Time Variation of Liquidity in the Private Real Estate Market: An Empirical Investigation

This paper characterizes the behavior of and evaluates competing explanations for time variation in private real estate market liquidity documented in Fisher et al. (2003). In the first, sellers base their estimates of value on observations of signals from the market, but the presence of noise means a change in signal is not fully reflected in sellers?updated value estimates. The second incorporates the option value of waiting, or opportunity cost of not transacting, recently introduced by Krainer (2001) and Novy-Marx (2004), into seller’s optimal valuation strategy. In the third, we allow for the possibility of investors who are not fully rational in the sense that they trade on market sentiment and we link market-wide liquidity to investor sentiment with higher liquidity being due to the presence of irrationally over-optimistic traders. In this model measures of aggregate liquidity act as an indicator of the relative presence (or absence) of sentiment-based traders in the market place and therefore the divergence of asset price from fundamental value. Empirical findings are generally consistent with models of optimal valuation with rational updating and provide support for the opportunity cost approach.

Development of a biaxial compression device for biological samples: preliminary experimental results for a closed cell foam

Biological tissues are subjected to complex loading states in vivo and in order to define constitutive equations that effectively simulate their mechanical behaviour under these loads, it is necessary to obtain data on the tissue's response to multiaxial loading. Single axis and shear testing of biological tissues is often carried out, but biaxial testing is less common. We sought to design and commission a biaxial compression testing device, capable of obtaining repeatable data for biological samples. The apparatus comprised a sealed stainless steel pressure vessel specifically designed such that a state of hydrostatic compression could be created on the test specimen while simultaneously unloading the sample along one axis with an equilibrating tensile pressure. Thus a state of equibiaxial compression was created perpendicular to the long axis of a rectangular sample. For the purpose of calibration and commissioning of the vessel, rectangular samples of closed cell ethylene vinyl acetate (EVA) foam were tested. Each sample was subjected to repeated loading, and nine separate biaxial experiments were carried out to a maximum pressure of 204 kPa (30 psi), with a relaxation time of two hours between them. Calibration testing demonstrated the force applied to the samples had a maximum error of 0.026 N (0.423% of maximum applied force). Under repeated loading, the foam sample demonstrated lower stiffness during the first load cycle. Following this cycle, an increased stiffness, repeatable response was observed with successive loading. While the experimental protocol was developed for EVA foam, preliminary results on this material suggest that this device may be capable of providing test data for biological tissue samples. The load response of the foam was characteristic of closed cell foams, with consolidation during the early loading cycles, then a repeatable load-displacement response upon repeated loading. The repeatability of the test results demonstrated the ability of the test device to provide reproducible test data and the low experimental error in the force demonstrated the reliability of the test data

Successful treatment of a guitarist with a finger joint injury using instrument-assisted soft tissue mobilization: a case report

Finger injuries are common and can greatly affect a musician's quality of life. A 55-year-old man, who had injured the proximal interphalangeal joint of the left index finger 6 months prior to any intervention, was treated with a manual therapy approach incorporating instrument-assisted soft tissue mobilization (IASTM). Initial examination findings included self-reported pain and functional limitations and physical impairments that significantly impeded his ability to play the acoustic guitar. He was treated once a week for 6 weeks with IASTM, joint mobilization, therapeutic exercise, and ice massage. Additionally, a home exercise program and self-care instructions were provided. The patient gained positive outcomes with improvements in pain (Numerical Pain Rating Scale while playing the guitar: initial 5/10, discharge 1/10) and function (Disability Arm Shoulder Hand Sports-Performing Arts Optional Module: initial 75; discharge 6·25), each reaching a minimum clinically important difference. Importantly, he was able to play the guitar with minimal to no pain as desired. Physical measures also improved, including an immediate gain in finger range of motion with IASTM alone. Manual therapy approaches integrating IASTM may provide an effective conservative treatment strategy for patients with finger/hand conditions in the performing arts and other patient populations

