Quantitative estimators of structure in chosen stands of common oak and hornbeam (Carpino betuli – Quercetum roboris Anić 1959 / em. Rauš 1969)

Gospodarenje šumom podrazumijeva zahvate koji utječu na prostornu strukturu, odnosno raspored stabala, kao i na raznolikost vrsta unutar sastojine. Bioraznolikost i prostorna struktura opisuje se najčešće kvalitativno opisima ili kvantitativno indeksima bioraznolikosti i prostorne strukture razvijenim u tu svrhu. Cilj ovog rada je na pokusnim plohama u sastojinama hrasta lužnjaka i običnoga graba (Carpino betuli – Quercetum roboris, Anić 1959 / emend. Rauš 1969.) analizirati strukturu pomoću BWINPro programa za analizu i prognozu rasta šumskih sastojina. Kvantitativni elementi strukture opisani su indeksima raznolikosti vrsta (bogatstva vrsta, Shannonov i standardizirani Shannonov) i njihove prostorne strukture (Clark & Evansov indeks agregacije, Pielou indeks segregacije vrsta).Forest management implies activities that affect spatial structure and distribution of trees as well as the diversity of forest tree species within the stand. Biodiversity and spatial structure are commonly described with qualitative descriptions or quantitatively indexes (estimators) of biodiversity or spatial structure developed for this purpose. Aim of this work is to quantitatively analyse species and spatial structures on plots in mixed stands of Common oak and Hornbeam using BWINPro program for analysis and prognosis of forest stands. Elements of structure were quantified with indexes of species composition (species diversity, Shannon index, Evenness) and of spatial distributions (Clark & Evans index of aggregation, Pielou index of segregation)

Quantitative estimators of structure in chosen stands of common oak and hornbeam (Carpino betuli – Quercetum roboris Anić 1959 / em. Rauš 1969)

Gospodarenje šumom podrazumijeva zahvate koji utječu na prostornu strukturu, odnosno raspored stabala, kao i na raznolikost vrsta unutar sastojine. Bioraznolikost i prostorna struktura opisuje se najčešće kvalitativno opisima ili kvantitativno indeksima bioraznolikosti i prostorne strukture razvijenim u tu svrhu. Cilj ovog rada je na pokusnim plohama u sastojinama hrasta lužnjaka i običnoga graba (Carpino betuli – Quercetum roboris, Anić 1959 / emend. Rauš 1969.) analizirati strukturu pomoću BWINPro programa za analizu i prognozu rasta šumskih sastojina. Kvantitativni elementi strukture opisani su indeksima raznolikosti vrsta (bogatstva vrsta, Shannonov i standardizirani Shannonov) i njihove prostorne strukture (Clark & Evansov indeks agregacije, Pielou indeks segregacije vrsta).Forest management implies activities that affect spatial structure and distribution of trees as well as the diversity of forest tree species within the stand. Biodiversity and spatial structure are commonly described with qualitative descriptions or quantitatively indexes (estimators) of biodiversity or spatial structure developed for this purpose. Aim of this work is to quantitatively analyse species and spatial structures on plots in mixed stands of Common oak and Hornbeam using BWINPro program for analysis and prognosis of forest stands. Elements of structure were quantified with indexes of species composition (species diversity, Shannon index, Evenness) and of spatial distributions (Clark & Evans index of aggregation, Pielou index of segregation)

Quantitative estimators of structure in chosen stands of common oak and hornbeam (Carpino betuli – Quercetum roboris Anić 1959 / em. Rauš 1969)

