Selenium Digestibility and Bioactivity in Dogs: What the Can Can,the Kibble Can’t

There is a growing concern for the long-term health effects of selenium (Se) over- or underfeeding. The efficiency of utilization of dietary Se is subject to many factors. Our study in dogs evaluated the effect of diet type (canned versus kibble) and dietary protein concentration on Se digestibility and bioactivity. Canned and kibble diets are commonly used formats of dog food, widely ranging in protein concentration. Twenty-four Labrador retrievers were used and four canned and four kibble diets were selected with crude protein concentrations ranging from 10.1 to 27.5 g/MJ. Crude protein concentration had no influence on the digestibility of Se in either canned or kibble diets, but a lower Se digestibility was observed in canned compared to kibble diets. However, the biological activity of Se, as measured by whole blood glutathione peroxidase, was higher in dogs fed the canned diets than in dogs fed the kibble diets and decreased with increasing crude protein intake. These results indicate that selenium recommendations in dog foods need to take diet type into account.     

Can 1000 reviews be wrong? Actin, alpha-Catenin, and adherens junctions

Coupling between cell adhesion and the actin cytoskeleton is thought to require a stable link between the cadherin-catenin complex and actin that is mediated by alpha-catenin. In this issue of Cell, the Weis and Nelson groups call this static model into question, showing that alpha-catenin can directly regulate actin dynamics (Drees et al., 2005 and Yamada et al., 2005).     

Can the red mangrove provide food,feed and fertilizer?

The red mangrove is one of the principal features of the coastal vegetation throughout tropical America, Mexico, the West Indies, the Bahamas, Bermuda and southern Florida. It is of primary importance as a land retainer and builder. Secondarily, its bark is a source of tannin and yields resins suitable for plywood adhesive. Mangrove wood is heavy and durable. The bark, leaves and shoots furnish various dyes and the bark is an excellent fuel and is much used locally for medicinal purposes. In southern Florida there has been active interest in the value of mangrove leaf meal as cattle feed, the dried and ground leaves have been sold as “Maritime Tea” and prepared in tablet form as a dietary supplement. The leaf meal and the sawdust have been tested as soil conditioners. Despite their high tannin content, red mangrove leaves may warrant investigation as an abundant source of protein.     

Man, Energy, and Anthropology: I Can Feel the Heat, But Where's the Light?

Anthropology should deal with man holistically, but has failed to do so. The field is unfortunately split between mentalistic and materialistic schools and has not developed a theory to cope with the complexity of large contemporary societies. Energy similarly has been little studied by anthropology because there has been no theory sufficient for the purpose. The thermodynamics of structures far from equilibrium and the dissipative structure model of Ilya Prigogine offer a method for both studying energy in society and dealing with society as a whole. Anthropologists are urged to pursue study of this area because it is critical for an understanding of human destiny . [energy, holism, materialism-mentalism, dissipative structures, complex societies]     

Why Can’t Rodents Vomit? A Comparative Behavioral,Anatomical, and Physiological Study

The vomiting (emetic) reflex is documented in numerous mammalian species, including primates and carnivores, yet laboratory rats and mice appear to lack this response. It is unclear whether these rodents do not vomit because of anatomical constraints (e.g., a relatively long abdominal esophagus) or lack of key neural circuits. Moreover, it is unknown whether laboratory rodents are representative of Rodentia with regards to this reflex. Here we conducted behavioral testing of members of all three major groups of Rodentia; mouse-related (rat, mouse, vole, beaver), Ctenohystrica (guinea pig, nutria), and squirrel-related (mountain beaver) species. Prototypical emetic agents, apomorphine (sc), veratrine (sc), and copper sulfate (ig), failed to produce either retching or vomiting in these species (although other behavioral effects, e.g., locomotion, were noted). These rodents also had anatomical constraints, which could limit the efficiency of vomiting should it be attempted, including reduced muscularity of the diaphragm and stomach geometry that is not well structured for moving contents towards the esophagus compared to species that can vomit (cat, ferret, and musk shrew). Lastly, an in situ brainstem preparation was used to make sensitive measures of mouth, esophagus, and shoulder muscular movements, and phrenic nerve activity–key features of emetic episodes. Laboratory mice and rats failed to display any of the common coordinated actions of these indices after typical emetic stimulation (resiniferatoxin and vagal afferent stimulation) compared to musk shrews. Overall the results suggest that the inability to vomit is a general property of Rodentia and that an absent brainstem neurological component is the most likely cause. The implications of these findings for the utility of rodents as models in the area of emesis research are discussed.     

