Jones Type Research Articles

Tibial hemimelia: a surgical approach for bone reconstruction and lengthening

Tibial hemimelia is a rare condition with a reported incidence of approximately one in one million live births. Although tibial hemimeliacan vary its presentation, it often presents a shortened lower limb associated with deformities in the knee and ankle. The objective ofthis study is to present a case of tibial hemimelia and the surgical technique performed to correct the deformity and bone lengtheningusing a circular external fixator in several stages. A 15-year-old male patient was evaluated, presenting Jones type 3 tibial hemimelia(visible distal part, but no proximal) in the right lower limb associated with congenital clubfoot and ankle deformity. Studying andplanning the patient’s case was essential to classify and define the best treatment. These treatments can be flawed and often reachamputation. In the case described, several surgical approaches were performed with the objective of reconstructions and deformitycorrection, followed by limb lengthening, presenting excellent results. Level of evidence IV; Therapeutic studies; Case Report.

Revised stratigraphic sequence and type sections of the Southern Bida Basin, Nigeria

A reassessment of the stratigraphy of the Southern Bida Basin has been attempted among various disagreements. For this work, field geological mapping and stratigraphic descriptions of exposed lithologic types on outcrop sections were used. Section-by-section descriptions of important outcrops based on field observations aided in identifying lithologic units and delineating the boundaries of the sub-basin's three formations (Lokoja, Ahoko, and Agbaja). The type sections for formations in the sub-basin were not properly erected, so Jones (1958) type section has been supplemented by a more comprehensive hypostratotype, and the name Patti Formation, which is considered a misnomer in this context, has been replaced with Ahoko Formation proposed by Rahaman et al. (2019). Ahoko village is the type locality. The Agbaja Plateau, where the Agbaja Formation is best exposed, has been presented as the lectostratotype for the formation, while the revised stratigraphic succession of the Lokoja region shows the Lokoja Formation directly encompassing the Paleozoic Basement terrain, with the Maastrichtian Agbaja and Ahoko Formations (former Patti) overlying it sequentially.

Optimality of the triangular lattice for Lennard–Jones type lattice energies: a computer-assisted method

It is well-known that any Lennard–Jones type potential energy must have a periodic ground state given by a triangular lattice in dimension 2. In this paper, we describe a computer-assisted method that rigorously shows such global minimality result among 2-dimensional lattices once the exponents of the potential have been fixed. The method is applied to the widely used classical Lennard–Jones potential, which is the main result of this work. Furthermore, a new bound on the inverse density (i.e. the co-volume) for which the triangular lattice is minimal is derived, improving those found in (Bétermin and Zhang 2015 Commun. Contemp. Math. 17 1450049) and (Bétermin 2016 SIAM J. Math. Anal. 48 3236–3269). The same results are also shown to hold for other exponents as additional examples and a new conjecture implying the global optimality of a triangular lattice for any parameters is stated.

Existing fixation modalities for Jones type fifth metatarsal fracture fixation pose high rates of complications and nonunion.

Jones type fifth metatarsal fractures pose a challenge to the foot and ankle surgeon, given documented high nonunion rates as well as high complication rates including hardware prominence, nerve injury, and screw breakage for existing treatment modalities including screw and plantar plate fixation. We call for the design of innovative Jones-fracture specific implants which contour to the natural curve of the fifth metatarsal. Future research should aim to expand upon existing literature for Jones fracture fixation and evaluate efficacy of novel implants which are designed to address unacceptably high complication rates for existing treatment modalities.

