This work supports previous studies in the Great Barrier Reef lagoon that show the new nitrogen (N) load introduced by Trichodesmium is similar to or greater than that from riverine discharges. However, the current management programs aimed at improving the chronic eutrophic state of the GBR ignore the N load from Trichodesmium. These programs also ignore the evidence that Trichodesmium blooms could promote the bioavailability of heavy metals and be a source of toxins in the ciguatera food chain. Further work is urgently required to better quantify the potential impacts of Trichodesmium and develop management plans to reduce those impacts. A simple algorithm that uses MODIS imagery is developed for not only monitoring the spatial extent of Trichodesmium blooms but also for quantifying the concentration of those blooms. The algorithm is based on the readily available MODIS L2 data. A management plan that includes the harvesting of Trichodesmium is outlined.

Chronic short sleep (CSS), common in modern society, results in degeneration of Locus Coeruleus neuron (LCn). Recently we have identified increased concentrations of phosphorylated microtubule associated protein tau (p-tau). P-tau is implicated in degeneration of neurons in several conditions including Alzheimer’s and Epilepsy. Here, we tested the hypothesis that tau contributes to the CSS-induced degeneration of LCn. We tested two conditions of tau knock down: transgenic knock out of tau protein and SiRNA knock down of tau protein via local injection. Tau -/- and wild type (WT) controls were randomized to CSS or Rested conditions. Following CSS, mice were perfused, and brains prepared for immunohistochemistry. Labeled LCn were stereotactically counted. In a second group of WT mice, mice were injected bilaterally into the LC nuclei with wither tau SiRNA or control (GFP) SiRNA. As above brains were procured for LCn counts. LCn were immunolabeled with anti-tyrosine hydroxylase (TH). Sections were mounted, dried, and counter-stained with Giemsa and confirmed to span rostral-caudal nucleus for each mouse. Neuronal counts were estimated using an optical fractionator minimally-biased approach. While WT mice exposed to CSS produced the expected reduction in LCn counts by stereology (Bonferroni corrected t=3.7, p<0.01), Tau -/- mice conferred resistance to CSS LCn degeneration (t=0.0, N.S.). WT mice treated with tau SiRNA and exposed to CSS maintained normal LCn counts, whereas mice injected with GFP SiRNA showed significantly lower LCn counts (t=3.9, p<0.01), consistent with counts in WT mice exposed to CSS. These data support a role for tau in the CSS degeneration of LCn. NIH grants R01 HL123331, HL 124576, and AG054104 to S.V.

