Is space management of female meadow voles (Microtus pennsylvanicus) related to nutritive quality of plants?

Summary It is thought by many (see Ims 1987 for review; Desy and Batzli 1989) that high quality food regulate population processes, territoriality and mating systems among small herbivores like meadow voles (Microtus pennsylvanicus). We thought that comparisons of nutritive components from selected plants eaten by sexually active and inactive voles, as well as between territorial and non territorial sexually active females would bring some light into these theoretical considerations. Sexually active females did have a higher diet quality over inactive ones and over active and inactive males. Nutritive components of selected species from territorial reproductive females did not vary significantly from those of the non territorial females the year of higher crowding conditions but they varied significantly the following year when population density of voles was much lower. This decline in food quality coincided with a switch in food selection. Since there were only eight plant species involved in such processes, we think that crowding condition and availability of high quality food are two factors involved concurrently in space management and territoriality among voles.     

Identification of tannin–degrading microorganisms in the gut of plateau pikas (Ochotona curzoniae) and root voles (Microtus oeconomus)

Gut microorganisms are thought to play a role in the degradation of plant secondary metabolites in herbivores. Here, we examined the presence of tannin–degrading microorganisms in the gut of two herbivores, plateau pikas (Ochotona curzoniae) and root voles (Microtus oeconomus). Tannase activity in the feces of wild plateau pikas and root voles increased from June to August, corresponding to the increase in condensed and hydrolyzable tannin concentrations in plants during this period. Using intragastric tannic acid infusion, we found that tannase activities were significantly higher following administration of three concentrations of tannic acid than that in the control group for root voles. In contrast, for plateau pikas, animals administered tannic acid exhibited lower tannase activity in low–dose and high–dose groups than that in the control group. Tannase activities in root voles were higher than those in plateau pikas among different months and in different tannic acid infusion groups. Three tannin–degrading anaerobic strains were isolated from the cecum of plateau pikas (termed A1, A2, and A3) and root voles (termed M1, M2, and M3). 16 s rDNA sequencing assigned isolates A1 and M1 to the genus Enterobacter, A2 and M2 to the genus Shigella, and A3 and M3 to the genus Staphylococcus. These data provided the first evidence of microorganisms with tannin–degrading activity in the gut of plateau pikas and root voles. We speculated that both animals could degrade tannins in the gut, but that root voles would have a greater ability to process tannins than plateau pikas.     

Defining “American” in the context of immigration: a case study of Helping Hands Elementary

Immigration has dramatically changed the face of the nation in the last thirty years, yet it is unclear how children currently define “Americanness” in light of these demographic and cultural shifts. This research explores how elementary students define what it means to be American in the context of immigration-driven diversity. Based on a survey of fourth and fifth graders in an elementary school located in a high-immigrant community, the author shows that despite the diversity of the school and local surroundings, and the multicultural ideology espoused by school staff, students predominately defined “American” in ethnocultural terms – specifically, as white, US-born, and English-speaking. At the same time, a small group of students challenged this narrative and defined Americans in pluralist terms. This study suggests that schools aiming to create inclusive learning communities in an increasingly diverse nation may need more direct approaches to teaching a culturally pluralist model of America.     

Templates of food–habitat resources for the organization of soil animals in temperate and tropical forests

The functioning and structure of terrestrial ecosystems are shaped and maintained by plant–decomposer interactions. The food and habitat of animal populations are biogenic and are mainly of plant origin (plant litter) in terrestrial ecosystems. Primary resources of the food-habitat template for the organization of soil animals are provided by the primary production of plants, and are then modified through decomposition processes by microbial populations. In the microbial decomposition system, the efficiency of carbon utilization by microbial decomposers characterizes the decomposition processes between tropical and temperate forest ecosystems. Tropical forests show poor development of soil reservoir systems because of the high efficiency of lignin decomposition by microbial populations. The decomposition processes of leaf litter are described briefly for the understanding of organization of soil animal communities in tropical and temperate forests. A comparison of decomposition processes shows qualitative differences in decomposition between temperate and tropical forests. The composition of functional groups of soil animals is well explained by the decomposition processes in both forests.     

Predators,fire or resources: What drives the distribution of herbivores in fragmented mesic forests?