Molecular kinetic modelling of nanoscale slip flow using a continuum approach

One major challenge for a continuum model to describe nanoscale confined fluid flows is the lack of a boundary condition that can capture molecular-scale slip behaviours. In this work, we propose a molecular-kinetic boundary condition to model the fluid–surface and fluid–fluid molecular interactions using the Lennard–Jones type potentials, and add a mean-field force to the momentum equation. This new boundary condition is then applied to investigate the nanoscale Couette and Poiseuille flows using the generalised hydrodynamic model developed by Guo et al. (Phys. Fluids, volume 18, issue 6, 2006a, 067107). The accuracy of our model is validated by molecular dynamics simulations and other models for a broad range of parameters including density, shear rate, wettability and channel width. Our simulation results reveal some unexpected and unintuitive slip behaviours at the nanoscale, including the epitaxial layering structure of fluids and the slip length minimum. The slip length minimum, which is analogous to the Knudsen minimum, can be explained by competing fluid–solid and fluid–fluid molecular interactions as density varies. A new scaling law is proposed for the slip length to account for not only the competing effect between the fluid–solid and fluid–fluid molecular interactions, but also many other physical mechanisms including the competition between the fluid internal potential energy and kinetic energy, and the confinement effect. While the slip length is nearly constant at the low shear rates, it increases rapidly at the high shear rates due to friction reduction. These molecular-scale slip behaviours are caused by energy corrugations at the fluid–solid interface where strong fluid–solid and fluid–fluid molecular interactions interplay.

Estimation of the error due to radial displacements in a conductivity cell (jones type)

Estimation of the error due to radial displacements in a conductivity cell (jones type)

Jones type fifth metatarsal fracture fixation in athletes: A review and current concept.

Jones type fifth metatarsal fracture is a common occurrence among athletes at all levels. These fractures may occur due to several mechanisms, but inversions and twisting injuries are considered some of the leading causes in sports. However, while Jones fracture incidences are frequent in the sporting world, there is still a lack of consensus on how such fractures should be effectively managed. There are numerous treatment options for patients with fifth metatarsal Jones fractures. The role of nonoperative treatment remains controversial, with concerns about delayed union and nonunion. Surgical stabilization of metatarsal Jones fractures is therefore often recommended for athletes, as it is often associated with a low number of complications and a higher rate of union than nonoperative management. This review will focus on literature regarding the prevalence of Jones type fifth metatarsal fracture, alongside the efficacy of both conservative and surgical treatment within this population.

Kinetic and Kinematics Parameters of Hip in Gait for a Congenital Longitudinal Tibial Deficiency with Orthoprosthesis and Transfemoral Prosthesis: A Case Study

ABSTRACT Introduction Congenital longitudinal tibial deficiency is a rare condition. It is characterized by partial or complete absence of tibia with a relatively intact fibula. Its standard treatment is surgery and employing orthoprosthesis or prosthesis. However, the effects of gaits according to the types of prosthesis is barely known. Methods Orthoprosthesis is offered to a 30-year-old man experiencing left-side congenital type 1 tibial hemimelia (classified as Jones type 1B) deficiency with thoracolumbar scoliosis and exhibiting a depressed shoulder as well as a stiff knee. He decided to have an amputation to wear a transfemoral (TF) prosthesis comprising a microprocessor-controlled knee. Results Three-dimensional gait analyses and a 6-minute walk test were performed preoperatively and postoperatively with the orthoprosthesis and TF prosthesis. Furthermore, the kinematics of hip flexion/extension and pelvic anterior/posterior tilt range of the motion degree were increased using TF prosthesis. The result of the kinetics of the hip flexion/extension moment and hip power parameters were affected using the TF prosthesis. Conclusions This case study suggests that the new prosthesis provides removable and adaptable component; further, it delivers a comfortable sitting experience because of its new socket design and knee joint flexion. Clinical Relevance Patient satisfaction is better with TF prosthesis than with orthoprosthesis. TF prosthesis is more cosmetic than orthoprosthesis, provides a symmetrical gait pattern, decreases donning and doffing durations, and there is no uncomfortable protrusion when sitting (due to amputation of the foot and leg part).

