Branch groups with infinite rigid kernel

A theoretical framework is established for explicitly calculating rigid kernels of self-similar regular branch groups. This is applied to a new infinite family of branch groups in order to provide the first examples of self-similar, branch groups with infinite rigid kernel. The groups are analogs of the Hanoi Towers group on 3 pegs, based on the standard actions of finite dihedral groups on regular polygons with odd numbers of vertices, and the rigid kernel is an infinite Cartesian power of the cyclic group of order 2, except for the original Hanoi group. The proofs rely on a symbolic-dynamical approach, related to finitely constrained groups.Comment: Comments welcome

The true prosoluble completion of a group: Examples and open problems

The true prosoluble completion $$P\mathcal S (\Gamma)$$ of a group Γ is the inverse limit of the projective system of soluble quotients of Γ. Our purpose is to describe examples and to point out some natural open problems. We discuss a question of Grothendieck for profinite completions and its analogue for true prosoluble and true pronilpotent completion

Quality of Root Vegetables during Prolonged Storage

The objective of this study was to develop postharvest techniques and technologies of the most important root vegetables: carrots, celeriac and parsnip. Investigations included the effect of harvest maturity (harvest at November or January) and postharvest washing treatments (hot water, H2O2 and NaOCl and non-washed-control) of carrots (Daucus carota ’Bolero F1’), parsnip (Pastinaca sativa ‘Banatski dugi’) and celeriac (Apium graveolens var. rapaceum ‘Mentor’) roots and effects on their quantitative and qualitative changes during different storage conditions (S-1; 0°C and 98% RH or S-2; 0-2°C and 85-92% RH). Water loss and quality changes in these vegetables roots were monitored after 120 and 180 days of storage period (SP). At the end of SP the percentage of water loss ranged from 3.20% (from first harvest inside the S-1 with H2O2 treatment) in carrot to 39.29% (from first harvest inside the S-2 in control) in celeriac root. The dry matter content (DM) increased during storage period. Total sugar content (TSC) in the roots depends on year and harvest time. During SP, total sugar content increased more in S-2 cooling room. The parsnip root was characterized by more hardness texture relative to the carrot and celeriac roots. During SP carrot root loses the flexibility. The most effective method of maintaining quality of root vegetables is optimal harvest time followed by prestorage washing treatments (H2O2 or NaOCl) and storage at optimum temperature (0 ºC) with a high relative humidity 98%

Effect of 1-methylcyclopropene on the antioxidant capacity and postharvest quality of tomato fruit

Tomato fruits ‘1402’ were harvested at mature green (MG), light pink (LP) and light red (LR) stages and treated with 0.3 μL L-1 of 1-methylcyclopropene (1-MCP) at 20°C for 24 h to investigate the ability to retard tomato fruit ripening. The treated and control fruit were stored at 5°C and 12 oC for 14 days and a further 4 days at 20oC for a shelf life period. The results show that the effects of 1-MCP on fruit ripening were related to the stage of maturity and storage temperature. The MG stage was the optimal stage for 1-MCP treatment when fruit storage was at 12°C. 1-MCP treatment reduced the lipophilic antioxidant activity (LAA) of the tomato fruit, but the hydrophilic antioxidant activity (HAA) remained similar to that observed at harvest. 1-MCP is a potential tool for extending shelf life, delaying tomato fruit ripening (slowing color development and firmness loss) and enhancing quality of tomatoes.Keywords: Tomato, 1-MCP, storage, stage of maturity, temperatureAfrican Journal of Biotechnology Vol. 12(6), pp. 547-55

Finite self-similar p-groups with abelian first level stabilizers

We determine all finite p-groups that admit a faithful, self-similar action on the p-ary rooted tree such that the first level stabilizer is abelian. A group is in this class if and only if it is a split extension of an elementary abelian p-group by a cyclic group of order p. The proof is based on use of virtual endomorphisms. In this context the result says that if G is a finite p-group with abelian subgroup H of index p, then there exists a virtual endomorphism of G with trivial core and domain H if and only if G is a split extension of H and H is an elementary abelian p-group.Comment: one direction of theorem 2 extended to regular p-group

Utjecaj malčiranja na kontrolu korova i agronomska svojstva salate

Istraživanja su imala za cilj odrediti značaj utjecaja zastiranja tla različitim vrstama malča na kontrolu korova, prinos i kvalitetu dvije sorte salate (Lactuca sativa var. capitata) ‘Mafalda’ i ‘Bataille. Primjena zastiranja se odražava na povećanje temperature tla, Ispod crne polietilenske folije temperature tla je bila za 2˚С viša u usporedbi s temperaturom ispod bijelo/crne folije i agrotekstila, i za 3-5˚С u odnosu na zastiranje organskim malčem (karton, slama, piljevina, kompost) i kontrolu (ne malčirano tlo). U suzbijanju korovnih vrsta, polietilenske folije su pokazale mnogo veću učinkovitost (95,1-97,8 %) u usporedbi s organskim malčem. Najveća prisutnost korova bila je na malču sa slamom (46 biljaka/m²) u usporedbi s kontrolom (23 biljaka/m²). Pri malčiranju kompostom prinos je bio značajno do vrlo značajno veći (‘Bataille’- 4,64 kg/m² ; Mafalda’ 4,98 kg/m²) u odnosu na ostale tretmane. Malčiranje slamom kod sorte ‘Bataille’ doprinijelo je smanjenom prinosu (2,80 kg/m²). Malčiranje kompostom i crnom polietilenskom folijom utječe na značajno povećanje mase po biljci i indeks lisne površine, kao osnovnih parametara prinosa. Sorta ‘Mafalda’ je u uvjetima zastiranja pokazala veću otpornost na fiziološke poremećaje u usporedbi sa sortom ‘Bataille’

Zoran S. ILIĆ, Lidija MILENKOVIĆ, Ljubomir ŠUNIĆ, Ljiljana STANOJEVIĆ Marija BODROŽA-SOLAROV, Dušan MARINKOVIĆ 47th Croatian and 7th International Symposium on Agriculture Tomato fruits quality as affected by light intensity using color shade nets

Abstract The quality of tomatoes were affected by environmental factors (light and temperature) and agronomic techniques used (open field or plastic-house production). Fruits produced in a plastic-houses were more acidic (greater TA, 0.38) than field-produced fruits (0.34). Fruit grown in the field had greater TSS content (5.42 o Brix) than tomato from protected environment (5.10). Fruits produced in the field had greater TSS:TA ratios than those produced in a protected environment. Significantly higher lycopene content was observed in plastic-houses tomato integrated with red shade netting technologies (64.9 μg g −1 ) than in field-grown tomatoes (48.1 μg g −1 ). By contrast, shaded fruits have lower content of β-carotene