Comment to: Furnas, M., B. Schaffelke, and A.D. McKinnon. 2014. Selective Evidence of Eutrophication in the Great Barrier Reef: Comment on Bell et al. (2014). AMBIO. doi: 10.1007/s13280-013-0471-x. Furnas et al. (2014) suggest that our conclusions are based upon limited sampling programs. However, we note that our principal conclusions, namely, (i) that hard coral cover in the Great Barrier Reef (GBR) has reduced by >70 % over the past century and (ii) that most GBR regions are characterized by Chl a values exceeding the defined chronic-eutrophic state (i.e., >0.2 mg m−3), are based on the extensive AIMS assembled data sets (e.g., see Fig. 3 in Bell et al. 2014). Furnas et al. note that the ocean color data presented in Figs. 4 and 5, and in particular the data in the near-shore regions, do not represent accurate levels of Chl a. We generally agree with this assessment but note that we have not used these data in deriving the Eutrophication Threshold Model (ETM). We note that offshore CZCS data sets were calibrated against field data from the late 1970s and early 1980s, and these calibrated data sets were used to demonstrate that elevated Chl a values occurred in the central and outer GBR lagoon and in remote GBR regions (e.g., see Bell and Gabric 1990; Gabric et al. 1990). The CZCS data also show that elevated phytoplankton productivity occurs “downstream” of reef complexes; this information can be used to assess the importance of N-fixation. Figures 4 and 5 are given in the Review paper (Bell et al. 2014) to illustrate these points and to show that more than three decades ago enough information was available for one to recognize the synoptic-scale chronic-eutrophic state of the GBR; this information was largely ignored by the marine-science community. Furnas et al. note that some GBR regions characterized by annual mean Chl a > 0.3 mg m−3 have healthy reefs and hence the setting of the trigger-value range of 0.40–0.45 mg m−3. However, we note that many unhealthy reefs exist in regions where the annual mean Chl a is <0.3 mg m−3. For example, the Lizard Is region has an annual mean Chl a value of ~0.25 mg m−3 but has a median coral cover of 10–20%; far below that expected for a healthy reef (AIMS 2012). We note that various factors need to be considered when defining trigger values. In particular, the observation that COTS larvae and coral skeletal diseases (CSDs) will probably proliferate in waters characterized by Chl a < 0.3 mg m−3 suggests that lower trigger values need to be set. We note that the recommended Chl a values for the outer Florida Keys lie essentially within the lower ETC-Chl a range i.e., 0.2–0.3 mg m−3 (McGee 2010). Furnas et al. state there is no evidence of increases in the fertility of the GBR lagoon. This comment ignores the results from the Low Isles studies which suggest that there have been significant increases in various phytoplankton populations since 1928–1929 (Bell and Elmetri 1995). We support the inference that the Low Isles studies should have been extended over a number of years to better validate the data; the original plan was to conduct a multi-year monitoring program but funds initially approved by GBRMPA were cut after the first year. Furnas et al. note there is no evidence of increased Trichodesmium populations in the GBR. This observation ignores the work that suggests that Trichodesmium populations have increased significantly in the Low Isles region and that Trichodesmium growth is far more prolific in the P-PO4 rich GBR regions (Bell and Elmetri 1995; Bell et al. 1999). Furnas et al. state that it is very unlikely that nutrients from sewage treatment plants (STPs) near Brisbane affect water quality in the GBR as there is a general southward flow through the southern GBR reef matrix, and the East Australian Current (EAC) flows southward along the coast south of 25°S. However, we note that the EAC does not generally flow along the coast between 25°S and Brisbane and that transport alongshore in this region and in the Southern GBR is often in a Northerly direction e.g., see Middleton et al. (1994) and Fig. 1 in Bell et al. (2014). Furnas et al. suggest that there is no evidence of increased gelatinous zooplankton in GBR waters. However, we note that AIMS data collected more than three decades ago (Fig. 6 in Bell et al. 2014) support the hypothesis that increased growth of jellyfish will be promoted in eutrophic conditions. Overall, Furnas et al. suggest that there is a lack of relevant data to support some of our assertions/hypotheses. We agree that more data should be collected to better assess the impacts of STP discharges and links between eutrophication and the proliferation of the COTS larvae, jellyfish, diazotrophs, and CSD precursors. The current GBR research/monitoring programs are incapable of doing this; we recommend that a series of regular cross-shelf water-quality/ecological monitoring programs be established to collect the required data.

Long-term monitoring data show that hard coral cover on the Great Barrier Reef (GBR) has reduced by >70 % over the past century. Although authorities and many marine scientists were in denial for many years, it is now widely accepted that this reduction is largely attributable to the chronic state of eutrophication that exists throughout most of the GBR. Some reefs in the far northern GBR where the annual mean chlorophyll a (Chl a) is in the lower range of the proposed Eutrophication Threshold Concentration for Chl a (~0.2-0.3 mg m⁻³) show little or no evidence of degradation over the past century. However, the available evidence suggests that coral diseases and the crown-of-thorns starfish will proliferate in such waters and hence the mandated eutrophication Trigger values for Chl a (~0.4-0.45 mg m⁻³) will need to be decreased to ~0.2 mg m⁻³ for sustaining coral reef communities.

In this study, we investigate the interrelationship between clinical variables and working memory (WM) in Parkinson's disease (PD). Specifically, the aim of the study was to investigate the relationship between disease duration, dopaminergic medication dosage, and motor disability (UPDRS score) with WM in individuals with PD. Accordingly, we recruited three groups of subjects: unmedicated PD patients, medicated PD patients, and healthy controls. All subjects were tested on three WM tasks: short-delay WM, long-delay WM, and the n-back task. Further, PD encompasses a spectrum that can be classified either into akinesia/rigidity or resting tremor as the predominant motor presentation of the disease. In addition to studying medication effects, we tested WM performance in tremor-dominant and akinesia-dominant patients. We further correlated WM performance with disease duration and medication dosage. We found no difference between medicated and unmedicated patients in the short-delay WM task, but medicated patients outperformed unmedicated patients in the long-delay WM and n-back tasks. Interestingly, we also found that akinesia-dominant patients were more impaired than tremor-dominant patients at various WM measures, which is in agreement with prior studies of the relationship between akinesia symptom and basal ganglia dysfunction. Moreover, the results show that disease duration inversely correlates with more demanding WM tasks (long-delay WM and n-back tasks), but medication dosage positively correlates with demanding WM performance. In sum, our results show that WM impairment in PD patients depend on cognitive domain (simple vs. demanding WM task), subtype of PD patients (tremor- vs. akinesia-dominant), as well as disease duration and medication dosage. Our results have implications for the interrelationship between motor and cognitive processes in PD, and for understanding the role of cognitive training in treating motor symptoms in PD.