Effects of strong magnetic field on the formation of wakes in thermal QCD

We have investigated how the wakes in the induced charge density and in the potential due to the passage of highly energetic partons through a thermal QCD medium get affected by the presence of strong magnetic field [Formula: see text]. For that purpose, we wish to analyze first the dielectric responses of the medium both in presence and absence of strong magnetic field. Therefore, we have revisited the general form for the gluon self-energy tensor at finite temperature and finite magnetic field and then calculate the relevant structure functions at finite temperature and strong magnetic field limit (SMF: [Formula: see text] as well as [Formula: see text], [Formula: see text] is the electric charge (mass) of [Formula: see text]th flavor). We found that for slow moving partons, the real part of dielectric function is not affected by the magnetic field whereas for fast moving partons, for small [Formula: see text], it becomes very large and approaches towards its counterpart at [Formula: see text], for large [Formula: see text]. On the other hand the imaginary part is decreased for both slow and fast moving partons, due to the fact that the imaginary contribution due to quark loop vanishes. With these ingredients, we found that the oscillation in the (scaled) induced charge density, due to the very fast partons becomes less pronounced in the presence of strong magnetic field whereas for smaller parton velocity, no significant change is observed. For the (scaled) wake potential along the motion of fast moving partons (which is of Lennard–Jones (LJ-)type), the depth of negative minimum in the backward region gets reduced drastically, resulting in the reduction of the amplitude of oscillation. On the other hand in the forward region, it remains as the screened Coulomb one, except the screening now becomes much stronger for higher parton velocity. Similarly for the wake potential transverse to the motion of partons in both forward and backward regions, the depth of LJ potential for fast moving partons gets decreased severely, but still retains the forward–backward symm etry. However, for lower parton velocity, the magnetic field does not affect it significantly.

Treatment of tibial hemimelia jones type 4 by ankle-sparing reconstruction (from birth to skeletal maturity)

Tibial hemimelia is a relatively rare congenital preaxial longitudinal deficiency. The focus of this report is on Jones Type 4 (also called ankle diastasis). Treatment options range from amputation to tibiotalar arthrodesis with subsequent lengthening procedures. We present a case report of a patient with tibial hemimelia Jones Type 4 treated by ankle-sparing reconstruction with serial tibial- and fibular-lengthening procedures. To the best of our knowledge, this is the first report of ankle-sparing reconstruction followed until maturity.

Analysis of a Self-Consistent Description of Equilibrium Menisci and the Size Dependence of Their Formation in Slitlike Pores

The distribution of the density of the adsorbate inside the transition region of the liquid–vapor interface in a slit pore, in which the density of the substance varies both along the pore width and along the transition region between the vapor and the liquid, has been investigated. Equilibrium molecular distributions at the phase boundary are described in the framework of the discrete-continuum molecular theory in the quasi-chemical approximation, which reflects the effects of direct correlations of interacting particles. The interaction of particles is described by a pair potential of the Lennard–Jones type. The self-consistency of the description of the rough meniscus profile using kinetic (through the equality of the calculated desorption and condensation rates) and equilibrium equations has been established. The probability of the formation of a liquid phase bridge between the pore walls in slotlike porous systems is considered depending on the length of the section, the pore width and the energy of the walls.

Equation of state for dense gases from a self-consistent-field approach in the framework of kinetic theory

ABSTRACTThe departure from ideal gas behavior is described by several known equations of state (EoS), developed from a combination of theoretical considerations and experimental correlations. In this work, a different approach, in the framework of kinetic theory, is proposed: from a pairwise potential of the Lennard–Jones type, the interaction between molecules is accounted for by means of a self-consistent force field. The propagation of a perturbation wave in the dense gas or liquid of unperturbed density is described and the isothermal propagation velocity is determined. An EoS is derived and compared to the van der Waals EoS, of which it is found to reproduce the main features.

