The Impact of Returning Technical Parole Violators to Prison: A Deterrent, Null, or Criminogenic Effect

As a result of the significant U.S. prison population build-up over the past several decades, a large number of inmates are now being released from prison and returned to the community. One mechanism for facilitating this transition to the community is for inmates to be conditionally released under parole supervision. Once on parole, a parolee is subject to certain rules and conditions that, if violated, can result in a return to prison, even if not a criminal act. These types of non-criminal parole violations are typically referred to as Technical Parole Violations (TPVs). Many states return a large number of TPVs to prison each year, and TPVs contribute significantly to the prison population in many states. However, there is virtually no existing research examining what impact returning TPVs to imprisonment has on their subsequent rates of re-offending. While a large body of literature examining the overall impact of incarceration on recidivism has mostly concluded that imprisonment has a null or even slightly criminogenic effect, this overall finding is not necessarily generalizable to all sub-populations within the prison population. Strong theoretical cases can be made each way, for the impact on recidivism of incarcerating TPVs. This dissertation examines the impact on recidivism of sanctioning TPVs to imprisonment versus an alternative sanction, and also examines the dose-response impact on recidivism of varying lengths of stay in prison for a TPV, using a large sample of TPVs in one state (Pennsylvania). The bulk of the evidence supports the conclusion that recidivism rates are mostly lowered by using incarceration in response to first TPV violations. However, the evidence also suggests that the specific mechanism for lowering recidivism rates among incarcerated TPVs is largely attributable to aging and exposure time rather than to deterrence. The findings on the dose-response impact of differential lengths of stay in prison for TPVs who are sanctioned to imprisonment are more mixed. Generally the evidence suggests somewhat lowered recidivism rates attributable to longer lengths of stay in prison for a TPV violation, yet the effect sizes are generally smaller and in some cases statistically insignificant. It again appears that the particular mechanism for reduced recidivism rates associated with longer lengths of stay in prison is associated with aging and exposure time rather than with traditionally formulated deterrence mechanisms. A few contingencies of these findings are noted. First, the effect of imprisonment on recidivism among TPVs is likely highly contingent upon the swiftness, certainty, and perceived fairness of sanctioning, yet measures of these factors were not available for this study. Second, this dissertation only focuses on the first TPV violation instance after release from prison, and also is mostly limited to higher risk TPVs. Third, lower overall recidivism rates for TPVs sanctioned to imprisonment, and sanctioned for longer periods of time in prison, were influenced heavily by lower re-incarceration rates, whereas re-arrest rates did not significantly differ in any of the models. Since re-incarceration rates not only include new criminal activity but also new technical violations, it is unclear whether imprisonment for a first TPV reduces serious criminal behavior or rather mostly reduces additional technical violations and minor crimes. Future research must address these contingencies

Biomechanical and Fluoroscopic Study of a Continuously Expandable Interbody Spacer Concerning Its Role in Insertion Force and Segmental Kinematics

Study Design In vitro cadaveric study. Purpose To compare biomechanical performance, trial and implant insertion, and disc distraction during implant placement, when two interbody devices, an in situ continuously expandable spacer (CES) and a traditional static spacer (SS), were used for transforaminal lumbar interbody fusion. Overview of Literature Severe degenerative disc diseases necessitate surgical management via large spacers to increase the disc space for implants. Next-generation interbody devices that expand in situ minimize insertion forces, optimize fit between vertebral endplates, and limit nerve root retraction. However, the literature lacks characterization of insertion forces as well as details on other parameters of expandable and static spacers. Methods Ten cadaveric segments (L5–S1) were divided into two groups (n=5) and implanted with either CES or SS. Each specimen experienced unconstrained pure moment of ±6 Nm in flexion–extension, lateral bending, and axial rotation to assess the contribution of CES and SS implants in biomechanical performance. Radiographic analysis was performed during trial and implant insertion to measure distraction during spacer insertion at the posterior, central, and anterior disc regions. Pressure sensors measured the force of trial and implant insertion. Results Biomechanical analysis showed no significant differences between CES and SS in all planes of motion. A total 2.6±0.9 strikes were required for expandable spacer trials insertion and 2.6±0.5 strikes for CES insertion. A total of 8.4±3.8 strikes were required to insert SS trials and 4.2±1.6 strikes for SS insertion. The total force per surgery was 330 N for CES and 635 N for SS. Fluoroscopic analysis revealed a significant reduction in distraction during implant insertion at the posterior and anterior disc regions (CES, 0.58 and 0.14 mm; SS, 1.04 and 0.78 mm, respectively). Conclusions Results from the three study arms reveal the potential use of expandable spacers. During implant insertion, CESs provided similar stability, required less insertion force, and significantly reduced over-distraction of the annulus compared with SS

Evaluation of Two Novel Integrated Stand-Alone Spacer Designs Compared with Anterior and Anterior-Posterior Single-Level Lumbar Fusion Techniques: An Biomechanical Investigation

