Larval study revealed diversity and life-history traits of crypto-benthic eel gobies.

Because adult and juvenile eel gobies usually hide within the burrows of muddy substrates, their diversity and life history have not yet been fully elucidated. We investigated larval specimens of the eel gobies collected on Okinawa Island in southern Japan. The genus Trypauchenopsis was previously thought to consist of only one species, but our larval collection identified two species, Trypauchenopsis limicola and Trypauchenopsis intermedia, distinguished by their species-specific melanophore arrangements and differences in their fin-ray counts. Taenioides kentalleni were previously known from only two specimens worldwide. A third specimen of this species has now been added from the larval collection. In addition to the three species above, Taenioides gracilis and Caragobius urolepis were identified and the larval morphologies of the five species were described for the first time. All the larvae collected in the present study were at late postflexion stage. T. limicola, T. intermedia and T. gracilis were presumably collected in the estuaries and beaches when approaching their adult habitats at the end of pelagic life. They were 8.5-10.3 mm in standard length, and otolith analysis suggests that their pelagic larval durations are a little longer than 1 month (average 34-37 days). The larval occurrence suggested that the spawning season of T. limicola is May-December, when the water temperature is warmer than approximately 20°C. Our work reveals that studying the larval stage can provide new information on the taxonomy and life history of the elusive cryptobenthic fish.

Early development and occurrence patterns of the Pagrinae seabream Argyrops bleekeri (Perciformes: Sparidae): Does early life history have implications for sparid relationships?

The early development and occurrence patterns of Argyrops bleekeri are described based on 87 specimens collected from Nakagusuku Bay on Okinawa Island in southwestern Japan. Larvae and juveniles of the genus Argyrops are distinguished from the other seabreams inhabiting the Western Pacific region by the strength and extent of head spination, body depth, dorsal-fin-ray counts and melanophore patterns. Argyrops bleekeri is easily distinguished from other members of this genus by the presence of a single rudimentary dorsal-fin spine on the first dorsal pterygiophore, melanophore patterns and an allopatric distribution. Argyrops bleekeri larvae [3.3-7.1 mm body length (BL)] and juveniles (6.7-13.0 mm BL) were found in the bay from January to May; nonetheless, they were not collected from the outer bay or in extremely shallow inshore areas such as tidal flats. The results suggest that Argyrops is the most derived red seabream because of its spiny morphology, and it may be a member of an expanding nearshore group of red seabreams, which originally inhabited offshore waters.

Comparative age-specific demography of four commercially important deep-water snappers: implication for fishery management of a long-lived lutjanid.

Lutjanid snappers belonging to the subfamilies Apsilinae and Etelinae are commercially valuable components of tropical deep-water fisheries throughout much of the Indo-Pacific region. Based on age assessment using sagittal otoliths, the age-specific demographic characteristics of four deep-water snappers, Etelis coruscans, Paracaesio caerulea, Pristipomoides filamentosus and Pristipomoides sieboldii, in the Okinawa Islands, southwestern Japan, were examined, and the results were discussed for fishery management. Age validation using edge-type analysis demonstrated that opaque zones in all species were formed once per year and were considered valid annual growth increments. The von Bertalanffy growth equations were also determined for each species. These snappers are long-lived (>50 years for E. coruscans and P. caerulea and >30 years for the two species of Pristipomoides) and relatively slow-growing. The age of acquiring sexual maturity in females was relatively later in E. coruscans, P. caerulea and P. filamentosus than in P. sieboldii. The results revealed differences in the biological traits among these four species; E. coruscans and P. caerulea with long life spans and late maturation are particularly more vulnerable to fishing impact than the two Pristipomoides species. Therefore, further approaches to decrease and control fishing intensity, such as networking of marine-protected areas and regulation to control the numbers of boats and/or the total allowable catch, are necessary for the management of the stock of these species, especially for E. coruscans and P. caerulea.

The fibrous tapetum of the horse eye.

