Narrow Insertion Research Articles

Higher-genus wall-crossing in Landau–Ginzburg theory

For a Fermat quasi-homogeneous polynomial, we study the associated weighted Fan–Jarvis–Ruan–Witten theory with narrow insertions. We prove a wall-crossing formula in all genera via localization on a master space, which is constructed by introducing an additional tangent vector to the moduli problem. This is a Landau–Ginzburg theory analogue of the higher-genus quasi-map wall-crossing formula proved by Ciocan-Fontanine and Kim. It generalizes the genus-0 result by Ross–Ruan and the genus-1 result by Guo–Ross.

On motion planning for narrow-clearance assemblies using virtual manikins

Digital Human Modeling (DHM) is an important tool to improve assembly ergonomics and thereby also productivity and product quality. State-of-art DHM tools can simulate challenging assembly operations by solving inverse kinematic problems so that the positions/orientations of the hands/feet of a manikin match some manually-specified targets. However, it is still difficult and time-consuming for a simulation engineer to perform an assembly with narrow insertion clearances by manually setting hand targets. We present a novel and highly automated approach that explores the 4D space (position of a fingertip plus pronation/supination of the arm) around an initial path for a sphere.

LNG-IUS 12: a 19.5 levonorgestrel-releasing intrauterine system for prevention of pregnancy for up to five years

ABSTRACTIntroduction: Globally, intrauterine devices (IUDs) are the second most commonly used form of reversible contraception because of their high efficacy, safety, convenience and cost effectiveness. The levonorgestrel releasing intrauterine system with daily average release of 20 mcg (LNG-IUS 20) is the popular choice because of its favorable bleeding patterns and many noncontraceptive benefits. A three year (LNG-IUS 8) became available three years ago. More recently, the LNG-IUS 12 was added. This new IUD shares a smaller frame, narrow inserter and lower rate of amenorrhea with the LNG-IUS 8, but it offers the five years of contraceptive protection of the LNG-IUS 20.Areas covered: This article provides information on the contraceptive efficacy, safety and tolerability of this new IUS based on approximately 60,000 cycles of use. Where available, the impacts of subject age, parity and body mass index (BMI) on study outcomes are reported.Expert opinion: This new LNG-IUS 12 with mid-dose hormone levels, smaller frame and longer effective life fills a niche that may better meet the needs of women who might appreciate the narrow insertion tube and/or the lower rates of amenorrhea. Cost will ultimately help determine success.

Anatomical Footprint of the Tibialis Anterior Tendon: Surgical Implications for Foot and Ankle Reconstructions.

This study aimed to analyze precisely the dimensions, shapes, and variations of the insertional footprints of the tibialis anterior tendon (TAT) at the medial cuneiform (MC) and first metatarsal (MT1) base. Forty-one formalin-fixed human cadaveric specimens were dissected. After preparation of the TAT footprint, standardized photographs were made and the following parameters were evaluated: the footprint length, width, area of insertion, dorsoplantar location, shape, and additional tendon slips. Twenty feet (48.8%) showed an equal insertion at the MC and MT1, another 20 feet (48.8%) had a wide insertion at the MC and a narrow insertion at the MT1, and 1 foot (2.4%) demonstrated a narrow insertion at the MC and a wide insertion at the MT1. Additional tendon slips inserting at the metatarsal shaft were found in two feet (4.8%). Regarding the dorsoplantar orientation, the footprints were located medial in 29 feet (70.7%) and medioplantar in 12 feet (29.3%). The most common shape at the MT1 base was the crescent type (75.6%) and the oval type at the MC (58.5%). The present study provided more detailed data on the dimensions and morphologic types of the tibialis anterior tendon footprint. The established anatomical data may allow for a safer surgical preparation and a more anatomical reconstruction.

