Double Branch Research Articles

Effects of the Yellow Sea Warm Current on the winter temperature distribution in a numerical model

The temperature distribution and circulation patterns in the Yellow Sea (YS) are examined by using a wave‐tide‐circulation coupled numerical model. This model sufficiently reproduces the variation of the warm tongue structure of the Yellow Sea Warm Current (YSWC) from the double branches flowing along the YS Trough and the western 60 m isobath in January to the single stream along the western temperature front in March. This is observed in both the long‐term monthly climatology and the satellite‐based sea surface temperature images in recent years. Examining the local heat balance in the numerical model during the entire cooling period, it is found that the YSWC has a very important influence on the YS warm tongue structure. Compared with the surface cooling, the influence of the advection is small in the coastal shallow area but large in the deep warm tongue area (up to 50% of the magnitude of heat flux). Although bathymetry is the essential factor which causes the temperature front, the YSWC is the key factor which positions, shapes, and maintains the warm tongue structure. This helps to affirm the existence of the YSWC, at least as a monthly mean flow. However, more high‐resolution current observations in deeper layers west of Cheju Island and the western fork of the YS Trough are needed to confirm the existence of the YSWC and its characteristic timescale in the real YS.

Anatomy of the superficial temporal artery and its branches: its importance for surgery

The temporoparietal, parieto-occipital flaps or the forehead flaps that are used in reconstructive surgery are prepared on the superficial temporal artery (STA) and its branches. For a successful surgery and a suitable flap design, adequate anatomical knowledge is needed. In our study, the red colored latex solution was injected into the external carotid artery; the STA and its branches were dissected in 27 specimens. The mean diameter of the STA at the zygomatic arch was determined as 2.73+/-0.51 mm. The diameters of the frontal branch were bigger than those of the parietal branch in 15 samples out of 27. The diameters of both the frontal and parietal branches were equal in four samples. The diameter of the parietal branch was bigger than that of the frontal branch in eight samples. In 20 samples out of 27 (74.07%), the bifurcation point of the STA was above the arch. In six samples (22.22%), the STA bifurcated directly over the arch. In only one sample (3.70%), bifurcation was not observed and the STA continued only as a frontal branch (absence of the parietal branch). The absence of the frontal branch was not encountered. In one sample (3.70%), double parietal branches were observed. In six samples out of 27 (22.22%), zygomatico-orbital artery was not encountered. In 21 samples (77.77%), zygomatico-orbital arteries ran towards the face, parallel to zygomatic arch and distributed in the orbicularis oculi muscle. The transverse facial artery existed in all samples. The auricular branches running to the helix and tragus were observed in all samples. The STA was 16.68+/-0.35 mm at the front of the tragus. Some landmarks were chosen on the head and then the STA was observed where it crossed all of these landmarks. This paper confirms the well-known variability of the superficial temporal arterial branches and their relation to the pericranial region. Knowledge concerning the arterial features of the lateral forehead region is important for the aesthetic surgeon. STA and its branches have been found to be suitable for use in microvascular anastomoses. A better understanding of the midline forehead vascularity should allow modification of reconstructive techniques and reduce postoperative complications.

3709 直角二連分岐枝管内における振動発生現象の実験的解析(J13-1 流動励起振動1(管内流れによる振動),J13 流体関連の騒音と振動)

3709 直角二連分岐枝管内における振動発生現象の実験的解析(J13-1 流動励起振動1(管内流れによる振動),J13 流体関連の騒音と振動)

Different behaviour of a double branch-and-bound algorithm on [formula omitted] and [formula omitted] problems

In this paper we face the permutation flow-shop scheduling problem with a makespan objective function in two variants, with and without storage space between machines. We use an improved branch and bound algorithm, suitable for parallel computation, to solve these problems, and auxiliary heuristics to attain an initial good solution. The auxiliary heuristics proposed are built by two steps: in the first step a permutation is obtained; in the second step a local search procedure is applied. The improvement obtained by the local search procedure on NEH heuristic as first step is shown. Since the flow-shop scheduling problem with storage space is a relaxation of the problem without storage space, some elements and procedures developed for that problem can be used in both problems. In particular, some bounding procedures, for instance Nabeshima or Lageweg bounding schema, can be adapted. Moreover, the reversibility property holds on both problems. Consequently a double branch and bound algorithm can be applied simultaneously to the direct and the inverse instances. The same sets of data are submitted to heuristics and to the double branch-and-bound algorithm, LOMPEN, assuming first they are instances of flow-shop scheduling problem with storage space and later they are instances of flow-shop scheduling problem without storage space. The algorithms are coded in a similar way; therefore the behaviour and performance can be compared.