The tapetum lucidum is a light-reflective tissue in the eyes of many animals. Many ungulates have a fibrous tapetum. The horse has one of the largest eyes of any living animal and also has excellent vision in low-light environments. This study aimed to clarify the macroscopic tapetal shape, relationship between the tapetal thickness and the degree of pigmentation of the retinal pigment epithelium (RPE), spatial relationship between the visual streak and the tapetum, and wavelength of the light reflected from the tapetum in the horse. Macroscopically, weak light revealed the tapetum as a horizontal band located dorsal to and away from the optic disc. The tapetum expanded dorsally as the illumination increased. The tapetal tissue consisted of lamellae of collagen fibrils running parallel to the retinal surface; these spread over almost the entire ocular fundus and were thicker in the horizontal band dorsal to the disc. Only the horizontal band of the tapetum was covered by unpigmented RPE, suggesting that this band reflects light and is responsible for mesopic and scotopic vision. The visual streak was located in the ventral part of the horizontal band, ventral to the thickest part of the tapetum. The wavelength of the light reflected from the horizontal band of the tapetum was estimated from the diameter and interfibrous distance of the collagen fibrils to be approximately 468 nm. Therefore, the light reflected from the tapetum should be more effectively absorbed by rods than by cones, and should not interfere with photopic vision.

Diamond squid (Thysanoteuthis rhombus)-derived chondroitin sulfate stimulates bone healing within a rat calvarial defect.

Chondroitin sulfate (CS) has been suggested to be involved in bone formation and mineralization processes. A previous study showed that squid-derived CS (sqCS) has osteoblastogenesis ability in cooperation with bone morphogenetic protein (BMP)-4 in vitro. However, in vivo, osteogenic potential has not been verified. In this study, we created a critical-sized bone defect in the rat calvaria and implanted sqCS-loaded gelatin hydrogel sponges (Gel) into the defect with or without BMP-4 (CS/BMP/Gel and CS/Gel, respectively). At 15 weeks, bone repair rate of CS/Gel-treated defects and CS/BMP/Gel-treated defects were 47.2% and 51.1%, respectively, whereas empty defects and defects with untreated sponges showed significantly less bone ingrowth. The intensity of von Kossa staining of the regenerated bone was less than that of the original one. Mineral apposition rates at 9 to 10 weeks were not significantly different between all treatment groups. Although bone repair was not completed, sqCS stimulated bone regeneration without BMP-4 and without external mesenchymal cells or preosteoblasts. Therefore, sqCS is a promising substance for promotion of osteogenesis.

Trajectories in the spinal cord and the mediolateral spread in the cerebellar cortex of spinocerebellar fibers from the unilateral lumbosacral enlargement in the chicken.

Spinocerebellar (SC) neurons in the lumbosacral enlargement (LSE) give rise mainly to crossed fibers and generally terminate in parasagittal bands in the granular layer of the chicken cerebellar cortex. However, parasagittal bands for mossy fiber terminals have not always been clear in some cerebellar folia. The present study aimed at (1) observing the course in the spinal cord of the spinocerebellar tracts (SCTs), (2) confirming whether SC fibers originating from the unilateral LSE terminate in parasagittal bands, and (3) elucidating the relationship between the ventral and lateral funicular parts of the SCTs in the cervical enlargement (CE) using anterograde and retrograde labeling methods. The SCTs were located in the medial part of the ventral funiculi in spinal segment (SS) 27, the full width of the ventral funiculi in SS 22, the lateral and ventral funiculi in SS 14 and in the lateral funiculi from SS 10 rostralward. Projection areas in the cerebellar cortex of SC fibers were studied following unilateral injections of WGA-HRP into the LSE. As a result, SC fibers from the LSE terminated bilaterally in parasagittal bands of folia II-VI and IXc. Labeled terminals in the injected side were similar in number to those in the other side in folia II-IV and IXc and more than those in the other side in folia V and VI. Following ablation of the left (contralateral) lateral funiculus of the CE, the same tracer was injected into the right (ipsilateral) LSE or into the anterior or posterior cerebellar lobe. As a result, anterogradely labeled SC fibers passing through the ventral funiculus in the CE mainly terminated in the contralateral cerebellar cortex in folia II, III and IV, and in the ipsilateral cerebellar cortex in folia V, VI and IX. Following ablation of the unilateral lateral funiculus, retrogradely labeled neurons in the contralateral LSE were found in all SC neuron groups showing marked reduction in number. Thus, the ventral and lateral funicular parts of the SCTs in the CE were not pathways for specific SC neuron groups but different in projection areas.

