Fin Formation Research Articles

Trigate FET Device Characteristics Improvement Using a Hydrogen Anneal Process With a Novel Hard Mask Approach

It is reported that hydrogen anneal after fin formation improves the multigate MOSFET Ion/Ioff ratio. However, a higher anneal temperature also results in silicon loss from the fins, thereby reducing the effective width of the device, which results in drive current degradation. This, in turn, offsets the improved mobility-driven drive current gain. A novel hard-mask-based process was developed to retain the trigate fin height after hydrogen anneal. This process demonstrated improved device characteristics for trigate FET devices, particularly for the short-channel devices.

Laminin α5 is essential for the formation of the zebrafish fins

The vertebrate fin fold, the presumptive evolutionary antecedent of the paired fins, consists of two layers of epidermal cells extending dorsally and ventrally over the trunk and tail of the embryo, facilitating swimming during the embryonic and larval stages. Development of the fin fold requires dramatic changes in cell shape and adhesion during early development, but the proteins involved in this process are completely unknown. In a screen of mutants defective in fin fold morphogenesis, we identified a mutant with a severe fin fold defect, which also displays malformed pectoral fins. We find that the cause of the defect is a non-sense mutation in the zebrafish lama5 gene that truncates laminin α5 before the C-terminal laminin LG domains, thereby preventing laminin α5 from interacting with its cell surface receptors. Laminin is mislocalized in this mutant, as are the membrane-associated proteins, actin and β-catenin, that normally form foci within the fin fold. Ultrastructural analysis revealed severe morphological abnormalities and defects in cell–cell adhesion within the epidermis of the developing fin fold at 36 hpf, resulting in an epidermal sheet that can not extend away from the body. Examining the pectoral fins, we find that the lama5 mutant is the first zebrafish mutant identified in which the pectoral fins fail to make the transition from an apical epidermal ridge to an apical fold, a transformation that is essential for pectoral fin morphogenesis. We propose that laminin α5, which is concentrated at the distal ends of the fins, organizes the distal cells of the fin fold and pectoral fins in order to promote the morphogenesis of the epidermis. The lama5 mutant provides novel insight into the role of laminins in the zebrafish epidermis, and the molecular mechanisms driving fin formation in vertebrates.

BMP‐4 and Noggin signaling modulate dorsal fin and somite development in the axolotl trunk

BMP-4, a member of the TGF-beta superfamily of growth factors, is involved in various developmental processes. We investigated the effects of BMP-4 and its antagonist Noggin on axolotl trunk development. Implantation of BMP-4-coated microbeads caused inhibition of muscle and dorsal fin formation in the vicinity of the microbeads. At some distance, myotomes developed with reduced height but increased width, which was accompanied by increased cell proliferation. These effects could be modulated by co-implanting Noggin-coated beads. Immunostaining of Pax7 further revealed that although the dermomyotome was absent in the vicinity of BMP-4-coated beads, at some distance from them, it was thicker than in controls, indicating that moderate amounts of BMP-4 stimulate this layer of undifferentiated cells. In contrast, Noggin generally inhibited the dermomyotome, possibly indicating premature differentiation of dermomyotome cells. We conclude that BMP-4 and Noggin are involved in the regulation of cell proliferation and differentiation during somite development.

Description of larvae and juveniles of <i>Bairdiella ronchus</i> (Sciaenidae: Teleostei) in southeastern Brazil

