Histologic and histomorphometric analysis of bone regeneration with bovine grafting material after 24 months of healing. A case report

Anorganic bovine bone mineral matrix (ABBMM) has been reported to have osteoconductive properties and no inflammatory or adverse responses when used as grafting material in sinus augmentation procedures. However, controversy remains in regard to degradation rate of ABBMM. The aim of this study was to histologically and histomorphometrically evaluate the degradation of ABBMM in human bone samples obtained in one patient 24 months after sinus augmentation. Materials and Methods: The histologic and histomorphometric analysis was performed by means of light microscopy in three specimens harvested from the same patient, Results: After 24 months the tissue pattern appeared to be composed of residual particles, some in close contact with the newly formed bone, others separated by translucent areas and osteoid tissues. Newly-formed bone presented different levels of maturation and numerous osteocytes, with greater numbers in bone closer to the grafted particles (27.3% vs. 11.2%, p < 0.05). The histomorphometric analysis showed mean values of 40.84% newly-formed bone, 33.58% residual graft material, 23.84% marrow spaces, and 1.69% osteoid tissue, Conclusions: Even though ABBMM underwent considerable resorption, a great amount of residual grafting material was still present after two years of healing following sinus augmentation. This study confirms that the bovine grafts can be classified as long-term degradation materials

A Qualitative Approach to Transfer of Training for Managers in Leadership Development

Learning and development (L&D) professionals in a Fortune 500 company were unable to determine whether managers who completed leadership development courses were transferring what they learned to their work practices. The purpose of this qualitative single instrumental case study was to uncover the factors that accelerated or impeded the transfer of training for employees in the workplace. The conceptual framework was social cognitive learning theory with emphasis on the triadic reciprocal causation model. Guiding questions were used to explore 2 areas: (a) how managers described their preparedness to transfer the training to their jobs, and (b) how managers described their perceptions of the transfer of training from the concepts learned in class to practical job application. Data were collected through one-on-one online interviews with 12 managers who had completed a leadership development course. Data analysis included organizing the data; reading them multiple times; developing codes, categories, and themes; and interpreting the findings. Over 90% of the participants stated that they felt prepared to implement the training after the class. However, only half reported a moderate to high level of confidence incorporating the training into their work. A 3-day professional development project was designed to heighten awareness of the benefits of advancing the transference and application of training with a strong focus on driving social change in the workplace through improved interpersonal skills between managers and their direct reports

The Louisiana Calf-to-Carcass program: growth and carcass traits

Feedlot and carcass data from 1,533 weanling steers consigned to the Louisiana Calf-to-Carcass program from 1992 to 1998 were used to evaluate the influence of feeder calf grade, sire breed, and initial feedlot weight on growth and carcass traits. Each October, spring born calves were delivered to Clinton, Ruston, or Lake Charles loadout sites. Steers were identified by sire breed, tagged, weighed, assigned a feeder calf grade. Forty-six, 18, 26, and 10 percent of the steers graded large frame-thick muscle, large frame-moderate muscle, medium frame-thick muscle, and medium frame-moderate muscle, respectively. Steers were trucked to a commercial feedlot and sorted into pen lots based on predicted harvest weight and grade. Steers were harvested at approximately 1 cm fat thickness. Steers were grouped by breed of sire origin into American (Beefmaster, Braford, Brahman, Brangus, Gelbray, Red Brangus, Simbrah), English (Angus, Hereford, Red Poll), and European (Braunvieh, Charolais, Gelbvieh, Limousin, Salers, Simmental) sire breed groups. Growth and carcass traits were analyzed with a linear mixed model that included year-location as random and feeder calf grade, sire breed group, and feeder calf grade x sire breed group as fixed sources of variation. Large frame steers had .05 ± .02 kg greater feedlot average daily gain, 21 ± 4 and 10 ± 3 kg heavier harvest and hot carcass weights, 3.3 ±.8 cm2 larger ribeye areas and lower yield and quality grades than medium frame steers (P \u3c.01). Thick muscled steers were similar to moderate muscle steers for most traits. European-sired steers had larger ribeye area (P \u3c .05), larger ribeye area per 100 kg of carcass (P \u3c .05), lower yield grade (P \u3c .05), and less fat thickness (P \u3c .05) than English- and American-sired steers. English-sired steers had higher marbling score (P \u3c .05) than American- and European-sired steers. Light weight steers had lower harvest weight (P \u3c .05) and smaller ribeye area (P \u3c.05) than moderate and heavy weight steers. Generally, large frame steers and European-sired steers produced higher yielding carcasses and medium frame steers and English-sired steers produced carcasses with higher quality grade