Ornithine transcarbamylase deficiency (OTCD) is the most common inborn error of urea synthesis. Complete OTCD can result in hyperammonemic coma in the neonatal period, which can rapidly become fatal. Current acute therapy involves dialysis; chronic therapy involves the stimulation of alternate nitrogen clearance pathways; and the only curative approach is liver transplantation. Adeno-associated virus (AAV) vector-based gene therapy would add to current treatment options provided the vector delivers high level and stable transgene expression in liver without dose-limiting toxicity. In this study, we employed an AAV2/8-based self-complementary (sc) vector expressing the murine OTC ( mOTC ) gene under a liver-specific thyroxine-binding globulin promoter and examined the therapeutic effects in a mouse model of OTCD, the spf ash mouse. Seven days after a single intravenous injection of vector, treated mice showed complete normalization of urinary orotic acid, a measure of OTC activity. We further improved vector efficacy by incorporating a Kozak or Kozak-like sequence into mOTC complementary DNA, which increased the OTC activity by five or twofold and achieved sustained correction of orotic aciduria for up to 7 months. Our results demonstrate that vector optimizations can significantly improve the efficacy of gene therapy.

Background: Adeno-associated viral vector (AAV)-mediated and muscle-directed gene therapy is a safe and non-invasive approach to treatment of hemophilia B and other genetic diseases. However, low efficiency of transduction, inhibitor formation and high prevalence of pre-existing immunity to the AAV capsid in humans remain as main challenges for AAV2-based vectors using this strategy. Vectors packaged with AAV7, 8 and 9 serotypes have improved gene transfer efficiencies and may provide potential alternatives to overcome these problems. Objective: To compare the long-term expression of canine factor IX (cFIX) levels and anti-cFIX antibody responses following intramuscular injection of vectors packaged with AAV1, 2, 5, 7, 8 and 9 capsid in immunocompetent hemophilia B mice. Results: Highest expression was detected in mice injected with AAV2/8 vector (28% of normal), followed by AAV2/9 (15%) and AAV2/7 (10%). cFIX expression by AAV2/1 only ranged from 0 to 5% of normal levels. High incidences of anti-cFIX inhibitor (IgG) were detected in mice injected with AAV2 and 2/5 vectors, followed by AAV2/1. None of the mice treated with AAV2/7, 2/8 and 2/9 developed inhibitors or capsid T cells. Conclusions: AAV7, 8 and 9 are more efficient and safer vectors for muscle-directed gene therapy with high levels of transgene expression and absence of inhibitor formation. The absence of antibody response to transgene by AAV7, 8 and 9 is independent of vector dose but may be due to the fact that these three serotypes are associated with high level distribution to, and transduction of, hepatocytes following i.m. injection.

The results from the multimillion dollar Enrichment of Nutrients on Coral Reefs Experiment (ENCORE) on One Tree Island Reef (OTIR) suggest that increased nutrient loads to coral reefs will have little or no effect on the algal growth rates and, hence, on the associated effects that increased algal growth might have on the functioning and stability of coral reefs. However, a comparison of the concentrations of nutrients within the OTIR lagoon with the proposed nutrient threshold concentrations (NTC) for coral reefs suggests that all sites, including the control sites, were saturated with nutrients during ENCORE, and, hence, one would not expect to get any differences between treatments in the algal-growth related measurements. Thus, ENCORE results provide strong support for the proposed NTCs and support the ecological principle that algal productivity and, consequently, the functioning of coral reefs are sensitive to small changes in the background concentrations of nutrients. The principal conclusion of ENCORE, namely that the addition of nutrients did not cause the "pristine" OTIR to convert from coral communities to algal dominated reefs, is contrary to the fact that there was prolific macroalgal growth on the walls and crests of the experimental microatolls by the end of ENCORE.