Developmental stages from flexion larvae to early juvenile of Bairdiella ronchus were described and illustrated from specimens collected along the margins of tidal creeks in the southern zone of the Cananeia-Iguape System on the southeastern coast of Brazil. The B. ronchus larvae were identified working backwards from the juvenile using characteristics common to successively earlier ontogenetic stages. The number of myomeres was 25 (11+14). The flexion of notochord was completed by 5.5 mm SL. The fin formation began in the following sequence: caudal, second dorsal and anal, pelvic fins, first dorsal and pectoral. It was fully completed in this sequence: principal caudal, second dorsal, anal, first dorsal, pelvic and pectoral fins. Squamation began between 10.0 mm SL and 11.1 mm SL, and was entirely completed by 35.0 mm SL. The major head spines included the posterior preocular, supraocular and post-temporal. The larval morphology and pigmentation, mainly the swath pigmentation pattern, were very similar to those described for B. chrysoura in the South Atlantic Bight of the United States. Among sciaenid larvae co-occurring in the study area, Stellifer rastrifer shows larval characteristics more similar to those of B. ronchus, mainly in the preflexion and flexion stages, and in the contraction of the swath pigmentation. They can be differentiated by the fact that in S. rastrifer there is a post-anal lateral pigmentation or caudal pigment on the ventral midline radiating dorsally, which is absent in B. ronchus.

Formation of integral fins function-surface by extrusion-ploughing process

An extrusion-ploughing process was presented to fabricate the integral fin function-surface. Cutting edge inclination angle and rake angle can be calculated from the tool's geometry relationship. The description of fins' geometry characters was standardized. The experiments show that, when the middle cutting edge's inclination angle η is less than 35°, continuous fin will come out; when η is between 35° and 55°, the fins will be saw-tooth ones, and the fins will be torn when this angle is above 55°; when the extrusion angle θ is between 60° and 150°, the fins will appear, or else, the fins will be torn into chips from the base. Forming angle and clearance angle have little effect on fin's formation. For continuous fin, its height is close to cutting depth when it is small, but it will become approximately constant as cutting depth grows; for saw-tooth fins, the width, the height, as well as the clearance will increase with the increase of cutting depth, but the increment of clearance is small; neither for continuous fin, nor for saw-tooth ones, cutting velocity has little influence on their structure parameters.

Inhibition of oral–facial clefting gene Interferon Regulatory Factor 6 disrupts gastrulation, pectoral fin formation, and somite boundary formation in zebrafish

Inhibition of oral–facial clefting gene Interferon Regulatory Factor 6 disrupts gastrulation, pectoral fin formation, and somite boundary formation in zebrafish

Cracks and fins in sulfate sand: Evidence for recent mineral-atmospheric water cycling in Meridiani Planum outcrops?

Research Article| April 01, 2006 Cracks and fins in sulfate sand: Evidence for recent mineral-atmospheric water cycling in Meridiani Planum outcrops? Gregory V. Chavdarian; Gregory V. Chavdarian 1Geology Department, University of California–Davis, Davis, California 95616, USA Search for other works by this author on: GSW Google Scholar Dawn Y. Sumner Dawn Y. Sumner 1Geology Department, University of California–Davis, Davis, California 95616, USA Search for other works by this author on: GSW Google Scholar Geology (2006) 34 (4): 229–232. https://doi.org/10.1130/G22101.1 Article history received: 08 Aug 2005 rev-recd: 20 Nov 2005 accepted: 22 Nov 2005 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Gregory V. Chavdarian, Dawn Y. Sumner; Cracks and fins in sulfate sand: Evidence for recent mineral-atmospheric water cycling in Meridiani Planum outcrops?. Geology 2006;; 34 (4): 229–232. doi: https://doi.org/10.1130/G22101.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Gypsum dunes at White Sands National Monument, New Mexico, provide an excellent analog to sulfate-rich eolian outcrops on Meridiani Planum, Mars, as characterized by the Rover Opportunity. Numerous outcrops imaged by Opportunity contain polygonal cracks that crosscut bedding and extend across most surfaces of boulders. Some of these cracks are associated with millimeter-thick platy fins that protrude as much as a few centimeters above outcrops. Similar cracks crosscut bedding at White Sands on erosional stoss slopes and in pedestals of cemented dune sand. The cracks at White Sands form in response to cementation of damp gypsum sand followed by contraction due to dehydration. During warm seasons, cracked sand is dry and cracks rarely grow, although some may form after rainstorms. Two types of fins form along cracks and differentially eroded laminae. White fins represent subsurface differential cementation along cracks followed by differential erosion. Tan fins form due to cementation of crack edges and laminae on exposed dune surfaces. Wind-blown sediment adheres to damp tan fins. Similar processes may be important for crack and fin formation in Meridiani Planum outcrops, implying recent water cycling between sulfate outcrops and the Martian atmosphere. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

