High Resource Availability Research Articles

Persistence of the plains mouse, Pseudomys australis, with cattle grazing is facilitated by a diet dominated by disturbance-tolerant plants

Abstract A suite of dryland mammals rely on refuges for long-term persistence during alternating cycles of low and high resource availability. Refuges are small, discrete areas into which populations contract during the lengthy dry periods that characterize dryland environments. Little is known about the characteristics of a location that make it functional as a refuge. Similarly, no information exists on how grazing-facilitated landscape modification affects small mammal refuges. To examine these questions, we assessed diet at refuge sites across the low phase (“bust”) of the population cycle of the plains mouse (Pseudomys australis), a threatened, refuge-using rodent coexisting with extensive cattle production in Australia’s drylands. The species has a varied diet dominated by species of grasses and forbs (mostly seeds) with a small proportion of invertebrates. Most of the plants consumed are shallow-rooted and short-lived species that should germinate in response to small rainfall events. Coexistence with cattle production is likely to be possible because grazing-tolerant plants are a dominant component of the diet. Our findings provide a plausible explanation for the persistence of P. australis with cattle production in dryland Australia, which should be further investigated to develop management strategies that will enable continued coexistence. This investigation should be extended to consider other refuge-using species of small mammal in pastoral systems.

High resource availability and lack of competition have increased population of a meso-carnivore—a case study of Golden Jackal in Keoladeo National Park, India

The dynamic relationship between a species and availability of its food resource is one of the important subjects in ecology due to its universal existence and importance. We estimated the density of golden jackal (Canis aureus), assessed the food profile, and reported the food resource availability and use in Keoladeo National Park (KNP). We used distance sampling to estimate the density of golden jackal and its prey species. Scat analysis was adapted to assess the food profile of jackal. The estimated density of golden jackal is 14.84 individuals/km2. Scat analysis showed equal dominance of plant and animal matter in their diet. Remains of nilgai, rodents, chital, and feral cattle frequently occurred in the scat. The presence of wide array of food items in the diet of golden jackal ascertains its generalist habit. Among prey species, the estimated density of chital is the highest (52.37/km2) followed by feral cattle (33.66/km2). The total biomass estimate of prey species is 10,892.68 kg/km2. The ungulate species contributed a total biomass of 4833.88 kg/km2. The feral cattle alone contributed biomass density of 6058.80 kg/km2. The present study reveals highest density of golden jackal ever reported from any protected area around the world, and also lack of any major competitor and high food resource availability has led to a several fold increase in the population size of golden jackal in a span of 3 decades.

Inter-annual and inter-individual variations in survival exhibit strong seasonality in a hibernating rodent.

Most research on the demography of wild animal populations has focused on characterizing the variation in the mortality of organisms as a function of intrinsic and environmental characteristics. However, such variation in mortality is difficult to relate to functional life history components (e.g. reproduction, dispersal, hibernation) due to the difficulty in monitoring biological processes at a sufficiently fine timescale. In this study, we used a 10-year individual-based data set with an infra-annual timescale to investigate both intra- and inter-annual survival patterns according to intrinsic and environmental covariates in an introduced population of a small hibernating rodent, the Siberian chipmunk. We compared three distinct periods related to particular life history events: spring reproduction, summer reproduction and hibernation. Our results revealed strong interactions between intrinsic and temporal effects. First, survival of male chipmunks strongly decreases during the reproduction periods, while survival is high and equal between sexes during hibernation. Second, the season of birth affects the survival of juveniles during their first hibernation, which does not have long-lasting consequences at the adult stage. Third, at an inter-annual scale, we found that high food resource availability before hibernation and low chipmunk densities specifically favour subsequent winter survival. Overall, our results confirm that the well-known patterns of yearly and inter-individual variation of mortality observed in animals are themselves strongly variable within a given year, suggesting that they are associated with various functional components of the animals' life history.

