Can you still see the cochlea for the molecules?

It is now established that the mammalian cochlea uses active amplification of incoming sound to achieve sensitivity. Cellular details are emerging slowly. Recent studies of sensory hair cells have highlighted the possible molecular bases for amplification and the components of sensitivity regulation within the cochlea: a synthesis is likely to depend on effective and physiologically informed modelling.     

Is the significance of race declining in the political arena? Yes,and no

The significance of class is increasing in the USA, in the sense that economic inequality is rising within the black and Latino populations as well as among whites. Growing inequality is associated with increasing disparities in lived experiences. Is class also increasingly significant in political life? Survey evidence shows that the answer is yes: compared with previous decades, well-off blacks and Latinos are less strongly liberal in some policy preferences and feel more politically efficacious, while poor blacks and Latinos tend to move in the opposite direction. Well-off non-whites have not, however, lost any commitment to racial justice or identity, so the USA is not becoming ‘post-racial’. Given the complex patterns of change and persistence in opinions, Wilson's arguments about when and how race is significant remain as important and controversial as when first expressed.     

Can you imagine the LCA world without our journal?

Editorial: To the LCA Community

Can you imagine the LCA world without our journal?     

Optimal radio-tracking strategy — The best results with the least effort?

We tested the need to radio-track nocturnal mammals, such as raccoon dogsNyctereutes procyonoides (Gray, 1834) and badgersMeles meles (Linnaeus, 1758), throughout the night for reliable estimates of home range size and habitat selection. We also tested the possibility to reduce the tracking effort by decreasing the number of tracking-nights. The results indicated that the locations collected before midnight gave good estimates of home range sizes but those collected after midnight or by reducing the number of tracking-nights resulted in smaller home ranges than those estimated using the total data. Thus, if one aims to estimate only the home range size, locations before midnight would be adequate. Locations of raccoon dogs taken only before or after midnight did not reveal all habitats, which were favoured on the basis of the total data. Although locations of badgers before midnight seemed to give correct results of habitat selection, we recommend radio-tracking also badgers at least few times through the night, because their core areas shifted during the night. In the case of badgers, but not of raccoon dogs, we obtained correct results of habitat selection by reducing the tracking effort by decreasing the number of tracking-nights.     

Nevill's explanation of Kleiber's 0.75mass exponent: an artifact of collinearity problems in least squares models?

Batterham, Alan M., Keith Tolfrey, and Keith P. George.Nevill's explanation of Kleiber's 0.75 mass exponent: anartifact of collinearity problems in least squares models?J. Appl. Physiol. 82(2): 693-697, 1997.Intraspecific allometric modeling(Y = a ^· mass^b,where Y is the physiological dependentvariable and a is the proportionalitycoefficient) of peak oxygen uptake(O_{2 peak}) hasfrequently revealed a mass exponent(b) greater than that predicted fromdimensionality theory, approximating Kleiber's 3/4 exponent for basalmetabolic rate. Nevill (J. Appl.Physiol. 77: 2870-2873, 1994) proposed anexplanation and a method that restores the inflated exponent to theanticipated 2/3. In human subjects, the method involves the addition of"stature" as a continuous predictor variable in a multiplelog-linear regression model: ln Y = lna + c ^· ln stature + b ^· ln mass + ln, where c is the general body sizeexponent and  is the error term. It is likely thatserious collinearity confounds may adversely affect the reliability and validity of the model. The aim of this study was tocritically examine Nevill's method in modelingO_{2 peak} inprepubertal, teenage, and adult men. A mean exponent of 0.81 (95%confidence interval, 0.65-0.97) was found when scaling by massalone. Nevill's method reduced the mean mass exponent to 0.67 (95%confidence interval, 0.44-0.9). However, variance inflation factors and tolerance for the log-transformed stature and mass variables exceeded published criteria for severe collinearity. Principal components analysis also diagnosed severe collinearity in twoprincipal components, with condition indexes >30 and variance decomposition proportions exceeding 50% for two regressioncoefficients. The derived exponents may thus be numerically inaccurateand unstable. In conclusion, the restoration of the mean mass exponentto the anticipated 2/3 may be a fortuitous statistical artifact.

