Is asparagine deamidation in the porcine odorant-binding protein related to the odor molecules binding?

Odorant-binding proteins are biomolecules belonging to the lipocalin family. Among all the odorant-binding proteins, the porcine odorant-binding protein has been well characterized. This protein is a monomer that is characterized by the presence of the beta-barrel structure and of the disulphide bridge. The internal cavity of the beta-barrel is the binding site. In this study we have investigated the structural properties of the porcine odorant-binding protein by mass spectrometry experiments. Our data allow us to hypothesize that specific deamidation mechanisms of specific amino acid residues can be responsible for the binding properties of this class of proteins.     

Can life-history traits predict the response of forb populations to changes in climate variability?

1.  Climate change will cause changes in average temperature and precipitation as well as increased fluctuations around the mean, yet few studies have considered the impacts of altered climate variability on plant populations. We tested whether life-history traits (expected life span, generation time and seed size) can predict plant responses to increased environmental variability across similar plant species sharing the same habitat.
2.  We combined long-term demographic data on 10 prairie forb species with stochastic demography techniques to estimate the effects of potential changes in matrix element means and variances on the long-term stochastic population growth rate.
3.  For all 10 species, recruitment had higher contribution and elasticity values than survival, meaning that climate change is more likely to influence population growth through effects on recruitment than on survival for these relatively short-lived forbs. Species with longer generation times had lower elasticities to increases in matrix element variability.
4.   Synthesis. Our analysis of a unique, long-term data set suggests that longer-lived plant species will be less vulnerable to the effects of future increases in climate variability. While this relationship was previously reported for diverse taxa from many locations, our results show that it also applies within a guild of short-lived species from a single community. The generality of the pattern demonstrates the potential for using life-history traits to make predictions about which species may be the most vulnerable to climate change.     

Is catalase activity one of the factors associated with maize resistance to Aspergillus flavus?

Plant responses to biotic and abiotic stresses are usually accompanied by the release of reactive oxygen species including hydrogen peroxide. Hydrogen peroxide plays a direct role in defense and is involved in many signal transduction pathways that lead to the proliferation of other defenses. Because catalase helps to maintain reactive oxygen homeostasis during biotic and abiotic stress, its activity was measured in various cob tissues during maize ear development. Catalase activity was determined in immature and mature embryos, pericarp, and rachis tissues of maize lines that are resistant and susceptible to Aspergillus flavus infection. The effect of fungal inoculation on catalase activity was also measured. Over two years of field experimentation, a correlation was observed between resistance and the level of catalase-specific activity in immature embryos, which was significantly higher in resistant lines (P < 0.0001). Furthermore, catalase activity in the resistant lines was significantly higher in immature embryos from inoculated ears (P = 0.0199). No correlation was observed between resistance and catalase activity in other ear tissues. Levels of hydrogen peroxide, the catalase substrate, and salicylic acid in the embryo were also determined. The resistant lines showed lower levels of H2O2 (P < 0.0001) and higher levels of salicylic acid (P < 0.0001) as compared with the susceptible lines. Catalase 3 was sequenced from the aflatoxin-resistant (Mp313E) and susceptible (SC212m) inbreds. The predicted amino acid sequence indicated that there was a 20-aa deletion in the resistant inbred that might affect enzymatic activity. Unlike many plant-pathogen interactions, it appears that lowering H2O2 levels helps to prevent A. flavus infection and subsequent aflatoxin accumulation.     

Is serum protein electrophoresis useful in separating the "high risk group" in patients with colonic polyps?

