Woodland clearance in the Mesolithic: the social aspects.

Did Mesolithic people regard the woodland as a wilderness or park? Previous models have portrayed the hunter-gatherers of the Mesolithic as in tune with nature and making use of clearings to attract game. Using equally valid analogies, the authors propose a more hostile landscape that was conceived and managed with clearings and paths to help allay its menacing character

Syngenic Adipose-Derived Stem/Stromal Cells Delivered in Decellularized Adipose Tissue Scaffolds Enhance In Vivo Tissue Regeneration Through Host Cell Recruitment

Decellularized adipose tissue (DAT) represents a promising adipogenic bioscaffold for applications in soft tissue augmentation or reconstruction. With the goal of investigating the role of syngeneic donor adipose-derived stem/stromal cells (ASCs) and host myeloid cells during in vivo adipose tissue regeneration, transgenic reporter mouse strains were used to track these cell populations within ASC-seeded and unseeded DAT scaffolds. Donor ASCs were obtained from dsRed transgenic mice. These cells were shown to express characteristic cell surface markers, and multilineage differentiation capacity was confirmed. To facilitate cell tracking, DAT scaffolds were subcutaneously implanted into MacGreen mice in which myeloid cells express enhanced green fluorescent protein (EGFP). ASC-seeded DAT scaffolds augmented total cell recruitment as well as adipogenesis, and influenced EGFP+ myeloid cell infiltration kinetics within the implants. The donor dsRed+ ASCs were retained within the DAT scaffolds up to 8 weeks post-implantation, and did not contribute directly to the newly formed adipocytes

Annual Report Readership: A Study of an Agricultural Supply Cooperative

Recent corporate collapses have focussed attention on the (un)reliability of financial information. However, although the agricultural sector, which is significant globally, is run primarily using the cooperative form, there is scant research on these users' perception of financial information. Therefore this paper examines members' readership and understanding of the annual reports of a large, fertiliser cooperative. The findings show that there is a lack of readership of the annual report, due to a lack of understanding and a lack of time. A minority of non-readers trust directors to "do a good job". Preparers of information should focus on making reports more user-friendly and evidence suggests that financial information could be released more strategically using other sources of communication, namely other print media and the internet.cooperatives, annual reports, readership, understanding, Agribusiness,

Financial services used by small businesses: evidence from the 1998 survey of small business finances

Using newly available data from the 1998 Survey of Small Business Finances, this article offers preliminary findings regarding the characteristics of small businesses in the United States and their use of credit and other financial services. The main goals of the survey are to provide information on credit accessibility for small businesses, their use of financial services, and the sources of those services. The survey also provides a general-purpose database that can be used to study small business financing. Preliminary findings suggest that although the financial landscape has changed markedly since the previous survey in 1993, financing patterns and the use of particular suppliers have not.Small business ; Financial services industry

Historical diversification of birds in Northwestern South America: A molecular perspective on the role of vicariant events

Studies of South American biodiversity have identified several areas of endemism that may have enhanced historical diversification of South American organisms. Hypotheses concerning the derivation of birds in the Choco area of endemism in northwestern South America were evaluated using protein electrophoretic data from 14 taxonomically diverse species groups of birds. Nine of these groups demonstrated that the Choco area of endemism has a closer historical relationship to Central America than to Amazonia, a result that is consistent with phytogeographic evidence. Within species groups, genetic distances between cis-Andean (east of the Andes) and trans-Andean (west of the Andes) taxa are, on average, roughly twice that between Choco and Central American taxa. The genetic data are consistent with the hypotheses that the divergence of most cis-Andean and trans-Andean taxa was the result of either the Andean uplift fragmenting a once continuous Amazonian-Pacific population (Andean Uplift Hypothesis), the isolation of the two faunas in forest refugia on opposite sides of the Andes during arid climates (Forest Refugia Hypothesis), or dispersal of Amazonian forms directly across the Andes into the trans-Andean region (Across-Andes Dispersal Hypothesis). Disentangling these hypotheses is difficult due to the complexity of the Andean uplift and to the scant geologic and paleoclimatic information that elucidates diversification events in northwestern South America. Regarding the divergence of cis- and trans-Andean taxa, the genetic, geologic, and paleoclimatic data allow weak rejection of the Andean Uplift Hypothesis and weak support for the Forest Refugia and Andean Dispersal Hypotheses. The subsequent diversification of Choco and Central American taxa was the result of Pleistocene forest refugia, marine transgressions, or parapatric speciation

Evidence for a dynamic phase transition in [Co/Pt]_3 magnetic multilayers

A dynamic phase transition (DPT) with respect to the period P of an applied alternating magnetic field has been observed previously in numerical simulations of magnetic systems. However, experimental evidence for this DPT has thus far been limited to qualitative observations of hysteresis loop collapse in studies of hysteresis loop area scaling. Here, we present significantly stronger evidence for the experimental observation of this DPT, in a [Co(4 A)/Pt(7 A)]_3-multilayer system with strong perpendicular anisotropy. We applied an out-of-plane, time-varying (sawtooth) field to the [Co/Pt]_3 multilayer, in the presence of a small additional constant field, H_b. We then measured the resulting out-of-plane magnetization time series to produce nonequilibrium phase diagrams (NEPDs) of the cycle-averaged magnetization, Q, and its variance, Var(Q), as functions of P and H_b. The experimental NEPDs are found to strongly resemble those calculated from simulations of a kinetic Ising model under analagous conditions. The similarity of the experimental and simulated NEPDs, in particular the presence of a localized peak in the variance Var(Q) in the experimental results, constitutes strong evidence for the presence of this DPT in our magnetic multilayer samples. Technical challenges related to the hysteretic nature and response time of the electromagnet used to generate the time-varying applied field precluded us from extracting meaningful critical scaling exponents from the current data. However, based on our results, we propose refinements to the experimental procedure which could potentially enable the determination of critical exponents in the future.Comment: substantial revision; 26 pages, 9 figures; to appear in Phys. Rev.

The role of quantum fluctuations in the optomechanical properties of a Bose-Einstein condensate in a ring cavity

We analyze a detailed model of a Bose-Einstein condensate trapped in a ring optical resonator and contrast its classical and quantum properties to those of a Fabry-P{\'e}rot geometry. The inclusion of two counter-propagating light fields and three matter field modes leads to important differences between the two situations. Specifically, we identify an experimentally realizable region where the system's behavior differs strongly from that of a BEC in a Fabry-P\'{e}rot cavity, and also where quantum corrections become significant. The classical dynamics are rich, and near bifurcation points in the mean-field classical system, the quantum fluctuations have a major impact on the system's dynamics.Comment: 11 pages, 11 figures, submitted to PR