Optimal management of posterior cruciate ligament injuries: current perspectives

Background: The optimal management of posterior cruciate ligament (PCL) injuries is debated by orthopedic surgeons. A natural history study (NHS) of acute, isolated PCL tears in patients with a mean follow-up of 14.3 years was previously published. The purpose of this study was to compare and contrast the results of the NHS study with those of other studies with similar follow-up time after operative and nonoperative management of isolated PCL tears. Material and methods: With reviewing the literature, six operative management and six nonoperative management studies were found for treating isolated PCL injuries. We analyzed the subjective and objective outcomes of these 12 studies and compared them to the results of the NHS to determine optimal management of PCL injuries. Results: Final follow-up times ranged from a mean of 6.2 to 15 years in the nonoperative studies and 6.3 to 12 years in the operative studies. Side-to-side differences in laxity following surgical management ranged from 1.1 to 7 mm on KT-1000 arthrometer testing and 2.8 to 4.7 mm on Telos stress testing. Tegner scores at final follow-up ranged from 6.6 to 7.7 in nonoperative studies and 5.7 to 7.4 in operative studies. International Knee Documentation Committee scores were 73.4, 82.7, and 84 in nonoperative studies and 65 and 87 in the operative studies. Lysholm scores were 85.2 in the nonoperative study and ranged from 81 to 92.1 in operative studies. Osteoarthritis was reported with ranges from 17% to 88% in nonoperative studies and 13.3% to 63.6% in operative studies. Conclusion: We found that the subjective and objective results in the NHS compare favorably to those of outcomes for PCL reconstruction. Unless a technique is found that can completely restore knee stability, it is unlikely that simply reducing posterior laxity will improve outcomes or prevent the development of osteoarthritis

Evaluation of Joint Space Width and Narrowing After Isolated Partial Medial Meniscectomy for Degenerative Medial Meniscus Tears

BACKGROUND: Few studies have evaluated the effect of existing articular cartilage damage and sex on joint space measurements after isolated degenerative medial meniscus tears. PURPOSE: To determine what factors affected joint space width and narrowing in patients after removal of isolated degenerative medial meniscus tears. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: A total of 62 patients (15 women and 47 men) with all ligaments intact, no previous surgery to either knee, and an isolated degenerative medial meniscus tear removed in 1 knee were examined. The mean age at examination was 58.2 years at a mean follow-up of 9.4 years (range, 4-20 years). Subjective results were obtained with the International Knee Documentation Committee (IKDC) knee survey. Radiographs were taken using 45° weightbearing posteroanterior views. Midpoint and perceived minimum joint space width of the medial and lateral compartments of both knees were measured to the nearest 0.1 mm by 2 observers at different times, and they were blinded as to the previous measurements (Pearson intra- and interclass correlations, >0.93). Joint space narrowing was found by calculating the difference in joint space width between knees. Percentage of normal joint space loss was calculated by dividing joint space narrowing by the joint space width in the contralateral knee. Other factors considered were patient sex and Outerbridge grading of articular cartilage. RESULTS: Women had a mean 1.5 mm less normal joint space width than men in the involved and noninvolved knees (P 50% of the normal joint space as measured in the noninjured knee (P = .016). The mean IKDC total score was 66.1 points for women, which was statistically significantly lower than the mean of 82.7 points for men (P < .01). CONCLUSION: Patients undergoing partial medial meniscectomy have greater joint space narrowing and lower subjective scores after surgery if they also have existing Outerbridge grade 3-4 damage. Women have less normal joint space than men, and more women than men experience >50% joint space narrowing after surgery

Precise radial velocities of giant stars. III. Spectroscopic stellar parameters

Context: A radial velocity survey of about 380 G and K giant stars is ongoing at Lick observatory. For each star we have a high signal to noise ratio template spectrum, which we use to determine spectroscopic stellar parameters. Aim: The aim of this paper is to present spectroscopic stellar parameters, i.e. effective temperature, surface gravity, metallicity and rotational velocity for our sample of G and K giant stars. Methods: Effective temperatures, surface gravities and metallicities are determined from the equivalent width of iron lines. Rotational velocities are determined from the full width at half maximum (FWHM) of moderate spectral lines. A calibration between the FWHM and total broadening (rotational velocity and macro turbulence) is obtained from stars in common between our sample and the sample from Gray (1989). Results: The metallicity we derive is essentially equal to the literature values, while the effective temperature and surface gravity are slightly higher by 56 K and 0.15 dex, respectively. Our rotational velocities are comparable with the ones obtained by Gray (1989), but somewhat higher than the ones obtained by de Medeiros & Mayor (1999), consistent with the different diagnostics used. Conclusions: We are able to determine spectroscopic stellar parameters for about 380 G and K giant stars in a uniform way (112 stars are being analysed spectroscopically for the first time). For stars available in the literature, we find reasonable agreement between literature values and values determined in the present work. In addition, we show that the metallicity enhancement of companion hosting stars might also be valid for giant stars, with the planet-hosting giants being 0.13 +/- 0.03 dex (i.e. 35 +/- 10%) more metal-rich than our total sample of stars.Comment: 16 pages, 8 figures, 4 tables, accepted for publication by Astronomy and Astrophysic