BACKGROUND: Adenomas have the highest potential or clinical value from among colonic polyps of developing into adenocarcinoma. The aims of this paper are: to establish criteria to identify the high risk group of patients in a group of patients with colonic polyps, to work out a simple scheme for follow-up care after endoscopic polypectomy, and to establish indications for surgery. The usefulness of determination of electrophoresis of serum proteins has been specially analysed to detect early development of malignant growths in patients with colonic polyps regarding alfa-1/alfa-2 and alfa/beta. 67 cases - 21 women, 46 men were tested. Follow-up endoscopy with the electrophoresis was performed after 6 weeks, 6 and 12 months after polypectomy. 97 polyps were resected with endoscopy in 67 patients. 38 patients (39.17%), those constituting the high risk group, were selected. Included were all polyps with grade II and III of cellular differentiation. CONCLUSIONS: 1) alfa-1/alfa-2 and alfa/beta is a helpful test in identifying the high risk group among patients with colonic polyps and it can be used as a screening test, 2) the determination of beta-2-macroglobuline is not useful in the diagnosis of this group of patients, 3) the electrophoresis of proteins should be the first test to perform on patients with colonic polyps. The relation of electrophoresis to endoscopic polypectomy aids evaluations of patients specially predisposed to malignant.     

Is cell-mediated immunity related to the evolution of life-history strategies in birds?

According to life-history theory, the development of immune function should be balanced through evolutionary optimization of the allocation of resources to reproduction and through mechanisms that promote survival. We investigated interspecific variability in cell-mediated immune response (CMI), as measured by the phytohaemagglutinin (PHA) assay, in relation to clutch size, longevity and other life-history traits in 50 species of birds. CMI exhibited significant repeatability within species, and PHA responses in chicks were consistently stronger than in adults. Univariate tests showed a variety of significant relationships between the CMI of both chicks and adults with respect to size, development period and lifespan, but not clutch size or prevalence of blood parasites in adults. Multivariate analyses confirmed these patterns but independent variables were too highly correlated to isolate unique influences on CMI. The positive relationship of chick CMI to nestling period is further complicated by a parallel relationship of chick CMI to the age at testing. However, multivariate analysis showed that chick CMI varies uniquely with length of the nestling period. Adult CMI was associated with a strong life-history axis of body size, development rate and longevity. Therefore, adult CMI may be associated with prevention and repair mechanisms related to long lifespan, but it also may be allometrically related to body size through other pathways. Neither chick CMI nor adult CMI was related to clutch size, contradicting previous results linking parasite-related mortality to CMI and the evolution of clutch size (reproductive investment) in birds.     

Is A163G polymorphism in the osteoprotegerin gene associated with heel velocity of sound in postmenopausal women?

Osteoprotegerin (OPG) plays an important inhibitory role in osteoclastogenesis. Polymorphisms in the OPG gene recently have been associated with various bone phenotypes including fractures. The aim of the present study was to investigate the association between three informative OPG polymorphisms and quantitative ultrasound variables of the heel. In a cohort of 165 perimenopausal women polymorphisms in the OPG promoter (A163G, T245G) and in exon 1 (G1181C) were assessed by PCR-RFLP analysis. The distribution of the investigated genotypes was similar to other Caucasian women (A163G-AA 68 %, AG 30 %, GG 2 %, T245G-TT 84.4 %, TG 15 %, GG 0.6 %, G1181C- GG 22 %, CG 55 %, CC 23 %). After adjustment for body mass index and years since menopause, in a subgroup of 87 postmenopausal subjects, calcaneal velocity of sound (VOS, m/s) was significantly associated with A163G polymorphism (p=0.0102, ANCOVA). Women with the presence of G allele (AG+GG genotypes) had significantly lower VOS than women with AA genotype. Neither T245G nor G1181C were associated with calcaneal ultrasound indices. In conclusion, A163G polymorphism was significantly associated with VOS at the heel in a limited cohort of postmenopausal women. The present study replicated in part the previous findings about OPG gene variations and peripheral bone mass in Caucasian women.     

Is the cellular response to cigarette smoke predictive of the phenotypic variation of COPD?