Centralization of the foot in tibial and fibular hemimelia: preliminary results

Purpose To assess the midterm results of acute centralization of the foot in cases of tibial and fibular hemimelia associated with severe foot deformity and ankle dislocation. Patients and methods We treated 11 limbs in 10 patients: eight patients with tibial hemimelia and two patients with fibular hemimelia. All cases were associated with severe foot deformity (equinovarus in tibial hemimelia and equinovalgus in fibular hemimelia), dislocated ankle, and tight tendoachilis. There were seven boys and three girls, with a mean age of 2.35 years. In tibial hemimelia, two limbs were type Ia, four limbs were type II, and three limbs were type IV according to Jones classification. In fibular hemimelia, all cases were type II according to Achterman and Kalamachi classification. The mean preoperative limb-length discrepancy was 5.4 cm (range, 4.5–7 cm). We had acute centralization of the foot by means of calcaneofibular or tibiocalcaneal arthrodesis in cases of tibial or fibular hemimelia, respectively, and talectomy, fibular shortening, and tibiofibular synostosis were done. Transcalcaneal fibular Kirschner wire was inserted to maintain the foot position. First-stage lengthening by Ilizarov fixator was done, with 5-cm gain of length in seven cases, and second-stage lengthening was done in two cases. Results The mean follow-up period was 50 months. We achieved foot correction and centralization of the foot, which was stable in all cases, except one with failed tibiofibular synostosis in Jones type IV. No neurovascular complications occurred. Wound dehiscence occurred in five limbs, unstable knee was seen in two cases, recurrent equinus of more than 20° was seen in three cases, and two cases had poor regenerate potential. All patients and families were satisfied with the foot procedure and were not satisfied with knee centralization procedure owing to knee instability. Conclusion Acute centralization of the severely deformed foot in cases of tibial and fibular hemimelia by calcaneofibular or tibiocalcaneal arthrodesis, respectively, can correct severe foot deformity, achieve plantigrade foot, and preserve the patient but was associated with many secondary procedures. Level of evidence Level IV.

Limb reconstruction for tibial hemimelia

Background Tibial hemimelia is a rare congenital anomaly and is usually accompanied by congenital abnormalities in other parts in the body. The treatment is always difficult and challenging. Amputation was the preferred treatment option; however, a reconstructive surgery is sometimes used in the cases of amputation refusal. Aim The purpose of this study was to determine the results of limb reconstruction in eight children with Jones type II tibial hemimelia by fibular tibialization, ankle fusion, and lower limb lengthening using Ilizarov external fixator. Patients and methods A retrospective study was conducted on eight children presented with Jones type II tibial hemimelia, who were treated by fibular tibialization, ankle fusion, and lower limb lengthening using Ilizarov external fixator. The study had been done at Zagazig University hospitals between March 2007 and October 2014. The mean age of the patients was 3 years (range, 2–5 years). There were five girls and three boys. All had unilateral affection; right side was affected in five children and left in three. All cases had leg-length discrepancy that ranged from 5 to 7 cm, and all feet had equinovarus deformity. Results The mean follow-up period was 3 years (range, 2–5 years). In all the cases, the transferred fibular shaft to the distal end of the tibial remnant was united within 2–3 months. Consolidation of the bone at the distraction site was obtained with a gained length of 5–6.5 cm in all patients. The external fixator was applied for an average time of 150 days, and the healing index was 29 days/cm. The mean maximum knee flexion was 100° (range 90°–110°], and instability of less than 5° in varus valgus plane was seen in two cases. The ankle and foot deformity improved by foot repositioning and arthrodesis, achieving a plantigrade foot. The mean calcaneofibular angle was 100° (range, 90°–110°). The parents of all the patients showed full satisfaction at the latest follow-up. Conclusion The results of limb reconstruction of the Jones type II tibial hemimelia by fibular tibialization, ankle fusion, and lower limb lengthening using Ilizarov external fixator were acceptable. The limb was saved and reconstructed.

