Slender Thread Research Articles

Beyond Diagnosis: Representing the Hotline in The Slender Thread

Abstract Revisiting the little-noted 1965 film, The Slender Thread, this article argues that its representation of the suicide hotline constellates midcentury anxieties concerning psychiatric care, race, and gender. The Slender Thread provides a story of the suicide hotline at an “early crossroads” in the history of the suicide hotline as it “turned . . . toward cure and the carceral while gloving that power within the protocol of this radical care.” This is the Poitier Effect: Black fury is and must be sublated into Black care to bypass revolutionary action and insurrection.

English

Lymphatic filariasis, commonly termed as elephantiasis has been recorded since ancient Indian, Chinese, Egyptian and Persian writings.1 It is caused by a slender thread like nematode called Wuchereria bancrofti belonging to super family filaroidea.2 It exists in two morphological forms: Adult form and larvae. The adult form has a predilection for intrascrotal lymphatic vessels in hosts; thus hydrocele is one of the most common manifestations of bancroftian filariasis.3 Individuals having circulating microfilaria are outwardly healthy but have the ability to transmit infection to others through mosquito bites (Culex quinquefasciatus) 1 In developing countries like India, occurrence of genital filarial hydrocele is more common in people living in bancroftian endemic areas or in people who were previously operated for eversion of sac. We hereby report a case of hydrocele fluid with microfilaria- an incidental finding on microscopy. Wuchereria bancroti a filarial nematode inhabiting the lymphatics and transmitted through vector - culex mosquito. We hereby present a case of recurrence of genital filariasis. The patient presented with swelling of the left scrotal region with pain of dragging type. On evaluation, eosinophilia was not seen. He had a history of right hydrocele 28 years back. The aspirated hydrocele on direct microscopic examination showed presence of actively motile microfilaria which was confirmed on Giemsa staining. Recurrence is more common in bancroftian filarial endemic areas.

“But Could You Persuade Us, If We Won't Listen?”

“But Could You Persuade Us, If We Won't Listen?”

On the River Pluss: Interior of the Malay Peninsula

On the River Pluss:Interior of the Malay Peninsula X. Brau de Saint-Pol Lias Translated by Colin Dyer Editor's note: The author of this article, Marie François Xavier Joseph Jean Honoré Brau de Saint-Pol Lias (1840-1914),1 visited Sumatra and the Malay Peninsula c. 1881–81 together with J. Errington de la Croix looking for potential investing opportunities in mining or commercial agriculture. Brau d Saint-Pol Lias published several articles and books about his travels, including Perak Et Les Orangs-Sakeys: Voyage dans l'intérieur de La Presqu'ile Malaise (1883). He was active in several organizations devoted to exploration and the commercial exploitation of colonial territories, including the Société de géographie, the Société d'études colonials, and the Société de géographie commerciale. Translator's note: Unless otherwise indicated, footnotes in this translation are those of Xavier Brau de Saint-Pol Lias. Names are spelled as in the original French text. The Virgin Forest Monday 7 and Tuesday 8 February 1881 – Lying in wait for animals At first, only one elephant is on the riverbank. This is Poulo-Ganti, a small bad-tempered elephant, an old acquaintance who roars like several tigers. We refrain from mounting it with Mr Low, and the Governor settles himself on its panniers.2 And then, before we have gone ten paces, we meet the people coming to fetch us. At their head is an enormous animal, on which it seems as though the Radjah Mouda is on a second-floor balcony.3 The Governor, a very good man with the [End Page 159] Click for larger view View full resolution Perak c. 1910. Sungei Plus joins Sungei Perak north of Kuala Kangsar. Source: Map of the Malay Peninsula. London: Edward Stanford, 1910. [End Page 160] indigenous people as well as with the Europeans, strives to salute the Radjah by waving to him: 'Good day, good evening' [sic]. But the Radjah persists in not seeing the Governor, who is in front of him, and in fact well below him. He makes his elephant lie down, talking all the while to the Resident, without understanding any of the signals being made to him, and dismounts, gruffly taking his leave to hand over his animal. If one has lived outside the bounds of civilized society at any time in life, then it is not surprising to return to that again in the forest we are now penetrating.4 At first it consists of bamboo trees in large clusters, but soon it becomes a great beautiful virgin forest, like at Bédagué; because at the start of my first expedition, I had encountered nature at its most luxuriant and grandiose, it is scarcely possible to see anything more perfect. Here are giant trees that rise to prodigious heights, with a powerful thrust, and form domes of greenery impenetrable to the sun's rays. Down below are trunks with vertical compartments and jutting ridges and buttressing. Surprisingly high roots trace sinuous lines on the ground and form the veritable foundations for the construction of these colossal trees. Magnificent plants abound: the tchombang with its big red edible flower, the bretam with its immense leaves, and the great ferns. And the vines! Under the foliage they can be seen everywhere; at once graceful and terrible, these strange horizontal plants wrap themselves around others and devour them. They go upwards, downwards, they hang and they swing, passing from one tree to another, assuming diverse and bizarre shapes, flat or round, rough or smooth, green, white or dark, slender threads, wide ribbons or enormous cables. Here are soft suspensions, but elsewhere they look like the interlacing reptiles, or pythons crushing their prey. They require support from fragile shrubs but also entwine, with inextricable knots, a strong and robust hundred-year-old tree which will succumb to their grip! There are rattans, with their vast leaves slightly jagged but well armed with thorns all along the sides. These palm-vines with their long creeping stems and bristling prickles are as abundant here as on the river we have just come up. They form impenetrable, dense growths. They envelope clumps of trees...