Corporate Social Responsibility and Islamic Financial Institutions (IFIs): Management Perceptions from IFIs in Bahrain

Islamic finance is gaining greater attention in the finance industry, and this paper analyses how Islamic financial institutions (IFIs) are responding to the welfare needs of society. Using interview data with managers and content analysis of the disclosures, this study attempts to understand management perceptions of corporate social responsibility (CSR) in IFIs. A thorough understanding of CSR by managers, as evident in the interviews, has not been translated fully into practice. The partial use of IFIs’ potential role in social welfare would add further challenges in the era of financialisation

The SDSS-III Baryon Oscillation Spectroscopic Survey: Quasar Target Selection for Data Release Nine

The SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), a five-year spectroscopic survey of 10,000 deg^2, achieved first light in late 2009. One of the key goals of BOSS is to measure the signature of baryon acoustic oscillations in the distribution of Ly-alpha absorption from the spectra of a sample of ~150,000 z>2.2 quasars. Along with measuring the angular diameter distance at z\approx2.5, BOSS will provide the first direct measurement of the expansion rate of the Universe at z > 2. One of the biggest challenges in achieving this goal is an efficient target selection algorithm for quasars over 2.2 < z < 3.5, where their colors overlap those of stars. During the first year of the BOSS survey, quasar target selection methods were developed and tested to meet the requirement of delivering at least 15 quasars deg^-2 in this redshift range, out of 40 targets deg^-2. To achieve these surface densities, the magnitude limit of the quasar targets was set at g <= 22.0 or r<=21.85. While detection of the BAO signature in the Ly-alpha absorption in quasar spectra does not require a uniform target selection, many other astrophysical studies do. We therefore defined a uniformly-selected subsample of 20 targets deg^-2, for which the selection efficiency is just over 50%. This "CORE" subsample will be fixed for Years Two through Five of the survey. In this paper we describe the evolution and implementation of the BOSS quasar target selection algorithms during the first two years of BOSS operations. We analyze the spectra obtained during the first year. 11,263 new z>2.2 quasars were spectroscopically confirmed by BOSS. Our current algorithms select an average of 15 z > 2.2 quasars deg^-2 from 40 targets deg^-2 using single-epoch SDSS imaging. Multi-epoch optical data and data at other wavelengths can further improve the efficiency and completeness of BOSS quasar target selection. [Abridged]Comment: 33 pages, 26 figures, 12 tables and a whole bunch of quasars. Submitted to Ap

Gekko and black swans: finance theory in UK undergraduate curricula

Despite the current financial crisis, accounting and finance programmes in UK have remained popular. Finance undergraduate teaching in accounting degrees is a significant component of the degree and relies heavily on Modern Finance Theory (MFT). Some of the developments in the finance curricula are critically examined. It is argued that current finance education should become more reflective and more heterodox in approach as the current curricula is biased towards techniques based on neoclassical theory. Suggestions are given for improvement of the curricula which will allow the narrow assumptions of neoclassical theory to be widened. These involve students taking into account not only the structures and patterns of finance but also the processes which are created by human experiences as part of their interactions as well as what helps to make these processes sustainable

The influence of diet and environment on the gut microbial community of field crickets

The extent to which diet and environment influence gut community membership (presence or absence of taxa) and structure (individual taxon abundance) is the subject of growing interest in microbiome research. Here, we examined the gut bacterial communities of three cricket groups: (1) wild caught field crickets, (2) laboratory-reared crickets fed cat chow, and (3) laboratory-reared crickets fed chemically defined diets. We found that both environment and diet greatly altered the structure of the gut bacterial community. Wild crickets had greater gut microbial diversity and higher Firmicutes to Bacteroidetes ratios, in contrast to laboratory-reared crickets. Predictive metagenomes revealed that laboratory-reared crickets were significantly enriched in amino acid degradation pathways, while wild crickets had a higher relative abundance of peptidases that would aid in amino acid release. Although wild and laboratory animals differ greatly in their bacterial communities, we show that the community proportional membership remains stable from Phylum to Family taxonomic levels regardless of differences in environment and diet, suggesting that endogenous factors, such as host genetics, have greater control in shaping gut community membership

