A quantitative method for measuring regional economic resilience to the great recession

Regional economic resilience can be defined as an economy’s ability to withstand and recover quickly from shocks. The ability to measure resilience is necessary to developing our understanding of what influences resilience. In this paper, we develop a new, two‐dimensional quantitative measure of resilience using observed differences between expected and actual employment in a region following a shock and distinguish the response to the shock from random variation. We demonstrate one application of this metric to US county‐level employment data to compare county responses to the 2007–2009 national recession and discuss how different regions of the United States responded to the shock of the Great Recession in terms of resilience.     

The effects of lead on algae

Lead inhibits respiration and photosynthesis in Phaeodactylum. In cells treated for 24 h with PbCl₂ (10 mg 1^?1), photosynthesis is completely suppressed, while respiration is reduced to 25%. A lower concentration, 1.0 mg 1^?1, permits photosynthesis at 75% of the control rate, respiration being virtually unaffected. The vital activities of cells treated for 48 h or 72 h are progressively more inhibited: concentrations of PbCl₂ as low as 0.1 mg 1^?1 reduce photosynthesis and respiration by 25 to 50%.     

Cross-reactivity of a monoclonal antibody with bovine, equine, ovine, and porcine peripheral blood B lymphocytes

Ficoll-thrombin purified suspensions of bovine, equine, ovine, and porcine peripheral blood lymphocytes were fractionated on nylon-wool columns. The percentages of surface immunoglobulin (SIg+)-bearing lymphocytes in the adherent (B-cell enriched) and nonadherent (T-cell enriched) fractions were determined for individual animals using fluorescein isothiocyanate conjugated species-specific anti-Ig sera. Subsequently, the human leukocyte antigen DR-specific monoclonal antibody, H4, was tested for its ability to recognize a cross-reactive antigen on the fractionated lymphocytes, using the microcytotoxicity technique. The H4 plus complement killed a percentage of lymphocytes equivalent to the percentage of SIg+ lymphocytes in the adherent and nonadherent fractions. In a parallel experiment, a 2 fluorochrome technique was used to visualize bovine lymphocytes that were SIg+ and H4+. Lymphocytes that were SIg+ also stained with ethidium bromide (orange fluorescence) after complement-mediated cytotoxicity. Seemingly, H4 recognizes an evolutionarily conserved major histocompatibility complex encoded class-II-like determinant on the B lymphocytes of cattle, horses, sheep, and swine.     

Monoclonal antibodies that distinguish bovine T and B lymphocytes

The specificities of three monoclonal antibodies (MAbs) were investigated using microcytotoxicity, fluorescence microscopy and laser flow cytometry (LFC) techniques. By microcytotoxicity, bovine thymocytes (n = 4) were estimated to be 85% B26A+, 4% TH21A+, and 1% H4+. Nylon wool enriched peripheral blood T lymphocytes (n = 3) were 90% B26A+, 10% TH21A+ and 10% H4+. Adherent B cell enriched fractions (n = 3) were 10% B26A+, 90% TH21A+ and 90% H4+. The two fluorochrome method was used to simultaneously identify lymphocytes that were sIg+ and MAb+. In these experiments, 92% of all sIg+ cells were H4+. An identical result was obtained for TH21A. 85% of all sIg- cells were B26A+. Using LFC, the mean percentages of sIg+, H4+ and TH21A+ PBL (n = 5) were not significantly different. B26A recognized a significantly greater population of cells, equivalent to the expected percentage of T lymphocytes. LFC also revealed two relatively discrete sizes of B26A+ PBL. The larger population overlapped the size range in which sIg+, H4+, TH21A+ PBL were found. The more numerous smaller B26A+ PBL were in a size range in which few sIg+, H4+ and TH21A+ PBL were found. In a study of MAb reactions with PBL of 185 cows, it was shown that in 92% of the animals H4 and TH21A were positively correlated (r = +.93), when H4 and TH21A were negatively correlated with B26A (r = -.94 and r = -.92, respectively). These correlation coefficients indicate a converse relationship between B26A and both H4 and TH21A. The remaining 8% of the animals were heterogeneous in their expression of the H4 and TH21A markers but not the B26A marker. These results provide strong evidence that: 1) B26A is a pan-T lymphocyte MAb in cattle, 2) a small but significant degree of heterogeneity exists in the expression of the epitopes recognized by H4 and TH21A. However, both MAbs recognize all B lymphocytes of most individuals, and 3) using a variety of immunological methods these three MAbs can now reliably be used to assay bovine T and B lymphocytes.     

Dynamics of mammalian chromosome evolution inferred from multispecies comparative maps

The genome organizations of eight phylogenetically distinct species from five mammalian orders were compared in order to address fundamental questions relating to mammalian chromosomal evolution. Rates of chromosome evolution within mammalian orders were found to increase since the Cretaceous-Tertiary boundary. Nearly 20% of chromosome breakpoint regions were reused during mammalian evolution; these reuse sites are also enriched for centromeres. Analysis of gene content in and around evolutionary breakpoint regions revealed increased gene density relative to the genome-wide average. We found that segmental duplications populate the majority of primate-specific breakpoints and often flank inverted chromosome segments, implicating their role in chromosomal rearrangement.