rehydration growth rates ranged from 7.06 to 8.03 ± 0.16% day− 1. AWC had an effect on post-rehydration growth rates for blades frozen at − 80 °C, but not blades frozen at − 20 °C. The length of freezing had a somewhat greater effect on blades with 5% AWC than blades with 30% AWC. Growth rates peaked two weeks post-rehydration followed by a small decline in weeks 3 and 4. Fv/Fm values following freezing were generally similar to those recorded in previous studies on non-frozen blades; however, blades frozen for 6 months performed better than blades frozen for 12 months. Overall, these results indicate that short- and long-term freezing have little physiological effect on blades of P. umbilicalis. Therefore, freezing may be a viable method for preservation of P. umbilicalis for aquaculture

Effects of temperature, light level, and photoperiod on the physiology of Porphyra umbilicalis Kützing from the Northwest Atlantic, a candidate for aquaculture

Seaweed aquaculture in the Northwest Atlantic has been steadily increasing with five commercial kelp farms already established. Currently, kelp production is limited to winter and spring, and new seaweed crops need to be developed in order to supplement seasonal kelp production. Porphyra umbilicalis is a member of the most economically valuable group of seaweeds known by the Japanese name nori. It is an ideal candidate for aquaculture since it exhibits short production cycles, rapid growth, high nutrient uptake rates, and high pigment and protein content. Further, sexual reproduction appears to be absent in populations in the Northwest Atlantic, which considerably simplifies the production of seed stock. The goal of this study was to determine the conditions that optimize growth, photosynthetic efficiency of photosystem II (Fv/Fm), and pigment and protein content of P. umbilicalis. Cultured blades were grown under a matrix of temperatures (10, 15, and 20 °C), light levels (30, 60, 110, and 250 μmol photons m−2 s−1), and photoperiods (8:16, 12:12, and 16:8 light/dark) in a factorial design for 4 weeks. Growth rates were highest (\u3e9 % day−1) in blades grown between 10 and 15 °C, with light levels ≥110 μmol photons m−2 s−1 and ≥12 h of light in the day. Fv/Fm was significantly affected by photoperiod with this effect dependent on light level; the overall range of Fv/Fm values was small. Here, we report detailed information on the growth rate, Fv/Fm,, and pigment and protein content of P. umbilicalis grown under 36 treatment combinations. These results provide physiological information on P. umbilicalis from the Northwest Atlantic that will aid in the development of P. umbilicalis aquaculture on a commercial scale

Effects of temperature, light level, photoperiod, and ammonium concentration on Pyropia leucosticta (Bangiales, Rhodophyta) from the Northwest Atlantic

Seaweed aquaculture in the Northwest Atlantic is a growing industry that is currently based on winter-spring kelp production. Aquaculture of Pyropia leucosticta, a species of economically valuable nori, could provide a spring-summer crop and diversify the industry. The objectives of this study were to determine the optimum conditions for the production of the foliose blade phase and the conditions for advancement from the microscopic conchocelis to the foliose blade phase of P. leucosticta. Foliose blades were grown under a matrix of temperatures (10, 15, and 20 °C), photoperiods (8:16, 12:12, and 16:8 L:D), and light levels (30, 60, 110, and 250 μmol photons m−2 s−1) for a period of 1 month. Free-living conchocelis was grown under a matrix of temperatures (10, 15, and 20 °C), photoperiods (8:16, 12:12, and 16:8 L:D), and ammonium concentrations (20 and 500 μM) for 8–12 weeks. Blades grew optimally at 10 to 15 °C, ≥110 μmol photons m−2 s−1 and ≥12 h of light in the day, with growth rates of over 18 % day−1 recorded. Phycobilin content of blades significantly decreased with increasing day length, while protein content significantly decreased with increasing light level. Conchospore release and germination was observed after approximately 40 days under all tested photoperiods, temperatures, and ammonium concentrations and none of these treatments significantly affected the time until germination. Overall, this study provides important background information required for the establishment of Pyropia leucosticta aquaculture in the Northwest Atlantic