Sustainable use of wildlife: The view from archaeozoology

The concept of “sustainable use” is a polemic, especially when referring to wildlife and other “natural resources.” Claims vary from persistent overuse to traditional practices of sustaining the resource base. Arguments for either side routinely draw from contemporary situations, relying on relatively short time periods. But, if the notion “sustainable” is to be consequential, the period under consideration must be meaningful – claims that trends over a few years or even decades are representative of long-term phenomena are questionable, for they depend on numerous untested, if not untestable, assumptions. Research in anthropology, biology, biological conservation, ecology, policy, restoration ecology, social development, and wildlife management is routinely constrained to relatively short time periods, and such results are of limited value for evaluating sustainable use. Archaeozoology provides unique tools for investigating trends in human-resource relations over periods of centuries and millennia; it is one of the few disciplines explicitly dedicated to the study of material evidence over significant time periods that bears directly on the question of sustainable use. Hence, objective, scientific evaluation of sustainable use must contemplate archaeozoological evidence.Yet, archaeozoology often does not provide definitive answers: it is wrought with fundamental problems in sampling, data gathering, analysis, and interpretation (e.g., varying screen sizes; meta-sampling procedures; comparisons across diverse spatial, temporal, and environmental continua; etc.). Typically data must be evaluated through inference, rather than through direct observations and experiments. Moreover, environmental variation (e.g., climate change, sea level change, tectonic movement, etc.), as well as changes in societies, confounds the interpretation of long-term human–environmental trends. But, those challenges are not unique to archaeozoology, for biological and ecological phenomena are no less subject to multiple sources of environmental and social variation. The difference is that archaeologists are patently cognizant of these sources of variability, and they openly debate them when interpreting data, while in other disciplines these sources of change are routinely ignored. Nonetheless, despite the unique relevance of their work, few archaeozoologists have ventured outside their discipline to engage natural scientists and policy makers in issues of biological conservation and wildlife biology, and particularly the root questions of sustainable use. In addition to considering data and hypotheses regarding long-term prehistoric human–wildlife interactions, it is essential to view this information within broader perspectives, linked to other disciplines as well as to contemporary social and policy issues. Because sustainable use is mandated in international instruments and national policies, the notion has relevance in arenas far beyond academia, where archaeozoologists must be integrated into interdisciplinary teams.     

Characteristics of dynamic postural reactions in the locust hindleg

Summary The use of the locust (Schistocerca americana) hindleg in postural control was examined in animals that stood on a repeatedly swayed vertical substrate. Myograms were recorded from leg muscles and the angle of the femoro-tibial joint was monitored photographically. Two discrete strategies were observed,; in compensatory reactions the hindleg was held in place, while in flexion reactions, the leg was moved, most often to complete flexion of the femoro-tibial joint. Tightly coupled, rhythmic bursting occurred in the flexor and levator muscles of the leg during compensatory reactions. Bursting was initiated repeatedly when the substrate was being pulled away from the animal. Bursting was correlated with subsequent decreases in the rate of change of the femorotibial joint angle. Compensatory and flexion reactions occurred preferentially in different ranges of joint angles: most often, compensatory reactions occurred in the midrange, while flexion reactions were elicited in the extremes of joint angle. These differences may be due to the mechanical advantages of the tibial muscles and the leg may be moved to full flexion because of a locking mechanism of the flexor muscle tendon. These reactions are compared with known reflexes of hindleg proprioceptors and contrasted with similar responses of vertebrates.     

Changing Museum Visitors’ Conceptions of Evolution

We examined whether a single visit to an evolution exhibition contributed to conceptual change in adult (n?=?30), youth, and child (n?=?34) museum visitors?? reasoning about evolution. The exhibition included seven current research projects in evolutionary science, each focused on a different organism. To frame this study, we integrated a developmental model of visitors?? understanding of evolution, which incorporates visitors?? intuitive beliefs, with a model of free-choice learning that includes personal, sociocultural, and contextual variables. Using pre- and post-measures, we assessed how visitors?? causal explanations about biological change, drawn from three reasoning patterns (evolutionary, intuitive, and creationist), were modified as a result of visiting the exhibition. Whatever their age, background beliefs, or prior intuitive reasoning patterns, visitors significantly increased their use of explanations from the evolutionary reasoning pattern across all measures and extended this reasoning across diverse organisms. Visitors also increased their use of one intuitive reasoning pattern, need-based (goal-directed) explanations, which, we argue, may be a step toward evolutionary reasoning. Nonetheless, visitors continued to use mixed reasoning (endorsing all three reasoning patterns) in explaining biological change. The personal, socio-cultural, and contextual variables were found to be related to these reasoning patterns in predictable ways. These findings are used to examine the structure of visitors?? reasoning patterns and those aspects of the exhibition that may have contributed to the gains in museum visitors?? understanding of evolution.     

