SMALE HORSESHOES AND CHAOS IN DISCRETIZED PERTURBED NLS SYSTEMS （Ⅰ）-POINCARE MAP

The existence of Smale horseshoes for a certain discretized perturbed nonlinear Schroedinger （NLS） equations was established by using n-dimensional versions of the Conley-Moser conditions. As a result, the discretized perturbed NLS system is shown to possess an invadant set A on which the dynamics is topologically conjugate to a shift on four symbols.

SMALE HORSESHOES AND CHAOS IN DISCRETIZED PERTURBED NLS SYSTEMS(Ⅰ)—POINCAR MAP

The existence of Smale horseshoes for a certain discretized perturbed nonlinear Schroedinger （NLS） equations was established by using n-dimensional versions of the Conley-Moser conditions. As a result, the discretized perturbed NLS system is shown to possess an invariant set A on which the dynamics is topologically conjugate to a shift on four symbols.

A study of the effect of local scour on the flow field near the spur dike

The flow field near a spur dike such as down flow and horseshoe vortex system(HVS)are susceptible to the topographic changes in the local scouring process,resulting in variation of the sediment transport with time.In this study,large eddy simulations with fixed-bed at different scouring stages were conducted to investigate the changes in flow field.The results imply that the bed deformation leads to an increase in flow rate per unit area,which represent the capability of sediment transportation by water,in the scour hole.Moreover,the intensity of turbulent kinetic energy and bimodal motion near the sand bed induced by the HVS were also varied.However,the peak moments between the two sediment transport mechanisms were different.Hence,understanding the complex feedback mechanism between topography and flow field is essential for the local scour problem.

Horseshoes for Anosov Systems on Fibers Driven by an Equicontinuous System

In this paper,we construct random horseshoes of Anosov systems driven by an equicontinuous system based on an ergodic measure with positive entropy.

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Horseshoe Kidney Congenital fusion of the lower poles of the kidneys is a relatively common (1～4/1000) congenital anomaly.CT findings of horseshoe kidney include: The isthmus extends across the aorta at the level of the inferior mesenteric artery,which prevents the normal ascent of the kidneys to the renal beds(Fig.1). The fused kidneys are low in position and malrotated with the renal pelvis directed anteriorly.Malposition commonly causes urinary stasis,stone formation, and recurrent infection.

Effects of tachyplesin on the morphology and ultrastructure of human gastric carcinoma cell line BGC-823

AIM To investigate the morphological andultrastructural changes in the human gastriccarcinoma cell line BGC-823 after being treatedwith tachyplesin.METHODS Tachyplesin was isolated from acidextracts of Chinese horseshoe crab(Tachypleustridentatus)hemocytes.BGC-823 cells and thecells treated with 2.0mg/L tachyplesin wereexamined respectively under light microscope,scanning and transmission electron microscope.RESULTS BGC-823 cells had undergone therestorational alteration in morphology andultrastructure after tachyplesin treatment.Thechanges were as follows:the shape of cells wasunanimous,the volume enlarged and cellsturned to be flat and spread,the nucleo-cytoplasmic ratio lessened and nuclear shapebecame rather regular,the number of nucleolusreduced and its volume lessened,heter-chromatin decreased while euchromatinincreased in nucleus.In the cytoplasm,mitochondria grew in number with consistentstructure relatively,Golgi complex turned to betypical and well-developed,rough endoplasmicreticulum increased and polyribosomedecreased.The microvilli at cellular surfacewere rare and the filopodia reduced whilelamellipodia increased at the cell edge.CONCLUSION Tachyplesin could alter themalignant morphological and ultrastructuralcharacteristics of human gastric carcinoma cellseffectively and have a certain inducing differen-tiation effect on human gastric carcinoma cells.

