Common Core Themes in Geomorphic, Ecological, and Social Systems

Core themes of geomorphology include: open systems and connectivity; feedbacks and complexity; spatial differentiation of dominant physical processes within a landscape; and legacy effects of historical human use of resources. Core themes of ecology include: open systems and connectivity; hierarchical, heterogeneous, dynamic, and context-dependent characteristics of ecological patterns and processes; nonlinearity, thresholds, hysteresis, and resilience within ecosystems; and human effects. Core themes of environmental governance include: architecture of institutions and decision-making; agency, or ability of actors to prescribe behavior of people in relation to the environment; adaptiveness of social groups to environmental change; accountability and legitimacy of systems of governance; allocation of and access to resources; and thresholds and feedback loops within environmental policy. Core themes common to these disciplines include connectivity, feedbacks, tipping points or thresholds, and resiliency. Emphasizing these points of disciplinary overlap can facilitate interdisciplinary understanding of complex systems, as well as more effective management of landscapes and ecosystems by highlighting drivers of change within systems. We use a previously published conceptual framework to examine how these core themes can be integrated into interdisciplinary research for human–landscape systems via the example of a river.     

Insights from life history theory for an explicit treatment of trade‐offs in conservation biology

As economic and social contexts become more embedded within biodiversity conservation, it becomes obvious that resources are a limiting factor in conservation. This recognition is leading conservation scientists and practitioners to increasingly frame conservation decisions as trade‐offs between conflicting societal objectives. However, this framing is all too often done in an intuitive way, rather than by addressing trade‐offs explicitly. In contrast, the concept of trade‐off is a keystone in evolutionary biology, where it has been investigated extensively. I argue that insights from evolutionary theory can provide methodological and theoretical support to evaluating and quantifying trade‐offs in biodiversity conservation. I reviewed the diverse ways in which trade‐offs have emerged within the context of conservation and how advances from evolutionary theory can help avoid the main pitfalls of an implicit approach. When studying both evolutionary trade‐offs (e.g., reproduction vs. survival) and conservation trade‐offs (e.g., biodiversity conservation vs. agriculture), it is crucial to correctly identify the limiting resource, hold constant the amount of this resource when comparing different scenarios, and choose appropriate metrics to quantify the extent to which the objectives have been achieved. Insights from studies in evolutionary theory also reveal how an inadequate selection of conservation solutions may result from considering suboptimal rather than optional solutions when examining whether a trade‐off exits between 2 objectives. Furthermore, the shape of a trade‐off curve (i.e., whether the relationship between 2 objectives follows a concave, convex, or linear form) is known to affect crucially the definition of optimal solutions in evolutionary biology and very likely affects decisions in biodiversity conservation planning too. This interface between evolutionary biology and biodiversity conservation can therefore provide methodological guidance to support decision makers in the difficult task of choosing among conservation solutions. Percepciones de la Teoría de Historia de Vida para una Tratamiento Explícito de las Compensaciones en la Biología de la Conservación     

Mesocosm and in situ observations of the burrowing shrimp Calocaris templemani (Decapoda: Thalassinidea) and its bioturbation activities in soft sediments of the Laurentian Trough

In vivo observations in laboratory mesocosms and aquaria, accompanied with in situ photographic surveys, have shown that the burrowing shrimp Calocaris templemani has a significant impact on bottom sediment dynamics and geochemistry in the St. Lawrence Estuary. This burrowing shrimp establishes and maintains complex semi-permanent burrows made up of several interconnected, ‘U-shaped’ galleries with generally four or more openings to the sediment surface. In the Estuary, at 345 m depth, Calocaris average density was estimated at 3.4 individuals m^?2. Observed individual burrows reached a maximum volume of 0.54 L. C. templemani displaces this volume of mostly anoxic sediments from the subsurface layers (down to 15 cm) to the sediment surface, thereby obscuring some of the natural stratification patterns. With an estimated turnover rate of about 8 L m^?2 year^?1 of sediment, our calculations suggest that over a period of about 18.75 years, all the sediment to a depth of 15 cm will have been reworked by C. templemani alone.     