The adverse health consequences of cigarette smoking are not limited to the lung but also include effects on multiple other organ systems that are exposed directly or indirectly to the hazardous gaseous and soluble compounds generated by burning tobacco. Cigarette smoking (CS) is a risk factor for many major diseases including chronic obstructive pulmonary disease (COPD), atherosclerosis, cerebral and coronary vascular diseases, hypertension, and many types of cancer. Within the diagnosis category of COPD, it is widely recognized that there is substantial phenotypic heterogeneity with respect to both pulmonary and extrapulmonary manifestations. To understand the variability in responses to CS, it becomes essential to decipher the involved mechanisms at a cellular and molecular level that contribute to cigarette-related pathology. In this issue of the Journal, there are three papers (1, 4, 6) that provide insight regarding the molecular pathogenesis of CS-related COPD that could be related to phenotypic variation, by examining three classes of cell types of lung: endothelial cells, epithelial cells, and immune effector cells.     

Where to invest in road mitigation? A comparison of multiscale wildlife data to inform roadway prioritization

Roads and associated traffic have significant impacts on wildlife, from direct mortality caused by vehicle collisions to indirect effects when wildlife avoid roads, restricting access to important resources. Road mitigation measures such as constructing wildlife passages over or under the road with directional fencing have proven effective at reducing wildlife vehicle collisions while also enabling wildlife to safely cross the road. Highway mitigation projects are led by transportation agencies with a primary purpose of improving motorist safety. More recently, through the discipline of road ecology, considerations have included safe wildlife passage through transportation corridors. To prioritize road sections for mitigation, data sources include animal vehicle collision data collected by transportation agencies and connectivity models generated by wildlife professionals. We used a third data source, pronghorn observations collected by citizen scientists, and demonstrated its value to prioritize potential wildlife mitigation sites. Our results clearly demonstrate a misalignment of road mitigation sites using animal-vehicle collision data and those of rarer species of interest.     

What works in the field? A comparison of different interviewing methods in ethnobotany with special reference to the use of photographs

Ethnobotanists use a variety of interview techniques to collect ethnobotanical data. Drawing upon the results from a quantitative ethnobotanical study in five Yuracaré and Trinitario communities in the Bolivian Amazon, the pros and cons of the following methods are evaluated: (1) interviews in situ during transects, walk-in-the-woods, and homegarden sampling; and (2) interviews ex situ with fresh plant material, voucher specimens, or plant photographs as reference tools. Although the systematic use of plant photographs for ethnobotanical interviews is poorly documented in literature, the results show that indigenoùs participants in our study recognize significantly more plant species from photographs than from voucher specimens. It is argued that, especially in remote and isolated study sites, photographs might be advantageous over voucher specimens.     

Can the fluorescence of green fluorescent protein chromophore be related directly to the nativity of protein structure?

In studies of green fluorescence protein (GFP) or other proteins with the use of GFP as a marker, the fluorescence of GFP is for the most part related directly to the nativity of its structure. Naturally, such a relation does exist since the chromophore of this protein is formed autocatalytically only just after GFP acquires its native structure. However, the fluorescence method may not yield reliable information on protein structure when studying renaturation and denaturation of this protein (with the formed chromophore). Using proteolysis, denaturant gradient gel electrophoresis and circular dichroism, we demonstrate herein that at major disturbances of the native structure of protein GFP-cycle3 the intensity of fluorescence of its chromophore can change insignificantly. In other words, the chromophore fluorescence does not reliably mirror alterations in protein structure. Since the main conclusions of this study are especially qualitative, it can be suggested that during renaturation/denaturation of wild-type GFP and its “multicolored” mutants their fluorescence is also not always associated with the changes in the structure of these proteins.     

