Movement patterns and habitat use of the exploited swimming crab Scylla serrata (Forskal, 1775)

Mangrove ecosystems are highly productive, providing habitat for a variety of species, of which many are harvested. In times of rapid global change, due to natural as well as anthropogenic drivers, these ecosystems are increasingly placed at risk, and so are the species living within them. The mud crab Scylla serrata (Portunidae) (ForskÃÂÂ¥l, 1775) is a highly valued and exploited species associated with mangrove ecosystems in the Indo-West-Pacific. Its complex life-cycle includes a dispersing larval phase and a benthic phase as juveniles and adults. The planktonic larvae are restricted to oceanic waters, since they are stenohaline and therefore dependent on stable, high salinity conditions in order to survive. Benthic juveniles and adults are physiologically adapted to changing temperatures and varying salinities, conditions that typically occur in mangrove habitats. Movement and habitat use of large juveniles and adults are well studied and these life stages are known to move between various mangrove habitats including intertidal mangrove area flats as well as subtidal channels and flats. Females undertake long distance movements from brackish inshore waters to waters with oceanic conditions for (supposed) spawning. However, little is known about larval stages, and early benthic stages are underrepresented in the literature. The aim of this thesis is to provide deeper insights into movement patterns and habitat use at these particular life stages and to understand how these characteristics might be affected by environmental factors, such as seascape and rainfall

Ocular hypotensive effect of fixed-combination brinzolamide/brimonidine adjunctive to a prostaglandin analog: a randomized clinical trial

To determine whether intraocular pressure (IOP) lowering with fixed-combination brinzolamide/brimonidine (BBFC) adjunctive to a prostaglandin analog (PGA) was superior to that of vehicle+PGA in patients with open-angle glaucoma or ocular hypertension who were inadequately controlled with PGA monotherap

Safety and Efficacy of Adding Fixed-Combination Brinzolamide/Timolol Maleate to Prostaglandin Therapy for Treatment of Ocular Hypertension or Glaucoma

Purpose. To evaluate the safety and efficacy of adding brinzolamide 1%/timolol maleate 0.5% fixed combination (BTFC) to a prostaglandin analog (PGA). Methods. This was a 12-week, open-label, single-arm study of patients with open-angle glaucoma or ocular hypertension with intraocular pressure (IOP) not sufficiently controlled after ≥4 weeks of PGA monotherapy. The primary outcome was mean IOP change from baseline at week 12. Other outcomes included IOP change from baseline at week 4, percentage of patients achieving IOP ≤18 mmHg at week 12, and patient experience survey responses at week 12. Results. Forty-seven patients were enrolled and received treatment. The most commonly used PGAs were latanoprost (47%) and travoprost (32%). Mean ± SD IOP was decreased at week 12 (17.2 ± 4.1 mmHg) compared with baseline (23.1 ± 3.0 mmHg; P<0.001, paired t-test); IOP at week 4 was 17.2 ± 3.3 mmHg. At week 12, 70% of patients achieved IOP ≤18 mmHg. Patient-reported symptoms (e.g., pain and redness) were mostly unchanged from baseline. Twenty-eight adverse events (AEs) were reported; the most frequently reported AE was headache (3 events in 2 patients). Conclusion. Adjunctive BTFC + PGA therapy was effective and well tolerated. IOP decreased by 6 mmHg at weeks 4 and 12

Stochastic dynamics of single molecules across phase boundaries

We discuss the stochastic trajectories of single molecules in a phase-separated liquid, when a dense and a dilute phase coexist. Starting from a continuum theory of macroscopic phase separation we derive a stochastic Langevin equation for molecular trajectories that takes into account thermal fluctuations. We find that molecular trajectories can be described as diffusion with drift in an effective potential, which has a steep gradient at phase boundaries. We discuss how the physics of phase coexistence affects the statistics of molecular trajectories and in particular the statistics of displacements of molecules crossing a phase boundary. At thermodynamic equilibrium detailed balance imposes that the distributions of displacements crossing the phase boundary from the dense or from the dilute phase are the same. Our theory can be used to infer key phase separation parameters from the statistics of single-molecule trajectories. For simple Brownian motion, there is no drift in the presence of a concentration gradient. We show that interactions in the fluid give rise to an average drift velocity in concentration gradients. Interestingly, under non-equilibrium conditions, single molecules tend to drift uphill the concentration gradient. Thus, our work bridges between single-molecule dynamics and collective dynamics at macroscopic scales and provides a framework to study single-molecule dynamics in phase-separating systems

Effect of diet on growth, survival and fatty acid profile of marine amphipods: implications for utilisation as a feed ingredient for sustainable aquaculture

Rapidly expanding fed aquaculture demands high-quality, sustainable nutrient sources for utilisation as dietary ingredients. Exploring the potential of under-utilised resources from other industries is imperative to replace finite natural resources, such as fish meal. Marine gammarids may be an excellent source of essential fatty acids; however, their aquaculture using formulated diets remains untested in terms of survival, growth and nutritional value of the cultured product. Here, juveniles of 2 marine gammarid species, Gammarus locusta and Echinogammarus marinus, were maintained in controlled feeding experiments with 2 marine diets (Ulva spp. and Fucus spp.) and 2 terrestrial diets (lupin meal and carrot leaves). G. locusta exhibited higher survival rates, particularly when fed carrot leaves, an agricultural waste product. Fatty acid profiles of the resulting G. locusta product appear well suited for marine finfish nutrition, indicating high suitability of G. locusta as an aquaculture diet source. In contrast, whilst E. marinus may provide beneficial fatty acid profiles for aquatic animal nutrition, its poor growth performance in this study indicates that further dietary/culture research is required for this species. Our results indicate, for the first time, that marine gammarids are capable of trophic upgrading and can use non-marine diets for healthy growth in culture, but their suitability as a formulated feed ingredient for specific fish or crustacean species needs to be investigated individually. Future research should include the development of optimal large-scale production as well as investigation of optimal methods of inclusion of gammarids as feed ingredient for target aquaculture species