The relative importance of the additions of iron (Fe), phosphorus (P) and the chelating agent EDTA in promoting the growth of Lyngbya majuscula in waters collected from the NW region of Moreton Bay was investigated using a series of continuous-flow growth studies. In addition, the possible impact of sewage/waste-water treatment plant (WWTP) discharges on the growth of L. majuscula was investigated in a series of batch and semi-continuous-flow growth studies. A preliminary study on the potential of phytoplankton growth in the receiving waters to affect the productivity of L. majuscula was also conducted. The results from the continuous-flow growth studies show that the growth rates of L. majuscula in the NW Moreton Bay waters were stimulated by the addition of EDTA alone but were not stimulated by the addition of P. The additions of P + EDTA, FeEDTA and P + FeEDTA did not result in higher growth rates than those obtained by the addition of EDTA alone. These results demonstrate that the productivity of L. majuscula in the NW Moreton Bay waters was not limited by P and that the addition of Fe did not affect the productivity. The stimulation effect of EDTA could be due to various reasons but we hypothesise that the principal reason for the stimulation is that EDTA increases the bioavailability of non-labile Fe species already present in the water. The results of the batch and semi- continuous-flow growth studies show that diluted (100:1) WWTP discharge water and the receiving waters impacted by WWTP discharges supported significant growth of L. majuscula and that the addition of EDTA to those waters increased the growth potential of L. majuscula. Also the growth of phytoplankton in a sample of the receiving waters impacted by WWTP discharges significantly reduced the growth rate of L. majuscula but the addition of EDTA restored the growth rate to near its maximum value. These results suggest that phytoplankton growth (and probably that of the associated bacterioplankton) could reduce the bioavailability of trace chemical factors needed for the growth of L. majuscula in Moreton Bay and in particular, could reduce the bioavailability of Fe. Overall the results support the hypothesis that growth of L. majuscula in Moreton Bay is often limited by the bioavailability of Fe and the principal reason for this is the lack of supply of suitable organic ligands/chelators, not the lack of Fe per se.

Cultures of Trichodesmium from the Northern and Southern Great Barrier Reef Lagoon (GBRL) have been established in enriched seawater and artificial seawater media. Some cultures have been maintained with active growth for over 6 years. Actively growing cultures in an artificial seawater medium containing organic phosphorus (glycerophosphate) as the principal source of phosphorus have also been established. Key factors that contributed to the successful establishment of cultures were firstly, the seed samples were collected from depth, secondly, samples were thoroughly washed and thirdly, incubations were conducted under relatively low light intensities (PAR ∼ 40–50 μmol quanta m−2 s−1). N2 fixation rates of the cultured Trichodesmium were found to be similar to those measured in the GBRL. Specific growth rates of the cultures during the exponential growth phase in all enriched media were in the range 0.2–0.3 day−1 and growth during this phase was characterised by individual trichomes (filaments) or small aggregations of two to three trichomes. Characteristic bundle formation tended to occur following the exponential growth phase, which suggests that the bundle formation was induced by a lack of a necessary nutrient e.g. Fe. Results from some exploratory studies showed that filament-dominated cultures of Trichodesmium grew over a range of relatively low irradiances (PAR ∼ 5–120 μmol quanta m−2 s−1) with the maximum growth occurring at ∼ 40–50 μmol quanta m−2 s−1. These results suggest that filaments of the tested strain are well adapted for growth at depth in marine waters. Other studies showed that growth yields were dependent on salinity, with maximum growth occurring between 30 and 37 psu. Also the cell yields decreased by an order of magnitude with the reduction of Fe additions from 450 to 45 nM. No active growth was observed with the 4.5 nM Fe addition.

The influence of light intensity and light quality on the growth, N2 fixation and pigmentation of cultures of the cyanobacterium Trichodesmium GBRTRLI101 were investigated under defined laboratory conditions. Both growth rate and N2 fixation rate were strongly dependent on light intensity. The N2 fixation rate increased with light intensity over the whole range tested (PAR 10–160 μmol quanta m−2 s−1) but the growth rate passed through a maximum in the range 45–75 μmol quanta m−2 s−1. Growth rates were the highest under white and yellow light and were significantly reduced under red light. The results also showed that the cellular concentrations of chlorophyll a and phycobiliproteins (PBPs) increased under low light conditions and were affected by light quality. Overall the results suggest that the availability of light and the quality of that light play an important role in the growth and distribution of Trichodesmium in coastal and oceanic waters.