Natural stands diversity and population structure of Lophira lanceolata Tiegh. ex Keay, a local oil tree species in Burkina Faso, West Africa

Non Timber Forest Products play an important role as source of food and income generation in developing countries. In Burkina Faso, many wild tree species provide various useful products, among them the local oil tree, Lophira lanceolata which occurs in the western part of the country. This study aimed at assessing the habitat diversity and population structure of L. lanceolata’s natural stands according to land cover types. Two sites were considered: Banfora, where the use value of fruits is unknown and Orodara, where fruits are exploited for oil production. A stratified and oriented sampling scheme based on the occurrence of L. lanceolata and land cover was applied using rectangular plots of 50 m × 20 m. Phytosociological and quantitative inventories were carried out to assess the woody species diversity of stands and L. lanceolata population structure, respectively. Species diversity indices, structural parameters were computed and analyses of variance, Chi square test were performed to compare sites according to land cover types. The results showed high woody species diversity associated with L. lanceolata stands (H = 3.2–3.6). The densities of L. lanceolata ranged between 94 and 280 trees per hectare, with significant differences between land cover types and sites. The population pattern showed a good regeneration potential and high resource availability. L. lanceolata was fairly resilient to human pressure and tended to recolonize disturbed lands. With a high potential for sustainable management, L. lanceolata is a promising NTFP species which can contribute to improve the local and national economy.

The effects of resource availability and relationship status on women's preference for facial masculinity in men: An eye-tracking study

Previous research has demonstrated that perceived availability of environmental resources affects the mate choice of females. However, it is unclear whether women's partnership status influences the effects of environmental circumstances on masculinity preference. Further, the role of environmental scarcity on women's gaze patterns when evaluating male faces has not been investigated. The current study investigated how relationship status and environmental factors affected women's gaze patterns and preference towards masculinised and feminised male faces. Twenty-two participants in a long-term romantic relationship, and 26 who were single, were primed with either a high (‘wealthy’) or low (‘scarcity’) resource availability scenario. They then completed a facial masculinity/femininity preference task while eye-gaze behaviour was measured. Women in a relationship (but not single women) had an increased preference towards masculine faces in the scarcity condition, compared to the wealthy condition; this preference was also reflected in eye gaze behaviour. In contrast, single women had longer first fixations on feminine rather than masculine faces when evaluating them as long-term partners in the wealthy condition, but no overt preference for either face type. These findings reveal the importance of taking women's relationship status into account in investigations of the role of environmental influences on masculinity preferences.

人工林の価値向上に対する中小規模な木材の流通・販売システムの有用性

The purpose of this study is to verify utility of small/medium scale system of wood distribution and marketing on the value improvement of planted forests. The research results are following: In the central part of Hyogo pref., there are 2 cases picked up. In the case of “SHISONOMORINOKI” project, the system is collaboration among companies. The reason why this area is being largest concentrated place of wood buisinesses in Hyogo pref.. The information sharing between main constituents is managed at wood-processing plant of their associations, and the price of stumpage that had possibility to lead to sustainable forest resources management maintained. In the business scale, it was limited that influence to local forestry. In addition, it was substantially confirmed that substitution for advantage of the conventional wood distribution. In the another case of “SOUND WOOD(s)” project, the system is that the wood coordinator and forest owners play key role. The reason why this area is having high forest resource availability and high management will of the forest owners. Flow of information is managed by wood coordinator and the price of stumpage is fixed at a high price than that of “SHISONOMORINOKI”. Although the business scale is very small. In addition, it was substantially confirmed that substitution for advantage of the conventional wood distribution. As a result, problem solving and to substituting for advantage of conventional wood distribution were substantially confirmed with both examples, besides the business scale. And the utility as the wood distribution and marketing system which contribute to the value improvement of planted forest was confirmed. In both examples, those business scale is small. But they raise value of the wood resources by corresponding to tenderhearted consumer needs. I think it is one route to the value improvement of the local planted forest to build complemental relations between small/medium scale systems which raise value of the wood and large-scale systems which solve quantitative problem of forest resource management. Also, I think it is important that people who link the distribution from the upper part to the lower part for possibility of the system development in other areas. They have rich information about each stage of wood distribution and have technique to draw value of the wood.