The mechanism of CD47-dependent killing of T cells: heterotrimeric Gi-dependent inhibition of protein kinase A

CD47 has been implicated in both positive and negative regulation of T cells as well as in T cell death. To clarify the role of CD47 in T cell function, we have studied the mechanism of T cell death in response to CD47 ligands, including mAb 1F7, thrombospondin-1, and a CD47 agonist peptide derived from it. CD47(-/-) Jurkat T cells (JINB8) were resistant to killing by all three ligands, indicating the essential role of CD47. Primary human T cells were also killed by CD47 ligands, but only after activation with anti-CD3. CD47-mediated cell death occurred without active caspases, DNA fragmentation, or Bcl-2 degradation. Pretreatment of Jurkat and primary T cells with pertussis toxin (PTX) prevented CD47-mediated death, indicating the involvement of G((i)alpha). Pretreatment of T cells with 8-bromo cAMP, forskolin, or 3-isobutyl-1-methylxanthine prevented the CD47-mediated apoptosis, and 1F7 dramatically reduced intracellular cAMP levels, an effect reversed with PTX. H89 and protein kinase A (PKA) inhibitor peptide, a specific PKA inhibitor, prevented rescue of T cells by PTX, 8-bromo cAMP, and forskolin, indicating a direct role for one or more PKA substrates. Thus, CD47-mediated killing of activated T cells occurs by a novel pathway involving regulation of cAMP levels by heterotrimeric G((i)alpha) with subsequent effects mediated by PKA.     

Mutations in Smooth Muscle Alpha-Actin (ACTA2) Cause Coronary Artery Disease, Stroke, and Moyamoya Disease, Along with Thoracic Aortic Disease

The vascular smooth muscle cell (SMC)-specific isoform of α-actin (ACTA2) is a major component of the contractile apparatus in SMCs located throughout the arterial system. Heterozygous ACTA2 mutations cause familial thoracic aortic aneurysms and dissections (TAAD), but only half of mutation carriers have aortic disease. Linkage analysis and association studies of individuals in 20 families with ACTA2 mutations indicate that mutation carriers can have a diversity of vascular diseases, including premature onset of coronary artery disease (CAD) and premature ischemic strokes (including Moyamoya disease [MMD]), as well as previously defined TAAD. Sequencing of DNA from patients with nonfamilial TAAD and from premature-onset CAD patients independently identified ACTA2 mutations in these patients and premature onset strokes in family members with ACTA2 mutations. Vascular pathology and analysis of explanted SMCs and myofibroblasts from patients harboring ACTA2 suggested that increased proliferation of SMCs contributed to occlusive diseases. These results indicate that heterozygous ACTA2 mutations predispose patients to a variety of diffuse and diverse vascular diseases, including TAAD, premature CAD, ischemic strokes, and MMD. These data demonstrate that diffuse vascular diseases resulting from either occluded or enlarged arteries can be caused by mutations in a single gene and have direct implications for clinical management and research on familial vascular diseases.     

p38 MAPK inhibitors suppress biomarkers of hypertension end-organ damage,osteopontin and plasminogen activator inhibitor-1

