571 research outputs found
Quantitative Assessment of the Anatomical Footprint of the C1 Pedicle Relative to the Lateral Mass: A Guide for C1 Lateral Mass Fixation
Study Design: Anatomic study. Objectives: To determine the relationship of the anatomical footprint of the C1 pedicle relative to the lateral mass (LM). Methods: Anatomic measurements were made on fresh frozen human cadaveric C1 specimens: pedicle width/height, LM width/height (minimum/maximum), LM depth, distance between LM’s medial aspect and pedicle’s medial border, distance between LM’s lateral aspect to pedicle’s lateral border, distance between pedicle’s inferior aspect and LM’s inferior border, distance between arch’s midline and pedicle’s medial border. The percentage of LM medial to the pedicle and the distance from the center of the LM to the pedicle’s medial wall were calculated. Results: A total of 42 LM were analyzed. The C1 pedicle’s lateral aspect was nearly confluent with the LM’s lateral border. Average pedicle width was 9.0 ± 1.1 mm, and average pedicle height was 5.0 ± 1.1 mm. Average LM width and depth were 17.0 ± 1.6 and 17.2 ± 1.6 mm, respectively. There was 6.9 ± 1.5 mm of bone medial to the medial C1 pedicle, which constituted 41% ± 9% of the LM’s width. The distance from C1 arch’s midline to the medial pedicle was 13.5 ± 2.0 mm. The LM’s center was 1.6 ± 1 mm lateral to the medial pedicle wall. There was on average 3.5 ± 0.6 mm of the LM inferior to the pedicle inferior border. Conclusions: The center of the lateral mass is 1.6 ± 1 mm lateral to the medial wall of the C1 pedicle and approximately 15 mm from the midline. There is 6.9 ± 1.5 mm of bone medial to the medial C1 pedicle. Thus, the medial aspect of C1 pedicle may be used as an anatomic reference for locating the center of the C1 LM for screw fixation
Nonequilibrium relaxation and scaling properties of the two-dimensional Coulomb glass in the aging regime
We employ Monte Carlo simulations to investigate the two-time density
autocorrelation function for the two-dimensional Coulomb glass. We find that
the nonequilibrium relaxation properties of this highly correlated disordered
system can be described by a full aging scaling ansatz. The scaling exponents
are non-universal, and depend on temperature and charge density.Comment: 6 pages, 3 figures included; revised version: corrected exponents,
and some additional explanations and references added; to appear in EP
Recessionary changes at work and employee well-being: the protective roles of national- and workplace institutions
The recession following the 2008 financial crisis brought major changes to employees’ experiences at work. We investigate the adverse effects of two of such changes: perceived organizational distress and job deterioration. We also examine the extent to which institutions at national level (employment protection legislation and collective bargaining coverage) and at workplace level (employment contract and union membership) may act as buffers against these effects. Using data from 21 European countries, we show that recessionary changes were associated with reduced psychological well-being and greater levels of work–nonwork interference
A Dynamic Model of Unemployment with Migration and Delayed Policy Intervention
The purpose of this paper is to build and analyse a model of unemployment, where jobs search is open to both natives and migrant workers. Markets and government intervention respond jointly to unemployment when creating new jobs. Full employment of resources is the focal point of policy action, stimulating vacancy creation. We acknowledge that policy is implemented with delays, and capture labour market outcomes by building a non-linear dynamic system. We observe jobs separation and matching, and extend our model to an open economy with migration and delayed policy intervention meant to reduce unemployment. We analyse the stability behaviour of the resulting equilibrium for our dynamic system, including models with Dirac and weak kernels. We simulate our model with alternative scenarios, where policy action towards jobs creation considers both migration and unemployment, or just unemployment
Expanding a Fixed Route Bus System with the Lower Anthracite Transit System
We worked in partnership with the Lower Anthracite Transit System (LATS) to develop a proposed bus route in the town of Sunbury, PA, expanding their system to include more of Northumberland County. This bus route is predicated upon community-based feedback through surveys, where we designed and implemented a survey analyzing general transportation desires and interest in the route. We collected 207 total responses, where community feedback in these responses informed decisions about stop locations along the route. Survey responses are hugely beneficial for LATS, allowing them to understand what aspects of their transportation services work well and what can be improved further. This can help with future cases for funding and state approvals. We also created a webpage for the organization, to increase online presence and accessibility. This included maps that we were able to develop of the existing routes that are now available through the website to view, download, and print. Altogether, our work presents a practical and efficient solution to address transportation needs within the town of Sunbury. Continued collaboration between LATS and community members, even after our work on this project is complete, is critical in finalizing a fixed-route bus service that meets the diverse needs of the populations of Mount Carmel, Shamokin, and Sunbury. By carefully considering factors such as passenger demand and route feasibility, LATS can create a system that enhances accessibility, reduces traffic congestion, and promotes sustainability
Regional population structure and young workers' wages