Four new species of caddisflies (Trichoptera: Polycentropodidae, Psychomyiidae, Hydropsychidae, Odontoceridae) from Khao Nan and Tai Rom Yen National Parks, southern Thailand.

Males of four new species of caddisflies, Polyplectropus hofmaierae n. sp. (Polycentropodidae), Eoneureclipsis chinachotiae n. sp. (Psychomyiidae), Hydropsyche khaonanensis n. sp. (Hydropsychidae), and Lannapsyche tairomyenensis n. sp. (Odontoceridae) are described and illustrated. Polyplectropus hofmaierae n. sp. is distinguished from other species by the shape of the apical end of its inferior appendages and its sharp intermediate appendages. The posterior edges of their inferior appendages run slanting to the ventrodistal point and are densely covered by short and stiff bristles. Eoneureclipsis chinachotiae n. sp. is differentiated by characters of its phallus, as the first two thirds of its length are slender and slightly curved. The distal part has a dorsal hump with a very slender thread on its caudal edge and is slightly bent downward and dilated. Hydropsyche khaonanensis n. sp. can be differentiated from the other species by its phallus, in which the two apicolateral lobes in ventral view have rounded outer edges. Lannapsyche tairomyenensis n. sp. can be separated from the others by characteristics of the dorsal view of segment IX and the harpago of its inferior appendages. Segment IX is triangular with distinctly convex preanal appendages along the posterior edge of this segment, and the harpago and subapical lobes are relatively similar in shape and length.

Pearling Instabilities of a Viscoelastic Thread.

Pearling instabilities of slender viscoelastic threads have received much attention, but remain incompletely understood. We study the instabilities in polymer solutions subject to uniaxial elongational flow. Two distinctly different instabilites are observed: beads on a string and blistering. The beads-on-a-string structure arises from a capillary instability whereas the blistering instability has a different origin: it is due to a coupling between stress and polymer concentration. By varying the temperature to change the solution properties we elucidate the interplay between flow and phase separation.