Seasonal movements of American horseshoe crabs Limulus polyphemus in the Great Bay Estuary,New Hampshire (USA)

The goal of this study was to determine the year round movement patterns of American horseshoe crabs, Limulus polyphemus, in the Great Bay Estuary, New Hampshire （USA） by using acoustic telemetry to track the movements of 37 adult Limulus, for periods ranging from 2 to 31 months. During the winter （December-March） horseshoe crabs moved very little. In the spring, when water temperatures exceeded II^C, horseshoe crabs moved at least 1 km further up into the estuary to shallower subtidal areas about a month prior to spawning. The mean distance traveled during spring migrations was 2.6 ＋ 0.5 （n=20） km up the estuary. Mating occurred in May and June and during these months animals spent most of their time in shallow subtidal areas adjacent to mating beaches. In the summer （July-Augnst）, animals moved 1.5 ± 0.5 （n=26） km down the estuary, towards the ocean, and ranged widely, using extensive portions of the estuary. In the fall （September-November） movement was more limited （0.5 ± 0.5 km; n = 24） while animals settled into wintering locations, where they remained until spring. The mean annual linear range for all animals was 4.5 ± 0.3 km （n =35） and the maximum distance traveled by an individual horseshoe crab within one year was 9.2 km. There was no evidence that any of the horseshoe crabs tracked during this study left the estuary

Seasonal movement of the American horseshoe crab Limulus polyphemus in a semi-enclosed bay on Cape Cod,Massachusetts (USA) as determined by acoustic telemetry

American horseshoe crabs Limulus polyphemus were tracked using acoustic telemetry and traditional tagging in a semi-enclosed bay on Cape Cod （Pleasant Bay）, Massachusetts, USA, to determine seasonal movement patterns. Fifty-five actively spawning females were fitted with transmitters in 2008 and 2009 and were tracked using acoustic telemetry from May 2008 through July 2010. Fil^een crabs with transmitters also had archive depth-temperature tags attached. In addition, over 2000 spawning crabs （males and females） were tagged with US Fish and Wildlife CIdSFWS） button tags over the same period. Ninety-one percent of the crabs with transmitters were detected during this study. In the spring, crabs were primarily located in the northern section of the bay near spawning beaches, whereas in the fall crabs moved towards the deeper portions of the bay, and some may have overwIntered in the bay. There was evidence that a majority （58%-71%） of the females with transmitters spawned in two sequential seasons. One archive tag was recovered resulting in a year-long continuous record of depth and tem- perature data that, when integrated with telemetry data, indicated that the crab overwintered in the bay. The live recapture rate of crabs with USFWS button tags was 11%, with all re-sighted crabs except one observed inside Pleasant Bay. Eighty-three percent of recaptures were found within 2.5kin of the tagging location, and 51% were observed at the same beach where they were tagged. This study provides further evidence that horseshoe crabs in Pleasant Bay may be philopatric to this embayment

Developmental ecology of the American horseshoe crab Limulus polyphemus

During spawning events, horseshoe crab eggs are released from the female＇s oviducts, and fertilized by one or more males. Eggs are shaped by the female into discrete clutches deposited in nests at depths of 10-20 cm on intertidal estuarine beaches. Distinguishing between fxesh eggs and the early developmental stages is obfuscated by the large amount of dense, opaque yolk. The first unambiguous confirmation of development is the formation of the rudimentary prosomatie appendages at the ＂limb bud＂ stage. Several days thereafter, the outer chorion is shed and the developing embryo expands and undergoes a series of molts within the clear inner egg membrane. The trilobite （first iustar） stage thus attained may remain within the beach sedi- ments for several more weeks, until hatching is facilitated by environmental factors such as hydration, agitation, and osmotic shock that accompany the infiltration of seawater into the nests. Trilobites exhibit endogenous eirgatidal swimming rhythms that are entrained by mechanical agitation, suggesting that peaks in larval swimming are timed to coincide with periods of high water and the inundation of the nests. Larval swimming is limited and does not appear to result in long-distance dispersal. The limited dispersal of the larvae has important implications for the population dynamics of relatively isolated populations. The rate of larval development is highly plastic and is influenced by temperature, salinity, dissolved oxygen, and the presence of pollutants. The broad environmental tolerances of horseshoe crab embryos and larvae are important in understanding their current geographic distribution and their evolutionary persistence

