The chronology of Gezer from the end of the late bronze age to iron age II: A meeting point for radiocarbon, archaeology egyptology and the Bible.

The ancient southern Levantine city of Gezer is well-known from Egyptian, Biblical and Assyrian sources, associated with power struggles, conquests, and intriguing tales involving figures such as Milkilu and Amenhotep III, Merneptah, the Philistines, Solomon and his unidentified pharaonic father-in-law, and Shishak / Sheshonq I. Since the identity of Gezer with "Tell Jezer" is quite literally 'set in stone' by some dozen boundary inscriptions, along with impressive Bronze and Iron Age remains, research at this site provides a unique opportunity to compare text and archaeology, as well as bring to light the undocumented everyday lives of the city's inhabitants. In this endeavour, independent scientific dating is crucial for anchoring the remains chronologically. This paper presents the first substantial radiocarbon dataset and Bayesian chronological analysis for Gezer spanning the last part of the Late Bronze Age (LBA; LB IIB) through Iron Age II. The dataset derives from an essentially continuous stratigraphic sequence exposed in recent years by the Tandy expedition along the central-southern edge of the site. The results allow us for the first time to independently determine the site chronology, test the viability (from a chronological perspective) of proposed historical correlations, and contribute to debates on Philistine and Iron Age chronology.

Coupled Turbidity and Spectroscopy Problems: A Simple Algorithm for Volumetric Analysis of Optically Thin or Dilute, In Vitro Bacterial Cultures in Various Media.

An approach binary spectronephelometry (BSN) to perform real-time simultaneous noninvasive in situ physical and chemical analysis of bacterial cultures in fluid media is described. We choose to characterize cultures of Escherichia coli (NC), Pseudomonas aeruginosa (PA), and Shewanella oneidensis (SO) in the specific case of complex media whose Raman spectrum cannot be unambiguously assigned. Nevertheless, organism number density and a measure of the chemical makeup of the fluid medium can be monitored noninvasively, simultaneously, and continuously, despite changing turbidity and medium chemistry. The method involves irradiating a culture in fluid medium in an appropriate vessel (in this case a standard 1 cm cuvette) using a near infrared laser and collecting all the backscattered light from the cuvette, i.e., the Rayleigh-Mie line and the inelastically emitted light which includes unresolved Raman scattered light and fluorescence. Complex "legacy" media contain materials of biological origin whose chemical composition cannot be fully delineated. We independently calibrate this approach to a commonly used reference, optical density at 600 nm (OD600) for characterizing the number density of organisms. We suggest that the total inelastically emitted light could be a measure of the chemical state of a biologically based medium, e.g., lysogeny broth (LB). This approach may be useful in a broad range of basic and applied studies and enterprises that utilize bacterial cultures in any medium or container that permits optical probing in the single scattering limit.

Novel Spiked-Washer Repair Is Biomechanically Superior to Suture and Bone Tunnels for Arcuate Fracture Repair.

OBJECTIVES: Injuries to the posterolateral corner of the knee can lead to chronic degenerative changes, external rotation instability, and varus instability if not repaired adequately. A proximal fibula avulsion fracture, referred to as an arcuate fracture, has been described in the literature, but a definitive repair technique has yet to be described. The objective of this study was to present a novel arcuate fracture repair technique, using a spiked-washer with an intramedullary screw, and to compare its biomechanical integrity to a previously described suture and bone tunnel method. METHODS: Ten fresh-frozen cadaveric knees underwent a proximal fibula osteotomy to simulate a proximal fibula avulsion fracture. The lateral knee capsule and posterior cruciate ligament were also sectioned to create maximal varus instability. Five fibulas were repaired using a novel spiked-washer technique and the other 5 were repaired using the suture and bone tunnel method. The repaired knees were subjected to a monotonic varus load using a mechanical testing system instrument until failure of the repair or associated posterolateral corner structures. RESULTS: Compared with the suture repair group, the spiked-washer repair group demonstrated a 100% increase in stiffness, 100% increase in yield, 110% increase in failure force, and 108% increase in energy to failure. CONCLUSIONS: The spiked-washer technique offers superior quasi-static biomechanical performance compared with suture repair with bone tunnels for arcuate fractures of the proximal fibula. Further clinical investigation of this technique is warranted and the results of this testing may lead to improved outcomes and patient satisfaction for proximal fibula avulsion fractures.