Can Invasive Species Facilitate Native Species? Evidence of How, When, and Why These Impacts Occur

Although the predatory and competitive impacts of biological invasions are well documented, facilitation of native species by non-indigenous species is frequently overlooked. A search through recent ecological literature found that facilitative interactions between invasive and native species occur in a wide range of habitats, can have cascading effects across trophic levels, can re-structure communities, and can lead to evolutionary changes. These are critical findings that, until now, have been mostly absent from analyses of ecological impacts of biological invasions. Here I present evidence for several mechanisms that exemplify how exotic species can facilitate native species. These mechanisms include habitat modification, trophic subsidy, pollination, competitive release, and predatory release. Habitat modification is the most frequently documented mechanism, reflecting the drastic changes generated by the invasion of functionally novel habitat engineers. Further, I predict that facilitative impacts on native species will be most likely when invasive species provide a limiting resource, increase habitat complexity, functionally replace a native species, or ameliorate predation or competition. Finally, three types of facilitation (novel, substitutive, and indirect) define why exotic species can lead to facilitation of native species. It is evident that understanding biological invasions at the community and ecosystem levels will be more accurate if we integrate facilitative interactions into future ecological research. Since facilitative impacts of biological invasions can occur with native endangered species, and can have wide-ranging impacts, these results also have important implications for management, eradication, and restoration.Contribution Number 2293, Bodega Marine Laboratory, University of California at Davis.     

Religion and Bioethics: Can We Talk?

Religious voices were important in the early days of the contemporary field of bioethics but have now become decidedly less prominent. This is unfortunate because religious elements are essential parts of the most foundational aspects of bioethics. The problem is that there is an incommensurability between religious language and languages of public discourse such as the “public reason” of John Rawls. To eliminate what is unique in religious language is to lose something essential. This paper examines the reasons for the marginalization of religion in bioethics, shows the limitations of Rawls’s notion of public reason, and argues for a more robust role for theology in articulating a new language for public discourse in bioethics.     

Can the growth factors PTHrP,Ihh and VEGF,together regulate the development of a long bone?

Endochondral ossification is the process of differentiation of cartilaginous into osseous tissue. Parathyroid hormone related protein (PTHrP), Indian hedgehog (Ihh) and vascular endothelial growth factor (VEGF), which are synthesized in different zones of the growth plate, were found to have crucial roles in regulating endochondral ossification. The aim of this study was to evaluate whether the three growth factors PTHrP, Ihh and VEGF, together, could regulate longitudinal growth in a normal human, fetal femur. For this purpose, a one-dimensional finite element (FE) model, incorporating growth factor signaling, was developed of the human, distal, femoral growth plate. It included growth factor synthesis in the relevant zones, their transport and degradation and their effects. Simulations ran from initial hypertrophy in the center of the bone until secondary ossification starts at approximately 3.5 months postnatal. For clarity, we emphasize that no mechanical stresses were considered. The FE model showed a stable growth plate in which the bone growth rate was constant and the number of cells per zone oscillated around an equilibrium. Simulations incorporating increased and decreased PTHrP and Ihh synthesis rates resulted, respectively, in more and less cells per zone and in increased and decreased bone growth rates. The FE model correctly reflected the development of a growth plate and the rate of bone growth in the femur. Simulations incorporating increased and decreased PTHrP and Ihh synthesis rates reflected growth plate pathologies and growth plates in PTHrP-/- and Ihh-/- mice. The three growth factors, PTHrP, Ihh and VEGF, could potentially together regulate tissue differentiation.     

Can initial and additional compensatory steps be predicted in young,older, and balance-impaired older females in response to anterior and posterior waist pulls while standing?

The initiation of a single compensatory step in response to balance perturbations has been predicted with accuracies of up to 71%. We sought to determine whether similar methods also could be used to predict the onset of additional compensatory steps in both healthy and balance-impaired older females. Anterior and posterior waist pulls of five different magnitudes were applied to 13 unimpaired young (mean age 23 years), 12 unimpaired older (mean age 71 years), and 15 balance-impaired older (mean age 76 years) women. Body segment kinematic data were recorded at 100 Hz. A step was predicted when the time for the center-of-mass to reach the vertical projection of the boundary of the base-of-support fell below a certain threshold. The results show that 83% of all steps and non-steps were correctly predicted at an optimal time-to-boundary threshold (tau(opt)) of 0.78 s. Step prediction accuracy did not differ significantly by group: 86% of steps and non-steps by young, 84% by unimpaired old, and 82% by balance-impaired old women were correctly predicted at tau(opt) of 0.58, 0.67, and 0.78 s, respectively. Anterior steps and non-steps were predicted more accurately than posterior ones (94% vs. 79% correct at tau(opt) of 0.52 and 0.84 s, respectively) and initial steps were better predicted than additional ones (87% vs. 81% correct at tau(opt) of 0.77 and 0.34 s, respectively). We conclude that this step prediction method reasonably predicts initial and additional steps in the anterior and posterior direction by all three subject cohorts.     

