Industry Effects on Firm and Segment Profitability Forecasting

Academics and practitioners have long recognized the importance of a firm’s industry membership in explaining its financial performance. Yet, contrary to conventional wisdom, recent research shows that industry-specific profitability forecasting models are not better than economy-wide models. The objective of this paper is to further explore this result and to provide insights into when and why industry-specific profitability forecasting models are useful. We show that industry-specific forecasts are significantly more accurate in predicting profitability for single-segment firms and, to some extent, for business segments. For multiple-segment firms, the aggregation of segment-level data for external reporting of firm-level financials obliterates the industry effects of their segments

Weak commutation relations of unbounded operators: nonlinear extensions

We continue our analysis of the consequences of the commutation relation [S,T]=\Id, where $S$ and $T$ are two closable unbounded operators. The {\em weak} sense of this commutator is given in terms of the inner product of the Hilbert space \H where the operators act. {We also consider what we call, adopting a physical terminology}, a {\em nonlinear} extension of the above commutation relations

Lower Semi-frames, Frames, and Metric Operators

This paper deals with the possibility of transforming a weakly measurable function in a Hilbert space into a continuous frame by a metric operator, i.e., a strictly positive self-adjoint operator. A necessary condition is that the domain of the analysis operator associated with the function be dense. The study is done also with the help of the generalized frame operator associated with a weakly measurable function, which has better properties than the usual frame operator. A special attention is given to lower semi-frames: indeed, if the domain of the analysis operator is dense, then a lower semi-frame can be transformed into a Parseval frame with a (special) metric operator

Developmental genetic mechanisms of evolutionary tooth loss in cypriniform fishes

The fossil record indicates that cypriniform fishes, a group including the zebrafish, lost oral teeth over 50 million years ago. Despite subsequent diversification of feeding modes, no cypriniform has regained oral teeth, suggesting the zebrafish as a model for studying the developmental genetic basis of evolutionary constraint. To investigate the mechanism of cypriniform tooth loss, we compared the oral expression of seven genes whose mammalian orthologs are involved in tooth initiation in the zebrafish and the Mexican tetra, Astyanax mexicanus, a related species retaining oral teeth. The most significant difference we found was an absence in zebrafish oral epithelium of expression of dlx2a and dlx2b, transcription factors that are expressed in early Astyanax odontogenic epithelium. Analysis of orthologous genes in the Japanese medaka (Oryzias latipes) and a catfish (Synodontis multipunctatus) suggests that expression was lost in cypriniforms, rather than gained in Astyanax. Treatment of Astyanaxwith an inhibitor of Fibroblast growth factor (Fgf) signaling produced a partial phenocopy of the zebrafish oral region, in that oral teeth, and expression of d1x2a and d1x2b, were lost, whereas shh and pitx2, genes whose expression is present in zebrafish oral epithelium, were unaffected. We hypothesize that a loss of Fgf signaling to oral epithelium was associated with cypriniform tooth loss

Non-linear unbalanced Bessel beams: Stationary conical waves supported by nonlinear losses

Nonlinear losses accompanying Kerr self-focusing substantially impacts the dynamic balance of diffraction and nonlinearity, permitting the existence of localized and stationary solutions of the 2D+1 nonlinear Schrodinger equation which are stable against radial collapse. These are featured by linear conical tails that continually refill the nonlinear, central spot. An experiment shows that the discovered solution behaves as strong attractor for the self-focusing dynamics in Kerr media.Comment: 4 pages, 2 figures; experimental verification adde

A novel role for granzymes in anti-tumor immunity

The cytotoxic properties of granzymes are well established, though recent publications suggest additional roles for granzymes in immunity. We demonstrated that granzymes can act as regulators of cross-presentation by dendritic cells by inducing critical “eat-me” signals on the dying tumor cell, resulting in efficient phagocytosis of cell-associated tumor antigen

Fabrication and characterization of alginate-keratin based composite microspheres containing bioactive glass for tissue engineering applications