Gospodarenje šumom podrazumijeva zahvate koji utječu na prostornu strukturu, odnosno raspored stabala, kao i na raznolikost vrsta unutar sastojine. Bioraznolikost i prostorna struktura opisuje se najčešće kvalitativno opisima ili kvantitativno indeksima bioraznolikosti i prostorne strukture razvijenim u tu svrhu. Cilj ovog rada je na pokusnim plohama u sastojinama hrasta lužnjaka i običnoga graba (Carpino betuli – Quercetum roboris, Anić 1959 / emend. Rauš 1969.) analizirati strukturu pomoću BWINPro programa za analizu i prognozu rasta šumskih sastojina. Kvantitativni elementi strukture opisani su indeksima raznolikosti vrsta (bogatstva vrsta, Shannonov i standardizirani Shannonov) i njihove prostorne strukture (Clark & Evansov indeks agregacije, Pielou indeks segregacije vrsta).Forest management implies activities that affect spatial structure and distribution of trees as well as the diversity of forest tree species within the stand. Biodiversity and spatial structure are commonly described with qualitative descriptions or quantitatively indexes (estimators) of biodiversity or spatial structure developed for this purpose. Aim of this work is to quantitatively analyse species and spatial structures on plots in mixed stands of Common oak and Hornbeam using BWINPro program for analysis and prognosis of forest stands. Elements of structure were quantified with indexes of species composition (species diversity, Shannon index, Evenness) and of spatial distributions (Clark & Evans index of aggregation, Pielou index of segregation)

Dielectric relaxation of DNA aqueous solutions

We report on a detailed characterization of complex dielectric response of Na-DNA aqueous solutions by means of low-frequency dielectric spectroscopy (40 Hz - 110 MHz). Results reveal two broad relaxation modes of strength 20<\Delta\epsilon_LF<100 and 5<\Delta\epsilon_HF<20, centered at 0.5 kHz<\nu_LF<70 kHz and 0.1 MHz<\nu_HF<15 MHz. The characteristic length scale of the LF process, 50<L_LF<750nm, scales with DNA concentration as c_DNA^{-0.29\pm0.04} and is independent of the ionic strength in the low added salt regime. Conversely, the measured length scale of the LF process does not vary with DNA concentration but depends on the ionic strength of the added salt as I_s^{-1} in the high added salt regime. On the other hand, the characteristic length scale of the HF process, 3<L_HF<50 nm, varyes with DNA concentration as c_DNA^{-0.5} for intermediate and large DNA concentrations. At low DNA concentrations and in the low added salt limit the characteristic length scale of the HF process scales as c_DNA^{-0.33}. We put these results in perspective regarding the integrity of the double stranded form of DNA at low salt conditions as well as regarding the role of different types of counterions in different regimes of dielectric dispersion. We argue that the free DNA counterions are primarily active in the HF relaxation, while the condensed counterions play a role only in the LF relaxation. We also suggest theoretical interpretations for all these length scales in the whole regime of DNA and salt concentrations and discuss their ramifications and limitations.Comment: 15 pages, 9 figure

FEED ADDITIVES INCREASE INTAKE OF THE MOST IMPORTANT TANNIN- AND TERPENE-RICH SHRUBS IN THE MEDITERRANEAN MAQUIS

U šest pokusa istraživan je učinak energije (ječma), polietilen-glikola (PEG; pokus: 1 – 3), aktivnog ugljena (AU; pokus 4 – 6) i različitog broja ponuđenih vrsta grmova na hranidbene navike ovaca i koza. U prvom pokusu ovcama i kozama ponuđena su 3 grma, u drugom 2 grma i u trećem pokusu 1 grm s visokim sadržajem tanina, dok su na isti način u četvrtom pokusu ovcama i kozama ponuđena tri grma, u petom pokusu dva grma i u šestom pokusu jedan grm s visokim sadržajem terpena. U prvom pokusu, ovce prihranjivane ječmom i PEG-om više su konzumirale (P=0,002) biomase grmova Quercus ilex, Arbutus unedo i Pistacia lentiscus u odnosu na kontrolnu skupinu, ali takav učinak nije utvrđen u koza. U drugom pokusu, kada su ovcama i kozama ponuđena 2 grma (Arbutus unedo i Pistacia lentiscus), dodatak ječma i PEG-a imao je pozitivan učinak (P 2 > 1 grma, a isto tako, kombinacija više različitih vrsta grmova ponuđenih životinjama pridonosi većem unosu hrane. Naši rezultati podupiru hipotezu da biološka/ biokemijska raznolikost igra važnu ulogu u izboru hrane biljojeda, te im omogućava bolje zadovoljavanje hranidbenih potreba s jedne strane i izbjegavanje trovanja fitotoksinima s druge strane.In six trials, the effect of energy (barley), polyethylene glycol (PEG; trials 1- 3), activated charcoal (Ach; trials 4 -6) and number of Mediterranean shrubs offered to sheep and goats was examined. Three shrubs with high tannin content were offered in trial 1, 2 shrubs in trial 2 and 1 shrub in trial 3, likewise 3 shrubs with a high terpene content in trial 4, 2 shrubs in trial 5 and 1 shrub in trial 6. In trial 1, sheep receiving both PEG and barley ate more (P=0.002) total shrubs (Quercus ilex, Arbutus unedo and Pistacia lentiscus) than did controls, but no such treatment effect was found for goats. In trial 2, supplemental PEG and barley had a positive effect (P 2 > 1 shrubs to animals and also combinations of more shrubs offered to animals promoted greater intake. Our findings suggest that biological/biochemical diversity plays a very important role in herbivore’s diet selection, enabling animals to better meet their nutritional needs and avoid toxicity