Seasonality in marine ecosystems: Peruvian seabirds, anchovy, and oceanographic conditions

In fluctuating environments, matching breeding timing to periods of high resource availability is crucial for the fitness of many vertebrate species, and may have major consequences on population health. Yet, our understanding of the proximate environmental cues driving seasonal breeding is limited. This is particularly the case in marine ecosystems, where key environmental factors and prey abundance and availability are seldom quantified. The Northern Humboldt Current System (NHCS) is a highly productive, low-latitude ecosystem of moderate seasonality. In this ecosystem, three tropical seabird species (the Guanay Cormorant Phalacrocorax bougainvillii, the Peruvian Booby Sula variegata, and the Peruvian Pelican Pelecanus thagus) live in sympatry and prey almost exclusively on anchovy, Engraulis ringens. From January 2003 to December 2012, we monitored 31 breeding sites along the Peruvian coast to investigate the breeding cycle of these species. We tested for relationships between breeding timing, oceanographic conditions, and prey availability using occupancy models. We found that all three seabird species exhibited seasonal breeding patterns, with marked interspecific differences. Whereas breeding mainly started during the austral winter/early spring and ended in summer/early fall, this pattern was stronger in boobies and pelicans than in cormorants. Breeding onset mainly occurred when upwelling was intense but ecosystem productivity was below its annual maxima, and when anchovy were less available and in poor physiological condition. Conversely, the abundance and availability of anchovy improved during chick rearing and peaked around the time of fledging. These results suggest that breeding timing is adjusted so that fledging may occur under optimal environmental conditions, rather than being constrained by nutritional requirements during egg laying. Adjusting breeding time so that fledglings meet optimal conditions at independence is unique compared with other upwelling ecosystems and could be explained by the relatively high abundances of anchovy occurring throughout the year in the NHCS.

Availability and use of neighborhood resources by older people with osteoarthritis: Results from the European Project on OSteoArthritis

This study examines the availability and use of neighborhood resources in relation to clinical lower limb osteoarthritis (LLOA) in older participants from six European countries. Of the 2757 participants (65–85 years), 22.7% had LLOA. Participants with LLOA made more use of places to sit (OR=2.50; CI: 1.36–4.60 in the UK), and less use of parks and walking areas (OR=0.30; CI: 0.12–0.75 in Sweden), compared to participants without LLOA, particularly in countries with high availability of resources. The results suggest that specific features of the environment impact the use of neighborhood resources by older adults with LLOA.

When Love Is in the Air: Understanding Why Dogs Tend to Mate when It Rains.

Seasonality of reproduction is observed in many species of organisms, across taxa, and is influenced by both biotic and abiotic factors. While such seasonality is easy to understand in temperate species exposed to extreme climates, it is more difficult to explain in the tropics. In many tropical species offspring are born during the season of high precipitation, which also coincides with high resource availability. Interestingly, in India, free-ranging dogs seem to mate, and not whelp, when it rains—an observation that cannot be explained by the resource abundance hypothesis. We carried out an extensive study to identify the mating seasons of free-ranging dogs, and observed a strong correlation between both the incidence and frequency of mating related behaviours of dogs, and precipitation levels. There are two clear mating seasons, of which the primary mating season coincides with the monsoon (rainy season) and the secondary mating season coincides with the nor’westerlies in this part of India. We speculate that this strong correlation is an effect of chemistry, rather than biology. While male dogs can mate round the year, females come into estrous seasonally. In the urban environment, dogs are exposed to a lot of olfactory noise, which can dilute the signal present in sex pheromones of the females in heat. A shower leads to increased humidity and reduced temperature of the air, leading to intensification of pheromone signals that trigger a sexual response in the dogs.

Do trees flower longer in the city? A comparison of flowering eucalyptus trees in streets, remnants and continuous forest and their association with nectarivorous birds

Human-dominated environments are often subjected to increased nutrient and moisture regimes which have the potential to influence the flowering phenology of plants. Protracted flowering periods within urban landscapes may result in increased food resources, in the form of nectar, and this high resource availability may support a high density of nectarivorous birds within cities. In order to determine whether there was a difference in the productivity and flowering period associated with urbanisation, we compared the number of flowers produced and duration of flowering period for three species of native tree that were present in streetscapes, remnant vegetation and continuous forest. We also recorded the presence of nectarivorous parrots at flowering trees to determine if the presence of nectarivores was associated with flower productivity. All three species in streetscapes produced more flowers and flowered for longer than in remnants and continuous forest. The number of flowers per tree significantly predicted the presence of nectarivorous parrots in streetscapes. This study demonstrates that the flowering phenology of plants within streetscapes can differ from continuous forest, with remnants appearing to be intermediate. This increased flower productivity within urban landscapes may be partially responsible for the high abundance of nectarivorous parrots within some cities.

Spatial overlap in a solitary carnivore: support for the land tenure, kinship or resource dispersion hypotheses?