Can Nocturnal Flight Calls of the Migrating Songbird,American Redstart,Encode Sexual Dimorphism and Individual Identity?

Bird species often use flight calls to engage in social behavior, for instance maintain group cohesion and to signal individual identity, kin or social associations, or breeding status of the caller. Additional uses also exist, in particular among migrating songbirds for communication during nocturnal migration. However, our understanding of the information that these vocalizations convey is incomplete, especially in nocturnal scenarios. To examine whether information about signaler traits could be encoded in flight calls we quantified several acoustic characteristics from calls of a nocturnally migrating songbird, the American Redstart. We recorded calls from temporarily captured wild specimens during mist-netting at the Powdermill Avian Research Center in Rector, PA. We measured call similarity among and within individuals, genders, and age groups. Calls from the same individual were significantly more similar to one another than to the calls of other individuals, and calls were significantly more similar among individuals of the same sex than between sexes. Flight calls from hatching-year and after hatching-year individuals were not significantly different. Our results suggest that American Redstart flight calls may carry identifiers of gender and individual identity. To our knowledge, this is the first evidence of individuality or sexual dimorphism in the flight calls of a migratory songbird. Furthermore, our results suggest that flight calls may have more explicit functions beyond simple group contact and cohesion. Nocturnal migration may require coordination among numerous individuals, and the use of flight calls to transmit information among intra- and conspecifics could be advantageous. Applying approaches that account for such individual and gender information may enable more advanced research using acoustic monitoring.     

Can Ingestion of Lead Shot and Poisons Change Population Trends of Three European Birds: Grey Partridge,Common Buzzard,and Red Kite?

Little is known about the magnitude of the effects of lead shot ingestion alone or combined with poisons (e.g., in bait or seeds/granules containing pesticides) on population size, growth, and extinction of non-waterbird avian species that ingest these substances. We used population models to create example scenarios demonstrating how changes in these parameters might affect three susceptible species: grey partridge (Perdix perdix), common buzzard (Buteo buteo), and red kite (Milvus milvus). We added or subtracted estimates of mortality due to lead shot ingestion (4–16% of mortality, depending on species) and poisons (4–46% of mortality) reported in the UK or France to observed mortality of studied populations after models were calibrated to observed population trends. Observed trends were decreasing for partridge (in continental Europe), stable for buzzard (in Germany), and increasing for red kite (in Wales). Although lead shot ingestion and poison at modeled levels did not change the trend direction for the three species, they reduced population size and slowed population growth. Lead shot ingestion at modeled rates reduced population size of partridges by 10%, and when combined with bait and pesticide poisons, by 18%. For buzzards, decrease in mean population size by lead shot and poisons combined was much smaller (≤ 1%). The red kite population has been recovering; however, modeled lead shot ingestion reduced its annual growth rate from 6.5% to 4%, slowing recovery. If mortality from poisoned baits could be removed, the kite population could potentially increase at a rapid annual rate of 12%. The effects are somewhat higher if ingestion of these substances additionally causes sublethal reproductive impairment. These results have uncertainty but suggest that declining or recovering populations are most sensitive to lead shot or poison ingestion, and removal of poisoned baits can have a positive impact on recovering raptor populations that frequently feed on carrion.     

Docosahexaenoic acid homeostasis,brain aging and Alzheimer's disease: Can we reconcile the evidence?

A crossroads has been reached on research into docosahexaenoic acid (DHA) and Alzheimer's disease (AD). On the one hand, several prospective observational studies now clearly indicate a protective effect of higher fish and DHA intake against risk of AD. On the other hand, once AD is clinically evident, supplementation trials demonstrate essentially no benefit of DHA in AD. Despite apparently low DHA intake in AD, brain DHA levels are frequently the same as in controls, suggesting that low DHA intake results in low plasma DHA but does not necessarily reduce brain DHA in humans. Animal models involving dietary omega-3 fatty acid deficiency to deplete brain DHA may therefore not be appropriate in AD research. Studies in the healthy elderly suggest that DHA homeostasis changes during aging. Tracer methodology now permits estimation of DHA half-life in the human brain and whole body. Apolipoprotein E alleles have an important impact not only on AD but also on DHA homeostasis in humans. We therefore encourage further development of innovative approaches to the study of DHA metabolism and its role in human brain function. A better understanding of DHA metabolism in humans will hopefully help explain how higher habitual DHA intake protects against the risk of deteriorating cognition during aging and may eventually give rise to a breakthrough in the treatment of AD.     

Can we build synthetic,multicellular systems by controlling developmental signaling in space and time?