Trophic interactions and disturbance events can shape the structure and function of ecosystems. However, the effects of drivers such as predation, fire and climatic variables on species distributions are rarely considered concurrently. We used a replicated landscape‐scale predator management experiment to compare the effects of red fox Vulpes vulpes control, time‐since‐fire, vegetation type and other environmental variables on native herbivore distributions. Occurrence data for four native herbivores and an invasive predator – the red fox – were collected from 240 sites across three baited (for lethal fox control) and three unbaited forest blocks (4659–9750 ha) in south‐western Victoria, Australia, and used to build species distribution models. The herbivore taxa were as follows: red‐necked wallaby Macropus rufogriseus, black wallaby Wallabia bicolour, grey kangaroo Macropus fuligenosus and Macropus giganteus and common brushtail possum Trichosurus vulpecula. Fox control and fire had little effect on herbivore occurrence, despite the literature suggesting it can influence abundance, while climate, proximity to farmland and topography were more influential. This may be because the region’s high productivity and agricultural pastures subsidise food resources for both predators and prey within the forest blocks and so dampen trophic interactions. Alternatively, these drivers may affect herbivore abundance, but not herbivore occurrence. Understanding the drivers of herbivore distributions is an important step in predicting the effects of herbivory on other species, particularly after management interventions such as predator control and prescribed burns.     

Pre-implantation Pregnancy Disruption in Female Meadow Voles Microtus pennsylvanicus (Rodentia: Muridae): Male Competition or Female Mate Choice?

I investigated alternative hypotheses concerning the functions of pre-implantation male-induced pregnancy disruption in meadow voles. Disruptions may be viewed as: 1. Postcopulatory male competition; 2. A mechanism for postcopulatory mate choice by females; and 3. A means of benefitting females by terminating investment in litters that may be harmed by new males. Female voles were paired with a second male 3 d after mating with their first mate. Behavioural interactions between the female and each male were compared for females that disrupted or retained the pregnancy sired by the first male. Whether they were the females' first or second mates, males siring litters showed similar high levels of approach and moderately high aggression, behaviour that differed from the females' other mates. Disrupted females huddled sooner with their second mates than females that retained their original pregnancies, and females tended to approach males that approached them. These results suggest that females influence whether a disruption occurs by the amount of contact they initiate with the second male, and thus pregnancy disruption may facilitate postcopulatory mate choice by females. This pre-implantation disruption did not enhance female reproductive success: pup survival was the same whether or not a disruption occurred, and males living with pups they had sired (after a disruption) spent as much time with them as males with unrelated pups (females did not disrupt).     

Perception of facial attractiveness requires some attentional resources: implications for the “automaticity” of psychological adaptations

Traditional criteria for modularity assert that perceptual adaptations for processing evolutionarily important stimuli should operate “automatically” in the sense of requiring no central attentional resources. Here, we test the validity of this automaticity criterion by assessing the attentional demands of a well-studied perceptual adaptation: judgment of facial attractiveness. We used locus-of-slack logic in a dual-task psychological refractory period paradigm, where Task 1 was a speeded judgment of tone pitch (low vs. high), and Task 2 was a speeded judgment of whether a face was attractive or unattractive, with the Task-2 judgment manipulated to have a low or a high difficulty level. In two studies (N=36 and N=73 female participants; 384 trials each), the Task 2 difficulty effects were additive with stimulus-onset asynchronies (100, 300, 500 or 900 ms) on Task 2 response times. According to the locus-of-slack logic, this result implies that participants could not discriminate facial attractiveness level, while their central attentional resources were still occupied by Task 1. If the human capacity for perceiving facial attractiveness—a premier example of an adaptation—does not show automaticity in this sense, automaticity may not be a useful criterion for identifying psychological adaptations.     

Elevated volatile concentrations in high‐nutrient plants: do insect herbivores pay a high price for good food?