There are several alternative hypotheses about the effects of territoriality, kinship and prey availability on individual carnivore distributions within populations. The first is the land-tenure hypothesis, which predicts that carnivores regulate their density through territoriality and temporal avoidance. The second is the kinship hypothesis, which predicts related individuals will be clumped within populations, and the third is the resource dispersion hypothesis, which suggests that resource richness may explain variable sociality, spatial overlap or temporary aggregations of conspecifics. Research on the socio-spatial organization of animals is essential in understanding territoriality, intra- and interspecific competition, and contact rates that influence diverse ecology, including disease transmission between conspecifics and courtship behaviours. We explored these hypotheses with data collected on a solitary carnivore, the cougar (Puma concolor), from 2005 to 2012 in the Southern Yellowstone Ecosystem, Wyoming, USA. We employed 27 annual home ranges for 13 cougars to test whether home range overlap was better explained by land tenure, kinship, resource dispersion or some combination of the three. We found support for both the land tenure and resource dispersion hypotheses, but not for kinship. Cougar sex was the primary driver explaining variation in home range overlap. Males overlapped significantly with females, whereas the remaining dyads (F-F, M-M) overlapped significantly less. In support for the resource dispersion hypothesis, hunting opportunity (the probability of a cougar killing prey in a given location) was often higher in overlapping than in non-overlapping portions of cougar home ranges. In particular, winter hunt opportunity rather than summer hunt opportunity was higher in overlapping portions of female-female and male-female home ranges. Our results may indicate that solitary carnivores are more tolerant of sharing key resources with unrelated conspecifics than previously believed, or at least during periods of high resource availability. Further, our results suggest that the resource dispersion hypothesis, which is typically applied to social species, is applicable in describing the spatial organization of solitary carnivores.

Impacts of a non-native gastropod with a limited distribution; less conspicuous invaders matter too

Most studies focus on fast-spreading invasive species with high impacts, whilst invasive species with restricted distributions tend to be neglected in the ecological literature. The New Zealand gastropod, Zeacumantus subcarinatus, introduced into the Sydney region during the 1920�1930s, typically occurs in rock pools in the mid- to high intertidal. Surveys conducted in 2004 indicated Z. subcarinatus had a restricted distribution, but little is known about whether it is spreading, the environmental conditions that may promote or inhibit its spread, or its interactions with native species. Surveys conducted in 2012 and 2015 showed Z. subcarinatus maintained a similar distribution to that described in 2004. However, rock pools at sites where Z. subcarinatus was present or absent differed in key characteristics. Rock pools at sites lacking Z. subcarinatus had higher cover of macroalgae, reduced cover of bare substratum and higher densities of native gastropods. At invaded sites, there was a significant negative relationship between Z. subcarina- tus and native gastropod densities. Experimental manipulation of Z. subcarinatus confirmed negative effects on the colonization of rock pools by the native gastropod Bembicium nanum, possibly via competition for resources. Impacts on B. nanum were discernable at low and high densities of Z. subcarinatus. By contrast, Z. subcarinatus responded positively to density manipu- lations of B. nanum — possibly higher densities of B. nanum indicate higher resource availability. We have shown that invasive species that have restricted distributions can have significant effects on native fauna and that they potentially deserve more research and management consideration than they currently receive.

Differential larval responses of two ecologically similar insects (Odonata) to temperature and resource variation.

How species respond to shifting environmental conditions is a central question in ecology, especially because ecosystems are experiencing rapidly changing climatic conditions. However, predicting the responses of species interactions and community composition to changing conditions is often difficult. We examined the effects of rearing temperature and resource level on larval survival of two ecologically similar dragonflies, Erythemis collocata and Pachydiplax longipennis. Within high and low (26 and 21°C) temperatures, we crossed species and resource level and reared larvae individually. We predicted that warmer temperatures would reduce survival and increase growth rate, that higher resource availability would increase survival and growth rate, and that the two species would respond similarly. We found that increased temperature reduced survival for both species. There was also an interaction between temperature and species: E. collocata had higher survival at the lower temperature, but lower survival at the higher temperature when compared to P. longipennis. Resource level did not affect survival. In general, P. longipennis grew more than E. collocata, with no effects of temperature or resource level. These results suggest that these species respond dissimilarly to changing thermal conditions, that increased food availability cannot always compensate for the negative effects of higher temperatures, and that climate change may affect interactions between these two sympatric, ecologically similar species, with potential consequences for community composition.