Quantitative theory for the diffusive dynamics of liquid condensates

Key processes of biological condensates are diffusion and material exchange with their environment. Experimentally, diffusive dynamics are typically probed via fluorescent labels. However, to date, a physics-based, quantitative framework for the dynamics of labeled condensate components is lacking. Here, we derive the corresponding dynamic equations, building on the physics of phase separation, and quantitatively validate the related framework via experiments. We show that by using our framework, we can precisely determine diffusion coefficients inside liquid condensates via a spatio-temporal analysis of fluorescence recovery after photobleaching (FRAP) experiments. We showcase the accuracy and precision of our approach by considering space- and time-resolved data of protein condensates and two different polyelectrolyte-coacervate systems. Interestingly, our theory can also be used to determine a relationship between the diffusion coefficient in the dilute phase and the partition coefficient, without relying on fluorescence measurements in the dilute phase. This enables us to investigate the effect of salt addition on partitioning and bypasses recently described quenching artifacts in the dense phase. Our approach opens new avenues for theoretically describing molecule dynamics in condensates, measuring concentrations based on the dynamics of fluorescence intensities, and quantifying rates of biochemical reactions in liquid condensates

Effects of cold winters and roost site stability on population development of non-native Asian ring-necked parakeets (Alexandrinus manillensis) in temperate Central Europe – Results of a 16-year census

Asian ring-necked parakeets (Alexandrinus manillensis, formerly Psittacula krameri, hereafter RNP) first bred in&nbsp;Germany in 1969. Since then, RNP numbers increased in all three major German subpopulations (Rhineland,&nbsp;Rhine-Main, Rhine-Neckar) over the period 2003–2018. In the Rhine-Neckar region, the population increased to more than fivefold within only 15 years. Interestingly, there was no significant breeding range expansion of &nbsp;RNP in the period 2010–2018. In 2018, the total number of RNP in Germany amounted to &gt;16,200 birds. Differences&nbsp;in RNP censuses between years were evident. Surprisingly, cold winters (extreme value, −13.7 °C) and&nbsp;cold weather conditions in the breeding season (coldest month average, −1.36 °C) were not able to explain&nbsp;between-year variation. This finding suggests that in general winter mortality is low – with exceptions for winters&nbsp;2008/2009 and 2009/2010, and a population-relevant loss of broods is low in our study population.&nbsp;Surprisingly, the social behaviour in terms of spatio-temporal stability of roost sites could well explain positive and negative population trends. Years of spatially stable and regularly used roost sites seem to correlate with increasing population sizes. In contrast, known shifts of RNP among different roost sites or the formations of&nbsp;new roost sites by split are related to population stagnation or a decrease in numbers. Climate change may lead&nbsp;to further range expansion as cities not suitable yet for RNP may become so in the near future.

Amphipod meal in formulated diets for juvenile turbot Psetta maxima

Increasing fish meal prices and the depletion of natural fish stock due to fish meal production demands for novel feed ingredients in aquaculture. Marine amphipods are a natural food source for many flatfish species and are rich in essential fatty acids hence strong candidates as fish meal replacement in aquafeeds. Recent studies showed promising fatty acid profiles and fatty acid synthesis in marine amphipods, which could lower the need for fish oil supplementation in finfish feeds. In this study, juvenile turbot Psetta maxima were fed with four different diets containing different levels of amphipod meal as fish meal replacement: 0, 50 and 100 % of replacement and commercial turbot feed as reference. The experimental diets were formulated regarding basic nutritional demands without fish oil added. Growth performance as well as lipid classes and fatty acid profile in muscle and liver tissue in response to different feeding regimes were investigated

Regulated Activation of the PAR Polarity Network Ensures a Timely and Specific Response to Spatial Cues

How do cells polarize at the correct time and in response to the correct cues? In the C. elegans zygote, the timing and geometry of polarization rely on a single dominant cue-the sperm centrosome-that matures at the end of meiosis and specifies the nascent posterior. Polarization requires that the conserved PAR proteins, which specify polarity in the zygote, be poised to respond to the centrosome. Yet, how and when PAR proteins achieve this unpolarized, but responsive, state is unknown. We show that oocyte maturation initiates a fertilization-independent PAR activation program. PAR proteins are initially not competent to polarize but gradually acquire this ability following oocyte maturation. Surprisingly, this program allows symmetry breaking even in unfertilized oocytes lacking centrosomes. Thus, if PAR proteins can respond to multiple polarizing cues, how is specificity for the centrosome achieved? Specificity is enforced by Polo-like and Aurora kinases (PLK-1 and AIR-1 in C. elegans), which impose a delay in the activation of the PAR network so that it coincides with maturation of the centrosome cue. This delay suppresses polarization by non-centrosomal cues, which can otherwise trigger premature polarization and multiple or reversed polarity domains. Taken together, these findings identify a regulatory program that enforces proper polarization by synchronizing PAR network activation with cell cycle progression, thereby ensuring that PAR proteins respond specifically to the correct cue. Temporal control of polarity network activity is likely to be a common strategy to ensure robust, dynamic, and specific polarization in response to developmentally deployed cues