Study DesignIn vitro biomechanical investigation.PurposeTo compare the biomechanics of integrated three-screw and four-screw anterior interbody spacer devices and traditional techniques for treatment of degenerative disc disease.Overview of LiteratureBiomechanical literature describes investigations of operative techniques and integrated devices with four dual-stacked, diverging interbody screws; four alternating, converging screws through a polyether-ether-ketone (PEEK) spacer; and four converging screws threaded within the PEEK spacer. Conflicting reports on the stability of stand-alone devices and the influence of device design on biomechanics warrant investigation.MethodsFourteen cadaveric lumbar spines were divided randomly into two equal groups (n=7). Each spine was tested intact, after discectomy (injured), and with PEEK interbody spacer alone (S), anterior lumbar plate and spacer (AP+S), bilateral pedicle screws and spacer (BPS+S), circumferential fixation with spacer and anterior lumbar plate supplemented with BPS, and three-screw (SA3s) or four-screw (SA4s) integrated spacers. Constructs were tested in flexion-extension (FE), lateral bending (LB), and axial rotation (AR). Researchers performed one-way analysis of variance and independent t-testing (p≤0.05).ResultsInstrumented constructs showed significantly decreased motion compared with intact except the spacer-alone construct in FE and AR (p≤0.05). SA3s showed significantly decreased range of motion (ROM) compared with AP+S in LB (p≤0.05) and comparable ROM in FE and AR. The three-screw design increased stability in FE and LB with no significant differences between integrated spacers or between integrated spacers and BPS+S in all loading modes.ConclusionsIntegrated spacers provided fixation statistically equivalent to traditional techniques. Comparison of three-screw and four-screw integrated anterior lumbar interbody fusion spacers revealed no significant differences, but the longer, larger-diameter interbody spacer with three-screw design increased stabilization in FE and LB; the diverging four-screw design showed marginal improvement during AR

Assessment of Surgical Procedural Time, Pedicle Screw Accuracy, and Clinician Radiation Exposure of a Novel Robotic Navigation System Compared With Conventional Open and Percutaneous Freehand Techniques: A Cadaveric Investigation

STUDY DESIGN: Cadaveric study. OBJECTIVE: To evaluate accuracy, radiation exposure, and surgical time of a new robotic-assisted navigation (RAN) platform compared with freehand techniques in conventional open and percutaneous procedures. METHODS: Ten board-certified surgeons inserted 16 pedicle screws at T10-L5 (n = 40 per technique) in 10 human cadaveric torsos. Pedicle screws were inserted with (1) conventional MIS technique (L2-L5, patient left pedicles), (2) MIS RAN (L2-L5, patient right pedicles), (3) conventional open technique (T10-L1, patient left pedicles), and (4) open RAN (T10-L1, patient right pedicles). Output included (1) operative time, (2) number of fluoroscopic images, and (3) screw accuracy. RESULTS: In the MIS group, compared with the freehand technique, RAN allowed for use of larger screws (diameter: 6.6 ± 0.6 mm vs 6.3 ± 0.5 mm; length: 50.3 ± 4.1 mm vs 46.9 ± 3.5 mm), decreased the number of breaches \u3e2 mm (0 vs 7), fewer fluoroscopic images (0 ± 0 vs 108.3 ± 30.9), and surgical procedure time per screw (3.6 ± 0.4 minutes vs 7.6 ± 2.0 minutes) (all CONCLUSION: RAN significantly improved accuracy and decreased radiation exposure in comparison to freehand techniques in both conventional open and percutaneous surgical procedures in cadavers. RAN significantly increased setup time compared with both conventional procedures

Effects of Supplementary Cementitious Materials on Early-Age Tensile Creep and Shrinkage of Concrete

Determination of early-age tensile creep properties is critical for the performance of mass concrete structures at an early age. Due to the stress relaxation that tensile creep induces in concrete structures, accurate quantification of creep deformation is needed to determine the stress profile of the structure. Conventional methods of measuring tensile creep include the direct tension test where the concrete is subject to constant tensile stress. This method requires large quantities of concrete with embedded strain gauges which can only be used once. In this paper, the tensile creep parameters of concrete are found by using the restrained concrete ring test. The effect of Class F fly ash and ground granulated blast furnace slag on the concrete tensile creep properties was investigated. By measuring the free drying shrinkage properties of concrete using rectangular prisms, a shrinkage model was created. The main driving force behind concrete shrinkage is the loss of moisture in the ambient environment. The shrinkage model required the relative humidity inside of concrete to be known at any given time. To determine the humidity profile of concrete, experiments were conducted by inserting wireless humidity sensors inside of concrete. By using Fick’s law, a humidity model was calibrated using the experimental data. ABAQUS was used to simulate the effects of drying shrinkage and then a stress model was created. Using the modified double power law and B4 model for tensile creep of concrete, the stress relaxation parameters were varied until the modeled strains of the inner steel ring matched the experimental data. The results were compared to the creep compliance measured by dog-bone specimens subject to a constant tensile load. Results show that the modeled creep parameters obtained from the ring test match reasonably well with the creep compliance of the dog-bones. Furthermore, the modeled cracking predictions for the concrete rings match well with the experimental observations

Microstructural stability in LPE Ga{sub x}In{sub (1{minus}x)}As{sub y}Sb{sub (1{minus}y)}/GaSb heterostructures

The morphological and structural characteristics associated with the growth of lattice matched In{sub x}Ga{sub (1{minus}x)}As{sub y}Sb{sub (1{minus}y)}/GaSb (100) heterostructures is presented. The experiments focused on studying the effect of growth on vicinal surfaces tilted from the exact (100) orientation as well as variations in epilayer chemistry. It was found that variations in these process parameters had very strong effects on both the nucleation characteristics of the epilayer and the atomistic scale homogeneity of the alloy. The and variants in compositional modulation/phase separation were detected, as well as the evolution of weak (110) ordering. These results are discussed in the context of other studies on phase stability in III-V epitaxial structures, especially in terms of surface reconstruction and kinetic effects near conditions of spinodal decomposition