Contrasting growth pattern and nitrogen economy in ancient and modern wheat varieties

Pourazari, F., Vico, G., Ehsanzadeh, P. and Weih, M. 2015. Contrasting growth pattern and nitrogen economy in ancient and modern wheat varieties. Can. J. Plant Sci. 95: 851–860. Nutrient availability, especially nitrogen (N) availability, is a limiting factor for crop production in many regions of the world. Modern crop varieties often produce high yields under high resource availability, whereas ancient varieties are expected to have characteristics more suitable under low resource availability. To test this expectation, we compared the growth and N use efficiency (NUE) of some varieties of ancient hulled wheat, Triticum turgidum spp. dicoccum, and modern free-threshing wheat, T. aestivum and T. turgidum spp. durum. The wheats were grown under different nutrient fertilization (F) levels in two contrasting environments (field in Iran and outdoor growth container in Sweden). Grain yield was significantly higher in modern varieties than in ancient varieties, regardless of fertilization level. In contrast, N uptake efficiency (i.e., mean N in the plant during the main growth period over N in the initial seed grain) and grain N concentration were generally higher in the ancient varieties. Nitrogen use efficiency, defined as the ratio of the grain N content to the sown seed N content, was higher in the ancient varieties only at lower nutrient supply, because in modern varieties higher nutrient supply resulted in a marked increase in NUE through greatly enhanced grain-specific N efficiency (grain yield per mean plant N content during the main growth period). The modern varieties also showed greater fertilization responses in above-ground biomass and leaf area than ancient varieties. The results are relevant in the context of wheat breeding for nutrient use efficiency.

The empty temporal niche: breeding phenology differs between coexisting native and invasive birds

Invasive species face new environmental conditions in their areas of introduction. A correct timing of reproduction is crucial for the successful adjustment of individuals to their environments, yet the temporal aspects of the niche are a neglected subject in the study of biological invasions. When introduced, exotic species could successfully invade new habitats by making use of ecological opportunities, e.g. empty temporal Eltonian niches. Specifically, they may achieve this via conservatism of their native reproductive phenology and/or via plasticity in their reproductive timing. Here we compare the reproductive phenology of a marshland passerine community composed of five successfully established tropical exotic species and twelve coexisting Mediterranean native species along four consecutive years. Both groups showed large differences in their phenology, with exotics reproducing along more months and later in the year than natives. One exotic species even breeds only in late summer and early autumn, when virtually all natives have ceased breeding and when overall bird abundance as well as primary production in cultivated areas (rice fields) were highest. Nonetheless, estimates of population sizes and juvenile survival rates in the study area suggest that late breeding is not maladaptive but instead highly successful. The striking difference in reproductive timing suggests that the exotics may be taking advantage of a vacant Eltonian temporal niche, possibly generated by high resource availability in human-transformed habitats (rice fields and other croplands) in the study area. This study highlights the need to also consider the temporal aspects of the niche when studying invasions.

Predation on heterospecific larvae by adult females of Kampimodromus aberrans, Amblyseius andersoni, Typhlodromus pyri and Phytoseius finitimus (Acari: Phytoseiidae).

The predatory mites Kampimodromus aberrans (Oudemans), Amblyseius andersoni (Chant), Typhlodromus pyri Scheuten and Phytoseius finitimus Ribaga are important biological control agents in orchards and vineyards in Europe and elsewhere. They can coexist in the same habitat and engage in intraguild predation (IGP). In the laboratory we evaluated the longevity, fecundity and prey consumption of females of these predatory mites fed with heterospecific larvae considered as intraguild prey (IG-prey). The survival and age-specific oviposition curves of predatory mites fed with pollen were compared with those obtained on different IG-prey. We assessed the prey conversion rate into eggs expressed by the different IG-predator as an indicator of their capacity to persist when prey is diminishing. Results suggest that A. andersoni should be considered the superior intraguild predator but the least efficient in food conversion. Phytoseius finitimus appeared to suffer from intraguild predation, and its efficiency in food conversion was not superior to that of K. aberrans and T. pyri. The profiles of K. aberrans and T. pyri were less definite. The comparison between pollen and IG-prey diets confirmed the positive effect of pollen on the fecundity of all four predatory mite species. Fecundity was higher on pollen than on IG-prey. We can suggest that A. andersoni have the potential to exclude the other predatory mites only at high food resource availability, whereas low levels of food availability can favor the other species in IGP.

