The invasive marine alga Caulerpa taxifolia was discovered June 12, 2000, in California at Agua Hedionda Lagoon. Due to a 15-year history of spread in the Mediterranean Sea, C. taxifolia had already ...been placed on the US Federal Noxious Weed list in 1999. Awareness of this threat greatly facilitated consensus building and setting clear eradication goals among a large number of state, federal and local agencies as well as private groups and non-governmental organizations (NGOs) that became the 'Southern California Caulerpa Action Team' (SCCAT). Field containment and treatments began 17 days after the discovery due to: (1) timely identification and notification of the infestation; (2) the proactive staff of the San Diego Regional Water Quality Control Board who deemed this invasion tantamount to an 'oil spill', thus freeing up emergency funding; (3) the mobilization of diver crews already working at the site. Three well-integrated components of this rapid response have resulted in an effective eradication program: (a) expertise and knowledge on the biology of C. taxifolia; (b) knowledge on the uses, 'ownership' and characteristics of the infested site; (c) knowledge and experience in the implementation of aquatic plant eradication. Together, with the requisite resources (approximately $US1.2 million per year), this approach has resulted in containment, treatment and excellent progress toward eradication of C. taxifolia. Successful rapid response to other aquatic invasive species will require similar readiness to act, and immediate access to adequate funding.
We question several common elements of conventional descriptions of Early Paleoindian adaptations. Specifically, we examine the presumed scales of residential mobility, the role of high-quality ...lithics in these movements, and the extent to which First Americans hunted large game as a fundamental part of their food-getting activities. We compare the Early Paleoindian data to relevant information on hunting, mobility, and weaponry documented ethnohistorically and ethnographically. We then construct an alternative explanation for the Early Paleoindian record based on the premise that the hunting of large mammals, presumably by men, may have been motivated more by social and political factors than by the need to regularly and reliably provision a family or band with food. By proposing a plausible alternative explanation for the available data, we suggest that there is good reason to think critically about several of the basic components of the conventional view of Early Paleoindian adaptations.
The current study evaluated the reciprocal longitudinal relationship between physical activity (PA) and motor competence (MC) and the potential mediation of cardiorespiratory endurance across 7 ...years.
This was a 7-year longitudinal study, the Copenhagen School Child Intervention Study (CoSCIS), with 3 measuring points mean ages (in years) and respective sample size: 6.75 ± 0.37, n = 696; 9.59 ± 1.07, n = 617; 13.35 ± 0.34, n = 513. PA was assessed using accelerometers. MC was evaluated by the Körperkoordinationstest für Kinder (KTK) test battery. Cardiorespiratory fitness (VO
peak) was evaluated using a continuous running protocol until exhaustion. Structural equation modeling was performed to evaluate the longitudinal associations.
Vigorous PA (VPA) and MC presented reciprocal longitudinal association during the 7-year follow-up (VPA → MC; β = 0.18; 95% CI: 0.10, 0.26; MC → VPA; β = 0.14; 95% CI: 0.08, 0.21). In addition, VO
peak mediated the relationship in both directions (VPA → MC; β = 0.09; 95% CI: 0.06, 0.12; MC → VPA; β = 0.06; 95% CI: 0.03, 0.09).
PA and MC presented a positive reciprocal relationship across childhood through early adolescence and VO
peak mediated the association in both directions. Interventions targeting to increase PA in children and adolescents should also address the development of MC skills because of the clear positive feedback loop between PA and MC.
Archaeological geophysics in Norway - an historical overview and status evaluation The introduction of archaeological geophysics to Norway has been relatively slow and the methodologies employed are ...still very much in their infancy. A recently compiled overview indicates that only about 120 surveys have been conducted in Norway over the last 40 years, which is a relatively low number compared with other countries. In other European countries several hundred surveys are conducted annually and archaeological geophysics is generally considered an integral part of archaeological investigations and evaluations. The article gives a short description of the most commonly used methods in archaeology, and focuses on some of the more important geophysical surveys carried out in Norway. Furthermore, it seeks to explain why the Norwegian archaeological milieu has been reluctant to adopt these methods in their work.
