Movement of Bigmouth Sleeper, Gobiomorus dormitor, in the Río Cañas, Puerto Rico, revealed by radio telemetry, and a discussion of the species’ amphidromous characterization

Bigmouth Sleeper, Gobiomorus dormitor, are tropical fish native to rivers of Puerto Rico. They are popular sport fish targeted by local anglers. They are considered as diadromous, but this characterization is controversial. The displacement of Bigmouth Sleepers in the Río Cañas, Puerto Rico, was examined using radio telemetry. Twenty fish were radio-tagged and monitored from January to November 2008. Fish were in the Río Cañas 69%, 62%, and 59% of the time before (January-May), during (June-August), and after (September-November) the spawning season, respectively. Average detected linear home range (within the river) for all tracking periods was 2.3 km, but varied from less than 0.1 km to 8.1 km. Detected linear home range was not related to weight class or sex. They may remain in freshwater as juveniles and adults, only spending their larval stage in estuarine or marine habitats (i.e. amphidromous diadromy). However, they can complete their larval stage in freshwater but appear to make periodic migrations to the marine environment as adults, as suggested by this study. The best descriptor of Bigmouth Sleeper is that of a facultative amphidromous euryhaline species. Fishery and habitat management for this fish should take into consideration their general migratory behavior and their plasticity with respect to this life history strategy

Polystyrene-block-poly (methoxy diethylene glycol acrylate)-block-polystyrene triblock copolymers in aqueous solution—a SANS study of the temperature-induced switching behavior

A concentrated solution of a symmetric triblock copolymer with a thermoresponsive poly(methoxy diethylene glycol acrylate) (PMDEGA) middle block and short hydrophobic, fully deuterated polystyrene end blocks is investigated in D2O where it undergoes a lower critical solution temperature-type phase transition at ca. 36 °C. Small-angle neutron scattering (SANS) in a wide temperature range (15–50 °C) is used to characterize the size and inner structure of the micelles as well as the correlation between the micelles and the formation of aggregates by the micelles above the cloud point (CP). A model featuring spherical core-shell micelles, which are correlated by a hard-sphere potential or a sticky hard-sphere potential together with a Guinier form factor describing aggregates formed by the micelles above the CP, fits the SANS curves well in the entire temperature range. The thickness of the thermoresponsive micellar PMDEGA shell as well as the hard-sphere radius increase slightly already below the cloud point. Whereas the thickness of the thermoresponsive micellar shell hardly shrinks when heating through the CP and up to 50 °C, the hard-sphere radius decreases within 3.5 K at the CP. The volume fraction decreases already significantly below the CP, which may be at the origin of the previously observed gel–sol transition far below the CP (Miasnikova et al., Langmuir 28: 4479–4490, 2012). Above the CP, small, and at higher temperatures, large aggregates are formed by the micelles

Stimuli-Responsive Amphiphilic Polyelectrolyte Heptablock Copolymer Physical Hydrogels: An Unusual pH-Response

An amphiphilic cationic polyelectrolyte based on poly[2-(dimethylamino)ethyl methacrylate] (polyDMA) and poly(n-butyl methacrylate) (polyBuMA) with a BuMA–DMA–BuMA–DMA–BuMA–DMA–BuMA heptablock copolymer architecture was studied in aqueous media. This copolymer was found to form a physical hydrogel via the intermolecular hydrophobic association (physical cross-linking) of the BuMA blocks. The rheological properties of the heptablock hydrogels were investigated as a function of copolymer concentration, and pH. The results showed a peculiar pH-dependence of the rheological properties, remarkably different from those observed with associative telechelic polyelectrolytes. Aqueous solutions of this copolymer were free-flowing sols at low pH (below 2) and high pH (above 8), whereas they turned into gels at intermediate pH values. The rheological properties studied as a function of pH showed two additional stiff–soft–stiff gel transitions at pH 4.5 and 6.5. Small-angle neutron scattering revealed the formation of a 3D transient network of bridged flower-like micelles whose structural characteristics, i.e., micellar radius, hard-sphere radius and hard-sphere volume fraction, were smoothly evolving with the pD

