Mitochondrial DNA lineages of Italian Giara and Sarcidano horses

Giara and Sarcidano are 2 of the 15 extant native Italian horse breeds with limited dispersal capability that originated from a larger number of individuals. The 2 breeds live in two distinct isolated locations on the island of Sardinia. To determine the genetic structure and evolutionary history of these 2 Sardinian breeds, the first hypervariable segment of the mitochondrial DNA (mtDNA) was sequenced and analyzed in 40 Giara and Sarcidano horses and compared with publicly available mtDNA data from 43 Old World breeds. Four different analyses, including genetic distance, analysis of molecular variance, haplotype sharing, and clustering methods, were used to study the genetic relationships between the Sardinian and other horse breeds. The analyses yielded similar results, and the FST values indicated that a high percentage of the total genetic variation was explained by between-breed differences. Consistent with their distinct phenotypes and geographic isolation, the two Sardinian breeds were shown to consist of 2 distinct gene pools that had no gene flow between them. Giara horses were clearly separated from the other breeds examined and showed traces of ancient separation from horses of other breeds that share the same mitochondrial lineage. On the other hand, the data from the Sarcidano horses fit well with variation among breeds from the Iberian Peninsula and North-West Europe: genetic relationships among Sarcidano and the other breeds are consistent with the documented history of this breed

Effects of enzymatic treatment and refining on the properties of recycled pulp

The effect of refining and enzymatic treatment on secondary fibre properties is shown. The following treatment sequences were studied: (i) refining; (ii) refining + enzymatic treatment; (iii) enzymatic treatment + refining; (iv) enzymatic treatment. The effectiveness of the methods was evaluated by measuring physical and mechanical properties of pulp and paper (drainage rate, burst, tensile and tear indexes). The obtained data revealed that combined refining and enzymatic treatment can be considered as a valuable methodology to upgrade recycled pulps. The first is responsible for increasing burst and tensile resistance. The second, if developed under controlled conditions, alloes better drainage, with only slight variation on paper mechanical properties

Enzymatic modification of paper fibres

The enzymatic mode of action in paper fibre upgrading is still uncertain. In an attempt to clarify how enzymes modify pulp and paper properties, several parameters were analysed in the present work: (i) thermal analysis of the water–solid surface interactions; (ii) fibre cake permeability; (iii) particle size analysis. The results obtained suggest that enzymes modify the interfacial properties of fibres, increasing the water affinity, which in turn change the technical properties of pulp and paper, such as drainability and strength. The modification of paper and pulps following a treatment with cellulosebinding domains further supports this hypothesis

Refining and enzymatic treatment of secondary fibres for paperboard production : Cyberflex measurements of fibre flexibility

Recycling is generally affected by secondary fibre quality. High temperature and pressure during the drying stage causes irreversible changes in fibre morphology, which is the mainly responsible for the considerable reduction in the swelling and bonding ability (strength and number of bonds) [1, 2, 3]. Additionally, the reduced dewatering ability of these pulps is a major problem during paper manufacture as they decrease the speed on the paper machine and worsen sheet formation [4]. Secondary fibre upgrade is difficult and sometimes unpredictable, as the samples to be treated vary along with their history. Traditional upgrade methodologies have been used to improve secondary fibre properties, but the results are most of the times insufficient [1, 5]. Different reports suggest that treating pulps with enzymes and refining could overcome these problems [4, 6, 7, 8, 9]. More recently, Cellulose-Binding Domains (CBD’s) usage has been shown as an interesting tool to modify recycled fibres properties

Enzymatic versus chemical deinking of non-impact ink printed paper

Enzymatic versus chemical deinking is examined for MOW and photocopy prints. Several enzymatic preparations and two fibre/ink particle separation methods are tested. Deinking was monitored by image analysis and standard pulp and paper characterisation procedures. The effectiveness of the fibre/ink particle separation method depends on the ink particle’s size: for smaller particles a washing step is recommended whereas for larger particles, the use of flotation is necessary. The enzymatic treatment is a competitive alternative for MOW and photocopy paper deinking. However, the process requires the selection of an adequate enzymatic preparation for each paper grade

Tecnologias alternativas para a melhoria das características da fibra secundária

O presente trabalho tem por objectivo o estudo da utilização de enzimas e domínios das enzimas responsáveis pela ligação à celulose (Cellulose Binding Domains - CBD's) para melhoria das propriedades de fibra secundária. Uma amostra de fibra secundária proveniente da desintegração de cartão (Portucel Viana) foi tratada por via enzimática e por adição de CBD's. O tratamento enzimático permitiu o aumento da drenabilidade, embora as propriedades de resistência tenham diminuído. A adição de CBD's conduziu a resultados bastante satisfatórios, permitindo o aumento simultâneo da drenabilidade da pasta e da resistência do papel

Modification of secondary pulp fibre fractions by enzymatic treatment

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Preliminary studies on enzymatic deinking

Results on enzymatic deinking of paper pulps are shown. The process includes paper pulping, with an enzymatic cocktail, followed by flotation and dewatering. Three different wastepaper samples were used and tested. The deinking of the pulp was monitored by image analysis. Physical, mechanical and optical properties of pulp and paper were also determined. The obtained data revealed the effectiveness of the assayed enzyme preparation. However, enzyme use needs further optimisation as paper strenght properties suffered important alteration

Short communication: Study on epilithic diatoms in the Kozluk Creek (Arapgir-Malatya, Turkey)

Being the most important members of phytoplankton and phytobenthos, both of which are the primary producers of surface water resources, algae play a very important role in the biological productivity of waters with their oxygen production through photosynthesis and they synthesize the organic materials. Furthermore, with their high levels of protein, algae are used as human and animal food as well as being used in the production of organic fertilizers and organic vitamins. Another reason for algae currently being among the most researched organisms is their easy and inexpensive productions in culture media. With the recognition of the importance of algae in standing waters and streams, the number of studies conducted on these organisms has rapidly increased. In Turkey, the number of studies on algae in streamsis quite high [(Altuner and Gurbuz (1989), Altuner and Gurbuz (1991) Yıldız (1991) , Yildiz and Ozkiran (1994), Ertan and Morkoyunlu (1998), Sahin (1998), Cetin and Yavuz (2001), Solak et al. (2012), Sivaci and Dere (2007), Mumcu et al. (2009), Pala and Caglar (2008)]

A comparative study of two phenomenological models of dephasing in series and parallel resistors

We compare two phenomenological models of dephasing that are in use recently. We show that the stochastic absorption model leads to reasonable dephasing in series (double barrier) and parallel (ring) quantum resistors in presence and absence of magnetic flux. For large enough dephasing it leads to Ohm's law. On the other hand a random phase based statistical model that uses averaging over Gaussian random-phases, picked up by the propagators, leads to several inconsistencies. This can be attributed to the failure of this model to dephase interference between complementary electron waves each following time-reversed path of the other.Comment: 7 pages, 9 figure