Recurrence of Mitotically Active Cellular Fibroma of the Ovary

Background. 10% of ovarian fibromatous tumours typically exhibit increased cellularity, mitotic activity, and less frequently nuclear atypia. Therefore, the classification within the group of fibromatous tumours may represent some difficulties, thus, one or several of these features should appear. Case. We introduce the clinical and pathologic features based on one case of recurrence of a mitotically active cellular ovarian fibroma (MACF) in the pararectal fossa. This recurrence took place six years after primary surgery. Macroscopically, the tumour was firm, fibrous, well delimited, yellow-white without gross necrosis. On microscopic examination, it was composed of a densely cellular proliferation of fibrolastic-like cells with bland nuclear features and arranged in a fascicular pattern. There was no sign of significant atypia or necrosis. Conclusion. Recently, this case is the first report of a recurrence of MACF, following primary surgery with no tumoral rupture or surgical difficulty. The clinical outcome of ovarian cellular fibromas (CFs) and MACFs is typically uneventful. This case, however, strongly suggests maintaining a long-term clinical follow-up even though the principal tumour was surgically treated without tumour rupture or in the absence of adherence or any surgical difficulty

Almost one century of forest inventory data: how bright are the prospects for the Finnish forest biodiversity?

With 73% forest cover and 26.2 million ha of forestry land, Finland is the most forested country in Europe, hence contributing significantly to its forest biodiversity. The forestry land is classified into forest land (20.3 mill. ha), poorly productive forest land (2.5 mill. ha) and unproductive land (3.2 mill. ha), depending on the potential annual increment. The majority of nature conservation areas (3/4 of the land) are located on the poorly productive and unproductive forest land, making them susceptible to fragmentation and isolation as a result of forestry-driven habitat changes on the dominant productive forest land. Here I present a detailed historical overview of ecological changes that took place in the Finnish forests within 1924-2013 and discuss their implications for biodiversity conservation. Despite the 13% reduction in forest area in the 1940s due to the territory loss in World War II, Finland's tree growing stock has never been so high. Yet, the tree species composition, age structure and soil hydrology of the forest, three key drivers of the boreal forest biodiversity, have radically changed in just a few decades, with marked differences between the north and the south. On the productive forest land, pine trees have become increasingly dominant at the expense of spruce forests, raising concerns for the spruce-associated biota. In Northern Finland especially, right after the war, the pine forest cover has steadily increased from 55 to 75% while the spruce cover declined from 31 to 16%. Similar changes took place in the south from the 1960s. An abrupt decline in the amount of deciduous forests is another nationwide post-war phenomenon, causing its original cover to drop from 17 to 8% by 1984. It is only recently that deciduous forests have increased again in proportion, accounting now for 11.5% of the southern forest land, although being of limited ecological value due to their younger age. In addition to tree species composition, the simultaneous large-scale implementation of both clear-cutting and forest ditching practices that mainly took place from early 60s to late 90s, with a peak in the 70s, have caused fundamental changes in the original age structure and productivity of the forest. Today, in Northern Finland where they are mostly situated, species-rich natural forests over 120, 140 and 160 yr old only represent 17, 14 and 10% of the regional forest land. This is a pale figure compared to their 55, 45 and 36% respective coverage in the early 1920s. Based on linear regressions, the continuously declining primeval forests, despite their prime importance for the boreal biodiversity, are expected to largely vanish from the Finnish productive forest land by the beginning of the next century unless adapted new conservation measures are taken. It took at least 40 years for natural forest mires to be converted into dry production forests, demonstrating long-lasting effects of drainage on the northern ecosystem.peerReviewe

Molecular design of multicomponent polymer systems. XVI. Emulsification of polystyrene and nylon-6 by a reactive block copolymer

peer reviewedOne of the most attractive routes for alloying two incompatible polymers is the use of polymeric emulsifiers. The validity and applicability of this concept were widely demonstrated in the emulsification of polyethylene and polystyrene. This article aims at reporting preliminary results on the emulsification of polystyrene and nylon-6 blends by polystyrene-poly(methyl methacrylate-co-methacrylic acid) diblock copolymers, the carboxylic acid groups resulting from partial hydrolysis of methyl methacrylate units

Molecular design of multicomponent polymer systems. XV. Morphology and mechanical behavior of blends of low density polyethylene with acrylonitrile‐butadiene‐styrene (ABS), emulsified by a poly(hydrogenated butadiene‐b‐methyl methacrylate) copolymer

The emulsifying activity of a poly(hydrogenated butadiene‐b‐methyl methacrylate) (HPB‐b‐PMMA) copolymer is investigated in incompatible blends of a low density polyethylene and poly(styrene‐co‐acrylonitrile) resins (mainly ABS) prepared in the melt state on a two‐roll mill. Optical and scanning electron microscopy observations clearly demonstrate that a moderate amount of copolymer (5 wt %) very significantly decreases the particle size and enhances interfacial adhesion. The block copolymer is also responsible for a strong improvement in both the ductility and Charpy impact resistance of PE/ABS blends. Copyright © 1989 Society of Plastics Engineer