Spatiotemporal distribution of chondroitin sulfate proteoglycans in the developing mouse retina and optic nerve.

The aim of the present study was to determine the distribution of chondroitin sulfate proteoglycans in the mouse retina and optic nerve of the prenatal and postnatal mouse by immunohistochemistry. At embryonic day (E) 18, chondroitin-4-sulfate (C4S), chondroitin-6-sulfate (C6S) and biglycan were detected in the retina and optic nerve. However, aggrecan was seen in the retina but not in the optic nerve. At postnatal day (P) 7, aggrecan and biglycan were clearly observed in the optic nerve, inner nuclear layer and ganglion cell layer and diffuse in the outer retina. C4S diffusely distributed in the retina and optic nerve, but C6S was mainly confined to the photoreceptor layer and optic nerve sheath. At P42, biglycan showed diffuse distribution in the retina and optic nerve with intense staining in nerve-fiber rich layers. Aggrecan showed weak staining at the inner plexiform layer with higher density in the outer and inner nuclear layers, outer plexiform layer and ganglion cell layer. Both C4S and C6S were detected in the optic nerve and retina, but C6S showed strong immunostaining in the photoreceptor layer. The distributions of these proteoglycans with respect of time course during development of the retina and optic nerve suggest that they may have unique or overlapping roles in development and maintenance of the retina and optic nerve.

Expression of small leucine-rich proteoglycans in the developing retina and kainic acid-induced retinopathy in ICR mice.

The aim of this study was to determine the developmental changes of small leucine-rich proteoglycans (PGs), decorin, biglycan and fibromodulin, in ICR mouse retinas and to elucidate their role in the adult retina using kainic acid (KA)-induced retinal degeneration model. Retinas of prenatal, postnatal and adult mice were collected for histological and immunohistochemical staining to investigate the changes in distribution of these PGs. Decorin-and fibromodulin-immunostainings were diffusely distributed at prenatal and early postnatal stages and were stronger in the adult retina. However, biglycan was moderately distributed in the prenatal and early postnatal stages and was faint in the adult retina. Retinas were collected at 1, 3 and 7 days after intravitreal injection of KA. Retinas of KA injected eyes underwent shrinkage accompanied by serious damage in the inner layers. Decorin and fibromodulin were upregulated in the inner retinal layers of KA-injected eyes compared to the normal ones. Our results suggest that decorin and fibromodulin play key roles in retinal differentiation, and contribute to the retinal damage and repair process. However, biglycan may have no or only a limited role in the mouse retinal development or repair process.

Constitution of the ependyma in the chicken telencephalon.

The constitution of ependyma derived from the ventricular zone is different from that derived from other regions of the central nervous system. In the mammalian cerebrum, the ependyma is varied by the regions to cortex or basal ganglia (BG). In the avian telencephalon (Tc), previous studies about the constitution of the ependyma have not revealed clear findings. In the present study, we performed immunostaining of ependymal cells in the chicken Tc to confirm differences in the ependyma of various regions. As a result, 4 patterns of ependyma were defined in the outer side of the lateral ventricle. In the base of the lamina pallio-subpallialis (LPS), ependyma consisted of vimentin/glial fibrillary acidic protein (GFAP) double-positive cells, whereas in the base of the lamina frontalis superior, it consisted primarily of vimentin-positive cells and a small number of vimentin/GFAP double-positive cells. With the exception of the above, the pallial ependyma was a single layer containing vimentin single-positive cells. Lastly, the ependyma of the BG was rich in vimentin single-positive cells. The constitutional differences of the ependyma of the pallium and BG concerned differences in ependymal morphology and cell characteristics. These finding suggest that the bounder between pallium and BG is LPS at the point of ependyma.

Significant Enhancement of Piezoelectric Response in AlN by Yb Addition.

