Diamagnetism versus Paramagnetism in charged spin-1 Bose gases

It has been suggested that either diamagnetism or paramagnetism of Bose gases, due to the charge or spin degrees of freedom respectively, appears solely to be extraordinarily strong. We investigate magnetic properties of charged spin-1 Bose gases in external magnetic field, focusing on the competition between the diamagnetism and paramagnetism, using the Lande-factor $g$ of particles to evaluate the strength of paramagnetic effect. We propose that a gas with $g<{1/\sqrt{8}}$ exhibits diamagnetism at all temperatures, while a gas with $g>{1/2}$ always exhibits paramagnetism. Moreover, a gas with the Lande-factor in between shows a shift from paramagnetism to diamagnetism as the temperature decreases. The paramagnetic and diamagnetic contributions to the total magnetization density are also calculated in order to demonstrate some details of the competition.Comment: 6 pages, 5 figure

Impact of Background on Color Performance of False Clown???sh, Amphiprion ocellaris, Cuvier

Color performance of false clown???sh, Amphiprion ocellaris, Cuvier was ???rst examined at four color backgrounds (blue, green red, and white) for 4 wk, then all ???sh were transferred to a white background for another 4 wk to test whether the impact of background colors on ???sh skin could have a lasting effect when the environment colors are changed. The experiment was conducted in 10-L rectangular plastic buckets with three replicates. Thirty ???sh were stocked in each bucket and three ???sh were randomly sampled from each tank in Weeks 1, 4, and 8. The color hue, saturation, and brightness were quanti???ed using image analysis. In addition to the whole body analysis, each ???sh image was divided into ventral and dorsal parts to examine the body position-dependent response. Furthermore, color differences among the dorsal ???n, anal ???n, ventral ???n, and caudal ???n were also quanti???ed. Blue or green background enhanced red orange color on ???sh skin, whereas white background made ???sh color brighter. Irrespective of background color, the dorsal side of ???sh exhibited more red orange, but the color was less bright and less saturated than that of ventral side. Upper ???ns (dorsal and caudal ???ns) were more red orange in a blue background than in a white background. Transferring ???sh from colored backgrounds to a white background made the ???sh skin and ???ns brighter, the color of ventral body and ventral ???ns less saturated, and the bottom ???ns more yellow orange. The results indicate that blue or green background could strengthen the orange color, whereas white background made ???sh color less saturated but brighter. The impact of background on the performance of ???sh color is temporary and likely to disappear when environmental color changes

Renormalized one-loop theory of correlations in polymer blends

The renormalized one-loop theory is a coarse-grained theory of corrections to the self-consistent field theory (SCFT) of polymer liquids, and to the random phase approximation (RPA) theory of composition fluctuations. We present predictions of corrections to the RPA for the structure function $S(k)$ and to the random walk model of single-chain statics in binary homopolymer blends. We consider an apparent interaction parameter $\chi_{a}$ that is defined by applying the RPA to the small $k$ limit of $S(k)$. The predicted deviation of $\chi_{a}$ from its long chain limit is proportional to $N^{-1/2}$, where $N$ is chain length. This deviation is positive (i.e., destabilizing) for weakly non-ideal mixtures, with \chi_{a} N \alt 1, but negative (stabilizing) near the critical point. The positive correction to $\chi_{a}$ for low values of $\chi_{a} N$ is a result of the fact that monomers in mixtures of shorter chains are slightly less strongly shielded from intermolecular contacts. The depression in $\chi_{a}$ near the critical point is a result of long-wavelength composition fluctuations. The one-loop theory predicts a shift in the critical temperature of ${\cal O}(N^{-1/2})$, which is much greater than the predicted ${\cal O}(N^{-1})$ width of the Ginzburg region. Chain dimensions deviate slightly from those of a random walk even in a one-component melt, and contract slightly with increasing $\chi_{e}$. Predictions for $S(k)$ and single-chain properties are compared to published lattice Monte Carlo simulations.Comment: submitted to J. Chem. Phy

Renormalization of the one-loop theory of fluctuations in polymer blends and diblock copolymer melts