Optimizing Software Team Performance with Cultural Differences

Software development is primarily a team task that requires a high degree of coordination among team members. Prior research has indicated that the composition of team member traits such as personality and culture can influence the performance of software teams. However, this line of research does not give practical guidance on how to build teams with personnel constraints. Some research has built teams by starting with personality. However, cultural traits—which are also known to influence team performance—have not been examined in the same manner. This research, therefore, builds upon this stream by: 1) examining the effects of Hofstede’s latest six-dimensional model of national culture, 2) segmenting potential software team members into distinct cultural clusters, and 3) testing the outcomes of teams built upon homogeneous versus heterogeneous cultural compositions over time. Our results indicate that—consistent with prior research—homogenous team compositions are initially better for performance. However, this effect reverses over time, and ultimately heterogenous team compositions are superior

The mechanical response of the ovine lumbar anulus fibrosus to uniaxial, biaxial and shear loads

Analytical and computational models of the intervertebral disc (IVD) are commonly employed to enhance understanding of the biomechanics of the human spine and spinal motion segments. The accuracy of these models in predicting physiological behaviour of the spine is intrinsically reliant on the accuracy of the material constitutive representations employed to represent the spinal tissues. There is a paucity of detailed mechanical data describing the material response of the reinforced­ground matrix in the anulus fibrosus of the IVD. In the present study, the ‘reinforced­ground matrix’ was defined as the matrix with the collagen fibres embedded but not actively bearing axial load, thus incorporating the contribution of the fibre-fibre and fibre-matrix interactions. To determine mechanical parameters for the anulus ground matrix, mechanical tests were carried out on specimens of ovine anulus, under unconfined uniaxial compression, simple shear and biaxial compression. Test specimens of ovine anulus fibrosus were obtained with an adjacent layer of vertebral bone/cartilage on the superior and inferior specimen surface. Specimen geometry was such that there were no continuous collagen fibres coupling the two endplates. Samples were subdivided according to disc region - anterior, lateral and posterior - to determine the regional inhomogeneity in the anulus mechanical response. Specimens were loaded at a strain rate sufficient to avoid fluid outflow from the tissue and typical stress-strain responses under the initial load application and under repeated loading were determined for each of the three loading types. The response of the anulus tissue to the initial and repeated load cycles was significantly different for all load types, except biaxial compression in the anterior anulus. Since the maximum applied strain exceeded the damage strain for the tissue, experimental results for repeated loading reflected the mechanical ability of the tissue to carry load, subsequent to the initiation of damage. To our knowledge, this is the first study to provide experimental data describing the response of the ‘reinforced­ground matrix’ to biaxial compression. Additionally, it is novel in defining a study objective to determine the regionally inhomogeneous response of the ‘reinforced­ground matrix’ under an extensive range of loading conditions suitable for mechanical characterisation of the tissue. The results presented facilitate the development of more detailed and comprehensive constitutive descriptions for the large strain nonlinear elastic or hyperelastic response of the anulus ground matrix

Factors Influencing the Green House Gas Footprint of US Dairy Farms

Environmental Economics and Policy, Livestock Production/Industries,

Quintessence and variation of the fine structure constant in the CMBR

We study dependence of the CMB temperature anisotropy spectrum on the value of the fine structure constant $\alpha$ and the equation of state of the dark energy component of the total density of the universe. We find that bounds imposed on the variation of $\alpha$ from the analysis of currently available CMB data sets can be significantly relaxed if one also allows for a change in the equation of state.Comment: 5 pages, 3 figures. Several references added and a few minor typos corrected in the revised versio

Using the gut microbiota as a novel tool for examining colobine primate GI health