This study employs first-principles calculations to investigate how introducing Yb into aluminum nitride (AlN) leads to a large enhancement in the material's piezoelectric response (d33). The maximum d33 is calculated to be over 100 pC/N, which is 20 times higher than that of AlN. One reason for such a significant improvement in d33 is the elastic-softening effect, which is indicated by a decrease in the elastic constant, C33. The strain sensitivity (du/dε) of the internal parameter, u, is also an important factor for improving the piezoelectric stress constant, e33. On the basis of mixing enthalpy calculations, YbxAl1-xN is predicted to be more stable as a wurtzite phase than as a rock salt phase at composition up to x ≈ 0.7. These results suggest that Yb can be doped into AlN at high concentrations. It was also observed that the dielectric constant, ε33, generally increases with increasing Yb concentrations. However, the electromechanical coupling coefficient, k332, only increases up to x = 0.778, which is likely because of the relatively lower values of ε33 within this range.

Spinocerebellar projections from the cervical and lumbosacral enlargements in the chicken spinal cord.

In birds, spinocerebellar (SC) projections to the cerebellar cortex have not been understood well. We examined SC fiber terminal fields originating from the cervical and lumbosacral enlargements (CE and LSE, respectively) in the chicken. SC fiber terminals show parasagittal bands in the granular layer. Labeled terminals from the CE were distributed primarily in folia II-V and IX. Parasagittal bands of labeled terminals from the CE were not clearly separated in folia II and III but were clearly separated in folia IV and V. In folium IX, labeled terminals were diffusely distributed in all subfolia with no evidence of banding. The numbers of bands were 5 in folium II, 12 in folium III and 7 in folia IV and V at maximum. Labeled terminals from the LSE were distributed primarily in folia II-VI and IX. Labeled terminals from the LSE were arranged in 4 bands in folium II and in 8 bands in folium III at maximum. Parasagittal bands from the LSE in folia IV and V were not clearly separated. In folium VI, the numbers of parasagittal bands was 6 at maximum. In folium IX, labeled terminals were mainly found in subfolium IXc forming 6-8 parasagittal bands. There were more parasagittal bands of labeled terminals from the CE than from the LSE. The topography of SC fiber terminals from the CE was different from that of SC fiber terminals from the LSE.

Relationship between distribution of tapetum fibrosum and retinal pigment epithelium in the sheep eye.

The tapetum lucidum is a light-reflective device improving visual sensitivity in mesopic vision. There have been few studies on tapetal distribution and its relationship with degree of pigmentation in the retinal pigment epithelium (RPE). In the present study, sheep's eyes were used for macroscopical observation of the tapetum, and then histological sections of the posterior eyecups were made to analyze the distribution of tapetal thickness and degree of pigmentation in the RPE. Macroscopically, with available light, the tapetum was located in the dorsal eye fundus to the optic disc and showed an L-shape with the horizontally elongated nasal part and the dorsally expanded temporal part. In photographs with a flash, the tapetal area expanded and showed a more triangular shape. The tapetum histologically consisted of layers of dense collagen fibers and was thicker in the temporal part than in the nasal part. The maximum tapetal thickness was approximately 70 microm. The histological tapetal area was similar to the tapetal shape with a flash light. The pigmentation of the RPE was divided into three types, nonpigmented, transitional, and pigmented areas. The nonpigmented area was similar to the tapetal shape with available light. It is suggested that approximately 55% of the histological tapetal area is covered with the nonpigmented area and is functional under a natural light condition. The functional tapetal area was similar to the L-shaped high-density area of retinal ganglion cells.

Distribution of astroglial lineage cells in developing chicken telencephalon from embryo to young chick.

The largest area of the avian telencephalon (Tc) is the subpallium [basal ganglia (BG)], and the pallium (cortex) is a narrow area located at the surface of the Tc. However, recent studies have proposed that most of the area of the avian Tc is the pallium, which corresponds to the cerebral cortex of mammals. This theory is based on neuronal elements with little regard to glial cells, which play important roles in neurogenesis. In the present study, we observed the distribution of glial cells using immunohistochemistry during maturation and discuss the division of the Tc by glial elements. In the early stage, the distribution and morphology of vimentin-positive radial glial cells were different between dorsal and ventral areas when they began to spread their processes toward the pia matter. During the development stage, vimentin-positive long processes divide the pallium and BG by the lamina pallio-subpallialis. Moreover, the pallium was divided into four regions by vimentin and glial fibrillary acidic protein-positive elements in the later stage.

