Genes, chromosomes and development

Procura-se mostrar, no presente artigo, que nenhuma teoria micromerista consegue explicar os fenômenos genéticos, por não ser possível conferir a partículas a independência funcional relacionada com o trabalho que devem exercer de maneira específica no organismo. O fato dos gens se encontrarem em tôdas as células do organismo em desenvolvimento, mostra que essas entidades desenvolvem distintas atividades em diferentes tecidos. Mas acontece, que nem a microscopia eletrônica, nem a bioquímica, consegue descobrir nos cormossômios algo que possa corresponder ao conceito de gen-conta-de rosário da genética clássica. Entretanto, o cromossômio considerado como um todo pode com vantagem substituir os gens no seu papel de determinar os caracteres do organismo. Admitindo-se que os cromossômios se determinam com as células de que fazem parte, uns para trabalhar nos esboços de asas, outros nos de olhos, patas ou outras estruturas, compreende-se fàcilmente, que, por intermédio de distintos membros do clone que se inicia com a primeira divisão do ovo, uma dada sorte de cromossômio, funcionando como um todo especializado, pode exercer as atividades específicas que lhe são atribuídas. E isso, de pleno acôrdo com a embriologia experimental.

Analysis and removal of code clones in software product lines

Magdeburg, Univ., Fak. für Informatik, Diss., 2013

Analysis and numerical investigation of dynamic models for liquid chromatography

Magdeburg, Univ., Fak. für Mathematik, Diss., 2013

On the structure and development of the vertebral column of Amia [by] O. P. Hay.

v.1:no.1(1895)

Morphology and development of the postcranial skeleton in the channel catfish Ictalurus punctatus (Ostariophysi: Siluriformes) / Terry Grande, Judith D. Shardo.

n.s. no.99(2002)

American medical botany :being a collection of the native medicinal plants of the United States, containing their botanical history and chemical analysis, and properties and uses in medicine, diet and the arts /by Jacob Bigelow.

v. 1

American medical botany :being a collection of the native medicinal plants of the United States, containing their botanical history and chemical analysis, and properties and uses in medicine, diet and the arts /by Jacob Bigelow.

v. 2

American medical botany :being a collection of the native medicinal plants of the United States, containing their botanical history and chemical analysis, and properties and uses in medicine, diet and the arts /by Jacob Bigelow.

v. 3

The study of insect blood-feeding behaviour: 1. Feeding equipment, physical and endogenous factors, dose effect analysis, and diet destination

Experimental techniques that we have found useful during our studies of insect blood-feeding behaviour are reviewed. Some of the principal findings resulting from these techniques are discussed. Where directly applicable, the work of others is included, but no complete review of the subject has been attempted.

The Cultural Olympiad: objectives, programme and development

Working paper analysing the Cultural Olympiad of Barcelona in 1992. This was published as a chapter of the book entitled "Olympic Games, media and cultural exchanges: the experience of the last four summer Olympic Games" and edited by M. Ladrón de Guevara and M. Bardají.

Contracting Institutions and Development

The quality of contracting institutions has been thought to be of second-order importance next to the impact that good property rights institutions can have on long-run growth. Using a large range of proxies for each type of institution, we find a robust negative link between the quality of contracting institutions and long-run growth when we condition on property rights and a number of additional macroeconomic variables. Although the result remains something of a puzzle, we present evidence which suggests that only when property rights institutions are good do contracting institutions appear also to be good for development. Good contracting institutions can reduce long-run growth when property rights are not secured, presumably because the gains from the (costly) contracting institutions cannot be realised. This suggests that contracting institutions can benefit growth, and that the sequence of institutional change can matter.