Mechanism for regulation and control of emulsion droplet generation in co-flow microfluidic device via electric field

Applying the active control of electric field to the preparation of micro-droplets via the traditional microfluidic technology has attracted great attention because it can effectively improve the controllability of the preparing process. Therefore, a full understanding of mechanism for the regulation and control of microdroplets's generation by the microfluidic technology and electric field will provide interesting possibilities for the active control of producing required microdroplets in the practical applications. A transient theoretical model is developed via the coupling of phase-field method and electrostatic model to numerically investigate the generation of the single-phase droplets in a co-flow microfluidic device under the control of a uniform direct-current electric field. Via the numerical simulations based on the transient model, the control mechanisms of the electric field on dynamic behaviors of the droplets generation are revealed, and the influences of flow and electric parameters on the droplets generation characteristics are elucidated. The results indicate that the electrostatic field is able to generate an electric field force toward the inner phase fluid in the normal direction of the interface between two-phase fluids with different electric parameters. The electric field force enhances the necking and breaking of the inner fluid interface, which accelerates the droplets' generation, increases droplet deformation degree, and reduces droplet size. As the electric capillary number increases under the same hydrodynamic capillary number, the droplet formation pattern is transformed from dripping regime with only a single droplet formed per cycle to another dripping regime with one main droplet formed together with the following satellite droplets per cycle. In addition, according to the numerical results in this work, we organize a regime diagram to quantitatively represent the respective regime of these two flow patterns as a function of hydrodynamic capillary number and electric capillary number. The regime diagram indicates that with the increase in hydrodynamic capillary number and electric capillary number, the viscous drag force and electric field force are strengthened, which induces the formation of a slender liquid thread of inner fluid at the later stage of the necking process. This contributes to triggering the Rayleigh-Plateau instability on the liquid thread of inner fluid, and thus facilitating the generation of satellite droplets via the breakup of the liquid thread.

Flow Anisotropy due to Thread-Like Nanoparticle Agglomerations in Dilute Ferrofluids

Improved knowledge of the magnetic field dependent flow properties of nanoparticle-based magnetic fluids is critical to the design of biomedical applications, including drug delivery and cell sorting. To probe the rheology of ferrofluid on a sub-millimeter scale, we examine the paths of 550 μm diameter glass spheres falling due to gravity in dilute ferrofluid, imposing a uniform magnetic field at an angle with respect to the vertical. Visualization of the spheres’ trajectories is achieved using high resolution X-ray phase-contrast imaging, allowing measurement of a terminal velocity while simultaneously revealing the formation of an array of long thread-like accumulations of magnetic nanoparticles. Drag on the sphere is largest when the applied field is normal to the path of the falling sphere, and smallest when the field and trajectory are aligned. A Stokes drag-based analysis is performed to extract an empirical tensorial viscosity from the data. We propose an approximate physical model for the observed anisotropic drag, based on the resistive force theory drag acting on a fixed non-interacting array of slender threads, aligned parallel to the magnetic field.

Against Self-Reliance: The Arts of Dependence in the Early United States. William Huntting Howell. Philadelphia: University of Pennsylvania Press, 2015. Pp. 305.

<i>Against Self-Reliance: The Arts of Dependence in the Early United States</i>. William Huntting Howell. Philadelphia: University of Pennsylvania Press, 2015. Pp. 305.

Asymptotic analysis of a viscous thread extending under gravity

Despite extensive research on extensional flows, there is no complete explanation for why highly viscous fluids extending under gravity can form such persistent and stable filaments with no sign of destabilization from surface tension. We therefore investigate the motion of a slender axisymmetric viscous thread that is supported at its top by a fixed horizontal surface and extends downward under gravity. In the case in which inertia and surface tension are initially negligible, we consider the long-wavelength equations for the full initial–boundary-value problem for a thread of arbitrary initial shape. We show that, eventually, the accelerations in the thread become sufficiently large that the inertial terms become important. Thus, we keep the inertial terms and, using matched asymptotic expansions, obtain solutions for the full initial–boundary-value problem. We show that the dynamics can be divided into two generic cases that exhibit very different behaviour. In the first case, the thread develops a long thin region that joins together two fluid masses. In this case, we use order-of-magnitude estimates to show that surface-tension-driven pinching will not occur if the square root of the Reynolds number is much greater than the initial aspect ratio divided by the Bond number. In the second case, the thread becomes thin near the horizontal surface. In this case, we show that the long-wavelength equations will ultimately break down and discuss the role of inertia in determining the dynamics. The asymptotic procedures require a number of novel techniques and the resulting solutions exhibit surprisingly rich behaviour. The solution allows us to understand the mechanisms that underlie highly persistent filaments.