In vivo murine model of continuous intramedullary infusion of particles--a preliminary study.

Continued production of wear debris affects both initial osseointegration and subsequent bone remodeling of total joint replacements (TJRs). However, continuous delivery of clinically relevant particles using a viable, cost effective, quantitative animal model to simulate the scenario in humans has been a challenge for orthopedic researchers. In this study, we successfully infused blue-dyed polystyrene particles, similar in size to wear debris in humans, to the intramedullary space of the mouse femur for 4 weeks using an osmotic pump. Approximately 40% of the original particle load (85 microL) was delivered into the intramedullary space, an estimate of 3 x 10(9) particles. The visible blue dye carried by the particles confirmed the delivery. This model demonstrated that continuous infusion of particles to the murine bone-implant interface is possible. In vivo biological processes associated using wear debris particles can be studied using this new animal model.

Continuous intramedullary polymer particle infusion using a murine femoral explant model.

In vitro models are important investigative tools in understanding the biological processes involved in wear-particle-induced chronic inflammation and periprosthetic osteolysis. In the clinical scenario, particles are produced and delivered continuously over extended periods of time. Previously, we quantified the delivery of both polystyrene and polyethylene particles over 2- and 4-week time periods using osmotic pumps and collection tubes. In the present study, we used explanted mice femora in organ culture and showed that continuous intramedullary delivery of submicron-sized polymer particles using osmotic pumps is feasible. Furthermore, infusion of 2.60 x 10(11) particles per mL (intermediate concentration) of ultrahigh molecular weight polyethylene (UHMWPE) for 2 weeks and 8.06 x 10(11) particles per mL (high concentration) UHMWPE for 4 weeks both yielded significantly higher scores for bone loss when compared with controls in which only mouse serum was infused.

Validation and quantification of an in vitro model of continuous infusion of submicron-sized particles.

Wear particles produced from total joint replacements have been shown to stimulate a foreign body and chronic inflammatory reaction that results in periprosthetic osteolysis. Most animal models that simulate these events have used a single injection of particles, which is not representative of the clinical scenario, in which particles are continuously generated. The goal of this study was to evaluate the feasibility of an osmotic pump for the continuous delivery of clinically relevant submicron-sized particles over an extended period of time. Blue-dyed polystyrene particles and retrieved ultra-high molecular weight polyethylene (UHMWPE) particles, both suspended in mouse serum, were loaded into an Alzet mini-osmotic pump. Pumps were attached to vinyl tubing that ended with hollow titanium rods, simulating a metal implant, which was suspended in a collection vessel. The number of particles collected was evaluated over 2- and 4-week time periods. Delivery of both the polystyrene and UHMWPE particles was feasible over pump concentrations of 10(9) to 10(11) particles per pump. Furthermore, delivery efficiency of polystyrene particles decreased with increasing initial particle concentration, whereas delivery efficiency of UHMWPE particles increased slightly with increasing initial particle concentration. For UHMWPE, approximately one-third of the particles in the pump were collected at 4 weeks. This in vitro study has quantified the efficiency of a unique particle pumping system that may be used in future in vivo investigations to develop a murine model of continuous particle infusion.

Subretinal suture misdirection during 360 degrees suture trabeculotomy.

PURPOSE: To report a new complication of 360 degrees suture trabeculotomy attributable to subretinal suture misdirection. DESIGN: Observational case report. METHODS: Retrospective chart review. RESULTS: A 5-month-old female with bilateral congenital glaucoma underwent uncomplicated 360 degrees suture trabeculotomy in the right eye. In the left eye, a scleral flap was created and dissection to Schlemm's canal was achieved. A 6-0 Prolene suture was passed into Schlemm's canal long enough for 360 degrees of treatment, did not come out the opening, and was retracted. The procedure was completed with a trabeculotome. One month later, an unusual white tract was noted subretinally in the left eye. There was no overlying retinal break or detachment. The tract presumably was caused by the misdirected Prolene suture exiting Schlemm's canal prematurely and being directed posteriorly. CONCLUSIONS: Suture misdirection subretinally during cannulation of Schlemm's canal should be considered a possible complication of 360 degrees suture trabeculotomy.