Is the Genetic Code Optimized for Resource Conservation?

The causes and consequences of the nonrandom structure of the standard genetic code (SGC) have been of long-standing interest. A recent study reported that mutations in present-day protein-coding sequences are less likely to increase proteomic nitrogen and carbon uses under the SGC than under random genetic codes, concluding that the SGC has been selectively optimized for resource conservation. If true, this finding might offer important information on the environment in which the SGC and some of the earliest life forms evolved. However, we here show that the hypothesis of optimization of a genetic code for resource conservation is theoretically untenable. We discover that the aforementioned study estimated the expected mutational effect by inappropriately excluding mutations lowering resource consumptions and including mutations involving stop codons. After remedying these problems, we find no evidence that the SGC is optimized for nitrogen or carbon conservation.     

Micro Resource公司开发低成本培养微藻的装置

风险企业微资源（Micro Resource）公司（东京千代田,真松久人社长）持续从事着微藻培养装置的研究开发。其目标是要开发低成本培养3万种微藻的装置。     

Resource Security Impacts Men’s Female Breast Size Preferences

It has been suggested human female breast size may act as signal of fat reserves, which in turn indicates access to resources. Based on this perspective, two studies were conducted to test the hypothesis that men experiencing relative resource insecurity should perceive larger breast size as more physically attractive than men experiencing resource security. In Study 1, 266 men from three sites in Malaysia varying in relative socioeconomic status (high to low) rated a series of animated figures varying in breast size for physical attractiveness. Results showed that men from the low socioeconomic context rated larger breasts as more attractive than did men from the medium socioeconomic context, who in turn perceived larger breasts as attractive than men from a high socioeconomic context. Study 2 compared the breast size judgements of 66 hungry versus 58 satiated men within the same environmental context in Britain. Results showed that hungry men rated larger breasts as significantly more attractive than satiated men. Taken together, these studies provide evidence that resource security impacts upon men’s attractiveness ratings based on women’s breast size.     

Impacts of Biotic Resource Enrichment on a Predator–Prey Population

The environmental carrying capacity is usually assumed to be fixed quantity in the classical predator–prey population growth models. However, this assumption is not realistic as the environment generally varies with time. In a bid for greater realism, functional forms of carrying capacities have been widely applied to describe varying environments. Modelling carrying capacity as a state variable serves as another approach to capture the dynamical behavior between population and its environment. The proposed modified predator–prey model is based on the ratio-dependent models that have been utilized in the study of food chains. Using a simple non-linear system, the proposed model can be linked to an intra-guild predation model in which predator and prey share the same resource. Distinct from other models, we formulate the carrying capacity proportional to a biotic resource and both predator and prey species can directly alter the amount of resource available by interacting with it. Bifurcation and numerical analyses are presented to illustrate the system’s dynamical behavior. Taking the enrichment parameter of the resource as the bifurcation parameter, a Hopf bifurcation is found for some parameter ranges, which generate solutions that posses limit cycle behavior.     

What Sources Are Natural Resource Managers Using to Make Decisions?

Natural resource management is more effective when it includes collaboration among numerous stakeholders who bring multiple perspectives to the decision-making process. In particular, many individuals and organizations (e.g., The Wildlife Society) have advocated for decisions to be science-based as a means for improving management outcomes. But there has been little research evaluating the sources, science-based or otherwise, used by natural resource agencies to support decision-making at the state-level within the United States. We surveyed state natural resource agency personnel in all 50 states to assess the sources of information used to make management decisions and the factors that influenced selection of the sources. Approximately 60% of respondents reported using ≥3 different source types when making recommendations. Existing management plans, the peer-reviewed scientific literature, and expert opinion were the most frequently used sources. Perception of source relevance was the most frequent predictor of source use, and the number of management plans a manager had previously written positively predicted the use of management plans, expert opinion, and personal experiences. Ninety percent of respondents reported that increased use of the peer-reviewed literature would or might improve management recommendations. Aspects of academic and agency cultures influenced which articles or journals were used to make recommendations. Our findings indicate managers support the use of peer-reviewed literature as an important component of management decision-making; however, if the goal is to improve the flow of information between scientists and managers, researchers should publish in journals that are readily accessible to managers and present results in a way that clearly articulates relevance to management decisions. © 2021 The Wildlife Society.     

Resource tracking in marine parasites: going with the flow?

