Analysis of the DNA adducts of phenyl glycidyl ether in a calf thymus DNA hydrolysate by capillary zone electrophoresis-electrospray mass spectrometry: evidence for phosphate alkylation

Calf thymus DNA was reacted irt vitro with phenyl glycidyl ether (PGE) and was hydrolysed enzymatically, to the 5'-monophosphate nucleotides using deoxyribonuclease I (DNA-ase I) and nuclease P1, The adducts were concentrated using solid phase extraction (SPE), on a polystyrene divinylbenzene copolymer in order to remove the unmodified nucleotides. The adducts could be identified using capillary zone electrophoresis-electrospray tandem mass spectrometry (CZE ES-MS/MS), using sample stacking. In addition to the base alkylated 2'-deoxynucleotides present in the DNA-hydrolysate, also phosphate alkylated 2'-deoxynucleotide adducts were identified for TMP and dAMP, An additional adduct, dUMP alkylated on the uridine moiety was found originating from the hydrolytic deamination of dCMP alkylated on N-3 Of the cytosine moiety, Enzymatic hydrolysis using nuclease P1 was incomplete as shown by the presence of dinucleotides alkylated on the base moiety, They were successfully hydrolysed to the corresponding 2'-deoxynucleotides by snake venom phosphodiesterase (SVP), Data are shown indicating that alkylations on the pyrimidine bases were more resistant to enzymatic hydrolysis with nuclease P1 than the purine alkylated products

Occupational choice, number of entrepreneurs and output: theory and empirical evidence with Spanish data

This paper extends the (Lucas, Bell J Econ 9:508–523,1978) model of occupational choices by individuals with different skills, beyond the simple options of self-employment or wage-employment, by including a second choice for the self-employed. That is, an option to hire employees and so become self-employed with employees (SEWEs), or to be self-employed without employees (SEWNEs). We solve for the market equilibrium and examine the sensitivity of relative sizes of occupational groups, and of the level of productivity, to changes in the exogenous parameters. The results show that the positive (negative) association between number of SEWEs (SEWNEs) and productivity, observed in the Spanish data, can be explained, under certain conditions, as the result of cross-region and time differences in average skills. These findings point to the importance of distinguishing between SEWEs and SEWNEs in drawing valid conclusions concerning any link between entrepreneurship and economic development

Variational Principle underlying Scale Invariant Social Systems

MaxEnt's variational principle, in conjunction with Shannon's logarithmic information measure, yields only exponential functional forms in straightforward fashion. In this communication we show how to overcome this limitation via the incorporation, into the variational process, of suitable dynamical information. As a consequence, we are able to formulate a somewhat generalized Shannonian Maximum Entropy approach which provides a unifying "thermodynamic-like" explanation for the scale-invariant phenomena observed in social contexts, as city-population distributions. We confirm the MaxEnt predictions by means of numerical experiments with random walkers, and compare them with some empirical data

Inclusion of Hermetia Illucens larvae or prepupae in an experimental extruded feed: process optimisation and impact on in vitro digestibility

This study investigated the effect of extrusion on digestibility of different blends containing Hermetia illucens (HI) larvae or prepupae. Five blends of HI larvae or prepupae and wheat flour, in a ratio of 25:75, with or without sunflower oil addition, have been formulated as follows: prepupae\u2009+\u2009wheat (no oil); prepupae\u2009+\u2009wheat (low oil); prepupae\u2009+\u2009wheat (medium oil); prepupae\u2009+\u2009wheat (high oil); larvae\u2009+\u2009wheat (no oil). Ether extract (EE) content in different blend was 31.5, 38.9, 46.3, 53.7 and 46.27\u2009g\u2009kg 121 on wet basis (wb), respectively. Blends were homogeneous for moisture (238.9\u2009g\u2009kg 121) and crude protein (112.6\u2009g\u2009kg 121 wb). Feed blends were extruded by a co-rotating, conical twin-screw mini extruder and net torque value (NTV) was recorded as indicator of extrudability. The best performing blend was furtherly tested at four barrel temperatures (60, 70, 80 and 90\u2009\ub0C). In vitro organic matter digestibility (OMD) and in vitro crude protein digestibility (CPD) were measured to evaluate the effect of extrusion process on nutritional value. Increasing the blend EE content up to 53.74\u2009g kg 121 wb, NTV was reduced by four times (<100 Ncm) compared to 31.5 and 38.9\u2009g kg 121 wb EE blends. The best performing mixture was larvae\u2009+\u2009wheat (no oil). Extrusion process increased OMD but not CPD compared to unextruded control, while different extrusion temperature did not affect OMD nor CPD. Concluding, extrusion can contribute to increase OMD in insect containing feed blends. EE content in the blends is a key variable that should be defined in the process