PERFACT procedure to treat supralevator fistula-in-ano: A novel single stage sphincter sparing procedure

AIM: To prospectively perform the PERFACT procedure in supralevator anal fistula/abscess.METHODS: Magnetic resonance imaging was done preoperatively in all the patients. Proximal cauterization around the internal opening, emptying regularly of fistula tracts and curettage of tracts(PERFACT) was done in all patients with supralevator fistula or abscess. All types of anal fistula and/or abscess with supralevator extension, whether intersphincteric or transsphincteric, were included in the study. The internal opening along with the adjacent mucosa was electrocauterized. The resulting wound was left open to heal by secondary intention so as to heal(close) the internal opening by granulation tissue. The supralevator tract/abscess was drained and thoroughly curetted. It was regularly cleaned and kept empty in the postoperative period. The primary outcome parameter was complete fistula healing. The secondary outcome parameters were return to work and change in incontinence scores(Vaizey objective scoring system) assessed preoperatively and at 3 mo after surgery.RESULTS: Seventeen patients were prospectively enrolled and followed for a median of 13 mo(range 5-21 mo). Mean age was 41.1 ± 13.4 years, M:F-15:2. Fourteen(82.4%) had a recurrent fistula, 8(47.1%) had an associated abscess, 14(82.4%) had multiple tracts and 5(29.4%) had horseshoe fistulae. Infralevator part of fistula was intersphincteric in 4 and transsphincteric in 13 patients. Two patients were excluded. Eleven out of fifteen(73.3%) were cured and 26.7%(4/15) had a recurrence. Two patients with recurrence were reoperated on with the same procedure and one was cured. Thus, the overall healing rate was 80%(12/15). All the patients could resume normal work within 48 h of surgery. There was no deterioration in incontinence scores(Vaizey objective scoring system). This is the largest series of supralevator fistula-in-ano(SLF) published to date. CONCLUSION: PERFACT procedure is an effective single step sphincter saving procedure to treat SLF with minimal risk of incontinence.

Present indications and techniques of percutaneous nephrolithotomy:What the future holds?

The purpose of the review was to present the latest updates on percutaneous nephrolithotomy(PCNL)procedure in terms of indications and evolving techniques,and to identify the advantages and disadvantages of each modality.The data for this review were collected after a thorough PubMed search in core clinical journals in English language.The key words included“PCNL”and“PNL”in combination with“indications”,“techniques”,“review”and“miniaturized PCNL”.Publications relevant to the subject were retrieved and critically reviewed.Current European and American Urology Association Nephrolithiasis Guidelines were included as well.The indications for standard PCNL have been changed through the past decade.Despite evolution of the procedure,innovations and the development of new technical approaches,the indications for miniaturized PCNL have not been standardized yet.There is a need for well-constructed randomized trials to explore the indications,complications and results for each evolving approach.A continuous reduction of tract size is not the only revolution of the last years.There is constant ongoing interest in developing new efficient miniature instruments,intracorporeal lithotripters and sophisticated tract creation methods.We can summarize that,PCNL represents a valuable well-known tool in the field of endourology.We should be open minded to future changes in surgical approaches and technological improvements.