The Argentine ant (Linepithema humile) invasion effects on Mediterranean forests’ trophic web: blue tit (Parus caeruleus) reproduction and development

Les invasions biològiques representen una greu amenaça per al funcionament dels ecosistemes i per a la preservació de la biodiversitat.. La formiga argentina (Linepithema humile) està considerada com una de les 100 espècies invasores més nocives. Prospera en extenses àrees de clima mediterrani de regions temperades i subtropicals de tots els continents amb l’excepció de l’Antàrtida. És una formiga dominant i una competidora agressiva que mitjançant múltiples mecanismes, des de predació directe a competència, produeix efectes negatius en una amplia varietat de taxons, principalment formigues i altres artròpodes, però també vertebrats. S’ha investigat, per primera vegada, els efectes de la formiga invasiva sobre les comunitats d’artròpodes de fullatge i com aquestes pertorbacions es transmeten en la xarxa tròfica del bosc esclerofil•le mediterrani. En les suredes estudiades la invasió de formiga argentina és causa directe de la extinció local de la gran majoria de poblacions de formigues natives. En el període mostrejat s’han constatat també impactes negatius en la diversitat i en l’abundància d’artròpodes natius en les capçades dels arbres, particularment d’erugues. Una avaluació preliminar basada únicament amb dades del 2005 indica que, reduint la disponibilitat d’erugues, la formiga argentina empobreix l’hàbitat reproductiu de la mallerenga blava (Parus caeruleus). La mallerenga blava basa la dieta insectívora estricte de la seva pollada fonamentalment en les erugues. No hem detectat impactes en l’èxit reproductiu de les mallerengues blaves en zones envaïdes. Els polls crescuts en àrees envaïdes assoleixen una condició física similar als de les zones no envaïdes, però la reducció en la disponibilitat d’erugues associada a la invasió de formiga argentina es tradueix en un creixement descompassat i en una menor mida estructural del polls volanders. Així, les pertorbacions en la comunitat d’artròpodes associades a la invasió de la formiga argentina promouen efectes bottom-up que acaben perjudicant el desenvolupament dels polls de mallerenga blava.

Molecular karyotype analysis and mapping of housekeeping genes to chromosomes of selected species complexes of Leishmania

The molecular karyotypes for 20 reference strais of species complexes of Leishmania were determined by contour-clamped homogeneous eletric field (CHEF) electrosphoresis. Determination of number/position of chromosome-sized bands and chromosomal DNA locations of house-keeping genes were the two criteria used for differentiating and classifying the Leishmania species. We have established two gel running conditions of optimal separation of chromosomes, wich resolved DNA molecules as large as 2,500 kilobase pairs (kb). Chromosomes were polymorphic in number (22-30) and size (200-2,500 kb) of bands among members of five complexes of Leishmania. Although each stock had a distinct karyotype, in general the differences found between strains and/or species within each complex were not clear enough for parasite identification. However, each group showed a specific number of size-concordant DNA molecules, wich allowed distinction among the Leishmania complex parasites. Clear differences between the Old and New world groups of parasites or among some New World Leishmania species were also apparent in relation to the chromosome locations of beta-tubulin genes. Based on these results as well as data from other published studies the potencial of using DNA karyotype for identifying and classifying leishmanial field isolates is discussed.

Transitions in social complexity along elevational gradients reveal a combined impact of season length and development time on social evolution.

Eusociality is taxonomically rare, yet associated with great ecological success. Surprisingly, studies of environmental conditions favouring eusociality are often contradictory. Harsh conditions associated with increasing altitude and latitude seem to favour increased sociality in bumblebees and ants, but the reverse pattern is found in halictid bees and polistine wasps. Here, we compare the life histories and distributions of populations of 176 species of Hymenoptera from the Swiss Alps. We show that differences in altitudinal distributions and development times among social forms can explain these contrasting patterns: highly social taxa develop more quickly than intermediate social taxa, and are thus able to complete the reproductive cycle in shorter seasons at higher elevations. This dual impact of altitude and development time on sociality illustrates that ecological constraints can elicit dynamic shifts in behaviour, and helps explain the complex distribution of sociality across ecological gradients.