Percutaneous central venous catheterization in premature infants: a method for facilitating insertion of silastic catheters via peripheral veins.

Peripheral venous cannulation is the preferred method of inserting central venous silastic catheters in premature infants. The standard techniques are placement of the catheter using a breakaway introducer needle or introduction of the catheter through a cannula. In extremely low birth weight infants (<1000 g) successful cannulation is impeded by the small size of the vessels. After repeated attempts, both procedures can be time-consuming and stressful to the infant. We present a modified insertion technique of the standard 2-French silastic catheter with an increased success rate, thus reducing insertion time, stress to the infant, and costs. The method uses the tip of a 20-gauge cannula as dilator/introducer for the 2-French catheter. This tip is inserted into the vessel with a standard 24-gauge cannula. After successful insertion of the dilator/introducer cannula, the standard 2-French catheter can then be advanced easily.

Evolution in subdivided plant populations: concepts, recent advances and future directions.

SUMMARY: Research into the evolution of subdivided plant populations has long involved the study of phenotypic variation across plant geographic ranges and the genetic details underlying that variation. Genetic polymorphism at different marker loci has also allowed us to infer the long- and short-term histories of gene flow within and among populations, including range expansions and colonization-extinction dynamics. However, the advent of affordable genome-wide sequences for large numbers of individuals is opening up new possibilities for the study of subdivided populations. In this review, we consider what the new tools and technologies may allow us to do. In particular, we encourage researchers to look beyond the description of variation and to use genomic tools to address new hypotheses, or old ones afresh. Because subdivided plant populations are complex structures, we caution researchers away from adopting simplistic interpretations of their data, and to consider the patterns they observe in terms of the population genetic processes that have given rise to them; here, the genealogical framework of the coalescent will continue to be conceptually and analytically useful.

Analyse de la Vulnérabilité des populations et proposition d’une méthodologie pour l’élaboration d’un PMACC: cas de la municipalité de São Domingos- Cap Vert

Le présent travail avait comme objectif principal l’intégration des stratégies d’adaptation au Changement Climatique dans le Plans Municipaux. Les principales activités économiques de S. Domingos sont l’agriculture, l’élevage et la pêche toutes fortement menacées par le changement climatique. Pour conduire cette étude, nous avons d’abord mené une enquête auprès des principaux auteurs de développement local, à savoir les agriculteurs, les éleveurs et les pêcheurs et, aux des services techniques dans la municipalité, puis dépouiller les informations recueillies. Le dépouillement a été assuré grâce aux logiciels SPSS et CRiSTAL. De l’analyse de la vulnérabilité des populations locales, nous avons conclut que la municipalité est très vulnérable aux effets néfastes du changement climatique. Il ressort une nécessité urgente d’y promouvoir l’adaptation au changement climatique. Un ensemble de mesures d’adaptation considérées prioritaires a été proposé, afin qu’elles soient intégrées dans le PDM, en vue d’une amélioration de la productivité des systèmes agro-sylvopastoraux et halieutiques, dans la municipalité de São Domingos. Le PMACC proposé, en tant qu’outil de planification et de gestion intégrée, naturellement, privilégie une approche intersectorielle et intégrée; il pourra donc apporter un «plus» dans les actions d’adaptation au changement climatique dans la région

Periphere okklusive Vaskulopathie bei einer Patientin mit kombinierter Präeklampsie und Alpha-Thalassämie minor [Peripheral occlusive retinal vasculopathy in a woman with combined preeclampsia and alpha thalassemia minor].

Normalerweise eine Störung der ersten Schwangerschaft, ist die Präeklampsie charakterisiert durch eine arterielle Hypertonie (> 140 mmHg systolisch oder > 90 mmHg diastolisch), die in der Regel nach der 20. Schwangerschaftswoche auftritt und von einer Proteinurie begleitet wird [1]. Die Präeklampsie wird als ,,schwer" bezeichnet, wenn sie mit einer wesentlichen Erhöhung des Blutdrucks (> 160 mmHg systolisch oder > 110 mmHg diastolisch), schwerer Proteinurie, Oligurie, Lungenödem, abdominalen Schmerzen, Leberfunktionsstörungen, Thrombozytopenie und visuellen oder zerebralen Symptomen einhergeht. Eine Eklampsie wiederum ist durch die Entwicklung von tonisch-klonischen Anfällen bei einer präeklamptischen Patientin charakterisiert. Bei der Alpha-Thalassämie tritt ein Defekt von 2 oder mehr der 4 Alpha-Globin-Gene auf. Von einer Alpha-Thalassämie minor spricht man, wenn 2 Alpha-Ketten-Gene deletiert sind. Sie tritt häufig bei Menschen aus Afrika, Südostasien, dem westindischen und mediterranen Raum auf. Die Alpha-Thalassämie minor verursacht eine milde bis moderate mikrozytäre Anämie. Wir berichten über eine Patientin mit peripherer okklusiver Vaskulopathie im Rahmen einer kombinierten Präeklampsie und Alpha-Thalassämie minor.