FEED ADDITIVES INCREASE INTAKE OF THE MOST IMPORTANT TANNIN- AND TERPENE-RICH SHRUBS IN THE MEDITERRANEAN MAQUIS

U šest pokusa istraživan je učinak energije (ječma), polietilen-glikola (PEG; pokus: 1 – 3), aktivnog ugljena (AU; pokus 4 – 6) i različitog broja ponuđenih vrsta grmova na hranidbene navike ovaca i koza. U prvom pokusu ovcama i kozama ponuđena su 3 grma, u drugom 2 grma i u trećem pokusu 1 grm s visokim sadržajem tanina, dok su na isti način u četvrtom pokusu ovcama i kozama ponuđena tri grma, u petom pokusu dva grma i u šestom pokusu jedan grm s visokim sadržajem terpena. U prvom pokusu, ovce prihranjivane ječmom i PEG-om više su konzumirale (P=0,002) biomase grmova Quercus ilex, Arbutus unedo i Pistacia lentiscus u odnosu na kontrolnu skupinu, ali takav učinak nije utvrđen u koza. U drugom pokusu, kada su ovcama i kozama ponuđena 2 grma (Arbutus unedo i Pistacia lentiscus), dodatak ječma i PEG-a imao je pozitivan učinak (P 2 > 1 grma, a isto tako, kombinacija više različitih vrsta grmova ponuđenih životinjama pridonosi većem unosu hrane. Naši rezultati podupiru hipotezu da biološka/ biokemijska raznolikost igra važnu ulogu u izboru hrane biljojeda, te im omogućava bolje zadovoljavanje hranidbenih potreba s jedne strane i izbjegavanje trovanja fitotoksinima s druge strane.In six trials, the effect of energy (barley), polyethylene glycol (PEG; trials 1- 3), activated charcoal (Ach; trials 4 -6) and number of Mediterranean shrubs offered to sheep and goats was examined. Three shrubs with high tannin content were offered in trial 1, 2 shrubs in trial 2 and 1 shrub in trial 3, likewise 3 shrubs with a high terpene content in trial 4, 2 shrubs in trial 5 and 1 shrub in trial 6. In trial 1, sheep receiving both PEG and barley ate more (P=0.002) total shrubs (Quercus ilex, Arbutus unedo and Pistacia lentiscus) than did controls, but no such treatment effect was found for goats. In trial 2, supplemental PEG and barley had a positive effect (P 2 > 1 shrubs to animals and also combinations of more shrubs offered to animals promoted greater intake. Our findings suggest that biological/biochemical diversity plays a very important role in herbivore’s diet selection, enabling animals to better meet their nutritional needs and avoid toxicity

DNA End Resection Controls the Balance between Homologous and Illegitimate Recombination in Escherichia coli