Attempts to use coarse-grained molecular theories to calculate corrections to the random-phase approximation (RPA) for correlations in polymer mixtures have been plagued by an unwanted sensitivity to the value of an arbitrary cutoff length, {\it i.e.}, by an ultraviolet (UV) divergence. We analyze the UV divergence of the inverse structure factor $S^{-1}(k)$ predicted by a `one-loop' approximation similar to that used in several previous studies. We consider both miscible homopolymer blends and disordered diblock copolymer melts. We show, in both cases, that all UV divergent contributions can be absorbed into a renormalization of the values of the phenomenological parameters of a generalized self-consistent field theory (SCFT). This observation allows the construction of a UV convergent theory of corrections to SCFT phenomenology. The UV-divergent one-loop contribution to $S^{-1}(k)$ are shown to be the sum of: (i) a $k$-independent contribution that arises from a renormalization of the effective $\chi$ parameter, (ii) a $k$-dependent contribution that arises from a renormalization of monomer statistical segment lengths, (iii) a contribution proportional to $k^{2}$ that arises from a square-gradient contribution to the one-loop fluctuation free energy, and (iv) a $k$-dependent contribution that is inversely proportional to the degree of polymerization, which arises from local perturbations in fluid structure near chain ends and near junctions between blocks in block copolymers.Comment: 35 pages, 2 figure

Molecular Cloning and Response to Water Temperature and Nutrient Manipulation of Insulin-like Growth Factor (IGF) Genes in Golden Pompano Trachinotus ovatus (Linnaeus 1758) Larvae

In this study, insulin-like growth factor I (IGF I) and IGF II in golden pompano larvae were cloned and analyzed. In the first trial, IGF expression during ontogeny of larvae in the first 18-days of their life was explored, and then the response of IGFs to water temperature (23, 26, and 29oC) on 12 day post hatching (DPH) and 18 DPH were compared. On 28 DPH, the response of IGFs to the manipulation of nutrients was evaluated. The expression of IGF I increased with the increase of fish age, and was not significantly affected by water temperature. The expression of IGF II was affected by water temperature on 12 DPH and 18 DPH. The expression of IGF II at 23oC was significantly higher than at 26oC and 29oC. The expression of IGFs in fish larvae on 28 DPH was not concomitant with nutrient manipulation. This study detected the gene expression of IGFs at the early stage of golden pompano larvae. The time dependent expression of IGF genes in fish larvae is important to understand the ontogenetic development and growth of fish larvae in early life

Casimir effect for the massless Dirac field in two-dimensional Reissner-Nordstr\"{o}m spacetime

In this paper, the two-dimensional Reissner-Nordstr\"{o}m black hole is considered as a system of the Casimir type. In this background the Casimir effect for the massless Dirac field is discussed. The massless Dirac field is confined between two ``parallel plates'' separated by a distance $L$ and there is no particle current drilling through the boundaries. The vacuum expectation values of the stress tensor of the massless Dirac field at infinity are calculated separately in the Boulware state, the Hartle-Hawking state and the Unruh state.Comment: 10 pages, no figure. Accepted for publication in IJMP

Effect of Dietary Carotenoids on Skin Color and Pigments of False Clown???sh, Amphiprion ocellaris, Cuvier

This study evaluated the role of supplemented dietary carotenoids in regulating the skin color and pigments of the false clown???sh, Amphiprion ocellaris. Three carotenoid types, such as astaxanthin, ??-carotene, and canthaxanthin, were added to the basal diet at four pigment doses (0, 20, 50, and 100 ppm). Carotenoid diets were feed for 5 wk and then withdrawn from the diet for three additional wk during an 8-wk trial. The dose of each diet did not change the overall color hue, brightness, or saturation, but astaxanthin was the only carotenoid that enhanced red hue by the end of Week 5. The withdrawal of astaxanthin from the diet did not reduce the red hue, but reduced saturation. In contrast, the withdrawal of dietary ??-carotene or canthaxanthin reduced color saturation and brightness, but did not affect color hue. Dietary astaxanthin increased skin astaxanthin in Week 1 and skin zeaxanthin in Week 5. The withdrawal of astaxanthin escalated skin canthaxanthin and zeaxanthin by Week 8. Dietary ??-carotene suppressed skin ??-carotene, but enhanced skin zeaxanthin by Week 8. Although skin canthaxanthin was enhanced by dietary ??-carotene from Week 5 onward, dietary ??-carotene at 100 ppm maximized skin canthaxanthin by Week 8. Interestingly, dietary canthaxanthin suppressed skin canthaxanthin and zeaxanthin, but increased ??-carotene. This study suggests that astaxanthin has the potential to enhance the red hue on clown???sh skin and its withdrawal from the diet did not fade the red hue of the skin

Effect of Light Intensity on Color Performance of False Clown???sh, Amphiprion ocellaris Cuvier

