Strategies in identifying individuals in a segregant population of common bean and implications of genotype x environment interaction in the success of selection

The objective of this study was to compare the BLUP selection method with different selection strategies in F-2:4 and assess the efficiency of this method on the early choice of the best common bean (Phaseolus vulgaris) lines. Fifty-one F-2:4 progenies were produced from a cross between the CVIII8511 x RP-26 lines. A randomized block design was used with 20 replications and one-plant field plots. Character data on plant architecture and grain yield were obtained and then the sum of the standardized variables was estimated for simultaneous selection of both traits. Analysis was carried out by mixed models (BLUP) and the least squares method to compare different selection strategies, like mass selection, stratified mass selection and between and within progeny selection. The progenies selected by BLUP were assessed in advanced generations, always selecting the greatest and smallest sum of the standardized variables. Analyses by the least squares method and BLUP procedure ranked the progenies in the same way. The coincidence of the individuals identified by BLUP and between and within progeny selection was high and of the greatest magnitude when BLUP was compared with mass selection. Although BLUP is the best estimator of genotypic value, its efficiency in the response to long term selection is not different from any of the other methods, because it is also unable to predict the future effect of the progenies x environments interaction. It was inferred that selection success will always depend on the most accurate possible progeny assessment and using alternatives to reduce the progenies x environments interaction effect.

Characterization of Opsin Gene Alleles Affecting Color Vision in a Wild Population of Titi Monkeys (Callicebus brunneus)

The color vision of most platyrrhine primates is determined by alleles at the polymorphic X-linked locus coding for the opsin responsible for the middle- to long-wavelength (M/L) cone photopigment. Females who are heterozygous at the locus have trichromatic vision, whereas homozygous females and all males are dichromatic. This study characterized the opsin alleles in a wild population of the socially monogamous platyrrhine monkey Callicebus brunneus (the brown titi monkey), a primate that an earlier study suggests may possess an unusual number of alleles at this locus and thus may be a subject of special interest in the study of primate color vision. Direct sequencing of regions of the M/L opsin gene using feces-, blood-, and saliva-derived DNA obtained from 14 individuals yielded evidence for the presence of three functionally distinct alleles, corresponding to the most common M/L photopigment variants inferred from a physiological study of cone spectral sensitivity in captive Callicebus. Am. J. Primatol. 73:189-196, 2011. (C) 2010 Wiley-Liss, Inc.

A new population of the Cone-billed Tanager Conothraupis mesoleuca, with information on the biology, behaviour and type locality of the species

The `Critically Endangered` Cone-billed Tanager Conothraupis mesoleuca was described in 71 93 9, based on a single specimen collected in the state of Mato Grosso, western Brazil. Not seen again in the wild until 2003, this poorly-known species was rediscovered in Emas National Park, in the Brazilian state of Goias. We describe here the discovery of a new population of Cone-billed Tanager in Chapada dos Parecis, along the upper Juruena River basin, in the state of Mato Grosso. The birds were always detected in (or near) flooded habitats along rivers. At least 40 individuals were found, but the population may be larger since areas of potential habitat are available in the upper Juruena basin and these have not yet been surveyed. We also provide here the first information on the biology and behaviour of the species based on observations in Juruena and Emas, as well as a first description of the female. Historical documents and our records support our suggestion that ""Juruena"", i.e. the type locality of the Cone-billed Tanager, refers to the Juruena telegraph station (12 degrees 50`S, 58 degrees 55`W). Considering that the range of the species is being settled, research on different aspects of its biology are urgent.

Diverse levels of an inwardly rectifying potassium conductance generate heterogeneous neuronal behavior in a population of dorsal cochlear nucleus pyramidal neurons

Leao RM, Li S, Doiron B, Tzounopoulos T. Diverse levels of an inwardly rectifying potassium conductance generate heterogeneous neuronal behavior in a population of dorsal cochlear nucleus pyramidal neurons. J Neurophysiol 107: 3008-3019, 2012. First published February 29, 2012; doi:10.1152/jn.00660.2011.-Homeostatic mechanisms maintain homogeneous neuronal behavior among neurons that exhibit substantial variability in the expression levels of their ionic conductances. In contrast, the mechanisms, which generate heterogeneous neuronal behavior across a neuronal population, remain poorly understood. We addressed this problem in the dorsal cochlear nucleus, where principal neurons exist in two qualitatively distinct states: spontaneously active or not spontaneously active. Our studies reveal that distinct activity states are generated by the differential levels of a Ba2+-sensitive, inwardly rectifying potassium conductance (K-ir). Variability in K-ir maximal conductance causes variations in the resting membrane potential (RMP). Low K-ir conductance depolarizes RMP to voltages above the threshold for activating subthreshold-persistent sodium channels (Na-p). Once Na-p channels are activated, the RMP becomes unstable, and spontaneous firing is triggered. Our results provide a biophysical mechanism for generating neural heterogeneity, which may play a role in the encoding of sensory information.