Porcine SPP1 gene polymorphism association with phenotypic traits in the Landrace?×?Jeju (Korea) black pig F2 population

This study examined polymorphisms of the secreted phosphoprotein 1 (SPP1) gene and its association with growth and carcass traits in the F(2) population of the crossbred Landrace × Jeju (Korea) Black pig. The authors detected the presence/absence polymorphisms of short interspersed nuclear element in the SPP1 intron 6 of the population; they then designated the longer fragment as allele A and the shorter one as allele B. The SPP1 A/B heterozygous pigs evidenced significantly heavier body weight at birth and on days 21 and 70, and a higher level of average daily gain during the early developmental period than was seen in the A/A and B/B homozygous pigs (P < 0.05). Further, the SPP1 A/B heterozygous pigs evidenced significantly greater body length, less backfat thickness measured at three different sites, and larger loin muscle area than the homozygotes (P < 0.05). On the other hand, the levels of late average daily gain, 140th-day body weight, and marbling score were not significantly associated (P > 0.05). The results of this study reveal faster growth rate and differences in pig productivity according to genotypes of the SPP1 gene. These findings demonstrate that SPP1 genotypes may effectively function as molecular genetic markers for the improvement of Jeju Black pig-related crossbreeding systems.     

Is health status of elderly worsening in India? A comparison of successive rounds of national sample survey data

The increasing greying of India's population raises concerns about the welfare and health status of the aged. One important source of information of health status of the elderly is the National Sample Survey Rounds on Morbidity and Health Care Expenditure. Using unit-level data for 1995-96 and 2004, this paper examines changes in reported health status of the elderly in India and analyses their relationship with living arrangements and extent of economic dependency. It appears that even after controlling for factors like caste, education, age, economic status and place of residence, there has been a deterioration in self-perceived current health status of the elderly. The paper argues that, although there have been changes in the economic condition and traditional living arrangements--with a decline in co-residential arrangements--this is not enough to explain the decline in reported health status and calls for a closer look at narratives of neglect being voiced in developing countries.     

Can genetic variability for nitrogen metabolism in the developing ear of maize be exploited to improve yield?

Quantitative trait loci (QTLs) for the main steps of nitrogen (N) metabolism in the developing ear of maize (Zea mays L.) and their co-localization with QTLs for kernel yield and putative candidate genes were searched in order to identify chromosomal regions putatively involved in the determination of yield. During the grain-filling period, the changes in physiological traits were monitored in the cob and in the developing kernels, representative of carbon and N metabolism in the developing ear. The correlations between these physiological traits and traits related to yield were examined and localized with the corresponding QTLs on a genetic map. Glycine and serine metabolism in developing kernels and the cognate genes appeared to be of major importance for kernel production. The importance of kernel glutamine synthesis in the determination of yield was also confirmed. The genetic and physiological bases of N metabolism in the developing ear can be studied in an integrated manner by means of a quantitative genetic approach using molecular markers and genomics, and combining agronomic, physiological and correlation studies. Such an approach leads to the identification of possible new regulatory metabolic and developmental networks specific to the ear that may be of major importance for maize productivity.     

Is heat shock protein re-induction during tolerance related to the stressor-specific induction of heat shock proteins?

The existence of stressor-specific induction programs of heat shock proteins (hsps) leads us to analyze the possible occurrence of a stressor-specific tolerance induced by either heat shock, arsenite, or cadmium. As a measure of this tolerance re-induction of hsps was studied. In this paper, we tested whether the refractory state is either valid for each specific hsp (implying independent regulation of every member of the heat shock protein family) or extends from small subsets of the hsp-family to even larger groups of proteins (indicating a more common denominator in their regulation). (Re-)induction of hsps does not seem to be regulated at the level of each individual hsp since differences in induced synthesis of hsps between two stressor conditions are not supplemented systematically upon the sequential application of the two stressors. The most notable example in this respect is hsp60. A pretreatment with cadmium, which hardly induces synthesis of this hsp, does induce a tolerance to (re)-induction by heat shock, which normally induces hsp60. This suggests the existence of a more common denominator regulating the coordinate expression of at least some hsps. From our data we conclude that the degree, but not the pattern, of hsp re-induction is influenced by the type of stressor used in the pretreatment. The pattern of hsps induced by a secondary applied stressor still shows most of its stressor-specificity and seems to be independent of any pretreatment. The possible implications of stressor-specificity are discussed. © 1996 Wiley-Liss, Inc.     

