Evolution at Two Levels in Fire Ants: The Relationship between Patterns of Gene Expression and Protein Sequence Evolution.

Variation in protein sequence and gene expression each contribute to phenotypic diversity, and may be subject to similar selective pressures. Eusocial insects are particularly useful for investigating the evolutionary link between protein sequence and condition-dependent patterns of gene expression because gene expression plays a central role in determining differences between eusocial insect sexes and castes. We investigated the relationship between protein coding sequence evolution and gene expression patterns in the fire ants Solenopsis invicta, S. richteri, and their hybrids to gain greater insight into how selection jointly operates on gene expression and coding sequence. We found that genes with high expression variability within castes and sexes were frequently differentially expressed between castes and sexes, as well as between species and hybrids. These results indicate that genes showing high variation in expression in one context also tend to show high variation in expression in other contexts. Our analyses further revealed that variation in both intra- and interspecific gene expression was positively associated with rate of protein sequence evolution in Solenopsis. This suggests that selective constraints on a gene operate both at the level of protein sequence and at the level of gene expression regulation. Overall, our study provides one of the strongest demonstrations that selective constraints mediate both protein sequence evolution and gene expression variability across different biological contexts and timescales.

Simple method for detection of MYH11 DNA rearrangements in patients with inv(16)(p13q22) and acute myeloid leukemia.

The pericentric inversion on chromosome 16 [inv(16)(p13q22)] and related t(16;16)(p13;q22) are recurrent aberrations associated with acute myeloid leukemia (AML) M4 Eo. Both abberations result in a fusion of the core binding factor beta (CBFB) and smooth muscle myosin heavy chain gene (MYH11). A selected genomic 6.9-kb BamHl probe detects MYH11 DNA rearrangements in 18 of 19 inv(16)/t(16;16) patients tested using HindIII digested DNA. The rearranged fragments were not detectable after remission in two cases tested, while they were present after relapse in one of these two cases tested.

World population growth and fertility patterns, 1960-2000. A simple model explaining the evolution of world's fertility during the second half of the 20th Century

In this paper we attempt to describe the general reasons behind the world populationexplosion in the 20th century. The size of the population at the end of the century inquestion, deemed excessive by some, was a consequence of a dramatic improvementin life expectancies, attributable, in turn, to scientific innovation, the circulation ofinformation and economic growth. Nevertheless, fertility is a variable that plays acrucial role in differences in demographic growth. We identify infant mortality, femaleeducation levels and racial identity as important exogenous variables affecting fertility.It is estimated that in poor countries one additional year of primary schooling forwomen leads to 0.614 child less per couple on average (worldwide). While it may bepossible to identify a global tendency towards convergence in demographic trends,particular attention should be paid to the case of Africa, not only due to its differentdemographic patterns, but also because much of the continent's population has yet toexperience improvement in quality of life generally enjoyed across the rest of theplanet.

Social preferences: Some simple tests and a new model

Departures from pure self interest in economic experiments have recently inspired models of "social preferences". We conduct experiments on simple two-person and three-person games with binary choices that test these theories more directly than the array of games conventionally considered. Our experiments show strong support for the prevalence of "quasi-maximin" preferences: People sacrifice to increase the payoffs for all recipients, but especially for the lowest-payoff recipients. People are also motivated by reciprocity: While people are reluctant to sacrifice to reciprocate good or bad behavior beyond what they would sacrifice for neutral parties, they withdraw willingness to sacrifice to achieve a fair outcome when others are themselves unwilling to sacrifice. Some participants are averse to getting different payoffs than others, but based on our experiments and reinterpretation of previous experiments we argue that behavior that has been presented as "difference aversion" in recent papers is actually a combination of reciprocal and quasi-maximin motivations. We formulate a model in which each player is willing to sacrifice to allocate the quasi-maximin allocation only to those players also believed to be pursuing the quasi-maximin allocation, and may sacrifice to punish unfair players.