Circadian regulation of Limulus visual functions:A role for octopamine and cAMP

The purpose of this contribution is to review our current understanding of the source and biochemistry of the circadian efferent input to the eyes of the American horseshoe crab Limuluspolyphemus and the impact of this input on the structure, physiology and biochemistry of Limulus eyes. Special emphasis is given to the role of the biogenic amine octopamine and bio- chemical cascades it activates in the eyes. In addition to reviewing published data, we present new data showing that octopamine elevates cAMP levels in Limulus lateral eyes, and we partially characterize the pharmacology of the receptors involved in this response. We also present new data showing that octopamine regulates gene expression in Limulus lateral eyes by activating a cAMP cascade

Endometriosis of the duplex appendix: A case report and review of the literature

BACKGROUND Duplication of the appendix is an infrequent congenital malformation with a complex classification.The horseshoe appendix is a subtype of the duplex appendix and is rarely reported in the literature.Endometriosis is a common gynecological disease that rarely occurs in the appendix.Moreover,horseshoe appendix combined with endometriosis has not been previously reported.CASE SUMMARY Here,we describe a 44-year-old woman who was admitted with a 1-d history of migratory lower right quadrant pain.Physical examination was consistent with the signs of acute appendicitis.The patient underwent an emergency exploratory laparotomy.The distal tip of the appendix was in contact with the cecum by another base,or“horseshoe appendix”.In addition,a small intestinal mass and an ovarian mass were identified.Subsequently,appendectomy,partial resection of the small intestine,and right oophorectomy were successively performed.The histopathology confirmed the diagnosis of acute inflammation of the duplex appendix with endometriosis,small intestine endometriosis,and ovarian endometriosis.CONCLUSION Surgeons need to be aware of the possibility of the duplex appendix when performing an appendectomy,and this study emphasizes the importance of exploring the entire abdomen.

Male horseshoe crabs Limulus polyphemus use multiple sensory cues to locate mates

The use of multisensory cues to locate mates can increase an organism＇s success by acting as a back-up plan when one system fails, by providing additional information to the receiver, and by increasing their ability to detect mates using senses that have different ranges in a variable aquatic environment. In this contribution we review the sensory cues that male horseshoe crabs Lirnulus polyphemus are known to use when locating mates and then provide new data that shed light on this subject. Dur- ing the breeding season, females migrate into shore during high tides to spawn. Males attach to females as they approach the beach or are attracted to pairs already spawning. Vision is well established as an important cue in attracting males. Although chemoreception is well known in other marine arthropods, and horseshoe crabs have the anatomy available, there are few studies on chemical cues in this species. Experiments are presented here that provide evidence for chemical cue use. We show that the attraction, and retention, of attached and satellite males to actively spawning females and mating pairs involves multimodal cues

Experimental Study on Effect of A New Vortex Control Baffler and Its Influencing Factor

The horseshoe vortex generated around the sail-body junction of submarine has an important influence on the non-uniformity of submarine wake at propeller disc. The flow characteristics in the horseshoe vortex generated area are analyzed, and a new method of vortex control baffler is presented. The influence of vortex control baffler on the flow field around submarine main body with sail is numerically simulated. The wind tunnel experiment on submarine model is carried out, and it is proved that the vortex control baffler can weaken the hoi-seshoe vortex and decrease the non-uniformity of the wake at propeller disc. It is shown from the experiment results that the effect of vortex control baffler depends on its installation position; with a proper installation position, the non-uniform coefficient of submarine wake would be declined by about 50%; the Reynolds number of submarine model has an influence on the effect of vortex control baffler too, and the higher the Reynolds number is, the better the effect of the vortex control baffler is.

Existence of horseshoe maps in voltage-mode controlled buck converters

In this paper, chaos in a voltage-mode controlled buck converter is studied. The existence of chaos is proven theoretically in this system. The proof consists of showing that the dynamics of the system is semiconjugate to that of a one-sided shift map, which implies positive entropy of the system and hence chaotic behaviour. The essential tool is the horseshoe hypotheses proposed by Kennedy and Yorke, which will be reviewed prior to the discussion of the main finding.

