Transition modes and institutional outcomes in El Salvador and Guatemala

Institutions affect key dimensions of the political process –policy, stability, and conflict. The choice of institutions is thus consequential. I argue that transition modes affect the choice of institutions in predictable and systematic ways. The more balanced power is between the two main bargaining forces –regime elite and opposition– the likelier that the resulting institutions will be pluralistic. Contrarily, the more unbalanced power is in favour of regime elites vis a vis the opposition, the likelier that institutions will be majoritarian. The argument is tested for El Salvador and Guatemala.

Capitalism, unemployment and the transition to the contemporary pattern of growth

A new model of unemployment based on an idea of Marx is presented and used to interpret the development of the British economy from the beginning of capitalism to the present. It is shown that unemployment may be created purposely by capitalists in order to weaken the bargaining position of the workers. This mechanism leads to complex temporal pattern of unemployment and can explain why wages took almost a century and a half to react to the growing capital to labour ratio that characterised early British capitalism.

Ten Propositions on Rural Poverty and Agrarian Transition in Central Eurasia

The relation between agricultural development and rural poverty reduction in six Central Eurasian countries, namely Azerbaijan (South Caucasus) and Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan (Central Asia), is discussed by presenting and analyzing ten propositions. These propositions cover a broad range of issues that relate to rural poverty in this region, such as: the state of income and non-income poverty; the diverse processes of land reform and farm restructuring, and agricultural policy reform; and finally, the institutional and market framework that is needed for dynamic agricultural and rural development. The paper contends that rural poverty is not responding as robustly to rapid economic growth in these countries, and that agricultural growth, in particular in the newly emerging peasant farm sector, is necessary to promote rural poverty reduction.

Mediterranean diet changes during the nutritional transition in Spain

En este trabajo analizaremos en primer lugar la presencia i la importancia de los alimentos que caracterizan la dieta mediterránea en los sistemas alimentarios españoles del siglo XIX. Veremos como evoluciona esta presencia y el su peso a la dieta dentro del proceso de transición nutricional moderna española, contemplando dos períodos: desde finales del XIX hasta la década de 1930, y la segunda mitad del XX, períodos caracterizados por un aumento de la ingesta de alimentos, cereales y patatas primer, y de productos de origen animal después, y por la progresiva convergencia con las dietes de les sociedades desarrolladas, que diluirían o minimizarían progresivamente las características diferenciales mediterráneos. Situaremos los cambios que se producen a España en el contexto europeo, i finalmente, analizaremos en que medida, en la etapa inicial, la dieta seguida se ajustaba a les necesidades de la población y a la dieta actualmente recomendada, y si se produjeron cambios significativos en el curso de la transición alimentaria.

Challenge of transition in the socio-professional insertion of youngsters with neurodisabilities

Patients with neurodisabilities require early management, continuing into adulthood. Thus, transition services were implemented in hospitals. To have a better support when they enter into adult life, it is useful to know the problems that they could face. The aim of this study is to evaluate their activities and to assess their insertion problems in the professional world. It is based on medical records of patients, aged 16 to 25 years, followed in the transition clinic of young adults in the Neurorehabilitation services of a tertiary centre. From 387 patients of the paediatric consultation, there are 267 patients (69%), included 224 with neurodevelopmental diseases and 43 with neuromuscular diseases. Nearly half of them (46.8%) were in a protected environment, 37.08% studied and 3.4% worked. Paradoxically, only 29.2% reported work problems. These results highlight the need to increase the integration of young adults with neuromotor disorders in the labor market.

The specificity of TRIM5 alpha-mediated restriction is influenced by its coiled-coil domain.

Retroviruses are both powerful evolutionary forces and dangerous threats to genome integrity. As such, they have imposed strong selective pressure on their hosts, notably triggering the emergence of restriction factors, such as TRIM5 alpha, that act as potent barriers to their cross-species transmission. TRIM5 alpha orthologues from different primates have distinct retroviral restriction patterns, largely dictated by the sequence of their C-terminal PRYSPRY domain, which binds the capsid protein of incoming virions. Here, by combining genetic and functional analyses of human and squirrel monkey TRIM5 alpha, we demonstrate that the coiled-coil domain of this protein, thus far essentially known for mediating oligomerization, also conditions the spectrum of antiretroviral activity. Furthermore, we identify three coiled-coil residues responsible for this effect, one of which has been under positive selection during primate evolution, notably in New World monkeys. These results indicate that the PRYSPRY and coiled-coil domains cooperate to determine the specificity of TRIM5 alpha-mediated capture of retroviral capsids, shedding new light on this complex event.