Effect of surfactant on the break-up of a liquid thread: Modeling, computations and experiments

The effect of insoluble surfactant on the breakup of an inviscid jet surrounded by a viscous fluid at low Reynolds number is studied both theoretically and experimentally. Equations governing the evolution of the interface and surfactant concentration are derived using long wavelength approximations. Numerical simulations of this long-wave asymptotic model show that the presence of surfactant at the interface retards the pinch-off and a slender quasi-steady thread is formed. After the formation of the thread, the diffusion of surfactant plays an important role and causes the jet to pinch. Experiments are performed and the results are presented which show that the presence of surfactant slows down the breakup of the bubble. We used high speed digital imaging to capture details of the pinching bubble in a glycerol/water mixture in the absence or presence of surfactants. Digitized video images of bubble elongation are captured sequentially in time and analyzed using image analysis software. It is found that the presence of surfactant slows down the breakup of a jet in a highly viscous exterior fluid. Experimental findings are in agreement with the theoretical and computational results.

Jeremiah’s Scribes: Creating Sermon Literature in Puritan New England. Meredith Marie Neuman. Philadelphia: University of Pennsylvania Press, 2013. Pp. vi+265.

<i>Jeremiah’s Scribes: Creating Sermon Literature in Puritan New England</i>. Meredith Marie Neuman. Philadelphia: University of Pennsylvania Press, 2013. Pp. vi+265.

Production of microbubbles from axisymmetric flow focusing in the jetting regime for moderate Reynolds numbers.

We analyze both experimentally and numerically the formation of microbubbles in the jetting regime reached when a moderately viscous liquid stream focuses a gaseous meniscus inside a converging micronozzle. If the total (stagnation) pressure of the injected gas current is fixed upstream, then there are certain conditions on which a quasisteady gas meniscus forms. The meniscus tip is sharpened by the liquid stream down to the gas molecular scale. On the other side, monodisperse collections of microbubbles can be steadily produced in the jetting regime if the feeding capillary is appropriately located inside the nozzle. In this case, the microbubble size depends on the feeding capillary position. The numerical simulations for an imposed gas flow rate show that a recirculation cell appears in the gaseous meniscus for low enough values of that parameter. The experiments allow one to conclude that the bubble pinch-off comprises two phases: (i) a stretching motion of the precursor jet where the neck radius versus the time before the pinch essentially follows a potential law, and (ii) a final stage where a very thin and slender gaseous thread forms and eventually breaks apart into a number of micron-sized bubbles. Because of the difference between the free surface and core velocities, the gaseous jet breakage differs substantially from that of liquid capillary jets and gives rise to bubbles with diameters much larger than those expected from the Rayleigh-type capillary instability. The dependency of the bubble diameter upon the flow-rate ratio agrees with the scaling law derived by A. M. Gañán-Calvo [Phys. Rev. E 69, 027301 (2004)], although a slight influence of the Reynolds number can be observed in our experiments.

Dynamics of a viscous thread on a non-planar substrate

We derive a general reduced model for the flow of a slender thread of viscous fluid on a grooved substrate. Specific choices of the substrate topography allow further analytic progress to be made, and we subsequently focus on a convection–diffusion equation governing the evolution of viscous liquid in a wedge geometry. The model equation that arises also appears in the context of foam drainage, and we take the opportunity to review and compare the results from both applications. After summarising the constant mass results, we introduce a time-dependent fluid influx at one end of the wedge. The analytical results are supported by numerical computations.

Threshold wavelength on filaments of complex fluids

The breakup into drops of complex-fluid filaments – usually jets of polymeric and surfactant solutions – plays a central role in many engineering applications ranging from crop spraying to food processing and propulsion systems. To assess the influence of interfacial perturbations in the breakup process, we followed the dynamics of the initial wavelength of surface instability on complex-fluid filaments using direct numerical simulation. We found a threshold wavelength at low Reynolds numbers corresponding to a change on the filament's configuration near breakup from large primary drops connected by slender liquid threads for wavelengths below the threshold to clearly defined satellite drops in between the primary drops for wavelengths larger than the threshold. We also found that shear-thinning effects, by reducing the viscous resistance to the Marangoni stress responsible for the formation of the satellites, cause the threshold to appear at shorter wavelengths.