Exact tests for correlation and for the slope in simple linear regressions without making assumptions

We present an exact test for whether two random variables that have known bounds on their support are negatively correlated. The alternative hypothesis is that they are not negatively correlated. No assumptions are made on the underlying distributions. We show by example that the Spearman rank correlation test as the competing exact test of correlation in nonparametric settings rests on an additional assumption on the data generating process without which it is not valid as a test for correlation.We then show how to test for the significance of the slope in a linear regression analysis that invovles a single independent variable and where outcomes of the dependent variable belong to a known bounded set.

A simple access pricing rule to achieve the Ramsey outcome for interconnected networks

This paper considers a general and informationally efficient approach to determine the optimal access pricing rule for interconnected networks. It shows that there exists a simple rule that achieves the Ramsey outcome as the unique equilibrium when networks compete in linear prices without network-based price discrimination. The approach is informationally efficient in the sense that the regulator is required to know only the marginal cost structure, i.e. the marginal cost of making and terminating a call. The approach is general in that access prices can depend not only on the marginal costs but also on the retail prices, which can be observed by consumers and therefore by the regulator as well. In particular, I consider the set of linear access pricing rules which includes any fixed access price, the Efficient Component Pricing Rule (ECPR) and the Modified ECPR as special cases. I show that in this set, there is a unique rule that implements the Ramsey outcome as the unique equilibrium independently of the underlying demand conditions.

Nonlinear models and small sample performance of the generalized method of moments

In this paper I explore the issue of nonlinearity (both in the datageneration process and in the functional form that establishes therelationship between the parameters and the data) regarding the poorperformance of the Generalized Method of Moments (GMM) in small samples.To this purpose I build a sequence of models starting with a simple linearmodel and enlarging it progressively until I approximate a standard (nonlinear)neoclassical growth model. I then use simulation techniques to find the smallsample distribution of the GMM estimators in each of the models.

Flexible social organization and high incidence of drifting in the sweat bee, Halictus scabiosae.

The very diverse social systems of sweat bees make them interesting models to study social evolution. Here we focus on the dispersal behaviour and social organization of Halictus scabiosae, a common yet poorly known species of Europe. By combining field observations and genetic data, we show that females have multiple reproductive strategies, which generates a large diversity in the social structure of nests. A detailed microsatellite analysis of 60 nests revealed that 55% of the nests contained the offspring of a single female, whereas the rest had more complex social structures, with three clear cases of multiple females reproducing in the same nest and frequent occurrence of unrelated individuals. Drifting among nests was surprisingly common, as 16% of the 122 nests in the overall sample and 44% of the nests with complex social structure contained females that had genotypes consistent with being full-sisters of females sampled in other nests of the population. Drifters originated from nests with an above-average productivity and were unrelated to their nestmates, suggesting that drifting might be a strategy to avoid competition among related females. The sex-specific comparison of genetic differentiation indicated that dispersal was male-biased, which would reinforce local resource competition among females. The pattern of genetic differentiation among populations was consistent with a dynamic process of patch colonization and extinction, as expected from the unstable, anthropogenic habitat of this species. Overall, our data show that H. scabiosae varies greatly in dispersal behaviour and social organization. The surprisingly high frequency of drifters echoes recent findings in wasps and bees, calling for further investigation of the adaptive basis of drifting in the social insects.

Geometry, petrology and growth of a shallow crustal laccolith : the Torres del Paine Mafic Complex (Patagonia)