De visserskaai te Oostende (prov. West-Vlaanderen): archeologie van een in de 17de eeuw zwaar geteisterde stad

The Institute for the Archaeological Heritage of the Flemish Community (IAP) has, in close collaboration with the town of Ostend, carried out archaeological excavations during the construction works of the car park below the Visserskaai at Ostend from September 1998 till February 1999. This archaeological work mainly produced information on the eastern ramparts of Ostend and their evolution from the 16th century onwards together with information on the material culture of the inhabitants of Ostend during this same period. The town of Ostend had no defences until late in the 16th century as initial construction work for the defences only started in 1572 when the town came into northern hands. In the beginning of the 17th century Ostend managed to withstand successfully, with its newly built ramparts, for three years an overwhelming Spanish army siege. This was only possible thanks to the fact that the Spaniards never managed to seal of Ostend completely from the sea. As a result, victuals and soldiers arrived continuously at Ostend during the siege. It was only after the arrival of Spinola in the besieging camp, at the end of 1603, that Ostend was gradually forced to surrender. At the bottom of the excavated car park trench, some 4 m below the actual street level, wooden structures of the earthen ramparts were preserved (figs. 4-5). The presence of these con- firms historical data about the use of wood to strengthen the earthen ramparts. The excavations however documented mainly features from 2 bastions, the Peckels bastion and the Spanish bastion (fig. 2-3). Human burials and a gunpowder-magazine (figs. 7, 8, 10, 12) were uncovered in the Peckels bastion and human burials and an open-air rainwater reservoir were detected in the Spanish bastion. The human burials are studied elsewhere in this volume together with other post-medieval burials from Ostend recently discovered outside regular cemeteries. Archaeological material found in connection with the gunpowder-magazine in the Peckelf bastion dates from the 2nd half of the 16th /1st half of the 17th century (figs. 6,9,13-15) and suggests that the construction of this gunpowder-magazine? has to be situated somewhere in the middle of the 17th century, in other words in the period when the town defences of Ostend were adapted to new standards after the above- mentioned siege. A typical object related to the siege is a funnel-shaped gunpowder-flask in a copper-alloy (fig. 6). The inner wall of the gunpowder-magazine was erected on a framework of horizontal wooden beams, which were themselves resting on vertically placed and sharpened beams, mainly in oak (fig. 8). A dendrochronological analysis of the vertically placed beams produced a terminus post quem, which is far too early to be of any help in the discussion on the gunpowder-magazine. The technical differences between the inner and outer wall of the gunpowder-magazine suggest at least 2 phases for this building. The above-mentioned ceramics consist of redwares, Rhenish stone- wares a.o. Raeren, maiolicas, Weser slipwares, olive jars from Seville and some whitewares with green or yellow glaze. The archaeological material from the open- air rainwater reservoir in the Spanish bastion dates from the 2nd half of the 17th/1st half of the 19th century but mainly from the 18th century (figs. 16-32). The collection of ceramics from this context is largely dominated by tablewares. Among these stonewares are nearly missing and replaced by faience, china and industrial white- wares (pearl and cream wares). Maiolica has been nearly completely replaced by faience. Maiolicas remain in fact only important as wall-tiles. The collection contains some olive jars from Seville, a bowl from Dèsvres and a few products from Beauvais. The collection of china mainly consists of cups and small dishes in blue and white china. The china has been brought to Ostend in great quantities in the 18th century, first by the Ostend Company and later by mariners from Ostend in Foreign Service, mainly as ship's ballast. Besides ceramics this context also produced several finds in leather, glass, stone and metal. The leather finds mainly consist of shoes. The glass collection is largely dominated by cylindrical and globular bottles of which one was still intact including its cork (fig. 26: 1). Metal is represented by 22 cast iron cannon balls (fig. 28) and by a standard measure for bottles from an unidentified town inspector of measures and weights of Ostend with GS initials (fig. 27: 8). Small quantities of animal remains were found dispersed over many contexts within the site's stratigraphy. Only three of them are meaningful: a deposit found under the floor of the gunpowder-magazine (table 1: context A), an assemblage excavated in leveling layers within the Peckels bastion (table 1: context B), and material found in the water reservoir in the Spanish bastion (table 1: context C). All connections consisted of larger material; sieved samples did not yield meaningful numbers of smaller animal remains. Context A dates from the second half of the 16th to the first half of the 17th century and consists of consumption refuse: marine molluscs, marine fish bones, bird bone and the remains of cattle, sheep and pig. Context B is contemporaneous to context A and also represents consumption refuse with a similar composition. Remarkable are only a series of vertebrae of a large specimen of ling, a fish that must have been caught in northern waters, and a number of skeletal elements of a gurnard species. Context C has a younger date (second half of the 17th century to the first half of the 19th century) and has a mixed origin in terms of the taphonomy of the animal remains. Not only consumption refuse is present but also parts of the skeletons of at least four dogs and a horse. It is possible that all three contexts represent secondary refuse; in any case their provenance remains unknown. The material certainly has limited value for the interpretation of former consumption patterns. A feature of special interest is the presence of a few cowrie shells. Several aspects of the material culture reflect the maritime character of the town: the presence of several imports such as olive jars from Seville and specific objects as a token in lead (fig. 13: 16) probably used by skippers for the payment of fees and/or tolls. The presence of an important percentage of china and of some cowrie shells is probably related to the activities of the Ostend Company in the l8th century. The pottery discovered from both contexts (2nd half 16th century/ 1 st half 17th century and 2nd half 17th century/ 1st half 19th century) follows the general trends described for post-medieval Flanders