The establishment and analysis of fin formation model during ploughing process

Owing to the present more stringent exhaust emission regulations, it becomes increasingly significant that the 3D fins on the surface of stainless steel strip used as the metal carrier of a catalytic converter is machined to improve substantially the effectiveness of the converter. Thus in this work, the mechanism of pre-roll ploughing on the surface of stainless steel strip was studied systematically, and especially the process and conditions of 3D fin formation were analyzed. Further, the proper mathematical model was established. Based on the volume of fin ploughed out being equal to the volume of the metal extruded up by the extruding face of the tool, the relation of the fin height, the distance of interval tools and the ploughing depth has been achieved. The distance of the interval of the tools has a great effect on fin height: with the increase of the distance of interval of the tools, the fin height gradually decreases. With the increase of ploughing depth (equal to groove depth), the fin height becomes larger. The theoretical analyses basically accords with experimental results. The conversion rate of a catalytic converter using a fin metal carrier is 12–15% higher than that of a catalytic converter using a smooth metal carrier of identical volume.

Early ontogeny of coal grunter from hormone-induced spawnings and laboratory-reared embryos and larvae

Spawning of coal grunter Hephaestus carbo was successfully induced using doses of human chorionic gonadotrophin (hCG) between 500 and 3000 IU kg (body weight)−1. Water hardened eggs are telolecithal, amber in colour, spherical, transparent, demersal and slightly adhesive with a single large oil droplet and perivitelline space 47% of total egg volume. Cleavage begins 10–15 min after fertilization. Epiboly begins 6h after fertilization and continues for 4 h. Invagination of the neural tube is apparent 11·5 h after fertilization, followed by progressive organogenesis up to hatching 60–80 h after fertilization. An invagination in the yolk, consistent in shape, position and time of appearance among embryos spawned from numerous brood stock pairs, was visible in all fertilized eggs between neurulation (11-5 h) and early organogenesis (20 h). The functional significance of this yolk invagination is unknown. Newly-hatched larvae (4·2 mm LT) are elongate and possess well developed eyes, a functional mouth, and a large yolk sac. Yolk is fully resorbed and first feeding occurs at 6 days posthatching. The sequence of fin formation is caudal, second dorsal and anal, first dorsal, pectoral and pelvic. The prefiexion larval stage lasts for c.8 days and flexion of the notochord is complete within a further 8–9 days. Squamation commences at 30 days posthatching and transition to the juvenile life stage is complete by 35–40 days posthatching.

Early ontogeny of coal grunter from hormone‐induced spawnings and laboratory‐reared embryos and larvae

Spawning of coal grunter Hephaestus carbo was successfully induced using doses of human chorionic gonadotrophin (hCG) between 500 and 3000 IU kg (body weight)−1. Water hardened eggs are telolecithal, amber in colour, spherical, transparent, demersal and slightly adhesive with a single large oil droplet and perivitelline space 47% of total egg volume. Cleavage begins 10–15 min after fertilization. Epiboly begins 6h after fertilization and continues for 4 h. Invagination of the neural tube is apparent 11·5 h after fertilization, followed by progressive organogenesis up to hatching 60–80 h after fertilization. An invagination in the yolk, consistent in shape, position and time of appearance among embryos spawned from numerous brood stock pairs, was visible in all fertilized eggs between neurulation (11‐5 h) and early organogenesis (20 h). The functional significance of this yolk invagination is unknown. Newly‐hatched larvae (4·2 mm LT) are elongate and possess well developed eyes, a functional mouth, and a large yolk sac. Yolk is fully resorbed and first feeding occurs at 6 days posthatching. The sequence of fin formation is caudal, second dorsal and anal, first dorsal, pectoral and pelvic. The prefiexion larval stage lasts for c.8 days and flexion of the notochord is complete within a further 8–9 days. Squamation commences at 30 days posthatching and transition to the juvenile life stage is complete by 35–40 days posthatching.