The assessment of target organ damage is important in defining the optimal treatment of hypertension and blood pressure-related cardiovascular disease. The aims of the present study were (1) to investigate candidate biomarkers of target organ damage, osteopontin (OPN) and plasminogen activator inhibitor-1 (PAI-1), in models of malignant hypertension with well characterized end-organ pathology; and (2) to evaluate the effects of chronic treatment with a p38 MAPK inhibitor. Gene expression, plasma concentrations, and renal immunohistochemical localization of OPN and PAI-1 were measured in stroke-prone spontaneously hypertensive rats on a salt–fat diet (SFD SHR-SP) and in spontaneously hypertensive rats receiving N^ω-nitro-L-arginine methyl ester (L-NAME SHR). Plasma concentrations of OPN and PAI-1 increased significantly in SFD SHR-SP and L-NAME SHR as compared with controls, (2.5–4.5-fold for OPN and 2.0–9.0-fold for PAI-1). The plasma levels of OPN and PAI-1 were significantly correlated with the urinary excretion of albumin (p<0.0001). Elevations in urinary albumin, plasma OPN and PAI-1 were abolished by chronic treatment (4–8 weeks) with a specific p38 MAPK inhibitor, SB-239063AN. OPN immunoreactivity was localized predominantly in the apical portion of tubule epithelium, while PAI-1 immunoreactivity was robust in glomeruli, tubules and renal artery endothelium. Treatment with the p38 MAPK inhibitor significantly reduced OPN and PAI-1 protein expression in target organs. Kidney gene expression was increased for OPN (4.9- and 7.9-fold) and PAI-1 (2.8- and 11.5-fold) in SFD SHR-SP and L-NAME SHR, respectively. In-silico pathway analysis revealed that activation of p38 MAPK was linked to OPN and PAI-1 via SP1, c-fos and c-jun; suggesting that these pathways may play an important role in p38 MAPK-dependent hypertensive renal dysfunction. The results suggest that enhanced OPN and PAI-1 expression reflects end-organ damage in hypertension and that suppression correlates with end-organ protection regardless of overt antihypertensive action.     

Association of the cyclic AMP chemotaxis receptor with the detergent-insoluble cytoskeleton of Dictyostelium discoideum

Treatment of 6-h differentiated Dictyostelium discoideum cells with the nonionic detergent Triton X-100 dissolves away membranes and soluble components, as judged by marker enzyme distributions, leaving intact a cytoskeletal residue that contains approximately 10% of the cell protein and 50% of the actin. Nitrobenzooxadiazo-phallacidin staining for F-actin and electron microscopy of detergent-extracted whole-mounts indicate that the cytoskeletons retain the size and shape of intact cells and contain F-actin in cortical meshworks. The cytoskeletons contain little if any remaining membrane material by morphological criteria, and the plasma membrane enzymes cyclic nucleotide phosphodiesterase and alkaline phosphatase are absent from the insoluble residue, which retains only 15% of the membrane concanavalin A-binding glycoproteins. This detergent-insoluble residue retains a specific [3H]cAMP-binding site with the nucleotide specificity, rapid kinetics and approximate affinity of the cAMP receptor on intact cells. Upon detergent extraction of cells, the number of cAMP-binding sites increases 20-70%. The binding site is attached to the insoluble residue whether or not the cAMP receptor is occupied at the time of detergent addition. The pH dependence for recovery of the insoluble cAMP-binding site is much sharper than that on intact cells or membranes with an optimum at pH 6.1. Conditions of pH and ionic composition that lead to disruption of the cytoskeleton upon detergent treatment also result in the loss of cAMP binding. During differentiation, the detergent- insoluble cAMP binding increases in parallel with cell surface cAMP receptors and chemotaxis to cAMP.     

鼠李糖乳杆菌LV108及其发酵乳免疫调节作用的比较

目的 探讨鼠李糖乳杆菌LV108及其发酵乳对免疫抑制小鼠免疫功能的调节作用。 方法 将BALB/c小鼠随机分为5组,每组10只,即空白组(正常小鼠)、模型组(免疫抑制小鼠)、药物组(免疫抑制小鼠食物中添加左旋咪唑)、LV108菌悬液组(免疫抑制小鼠食物中添加LV108菌悬液)和LV108发酵乳组(免疫抑制小鼠食物中添加LV108发酵乳),除空白组外其余组构建免疫抑制小鼠模型。干预4周后,分别测定各组小鼠体质量和脏器指数,血清中白细胞介素2(IL2)、肿瘤坏死因子α(TNFα)和免疫球蛋白G(IgG)含量,血清溶血素含量、耳肿胀度和肝、脾巨噬细胞吞噬能力。 结果 相比模型组,LV108菌悬液组和LV108发酵乳组小鼠体质量增长速度、脏器指数、血清IL2与IgG水平、血清溶血值、耳肿胀度和巨噬细胞吞噬能力显著升高(均P结论 LV108菌体及发酵乳对免疫抑制小鼠具备较全面的免疫调节作用,均可提高小鼠的自身免疫力;LV108发酵乳对小鼠的免疫调节作用强于LV108菌体。