Friction and wear behavior of glasses and ceramics

Adhesion, friction, and wear behavior of glasses and ionic solids are reviewed. These materials are shown to behave in a manner similar to other solids with respect to adhesion. Their friction characteristics are shown to be sensitive to environmental constituents and surface films. This sensitivity can be related to a reduction in adhesive bonding and the changes in surficial mechanical behavior associated with Rehbinder and Joffe effects. Both friction and wear properties of ionic crystalline solids are highly anisotropic. With metals in contact with ionic solids the fracture strength of the ionic solid and the shear strength in the metal and those properties that determine these will dictate which of the materials undergoes adhesive wear. The chemical activity of the metal plays an important role in the nature and strength of the adhesive interfacial bond that develops between the metal and a glass or ionic solid

Internalisation Theory and outward direct investment by emerging market multinationals

The rise of multinational enterprises from emerging countries (EMNEs) poses an important test for theories of the multinational enterprise such as internalisation theory. It has been contended that new phenomena need new theory. This paper proposes that internalisation theory is appropriate to analyse EMNEs. This paper examines four approaches to EMNEs—international investment strategies, domestic market imperfections, international corporate networks and domestic institutions—and three case studies—Chinese outward FDI, Indian foreign acquisitions and investment in tax havens—to show the enduring relevance and predictive power of internalisation theory. This analysis encompasses many other approaches as special cases of internalisation theory. The use of internalisation theory to analyse EMNEs is to be commended, not only because of its theoretical inclusivity, but also because it has the ability to connect and to explain seemingly desperate phenomena

Improving Care of Patients At-Risk for Osteoporosis: A Randomized Controlled Trial

BACKGROUND: Despite accurate diagnostic tests and effective therapies, the management of osteoporosis has been observed to be suboptimal in many settings. We tested the effectiveness of an intervention to improve care in patients at-risk of osteoporosis. DESIGN: Randomized controlled trial. PARTICIPANTS: Primary care physicians and their patients at-risk of osteoporosis, including women 65 years and over, men and women 45 and over with a prior fracture, and men and women 45 and over who recently used ≥90 days of oral glucocorticoids. INTERVENTION: A multifaceted program of education and reminders delivered to primary care physicians as well as mailings and automated telephone calls to patients. Outcome: Either undergoing a bone mineral density (BMD) testing or filling a prescription for a bone-active medication during the 10 months of follow-up. RESULTS: After the intervention, 144 (14%) patients in the intervention group and 97 (10%) patients in the control group received either a BMD test or filled a prescription for an osteoporosis medication. This represents a 4% absolute increase and a 45% relative increase (95% confidence interval 9–93%, p = 0.01) in osteoporosis management between the intervention and control groups. No differences between groups were observed in the incidence of fracture. CONCLUSION: An intervention targeting primary care physicians and their at-risk patients increased the frequency of BMD testing and/or filling prescriptions for osteoporosis medications. However, the absolute percentage of at-risk patients receiving osteoporosis management remained low

Evidence from GC-TRFLP that Bacterial Communities in Soil Are Lognormally Distributed

The Species Abundance Distribution (SAD) is a fundamental property of ecological communities and the form and formation of SADs have been examined for a wide range of communities including those of microorganisms. Progress in understanding microbial SADs, however, has been limited by the remarkable diversity and vast size of microbial communities. As a result, few microbial systems have been sampled with sufficient depth to generate reliable estimates of the community SAD. We have used a novel approach to characterize the SAD of bacterial communities by coupling genomic DNA fractionation with analysis of terminal restriction fragment length polymorphisms (GC-TRFLP). Examination of a soil microbial community through GC-TRFLP revealed 731 bacterial operational taxonomic units (OTUs) that followed a lognormal distribution. To recover the same 731 OTUs through analysis of DNA sequence data is estimated to require analysis of 86,264 16S rRNA sequences. The approach is examined and validated through construction and analysis of simulated microbial communities in silico. Additional simulations performed to assess the potential effects of PCR bias show that biased amplification can cause a community whose distribution follows a power-law function to appear lognormally distributed. We also show that TRFLP analysis, in contrast to GC-TRFLP, is not able to effectively distinguish between competing SAD models. Our analysis supports use of the lognormal as the null distribution for studying the SAD of bacterial communities as for plant and animal communities

Keeping the focus on children: the challenges of safeguarding children affected by domestic abuse

Safeguarding children affected by domestic abuse is a key responsibility for all professionals working with children and families, but can be difficult to achieve in practice. Despite a policy emphasis on early intervention and child-centred work, limited attention has been paid to how professionals in universal and additional support services address this important area of work. This paper reports findings from qualitative research undertaken in one local authority area in the north of England during 2011 which examines the challenges facing professionals in safeguarding children affected by domestic abuse. Six mixed professional focus groups were held, attended by a total of 23 participants. Discussion focused upon participants’ awareness of domestic abuse, how they assessed and met children and young peoples’ needs, and their views about service provision and safeguarding processes. Data were transcribed and thematic analysis undertaken. The themes presented in this paper – embodied recognition, someone else's job, service gaps, skills deficits, and focusing upon children and young people – illustrate the scope and limitations of professionals’ work with children and young people affected by domestic abuse. Areas for practice improvement are discusse