Whistleblowing policy and corporate governance strategy

Can whistleblowing reinforce corporate governance? This will be the subject of this legal study which aims at first identifying legal instruments that exist under French law, and comparing them with those that exist abroad in order to map these mechanisms and identify the structural characteristics. Then, the vocation of whistleblowing as a lever of corporate governance will be discussed, including questioning the effectiveness of this mechanism.peer-reviewe

Evaluation of the Effects of Bioaugmentation and Biostimulation on Natural Attenuation and Biodegradation Pathways of Chlorinated Compounds in a Tidal Wetland

The usefulness of bioaugmentation and biostimulation in enhancing the natural attenuation of chlorinated compounds at a seep site at Aberdeen Proving Ground, MD was tested. The biodegradation of (1) a mixture of 1,1,2,2-tetrachloroethane, tetrachloroethene, and carbon tetrachloride, or (2) TeCA alone was compared in microcosms amended with chlorinated substrates alone, chlorinated substrates and electron donor, and chlorinated substrates, electron donor, and a TeCA-degrading enrichment culture. A third experiment evaluated the usefulness of H2 thresholds in determining the importance of co-metabolic and metabolic processes in biodegradation. TeCA biodegradation was significantly enhanced by bioaugmentation and biostimulation. However, the presence of other contaminants inhibited TeCA biodegradation, even in the presence of electron donors and the enrichment culture. H2 thresholds did not prove useful in determining the importance of metabolic and co-metabolic processes; however, evaluating each chlorinated compound individually provided insight regarding biodegradation pathways and the effects of electron donor substrates on degradation rates

Microstructural effects on the hydrogen embrittlement of high strength steels

High-strength, high-toughness steels are used in critical components of Naval aviation systems. These critical applications include landing gear components in tactical aircraft and rotary components in helicopters where large stresses must be sustained and the probability of failure due to flaws in the part are kept minimal. To prevent corrosion and wear, high strength steels are plated. When parts undergo repair/rework, the plating is stripped in an acidic bath, and the part is re-plated. During stripping and plating, as well as in-service duty, the steel is exposed to hydrogen-rich environments, which have been identified as a potential cause of premature failures in aviation system components. A high strength, precipitation hardened steel, PH 13-8Mo, one of six candidate steels, was examined in three different conditions – solution annealed (SA), H1000 (538oC aged), and H1150 (621oC aged) in order to compare the susceptibility of the different microstructures to hydrogen embrittlement and determine the stress-life curve for PH13-8 Mo in the H1000 condition. The PH 13-8Mo was selected as a result of a recent in-service failure of a reworked component.Fatigue pre-cracked compaction-tension (CT) specimen were loaded in displacement control and seated in a 10% strength hydrochloric acid bath. The load and crack mouth opening displacement (CMOD) were monitored as a function of time. From the load and CMOD versus time behavior, failure criterion were developed to determine points of crack initiation.Fractured samples were examined via scanning electron microscopy (SEM). Polished samples of the H1000, SA and H1150 condition were also analyzed by electron backscatter diffraction (EBSD). EBSD analysis showed that the packets of reverted austenite that grew in the H1150 condition material possessed an orientation that tended towards [111], which may indicate a Kurdjumov-Sachs or Nishiyama-Wasserman orientation relationship. In addition, packets of austenite within a local region also shared a common orientation with one another. An explanation for this behavior is proposed.The hydrogen embrittlement results show that the H1000 condition is highly susceptible to crack initiation over a wide range of applied stress values. A comparison of the different conditions showed that the H1150 and SA conditions possessed similar equal or better resistance to crack initiation in the hydrogen-rich environment at equivalent values of applied stress intensity (K) than the H1000 condition. Comparing equal percentages of applied (apparent) fracture toughness (KQ or KIC), only the SA condition had better resistance to initiation than the H100 condition. Resistance to crack propagation for the H1150 and SA conditions was superior to that of the H1000 condition. Finally, the threshold stress intensity, Kth, below which no cracking occurs for the H1000 condition, is on the order of 10% KIC or less, which is in good agreement with what has been established in literature.M.S., Materials Science and Engineering -- Drexel University, 201

Effects of allergen immunotherapy in the MASK-air study: a proof-of-concept analysis

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