Effects of Carbon Structures of Supported Pt Catalysts on the Performance of Polymer Electrolyte Fuel Cells

At present, the cathode catalysts of PEFCs require an appreciable amount of costly platinum or its alloys, due to the slow kinetics of the oxygen reduction reaction (ORR) in an acidic environment at low operating temperatures [1]. Because of the high cost and limited availability of Pt resources for the large-scale commercialization, it is very important to reduce the amount of Pt by developing highly efficient cathode catalyst layers (CLs). In the previous works [2-3], we demonstrated the impotance of two factors for the design of high performance cathode CLs. The first is the higher location of Pt particles supported on the exterior surface of carbon supports; the interior/exterior location was estimated from the comparison of transmission electron microscopic (TEM) images and secondary electron microscopic (SEM) images while applying a rotatable specimen holder. The second is the optimized distribution of ionomer on the surfaces both of Pt particles and carbon particles, which was characterized by cold field emission-scanning transmission electron microscopic (STEM) images. Based on the above background, in this study, we investigate the effects of the pore structures of Pt supports, locations of Pt particles and ionomer (Aquivion™ D70-20BS, IEC 1.43 ± 0.04 meq g-1, Solvay-Solexis) on the cell performances of various carbon-supported Pt catalysts, by using TEM (HT7700S, Hitachi High-Technologies) and electrochemical characterization. Two types of commercial 30 wt% Pt-loaded catalysts (c-Pt/CB, TEC10E30E and c-Pt/GCB, TEC10EA30E,Tanaka Kikinzoku Kogyo K. K.) and 30 wt% acetylene black (AB)-supported Pt catalysts, prepared in house by the nanocapsule method [4] (n-Pt/AB800 and n-Pt/AB250, specific surface area of AB800 and AB250: 800 m2 g-1 and 250 m2 g-1, Denki Kagaku Kogyo K. K.), were used as the cathode catalysts.The effective Pt surface area (S(e)Pt) that can practically contribute to the ORR was directly calculated by the Pt size distribution from the comparison of TEM images and SEM images with the application of the rotatable specimen holder [2]. The S(e)Pt was increased by using AB supports and our nanocapsule method: 87 m2 gPt -1 for AB800 and 107 m2 gPt -1 for AB250, all being higher than that of the CB support (32 m2 gPt -1). This was in good agreement with the order of their cell performance in the high current density regions. In addition, the ionomers of n-Pt/AB800 and n-Pt/AB250 covered more uniformly and continuously over the surfaces both of the Pt particles and carbon particles, than those of the c-Pt/GCB catalyst, for which the Pt particles were predominantly observed on the exterior surface (S(e)Pt = 68 m2 gPt -1). Such improvement of the effective Pt surface area and ionomer distribution led to a much higher cell performance of the AB-supported Pt catalysts under high current densities. In particular, the n-Pt/AB250 catalyst, for which all of the Pt particles existed only on the exterior surface (see Figure 1), might establish the best-balanced supply path of protons and oxygen in the high current density regions, in which the reactant feed is rate-limiting. Figure 2 (a) shows the mass power as a function of relative humidity (RH) for the carbon-supported Pt catalysts. The n-Pt/AB800 and n-Pt/AB250 catalysts were able to achieve high performance over a wide range of RH (53-100%): 12.6-15.1 W mgPt -1 for the n-Pt/AB800 and 13.2-15.4 W mgPt -1for the n-Pt/AB250. In contrast, the c-Pt/CB catalyst exhibited a lower cell performance, which might be attributed to the lower effective Pt surface area; the Pt particles in the interior make it difficult to access oxygen and protons sufficiently, thereby leading to larger concentration losses due to the limited supply of oxygen and protons in the high current density regions, as illustrated in Figure 2 (b) and (c). These results indicate that the n-Pt/AB250 catalyst is most useful in order to achieve the high current densities required by actual operating conditions, such as those in automotive applications. Acknowledgment This work was supported by funds for the “Research on Nanotechnology for High Performance Fuel Cells” (HiPer-FC)project from the New Energy and Industrial Technology Development Organization (NEDO) of Japan. The authors are grateful to Denki Kagaku Kogyo K. K. for kindly providing the experimental AB supports.