Experimental Study on Influences of Surface Materials on Cavitation Flow Around Hydrofoils

In order to resist on the cavitation erosion, many researchers try to change the solidity and tenacity of the coatings, but ignore the influence of surface characteristics of materials on cavitation flow and the interaction with each other. In this paper, high speed visualization system is used to observe the cavitation flow patterns in different stage. After comparing the characteristics of cavitation flow around hydrofoils made of aluminum (Foil A), stainless steel (Foil B) and the hydrofoil painted with epoxy coating (Foil C), the study shows that material has a significant effect on the cavitation flow. Firstly, when the incipient cavitation occurs, cavitation number of Foil A is highest among three hydrofoils, generating horseshoe vortex randomly. For Foil B and Foil C, it shows in the form of free bubbles. When the sheet cavitation occurs, Foil A has the highest cavitation number and shortest period, which is contrary to Foil C. And cavity consists of lots of small finger-like cavities. For Foil B and Foil C, it both constitutes with many bubbles. Compared with the high-density and small-scale cavities over surface of Foil C, the cavity of Foil B has larger scale and less density, which causes a minimal scope of influence of the re-entrant jet and strong randomness. When the cloud cavitation occurs, Foil C has the lowest cavitation number and shortest period. Secondly, compared with aluminum, both of stainless steel and epoxy coating restrains the occurrence and development of cavitation, and stainless steel and epoxy coating performs better than aluminum. For inception and sheet cavitation, stainless steel performs better than epoxy coating and aluminum. For cloud cavitation, epoxy coating performs better than stainless steel and aluminum. The objective of this paper is applied experimental method to investigate the effect of surface materials on cavitation around Clark-Y hydrofoils.

The Sediment and Hydrographic Characteristics of Three Horseshoe Crab Nursery Beaches in Hong Kong

Horseshoe crab juveniles have been recorded from sand and sandy-mud nursery beaches at Pak Nai (western New Territories), San Tau and Shui Hau (Lantau Island), Hong Kong. In order to provide a better understanding of these beaches and to identify those plausible factors which have made them preferred by spawning horseshoe crabs, environmental parameters, including temperature, salinity, pH and dissolved oxygen content of the water, and particle size distribution and organic matter content of the sediments at the three sites, were determined and compared. The hydrographic and sediment data obtained for the three study sites have revealed some common environmental features. The three nursery beaches are relatively remote, and far (in Hong Kong terms) from urbanized and densely populated areas. The beaches are generally well sheltered from strong wave action and inundated regularly by estuarine waters. Horseshoe crab adults tend to select these beaches for spawning as their protected features ensures the laid eggs are less likely to be washed out of the sand, and hatched juveniles can feed on the meiofauna and grow. Sediments of the three beaches largely comprise medium-sized sand particles and are moderately sorted, suggesting medium porosity and good water permeability. Such a sand type, with the generally high oxygen levels in incursing waters, may help create a well-oxygenated micro-environment for the normal development of horseshoe crab eggs, larvae and juveniles. Lantau Island beaches at San Tau and Shui Hau are relatively free from organic pollution, as reflected in generally high dissolved oxygen level, and low BOD 5 and ammonia nitrogen values. Pak Nai is, however, more polluted.

Horseshoe and entropy in a fractional-order unified system

This paper studies chaotic dynamics in a fractional-order unified system by means of topological horseshoe theory and numerical computation. First it finds four quadrilaterals in a carefully-chosen Poincare section, then shows that the corresponding map is semiconjugate to a shift map with four symbols. By estimating the topological entropy of the map and the original time-continuous system, it provides a computer assisted verification on existence of chaos in this system, which is much more convincible than the common method of Lyapunov exponents. This new method can potentially be used in rigorous studies of chaos in such a kind of system. This paper may be a start for proving a given fractional-order differential equation to be chaotic.

Topological horseshoe in nonlinear Bloch system

This paper demonstrates rigorous chaotic dynamics in nonlinear Bloch system by virtue of topological horseshoe and numerical method. It considers a properly chosen cross section and the corresponding Poincare map, and shows the existence of horseshoe in the Poincare map. In this way, a rigorous verification of chaos in the nonlinear Bloch system is presented.