Using biological machinery to make new, functional molecules is an exciting area in chemical biology. Complex molecules containing both 'natural' and 'unnatural' components are made by processes ranging from enzymatic catalysis to the combination of molecular biology with chemical tools. Here, we discuss applying this approach to the next level of biological complexity -- building synthetic, functional biotic systems by manipulating biological machinery responsible for development of multicellular organisms. We describe recent advances enabling this approach, including first, recent developmental biology progress unraveling the pathways and molecules involved in development and pattern formation; second, emergence of microfluidic tools for delivering stimuli to a developing organism with exceptional control in space and time; third, the development of molecular and synthetic biology toolsets for redesigning or de novo engineering of signaling networks; and fourth, biological systems that are especially amendable to this approach.     

Can Community Health Workers Report Accurately on Births and Deaths? Results of Field Assessments in Ethiopia,Malawi and Mali

Introduction

Most low-income countries lack complete and accurate vital registration systems. As a result, measures of under-five mortality rates rely mostly on household surveys. In collaboration with partners in Ethiopia, Ghana, Malawi, and Mali, we assessed the completeness and accuracy of reporting of births and deaths by community-based health workers, and the accuracy of annualized under-five mortality rate estimates derived from these data. Here we report on results from Ethiopia, Malawi and Mali.

Method

In all three countries, community health workers (CHWs) were trained, equipped and supported to report pregnancies, births and deaths within defined geographic areas over a period of at least fifteen months. In-country institutions collected these data every month. At each study site, we administered a full birth history (FBH) or full pregnancy history (FPH), to women of reproductive age via a census of households in Mali and via household surveys in Ethiopia and Malawi. Using these FBHs/FPHs as a validation data source, we assessed the completeness of the counts of births and deaths and the accuracy of under-five, infant, and neonatal mortality rates from the community-based method against the retrospective FBH/FPH for rolling twelve-month periods. For each method we calculated total cost, average annual cost per 1,000 population, and average cost per vital event reported.

Results

On average, CHWs submitted monthly vital event reports for over 95 percent of catchment areas in Ethiopia and Malawi, and for 100 percent of catchment areas in Mali. The completeness of vital events reporting by CHWs varied: we estimated that 30%-90% of annualized expected births (i.e. the number of births estimated using a FPH) were documented by CHWs and 22%-91% of annualized expected under-five deaths were documented by CHWs. Resulting annualized under-five mortality rates based on the CHW vital events reporting were, on average, under-estimated by 28% in Ethiopia, 32% in Malawi, and 9% in Mali relative to comparable FPHs. Costs per vital event reported ranged from $21 in Malawi to $149 in Mali.

Discussion

Our findings in Mali suggest that CHWs can collect complete and high-quality vital events data useful for monitoring annual changes in under-five mortality rates. Both the supervision of CHWs in Mali and the rigor of the associated field-based data quality checks were of a high standard, and the size of the pilot area in Mali was small (comprising of approximately 53,205 residents in 4,200 households). Hence, there are remaining questions about whether this level of vital events reporting completeness and data quality could be maintained if the approach was implemented at scale. Our experience in Malawi and Ethiopia suggests that, in some settings, establishing and maintaining the completeness and quality of vital events reporting by CHWs over time is challenging. In this sense, our evaluation in Mali falls closer to that of an efficacy study, whereas our evaluations in Ethiopia and Malawi are more akin to an effectiveness study. Our overall findings suggest that no one-size-fits-all approach will be successful in guaranteeing complete and accurate reporting of vital events by CHWs.     

Hippocampus and memory. Can we have our place and fear it too?

Theories of hippocampal function are often split into cognitive map theories and relational/episodic memory theories. In this issue of Neuron, show that hippocampal cells respond to the combination of spatial location and conditioned stimuli in a nonspatial fear conditioning task, suggesting a potential bridge between the competing theories of hippocampal function.     

Can Infants Tell the Difference between Gold and Yellow?

There is a large literature focused on the color perception of matte surface. However, recent research showed that the component of surface specular reflection, such as glossiness, also affects categorical color perception. For instance, the color term “gold” was used to name high specular stimuli within a specific range of chromaticity, which overlaps with those of yellow and orange for low specular stimuli. In the present study, we investigated whether the component of surface specular reflectance affects the color perception of 5- to 8-month-old infants by using the preferential looking technique. In the first experiment, we conducted a simple test to determine whether infants perceive yellow and gold as the same color by comparing their preference for these colors over green. If the infants perceive yellow and gold as the same color, they would show similar preference scores over green. On the other hand, if infants show different preference scores over green, it indicates that infants do not perceive yellow and gold as the same color. Only the 7–8 month-old infants showed different preference scores for gold and yellow over green. This result indicates that the 7–8 month-old infants perceive gold and yellow as different colors. In Experiment 2, we eliminated the component of specular reflectance on the gold surface and presented it against green to infants. A similar preference score of yellow over green was obtained. This result suggests that the difference between the preference scores for gold and yellow over green in Experiment 1 was based on representations of glossiness.