Metabolic rate is a basic individual metric that extends beyond the individual to link the ecology of populations, communities, and ecosystems via its role as a central component of energy budgets. ...Metabolic rates are often measured indirectly by quantifying respiration under simplified, standard laboratory conditions. This approach limits the application of these measurements to a small range of conditions that commonly do not reflect natural field conditions. We measured metabolic rates of the squareback marsh crab Armases cinereum under field conditions. Previous work highlights that movement of individual A. cinereum, especially females, provides a potential spatial subsidy of energy, as individuals consume foods in salt marshes and then transfer the resulting energy to upland forest ecosystems. We show that metabolic rate increases with size for both males and females and that metabolic rates are influenced by temperature and by whether females are vitellogenic. The metabolic rates that we measured more closely approximate field metabolic rates than standard metabolic rates and demonstrate that individual crabs experience high energy expenditures, reducing the amount of energy that may be transferred as a subsidy between marsh and forest as a result of the daily movements of individual crabs. Our measurements are therefore also a key component for the construction of an energy budget for this species.
We show that the flatback marsh crab Armases cinereum has relatively high rates of energy use. This likely limits the ability of this species to act as a vector for energy subsidies between salt marsh and forest habitats, as has previously been hypothesized.
Submersed aquatic plants have a key role in maintaining functioning aquatic ecosystems through their effects on the hydrological regime, sedimentation, nutrient cycling and habitat of associated ...fauna. Modifications of aquatic plant communities, for example through the introduction of invasive species, can alter these functions. In the Sacramento-San Joaquin River Delta, California, a major invasive submersed plant, Brazilian waterweed Egeria densa, has become widespread and greatly affected the functionality of the submersed aquatic plant community. Rapid assessments of the distribution and abundance of this species are therefore crucial to direct management actions early in the season. Given the E. densa bimodal growth pattern (late spring and fall growth peaks), summer assessments of this species may indicate which and where other submersed species may occur and fall assessments may indicate where this and other species may occur in the following spring, primarily because the Delta's winter water temperatures are usually insufficient to kill submersed aquatic plant species. We assessed community composition and distribution in the fall of 2007 and summer of 2008 using geostatistical analysis; and measured summer biomass, temperature, pH, salinity, and turbidity. In the fall of 2007, submersed aquatic plants covered a much higher proportion of the waterways (60.7%) than in the summer of 2008 (37.4%), with a significant overlap between the seasonal distribution of native and non-native species. Most patches were monospecific, and multispecies patches had significantly higher dominance by E. densa, co-occurring especially with Ceratophyllum demersum. As species richness of non-natives increased there was a significant decrease in richness of natives, and of native biomass. Sustained E. densa summer biomass negatively affected the likelihood of presence of Myriophyllum spicatum, Potamogeton crispus, and Elodea canadensis but not their biomass within patches. Depth, temperature and salinity were associated with biomass; however, the direction of the effect was species specific. Our results suggest that despite native and invasive non-native submersed plant species sharing available niches in the Delta, E. densa affects aquatic plant community structure and composition by facilitating persistence of some species and reducing the likelihood of establishment of other species. Successful management of this species may therefore facilitate shifts in existing non-native or native plant species.
Abstract Background Broad diagnostics of respiratory infection by molecular assays has not yet won acceptance due to technical difficulties and high costs. Objectives To evaluate clinical ...applicability of multiplex real-time PCR. Study design An assay targeting influenza virus A (IfA) and B (IfB), parainfluenza 1-3 (PIV), human metapneumovirus (MPV), respiratory syncytial virus (RSV), rhinovirus (RV), enterovirus (EV), adenovirus (AdV), human coronaviruses (229E, OC43, NL63), M. pneumoniae and Ch. pneumoniae was developed and run daily on consecutive clinical nasopharyngeal swab samples. Results An etiology was identified in 48% of the 954 samples, with IfA in 25%, RV in 20%, MPV in 10% and M. pneumoniae in 10% of the positive. By a rational procedure costs could be reduced and the customer price set relatively low (€33 per sample). Conclusion Streamlined testing and cost limitation is achievable and probably critical for implementation of a broad molecular diagnostics of respiratory infections.