Zonal structure of zooplankton communities in the Southern Ocean South of Australia: results from a 2150 km continuous plankton recorder transect

The Southern Ocean south of Australia is oceanographically complex, being characterized by double branches of the Sub-Antarctic Front (SAF), Polar Front (PF) and Southern Antarctic Circumpolar Current (SACCF), in addition to the Southern Boundary (SB) of the ACC. From 25 February to 3 March 2002 a 2150-km Continuous Plankton Recorder (CPR) transect was conducted along 140 °E, between 47.02 °S and 66.36 °S, crossing each of these frontal zones. Surface temperature, salinity, and fluorescence were measured at 1-min intervals in conjunction with CPR samples. Additional physical data for the region south of 61 oS was provided by nine CTD stations. Multivariate and Indicator Species analysis of the high resolution (∼9.2 km) zooplankton samples identified six distinct assemblages which were strongly correlated with frontal/oceanographic zones. These assemblages appeared to be structured by a combination of zonal differences in water mass structure, phytoplankton regimes, and small scale intra-zonal features (e.g. eddies). The northern branch of the SAF was the strongest biogeographic boundary, separating a high proportion of sub-tropical and temperate species from the waters to its south. The study area differed from other sectors of the Southern Ocean in that the northern PF, equivalent to the PF in other sectors, was not a zone of distinct ecological transition. Two of the identified assemblages were located with the seasonal ice zone, south of the northern SACCF. Although Euphausia superba larvae were a component of both of these assemblages, this species, together with appendicularia, was most abundant south of the SB. The seasonal ice zone north of the SB was dominated by small copepods ( Oithona similis and Ctenocalanus citer), appendicularia and foraminifera. Although the physical characteristics of the frontal zones can be subtle, the demarcation between zooplankton assemblages was clear. Cross-frontal changes in zooplankton assemblages highlight their role in long-term monitoring programs as indicators of environmental change.

Design of double-sampling /spl Sigma//spl Delta/ modulation A/D converters with bilinear integrators

Double-sampling techniques allow to double the sampling frequency of a switched capacitor /spl Sigma//spl Delta/ analog-to-digital convertors without increasing the clock frequency. Unfortunately, path mismatch between the double sampling branches may cause noise folding, which could ruin the modulator's performance. The fully floating double-sampling integrator is an interesting building block to be used in such a double sampling /spl Sigma//spl Delta/ modulator because its operation is tolerant to path mismatch. However, this circuit exhibits an undesired bilinear filter effect. This effectively increases the order of the modulator by one. Due to this, previously presented structures don't have enough freedom to fully control the modulator pole positions. In this paper, we introduce modified topologies for double-sampling /spl Sigma//spl Delta/ modulators built with bilinear integrators. We show that these architectures provide full control of the modulator pole positions and hence can be used to implement any noise transfer function. Additionally, analytical expressions are obtained for the residual folded noise.

Distal variations of the neurovascular pedicle of the serratus anterior muscle as a flap

The serratus anterior muscle has recently been suggested as a versatile and reliable flap for reconstruction of complex craniofacial and neck lesions, extremity and sacroiliac region injuries, as well as intrathoracic and extrathoracic reconstruction procedures. The muscle has been used as a microvascular flap or a pedicled transfer and has been transferred in combination with other muscles, bones, and skin. We performed 15 dissections of adult axilla regions that were examined under x3.5 loupe magnification to collect anatomic data regarding the neurovascular pedicle of the serratus anterior muscle. The serratus muscle and fascia were found to have a dual blood supply, with the upper part supplied by the lateral thoracic artery and the lower part by terminal branches of the thoracodorsal artery. The lateral thoracic artery was noted to supply the upper four slips but it extended into the lower serratus anterior muscle in two cases. Seven branching patterns were found in the lower serratus anterior muscle. In type I, the only branch of serrati proceeded over the long thoracic nerve. Type II had the only branch of serrati proceeding under the long thoracic nerve. In type III, double branches of serrati proceeded over the long thoracic nerve; while in type IV branches of serrati ran with a double branch under the long thoracic nerve. In type V, three serrati branches proceeded over the long thoracic nerve. Type VI serrati branches were branches of thoracodorsalis, which was hypoplastic, and the supply was maintained from the lateral thoracic artery. In type VII, one serrati branch ran over the long thoracic nerve. There was no connection between the branches of serrati and the branches of the lateral thoracic artery. The length of the long thoracic nerve, the number of motor axons and the vascular network in anatomic proximity to this nerve make it an expendable but powerful source of reconstructions of head, neck, chest wall and extremity defects. Results of this study provide an anatomic framework to improve current reconstructive or aesthetic procedures on the serratus anterior neurovascular structures.