1. ABSTRACTS - RÉSUMÉSSCIENTIFIC ABSTRACT - ENGLISH VERSIONGeometry, petrology and growth of a shallow crustal laccolith: the Torres del Paine Mafi c Complex (Patagonia)The Torres del Paine intrusive complex (TPIC) is a composite mafic-granitic intrusion, ~70km2, belonging to a chain of isolated Miocene plutons in southern Patagonia. Their position is intermediate between the Mesozoic-Cenozoic calc-alkaline subduction related Patagonian batholith in the West and the late Cenozoic alkaline basaltic back-arc related plateau lavas in the East. The Torres del Paine complex formed during an important reconfiguration of the Patagonian geodynamic setting, with a migration of magmatism from the arc to the back-arc, possibly related to the Chile ridge subductionThe complex intruded the flysch of the Cretaceous Cerro Toro and Punta Barrosa Formations during the Miocene, creating a well-defined narrow contact aureole of 200-400 m width.In its eastern part, the Torres del Paine intrusive complex is a laccolith, composed of a succession of hornblende-gabbro to diorite sills at its base, with a total thickness of ~250m, showing brittle contacts with the overlying granitic sills, that form spectacular cliffs of more than 1000m. This laccolith is connected, in the western part, to its feeding system, with vertical alternating sheets of layered gabbronorite and Hbl-gabbro, surrounded and percolated by diorites. ID-TIMS U-Pb on zircons on feeder zone (FZ) gab- bros yield 12.593±0.009Ma and 12.587±0.009Ma, which is identifcal within error to the oldest granite dated so far by Michel et al. (2008). In contrast, the laccolith mafic complex is younger than than the youngest granite (12.50±0.02Ma), and has been emplaced from 12.472±0.009Ma to 12.431 ±0.006Ma, by under-accretion beneath the youngest granite at the interface with previously emplaced mafic sills.The gabbronorite crystallization sequence in the feeder zone is dominated by olivine, plagioclase, clinopyroxene and orthopyroxene, while amphibole forms late interstitial crystals. The crystallization sequence is identical in Hornblende-gabbro from the feeder zone, with higher modal hornblende. Gabbronorite and Hornblende-gabbro both display distinct Eu and Sr positive anomalies. In the laccolith, a lower Hornblende-gabbro crystallized in sills and evolved to a high alkali shoshonitic series. The Al203, Ti02, Na20, K20, Ba and Sr composition of these gabbros is highly variable and increases up to ~50wt% Si02. The lower hornblende-gabbro is characterized by kaersutite anhedral cores with inclusions of olivine, clino- and orthopyroxene and rare apatite and An70 plagioclase. Trace element modelling indicates that hornblende and clinopyroxene are in equilibrium with a liquid whose composition is similar to late basaltic trachyandesitic dikes that cut the complex. The matrix in the lower hornblende gabbro is composed of normally zoned oligoclase, Magnesio-hornblende, biotite, ilmenite and rare quartz and potassium feldspar. This assemblage crystallized in-situ from a Ba and Sr-depleted melts. In contrast, the upper Hbl-gabbro is high-K calc-alkaline. Poikilitic pargasite cores have inclusions of euhedral An70 plagioclase inclusions, and contain occasionally clinopyroxene, olivine and orthopyroxene. The matrix composition is identical to the lower hornblende-gabbro and similar to the diorite. Diorite bulk rock compositions show the same mineralogy but different modal proportions relative to hornblende-gabbrosThe Torres del Paine Intrusive Complex isotopic composition is 87Sr/86Sr=0.704, 143Nd/144Nd=0.5127, 206Pb/204Pb=18.70 and 207Pb/204Pb=15.65. Differentiated dioritic and granitic units may be linked to the gabbroic cumulates series, with 20-50% trapped interstitial melt, through fractionation of olivine-bearing gabbronorite or hornblende-gabbro fractionation The relative homogeneity of the isotopic compositions indicate that only small amounts of assimilation occurred. Two-pyroxenes thermometry, clinopyroxene barometry and amphibole-plagioclase thermometry was used to estimate pressure and temperature conditions. The early fractionation of ultramafic cumulates occurs at mid to lower crustal conditions, at temperatures exceeding 900°C. In contrast, the TPIC emplacement conditions have been estimated to ~0.7±0.5kbar and 790±60°C.Based on field and microtextural observations and geochemical modelling, fractionation of basaltic-trachyandesitic liquids at intermediate to lower crustal levels, has led to the formation of the Torres del Paine granites. Repetitive replenishment of basaltic trachy- andesitic liquid in crustal reservoirs led to mixed magmas that will ascend via the feeder zone, and crystallize into a laccolith, in the form of successive dioritic and gabbroic sills. Dynamic fractionation during emplacement concentrated hornblende rich cumulates in the center of individual sills. Variable degrees.of post-emplacement compaction led to the expulsion of felsic liquids that preferentially concentrated at the top of the sills. Incremental sills amalgamation of the entire Torres del Paine Intrusive Complex