Discrete Particle Methods for Simulating Quasi-Static Load and Hypervelocity Impact Phenomena

In this paper, we introduce a mesh-free computational model for the simulation of high-speed impact phenomena. Within the framework of particle dynamics simulations we model a macroscopic solid ceramic tile as a network of overlapping discrete particles of microscopic size. Using potentials of the Lennard–Jones type, we integrate the classical Newtonian equations of motion and perform uni-axial, quasi-static load simulations to customize our three model parameters to the typical tensile strength, Young’s modulus and the compressive strength of a ceramic. Subsequently we perform shock load simulations in a standard experimental setup, the edge-on impact (EOI) configuration. Our obtained results concerning crack initiation and propagation through the material agree well with corresponding high-speed EOI experiments with Aluminum Oxinitride (AlON), Aluminum Oxide [Formula: see text] and Silicon Carbide (SiC), performed at the Fraunhofer Ernst-Mach-Institute (EMI). Additionally, we present initial simulation results where we use our particle–based model to simulate a second type of high-speed impact experiments where an accelerated sphere strikes a thin aluminum plate. Such experiments are done at our institute to investigate the debris clouds arising from such impacts, which constitute a miniature model version of a generic satellite structure that is hit by debris in the earth’s orbit. Our findings are that a discrete particle based method leads to very stable, energy-conserving simulations of high–speed impact scenarios. Our chosen interaction model works particularly well in the velocity range where the local stresses caused by impact shock waves markedly exceed the ultimate material strength.

Posterior tibial slope angle is associated with flexion-type Salter-Harris II and Watson-Jones type IV fractures of the proximal tibia.

Flexion-type Salter-Harris (SH) II fractures of the proximal tibia, also described as Watson-Jones (WJ) IV fractures, are rare injuries reported among adolescent athletes who are close to skeletal maturity and remain elusive. Due to this classification disagreement, the various treatments range from nonoperative to operative types, and no previous studies have explained the mechanisms of injury or the source of the fracture forces. This retrospective matched case-control study aimed to identify radiological factors that are associated with the fracture forces and to elucidate the mechanisms of these injuries. Sixteen flexion-type SH II/WJ IV fractures of the proximal tibia in 12 adolescents (12 males, mean age of 14.6years) were retrospectively reviewed, and knee alignment on plain radiographs was assessed to compare the radiological outcomes of the operated knees (n = 7), nonoperated knees (n = 9), and uninjured contralateral knees (n = 8). The results were compared to healthy age- and sex-matched control subjects (n = 24 knees). With regard to the radiological outcomes, the posterior tibial slope angle (PTSA) was significantly greater in the nonoperated knees (19.0° ± 1.6°), operated knees (16.8° ± 1.3°), and uninjured knees (13.6° ± 1.3°) than in the healthy knees of the matched control subjects (9.6° ± 0.4°). The anatomical tibiofemoral angle was significantly less in the nonoperated knees (0.7° ± 0.6°) than in the healthy knees of the matched control subjects (3.7° ± 0.4°). These findings suggest a relationship between an increased PTSA and flexion-type SH II/WJ IV fractures of the proximal tibia, considering the deteriorating effects of an increased PTSA on knee kinematics. Adolescent active athletes with an increased PTSA and partially closed epiphysis of the proximal tibia are at risk for suffering from flexion-type SH II/WJ IV fractures of the proximal tibia until the closure of the proximal tibial epiphysis. Case-control study, Level III.

Local variational study of 2d lattice energies and application to Lennard–Jones type interactions

In this paper, we focus on finite Bravais lattice energies per point in two dimensions. We compute the first and second derivatives of these energies. We prove that the Hessian at the square and the triangular lattice are diagonal and we give simple sufficient conditions for the local minimality of these lattices. Furthermore, we apply our result to Lennard–Jones type interacting potentials that appear to be accurate in many physical and biological models. The goal of this investigation is to understand how the minimum of the Lennard–Jones lattice energy varies with respect to the density of the points. Considering the lattices of fixed area A, we find the maximal open set to which A must belong so that the triangular lattice is a minimizer (resp. a maximizer) among lattices of area A. Similarly, we find the maximal open set to which A must belong so that the square lattice is a minimizer (resp. a saddle point). Finally, we present a complete conjecture, based on numerical investigations and rigorous results among rhombic and rectangular lattices, for the minimality of the classical Lennard–Jones energy per point with respect to its area. In particular, we prove that the minimizer is a rectangular lattice if the area is sufficiently large.