Even a partial loss of function of human RecQ helicase analogs causes adverse effects such as a cancer-prone Werner, Bloom or Rothmund-Thompson syndrome, whereas a complete RecQ deficiency in Escherichia coli is not deleterious for a cell. We show that this puzzling difference is due to different mechanisms of DNA double strand break (DSB) resection in E. coli and humans. Coupled helicase and RecA loading activities of RecBCD enzyme, which is found exclusively in bacteria, are shown to be responsible for channeling recombinogenic 3′ ending tails toward productive, homologous and away from nonproductive, aberrant recombination events. On the other hand, in recB1080/recB1067 mutants, lacking RecBCD’s RecA loading activity while preserving its helicase activity, DSB resection is mechanistically more alike that in eukaryotes (by its uncoupling from a recombinase polymerization step), and remarkably, the role of RecQ also becomes akin of its eukaryotic counterparts in a way of promoting homologous and suppressing illegitimate recombination. The sickly phenotype of recB1080 recQ mutant was further exacerbated by inactivation of an exonuclease I, which degrades the unwound 3′ tail. The respective recB1080 recQ xonA mutant showed poor viability, DNA repair and homologous recombination deficiency, and very increased illegitimate recombination. These findings demonstrate that the metabolism of the 3′ ending overhang is a decisive factor in tuning the balance of homologous and illegitimate recombination in E. coli, thus highlighting the importance of regulating DSB resection for preserving genome integrity. recB mutants used in this study, showing pronounced RecQ helicase and exonuclease I dependence, make up a suitable model system for studying mechanisms of DSB resection in bacteria. Also, these mutants might be useful for investigating functions of the conserved RecQ helicase family members, and congruently serve as a simpler, more defined model system for human oncogenesis

ASSESSMENT OF CORRECTION FACTORS OF BEEF COLOUR STABILIZATION

Boja junećega mesa je jedan od temeljnih kvalitativnih obilježja koji značajno utječe na percepciju potrošača o poželjnosti namirnice. Svijetlocrvena boja mesa potrošaču je kvalitativno prihvatljivija, dok tamnocrvena boja mesa potiče nepoželjne asocijacije o kakvoći junećeg mesa, premda često takav stav nema objektivno uporište. Mesu je svojstveno da nakon izlaganja zraku, mioglobin u površinskom sloju mišića određeno vrijeme intenzivno veže kisik mijenjajući svoj oblik, a time i boju površine mišića. Cilj rada je, praćenjem promjena vrijednosti parametara boje junećega mesa (CIE L*a*b*) tijekom 60-minutne stabilizacije boje, procijeniti korekcijske faktore parametara. Utvrđeno je da L* parametar boje junećeg mesa treba najkraće vrijeme stabilizacije i njegova se vrijednost nakon prvog mjerenja ne mijenja značajno. Vrijednost a* parametra boje junećeg mesa značajno se razlikovala (p<0,001) do trećeg mjerenja (a*_30), dok se b* parametar značajno mijenjao (p<0,05) do četvrtog mjerenja (b*_45). Korekcijski faktori boje junećeg mesa gotovo istodobno ostvaruju nulte vrijednosti (L*_46 min, a*_50 min, b*_50 min). Zaključujemo da za stabilizaciju a* i b* parametara boje junećeg mesa treba duže vremensko razdoblje. Faktori korekcije parametra boje mesa izračunati na osnovi razlika prosječnih vrijednosti mjerenja mogu poslužiti u objektiviziranju mjerenja koja trebaju uvažavati kraće vremensko razdoblje od otvaranja mišića do mjerenja boje junećeg mesa.Beef colour is one of the most important quality factors that determine whether a meat cut will be purchased. Consumers find light red meat colour acceptable, while dark purple colour of meat is associated with doubtful quality and freshness. In meat, shortly after opening the surface to air, myoglobin has the ability to intensively bind oxygen resulting in changing myogloin status and meat colour. The aim of this work was to estimate adjustment factors for beef meat colour readings (CIE L*a*b*) during 60 minute bloom time. Relative differences among carcasses in L* value did not change after 15 minutes, while a* values changed up to 30 minute after bloom time. The b* values continued to increase up to 60 minutes of bloom time. According to adjustment factors, L*, a* and b* values stabilized after approximately the same time (L*_46 min, a*_50 min, b*_50 min). According to mean differences in L*, a* and b* values adjustment factors for beef colorimeter readings were calculated. They can be used for more objective determination of beef colour measured at different time intervals