Evaluation of the prevalence and nutritional and social determinants of overweight in a population of schoolchildren: a cross-sectional analysis of 5,037 children

Objective: To evaluate the prevalence and nutritional and social determinants of overweight in a population of schoolchildren in Southern Brazil. Methods: Cross-sectional descriptive study of 5,037 children of both genders, between 6 and 10.9 years of age, from public and private schools of Maringa, Parana, Brazil. Evaluation of factors associated with excess weight (overweight and obesity) included gender, age, school type, socioeconomic level, education of the head of the family, eating habits, and means of commuting to school. After univariate analysis (Fisher's exact test), we adjusted a logistic regression model and used Wald's test for decision-making (p < 0.05). Results: The mean age was 8.7 +/- 1.3 years, with 52.8% females; 79.1% of the students attended public school and 54.6% had families of socioeconomic class A or B. Regarding nutritional status, 24% of children were overweight (7% obesity, 17% overweight). Being male, attending a private school, and having a head of the family with over four years of education were significantly associated with excess weight. In relation to food, inadequate intake of,carbohydrates was associated with a 48% greater chance of overweight/obesity (p < 0.001; OR: 1.48; 95% CI: 1.25-1.76), Conclusion: The prevalence of overweight found in this study is approximate to that reported in national studies. Its association with gender and inadequate food intake indicates that these factors should be considered in initiatives aimed at preventive measures in childhood.

Reduced Population of Interstitial Cells of Cajal in Chagasic Megacolon

Background/Aims: In Chagasic megacolon, there is a reduction in the population of interstitial cells of Cajal. It was aimed to evaluate density of Cajal cells in the resected colon of Chagasic patients compared to control patients and to verify possible association between preoperative and postoperative bowel function of megacolon patients and cell count. Methodology: Sixteen megacolon patients (12 female; mean age 54.4 (31-73)) were operated on. Pre- and postoperative evaluation using Cleveland clinic constipation score was undertaken. Resected colons were examined. Cajal cells were identified by immunohistochemistry (anti-CD117). The mean cell number was compared to resected colons from 16 patients (7 female; mean age 62.8 (23-84)) with non-obstructive sigmoid cancer. Association between pre- and postoperative constipation scores and cell count for megacolon patients was evaluated using the Pearson test (r). Results: A reduced number of Cajal cells (per field: 2.84 (0-6.6) vs. 9.68 (4.3-13); p<0.001) were observed in the bowel of megacolon patients compared to cancer patients. No correlation between constipation score before (r=-0.205; p=0.45) or after surgery (r=0,291; p=0.28) and cell count in megacolon was observed. Conclusions: Patients with megacolon display marked reduction of interstitial cells of Cajal. An association of constipation severity and Cajal cells depopulation was not demonstrated.

Seasonal changes in the pigment composition of natural population of Gracilaria domingensis (Gracilariales, Rhodophyta)

The concentrations of phycobiliproteins (phycoerythrin and phycocyanin), chlorophyll-a and total soluble proteins were determined monthly in three strains (red, green and brown) of Gracilaria domingensis (Kützing) Sonder ex Dickie, collected from natural populations on the coast of Rio Grande do Norte, Brazil. In all the strains, pigment and protein concentrations were higher in the months of less sunlight and greater nitrogen availability and decreased gradually with increased sunlight and decreased nutrient concentration. The red strain showed higher concentrations of phycoerythrin and total soluble proteins. The difference in the concentration of biochemical components over the course of the year indicates species acclimation to different environmental conditions.

The unconventional secretion of stress-inducible protein 1 by a heterogeneous population of extracellular vesicles

The co-chaperone stress-inducible protein 1 (STI1) is released by astrocytes, and has important neurotrophic properties upon binding to prion protein (PrPC). However, STI1 lacks a signal peptide and pharmacological approaches pointed that it does not follow a classical secretion mechanism. Ultracentrifugation, size exclusion chromatography, electron microscopy, vesicle labeling, and particle tracking analysis were used to identify three major types of extracellular vesicles (EVs) released from astrocytes with sizes ranging from 20–50, 100–200, and 300–400 nm. These EVs carry STI1 and present many exosomal markers, even though only a subpopulation had the typical exosomal morphology. The only protein, from those evaluated here, present exclusively in vesicles that have exosomal morphology was PrPC. STI1 partially co-localized with Rab5 and Rab7 in endosomal compartments, and a dominant-negative for vacuolar protein sorting 4A (VPS4A), required for formation of multivesicular bodies (MVBs), impaired EV and STI1 release. Flow cytometry and PK digestion demonstrated that STI1 localized to the outer leaflet of EVs, and its association with EVs greatly increased STI1 activity upon PrPC-dependent neuronal signaling. These results indicate that astrocytes secrete a diverse population of EVs derived from MVBs that contain STI1 and suggest that the interaction between EVs and neuronal surface components enhances STI1–PrPC signaling