Polarity Inversion of Aluminum Nitride Thin Films by using Si and MgSi Dopants.

Polarity is among the critical characteristics that could governs the functionality of piezoelectric materials. In this study, the polarity of aluminum nitride (AlN) thin films was inverted from Al-polar to N-polar by doping Si into AlN in the range of 1-15 at.%. Polarity inversion from Al-polar to N-polar also occurred when MgSi was codoped into AlN with Mg to Si ratio was less than 1. However, the polarity can be reversed from N-polar to Al-polar when the ratio of Mg and Si was greater than 1. The effect of Si and MgSi addition was investigated with regards to their crystal structure, lattice parameters, polarity distribution and the oxidation state of each elements. Furthermore, the effect of intermediate layer as well as the presence of point defect (i.e. aluminum vacancy) were investigated and how these factors influence the polarity of the thin films are discussed in this report.

The use of warm fresh whole blood transfusion in the austere setting: A civilian trauma experience.

BACKGROUND: Hemostatic resuscitation strategy using blood components with a balanced ratio is adopted in the civilian trauma setting. However, there is usually limited availability of blood components in the austere setting. Warm fresh whole blood (WFWB) has been used for trauma patients with life-threatening hemorrhage necessitating massive transfusions in the Okinawa Islands, Japan. The purpose of this study was to evaluate the safety and feasibility of WFWB use in the austere civilian trauma setting. METHODS: We conducted a retrospective cohort study between January 1999 and June 2019, including trauma patients who received WFWB within 24 hours of admission. Immediately after WFWB was collected from blood donors, the sample was typed and screened for transmissible infectious diseases. Approximately half of the study population received irradiated WFWB to prevent graft versus host disease. We evaluated the incidence of transfusion-associated adverse events. Transfusion requirements and patient outcomes were compared between early and late WFWB use. RESULTS: A total of 28 patients from three civilian institutions were eligible. Of those, 93% sustained blunt trauma. The median Injury Severity Score was 37 (interquartile range, 32-49). All patients required operative hemostatic intervention, and half of the patients required both operative and endovascular hemostatic interventions. Patients received a median of 1,800 mL WFWB transfusions from seven volunteer blood donors. None of our subjects developed hemolytic reactions, transmissible infectious diseases, or graft versus host disease. Early WFWB use (within 4 hours of admission) was associated with a significant reduction in platelet transfusion requirement compared with the late WFWB group in univariate analysis (16 units vs. 47 units, p = 0.002). CONCLUSION: Warm fresh whole blood use is safe and feasible in an austere civilian trauma setting. Prospective studies with larger cohorts are necessary to determine whether early WFWB use will affect patient outcomes, transfusion requirement, and treatment cost. LEVEL OF EVIDENCE: Therapeutic, Level IV.

Preparation of ZnS/CdSe/ZnS quantum dot quantum well by using a microfluidic reactor.

We have synthesized ZnS/CdSe/ZnS quantum dot quantum well (QDQW) by using a microfluidic reactor. The synthesized QDQW emitted blue fluorescence and the quantum yield was achieved at 50%. Furthermore, we were able to tune the photoluminescence wavelength while maintaining the full width at half maximum (FWHM) by controlling the flow rate in CdSe layer deposition process. Our results demonstrate that high quality CdSe phase was embedded in the ZnS core and shell, and the layer thickness was controlled homogeneously by using the microfluidic system. So, this system is considered as a useful tool for controlling the multilayer nanocrystals such as QDQW.

First-Principles Study of Piezoelectric Properties and Bonding Analysis in (Mg, X, Al)N Solid Solutions (X = Nb, Ti, Zr, Hf).