3D cell encapsulation within hydrogels has attracted more and more attention in tissue engineering applications because hydrogels provide a hydrated environment closely mimicking the in vivo environment for cell and tissue growth1. This present study considers the fabrication of alginate-keratin based composite microspheres containing bioactive glass (BG) of 45S5 composition for cell encapsulation. We propose the use of alginate di-aldehyde (ADA) synthesized via periodate oxidation of alginate to enhance the biodegradability of alginate, and the incorporation of keratin into the alginate based hydrogel to improve cellular interaction of the hydrogel. Keratins extracted from wool contain cell adhesive peptide sequences including RGD (arginine-glycine-aspartic acid), and LDV (leucine-aspartic acid-valine)2. BG particles, well known for promoting calcium phosphate deposition, were incorporated into the microspheres to enhance osseointegration3. The microspheres were prepared via a pressure-driven extrusion technique. Weight loss, protein release measurements, and FTIR spectroscopy of the fabricated microspheres were carried out. The morphology and microstructure of the microspheres were investigated by light microscopy and scanning electron microscopy (SEM), respectively. The results demonstrated that the composition of the hydrogels had a significant effect on their physical properties. Biological properties of ADA-keratin based microspheres were evaluated by encapsulating MG-63 osteosarcoma cells into the microspheres. Cell viability of MG-63 cells in ADA-keratin-1%BG hydrogels was found to be comparable to that of alginate-keratin and ADA-keratin after culturing for 21 days. The results proved that such novel composite hydrogel might be a promising material for biofabrication in bone healing approaches. Please click Additional Files below to see the full abstract

Mechanism For Copper(II)-Mediated Disaggregation Of A Porphyrin J-Aggregate

J-aggregates of anionic meso-tetrakis(4-sulfonatophenyl)porphyrin form at intermediate pH (2.3–3.1) in the presence of NiSO₄ or ZnSO₄ (ionic strength, I.S. = 3.2 M). These aggregates convert to monomeric porphyrin units via metallation with copper(II) ions. The kinetics for the disassembly process, as monitored by UV/vis spectroscopy, exhibits zeroth-order behavior. The observed zeroth-order rate constants show a two-term dependence on copper(II) ion concentrations: linear and second order. Also observed is an inverse dependence on hydrogen ion concentration. Activation parameters have been determined for the disassembly process leading to ΔH^≠ = (+163 ± 15) kJ·mol⁻¹ and ΔS^≠ = (+136 ± 11) J·K⁻¹. A mechanism is proposed in which copper(II) cation is in pre-equilibrium with a reactive site at the rim of the J-aggregate. An intermediate copper species is thus formed that eventually leads to the final metallated porphyrin either through an assisted attack of a second metal ion or through a direct insertion of the metal cation into the macrocycle core

Are Giant Pandas (Ailuropoda Melanoleuca) Averse to Inequity?

Inequity aversion, a negative response to situations of unequal reward distribution, is a cognitive trait usually seen in social species. This capacity is thought to regulate cooperative relationships in intelligent, cognitively flexible animals. Giant pandas are a unique case in that wild populations are characterized as nonsocial, however captive populations are socially housed until sexual maturity. This allows for the study of a nonsocial species in a social context and thus the assessment of socio-cognitive flexibility across evolutionarily distant taxa. Here, we assessed whether the giant panda (Ailuropoda melanoleuca) displays inequity aversion by testing ten juveniles living at the Chengdu Research Base of Giant Panda Breeding in China. Traditionally in an equity aversion paradigm, the quality or quantity of the reward offered to the subject is less than that offered to the partner. For this study, effort inequity was used instead due to the limited variety in the giant pandas’ diet as well as to further verify this less studied kind of inequity. We tested pandas in an effort inequity paradigm by assessing their responses to several testing conditions: social inequity (two pandas, unequal effort, equal reward), social equity (two pandas, equal effort, equal reward), non-social inequity (one panda, unequal effort, equal reward) and non-social equity (one panda, equal effort, equal reward). In the social inequity condition, the partner was given a piece of apple for free before the subject was cued to perform a hind-leg stand in order to receive a piece of apple. Performance was recorded as positive responses to a cue and latency to complete the trained behavior, a hind-leg stand. Rates of frustration-related behaviors displayed during sessions were also recorded to make judgments on the pandas’ emotional state in reaction to the situation. We found no statistical significance across conditions, although one panda’s performance on inequity trials was suggestive of inequity aversion. Further testing is required to elucidate the context necessary to elicit this response as well as what individual differences might be involved that influence an individual’s propensity to display inequity aversion