Population biology of Excirolana armata (Dana, 1853) (Isopoda, Cirolanidae) on an exposed sandy beach in Southeastern Brazil

The reproductive biology and population dynamics of the cirolanid isopod Excirolana armata (Dana, 1853) were analysed through monthly samples from December 2003 to November 2005 on Una beach, Sao Paulo state (24 degrees S), in Southeastern Brazil. Sampling was performed along three transects established from the base of foredunes to the waterline. On Una beach, E. armata showed continuous reproduction with higher abundances of ovigerous females in winter and spring (July-November) with a higher peak of juveniles in spring (November 2004). The fecundity ranged from 2 to 18 eggs/embryos per female, depending on the female length. The incubation period was estimated as 2 months. The life span of males and females was nearly 1 year. The short life span and the high energetic expenditure inherent to reproduction with maternal care, probably kept females from producing more than one brood in their lifetime. When comparing the population of E. armata on Una beach (24 degrees S) with populations in Southern Brazil (32 degrees S), Uruguay (34 degrees S) and Argentina (36 degrees S), it was verified that several biological population traits (length of the smallest juvenile, length of the largest individual, length of the smallest and largest ovigerous females, range of fecundity and life span) tended to increase at higher latitudes, whereas other traits (instantaneous rate of mortality and the curvature parameter of von Bertalanffy growth function) tended to decrease. However, comparing E. armata on Una beach (24 degrees S) with a population situated at a close latitude (25 degrees S), unexpected differences in relation to population structure and to growth demonstrated and reinforced the importance of density-dependent factors over life history traits of E. armata on dissipative beaches.

Allometry and population structure of Nicolea uspiana (Polychaeta: Terebellidae)

The relative growth and population structure of the terebellid Nicolea uspiana were investigated in the intertidal zone of a rocky shore on the south-east coast of Brazil, from May 2006 to May 2007. Eight hundred and forty-seven individuals of N. uspiana were analysed: 391 males, 163 females, and 293 immatures. Although significant differences in some morphometric parameters were found, there was no sexual dimorphism between males and females. There were differences in total length, width of segments, and length of the notopodial region between matures and immatures. The negative allometry of the total length in relation to five other parameters showed that this feature is a good measure for estimating the individual size, which was then used in the analysis of population structure. This population of N. uspiana showed a bimodal size frequency distribution, with immature and mature individuals found during the entire year. This pattern indicates continuous reproduction, with each cohort growing for at least three to four months and being responsible for two consecutive settlement peaks.

Population structure of the lancelet Branchiostoma caribaeum (Cephalochordata: Branchiostomidae) in the Baia de Guanabara, Rio de Janeiro, southeastern Brazil

Population structure of the lancelet Branchiostoma caribaeum Sandevall, 1853 was studied in four surveys, corresponding to austral seasons, in a tropical bay, southeast of Brazil. Abundance was higher in the spring and was positively correlated to coarse sediments, limiting its occurrence to some sectors of the sampling area. Body length and biomass differed seasonally but not between sexes. Sexually mature individuals occurred in all seasons, suggesting continuous breeding that is typical of tropical species. Variation in the frequency of small specimens indicates temporal differences in the intensity of breeding. The body length of recruits differed from other population of lancelets and the small length which B. caribaeum attained sexual maturity in Guanabara Bay may be related to local environmental stress or the great availability of food.

Relative abundance and population biology of the non-indigenous crab Charybdis hellerii (Crustacea: Brachyura: Portunidae) in a southwestern Atlantic estuary-bay complex