has lasted for ~160ka.RESUME SCIENTIFIQUE - VERSION FRANÇAISEGéométrie, pétrologie et croissance d'un laccolite peu profond : Le complexe ma- fique du Torres del Paine (Patagonie)Le Complexe Intrusif du Torres del Paine (CITP) est une intrusion bimodale, d'environ 70km2, appartenant à une chaîne de plutons Miocènes isolés, dans le sud de la Patago-nie. Leur position est intermédiaire entre le batholite patagonien calco-alcalin, à l'Ouest, mis en place au Mesozoïque-Cenozoïque dans un contexte de subduction, et les basal-tes andésitiques et trachybasaltes alcalins de plateau, plus jeune, à l'Est, lié à l'ouverture d'un arrière-arc.A son extrémité Est, le CITP est une succession de sills de gabbro à Hbl et de diorite, sur une épaisseur de ~250m, avec des évidences de mélange. Les contacts avec les sills de granite au-dessus, formant des parois de plus de 1000m, sont cassants. Ce laccolite est connecté, dans sa partie Ouest, à une zone d'alimentation, avec des intrusions sub-ver- ticales de gabbronorite litée et de gabbro à Hbl, en alternance. Celles-ci sont traversées et entourées par des diorites. Les zircons des gabbros de la zone d'alimentation, datés par ID-TIMS, ont cristallisés à 12.593±0.009Ma et 12.587±0.009Ma, ce qui correspond au plus vieux granite daté à ce jour par Michel et al. (2008). A l'inverse, les roches manques du laccolite se sont mises en place entre 12.472±0.009Ma et 12.431 ±0.006Ma, par sous-plaquage successifs à l'interface avec le granite le plus jeune daté à ce jour (12.50±0.02Ma).La séquence de cristallisation des gabbronorites est dominée par Ol, Plg, Cpx et Opx, alors que la Hbl est un cristal interstitiel. Elle est identique dans les gabbros à Hbl de la zone d'alimentation, avec ~30%vol de Hbl. Les gabbros de la zone d'alimentation montrent des anomalies positives en Eu et Sr distinctes. Dans le laccolite, le gabbro à Hbl inférieur évolue le long d'une série shoshonitique, riche en éléments incompatibles. Sa concentration en Al203, Ti02, Na20, K20, Ba et Sr est très variable et augmente rapide-ment jusqu'à ~50wt% Si02. Il est caractérisé par la présence de coeurs résorbés de kaer- sutite, entourés de Bt, et contenant des inclusions d'OI, Cpx et Opx, ou alors d'Ap et de rares Plg (An70). Hbl et Cpx ont cristallisés à partir d'un liquide de composition similaire aux dykes trachy-andesite basaltique du CITP. La matrice, cristallisée in-situ à partir d'un liquide pauvre en Ba et Sr, est composée d'oligoclase zoné de façon simple, de Mg-Hbl, Bt, llm ainsi que de rares Qtz et KF. Le gabbro à Hbl supérieur, quant à lui, appartient à une suite chimique calco-alcaline riche en K. Des coeurs poecilitiques de pargasite con-tiennent de nombreuses inclusions de Plg (An70) automorphe, ainsi que des Ol, Cpx et Opx. La composition de la matrice est identique à celle des gabbros à Hbl inférieurs et toutes deux sont similaires à la minéralogie des diorites. Les analyses sur roches totales de diorites montrent la même variabilité que celles de gabbros à Hbl, mais avec une ten-eur en Si02 plus élevée.La composition isotopique des liquides primitifs du CITP a été mesurée à 87Sr/86Sr=0.704, 143Nd/144Nd=0.5127, 206Pb/204Pb=18.70 et 207Pb/204Pb=15.65. Les granites et diorites différenciés peuvent être reliés à des cumulais gabbronoritiques (F=0.74 pour les granites et F=1-0.5 pour les diorites) et gabbroïques à Hbl (fractionnement supplémentaire pour les granites, avec F=0.3). La cristallisation de 20 à 50%vol de liquide interstitiel piégé dans les gabbros du CITP explique leur signature géochimique. Seules de faibles quantités de croûte continentale ont été assimilées. La température et la pression de fractionnement ont été estimées, sur la base des thermobaromètres Opx-Cpx, Hbl-Plg et Cpx, à plus de 900°C et une profondeur correspondant à la croûte inférieure-moyenne. A l'inverse, les conditions de cristallisation de la matrice des gabbros et diorites du laccolite ont été estimées à 790±60°C et ~0.7±0.5kbar.Je propose que les liquides felsiques du CITP se soient formés par cristallisation frac-tionnée en profondeur des assemblages minéralogiques observés dans les gabbros du CITP, à partir d'un liquide trachy-andesite basaltique. La percolation de magma dans les cristaux accumulés permet la remontée du mélange à travers la zone d'alimentation, vers le laccolite, où des sills se mettent en place successivement. L'amalgamation de sills dans le CITP a duré ~160ka.Le CITP s'est formé durant une reconfiguration importante du contexte géodynamique en Patagonie, avec un changement du magmatisme d'arc vers un volcanisme d'arrière- arc. Ce changement est certainement lié à la subduction de la ride du Chili.RESUME GRAND PUBLIC - VERSION FRANÇAISEGéométrie, pétrologie et croissance d'une chambre magmatique peu profonde : Le complexe mafique du Torres del Paine (Patagonie)Le pourtour de l'Océan Pacifique est caractérisé par une zone de convergence de plaques tectoniques, appelée zone de subduction, avec le plongement de croûte océa-nique sous les Andes dans le cas de la Patagonie. De nombreux volcans y sont associés, formant la ceinture de