Time dependence of directive channelling in photonic crystal based multiport devices

Time dependence of directive routing of an optical wave in an add-drop multiplexer is theoretically studied using finite difference time domain (FDTD) methods. The device under investigation is a double branch waveguide coupler patterned in a two-dimensional photonic crystal. The latter is constituted by a two-dimensional array of air holes deeply etched in the growth direction of a InP-based semiconductor heterostructure which ensures the lateral confinement of light. Sub-picosecond transfer times and picosecond switching times between coupled channels are demonstrated around 1.55 μm and various operating modes (dropping, three-color operation) are detailed.

Is the external laryngeal nerve an exclusively motor nerve? The cricothyroid connection branch.

To obtain an accurate morphological description of the nerve that provides communication between the external laryngeal nerve and the recurrent laryngeal nerve in a large sample of human larynges. Morphological study of human larynges. Microdissection of 103 human larynges obtained from necropsies was performed. Both the external laryngeal nerve and the recurrent laryngeal nerve were identified and dissected. The existence of a communication between the two nerves was evaluated. A neural communication between the external laryngeal nerve and the recurrent laryngeal nerve was found in 85% of the larynges studied (bilaterally in 44% and unilaterally in 41%). Two patterns of communication (with single or double branches) were found. The communication between the nerves can appear at different levels, giving off collateral branches to the cricothyroid muscle (23%), the cricothyroid joint capsule (49%), and the subglottic mucosa (50%). The nerve supply of the human larynx is more complex than classically considered. Our study does not support the classic neuroanatomical belief that the external laryngeal nerve is purely a motor nerve to the cricothyroid muscle. Our results reveal that it carries sensory and motor fibers on to other muscles (thyroarytenoid) or regions (subglottis mucosa and cricothyroid joint), as has been demonstrated in experimental studies in cats and dogs.

Synthesis of branched polymers by means of anionic polymerization. 11. anionic synthesis of densely branched polystyrenes carrying double branches in each repeating unit

AbstractWe have demonstrated the first successful synthesis of well‐defined densely branched polystyrenes carrying double branches in each of all repeating unit of backbone polymer by the coupling reaction of 1,1‐diphenylethylene‐end‐capped polystyryllithiums with novel polystyrene derivatives having two benzyl bromide moieties in each monomer unit. The coupling reaction efficiently and quantitatively proceeded without any steric limitations to introduce two polystyrene branches in each repeating unit under certain conditions in THF at −40°C. Thus, a series of 36.4‐ and 181‐arm densely branched polystyrenes were synthesized (Mw = 365 ∼ 2 000 kg/mol, Mw/Mn = 1.01 ∼ 1.03). In the 36.4‐arm branched polystyrenes thus synthesized, the maximum Mw value of the introduced polystyrene as a branch segment was 55.1 kg/mol. The experimental g‘ values of the 36.4‐arm branched polystyrenes deterimined in the range of 0.14 ∼ 0.15 were very close to the value of 0.13 calculated from the empirical equation previously reported by Roovers.

Resistência ao fluxo de gases através das cânulas de intubação de dupla luz

JUSTIFICATIVA E OBJETIVOS: As cânulas de dupla luz podem impor resistências distintas ao fluxo. Esta disparidade pode acarretar ventilação pulmonar não homogênea. O objetivo deste trabalho é comparar o padrão resistivo da cânula de intubação de dupla luz 37 FR com o das cânulas convencionais, utilizadas em nosso meio, quando submetidas a fluxos diferentes. MÉTODO: Foram utilizadas cânulas de intubação orotraqueal com diâmetros internos de 7, 7,5, 8 e 8,5 mm e de dupla luz 37 FR. Os fluxos foram gerados e mantidos por aparelho de anestesia. A pressão resistiva gerada nas cânulas foi aferida por um pneumotacógrafo de orifício variável e convertida para sistema digital. As resistências foram obtidas dividindo-se as pressões medidas pelos fluxos empregados. Os dados foram submetidos à análise de variância (ANOVA) e comparados pelo teste de Tukey. RESULTADOS: Foram registradas cinco medidas obtidas aleatoriamente. Todas as cânulas estavam abertas para o meio-ambiente. Resistências estão em cmH2O.L-1.s-1. A resistência aumenta de forma linear com elevação do fluxo. A cânula 37 FR dupla luz mostrou padrão resistivo semelhante ao da cânula com diâmetro interno de 7,5 mm. A oclusão dos ramos da sonda 37 FR eleva significativamente a resistência ao fluxo. Os fluxos de 0,1 a 0,2 L.s-1 resultaram em pressões resistivas semelhantes para uma mesma sonda de intubação, exceto para cânula 7 mm ou para a 37 FR com oclusão (p < 0,001). CONCLUSÕES: Os padrões resistivos da cânulas 37 FR e 7,5 mm mostraram-se bastante próximos. A oclusão de algum ramo da sonda de dupla luz eleva significativamente a resistência, mas de modo indistinto entre ambos ramos para fluxos abaixo de 0,5 L.s-1. Os resultados do presente estudo sugerem a redução de fluxos inspiratórios como parâmetro para diminuir a resistência do sistema de ventilação, quando um dos lumens de um tubo de dupla luz for obstruído.