Invasive species are potential threats to biodiversity, especially if they become established and outnumber native species. In this study, a population of the non-indigenous crab Charybdis hellerii was analyzed in an estuary-bay complex on the southeastern Brazilian coast, with respect to its abundance relative to sympatric native brachyuran species, as well as the size structure, sexual maturity, sex ratio, frequency of mutilation, reproductive period, and development of the reproductive system. Crabs were sampled monthly both in the intertidal zone of rocky shores and on sublittoral soft-bottom. Nine species were recorded on the rocky shores, where C. hellerii was the second most abundant species; only three individuals of C. hellerii were collected in the sublittoral samples. This population of C. hellerii showed a unimodal size structure composed mainly of mature individuals; males were larger than females, and the sex ratio was skewed toward males (3.1:1). About 46.9% of the individuals (75 of 160 crabs) had mutilated or regenerating appendages, more frequent in males (56.8%) than in females (28.2%), which may reflect both inter- and intraspecific agonistic interactions. A continuous reproductive pattern is suggested for this population, although ovigerous females occurred unevenly during the year, with 58.82% of them being collected in winter. There was evidence of multiple spawning, since the ovigerous females with an initial egg mass showed mature ovaries as well as seminal receptacles filled with sperm. C. hellerii is well established in the estuary-bay complex, but is concentrated in intertidal and shallow subtidal rocky shores, where it may compete with and replace other species such as the portunid Cronius ruber. This study also highlights the importance of systematic monitoring studies to evaluate the effects of the introduction of non-indigenous species on ecologically similar natives.

Profile of Trypanosoma cruzi Reactivity in a Population at High Risk for Endemic Pemphigus Foliaceus (Fogo Selvagem)

Fogo Selvagem (FS) is an autoimmune bullous disease with pathogenic IgG autoantibodies recognizing desmoglein 1 (Dsg1), a desmosomal glycoprotein. In certain settlements of Brazil, a high prevalence of FS (3%) is reported, suggesting environmental factors as triggers of the autoimmune response. Healthy individuals from endemic areas recognize nonpathogenic epitopes of Dsg1, and exposure to hematophagous insects is a risk factor for FS. Fogo selvagem and Chagas disease share some geographic sites, and anti-Dsg1 has been detected in Chagas patients. Indeterminate Chagas disease was identified in a Brazilian Amerindian population of high risk for FS. In counterpart, none of the FS patients living in the same geographic region showed reactivity against Trypanosoma cruzi. The profile of anti-Dsg1 antibodies showed positive results in 15 of 40 FS sera and in 33 of 150 sera from healthy individuals from endemic FS sites, and no cross-reactivity between Chagas disease and FS was observed.

POPULATION DENSITY OF THE HELMETED CURASSOW (PAUXI PAUXI) IN TAMA NATIONAL PARK, COLOMBIA

We estimated the population density of the Helmeted Curassow (Pauxi pauxi) in Tama National Park (TNP) Colombia, using visual counts between December 2006 and December 2008. We used six line transects (1 km each) equitably distributed in a natural forest between 800 and 1,200 m asl in the southern part of the park. The sampling effort was 588 hrs with a total distance of 490 km, a detection rate of 0.06 records/hr, and an encounter rate of 0.08 individuals/km. Only solitary individuals were recorded (n = 40); the estimated density was 4.8 individuals/km(2). Most detections occurred in the lower strata of the forest (floor and sub-canopy) where hunters take advantage of curassows in the lower strata for successful harvest. The southern sector of TNP becomes important in the dry season. Our study suggests a large population is in TNP, but harvesting activities including removal of eggs, chicks, and juveniles, and hunting adults are affecting the reproductive rate and population of the species. Received 6 June 2011. Accepted 2 February 2012.

Clinical characteristics and possible phenotypes of an adult severe asthma population

Background: Currently, there are no studies of well-characterized severe asthmatics in Brazil. We aimed to study a population of severe treated asthmatics still uncontrolled to characterize them and define possible phenotypes. Methods: Descriptive cross-sectional outpatient study of severe asthmatics, evaluating functional and inflammatory markers, health-related quality of life, anxiety and depression symptoms, clinical control status, and characteristics related to atopy, age of asthma onset, induced sputum eosinophil levels, and airflow limitation. We also grouped the subgroups characteristics to identify phenotypes. The study is registered on ClinicalTrial.gov NCT 01089322. Results: From 128 eligible patients with severe/uncontrolled asthma, 74 fulfilled the inclusion criteria. The cohort was comprised of 85% women, frequently with a body mass index higher than 31 kg m(-2), atopy (60%), early-onset disease (50%), sputum eosinophilia (80%), comorbidities, and reduced quality of life. Nonatopics had significant higher asthma onset (19 y.a.) and twice level of induced sputum eosinophil. Late-onset patients had significantly less atopy (57%) and higher levels of induced sputum eosinophils. Non-eosinophilics had lower levels of inflammatory markers. Patients with airflow limitation had more intensive care unit admissions (56%) and 1.5 times more airway resistance. Subgroups characteristics identified a priori four well-characterized phenotypes, with 55% presenting sputum eosinophilia. Conclusion: Our data emphasize the high burden of disease, the persistence of inflammation and the existence of clinical possible phenotypes population sharing common features with published cohorts. Despite the necessity of further investigation into pathogenic mechanisms, this study with clinically difficult patient group may help to improve future asthma care. (C) 2011 Elsevier Ltd. All rights reserved.