Street floods in Metro Manila and possible solutions

Urban floods from thunderstorms cause severe problems in Metro Manila due to road traffic. Using Light Detection and Ranging (LiDAR)-derived topography, flood simulations and anecdotal reports, the root of surface flood problems in Metro Manila is identified. Majority of flood-prone areas are along the intersection of creeks and streets located in topographic lows. When creeks overflow or when rapidly accumulated street flood does not drain fast enough to the nearest stream channel, the intersecting road also gets flooded. Possible solutions include the elevation of roads or construction of well-designed drainage structures leading to the creeks. Proposed solutions to the flood problem of Metro Manila may avoid paralyzing traffic problems due to short-lived rain events, which according to Japan International Cooperation Agency (JICA) cost the Philippine economy 2.4 billion pesos/day.     

Cellular and molecular mechanisms of embryonic haemangiogenesis and lymphangiogenesis

Vascular diseases are the leading cause of morbidity and mortality in developed nations. Therapeutic haemangiogenesis and lymphangiogenesis may present a chance for curative intervention. Recently we have learned that physiologic and pathologic angiogenesis in the human adult are controlled by molecules that are already functioning during embryogenesis, and the lessons we can learn from studying embryos may be useful for future clinical studies. Here we review cellular and molecular mechanisms of embryonic haemangiogenesis and lymphangiogenesis. The focus lies on the endothelial cell and the surrounding peri-endothelial cells, the growth factors and receptors that control their development, proliferation, maintenance, regression and differentiation. Our rapidly expanding knowledge of the molecules expressed in endothelial cells justifies expanded functional studies in future     

Value of maternal serum unconjugated oestriol measurement in prenatal screening for Down's syndrome

We compared the medical and financial cost-effectiveness of prenatal serum screening for Down's syndrome using maternal age, serum alpha-fetoprotein and human chorionic gonadotrophin with and without the use of unconjugated oestriol. The use of unconjugated oestriol is medically more cost-effective than screening without it at all levels of detection. The actual performance depends on whether gestational age is estimated using ‘dates’ or an ultrasound scan. At a detection rate of 60 per cent, the proportion of unaffected fetal losses per case diagnosed at amniocentesis is about 22 per cent less if gestational age is estimated using dates (time since the first day of the last menstrual period) and about 47 per cent less if it is based on an ultrasound scan examination. At this detection rate, the inclusion of unconjugated oestriol increases costs by about £2k per case diagnosed (£36k instead of £34k) if gestational age is estimated using dates, but it is no more expensive if gestational age is measured from an ultrasound scan examination (indeed, it is more cost-effective at detection rates above 60 per cent). Since there is little change in the financial cost with the inclusion of unconjugated oestriol, for the improved medical performance of screening, it is worthwhile including it in the screening test.     

Variability in host plant chemistry: behavioural responses and life-history parameters of the Colorado potato beetle (Leptinotarsa decemlineata)

Summary. Many studies investigating effects of plant chemicals on herbivore performance have reported contradictory results, perhaps because of possible interaction between different chemicals. Also, a herbivore’s performance is not necessarily consistent with its food or oviposition preference. Our aim was to investigate simultaneously antibiosis (larval growth and survival) and antixenosis (oviposition and feeding preferences) responses in herbivore to three plant chemicals, of which one is expected to have positive and two are expected to have negative effects. Antibiosis was measured by correlating the nitrogen and glycoalkaloid levels in host plants to the survival and adult size of Leptinotarsa decemlineata, by rearing larvae on whole plants of three potato varieties. Although host plants differed in their glycoalkaloid levels, survival rate and adult body size did not differ among beetles reared on different potato varieties. This suggests that beetles are quite robust for differences in both foliar α-chaconine and foliar α-solanine content. However, differences in antixenosis were found although they could not be directly predicted from the leaf chemistry. Females preferred to lay their eggs on the variety with high α-solanine content (Nevsky) towards which males showed a tendency to feeding preference. Overall, our results confirm that beetles are well adapted to the chemical defences of potato plants as potato varieties did not significantly affect beetle performance, but differences in oviposition preference may still result in major differences in the amount of damage inflicted on plants in the fields.