Thermoresponsive PS-b-PNIPAM-b-PS Micelles: Aggregation Behavior, Segmental Dynamics, and Thermal Response

Adelsberger J, Kulkarni A, Jain A, et al. Thermoresponsive PS-b-PNIPAM-b-PS Micelles: Aggregation Behavior, Segmental Dynamics, and Thermal Response. Macromolecules. 2010;43(5):2490-2501.We have studied I lie thermal behavior of amphiphilic, symmetric triblock copolymers having short, deuterated polystyrene (PS) end blocks and a large poly(N-isopropylacrylarnicle) (PNIPAM) middle block exhibiting a lower critical solution temperature (LCST) in aqueous solution. A wide range of concentrations (0.1-300 mg/mL) is investigated using it number of analytical methods such as fluorescence correlation spectroscopy (FCS), turbidimetry, dynamic light scattering (DLS), small-angle neutron scattering (SANS), and neutron spin-echo spectroscopy (NSE). The critical micelle concentration is determined using FCS to be 1 mu M or less. The collapse of the micelles at the LCST is investigated using turbidimetry and DLS and shows a weak dependence on the degree of polymerization of the PNIPAM block. SANS with contrast matching allows its to reveal the core-shell Structure of the micelles as well as their correlation as a function of temperature. The segmental dynamics of the PNIPAM shell are studied as a function of temperature and arc found to be faster in the collapsed state than in the swollen state. The mode detected has a linear dispersion in q(2) and is found to be faster in the collapsed state as compared to the swollen state. We attribute this result to the averaging over mobile and immobilized segments

Stimuli-Responsive Amphiphilic Polyelectrolyte Heptablock Copolymer Physical Hydrogels: An Unusual pH-Response

An amphiphilic cationic polyelectrolyte based on poly­[2-(dimethylamino)­ethyl methacrylate] (polyDMA) and poly­(<i>n</i>-butyl methacrylate) (polyBuMA) with a BuMA–DMA–BuMA–DMA–BuMA–DMA–BuMA heptablock copolymer architecture was studied in aqueous media. This copolymer was found to form a physical hydrogel via the intermolecular hydrophobic association (physical cross-linking) of the BuMA blocks. The rheological properties of the heptablock hydrogels were investigated as a function of copolymer concentration, and pH. The results showed a peculiar pH-dependence of the rheological properties, remarkably different from those observed with associative telechelic polyelectrolytes. Aqueous solutions of this copolymer were free-flowing sols at low pH (below 2) and high pH (above 8), whereas they turned into gels at intermediate pH values. The rheological properties studied as a function of pH showed two additional stiff–soft–stiff gel transitions at pH 4.5 and 6.5. Small-angle neutron scattering revealed the formation of a 3D transient network of bridged flower-like micelles whose structural characteristics, i.e., micellar radius, hard-sphere radius and hard-sphere volume fraction, were smoothly evolving with the pD

Genetic and clinical correlates in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a hereditary disease, which is caused by mutations in genech coding for proteins of carcomere of heart muscle. Disease is characterised by wide genotypic and fenotypic heterogeneity. Since the 90-th of 20-th century, when the first mutation responsible for HCM was identified, many research was done in detecting the correlation between mutant gene and clinical picture of the affected patient. As the first in Czech republic, we determined the frequencies of 4 most common genes in HCM in czech patients. We figured out, that spectrum of mutations is somehow different from another populations. We didn't find any correlation between specific gene mutation and morfologic and clinical characteristics of affected subjects. In our study with AT-1 receptor blocker - candesartan, we demostrated positive effect of candesartan on level of hypertrophy and function of the left heart ventricle and clinical symptoms of the patients with HCM

Additional file 1: of The effects of storage temperature on PBMC gene expression

Supplemental data for Table 1. Provides a list of the 1,367 affected genes that demonstrated an increase or decrease in gene expression greater than 3-fold from 14 month cryopreserved PBMCs after they were thawed as compared to fresh PBMCs. It also contains a list of the 18 genes that were affected more than 3-fold when cryopreserved PBMCs were thawed after 14 months of storage at −150 °C versus −80 °C. (XLSX 191 kb