Throwing-Related Injuries of the Subscapularis in Professional Baseball Players

Objectives:Injuries to the shoulder are a common cause of missed playing time in professional baseball athletes. These injuries predominately involve the supraspinatus tendon or the glenoid labrum. The purpose of this project is to describe a series of throwing-related injuries to the subscapularis muscle-tendon complex that have been previously unreported amongst baseball players. Additionally, it is the goal to describe a mechanism of injury as well as a treatment program for these athletes.Methods:A retrospective review of shoulder magnetic resonance imaging (MRI) scans of players from 1 Major League Baseball organization over the course of 5 years was performed to identify cases with findings suggestive of a subscapularis injury. The MRIs were graded and the medical records were reviewed to assess clinical findings, treatment plans, and follow-up. In the injured cohort, preinjury baseline measurements of shoulder motion including external rotation at 90° of abduction were compared to measurements from a non-injured baseball athlete cohort to evaluate whether decrease external rotation is a risk factor for this injury.Results:A total of 133 MRI scans of the shoulder were evaluated. Eleven of the 133 MRIs demonstrated signal changes suggesting subscapularis injury. Ten of these 11 patients had clinical findings supporting a diagnosis of throwing-related subscapularis strain. There were 4 grade I, 4 grade II, and 2 grade III injuries. All injuries occurred in the inferior half of the subscapularis at the myotendinous junction. Risk of subscapularis injury increased with lower levels of dominant arm external rotation (odds ratio, 0.89; 95% CI, 0.82-0.94; P < .001). A threshold of dominant arm external rotation of less than 106° demonstrated sensitivity of 0.700 (95% CI, 0.392-0.897) and specificity of 0.951 (95% CI, 0.888-0.982) for subscapularis injury. All players were treated conservatively without surgery; only 1 did not return to play. Of the remaining players, the mean number of days missed because of injury was 27 (range, 11-61 days).Conclusion:Throwing-related subscapularis injuries occur in the inferior half of the muscle at the myotendinous junction. The subscapularis muscle fibers are oriented along a fan shape because of the relatively narrow insertion on the lesser tuberosity of the proximal humerus and a broader origin on the scapula with muscle fiber alignment dependent on arm position. When the thrower's arm is at 90 degrees of abduction and external rotation, the inferior fibers of the subscapularis comes to be aligned in the transverse plane across the glenohumeral joint and are placed on greatest stretch during the late cocking and early acceleration phases of throwing. Our data suggest that there is an increased risk of these injuries with lower levels of dominant arm external rotation as this shorter arc requires greater force production by the subscapularis muscle to achieve the same peak throwing velocity.

Scattering by an array of perforated cylinders with a porous core.

In this work multiple scattering by an array of perforated cylindrical shells with a porous core has been investigated. A semi-analytical model to predict scattering from such cylindrical units is presented in the context of the multiple scattering theory (MST), and validated against laboratory experiments. The suggested semi-analytical multiple scattering model uses an impedance expression to include the perforated shell in the scattering coefficients, which is a compact way to describe a composite scatterer in MST. Calculation results of a small array are shown to be in excellent agreement with measured data. Predictions and data show that perforated cylinders with empty cavities exhibit a strong and narrow insertion loss peak at resonance, though simultaneously suffer from amplification below resonance. By adding porous material in the core of the scatterer adverse effects below the resonance peak were suppressed. In addition, it was found that the reduction peak broadens, though at a cost of a reduced peak amplitude. Finally, it has been shown that adding porous material in a perforated shell will introduce partial absorption of the incoming field, which can be optimized by adjusting the perforation ratio of the shell.

A high-power 975 nm tilted cavity laser with a 0.13 nm K−1 thermal shift of the lasing wavelength

We address design and performance issues of a 975 nm range tilted cavity laser (TCL) based on GaAs/GaAlAs waveguide and GaInAs quantum wells as an active medium. The all-epitaxial design of a TCL includes a cavity and a multilayer interference reflector (MIR). The cavity and the MIR are constructed as follows. The cavity confines one tilted optical mode, and the wavelength of this mode as a function of the tilt angle follows a first dispersion curve. The reflectivity spectrum of the MIR for tilted incidence of light has a well-pronounced stopband, and the stopband reflectivity maximum follows a second dispersion curve. The two dispersion curves intersect at one optimum tilt angle and one optimum wavelength λ0. At the wavelength λ0 the leakage loss of the optical mode through the MIR to the substrate has a minimum, which favors lasing at this optimum wavelength. The thermal shift of λ0 is governed by the shift of the intersection point. As the photon energy corresponding to the operation wavelength of the laser 975 nm is close to the resonance with the electronic energy gap in GaAs, the refractive index temperature coefficient dn/dT of GaAlAs strongly increases at the GaAs side. This gives a tool to control the thermal shift of λ0 by replacing some layers of the cavity by a superlattice containing narrow insertions of GaAs. Such a superlattice may have the same averaged refractive index at room temperature, but significantly different values of dn/dT, thus affecting the thermal shift of λ0. Within this approach broad-area (100 µm) devices have been fabricated showing a high temperature stability of the lasing wavelength (0.13 nm K−1), low threshold current density (300 A cm−2), a high power operation (>7 W in pulsed mode and >1.5 W in continuous wave mode), a high spectral stability at high output power, and a narrow vertical far-field beam divergence (FWHM ∼ 20°).