Recovery of iron particles from waste water treatment plant of an iron and steel factory

Waste mud from the waste water treatment plant of an iron and steel factory has been investigated due to the recovery possibility of the magnetic materials. Mud samples was firstly expired due to the its chemical content with an XRF spectrometric method. Due to the XRF spectrometric analyses the mud sample had 30.72% magnetic content. This result motivated the experimental study. Dried mud sample grinded and sieved to define the particulate size and it is determined that about 66.67% of has the grain size lower than 50 µm. To gain the magnetic content efficiently, Jones type magnetic separation has been done under 17,000 Gauss on four different mud samples. It is determined that 69.59% of the mud sample compost of magnetic materials and 51.83% of this rate is simply iron base due to the XRF spectrometric analyses. As a result, 36.06% of the mud is the iron, 33.53% magnetic content out of iron and 30.41% is nonmagnetic composition. Economic value of the wasted potential is about 969,292.8 $ annually. The payback period estimated approximately about 10 months, by the investment of a separation units these are costs about 750,000 $ and annual electricity consumption is 64,751.8 $.

EVALUASI PROGRAM INVESTASI PENGELOLAAN SUMBER DAYA AIR TERPADU CITARUM

Berbagai kebijakan dan program telah dilaksanakan untuk memperbaiki sungai Citarum, salah satunya Program Investasi Pengelolaan Sumber Daya Air Terpadu citarum atau Integrated Citarum Water Resources Management Investment Program ( ICWRMIP) tetapi kenyataannya tiap tahun kondisinya makin kritis. Penelitian ini bertujuan untuk melakukan evaluasi sebagai penilaian pencapaian kinerja dari implementasi Program Investasi Pengelolaan Sumber Daya Air Terpadu citarum atau Integrated Citarum Water Resources Management Investment Program (ICWRMIP) berdasarkan konsep Jones (1991: 359) tipe evaluasi kebijakan yaitu: 1. Political Evaluation;
 2.Organizational evaluation; 3. Substantive evaluation dan konsep Riant Nuguroho (2011 : 665) bahwa pengendalian kebijakan terdiri dari: 1. Monitoring kebijakan atau pengawasan kebijakan; 2. Evaluasi kebijakan;
 3.Pengganjaran. Metode penelitian yang digunakan dalam penelitian ini yaitu metode deskripitif kualitatif.Teknik penentuan informan yang digunakan dengan teknik purposive sampling. Teknik pengumpulan data dengan melakukan wawancara mendalam, observasi, studi pustaka dan dokumentasi. Hasil penelitian diketahui bahwa belum dilakukan pengendalian, masih dalam menginventarisir permasalahan untuk menyamakan database permasalahan yang ada. umpan balik masih berupa solusi yang coba ditawarkan oleh pihak - pihak pelaksana yang merupakan organisasi-organisasi pemerintah/instansi pemerintah. Hal ini juga dimungkinkan karena tidak ada pengganjaran baik reward dan punishment terhadap sumber daya manusia yang ikut terlibat dalam pengelolaan Sumber Daya Air Citarum.

Kauffman–Jones polynomial of a curve on a surface

We introduce a Kauffman–Jones type polynomial [Formula: see text] for a curve [Formula: see text] on an oriented surface, whose endpoints are on the boundary of the surface. The polynomial [Formula: see text] is a Laurent polynomial in one variable [Formula: see text] and is an invariant of the homotopy class of [Formula: see text]. As an application, we obtain an estimate in terms of the span of [Formula: see text] for the minimum self-intersection number of a curve within its homotopy class. We then give a chord diagrammatic description of [Formula: see text] and show some computational results on the span of [Formula: see text].