Understanding how diversity interacts with energy supply is of broad ecological interest. Most studies to date have investigated patterns within trophic levels, reflecting a lack of food webs which include information on energy flow. We added parasites to a published marine energy‐flow food web, to explore whether parasite diversity is correlated with energy flow to host taxa. Parasite diversity was high with 36 parasite taxa affecting 40 of the 51 animal taxa. Adding parasites increased the number of trophic links per species, trophic link strength, connectance, and food chain lengths. There was evidence of an asymptotic relationship between energy flowing through a food chain and parasite diversity, although there were clear outliers. High parasite diversity was associated with host taxa which were highly connected within the food web. This suggests that energy flow through a taxon may favour parasite diversity, up to a maximal value. The evolutionary and energetic basis for that limitation is of key interest in understanding the basis for parasite diversity in natural food webs and thus their role in food web dynamics.     

Introduction of Standard for the operation of European Biological Resource Centers

(Continued)The equipment and environment in the premises must conform to European legislation meeting quality standards as well as health and safely requirements. The following conditions must be met:Ⅰ. BRC laboratories are clean and well itⅡ. No source of excessive or unusual microbial contamination is introducedⅢ. Adequate bench and storage space is provided, consistent with the type and volume of work,Ⅳ. An appropriate containment facility is available to protect the work and worker from potential release of aerosols containing microorganisms or hazardous chemicals.     

Sex Allocation in California Oaks: Trade-Offs or Resource Tracking?

Trade-offs in sex resource allocation are commonly inferred from a negative correlation between male and female reproduction. We found that for three California oak species, aboveground annual net productivity (ANP) differences among individuals were primarily correlated with water availability and soil fertility. Reproductive biomass increased with ANP, but the relative allocation to reproduction was constant, indicating that reproduction tracked productivity, which in turn tracked site quality. Although there was a negative correlation between male and female reproduction, this was not the result of a resource investment trade-off, but rather a byproduct of the positive correlation between female reproductive biomass and ANP combined with the greater overall resource allocation to female, compared to male, function. Thus, we reject the hypothesis of a trade-off between these key life-history components within individuals of these species. For long-lived individuals, a plastic resource tracking response to environmental fluctuations may be more adaptive than directly linking life-history traits through trade-offs.     

Resource Capture by Localized Root Proliferation: Why Do Plants Bother?

Using data from a well-known, published experiment [Drew (1975)TheNew Phytologist75: 479–490], the potential exploitationof locally available nutrients by barley roots is calculated.Local proliferation of lateral roots does not necessarily achievesignificantly greater exploitation of mobile soil resourceslike nitrate, but it does for less mobile ones such as phosphate.Despite this, the magnitude of the proliferative response isas great to locally available nitrate as it is to phosphate.This implies an ‘over-production’ of roots in responseto localized nitrate availability, prompting a re-evaluationof the nature and implications of the response mechanism(s)of roots to soil heterogeneity. Hordeum vulgare; barley; carbon; heterogeneity; lateral root; nitrate; localized nutrient supply; phosphate; proliferation; root     

Clonal Growth in Plants in Relation to Resource Heterogeneity:Foraging Behavior

In nature, essential resources for organisms, such as food for animals and light, water and nutrients for plants, are usually heterogeneously distributed, even at very small scale. As a result, all organisms, particularly plants mostly sessile, have a difficulty in acquiring essential resources from their environments. Animals express various types of foraging behavior to capture heterogeneously distributed essential foods. Clonal growth ( a vegetative reproductive process where by more than one individual of identical genetic composition is formed ) provides clonal plant not only with many "mouths" at different spatial positions, but also with a large spacial movability. As a clonal plant grows in environments characterized by a small-scale resource heterogeneity, its inter ramet connection permits a resource-sharing among the connected tamers. In addition, it may also allow certain ramets to respond locally and non-locally to resousce heterogeneity. This may lead to a division of labor among the connected ramets and a selective placement of ramets in favorable micro-habitats. Together these may enhance exploitation of resource heterogeneity by clonal plants, and in turn greatly contribute to maintenance or improvement of fitness. Such a behavior of clonal plants, expressed in heterogeneous environments, is to a large extent comparable to that of animals. Therefore, it has been considered as foraging behavior in clonal plants. More recently, it has been observed that phenotypic plasticity of clonal plants, which is relevant to foraging behavior, varies among species, types of genet architecture as well as among types of plants habitats. Foraging in clonal plants and its diversity have been receiving increasingly intensive investigations.     

Influence of Nematodes on Resource Utilization by Bacteria—an in vitro Study

The positive influence of bacterial feeding nematodes on bacterial mediated processes such as organic matter mineralization and nutrient cycling is widely accepted, but the mechanisms of these interactions are not always apparent. Both transport of bacteria by nematodes, and nutritional effects caused by nematode N excretion are thought to be involved, but their relative importance is not known because of the difficulties in studying these interactions in soil. We developed a simple in vitro assay to study complex nematode/bacterial interactions and used it to conduct a series of experiments to determine the potential influence of nematode movement and nutritional effects on bacterial resource use. The system used bacterial feeding and nonfeeding insect parasitic nematodes, and luminescent bacteria marked with metabolic reporter genes. Both nutritional enhancement of bacterial activity and bacterial transport were observed and we hypothesize that in nature, the relative importance of transport is likely to be greater in bulk soil, whereas nematode excretion may have greater impact in the rhizosphere. In both cases, the ability of nematodes to enhance bacterial resource utilization has implications for soil components of biogeochemical cycling.     