Evolution in heterogeneous populations: from migration models to fixation probabilities.

Although dispersal is recognized as a key issue in several fields of population biology (such as behavioral ecology, population genetics, metapopulation dynamics or evolutionary modeling), these disciplines focus on different aspects of the concept and often make different implicit assumptions regarding migration models. Using simulations, we investigate how such assumptions translate into effective gene flow and fixation probability of selected alleles. Assumptions regarding migration type (e.g. source-sink, resident pre-emption, or balanced dispersal) and patterns (e.g. stepping-stone versus island dispersal) have large impacts when demes differ in sizes or selective pressures. The effects of fragmentation, as well as the spatial localization of newly arising mutations, also strongly depend on migration type and patterns. Migration rate also matters: depending on the migration type, fixation probabilities at an intermediate migration rate may lie outside the range defined by the low- and high-migration limits when demes differ in sizes. Given the extreme sensitivity of fixation probability to characteristics of dispersal, we underline the importance of making explicit (and documenting empirically) the crucial ecological/ behavioral assumptions underlying migration models.

A genetic isolation gradient of populations of the Balearic green toad (Bufo balearicus) follows rising eastward fragmentation of the rural landscapes on the island of Menorca.

We present the first approach to the genetic diversity and structure of the Balearic toad (Bufo balearicus Boettger, 1880) for the island of Menorca. Forty-one individ- uals from 21 localities were analyzed for ten microsatellite loci. We used geo-refer- enced individual multilocus genotypes and a model-based clustering method for the inference of the number of populations and of the spatial location of genetic dis- continuities between those populations.¦Only six of the microsatellites analyzed were polymorphic. We revealed a northwest- ern area inhabited by a single population with several well-connected localities and another set of populations in the southeast that includes a few unconnected small units with genetically significant differences among them as well as with the individ- uals from the northwest of the island. The observed fragmentation may be explained by shifts from agricultural to tourism practices that have been taking place on the island of Menorca since the 1960s. The abandonment of rural activities in favor of urbanization and concomitant service areas has mostly affected the southeast of the island and is currently threatening the overall geographic connectivity between the different farming areas of the island that are inhabited by the Balearic toad.

Toxicological and ultrastructural analysis of the impact of pesticides used in temperate fruit crops on two populations of Chrysoperla externa (Neuroptera, Chrysopidae)

This study aimed to evaluate the effects of (g a.i. L-1) abamectin (0.02), carbaryl (1.73), sulphur (4.8), fenitrothion (0.75), methidathion (0.4), and trichlorfon (1.5) on the survival of larvae and pupae, on the oviposition of adults and hatching of eggs from treated Chrysoperla externa third-instar larvae from two different populations (Bento Gonçalves and Vacaria, Rio Grande do Sul State, Brazil). Morphological changes caused by abamectin to eggs laid by C. externa from Vacaria population were evaluated by mean of ultrastructural analysis. The pesticides were applied on glass plates. Distilled water was used as control. For the evaluation of larvae mortality, a fully randomized experimental design in a 2 x 7 (two populations x seven treatments) factorial scheme was used, whereas for the effects of the compounds on oviposition capacity and egg viability, a 2 x 4 factorial scheme was used. Carbaryl, fenitrothion, and methidathion caused 100% mortality of larvae. Abamectin reduced the hatching of eggs from treated third-instar larvae of both populations; however, this pesticide presented highest toxicity on insects from Vacaria. The ultrastructural analysis showed that abamectin caused malformations in micropyle and in chorion external surface of C. externa eggs. Based in the total effect (E), carbaryl, fenitrothion, and methidathion are harmful to C. externa; trichlorfon is harmless to third-instar larvae, while abamectin and sulphur are harmless and slightly harmful to third-instar larvae from Bento Gonçalves and Vacaria, respectively.