     

Can the Antarctic terrestrial midge,Eretmoptera murphyi,tolerate life in water?

1. Early‐season flooding and ice entrapment at sub‐zero temperatures pose significant challenges to any polar terrestrial invertebrate. 2. The chironomid midge, Eretmoptera murphyi, is native to the sub‐Antarctic island of South Georgia and has been introduced to the maritime Antarctic (Signy Island). While the majority of its 2‐year life cycle is spent as a terrestrial larva, it is found in habitats potentially exposed to prolonged flooding. 3. The current study explored the tolerance of the larvae to extended submergence, demonstrating survival for at least 28 days, underlain by their ability to respire (oxy‐regulate) whilst submerged. To date, this ability is not known to be shared by any other terrestrial midge. Larvae also demonstrated notable anoxia tolerance whilst encased in ice, surviving for up to 28 days. 4. These data indicate a capacity to survive ecologically relevant periods of submergence and/or ice entrapment, such as may be experienced in their natural habitats.     

Can the parthenogenetic marbled crayfish Marmorkrebs compete with other crayfish species in fights?

The parthenogenetic marbled crayfish, Marmorkrebs, has no known wild population, but has been introduced into natural ecosystems in two continents. Interactions with native crayfish, particularly through fighting, could affect the ecological impact of Marmorkrebs introductions. Marmorkrebs have been characterized anecdotally as having low levels of aggression, which could mitigate their potential to compete with native species. We isolated Marmorkrebs and Louisiana red swamp crayfish (Procambarus clarkii), then conducted size-matched intra and interspecific pairings. Marmorkrebs were as likely to win a fight as P. clarkii, although contests between P. clarkii and Marmorkrebs began significantly faster than contests between two Marmorkrebs. These results suggest that Marmorkrebs have the potential to compete with other species on the same level as P. clarkii, which is itself a highly successful introduced species around the world.     

Out with the old,in with the new? Comparing methods for measuring protein degradation

Protein degradation is a critical factor in controlling cellular protein abundance. Here, we compare classical methods for determining protein degradation rates to a novel GFP (green fluorescent protein) fusion protein based method that assesses the intrinsic stability of cloned cDNA library products by flow cytometry [Yen et al. (2008) Science 322, 918]. While no method is perfect, we conclude that chimeric gene reporter approaches, though powerful, should be applied cautiously, due principally to GFP (or other reporter tag) interference with protein organelle targeting or incorporation into macromolecular assemblies, both of which cause spuriously high degradation rates.     

The standard of neutrality: still flapping in the breeze?

Neutrality plays an important role as a null model in evolutionary biology. Recent theoretical advances suggest that neutrality is not a unitary concept, and we identify three distinct forms of neutrality. Eu‐neutrality means that types do not differ in any measurable way and is thus the idealized form of neutrality. However, individuals or species that do differ in important ways can behave neutrally under some circumstances, both broadening and complicating the applicability of the concept of neutrality. Our second two types of neutrality address two quite different forms of context‐dependent neutrality. Circum‐neutrality means that two character states have the same direct effect on fitness but do not evolve neutrally because of differences in their circumstances. Iso‐neutrality means that two types are equivalent in some population or ecological contexts but not in others, producing an isocline. Confounding of these different definitions has created significant confusion about which models are truly neutral, why some models behave neutrally even when there are large differences in reproductive outputs, and what these different views of neutrality mean to practicing biologists. These complications call into question the acceptance of neutral models as null models and suggest that a better approach is to compare the predictions of models that differ in sources of stochasticity and degree of selection.     

Can AMP induce sputum eosinophils,even in subjects with complete asthma remission?

Background

The definition of "clinical asthma remission" is based on absence of symptoms and use of medication. However, in the majority of these subjects airway inflammation is still present when measured. In the present study we investigated whether "complete asthma remission", additionally defined by the absence of bronchial hyperresponsiveness (BHR) and the presence of a normal lung function, is associated with the absence of airway inflammation.