1. A tritrophic perspective is fundamental for understanding the drivers of insect–plant interactions. While host plant traits can directly affect insect herbivore performance by either inhibiting or altering the nutritional benefits of consumption, they can also have an indirect effect on herbivores by influencing rates of predation or parasitism. 2. Enhancing soil nutrients available to trees of the genus Eucalyptus consistently modifies plant traits, typically improving the nutritional quality of the foliage for insect herbivores. We hypothesised that resulting increases in volatile essential oils could have an indirect negative effect on eucalypt‐feeding herbivores by providing their natural enemies with stronger host/prey location cues. 3. Eucalyptus tereticornis Smith seedlings were grown under low‐ and high‐nutrient conditions and the consequences for the release of volatile cues from damaged plants were examined. The influence of 1,8‐cineole (the major volatile terpene in many Eucalyptus species) on rates of predation on model caterpillars in the field was then examined. 4. It was found that the emission of cineole increased significantly after damage (artificial or herbivore), but continued only when damage was sustained by herbivore feeding. Importantly, more cineole was emitted from high‐ than low‐nutrient seedlings given an equivalent amount of damage. In the field, predation was significantly greater on model caterpillars baited with cineole than on unbaited models. 5. These findings are consistent with the hypothesis that any performance benefits insect herbivores derive from feeding on high‐nutrient eucalypt foliage could be at least partially offset by an increased risk of predation or parasitism via increased emission of attractive volatiles.     

Reproductive traits of marine terns (Sternidae): evidence for food limitation in the tropics?

Marine terns breed between 80°N and 70°S, making them a suitable group for examining links between latitude and reproductive traits. We investigated such traits for 34 taxa in seven genera, using analyses of residuals to correct for effects of e.g. female body mass and egg mass on other life history traits. Both tree- and K-means clustering, based on four traits excluding chick provisioning mode, identified two groups of terns—those that breed on tropical oceanic islands and those that breed along mainland coasts and at temperate islands (>40° from the Equator). Among mainland terns, there is a tendency for reduced clutch investment at low latitudes both between and within species. There is no interspecific latitudinal variation in incubation or fledging period of these terns, but intraspecific variation in fledging period (longer in the tropics) has been reported for one species. Tropical island terns, which mostly breed at sites lacking native ground predators, show extreme clutch reduction and lay a single, relatively large egg that has a long incubation period. Fledging periods are also long, despite the fact that these are the only terns to use multiple prey loading or regurgitation to feed their chicks. These patterns are interpreted as responses to low food availability stemming from a combination of low oceanic productivity, high bird densities because of breeding space limitation and localised prey depletion associated with central place foraging.     

Does climate affect host-plant quality? Annual variation in the quality of balsam fir as food for spruce budworm

Summary The hypothesis that annual climatic variation can affect the nutritive value of host-plant tissue for a herbivore was tested. Larvae of a single generation of western spruce budworm, Choristoneura occidentalis Free., were fed foliages that had been collected on five consecutive springs from a stand of balsam fir Abies balsamea (L.) Mill. Budworm of both sexes were about 20 percent heavier at pupation when fed folages that had been produced in early rather than later spring seasons. This could result in an estimated 25 percent difference in the reproductive rate of females. It is concluded that annual variations in spring climate can affect the nutritive value of forage.     

Consistency of quality attributes for the glycosylated monoclonal antibody Humira® (adalimumab)

Humira® (adalimumab) is a recombinant human IgG1 monoclonal antibody (mAb) glycoprotein consisting of 1330 amino acids that is specific for human tumor necrosis factor (TNF). The biological activity and clinical profile of mAb therapeutics, including adalimumab, is influenced by their protein structure and glycosylation patterns, which can be affected by the expression system, cell culture conditions and purification process methodology. While clinical outcome cannot yet be attributed to many of the individual structural features that constitute a mAb, it is evident that detailed structural attribute analysis is necessary if structural contributions to function are to be comprehensively defined. Adalimumab product quality data generated from over a decade of manufacturing across multiple production sites and through a series of manufacturing scale changes are presented here. These data reveal a consistent and tightly controlled profile for the product.     

Karyological and allozyme variability of Far Eastern voles Microtus fortis Büchner, 1889 (Cricetidae, Rodentia) from the Russian Far East

Karyological (G-, C-, and NOR-banding) and allozyme analyses were carried out for island and continental populations of the vole Microtus fortis from the Far East of Russia. Variability of the autosome pair 7 was found. The presence of variation in the number of telomere heterochromatin blocks in the populations of Far Eastern voles was confirmed. NOR-staining of the Far Eastern vole chromosomes was carried out, showin stability of the number and the positions of the nucleolus organizer regions. Ten enzyme systems and three nonenzyme proteins (controlled in total by 25 interpretable loci) were examined in the Far Eastern vole from the island and continental populations. All of the loci were shown to be monomorphic, except for one esterase locus, which exhibited polymorphism at the intrapopulation and interpopulation levels. The issue of distribution of the Far Eastern vole subspecies is discussed. It is suggested that M. fortis pelliceus occurs not only in the Russian Far East, but also in Northern Transbaikalia.     