Solid-phase synthesis and NMR studies of modified oligonucleotides forming triplex helix and of oligonucleopeptides mimicking the topoisomerase I-DNA covalent complex

Report for the scientific sojourn carried out at the Institut de Biologia Molecular de Barcelona of the CSIC –state agency – from april until september 2007. Topoisomerase I is an essential nuclear enzyme that modulates the topological status of DNA, facilitating DNA helix unwinding during replication and transcription. We have prepared the oligonucleotide-peptide conjugate Ac-NLeu-Asn-Tyr(p-3’TTCAGAAGC5’)-LeuC-CONH-(CH2)6-OH as model compound for NMR studies of the Topoisomerase I- DNA complex. Special attention was made on the synthetic aspects for the preparation of this challenging compound especially solid supports and protecting groups. The desired peptide was obtained although we did not achieve the amount of the conjugate needed for NMR studies. Most probably the low yield is due to the intrinsic sensitive to hydrolysis of the phosphate bond between oligonucleotide and tyrosine. We have started the synthesis and the structural characterization of oligonucleotides carrying intercalating compounds. At the present state we have obtained model duplex and quadruplex sequences modified with acridine and NMR studies are underway. In addition to this project we have successfully resolved the structure of a fusion peptide derived from hepatitis C virus envelope synthesized by the group of Dr. Haro and we have synthesized and started the characterization of a modified G-quadruplex.

On the transition of genetic differentiation from isolation to panmixia: What we can learn from GST and D.

Population genetic differentiation characterizes the repartition of alleles among populations. It is commonly thought that genetic differentiation measures, such as GST and D, should be near zero when allele frequencies are close to their expected value in panmictic populations, and close to one when they are close to their expected value in isolated populations. To analyse those properties, we first derive analytically a reference function f of known parameters that describes how important features of genetic differentiation (e.g. gene diversity, proportion of private alleles, frequency of the most common allele) are close to their expected panmictic and isolation value. We find that the behaviour of function f differs according to three distinct mutation regimes defined by the scaled mutation rate and the number of populations. Then, we compare GST and D to f, and demonstrate that their signal of differentiation strongly depends on the mutation regime. In particular, we show that D captures well the variations of genetic diversity when mutation is weak, otherwise it overestimates it when panmixia is not met. GST detects population differentiation when mutation is intermediate but has a low sensitivity to the variations of genetic diversity when mutation is weak. When mutation is strong the domain of sensitivity of both measures are altered. Finally, we also point out the importance of the number of populations on genetic differentiation measures, and provide recommendations for the use of GST and D.

The twist, writhe and overall shape of supercoiled DNA change during counterion-induced transition from a loosely to a tightly interwound superhelix. Possible implications for DNA structure in vivo.

A cryo-electron microscopy study of supercoiled DNA molecules freely suspended in cryo-vitrified buffer was combined with Monte Carlo simulations and gel electrophoretic analysis to investigate the role of intersegmental electrostatic repulsion in determining the shape of supercoiled DNA molecules. It is demonstrated here that a decrease of DNA-DNA repulsion by increasing concentrations of counterions causes a higher fraction of the linking number deficit to be partitioned into writhe. When counterions reach concentrations likely to be present under in vivo conditions, naturally supercoiled plasmids adopt a tightly interwound conformation. In these tightly supercoiled DNA molecules the opposing segments of interwound superhelix seem to directly contact each other. This form of supercoiling, where two DNA helices interact laterally, may represent an important functional state of DNA. In the particular case of supercoiled minicircles (178 bp) the delta Lk = -2 topoisomers undergo a sharp structural transition from almost planar circles in low salt buffers to strongly writhed "figure-eight" conformations in buffers containing neutralizing concentrations of counterions. Possible implications of this observed structural transition in DNA are discussed.

The Child is father of the man: implications for the demographic transition

We propose a new theory of the demographic transition based on the evidence that body development during childhood is an important predictor of adult life expectancy. This theory is embodied in an OLG framework where fertility, longevity and education all result from individual decisions. The model displays different regimes, allowing the economy to move slowly from an initial Malthusian regime towards the Modern era. The dynamics reproduces the key features of the demographic transition, including the permanent increase in life expectancy, resulting from improvements in body development, the hump in both population growth and fertility, and a late increase in secondary educational attainments.