Global distribution and diversity of marine Verrucomicrobia

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in The ISME Journal 6 (2012): 1499-1505, doi:10.1038/ismej.2012.3.Verrucomicrobia is a bacterial phylum that is commonly detected in soil but little is known about the distribution and diversity of this phylum in the marine environment. To address this, we analyzed the marine microbial community composition in 506 samples from the International Census of Marine Microbes as well as eleven coastal samples taken from the California Current. These samples from both the water column and sediments covered a wide range of environmental conditions. Verrucomicrobia were present in 98% of the analyzed samples and thus appeared nearly ubiquitous in the ocean. Based on the occurrence of amplified 16S rRNA sequences, Verrucomicrobia constituted on average 2% of the water column and 1.4% of the sediment bacterial communities. The diversity of Verrucomicrobia displayed a biogeography at multiple taxonomic levels and thus, specific lineages appeared to have clear habitat preference. We found that Subdivision 1 and 4 generally dominated marine bacterial communities, whereas Subdivision 2 was confined to low salinity waters. Within the subdivisions, Verrucomicrobia community composition were significantly different in the water column compared to sediment as well as within the water column along gradients of salinity, temperature, nitrate, depth, and overall water column depth. Although we still know little about the ecophysiology of Verrucomicrobia lineages, the ubiquity of this phylum suggests that it may be important for the biogeochemical cycle of carbon in the ocean.We would like to thank the UCI Undergraduate Research Opportunity Program (S.F.), the National Science Foundation (OCE-0928544 and OCE-1046297, A.C.M.) and the Alfred P. Sloan Foundation (S.H., D.M.W., M.S.) for supporting the work

High-throughput in vivo vertebrate screening

We demonstrate a high-throughput platform for cellular-resolution in vivo chemical and genetic screens on zebrafish larvae. The system automatically loads zebrafish from reservoirs or multiwell plates, and positions and rotates them for high-speed confocal imaging and laser manipulation of both superficial and deep organs within 19 s without damage. We performed small-scale test screening of retinal axon guidance mutants and neuronal regeneration assays in combination with femtosecond laser microsurgery.National Institutes of Health (U.S.) (Director’s Innovator Award 1-DP2-OD002989–01)David & Lucile Packard Foundation (Award in Science and Engineering)Alfred P. Sloan Foundation (Award)Broad Institute of MIT and Harvard (Sparc Grant)National Science Foundation (U.S.) (Fellowship)Foxconn (Sponsorship

The impact of paratracheal lymph node metastasis in squamous cell carcinoma of the hypopharynx

The aim of this study was to analyze the prevalence and prognostic importance of paratracheal lymph nodes in squamous cell carcinoma of the hypopharynx. A retrospective review of 64 previously untreated patients with squamous cell carcinoma (SCC) of the hypopharynx that underwent surgery was performed. Ipsilateral paratracheal lymph node metastases occurred in 22% (14 out of 64) and the mean number of paratracheal lymph nodes dissected per side was 2.3 (range 1–6). Contralateral paratracheal lymph node metastases were present in 2% (1 out of 42). Sixty-seven percent with postcricoid SCC and 22% with pyriform sinus SCC developed clinical node-positive ipsilateral paratracheal lymph node metastases, whereas 11% with posterior pharyngeal wall SCC developed paratracheal metastases. There was a significant correlation between paratracheal lymph node metastasis and cervical metastasis (p = 0.005), and the primary tumor site (postcricoid, 57.1%; pyriform sinus, 20.0%; posterior pharyngeal wall, 8.3%) (p = 0.039). Patients with no evidence of paratracheal lymph node metastasis may have a survival benefit (5-year disease-specific survival rate, 60 vs. 29%). However, this result did not reach statistical significance (p = 0.071). The patients with SCC of the postcricoid and/or pyriform sinus were at risk for ipsilateral paratracheal lymph node metastasis; furthermore, patients with paratracheal node metastasis had a high frequency of cervical metastasis and a poorer prognosis. Therefore, routine ipsilateral paratracheal node dissection is recommended during the surgical treatment of patients with SCC of the postcricoid and/or pyriform sinus with clinical node metastases

The effects of walking speed on minimum toe clearance and on the temporal relationship between minimum clearance and peak swing-foot velocity in unilateral trans-tibial amputees

yesBackground: Minimum toe clearance is a critical gait event because it coincides with peak forward velocity of the swing foot, and thus, there is an increased risk of tripping and falling. Trans-tibial amputees have increased risk of tripping compared to able-bodied individuals. Assessment of toe clearance during gait is thus clinically relevant. In able-bodied gait, minimum toe clearance increases with faster walking speeds, and it is widely reported that there is synchronicity between when peak swing-foot velocity and minimum toe clearance occur. There are no such studies involving lower-limb amputees. Objectives: To determine the effects of walking speed on minimum toe clearance and on the temporal relationship between clearance and peak swing-foot velocity in unilateral trans-tibial amputees. Study design: Cross-sectional. Methods: A total of 10 trans-tibial participants walked at slow, customary and fast speeds. Minimum toe clearance and the timings of minimum toe clearance and peak swing-foot velocity were determined and compared between intact and prosthetic sides. Results: Minimum toe clearance was reduced on the prosthetic side and, unlike on the intact side, did not increase with walking speed increase. Peak swing-foot velocity consistently occurred (~0.014 s) after point of minimum toe clearance on both limbs across all walking speeds, but there was no significant difference in the toe–ground clearance between the two events. Conclusion: The absence of speed related increases in minimum toe clearance on the prosthetic side suggests that speed related modulation of toe clearance for an intact limb typically occurs at the swing-limb ankle. The temporal consistency between peak foot velocity and minimum toe clearance on each limb suggests that swing-phase inter-segmental coordination is unaffected by trans-tibial amputation. Clinical relevance The lack of increase in minimum toe clearance on the prosthetic side at higher walking speeds may potentially increase risk of tripping. Findings indicate that determining the instant of peak swing-foot velocity will also consistently identify when/where minimum toe clearance occurs