Enhanced-Adaptive Pattern Attack Recognition Technique (E-APART) Against EDoS Attacks in Cloud Computing

Cloud Computing is most widely used in current technology. It provides a higher availability of resources to greater number of end users. In the cloud era, security has develop a reformed source of worries. Distributed Denial of Service (DDoS) and Economical Denial of Sustainability (EDoS) are attacks that can affect the ‘pay-per-use' model. This model automatically scales the resources according to the demand of consumers. The functionality of this model is to mitigate the EDoS attack by some tactical attacker/s, group of attackers or zombie machine network (BOTNET) to minimize the availability of the target resources, which directly or indirectly reduces the profits and increase the cost for the cloud operators. This paper presents a model called Enhanced-APART which is step further of the authors' previous model (APART) that can be used to mitigate the EDoS attack from the cloud platform and shows the nature of the attack. Enhanced-APART model offers pre-shared security mechanism to ensure the access of legitimate users on the cloud services. It also performs pattern analysis in order to detect the EDoS caused by BOTNET mechanism and includes time-based and key-sharing post-setup authentication scheme to prevent the replication or replay attacks and thus results in mitigation of EDoS attack.

TIC y mediaciones culturales en la educación superior: hacia un programa multidimensional

<p>Tras una primera etapa de reflxión sobre la relación TIC-educación centrada en la brecha digital, se viene reconociendo la necesidad de estudiar, además, la cuestión de la capacitación necesaria para sacar provecho a los recursos tecnológicos disponibles. Sin embargo, se sigue prestando poca atención a la dimensión simbólica de la tecnología en general y de las TIC en particular, lo que genera serias dudas acerca del papel real que juega la cultura tanto en el discurso de la cultura digital como en el debate sobre la educación en la sociedad del conocimiento. En este sentido, el paso de la cultura como categoría residual a variable independiente surge de reconocer que: (a) las personas no sólo usan las tecnologías, sino que, sobre todo, las personalizan, las dotan de sentido y las hacen parte integral de su experiencia de mundo, y que (b) dichos procesos emergen no solo de experiencias subjetivas con las TIC, sino de robustas narrativas culturales en torno a las tecnologías. Este giro epistemológico hace posible un análisis multidimensional de las TIC en la educación, en el que la convergencia entre las dimensiones funcional y<br />sociocultural de la tecnología arrojaría luces sobre la contradicción que muchos críticos de las nuevas tecnologías han puesto de manifisto: la alta disponibilidad de recursos tecnológicos no garantiza mejores resultados en el plano cognitivo ni un enriquecimiento de nuestro capital cultural como sociedad. De ahí que la introducción de un programa cultural, ambicioso y dinámico, sea decisivo en el futuro de la investigación sobre educación superior y TIC.</p>

Decoding size distribution patterns in marine and transitional water phytoplankton: from community to species level.

Understanding the mechanisms of phytoplankton community assembly is a fundamental issue of aquatic ecology. Here, we use field data from transitional (e.g. coastal lagoons) and coastal water environments to decode patterns of phytoplankton size distribution into organization and adaptive mechanisms. Transitional waters are characterized by higher resource availability and shallower well-mixed water column than coastal marine environments. Differences in physico-chemical regime between the two environments have been hypothesized to exert contrasting selective pressures on phytoplankton cell morphology (size and shape). We tested the hypothesis focusing on resource availability (nutrients and light) and mixed layer depth as ecological axes that define ecological niches of phytoplankton. We report fundamental differences in size distributions of marine and freshwater diatoms, with transitional water phytoplankton significantly smaller and with higher surface to volume ratio than marine species. Here, we hypothesize that mixing condition affecting size-dependent sinking may drive phytoplankton size and shape distributions. The interplay between shallow mixed layer depth and frequent and complete mixing of transitional waters may likely increase the competitive advantage of small phytoplankton limiting large cell fitness. The nutrient regime appears to explain the size distribution within both marine and transitional water environments, while it seem does not explain the pattern observed across the two environments. In addition, difference in light availability across the two environments appear do not explain the occurrence of asymmetric size distribution at each hierarchical level. We hypothesize that such competitive equilibria and adaptive strategies in resource exploitation may drive by organism’s behavior which exploring patch resources in transitional and marine phytoplankton communities.