Influence of molecular structure on the properties of confined fluids by molecular dynamics simulation

We recently developed a new molecular dynamics (MD) simulation approach for studying fluids confined between two solid substrates and in equilibrium with bulk fluids. Using this method, we perform MD simulations to investigate the influence of molecular structure on the properties of confined Lennard–Jones (LJ), n-decane, and 2,2-dimethyloctane fluids. Under confinement, spherical LJ particles and linear n-decane form layers parallel to the surfaces, while asymmetric 2,2-dimethyloctane forms a ‘pillared–layered’ structure consisting of both parallel and perpendicular molecules. As surface separation is varied, the number of spherical LJ and symmetric n-decane molecules changes in a step-wise manner, while the number of 2,2-methyloctane molecules varies in a smooth fashion due to pillar molecules gradually switching between parallel and perpendicular orientations. Concomitant configurational transitions cause oscillatory solvation forces, with force maxima corresponding to well-layered configurations. The double branches in 2,2-dimethyloctane reduce the densities and structural changes in the layers adjacent to the surfaces, causing solvation forces and force oscillations to be less pronounced than those of linear chains. Concerning dynamical properties, the translational diffusivity, computed with Einstein relation, and the shear viscosity, computed with Green–Kubo method, both oscillate, the former out of phase and the latter in phase with respect to force oscillations. Better-ordered films having higher densities exhibit lower translational diffusivities but higher shear viscosities. At disordered states, bulk diffusivities and viscosities are recovered. Asymmetric, branched 2,2-dimethyloctane has lower diffusivities due to its bulky t-butyl group, and weaker diffusivity and viscosity oscillations due to its reduced ordering and configurational differences.

The Topological Interpretation of the Core Group of a Surface inS4

AbstractWe give a topological interpretation of the core group invariant of a surface embedded inS4[F-R], [Ro]. We show that the group is isomorphic to the free product of the fundamental group of the double branch cover ofS4with the surface as a branched set, and the infinite cyclic group. We present a generalization for unoriented surfaces, for other cyclic branched covers, and other codimension two embeddings of manifolds in spheres.

Multiple stellar populations in the Sextans dwarf spheroidal galaxy?

AbstractWe present wide-field multiband (BVI) CCD photometry (down to of the very low surface brightness dwarf spheroidal galaxy Sextans. In the derived colour–magnitude diagrams we find evidence suggesting the presence of multiple stellar populations in this dwarf spheroidal. In particular, we discover (i) a blue horizontal branch tail that appears to lie on a brighter sequence with respect to the prominent red horizontal branch and the RR Lyrae stars, very similar to what was found by Majewski et al. for the Sculptor dwarf spheroidal, (ii) hints of a bimodal distribution in colour of the red giant branch stars, (iii) a double red giant branch bump. All of these features suggest that (at least) two components are present in the old stellar population of this galaxy: the main one with and a minor component around . The similarity to the Sculptor case may indicate that multiple star formation episodes are also common in the most nearby dwarf spheroidals that ceased their star formation activity at very early epochs.

A many-bodyapproach to spin-wave excitations in itinerant magnetic systems

Using a recently developed Green's function formalism, we havecalculated the spin-wave spectra and dispersions in Ni and Fe. ForNi(100), the dispersion exhibits two branches as observedexperimentally. The calculated higher optical branch is found to betoo high in energy when the standard local density approximationband-structure is used but a very good agreement with the measureddispersion is obtained when the exchange splitting is reduced, tocorrespond to the experimental value of the exchange splitting.We also found a double branch along Ni(111) which is not observedexperimentally. For Fe, the calculated dispersion surprisinglyexposes a gap midway along Γ-N in disagreement withexperimental data. However, an analysis of thetemperature-dependent magnetization has predicted a similar gap atthe same wave vector, supporting the present calculations.