feu. Mais seuls quelques pourcents de tout le magma traversant la croûte terrestre parviennent à la surface et la majeure partie cristallise en profondeur, dans des chambres magmatiques. Quelles est leur forme, croissance, cristallisation et durée de vie ? Le complexe magmatique du Torres del Paine représente l'un des meilleurs endroits au monde pour répondre à ces questions. Il se situe au sud de la Patagonie, formant un massif de 70km2. Des réponses peuvent être trouvées à différentes échelles, variant de la montagne à des minéraux de quelques 1000ème de millimètres.Il est possible de distinguer trois types de roches : des gabbros et des diorites sur une épaisseur de 250m, surmontées par des parois de granite de plus de 1000m. Les contacts entre ces roches sont tous horizontaux. Entre granites et gabbro-diorite, le contact est net, indiquant que le second magma s'est mis en place au contact avec un magma plus ancien, totalement solidifié. Entre gabbros et diorites, les contacts sont diffus, souvent non-linéaires, indiquant à l'inverse la mise en contact de magmas encore partiellement liquides. Dans la partie Ouest de cette chambre magmatique, les contacts entre roches sont verticaux. Il s'agit certainement du lieu de remplissage de la chambre magmatique.Lors du refroidissement d'un magma, différents cristaux vont se former. Leur stabilité et leur composition varient en fonction de la pression, de la température ou de la chimie du magma. La séquence de cristallisation peut être définie sur la base d'observations microscopiques et de la composition chimique des minéraux. Différents gabbros sont ainsi distingués : le gabbro à la base est riche en hornblende, d'une taille de ~5mm, sans inclusion de plagioclase mais avec des cristaux d'olivine, clinopyroxene et orthopyroxene inclus ; le gabbro supérieur est lui-aussi riche en hornblende (~5mm), avec les mêmes inclusions additionnées de plagioclase. Ces cristaux se sont formés à une température supérieure à 900°C et une profondeur correspondant à la croûte moyenne ou inférieure. Les minéraux plus fin, se trouvant hors des cristaux de hornblende des deux gabbros, sont similaires à ceux des diorites : plagioclase, biotite, hornblende, apatite, quartz et feldspath alcalin. Ces minéraux sont caractéristiques des granites. Ils ont cristallisé à ~790°C et ~2km de profondeur.La cristallisation des minéraux et leur extraction du magma par gravité provoque un changement progressif de la composition de ce dernier. Ainsi, après extraction d'olivine et d'orthopyroxene riches en Mg, de clinopyroxene riche en Ca, de plagioclase riche en Ca et Al et d'hornblende riche en Ca, Al et Mg, le liquide final sera appauvri en ces élé-ments. Un lien peut ainsi être proposé entre les diorites dont la composition est proche du liquide de départ, les granites dont la composition est similaire au liquide final, et les gabbros dont la minéralogie correspond aux minéraux extraits.L'utilisation de zircons, un minéral riche en U dont les atomes se transforment en Pb par décomposition radioactive au cours de millions d'années, permet de dater le refroidissement des roches qui les contiennent. Ainsi, il a été observé que les roches de la zone d'alimentation, à l'Ouest du complexe magmatique, ont cristallisés il y a 12.59±0.01 Ma, en même temps que les granites les plus vieux, se trouvant au sommet de la chambre magmatique, datés par Michel et al. (2008). Les deux roches pourraient donc avoir la même origine. A l'inverse, les gabbros et diorites de la chambre magmatique ont cristallisé entre 12.47±0.01Ma et 12.43±0.01Ma, les roches les plus vieilles étant à la base.En comparant la composition des roches du Torres del Paine avec celles d'autres en-tités géologiques de Patagonie, les causes du magmatisme peuvent être recherchées. A l'Ouest, on trouve en effet des intrusions granitiques, plus anciennes, caractéristiques de zones de convergence de plaque tectonique, alors qu'à l'Est, des laves basaltiques plus jeunes sont caractéristiques d'une dynamique d'extension. Sur la base des compositions chimiques des roches de ces différentes entités, l'évolution progressive de l'une à l'autre a pu être démontrée. Elle est certainement due à l'arrivée d'une dorsale océanique (zone d'extension crustale et de création de croûte océanique par la remontée de magma) dans la zone de subduction, le long des Andes.Je propose que, dans un premier temps, des magmas granitiques sont remontés dans la chambre magmatique, laissant d'importants volumes de cristaux dans la croûte pro-fonde. Dans un second épisode, les cristaux formés en profondeur ont été transportés à travers la croûte continentale, suite au mélange avec un nouveau magma injecté. Ces magmas chargés de cristaux ont traversé la zone d'alimentation avant de s'injecter dans la chambre magmatique. Différents puises ont été distingués, injectés dans la chambre magmatique du sommet à la base concernant les granites, puis à la base du granite le plus jeune pour les gabbros et diorites. Le complexe magmatique du Torres del Paine s'est construit sur une période totale de 160'000±20'000 ans.