The enhancement mechanism of piezoelectric properties by codoping Mg + X (X = Nb, Ti, Zr, Hf) into aluminum nitride (AlN) was investigated by first-principles calculations. Theoretically, the piezoelectric constant (d 33) can be increased when the elastic constant (C 33) is decreased and the piezoelectric stress constant (e 33) is increased. All components of e 33, which consists of the clamped e 33, the Born effective charge (Z 33), and the strain sensitivity (du/dε) of the internal parameter, were improved by the addition of Mg + X into AlN. The decrease in C 33 and the increase in du/dε that were observed in Mg + X-codoped AlN indicate the occurrence of elastic softening which was considered to be influenced by changes in the interatomic bond in the wurtzite structure. The bonding analysis of metal-nitrogen (Me-N) pairs in the Mg + X-codoped AlN system which was carried out by crystal orbital Hamilton populations showed that the covalent bonding (Me-N) was weaker than in pure AlN. Therefore, this weaker covalent bond is considered to be one of the origins of the elastic softening. Similar phenomena were also found for Sc-doped AlN which has higher piezoelectric response than that of pure AlN.

Effects of an anti-thyroid drug, methimazole, administration to rat dams on the cerebellar cortex development in their pups.

In the present study, the effects of methimazole (a major anti-thyroid drug) administration to rat dams on the development of cerebellum of their pups were investigated with morphological, morphometrical and functional procedures. A motor performance in the pups was evaluated by a rota-rod test. Brains removed on 6, 9, 12, 15, 25, and 30 postnatal days were analyzed using the sagittal sections of the cerebellum. Results showed that orally administered methimazole to dams produced a congenital hypothyroid model accompanied with an impaired motor coordination assured by the reduced thyroid hormones. The prominent anomaly was found in the internal granular layer in that there were excess bulges or branching and formation of excess sublobules although the normal lobulation pattern was kept. Three dimensional reconstruction imaging revealed the complex morphological pattern of internal granular layer of the cerebellar hemispheres as well as of the vermis, in which bulges and branches were viewed stereoscopically as the smooth ridges rather than irregular or nodal. In addition, the external granular layer in hypothyroidism survived another several days than that in controls. It is suggested that the complex internal granular layer resulted from the overproduced internal granular cells, which originate in the prolonged external granular layer.

Synthesis of CuInS2 fluorescent nanocrystals and enhancement of fluorescence by controlling crystal defect.

For this study, Cu-In-S nanocrystals were developed as a low toxic fluorescent. The stoichiometric CuInS(2) nanocrystals were synthesized facilely by heating a solution of metal complexes and dodecanethiol. The fluorescence would be originated from the crystal defect. We intentionally introduced the crystal defect in nanocrystal with the prospect that the fluorescence intensity would be increased. The defect structure of products was analyzed using Raman spectroscopy and other techniques. The nanocrystals have many defects without phase separation as observed in the bulk material. Consequently, the fluorescence quantum yield achieved approximately 5%. Moreover, the fluorescence quantum yield was increased up to 15% by the ZnS coating.

Functional disorder of the retina in manganese-deficient Japanese quail revealed by electroretinography using a contact lens electrode with built-in light source.

Manganese deficiency results in neurological and skeletal defects, together with ultrastructural disarrangement of the retina in rats. Wild birds show a range of Mn concentrations in their tissues, including the liver, raising the possibility of Mn-related disorders in the wild. Electroretinography (ERG) provides a useful noninvasive approach to evaluate visual function. This method is especially useful in birds, as objective analysis of them is very difficult, while they have well-developed vision. In this study, we carried out a convenient and reliable ERG recording using a contact lens electrode with a built-in light source (LED electrode) of Japanese quail (Coturnix coturnix japonica) fed a Mn-deficient diet. After 10 min light adaptation, single-flash and flicker cone responses were reproducibly recorded to cause an intensity-dependent increase in amplitude of both a-wave and b-wave in single-flash ERG. Mn-deficient feeding markedly decreased the Mn concentration in the liver by almost half in 3 to 6 weeks, followed by body weight loss in 13 to 15 weeks. Implicit time of a-wave and b-wave cone response by single-flash stimulation was significantly delayed in quail with a Mn depletion from 3 to 6 weeks. Every cone response of the Mn-deprived quail had a tendency to decrease amplitude. The ultrastructure of cone photoreceptor cells was disorganized by Mn deficiency, including changes in outer segment discs of photoreceptor cells. These results suggest the essential role of Mn in the integrity of the retinal function of birds.