MODE STRUCTURE FOR FLUID–SOLID MEDIA AS DERIVED BY LOW-FREQUENCY ASYMPTOTICS

The modes in a laterally homogeneous fluid–solid medium can be classified according to their low-frequency behaviour. For each mode, the horizontal wavenumber k(ω) will tend to a complex limit q (possibly infinite, but that appears to be exceptional) as the angular frequency ω tends to zero. The modes with vanishing wavenumber limits q can be listed explicitly, they are finite in number for each particular medium. The non-zero finite limits q appear as the zeros of certain entire analytic functions, one particular function for each fluid or solid region in the medium (and also for each Riemann sheet in the presence of homogeneous half-spaces). The resulting low-frequency mode structure can be uncovered for each fluid–solid medium by computing the wavenumber limits q as provided by the different regions. Efficient and reliable numerical techniques for this purpose are proposed for homogeneously layered media, based on compound-matrix factorization. The mode structure can be carried to higher frequencies by tracking dispersion curves. The behaviour at double roots and branch points needs special consideration. Two examples are studied in detail, one from plate acoustics and one from underwater acoustics.

An analysis of wave patterns in multiport quantum waveguide structures

Wave patterns in two- and four-port quantum waveguide structures are reported in order to analyse the operating modes of T-stub, single-branch and double-branch quantum couplers. The ballistic transport study is carried out using mode-matching techniques for solving the two-dimensional Schrödinger equation and special attention is paid to density probability and phase variations. To understand how carrier streams are driven towards the output ports, the local density of states and scattering parameters are calculated. On this basis, various geometries are considered and their operating modes including energy filtering in T-stub structures, real space transfers in a single-branch coupler and 3 dB coupling in a double branch coupler are investigated. We distinguish between operating mechanisms relying on multimode propagation and on interference processes in the monomode regime in order to investigate the origin of the directivity.

Cooperative interaction of branch signals in the actin intron of Saccharomyces cerevisiae.

In pre-mRNA splicing, specific spliceosomal components recognize key intron sequences, but the mechanisms by which splice sites are selected arenot completely understood. In the Saccharomyces cerevisiae actin intron a silent branch point-like sequence (UACUAAG) is located 7 nt upstream of the canonical sequence. Mutation of the canonicalUACUAAC sequence to UAAUAAC reduces utilization of this signal and activates the cryptic UACUAAG. Splicing-dependent beta-galactosidase assays have shown that these two splice signals cooperate to enhance splicing. Analyses of several variants of this double branch point intron demonstrate that the upstream UACUAAG sequence significantly increases usage of the UAAUAAC as a site of lariat formation. This activation is sequence-specific and unidirectional. However the ability of the UACUAAG signal to activate the downstream branch point is dependent on the presence of a short non-conserved sequence located a few nucleotides upstream of the UACUAAG. Mutation of this sequence leads to the disappearance of the cooperative interactions between the two branch signals. Our results show that this non-conserved sequence and the UACUAAG signal must both be present to achieve activation of the downstream branch point and suggest that a specific structure may be necessary to allow efficient recognition of the UAAUAAC.

Regular Comb Polystyrenes and Graft Polyisoprene/Polystyrene Copolymers with Double Branches (“Centipedes”). Quality of (1,3-Phenylene)bis(3-methyl-1-phenylpentylidene)dilithium Initiator in the Presence of Polar Additives

The synthesis of regularly spaced comb polystyrenes and graft polyisoprene/polystyrene copolymers with two branches at each junction point (centipedes) is presented. The synthetic approach involves...

Synthesis of Model Multigraft Copolymers of Butadiene with Randomly Placed Single and Double Polystyrene Branches

Model multigraft copolymers of butadiene (Bd) and styrene (St) with randomly placed trifunctional, poly(Bd-g-St), and tetrafunctional branch points, poly(Bd-g-St2), were synthesized by hydrosilylation of polybutadiene (∼92 wt % 1,4) with HSiMe2Cl and HSiMeCl2, respectively, followed by reaction of the resultant silicon−chloride groups along the backbone with polystyryllithium (PSLi). The extent of hydrosilylation was controlled by appropriate adjustment of the [silane]/[CC] ratio. Characterization carried out by size exclusion chromatography (UV and RI detector), low-angle laser light scattering, differential refractrometry, and NMR spectroscopy indicated that the synthesized branched molecules have a high degree of molecular and compositional homogeneity.