Syntaxin1a variants lacking an N-peptide or bearing the LE mutation bind to Munc18a in a closed conformation.

In neurons, soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) proteins drive the fusion of synaptic vesicles to the plasma membrane through the formation of a four-helix SNARE complex. Members of the Sec1/Munc18 protein family regulate membrane fusion through interactions with the syntaxin family of SNARE proteins. The neuronal protein Munc18a interacts with a closed conformation of the SNARE protein syntaxin1a (Syx1a) and with an assembled SNARE complex containing Syx1a in an open conformation. The N-peptide of Syx1a (amino acids 1-24) has been implicated in the transition of Munc18a-bound Syx1a to Munc18a-bound SNARE complex, but the underlying mechanism is not understood. Here we report the X-ray crystal structures of Munc18a bound to Syx1a with and without its native N-peptide (Syx1aΔN), along with small-angle X-ray scattering (SAXS) data for Munc18a bound to Syx1a, Syx1aΔN, and Syx1a L165A/E166A (LE), a mutation thought to render Syx1a in a constitutively open conformation. We show that all three complexes adopt the same global structure, in which Munc18a binds a closed conformation of Syx1a. We also identify a possible structural connection between the Syx1a N-peptide and SNARE domain that might be important for the transition of closed-to-open Syx1a in SNARE complex assembly. Although the role of the N-peptide in Munc18a-mediated SNARE complex assembly remains unclear, our results demonstrate that the N-peptide and LE mutation have no effect on the global conformation of the Munc18a-Syx1a complex.

Nutrition transition in a middle-income country: 22-year trends in the Seychelles.

BACKGROUND/OBJECTIVES: There is little objective information regarding nutrition transition in African countries. We assessed trends in nutrition patterns in the Seychelles between 1989 and 2011. SUBJECTS/METHODS: Population-based samples were obtained in 1989, 1994 and 2011 and participants aged 25-44 are considered in this study (n=493, 599 and 471, respectively). Similar, although not identical, food frequency questionnaires (FFQs) were used in each survey and the variables were collapsed into homogenous categories for the purpose of this study. RESULTS: Between 1989 and 2011, consumption frequency of fish (5+/week) decreased from 93 to 74%, whereas the following increased: meat (5+/week) 25 to 51%, fruits (1+/week) 48 to 94%, salty snacks (1+/week) 22 to 64% and sweet snacks (1+/week) 38 to 67% (P<0.001 for all). Consumption frequency decreased for home-brewed alcoholic drinks (1+/week) 16 to 1%, but increased for wine (1+/week) 5 to 33% (both P<0.001). Between 2004 and 2011, consumption frequency decreased for rice (2/day) 62 to 57% and tea (1+/day) 72 to 68%, increased for poultry (1+/week) 86 to 96% (all P<0.01), and did not change for vegetables (70.3 to 69.8%, P=0.65). CONCLUSIONS: Seychelles is experiencing nutrition transition characterized by a decreased consumption frequency of traditional staple foods (fish, polished rice), beverages (tea) and of inexpensive home brews, and increased consumption frequency of meat, poultry and snacks. Food patterns also became more varied along with a broader availability of products in the 22-year interval. The health impact of these changes should be further studied.

Mutagenesis and modelling of the alpha(1b)-adrenergic receptor highlight the role of the helix 3/helix 6 interface in receptor activation.

Computer simulations on a new model of the alpha1b-adrenergic receptor based on the crystal structure of rhodopsin have been combined with experimental mutagenesis to investigate the role of residues in the cytosolic half of helix 6 in receptor activation. Our results support the hypothesis that a salt bridge between the highly conserved arginine (R143(3.50)) of the E/DRY motif of helix 3 and a conserved glutamate (E289(6.30)) on helix 6 constrains the alpha1b-AR in the inactive state. In fact, mutations of E289(6.30) that weakened the R143(3.50)-E289(6.30) interaction constitutively activated the receptor. The functional effect of mutating other amino acids on helix 6 (F286(6.27), A292(6.33), L296(6.37), V299(6.40,) V300(6.41), and F303(6.44)) correlates with the extent of their interaction with helix 3 and in particular with R143(3.50) of the E/DRY sequence.