Complex genital system of a haplogyne spider (Arachnida, Araneae, Tetrablemmidae) indicates internal fertilization and full female control over transferred sperm

The female genital organs of the tetrablemmid Indicoblemma lannaianum are astonishingly complex. The copulatory orifice lies anterior to the opening of the uterus externus and leads into a narrow insertion duct that ends in a genital cavity. The genital cavity continues laterally in paired tube-like copulatory ducts, which lead into paired, large, sac-like receptacula. Each receptaculum has a sclerotized pore plate with associated gland cells. Paired small fertilization ducts originate in the receptacula and take their curved course inside the copulatory ducts. The fertilization ducts end in slit-like openings in the sclerotized posterior walls of the copulatory ducts. Huge masses of secretions forming large balls are detectable in the female receptacula. An important function of these secretory balls seems to be the encapsulation of spermatozoa in discrete packages in order to avoid the mixing of sperm from different males. In this way, sperm competition may be completely prevented or at least severely limited. Females seem to have full control over transferred sperm and be able to express preference for spermatozoa of certain males. The lumen of the sperm containing secretory balls is connected with the fertilization duct. Activated spermatozoa are only found in the uterus internus of females, which is an indication of internal fertilization. The sperm cells in the uterus internus are characterized by an extensive cytoplasm and an elongated, cone-shaped nucleus. The male genital system of I. lannaianum consists of thick testes and thin convoluted vasa deferentia that open into the wide ductus ejaculatorius. The voluminous globular palpal bulb is filled with seminal fluid consisting of a globular secretion in which only a few spermatozoa are embedded. The spermatozoa are encapsulated by a sheath produced in the genital system. The secretions in females may at least partly consist of male secretions that could be involved in the building of the secretory balls or play a role in sperm activation. The male secretions could also afford nutriments to the spermatozoa.

The medial patellofemoral ligament: a dissection study.

This study examined the anatomy including the innervation of the medial patellofemoral ligament (MPFL) and its relation to neighboring structures to help interpretation of magnetic resonance images and to improve the surgical approach to MPFL repair. The medial aspect of 39 unpreserved human knees were dissected and the MPFL and its relations to neighboring anatomical structures were measured exactly. The morphology and the attachments are described. The MPFL was present in all knees although varying in quality between individuals but not from side to side. The width of the MPFL was 1.9 cm (1.0-3.0) and length 5.3 cm (4.5-6.4). The superior edge of the MPFL medial to the vastus medialis muscle was always easily identified. Failure to identify the superior edge during MPFL surgery is therefore highly suggestive of a MPFL tear. The variation in the ratios of patella height to MPFL length and of patella width to MPFL length ratios was to high too be used to calculate the MPFL length in MPFL reconstruction surgery. The medial patellomeniscal ligament had a wide insertion at the anterior horn of the medial meniscus and a narrow insertion (0.3-0.5 cm) at the inferomedial corner of the patella in layer 3. Histological examination was made of 14 ligaments documenting the presence of free nerve endings but no mechanoreceptors.

Vascular Patterns in Stems of Araceae: Subfamilies Calloideae and Lasioideae

The stem vasculature of representative species in the four genera in the Calloideae and eight of the 17 genera in the Lasioideae was analyzed with films of series of cross sections, a technique only suitable for taxa with distinct internodes. The Calloideae are characterized by axial bundles which are more or less amphivasal and have an irregularly anastomosing vascular interconnection. The bud-trace system is short, inconspicuous, and has a narrow insertion. In the Lasioideae the climbing genera Cercestis and Rhektophyllum are most like each other but are both different from other members of the subfamily; the resemblance of Cercestis to Culcasia (Pothoideae) is recalled. Montrichardia is distinctive because of its elaborate compound-stem vascular bundles. This compound condition can be distinguished from the superficially similar arrangement found in some other taxa, e.g, Lasia, Cercestis spp, and Rhektophyllum, where there is an arrangement intermediate between simple and compound bundles. Here leaf traces and axial bundles retain their identity for some distance after association, but their vascular tissues eventually become continuous. Four distinct types of bud-trace insertion are recognized. Some comparison is possible with other subfamilies (Pothoideae, Monsteroideae) which have been examined so far in this survey.

Meckel's cartilage remnant?

AbstractCASE REPORT. A 12‐year‐old, full blood Pima Indian boy was referred to the otology clinic of the Phoenix Indian Hospital complaining of “something in my ear” found on routine physical examination. The boy had no past or present symptoms related to either ear. On physical examination the right ear was normal. The left revealed a slender, firm, skin‐covered process extending from the anterior canal wall bulge, tapering to a narrow insertion on the malleus, just inferior to the short process (Fig. 1). The tympanic membrane was otherwise normal and moved well on pneumo‐massage. Audiogram was normal (Fig. 2), as were X‐rays of the mandible and temporo‐mandibular joints. Although the boy was asymptomatic, it was felt that the chance of difficulty with accumulation of debris medial to this process was sufficient to advise surgical removal. On December 27, 1967, under general anesthesia, the attachment to the malleus was severed with a sickle knife and the anomalous process removed with a curette. It was softer in consistency than expected. Pathologic examination revealed normal cartilage (Fig. 3). Postoperative course was uneventful. The tympanic membrane was not disturbed. Hearing was unchanged.