Molecular design of multicomponent polymer systems. XVIII: Emulsification of high‐impact polystyrene and low density polyethylene blends into high‐impact alloys

The interfacial activity of a hydrogenated polybutadiene‐polystyrene tapered diblock copolymer, (HPB‐b‐PS) is investigated in blends of a low density polyethylene (LDPE) with a high impact polystyrene (HIPS) prepared in the melt state on a two‐roll mill. Optical and scanning electron microscopy examinations of smoothed or fracture surfaces and also surfaces obtained after THF‐extraction of PS phases demonstrate that the copolymer promotes the dispersion and interfacial adhesion of the components, whatever the composition and is able to create and stabilize particular dispersions of the rubber particles in these blends. Tensile and Charpy impact properties are also very significantly improved. All these features demonstrate that the ductility and toughness of PS and LDPE/PS blends can be closely controlled by adequate combinations of rubber particles and a HPB‐b‐PS copolymer. Copyright © 1990 Society of Plastics Engineer

Molecular Design of Multicomponent Polymer Systems. 8. New Acrylonitrile-Butadiene-Styrene-like Resins from Styrene-Acrylonitrile-Based Mechanical Blends

One of the main applications of polymer blends is in the manufacture of impact-resistant materials, since phase separation is an essential feature for the rubber toughening of brittle plastics. In acrylonitrile-butadiene-styrene (ABS) resins, the rubbery phase usually consists of polybutadiene, nitrile rubber, or poly(styrene-co-butadiene) rubber (SBR). The largest part of the resins now manufactured is prepared by a graft copolymerization process of styrene and acrylonitrile in the presence of a preformed rubber.1Although mechanical blending remains certainly a very attractive and more versatile way toward these polyblends, it has important deficiencies that cause it to be less efficient than the copolymerization techniques. © 1986, American Chemical Society. All rights reserved

(9-anthracenylmethyl)lithium-initiated living anionic polymerization of alkyl methacrylates

[No abstract available

Interface modification in polymer blends

It is well known that melt blending of immiscible polymer pairs leads to blends with a relatively weak adhesion between coarse phases and, accordingly, with a poor mechanical behavior. This situation can, however, be alleviated by the two strategies discussed. These two strategies are: the tailoring of commodity polymer blends and engineering plastics blends. A discussion is presented of polystyrene-polyolefin model materials and considerations of the role played by diblock copolymers. The preliminary results clearly show that functional groups selectively attached at both ends of linear immiscible chains can control the interfacial situation by promoting thermoreversible interactions

Is the Eurasian Three-toed Woodpecker Picoides tridactylus a keystone species in boreal forest environments?

The Eurasian Three-toed Woodpecker Picoides tridactylus is a widespread species of the northern Palearctic forests. The species prefers mature coniferous and mixed forests, favouring forests with a good proportion of dead and dying trees. Three-toed Woodpecker has a close connection to forest habitats with natural dynamics and disturbances; it inhabits areas recently disturbed by fire, wind, snow, or other agents that increase the amount of suitable substrate of its insect prey. Its diet consists predominantly of spruce bark beetles (Coleoptera, Scolytidae), although phloem sap of conifer trees is also used especially in springtime. We present here results of both published and unpublished studies that are based on long-term population studies in boreal areas in southern and eastern Finland. The territory sites of Three-toed Woodpecker are detected to locate in structurally complex forests, and there is a strong positive correlation with the occupancy proportion of its territories and the quality of the forest landscape. The species is observed to indicate general species richness of forest birds and structural diversity of forest environment. Its breeding density increases along the conservation value of forest landscapes for breeding birds. The Three-toed Woodpecker is also considered a candidate of umbrella species for the bark beetle biodiversity given its requirement for ample dead wood and thereby susceptibility to forest management. The Three-toed Woodpecker is a primary cavity excavator, and its old nest cavities are used by various cavity-nesting bird species in its territories. The species frequently reuses its own cavities, but they have found to be very important for the Pygmy Owl Glaucidium passerinum. However, the general importance of the Three-toed Woodpecker as a cavity-producer in boreal forests is most probably much smaller than that of the Great-spotted Woodpecker Dendrocopos major. Available evidence suggest that the Three-toed Woodpecker may regulate tree-damaging bark beetle populations during an epidemic. This underlines the benefit of protecting the species and its habitats as a means to possibly limit beetle damages in surrounding managed forests. Based on the results and current knowledge, we evaluate the keystone species status and possible economic values of the Three-toed Woodpecker in boreal forest environments. 1. Fayt, P., Machmer, M. M. & Steeger, C. 2005: Regulation of spruce bark beetles by woodpeckers - a literature review. --- Forest Ecology and Management 206: 1--14. 2. Pakkala, T., Hanski, I. & Tomppo, E. 2002: Spatial ecology of the three-toed woodpecker in managed forest landscapes. --- Silva Fennica 36: 279--288. 3. Pakkala, T., Lindén, A., Tiainen, J., Tomppo, E. & Kouki, J. 2014: Indicators of forest biodiversity: which bird species predict high breeding bird assemblage diversity in boreal forests at multiple spatial scales? --- Annales Zoologici Fennici 51: 457--476.peerReviewe