Titling community land to prevent deforestation: An evaluation of a best-case program in Morona-Santiago, Ecuador

Assigning land title to collective landholders is one of the primary policies land management agencies use to avoid deforestation worldwide. Such programs are designed to improve the ability of landholders to legally exclude competing users and thereby strengthen incentives to manage forests for long-term benefits. Despite the prevalence of this hypothesis, findings about the impacts of land titling programs on deforestation are mixed. Evidence is often unreliable because programs are targeted according to factors that independently influence the conversion of forests. We evaluate a donor-funded land titling and land management program for indigenous communities implemented in Morona-Santiago, Ecuador. This program offers a close to best case scenario for a land titling program to reduce deforestation because of colonization pressure, availability of payments when titled communities maintain forests, and limited opportunities for commercial agriculture. We match plots in program areas with similar plots outside program areas on covariates that influence the conversion of forests. Based on matched comparisons, we do not find evidence that land titling or community management plans reduced forest loss in the five years following legal recognition. The results call into question land titling as a direct deforestation strategy and suggests land titling is better viewed a precursor to other programs. (C) 2015 The Authors. Published by Elsevier Ltd

Relative clustering and the joint halo occupation distribution of red-sequence and blue-cloud galaxies in COMBO-17

This paper studies the relative spatial distribution of red-sequence and blue-cloud galaxies, and their relation to the dark matter distribution in the COMBO-17 survey as function of scale down to z~1. We measure the 2nd-order auto- and cross-correlation functions of galaxy clustering and express the relative biasing by using aperture statistics. Also estimated is the relation between the galaxies and the dark matter distribution exploiting galaxy-galaxy lensing (GGL). All observables are further interpreted in terms of a halo model. To fully explain the galaxy clustering cross-correlation function with a halo model, we need to introduce a new parameter,R, that describes the statistical relation between numbers of red and blue galaxies within the same halo. We find that red and blue galaxies are clearly differently clustered, a significant evolution of the relative clustering with redshift was not found. There is evidence for a scale-dependence of relative biasing. The relative clustering, the GGL and, with some tension, the galaxy numbers can be explained consistently within a halo model. For the cross-correlation function one requires a HOD variance that becomes Poisson even for relatively small occupancy numbers. For our sample, this rules out with high confidence a "Poisson satellite" scenario as found in semi-analytical models. Red galaxies have to be concentrated towards the halo centre, either by a central red galaxy or by a concentration parameter above that for dark matter.The value of R depends on the presence or absence of central galaxies: If no central galaxies or only red central galaxies are allowed, R is consistent with zero, whereas a positive correlation $R=+0.5\pm0.2$ is needed if both blue and red galaxies can have central galaxies.[ABRIDGED]Comment: 30 pages, 13 figures, accepted by MNRAS, major changes: improved redshift distributions of samples, now comoving number densities of galaxy samples are estimated and fitted by halo-model, correction of wrong confidence limits in Table 2, new figure with Mb-magnitudes of sample

Measures of Galaxy Environment - I. What is "Environment"?

The influence of a galaxy's environment on its evolution has been studied and compared extensively in the literature, although differing techniques are often used to define environment. Most methods fall into two broad groups: those that use nearest neighbours to probe the underlying density field and those that use fixed apertures. The differences between the two inhibit a clean comparison between analyses and leave open the possibility that, even with the same data, different properties are actually being measured. In this work we apply twenty published environment definitions to a common mock galaxy catalogue constrained to look like the local Universe. We find that nearest neighbour-based measures best probe the internal densities of high-mass haloes, while at low masses the inter-halo separation dominates and acts to smooth out local density variations. The resulting correlation also shows that nearest neighbour galaxy environment is largely independent of dark matter halo mass. Conversely, aperture-based methods that probe super-halo scales accurately identify high-density regions corresponding to high mass haloes. Both methods show how galaxies in dense environments tend to be redder, with the exception of the largest apertures, but these are the strongest at recovering the background dark matter environment. We also warn against using photometric redshifts to define environment in all but the densest regions. When considering environment there are two regimes: the 'local environment' internal to a halo best measured with nearest neighbour and 'large-scale environment' external to a halo best measured with apertures. This leads to the conclusion that there is no universal environment measure and the most suitable method depends on the scale being probed.Comment: 14 pages, 9 figures, 1 table, published in MNRA