Comparison of the isolation of adducts fo 2'-deoxycytidine and 2'-deoxyguanosine with phenylglycidyl ether by high-performance liquid chromatography on a reversed-phase column and a polystyrene-divinylbenzene column

2'-Deoxycitidine (dCyd) and 2'-deoxyguanosine (dGuo) were subjected to reaction with phenylglycidyl ether (PGE) in methanol in order to study the formation of the corresponding 2'-deoxynucleoside adducts. Separation methods were developed on analytical and semi-preparative scales using high-performance liquid chromatography with photodiode-array detection on a reversed-phase column and on a polystyrene-divinylbenzene column. The use of the latter column was prompted by decomposition of the preparatively isolated dGuo-PGE adducts on the reversed-phase column. The use of a polystyrene-divinylbenzene column solved this problem and also revealed the presence of one more peak in both the dCyd-and dGuo-PGE reaction mixtures.The adducts of dCyd and dGuo were isolated on preparative reversed-phase and polystyrene-divinylbenzene columns and characterized by UV, fast atom bombardment mass and 360 MHz 1H NMR spectrometry. The adducts of dCyd were the diastereomers of N-3-(2-hydroxy-3-phenoxypropyl)-2'-deoxycytidine and N4-(2-hydroxy-3-phenoxypropyl)-2'-deoxycytidine whereas those of dGuo were the two diastereomers of N-7-(2-hydroxy-3-phenoxypropyl)-2'-deoxyguanosine and a third peak which appeared to be mainly (N2-(2-hydroxy-3-phenoxypropyl)-2'-deoxyguanosine.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29601/1/0000690.pd