Skin fibroblast model to study an impaired glutathione synthesis: consequences of a genetic polymorphism on the proteome.

An impaired glutathione (GSH) synthesis was observed in several multifactorial diseases, including schizophrenia and myocardial infarction. Genetic studies revealed an association between schizophrenia and a GAG trinucleotide repeat (TNR) polymorphism in the catalytic subunit (GCLC) of the glutamate cysteine ligase (GCL). Disease-associated genotypes of this polymorphism correlated with a decrease in GCLC protein expression, GCL activity and GSH content. To clarify consequences of a decreased GCL activity at the proteome level, three schizophrenia patients and three controls have been selected based on the GCLC GAG TNR polymorphism. Fibroblast cultures were obtained by skin biopsy and were challenged with tert-butylhydroquinone (t-BHQ), a substance known to induce oxidative stress. Proteome changes were analyzed by two dimensional gel electrophoresis (2-DE) and results revealed 10 spots that were upregulated in patients following t-BHQ treatment, but not in controls. Nine corresponding proteins could be identified by MALDI mass spectrometry and these proteins are involved in various cellular functions, including energy metabolism, oxidative stress response, and cytoskeletal reorganization. In conclusion, skin fibroblasts of subjects with an impaired GSH synthesis showed an altered proteome reaction in response to oxidative stress. Furthermore, the study corroborates the use of fibroblasts as an additional mean to study vulnerability factors of psychiatric diseases.