Historical contingency affects signaling strategies and competitive abilities in evolving populations of simulated robots.

One of the key innovations during the evolution of life on earth has been the emergence of efficient communication systems, yet little is known about the causes and consequences of the great diversity within and between species. By conducting experimental evolution in 20 independently evolving populations of cooperatively foraging simulated robots, we found that historical contingency in the occurrence order of novel phenotypic traits resulted in the emergence of two distinct communication strategies. The more complex foraging strategy was less efficient than the simpler strategy. However, when the 20 populations were placed in competition with each other, the populations with the more complex strategy outperformed the populations with the less complex strategy. These results demonstrate a tradeoff between communication efficiency and robustness and suggest that stochastic events have important effects on signal evolution and the outcome of competition between distinct populations.

Genetic structure of populations of Pissodes castaneus (De Geer) (Coleoptera, Curculionidae) using amplified fragment length polymorphism

Genetic structure of populations of Pissodes castaneus (De Geer) (Coleoptera, Curculionidae) using amplified fragment length polymorphism. The objective of this study was to determine the genetic structure of populations of Pissodes castaneus from different areas and on different species of Pinus using the PCR-AFLP technique. Twenty samples were analyzed, representing 19 populations from Brazil and one from Florence, Italy, which is the region of origin of P. castaneus. The four combinations of primers generated a total of 367 fragments of DNA, and 100% of polymorphic loci, indicating high degree of molecular polymorphism. The dendrogram did not reveal trends for grouping the populations in relation to origin. The low genetic similarity (0.11 between the most distant groups) and genetic distances of 0.13 and 0.44 for 10 out of the 20 samples may indicate several founding events or multiple introductions of heterogeneous strains into Brazil. The allelic fixation index (Fst) was 0.3851, considered high, and the number of migrants (Nm) was 0.3991, indicating low gene flow among populations. The highest genetic distances were between the population from Irani, SC and Cambará do Sul, RS and Bituruna, PR, indicating an independent founding event or a particular allelic fixation in the former location. The high genetic diversity among populations points out that the populations are genetically heterogeneous with a diverse gene pool in the surveyed areas, what makes them to respond differently to control measures.

Distinct genetic structure in populations of Chrysoperla externa (Hagen) (Neuroptera, Chrysopidae) shown by genetic markers ISSR and COI gene

Distinct genetic structure in populations of Chrysoperla externa (Hagen) (Neuroptera, Chrysopidae) shown by genetic markers ISSR and COI gene. Green lacewings are generalist predators, and the species Chrysoperla externa presents a great potential for use in biological control of agricultural pests due to its high predation and reproduction capacities, as well as its easy mass rearing in the laboratory. The adaptive success of a species is related to genetic variability, so that population genetic studies are extremely important in order to maximize success of the biological control. Thus, the present study used nuclear (Inter Simple Sequence Repeat - ISSR) and mitochondrial (Cytochrome Oxidase I - COI) molecular markers to estimate the genetic variability of 12 populations in the São Paulo State, Brazil, as well as the genetic relationships between populations. High levels of genetic diversity were observed for both markers, and the highest values of genetic diversity appear associated with municipalities that have the greatest areas of native vegetation. There was high haplotype sharing, and there was no correlation between the markers and the geographic distribution of the populations. The AMOVA indicated absence of genetic structure for the COI gene, suggesting that the sampled areas formed a single population unit. However, the great genetic differentiation among populations showed by ISSR demonstrates that these have been under differentiation after their expansion or may also reflect distinct dispersal behavior between males and females.

Fish populations surviving estrogen pollution.

Among the most common pollutants that enter the environment after passing municipal wastewater treatment are estrogens, especially the synthetic 17α-ethinylestradiol that is used in oral contraceptives. Estrogens are potent endocrine disruptors at concentrations frequently observed in surface waters. However, new genetic analyses suggest that some fish populations can be self-sustaining even in heavily polluted waters. We now need to understand the basis of this tolerance.