Do McKinnon lists provide reliable data in bird species frequency? A comparison with transect-based data

Although occurrence-based listing methods could provide reliable lists of species composition for a site, the effective reliability of this method to provide more detailed information about species frequency (and abundance) has been rarely tested. In this paper, we compared the species frequencies obtained for the same set of species-rich sites (wetlands of central Italy) from two different methods: McKinnon lists and line transects. In all sites we observed: (i) rapid cumulating curves of line transect abundance frequencies toward the asymptote represented by the maximum value in McKinnon occurrence frequency; (ii) a large amount of species having a low frequency with line transect method showing a high range of variation in frequency obtained by McKinnon lists; (iii) a set of species having a subdominant (>0.02-<0.05) and dominant species (>0.05) frequency with line transect showed all the highest value in McKinnon frequency. McKinnon lists provides only a coarse-grained proxy of species frequency of individuals distinguishing only between common species (having the highest values of McKinnon frequency) and rare species (all the other species). Although McKinnon lists have some points of strength, this method does not discriminate the frequencies inside the subset of common species (sub-dominant and dominant species). Therefore, we suggest a cautionary approach when McKinnon frequencies should be used to obtain complex univariate metrics of diversity.     

Are secondary sex traits, parasites and immunity related to variation in primary sex traits in the Arctic charr?

Primary and secondary sex traits are influenced by the same sex hormones, and the expression of secondary sex traits may consequently signal males' capacity for sperm production. Sperm quality may also be influenced by immune activity, as sperm are non-self to the male. Parasite infections alter immune activity and may thus reduce ejaculate quality. In the Arctic charr (Salvelinus alpinus) the red abdominal colour is considered an ornament that signals important information in mate choice. We captured and individually caged sexually mature male Arctic charr during the spawning period. Afterwards we estimated abdominal colour, parasite infections, gonad mass and several spermatological and immunological variables. Intensity of abdominal colour was positively correlated to testes mass, milt mass and sperm cell numbers produced. Additionally, males with low parasite intensities had high testes mass and produced milt with high sperm density, indicating a trade-off between parasite resistance and development of primary sex traits. Our measures of immunity were, however, not related to primary sex traits. We conclude that females evaluating male abdominal coloration may obtain information about differences between males in fertilization potential and parasite resistance.     

Is community persistence related to diversity? A test with prairie species in a long-term experiment

Community persistence, or the ability of a community to maintain species composition and diversity through time, is a component of stability that is important to restoration. We ran a biodiversity–ecosystem functioning experiment for three years, and then stopped weeding it for 5–6 years, which allowed us to test whether increased plant species diversity and dissimilarity in height would lead to increased community persistence in the face of high invasion pressure by non-native species. Our approach was unique in that the experiment varied richness (one or four species) and evenness (three levels plus monocultures of the dominant species) using two separate dissimilarity types (having all tall species or having tall and short species combined) in six spatiotemporal blocks. Persistence was quantified as to how well positive productivity–diversity relationships, proportion of planted native species, and species richness remained unchanged over time. Thus, high persistence values indicate low levels of invasion and local extinction. We found that the positive relationship between diversity measures and productivity persisted after cessation of weeding. The proportion of planted species was 32% higher in mixture than in monoculture plots, indicating that monocultures were more heavily invaded by non-native species. Reduced evenness did not affect persistence measures in plots with dissimilar heights, but measures declined linearly with decreased evenness in plots with all tall species. Our results suggest that (1) persistence–diversity relationships are likely to vary with the traits of species becoming rare and going extinct, and (2) it is important to restore higher species diversity in restoration projects to favor the long-term persistence of planted species.