Widespread growth of invasive aquatic vegetation is a major stressor to the Sacramento-San Joaquin River Delta, a region of significant recreational, economic, and ecological importance. Total ...invaded area in the Delta is increasing, with the risk of new invasions a continual threat. However, invasive aquatic vegetation in the Delta remains an elusive ecosystem management challenge despite decades of directed scientific research and prioritized policy recognition. In this paper, we summarize the current state of knowledge of the history, status, and potential future directions for coordinated research, management actions, and policy based on topics discussed at symposium head on invasive aquatic vegetation on September 15, 2015. Remote sensing technology, mechanical, chemical, and biological control, as well as community science networks have all been shown to be effective management tools, but overall effectiveness has been hindered by complex regulatory structure, the lack of a consistent monitoring program, regulations that restrict treatments in space and time, and funding cuts. In addition, new management options depend on continued research and development of new active ingredients for chemical control and testing of biological control agents. The ongoing development and implementation of new strategies for adaptive, integrated management of aquatic weeds, using currently-available management tools, new knowledge derived from remote sensing and plant growth models, and an area-wide, ecosystem-based approach, is showing promise to achieve improved management outcomes and enhance protection of the Delta’s water resources.
► A calorimetric approach to cellulase product inhibition has been developed. ► The assay uses unmodified, insoluble cellulose as substrate. ► Glucose- and cellobiose inhibition was quantified for ...five H. jecorina cellulases. ► The strongest inhibition was found for Cel7A/cellobiose and Cel6A/glucose. ► The activity of Cel5A was only weakly affected by the two investigated products.
Product inhibition of cellulolytic enzymes has been deemed a critical factor in the industrial saccharification of cellulosic biomass. Several investigations have addressed this problem using crude enzyme preparations or commercial (mixed) cellulase products, but quantitative information on individual cellulases hydrolyzing insoluble cellulose remains insufficient. Such knowledge is necessary to pinpoint and quantify inhibitory weak-links in cellulose hydrolysis, but has proven challenging to come by. Here we show that product inhibition of mono-component cellulases hydrolyzing unmodified cellulose may be monitored by calorimetry. The key advantage of this approach is that it directly measures the rate of hydrolysis while being essentially blind to the background of added product. We investigated the five major cellulases from Hypocrea jecorina (anamorph: Tricoderma reesei), Cel7A (formerly CBH1), Cel6A (CBH2), Cel7B (EG1), Cel5A (EG2) and Cel12A (EG3), for their sensitivity to the products glucose and cellobiose. The strongest inhibition was found for Cel7A, which showed a 50% activity-loss in 19mM cellobiose (IC50=19mM). The other exoglucanase, Cel6A, was much less inhibited by cellobiose, but showed the highest sensitivity to glucose among all investigated enzymes. The endoglucanases Cel12A and Cel7B were moderately inhibited by cellobiose (IC50=60–80mM), and weakly inhibited by glucose (IC50=350–380mM). The highest resistance to both products was found for Cel5A, which retained about 75% of its activity at the highest investigated concentrations (respectively 65mM cellobiose and 1000mM glucose).
Abstract
Nonlethal injury is a pervasive stress on individual animals that can affect large portions of a population at any given time. Yet most studies examine snapshots of injury at a single place ...and time, making the implicit assumption that the impacts of nonlethal injury are constant. We sampled Asian shore crabs
Hemigrapsus sanguineus
throughout their invasive North American range and from the spring through fall of 2020. We then documented the prevalence of limb loss over this space and time. We further examined the impacts of limb loss and limb regeneration on food consumption, growth, reproduction, and energy storage. We show that injury differed substantially across sites and was most common towards the southern part of their invaded range on the East Coast of North America. Injury also varied idiosyncratically across sites and through time. It also had strong impacts on individuals via reduced growth and reproduction, despite increased food consumption in injured crabs. Given the high prevalence of nonlethal injury in this species, these negative impacts of injury on individual animals likely scale up to influence population level processes (e.g., population growth), and may be one factor acting against the widespread success of this invader.
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