This paper estimates the effect that changes in the size of the youth population have on the wages of young workers. Assuming that differently aged workers are only imperfectly substitutable, economic theory predicts that individuals in larger age groups earn lower wages. We test this hypothesis for a sample of young, male, full-time employees in Western Germany during the period 1999-2010. In contrast to other studies, functional rather than administrative spatial entities are used as they provide a more accurate measure of the youth population in an actual labour market. Based on instrumental variables estimation, we show that an increase in the youth share by one percentage point is predicted to decrease a young worker's wages by 3%. Our results also suggest that a substantial part of this effect is due to members of larger age groups being more likely to be employed in lower-paying occupations
Secondary structure of rhBMP-2 in a protective biopolymeric carrier material
Efficient delivery of growth factors is one of the great challenges of tissue engineering. Polyelectrolyte multilayer films (PEM) made of biopolymers have recently emerged as an interesting carrier for delivering recombinant human bone morphogenetic protein 2 (rhBMP-2 noted here BMP-2) to cells in a matrix-bound manner. We recently showed that PEM made of poly(l-lysine) and hyaluronan (PLL/HA) can retain high and tunable quantities of BMP-2 and can deliver it to cells to induce their differentiation in osteoblasts. Here, we investigate quantitatively by Fourier transform infrared spectroscopy (FTIR) the secondary structure of BMP-2 in solution as well as trapped in a biopolymeric thin film. We reveal that the major structural elements of BMP-2 in solution are intramolecular β-sheets and unordered structures as well as α-helices. Furthermore, we studied the secondary structure of rhBMP-2 trapped in hydrated films and in dry films since drying is an important step for future applications of these bioactive films onto orthopedic biomaterials. We demonstrate that the structural elements were preserved when BMP-2 was trapped in the biopolymeric film in hydrated conditions and, to a lesser extent, in dry state. Importantly, its bioactivity was maintained after drying of the film. Our results appear highly promising for future applications of these films as coatings of biomedical materials, to deliver bioactive proteins while preserving their bioactivity upon storage in dry state.This work was supported by the French Ministry of Research through an ANR-EmergenceBIO grant (ANR-09-EBIO-012-01), by the European Commission (FP7 program) via a European Research Council starting grant (BIOMIM, GA 259370), and by GRAVIT (081012_FIBIOS). C.P. is grafetul to IUF for financial support
Heterogenität in der Konjunkturabhängigkeit von Job-zu-Job-Übergängen
Scarce empirical evidence exists for Germany regarding the cyclical aspects of worker reallocation. Furthermore, it is assumed that the cyclical influence on transition rates is the same for all demographic groups. However, one can expect that each subgroup is differentially influenced by the same cycle. Therefore, we emphasize the heterogeneity of cyclical influences for different subgroups of workers, defined by age, gender and skills, and focus on job-to-job transitions which are, in fact, found to be the largest flows in the German labor market. The findings suggest that job-to-job transitions are procyclical. The empirical framework employed here allows demographic groups to vary in their cyclical sensitivity. Female and unskilled workers experience more pronounced swings than the core group of medium-skilled, medium-aged men. By contrast, the job-to-job transition rates of high-skilled workers, old workers, as well as young workers are less influenced by cyclical behavior
Early carboniferous brachiopod faunas from the Baoshan block, west Yunnan, southwest China
38 brachiopod species in 27 genera and subgenera are described from the Yudong Formation in the Shidian-Baoshan area, west Yunnan, southwest China. New taxa include two new subgenera: Unispirifer (Septimispirifer) and Brachythyrina (Longathyrina), and seven new species: Eomarginifera yunnanensis, Marginatia cylindrica, Unispirifer (Unispirifer) xiangshanensis, Unispirifer (Septimispirifer) wafangjieensis, Brachythyrina (Brachythyrina) transversa, Brachythyrina (Longathyrina) baoshanensis, and Girtyella wafangjieensis. Based on the described material and constraints from associated coral and conodont faunas, the age of the brachiopod fauna from the Yudon Formation is considered late Tournaisian (Early Carboniferous), with a possibility extending into earlyViseacutean.<br /
Enforcement of labor regulations and job flows: evidence from Brazilian cities
The frequency of labor inspections in Brazil increased in the late 1990s. In the years that followed, between 2003 and 2007, formal employment expanded significantly in the country. This paper examines whether these city-level changes in labor inspections could be a significant factor contributing to the increase in the number of formal labor contracts at the city level. We exploit unique administrative data on formal employment on different indicators for job and worker flows—including job creation, destruction, reallocation, accessions, and separations—between 1996 and 2006, and on the intensity of labor inspections, both at the city level. The results show that increases in the enforcement of labor market regulations at the subnational level led to an increase in gross and net formal job creation rates and accession rates in a period when the Brazilian GDP and formal employment were growing and informality rates were declining. In contrast, increases in enforcement of regulations are not significantly correlated with changes in the rate of job destruction. This finding is robust to different specifications and is consistent with a model where formal jobs become more attractive to workers when enforcement of different types of labor regulations increases. JEL ClassificationJ21, J63, E24, H80, C23
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