Methods

Patients with a former diagnosis of asthma and a positive histamine provocation test were re-examined to identify subjects with complete asthma remission (no asthma symptoms or medication, PC₂₀ histamine > 32 mg/ml, FEV₁ > 90% predicted). Patients with PC₂₀ histamine ≤ 32 mg/ml were defined as current asthmatics and were divided in two groups, i.e. asthmatics with and without BHR to adenosine 5''monophoshate (AMP). Sputum induction was performed 1 week before and 1 hour after AMP provocation. Sputum induction and AMP provocation were previously shown to be sensitive markers of airway inflammation.

Results

Seven patients met criteria for complete asthma remission. Twenty-three were current asthmatics, including twelve without hyperresponsiveness to AMP. Subjects with complete asthma remission showed no AMP-induced sputum eosinophilia (median (range) 0.2 (0 - 4.6)% at baseline and 0.2 (0 - 2.6)% after AMP). After AMP, current asthmatics had a significant increase in sputum eosinophils (0.5 (0 - 26.0)% at baseline and 2.6 (0 - 32.0) % after AMP), as had the subgroup of current asthmatics without hyperresponsiveness to AMP (0.2 (0 - 1.8)% at baseline and 1.3 (0 - 6.3)% after AMP).

Conclusions

Subjects with complete asthma remission, in contrast to subjects with current asthma, do not respond with eosinophilic inflammation in sputum after AMP provocations. These data lend support to the usefulness of the definition of complete asthma remission.     

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 genomics clarify the origins of Boreioglycaspis melaleucae in California,USA?

The Australian psyllid Boreioglycaspis melaleucae is a biological control agent of Melaleuca quinquenervia in Florida (USA) but was observed attacking M. quinquenervia trees in southern California (USA). Genotyping revealed the California population matched three of eight Australian haplotypes and all three Florida haplotypes. It remains unclear if the California psyllid population arrived directly from Australia or via Florida.     

Can intact liposomes be absorbed in the gut?

Inulin, EDTA, or maltose were given intragastrically to mice, either free or entrapped in mono-shell liposomes of egg phosphatidylcholine or the non-digestible diether and dialkyl analog of phosphatidylcholine. Results indicate that liposomes may protect a drug from premature digestion but cannot carry it through the intestinal wall.     

Can Physiological Endpoints Improve the Sensitivity of Assays with Plants in the Risk Assessment of Contaminated Soils?

Site-specific risk assessment of contaminated areas indicates prior areas for intervention, and provides helpful information for risk managers. This study was conducted in the Ervedosa mine area (Bragança, Portugal), where both underground and open pit exploration of tin and arsenic minerals were performed for about one century (1857 – 1969). We aimed at obtaining ecotoxicological information with terrestrial and aquatic plant species to integrate in the risk assessment of this mine area. Further we also intended to evaluate if the assessment of other parameters, in standard assays with terrestrial plants, can improve the identification of phytotoxic soils. For this purpose, soil samples were collected on 16 sampling sites distributed along four transects, defined within the mine area, and in one reference site. General soil physical and chemical parameters, total and extractable metal contents were analyzed. Assays were performed for soil elutriates and for the whole soil matrix following standard guidelines for growth inhibition assay with Lemna minor and emergence and seedling growth assay with Zea mays. At the end of the Z. mays assay, relative water content, membrane permeability, leaf area, content of photosynthetic pigments (chlorophylls and carotenoids), malondialdehyde levels, proline content, and chlorophyll fluorescence (F_v/F_m and Φ_PSII) parameters were evaluated. In general, the soils near the exploration area revealed high levels of Al, Mn, Fe and Cu. Almost all the soils from transepts C, D and F presented total concentrations of arsenic well above soils screening benchmark values available. Elutriates of several soils from sampling sites near the exploration and ore treatment areas were toxic to L. minor, suggesting that the retention function of these soils was seriously compromised. In Z. mays assay, plant performance parameters (other than those recommended by standard protocols), allowed the identification of more phytotoxic soils. The results suggest that these parameters could improve the sensitivity of the standard assays.     

So, you want to work in industry?

Once upon a time ... Industry was seen as a poor second choice for those who could not find a niche in academia. That time has passed and an increasing amount of leading-edge research is done in the laboratories of Industry. So what is it like in the world of Industry--and what sort of biologists does Industry need?