Reproductive biology, early life-history and settlement distribution of sand flathead (Platycephalus bassensis) in Tasmania

The life-history ecology of P. bassensis was examined to determine the spatial and temporal patterns of spawning, larval transport and settlement distribution in coastal and continental shelf waters of southern and eastern Tasmania. Larval development is characterized by a large size at flexion and pelvic and dorsal fin formation, lightly pigmented trunk and tail and the absence of strong teeth on the roof of the mouth or lower jaw. The distribution of spawning fish and larvae and patterns of hydrography indicate that spawning occurs throughout estuaries, coastal embayments and inshore shelf waters of southern and eastern Tasmania. Larvae are concentrated in mid waters, which retain larvae inshore because cross-shelf subsurface currents are predominantly onshore. Spawning in P. bassensis occurred for up to six months between October and March. The broad range of lengths of 0+ fish in every month indicates that settlement occurred over an extended period, reflecting the protracted spawning period. Juveniles showed a preference for unvegetated habitats in nearshore waters, compared with beds of the seagrass Heterozostera tasmanica. Size compositions of 0+ fish indicate the presence of several cohorts in most months;this is discussed in terms of early life-history strategy and availability of settlement habitats.

Egg and larval development of laboratory‐reared striped trumpeter latris lineata (forster in bloch and schneider 1801) (percoidei: Latridiidae) from Tasmanian waters

Description of striped trumpeter (Latris lineata (Forster in Bloch and Schneider 1801)) eggs and larvae, previously described in summary only, is provided and illustrated from laboratory‐reared material. Laboratory fertilised eggs are round, 1.26–1.44 mm diameter, with a single, pigmented oil globule 0.27–0.29 mm diameter in an unsegmented yolk. Early‐stage embryos are pigmented on trunk and tail dorso‐laterally, forming a dorsal and ventral pigment band in late‐stage embryos. Hatching occurs 7–8 days post‐fertilisation in 12°C. Larvae are 2.8–3.5 mm body length (BL) at hatching with a voluminous finfold, large yolk sac with centrally‐placed oil globule, distinct pigmentation pattern, and no head spines. Flexion occurs from 5.6 to 8.7 mm BL. Fin formation commences from 6.6 mm BL in the sequence caudal, dorsal and anal (simultaneously), pectorals and pelvics. Myomeres number 33–39. Larvae are pigmented predominantly on the head, dorsal and ventral surfaces of trunk and tail, and gut ventrally, with melanophores also on upper and lower jaws. Larvae survived to 45 days post‐fertilisation, 11.9 mm BL, with complete fin‐formation of the caudal fin only. Similarities are noted between L. lineata larvae and aplodactylid, bovichtid, cheilo‐dactylid, chironemid, sillaginid, and tetragonurid larvae. A small number of L. lineata larvae were also caught inshore and at shelf edge on the Tasmanian west coast in late winter/early spring (September/ October).

Genetic analysis of fin formation in the zebrafish, Danio rerio.

In the zebrafish, Danio rerio, a caudal and pectoral fin fold develop during embryogenesis. At larval stages the caudal fin fold is replaced by four different fins, the unpaired anal, dorsal and tail fins. In addition the paired pelvic fins are formed. We have identified a total of 118 mutations affecting larval fin formation. Mutations in 11 genes lead to abnormal morphology or degeneration of both caudal and pectoral fin folds. Most mutants survive to adulthood and form a surprisingly normal complement of adult fins. Mutations in nine genes result in an increased or reduced size of the pectoral fins. Interestingly, in mutants of one of these genes, dackel (dak), pectoral fin buds form initially, but later the fin epithelium fails to expand. Expression of sonic hedgehog mRNA in the posterior mesenchyme of the pectoral fin bud is initiated in dak embryos, but not maintained. Mutations in five other genes affect adult fin but not larval fin development. Two mutants, longfin (lof) and another longfin (alf) have generally longer fins. Stein und bein (sub) has reduced dorsal and pelvic fins, whereas finless (fls) and wanda (wan) mutants affect all adult fins. Finally, mutations in four genes causing defects in embryonic skin formation will be briefly reported.