A simple model of multiple equilibria based on risk

This paper shows how risk may aggravate fluctuations in economies with imperfect insurance and multiple assets. A two period job matching model is studied, in which risk averse agents act both as workers and as entrepreneurs. They choose between two types of investment: one type is riskless, while the other is a risky activity that creates jobs.Equilibrium is unique under full insurance. If investment is fully insured but unemployment risk is uninsured, then precautionary saving behavior dampens output fluctuations. However, if both investment and employment are uninsured, then an increase in unemployment gives agents an incentive to shift investment away from the risky asset, further increasing unemployment. This positive feedback may lead to multiple Pareto ranked equilibria. An overlapping generations version of the model may exhibit poverty traps or persistent multiplicity. Greater insurance is doubly beneficial in this context since it can both prevent multiplicity and promote risky investment.

Cloning of a cDNA encoding a plasma membrane-associated, uronide binding phosphoprotein with physical properties similar to viral movement proteins.

Oligogalacturonides are structural and regulatory homopolymers from the extracellular pectic matrix of plants. In vitro micromolar concentrations of oligogalacturonates and polygalacturonates were shown previously to stimulate the phosphorylation of a small plasma membrane-associated protein in potato. Immunologically cross-reactive proteins were detected in plasma membrane-enriched fractions from all angiosperm subclasses in the Cronquist system. Polygalacturonate-enhanced phosphorylation of the protein was observed in four of the six dicotyledon subclasses but not in any of the five monocotyledon subclasses. A cDNA for the protein was cloned from potato. The deduced protein is extremely hydrophilic and has a proline-rich N terminus. The C-terminal half of the protein was predicted to be a coiled coil, suggesting that the protein interacts with other macromolecules. The recombinant protein was found to bind both simple and complex galacturonides. The behavior of the protein suggests several parallels with viral proteins involved in intercellular communication.

iLOGP: A Simple, Robust, and Efficient Description of n-Octanol/Water Partition Coefficient for Drug Design Using the GB/SA Approach.

The n-octanol/water partition coefficient (log Po/w) is a key physicochemical parameter for drug discovery, design, and development. Here, we present a physics-based approach that shows a strong linear correlation between the computed solvation free energy in implicit solvents and the experimental log Po/w on a cleansed data set of more than 17,500 molecules. After internal validation by five-fold cross-validation and data randomization, the predictive power of the most interesting multiple linear model, based on two GB/SA parameters solely, was tested on two different external sets of molecules. On the Martel druglike test set, the predictive power of the best model (N = 706, r = 0.64, MAE = 1.18, and RMSE = 1.40) is similar to six well-established empirical methods. On the 17-drug test set, our model outperformed all compared empirical methodologies (N = 17, r = 0.94, MAE = 0.38, and RMSE = 0.52). The physical basis of our original GB/SA approach together with its predictive capacity, computational efficiency (1 to 2 s per molecule), and tridimensional molecular graphics capability lay the foundations for a promising predictor, the implicit log P method (iLOGP), to complement the portfolio of drug design tools developed and provided by the SIB Swiss Institute of Bioinformatics.

A simple optimised search heuristic for the job-shop scheduling problem

This paper presents a simple Optimised Search Heuristic for the Job Shop Scheduling problem that combines a GRASP heuristic with a branch-and-bound algorithm. The proposed method is compared with similar approaches and leads to better results in terms of solution quality and computing times.