Color performance of false clown???sh, Amphiprion ocellaris Cuvier, was examined under three levels of light intensity (20???50 , 600???850 , and 2700???3500 lx) for 5 wk. The experiment was conducted in nine rectangular glass aquaria (25 3 25 3 20 cm) with three replicates. Each aquarium was stocked with 36 ???sh, and 3 ???sh were randomly sampled from each aquarium every other week. Digital images were taken weekly on each individual ???sh after it was anesthetized in MS-222. The color performance in hue, saturation, and brightness was quanti???ed using image analysis. In addition to the whole-body analysis, each ???sh image was divided into ventral and dorsal parts to assess the body position-dependent effect. Furthermore, color differences between dorsal ???n, anal ???n, ventral ???n, and caudal ???n were also quanti???ed. The whole body was brighter at low light than at medium or at high light intensity. Irrespective of light intensity, the dorsal side was more orange but less bright than the ventral side. Brighter light strengthened overall orange color on ???sh ???ns. The dorsal ???n and ventral ???ns appeared more orange than the anal and caudal ???ns regardless of light intensity and exposure duration. Similar to body color, low light also led to brighter ???ns, especially for caudal and dorsal ???ns. Our results indicate that ambient light could regulate ???sh color performance but could not change the pigment dominance by b-carotene. Light intensity is unlikely to change the contrast between dorsal and ventral sides, but dim light tends to make ???sh body brighter, and bright light strengthens orange color on ???ns

Improvement of post-thaw sperm survivals using liquid nitrogen vapor in a spermcasting oyster Ostrea angasi

© 2017 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 12 month embargo from date of publication (Aug 2017) in accordance with the publisher’s archiving policyLow survival of cryopreserved sperm impedes the application of cryopreservation technique in spermcasting oyster species. This study developed a simple method of liquid nitrogen vapor freezing to improve post-thaw sperm survival in the spermcasting oyster Ostrea angasi. The results indicate that the permeable cryoprotectants, dimethyl sulfoxide (DMSO), ethylene glycol (EG) and propylene glycol (PG) were non-toxic to sperm up to 20% concentration and 90 min exposure whereas methanol at 10% or higher was toxic to sperm for any exposure over 30 min. Among the treatments with permeable cryoprotectants, 15% EG produced the highest post-thaw sperm motility. Sperm motility was further improved by the addition of non-permeable cryoprotectants (trehalose and glucose), with 15% EG + 0.2 M trehalose resulting in the highest post-thaw sperm motility among all the combinations evaluated. The durations of 20, 30 and 60 min equilibrations produced a higher post-thaw sperm motility and plasma membrane integrity (PMI) than 10 min. Higher post-thaw motility and PMI were achieved by freezing sperm at the 8 cm height from the liquid nitrogen surface than at the 2, 4, 6, 10 or 12 cm height. Holding sperm for 10 min in liquid nitrogen vapor produced higher post-thaw motility and PMI than for 2, 5 or 20 min. The cryopreservation protocol developed in this study improved both post-thaw motility and PMI of O. angasi sperm at least 15% higher than those cryopreserved using programmable freezing method. Liquid nitrogen vapor freezing might have greater applicability in improving post-thaw sperm quality of spermcasting oyster species

Interfacial Stresses on Droplet Interface Bilayers Using Two Photon Fluorescence Lifetime Imaging Microscopy

Response of lipid bilayers to external mechanical stimuli is an active area of research with implications for fundamental and synthetic cell biology. However, there is a lack of tools for systematically imposing mechanical strains and non-invasively mapping out interfacial (membrane) stress distributions on lipid bilayers. In this article, we report a miniature platform to manipulate model cell membranes in the form of droplet interface bilayers (DIBs), and non-invasively measure spatio-temporally resolved interfacial stresses using two photon fluorescence lifetime imaging of an interfacially active molecular flipper (Flipper-TR). We established the effectiveness of the developed framework by investigating interfacial stresses accompanying three key processes associated with DIBs: thin film drainage between lipid monolayer coated droplets, bilayer formation, and bilayer separation. Interestingly, the measurements also revealed fundamental aspects of DIBs including the existence of a radially decaying interfacial stress distribution post bilayer formation, and the simultaneous build up and decay of stress respectively at the bilayer corner and center during bilayer separation. Finally, utilizing interfacial rheology measurements and MD simulations, we also reveal that the tested molecular flipper is sensitive to membrane fluidity that changes with interfacial stress - expanding the scientific understanding of how molecular motors sense stress.Comment: 8 pages, 4 figure