Primates of the Colobinae subfamily are highly folivorous. They possess a sacculated foregut and are believed to rely on a specialized gut microbiota to extract sufficient energy from their hard-to-digest diet. Although many colobines are endangered and would benefit from captive breeding programs, maintaining healthy captive populations of colobines can be difficult since they commonly suffer from morbidity and mortality due to gastrointestinal (GI) distress of unknown cause. While there is speculation that this GI distress may be associated with a dysbiosis of the gut microbiota, no study has directly examined the role of the gut microbiota in colobine GI health. In this study, we used high-throughput sequencing to examine the gut microbiota of three genera of colobines housed at the San Diego Zoo: doucs (Pygathrix) (N=7), colobus monkeys (Colobus) (N=4), and langurs (Trachypithecus) (N=5). Our data indicated that GI-healthy doucs, langurs, and colobus monkeys possess a distinct gut microbiota. In addition, GI-unhealthy doucs exhibited a different gut microbiota compared to GI-healthy individuals, including reduced relative abundances of anti-inflammatory Akkermansia. Finally, by comparing samples from wild and captive Asian colobines, we found that captive colobines generally exhibited higher relative abundances of potential pathogens such as Desulfovibrio and Methanobrevibacter compared to wild colobines, implying an increased risk of gut microbial dysbiosis. Together, these results suggest an association between the gut microbiota and GI illness of unknown cause in doucs. Further studies are necessary to corroborate these findings and determine cause-and-effect relationships. Additionally, we found minimal variation in the diversity and composition of the gut microbiota along the colobine GI tract, suggesting that fecal samples may be sufficient for describing the colobine gut microbiota. If these findings can be validated in wild individuals, it will facilitate the rapid expansion of colobine gut microbiome research

Carbon-Carbon bond forming reactions of organotransition metal enolate complexes

Abstract -Metal enolates play an important role in stereoselective organic synthesis. Their chemistry is affected profoundly by the metal counterion associated with the enolate fragment. In order to expand the potential of replacing main group with transition metal moieties in such species, methods have been developed for the synthesis of a number of stable, characterizable "late" transition metal ql-(C)-enolate complexes having the general structure LM-CH2COR (M = Mo, W, Re). The chemistry of these materials (e.g., functional transformations of the organic carbonyl group, transfer of the enolate moietry to organic substrates such as aldehydes and alkynes) has been investigated. The scope and mechanisms of the enolate reactions will be discussed in detail. The reaction of organic enolates with carbon electrophiles (e.g., alkyl halides, organic carbonyl compounds) gives rise to compounds containing new carbon-carbon bonds; reaction with heteroatom electrophiles results in the formation of oxidized products? There has been much interest recently in developing methods for carrying out these transformations with high stereoselectivity.3 Historically, most enolate research has focused on salts involving alkali metal anions. More recently, research efforts have been extended to enolates associated with organic cations, main group metals, and transition metals. In the transition metal area, enolates involving the so-called "early" metals (to the left of chromium, molybdenum and tungsten) have seen extensive investigationi4 in general these complexes have 0-bonded structures A in Scheme 1. This paper describes the synthesis and chemistry of middle-and late transition metal enolates, which have seen less investigation. It was our hope that such species would be more likely to have Cbound structure B, and also to react with both electrophilic and non-electrophilic species (e.g., by insertion rather than nucleophile-electrophile mechanisms). SYNTHESIS, CHARACTERIZATION AND FUNCTIONAL GROUP TRANSFORMATIONS OF TUNGSTEN AND MOLYBDENUM ENOLATES The well-known nucleophilic anionic metal salts5 Na[(qS-C5R5)(C0)3M] (M = Mo, W, R=H, Me), on treatment with a-chloroketones and esters, provide good yields of enolates 1 -8, as shown in Scheme 2. These are thermally stable complexes that may be isolated by conventional chromatographic and recrystallization methods; they have been characterized fully by elemental analysis and spectroscopic techniques. Preparation of these materials on a multi-gram scale in a one-pot procedure is possible by treatment of W(CO)6 or Mo(C0)6 with NaCp, followed by addition of the a-chlorocarbonyl compound to the resulting metal anion solution. The stability of the tungsten-carbon bond in tungsten ester enolates, fiist suggested several years ago by the work of Green and his coworkers6, has allowed us to carry out a wide range of transformations on the organic carbonyl group. Thus the reactions shown in Scheme 3 proceed in good yield, and lead to stable tungsten enolates containing ester, amide and even carboxylic acid and acid chloride functionality