Mutations affecting pigmentation and shape of the adult zebrafish

Mutations causing a visible phenotype in the adult serve as valuable visible genetic markers in multicellular genetic model organisms such as Drosophila melanogaster, Caenorhabditis elegans and Arabidopsis thaliana. In a large scale screen for mutations affecting early development of the zebrafish, we identified a number of mutations that are homozygous viable or semiviable. Here we describe viable mutations which produce visible phenotypes in the adult fish. These predominantly affect the fins and pigmentation, but also the eyes and body length of the adult. A number of dominant mutations caused visible phenotypes in the adult fish. Mutations in three genes, long fin, another long fin and wanda affected fin formation in the adult. Four mutations were found to cause a dominant reduction of the overall body length in the adult. The adult pigment pattern was found to be changed by dominant mutations in wanda, asterix, obelix, leopard, salz and pfeffer. Among the recessive mutations producing visible phenotypes in the homozygous adult, a group of mutations that failed to produce melanin was assayed for tyrosinase activity. Mutations in sandy produced embryos that failed to express tyrosinase activity. These are potentially useful for using tyrosinase as a marker for the generation of transgenic lines of zebrafish.

Probing the functions of endogenous lectins: Effects of a monoclonal antibody against the neural crest‐stage lectin of Xenopus laevis on trunk development

Trunk neural crest of Xenopus laevis has been confronted prior to migration with whole or fragments of a monoclonal antibody raised against the carbohydrate-binding site of the endogenous neural crest-stage galactoside binding lectin (Milos et al.: Anat. Embryol., 182:319-327 '90). External fin formation was inhibited in confronted regions but extensive internal matrix develops suggesting interiorization of fin tissue. In the regions of missing fin, the myotomes overgrew the neural tube and dorsal root ganglion neuronal numbers became more variable. Melanophore numbers in regions of missing fin did not change but a significantly greater proportion of the pigment cells localized on the muscle surface that had overgrown the neural tube suggesting that the pigment cell population redistributed itself to occupy a greater myotomal area.

Recent advances in primary palate and midface morphogenesis research.

During the sixth week of human development, the primary palate develops as facial prominences enlarge around the nasal pits to form the premaxillary region. Growth of craniofacial components changes facial morphology and affects the extent of contact between the facial prominences. Our recent studies have focused on developing methods to analyze growth of the primary palate and the craniofacial complex to define morphological phases of normal development and to determine alterations leading to cleft lip malformation. Analysis of human embryos in the Carnegie Embryology Collection and mouse embryos of cleft lip and noncleft strains showed that human and mouse embryos have similar phases of primary palate development: first, an epithelial seam, the nasal fin, forms; then a mesenchymal bridge develops through the nasal fin and enlarges rapidly. A robust mesenchymal bridge must form between the facial prominences before advancing midfacial growth patterns tend to separate the facial components as the medial nasal region narrows and elongates, the nasal pits narrow, and the primary choanae (posterior nares) open posterior to the primary palate. In mouse strains with cleft lip gene, maxillary growth, nasal fin formation, and mesenchymal replacement of the nasal fin were all delayed compared with noncleft strains of mice. Successful primary palate formation involves a sequence of local cellular events that are closely timed with spatial changes associated with craniofacial growth that must occur within a critical developmental period.