Substance P-like-immunoreactive sensory neurons in dorsal root ganglia of the chick embryo: ontogenesis and influence of peripheral targets.

The expression of substance P (SP) was studied in sensory neurons of developing chick lumbosacral dorsal root ganglia (DRG) by using a mixture of periodic acid, lysine and paraformaldehyde as fixative and a monoclonal antibody for SP-like immunostaining. The first SP-like-immunoreactive DRG cells appeared first at E5, then rapidly increased in number to reach a peak (88% of ganglion cells) at E8, and finally declined (59% at E12, 51% after hatching). The fall of the SP-like-positive DRG cells resulted from two concomitant events affecting a subset of small B-neurons: a loss of neuronal SP-like immunoreactivity and cell death. After one hindlimb resection at an early (E6) or late (E12) stage of development (that is before or after establishment of peripheral connections), the DRG were examined 6 days later. In both cases, a drastic neuronal death occurred in the ispilateral DRG. However, the resection at E6 did not change the percentage of SP-like-positive neurons, while the resection at E12 severely reduced the proportion of SP-like-immunoreactive DRG cells (25%). In conclusion, connections established between DRG and peripheral target tissues not only promote the survival of sensory neurons, but also control the maintenance of SP-like-expression. Factors issued from innervated targets such as NGF would support the survival of SP-expressing DRG cells and enhance their SP content while other factors present in skeletal muscle or skin would hinder SP expression and therefore lower SP levels in a subset of primary sensory neurons.

Contrasting patterns of insecticide resistance and knockdown resistance (kdr) in Aedes aegypti populations from Jacarezinho (Brazil) after a Dengue Outbreak

ABSTRACT After a dengue outbreak, the knowledge on the extent, distribution and mechanisms of insecticide resistance is essential for successful insecticide-based dengue control interventions. Therefore, we evaluated the potential changes to insecticide resistance in natural Aedes aegypti populations to Organophosphates (OP) and Pyrethroids (PY) after chemical vector control interventions. After a Dengue outbreak in 2010, A. aegypti mosquitoes from the urban area of Jacarezinho (Paraná, Brazil) were collected in 2011 and 2012. Insecticide resistance to OP Temephos was assessed in 2011 and 2012 by dose–response bioassays adopting WHO-based protocols. Additionally, in both sampling, PY resistance was also investigated by the Val1016Ile mutation genotyping. In 2011, a random collection of mosquitoes was carried out; while in 2012, the urban area was divided into four regions where mosquitoes were sampled randomly. Bioassays conducted with larvae in 2011 (82 ± 10%; RR95 = 3.6) and 2012 (95 ± 3%; RR95 = 2.5) indicated an incipient altered susceptibility to Temephos. On the other hand, the Val1016IIe mutation analysis in 2011, presented frequencies of the 1016Ilekdr allele equal to 80%. Nevertheless, in 2012, when the urban area of Jacarezinho was analyzed as a single unit, the frequency of the mutant allele was 70%. Additionally, the distribution analysis of the Val1016Ile mutation in 2012 showed the mutant allele frequencies ≥60% in all regions. These outcomes indicated the necessity of developing alternative strategies such as insecticide rotations for delaying the evolution of resistance.

Variability of a peripheral dose among various linac geometries for second cancer risk assessment.

Second cancer risk assessment for radiotherapy is controversial due to the large uncertainties of the dose-response relationship. This could be improved by a better assessment of the peripheral doses to healthy organs in future epidemiological studies. In this framework, we developed a simple Monte Carlo (MC) model of the Siemens Primus 6 MV linac for both open and wedged fields that we then validated with dose profiles measured in a water tank up to 30 cm from the central axis. The differences between the measured and calculated doses were comparable to other more complex MC models and never exceeded 50%. We then compared our simple MC model with the peripheral dose profiles of five different linacs with different collimation systems. We found that the peripheral dose between two linacs could differ up to a factor of 9 for small fields (5 × 5 cm(2)) and up to a factor of 10 for wedged fields. Considering that an uncertainty of 50% in dose estimation could be acceptable in the context of risk assessment, the MC model can be used as a generic model for large open fields (≥10 × 10 cm(2)) only. The uncertainties in peripheral doses should be considered in future epidemiological studies when designing the width of the dose bins to stratify the risk as a function of the dose.