Medial Patellofemoral Ligament Repair With Suture Tape Augmentation

The medial patellofemoral ligament (MPFL) is the main restraining force in the first 20° of flexion against lateral patellar displacement and is disrupted after patellar subluxation or dislocation. MPFL reconstruction is frequently performed when conservative management fails and the patient has recurrent patellar dislocations. However, a variety of complications have been reported in the literature with this procedure. Internal bracing with suture tape augmentation encourages healing and allows early mobilization. This article describes, with video illustration, MPFL repair with suture tape augmentation

Anterolateral Ligament Repair With Suture Tape Augmentation

Recent insights into the structure and function of the anterolateral ligament (ALL) of the knee has resulted in a recognition of its contribution in rotational control of the knee. Several ALL reconstruction techniques have been described in the literature. This article describes, with video illustration, a percutaneous repair technique using suture tape augmentation. A tendon graft is not needed. This technique allows early mobilization and encourages natural healing of the ligament by protecting the ligament during the healing phase as a secondary stabilizer

Posterolateral Corner Repair With Suture Tape Augmentation

The posterolateral corner (PLC) of the knee is the main restraint to varus forces of the knee as well as posterolateral rotation of the tibia relative to the femur. Primary PLC repairs have been associated with a high failure rate in past literature. However, with modern improved arthroscopic instrumentation and devices, there has been a renewed interest in repair of the ligaments around the knee. Internal bracing with suture tape augmentation encourages healing and allows early mobilization. This article describes, with video illustration, PLC repair with suture tape augmentation

Anterior Cruciate Ligament Repair Using Independent Suture Tape Reinforcement

Recently there has been renewed interest in primary repair of the anterior cruciate ligament (ACL). Repair of the acute proximal ruptured ACL can be achieved with the independent suture tape reinforcement ACL repair technique. The independent suture tape reinforcement technique reinforces the ligament as a secondary stabilizer, encouraging natural healing of the ligament by protecting it during the healing phase and supporting early mobilization. The purpose of this article is to describe, with video illustration, this ACL repair technique

General Relativity in Electrical Engineering

In electrical engineering metamaterials have been developed that offer unprecedented control over electromagnetic fields. Here we show that general relativity lends the theoretical tools for designing devices made of such versatile materials. Given a desired device function, the theory describes the electromagnetic properties that turn this function into fact. We consider media that facilitate space-time transformations and include negative refraction. Our theory unifies the concepts operating behind the scenes of perfect invisibility devices, perfect lenses, the optical Aharonov-Bohm effect and electromagnetic analogs of the event horizon, and may lead to further applications

Hidden Hunger: Solutions for America’s Aging Populations

The global population, including the United States, is experiencing a demographic shift with the proportion of older adults (aged ≥ 65 years) growing faster than any other age group. This demographic group is at higher risk for developing nutrition-related chronic conditions such as heart disease and diabetes as well as infections such as influenza and pneumonia. As a result, an emphasis on nutrition is instrumental for disease risk reduction. Unfortunately, inadequate nutrient status or deficiency, often termed hidden hunger, disproportionately affects older adults because of systematic healthcare, environmental, and biological challenges. This report summarizes the unique nutrition challenges facing the aging population and identifies strategies, interventions, and policies to address hidden hunger among the older adults, discussed at the scientific symposium “Hidden Hunger: Solutions for America’s Aging Population”, on March 23, 2018

Visualizing the Interface of Biotin and Fatty Acid Biosynthesis through SuFEx Probes

Site-specific covalent conjugation offers a powerful tool to identify and understand protein-protein interactions. In this study, we discover that sulfur fluoride exchange (SuFEx) warheads effectively crosslink the Escherichia coli acyl carrier protein (AcpP) with its partner BioF, a key pyridoxal 5′-phosphate (PLP)-dependent enzyme in the early steps of biotin biosynthesis by targeting a tyrosine residue proximal to the active site. We identify the site of crosslink by MS/MS analysis of the peptide originating from both partners. We further evaluate the BioF-AcpP interface through protein crystallography and mutational studies. Among the AcpP-interacting BioF surface residues, three critical arginine residues appear to be involved in AcpP recognition so that pimeloyl-AcpP can serve as the acyl donor for PLP-mediated catalysis. These findings validate an evolutionary gain-of-function for BioF, allowing the organism to build biotin directly from fatty acid biosynthesis through surface modifications selective for salt bridge formation with acidic AcpP residues.</p

Crises and collective socio-economic phenomena: simple models and challenges

Financial and economic history is strewn with bubbles and crashes, booms and busts, crises and upheavals of all sorts. Understanding the origin of these events is arguably one of the most important problems in economic theory. In this paper, we review recent efforts to include heterogeneities and interactions in models of decision. We argue that the Random Field Ising model (RFIM) indeed provides a unifying framework to account for many collective socio-economic phenomena that lead to sudden ruptures and crises. We discuss different models that can capture potentially destabilising self-referential feedback loops, induced either by herding, i.e. reference to peers, or trending, i.e. reference to the past, and account for some of the phenomenology missing in the standard models. We discuss some empirically testable predictions of these models, for example robust signatures of RFIM-like herding effects, or the logarithmic decay of spatial correlations of voting patterns. One of the most striking result, inspired by statistical physics methods, is that Adam Smith's invisible hand can badly fail at solving simple coordination problems. We also insist on the issue of time-scales, that can be extremely long in some cases, and prevent socially optimal equilibria to be reached. As a theoretical challenge, the study of so-called "detailed-balance" violating decision rules is needed to decide whether conclusions based on current models (that all assume detailed-balance) are indeed robust and generic.Comment: Review paper accepted for a special issue of J Stat Phys; several minor improvements along reviewers' comment