Glutathione effects Ciona intestinalis larval tunic morphogenesis

AbstractDechorionated neurulae and early tail‐bud embryos of Ciona intestinalis (Linnaeus) develop into tadpole larvae without fully formed dorsal, ventral, or caudal fins, although other aspects of organ and tissue development appear normal. Groups of dechorionated neurulae treated with the reducing agent glutathione exhibit a 5‐8% enhancement in caudal fin length compared with dechorionated controls. Other reducing substances tested, namely, gallic acid, chlorogenic acid, cysteine, and dithiothreitol, had no effect on fin formation, possibly due either to their rapid oxidation in aerated seawater (chlorogenic and gallic acids) or to kinetic inertness (dithiothreitol and cysteine). These results imply that larval fin morphogenesis requires secretion of a specific reducing substance.

Morphological and behavioural development of halibut, Hippoglossus hippoglossus (L.) larvae

Live yolk‐sac halibut, Hippoglossus hippoglossus (L.) larvae from rearing experiments at Austevoll Aquaculture Station, Norway, were examined from hatching to past first feeding for developmental morphology and behaviour. The findings include development of the respiratory and circulatory organs, eye pigmentation, mouth formation, organs of the digestive system and the process of yolk absorption, as well as swimming speed and activity levels.A stomodeum is not present at hatching although drinking is possible through a pair of branchial pits which gradually develop into the operculum and gill basket. The mouth normally opens slowly, the gape being restricted by a transverse septum until bones are formed. The amount of time spent swimming varies from less than 15% of the observation period during the first 2 weeks after hatching to between 70 and 100% around the seventh week after hatching, when individual differences become more apparent. Larvae generally react with a burst of swimming when two come into contact. Speed and duration of swimming seems to be correlated with development of eye pigment, heart size and fin formation. The yolk‐sac period is divided into four stages.

Morphological observations in normal primary palate and cleft lip embryos in the Kyoto collection

Normal developmental events during human primary palate formation and alterations associated with cleft lip remain poorly defined. The purpose of this study was to analyze serially sectioned human embryos to identify morphological changes during normal palatal closure and alterations associated with failure of palatal formation. Normal and cleft embryos from the histological collection at the Congenital Anomaly Research Center at the University of Kyoto were studied and photographed for detailed evaluation. Seven serially sectioned cleft lip embryos of stages shortly after primary palate formation (Streeter-O'Rahilly stages 19, 20, and 22) with unilateral or bilateral clefts with varying degrees of clefting were studied. In the normal Kyoto embryos, initial nasal fin (epithelial seam) formation was observed between the medial nasal process and the lateral nasal and maxillary processes at stage 17. During stages 18 and 19, the nasal fin epithelium was replaced by an enlarging mesenchymal bridge, as the maxillary processes united with the medial nasal processes to form the primary palate. The most prominent features observed in the cleft embryos were a reduced thickness of mesenchymal bridging between the medial nasal and maxillary processes, with an excessive amount of epithelium at the junctions between these processes. With ingrowth of the maxillary processes, greater cell dispersion and apparent extracellular matrix accumulation were observed in the medial nasal region. During closure of the primary palate, terminal branches of the maxillary nerve crossed the mesenchymal bridge to the medial nasal region. The partial clefts had reduced maxillary ingrowth and smaller union areas with the medial nasal process. Detailed studies of experimental animal models are required to identify regional growth required for contact between the facial prominences, to clarify the mechanisms of mesenchymal ingrowth and epithelial displacement during palatal formation, and to identify local and/or general factors causing alterations that lead to primary palatal clefting.

Using Home Observation in the Clinical Assessment of Children

Our clinical experiences in a pediatric setting indicate that selective use of home observational assessment can facilitate psychological evaluation of such problems as failure to thrive, behavioral and developmental deficits, and dysfunctional adaptation to childhood chronic illness. Home observations provide a valuable source o fin formation about parent-child and family interaction patterns, which enhances clinical understanding and family acceptance of intervention plans. We discuss the considerable technical difficulties involved in the conduct and interpretation of information from home visits. Home observational assessment is especially useful in planning intervention for families that are difficult to reach and in sensitizing clinicians to the role o f family interaction and culture in children's behavioral problems.