Resource Defence or Exploded Lek? – A Question of Perspective

It becomes increasingly obvious that animal mating systems cannot be classified into distinct categories, but transitions between mating system classes are continuous. Positioning a certain mating system at this continuum is often not straightforward, however. Depending on which characteristic is considered, a mating system may end up at very different positions on this gradient. Here, we explore the potential conflict between mating system classifications that may arise when they are based on different criteria by investigating the mating system of the cichlid fish Simochromis pleurospilus in which males defend small patches of homogeneously distributed food resources (turf algae) vigorously against food competitors, but they allow specific females to use them. We hypothesized that male defence may generate high‐quality feeding patches serving to attract females, and hence male territoriality constitutes a form of courtship. Our field data show that males selectively allow approximately one‐third of the visiting females to feed on their territory and that females preferentially feed in male territories and usually sample several territories successively. As males protect food patches against other algae grazers and guard females from harassment by food competitors, females gain nutritional benefits from visiting male territories. Hence, males appear to generate essential resources for females, which is the key feature of resource‐defence mating systems, although the distributions of resources and of males and females are characteristics of an exploded lek.     

Resource allocation: a conflict in the fig/fig wasp mutualism?

Conflicts of interest are omnipresent between mutualist species. In the monoecious fig/pollinator wasp mutualism, each female flower produces either a seed or a pollinator offspring (which has fed on a single seed). Pollen from a syconium (i.e. fig, a closed urn-shaped inflorescence) is only dispersed by female pollinator offspring born in this syconium. Thus the fig tree is selected to produce both seed and pollinator offspring whereas for the pollinator there is no short term advantage in seed production. Using controlled pollination experiments (pollen injection, and foundress introduction), we show that 1) The relative proportion of seeds and pollinator offspring produced (i.e., the effective allocation between female and male function) depends mainly on the number of foundresses that entered the syconium. 2) Many female flowers within every syconium mature neither a seed nor a wasp (from 25% to 33%). 3) All the female flowers within a syconium that are not vacant at maturity have the potential to produce a seed, and at least 80% of them can produce a pollinator. Several hypotheses concerning mechanisms that govern the partitioning between seed and wasp production are discussed, and their evolutionary consequences are considered.     

Territorial behavior in Southeast Asian langurs: Resource defense or mate defense?

Between-group antagonism or territoriality in primates may serve two different but compatible functions: resource defense or mate defense. Females are expected to be involved more strongly in the first, males in the second. The resource defense hypothesis predicts that home range overlap should decrease as defensibility and population density increase, and that females should be involved in hostile between-group interactions. The mate defense hypothesis predicts that between-group relations should be hostile and that males should take the primary role in antagonistic encounters. In a comparative study of 12 populations of 6 Presbytis species in Southeast Asia, we found support for the mate defense hypothesis; only males produce loud calls, between-group antagonism is entirely a male affair, and neither defensibility nor population density determine spatial exclusivity or the level of antagonism. We discuss the differences between our findings and traditional interpretations of territorial behavior.     

Bismuth and Silver in Cosmetic Products: A Source of Environmental and Resource Concern?

Bismuth (Bi) and silver (Ag) are used in increasing amounts and are consequently being emitted from various sources and showing high accumulation rates in soils when sewage sludge is applied on arable land. This study aimed to analyze the amounts of Bi and Ag in three cosmetic products (foundation, powder, and eye shadow) in order to study the flows in urban wastewater in Stockholm, Sweden. Analyses showed that Bi was present in very high concentrations (7,000 to 360,000 milligrams per kilogram) in one third of the analyzed foundation and powder samples, whereas Ag concentrations all were below the detection limit. These cosmetic products explained approximately 24% of the measured total Bi amounts per year reaching the WWTP (wastewater treatment plant), making cosmetics a major Bi source, whereas for Ag the corresponding contribution was <0.1% of the measured annual Ag amounts. The results were roughly adapted for Europe and the United States, estimating the Bi flows from cosmetics to WWTPs. On a global scale, these flows correspond to a non‐negligible part of the world Bi production that, every year, ends up in sewage sludge, limiting the reuse of a valuable metal resource. From an environmental and resource perspective, foundations and powder products should be considered as significant sources of measured Bi amounts in sludge. This large Bi flow must be considered as unsustainable. For Ag, however, the three analyzed cosmetic products are not a significant source of the total Ag load to WWTPs.