Karyological and allozyme variability of far eastern voles Microtus fortis Büchner, 1889 (Cricetidae, Rodentia) from the Russian Far East

Karyological (G-, C-, and NOR-banding) and allozyme analyses were carried out for island and continental populations of the vole Microtus fortis from the Far East of Russia. Variability of the autosome pair 7 was found. The presence of variation in the number of telomere heterochromatin blocks in the populations of Far Eastern voles was confirmed. NOR-staining of the Far Eastern vole chromosomes was carried out, showing stability of the number and the positions of the nucleolus organizer regions. Ten enzyme systems and three non-enzyme proteins (controlled in total by 25 interpretable loci) were examined in the Far Eastern vole from the island and continental populations. All of the loci were shown to be monomorphic, except for one esterase locus, which exhibited polymorphism at the intrapopulation and interpopulation levels. The issue of distribution of the Far Eastern vole subspecies is discussed. It is suggested that M. fortis pelliceus occurs not only in the Russian Far East, but also in Northern Transbaikalia.     

Fitting the bill: do different winter food resources influence juniper titmouse (Baeolophus ridgwayi) bill morphology?

Divergent adaptive selection is a prominent mechanism influencing patterns of morphological diversity. We used the juniper titmouse [Baeolophus ridgwayi (Richmond, 1902)], a nonmigratory passerine that inhabits woodlands throughout western North America, to investigate variation in bill morphology in relation to diet and geography. We gathered data from museum specimens and used morphometric techniques to determine the relative strength of support for competing hypotheses using information theoretics: (1) differences in bill morphology are predicted by a key winter food resource that each regional population consumes (seeds of different juniper tree species); or (2) bill morphology scales with body size, and both increase along a latitudinal gradient. Juniper species emerged as the variable with the most support explaining variation in bill size, supporting the hypothesis that seed sizes influence bill size, independently of body size. The shape analysis revealed no distinct patterns in bill shape variation, but employed a powerful method for evaluating the strength of support for numerous candidate models. The differences in bill size of juniper titmice across their range are likely to reflect adaptive variation, because bill morphology is highly heritable in birds, juniper titmouse gene flow appears to be relatively low, and there is a clear mechanistic explanation for why bill sizes may differ among the ranges of the three juniper species. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 667–679.     

LC–MS based global metabolite profiling: the necessity of high data quality

LC–MS based global metabolite profiling currently lacks detailed guidelines to demonstrate that the obtained data is of high enough analytical quality. Insufficient data quality may result in the failure to generate a hypothesis, or in the worst case, a false or skewed hypothesis. After assessing the literature, it is apparent that an analytically focused summary and critical discussion related to this subject would be beneficial for both beginners and experts engaged in this field. A particular focus will be placed on data quality, which we here define as the degree to which a set of parameters fulfills predetermined criteria, similar to the established guidelines for targeted analysis. However, several of these parameters are difficult to assess since holistic approaches measure thousands of metabolites in parallel and seldom include predefined knowledge of which metabolites will differ between sample groups. In this review, the following parameters will be discussed in detail: reproducibility, selectivity, certainty of metabolite identification and metabolite coverage. The review systematically describes the generic workflow for LC–MS based global metabolite profiling and highlights how each separate part may affect data quality. The last part of the review describes how data quality can be evaluated as well as identifies areas where additional improvement is needed. In this review, we provide our own analytical opinions in regards to evaluation and, to some extent, improvement of data quality.     

Etiology of Turkey “X” disease in retrospect: A case for the involvement of cyclopiazonic acid

The etiology of the classical turkey “X” disease syndrome is reappraised based on original reports in conjunction with current information. The clinical signs described in those original reports cannot be totally explained as being typical for aflatoxicosis. The unexplained effects of the disease can be resolved by the proposed presence of the mycotoxin cyclopiazonic acid which is frequently produced byAspergillus flavus along with the aflatoxins.     

Mating frequency as an indication of food quality for the bulb mite,Rhizoglyphus robini Claparède

Mating frequency of the bulb mite, Rhizoglyphus robini Claparède (Astigmata: Acaridae) was recorded for 23 days on 6 concentrations of peanut extract. The largest numbers of couplings and of adults were obtained on the undiluted (100%) extract, and the fewest on the most diluted (10%) diet. Good association between mating frequency and adult numbers was also observed on several other foods.