Slender Threads

Interpretive dance is like marmite—you either love it or hate it. Although I am unlikely to be smearing either over my toast anytime soon, the passion and flair with which the Chickenshed theatre company presented its latest production at the Edinburgh Festival Fringe won me over to the art form, at least in part.

Research on Machining Methods of Turning Trapezoidal Thread for Slender Axle on Lathe

There were a lot of common points in turning the slender trapezoidal thread and the triangular thread on the common lathe, but there were also respective special features, because the trapezoidal thread used in machinery's transmission spot, the accuracy requirement was high, and during the machining, it was more complicated to turn the slender trapezoidal thread on the common lathe than the triangular thread. As long as control its processing rule, and adopts the correct processing method, we definitely may machine the high accuracy thread, this article elaborates ways and means of machining trapezoidal thread on slender axis, the machining of the trapezoidal thread for the slender axle can provide the experience and reference basis for such parts in the future. Introduction

Pattern formation in a thread falling onto a moving belt: An “elastic sewing machine”

We study the dynamics of instability and pattern formation in a slender elastic thread that is continuously fed onto a surface moving at constant speed V in its own plane. As V is decreased below a critical value V(c), the steady "dragged catenary" configuration of the thread becomes unstable to sinusoidal meanders and thence to a variety of more complex patterns including biperiodic meanders, figures of 8, "W," "two-by-one," and "two-by-two" patterns, and double coiling. Laboratory experiments are performed to determine the phase diagram of these patterns as a function of V, the thread feeding speed U, and the fall height H. The meandering state is quantified by measuring its amplitude and frequency as functions of V, which are consistent with a Hopf bifurcation. We formulate a numerical model for a slender elastic thread that predicts well the observed steady shapes but fails to predict the frequency of the onset of meandering, probably because of slippage of the thread relative to the belt. A comparison of our phase diagram with the analogous diagram for a thread of viscous fluid falling on a moving surface reveals many similarities, but each contains several patterns that are not found in the other.

When inordinate tissue growth is beneficial: Improving silk production by increasing silk gland size

Some 5 000 years ago, the legendary Chinese emperor Huang-Ti ordered his wife, Hsi-Ling-Shi, to find out what was damaging his mulberry trees. Hsi-Ling-Shi found white worms eating the mulberry leaves and spinning shiny cocoons. She accidentally dropped a cocoon into her tea cup and saw a delicate, slender thread unwind itself from the cocoon. The young princess had discovered silk 1, 2.

The asymptotic structure of a slender dragged viscous thread

The behaviour of a viscous thread as it falls onto a moving belt is analysed in the asymptotic limit of a slender thread. While the bending resistance of a slender thread is small, its effects are dynamically important near the contact point with the belt, where it changes the curvature and orientation of the thread. Steady flows are shown to fall into one of three distinct regimes, depending on whether the belt is moving faster than, slower than or close to the same speed as the free-fall velocity of the thread. The key dynamical balances in each regime are explained and the role of bending stresses is found to be qualitatively different. The asymptotic solutions exhibit the ‘backward-facing heel’ observed experimentally for low belt speeds, and provide the leading-order corrections to the stretching catenary in theory previously developed for high belt speeds. The asymptotic stability of the thread to the onset of meandering is also analysed. It is shown that the entire thread, rather than the bending boundary layer alone, governs the stability. A balance between the destabilising reaction forces near the belt and the restoring force of gravity on the remainder of the thread determines the onset of meandering, and an analytic estimate for the meandering frequency is thereby obtained. At leading order, neutral stability occurs with the belt moving a little more slowly than the free-fall velocity of the thread, not when the lower part of the thread begins to be under compression, but when the horizontal reaction force at the belt begins to be slightly against the direction of belt motion. The onset of meandering is the heel ‘losing its balance’.