All-optical 3D blue phase photonic crystal switch with photosensitive dopants.

Blue phase (BP) liquid crystals (LC) have lately become the focus of extensive research due to their peculiar properties and structure. BPs exhibit a highly organized 3D structure with a lattice period in the hundreds of nm. Owing to such structure, BPs are regarded as 3D photonic crystals. The unique properties of this complex LC phase are achieved by the self-assembly of the LC molecules into periodic cubic structures, producing bright selective Bragg reflections. Novel applications involving 3D photonic crystals would certainly benefit from enhanced ground-breaking functionalities. However, the use of BPs as 3D has been traditionally curtailed by the BP crystals trend to grow as random polycrystals, making it difficult to develop practical BP-based photonic devices. The possibility of generating mm-sized BP monocrystals was recently demonstrated. However, besides increasing the scarce number of 3D photonic structural materials, their applications as 3D photonic crystals do not show apparent advantages over other solid materials or metamaterials. Having a tunable BP monocrystal, where crystals could be switched, modulating simultaneously some of their properties as 3D photonic crystals, they would constitute a new family of materials with superior performance to other existing materials, opening up a plethora of new applications. In this work, an all-optical switchable 3D photonic crystal based on BPs doped with tailored photoactive molecules is demonstrated. Two switching modes have been achieved, one where the BP reversibly transitions between two BP phases, BPI and BPII, (two different cubic crystal systems) while maintaining the monocrystallinity of the whole system. The second mode, again reversible, switches between BPI and isotropic state. None of these modes are related to the regular thermal transitions between LC phases; switching is triggered by light pulses of different wavelengths. This all-optical approach allows for a seamless fast remotely controlled optical switch between two 3D photonic crystals in different cubic crystal systems and between a photonic crystal and an isotropic matrix. Applications of switchable BPs for adaptive optics systems or photonic integrated circuits would make great advances using 3D photonic crystal switches. All-optical photonic systems such as these hold great promise for the development of tunable and efficient photonic devices such as dynamic optical filters and sensors, as they enable light-driven modulation and sensing applications with unprecedented versatility.

Microstructure of the Advanced Titanium Alloy VT8M-1 Subjected to Rotary Swaging.

In this study, the microstructural behavior of the advanced Ti-5.7Al-3.8Mo-1.2Zr-1.3Sn-0.15Si (VT8M-1) alloy during rotary swaging (RS) was investigated. VT8M-1 has increased heat resistance and is considered a replacement for the Ti-6Al-4V alloy. It was shown that, during RS, the evolution of the primary a phase is characterized by the formation of predominantly low-angle boundaries according to the mechanism of continuous dynamic recrystallization. The density of low-angle boundaries increases three times: from 0.38 µm-1 to 1.21 µm-1 after RS. The process of spheroidization of the lamellar (a + b) component is incomplete. The average size of globular a and b particles was 0.3 µm (TEM). It is shown that the microstructures after RS (ε = 1.56) and equal-channel angular pressing (ECAP) (ε = 1.4) are significantly different. The temperature-velocity regime and the predominance of shear deformations during ECAP contributed to a noticeable refinement of the primary a-phase and a more complete development of globularization of the lamellar (a+b) component. EBSD studies have shown that RS leads to the formation of a structure with a higher density of low- and high-angle boundaries compared to the structure after ECAP. The results are useful for predicting alloy microstructure in the production of long rods that are further used in forging operations.

External and gastrointestinal parasites of the Franklin's Gull, Leucophaeus pipixcan (Charadriiformes: Laridae), in Talcahuano, central Chile.

Parasitological studies of the Franklin's gull, Leucophaeus pipixcan, are scarce, and knowledge about its endoparasites is quite limited. In order to describe its parasitic community, a total of 60 Franklin's gulls were captured in the coastal area in central Chile, using modified Bal-chatri traps. Ectoparasites were collected from all 60 live individuals through inspection of their plumage, while 30 were examined for endoparasites by standard parasitological necropsy. The prevalence of ectoparasites was 78.3%, including the feather mite Zachvatkinia larica (43.3%) and four species of lice: Actornithophilus piceus lari (15.0%), Austromenopon transversum (6.7%), Quadraceps punctatus (10.0%) and Saemundssonia lari (46.7%). Some 25 of 30 (83.3%) of birds necropsied were parasitized with the following helminths: Aporchis sp. (6.7%), Tetrabothrius cylindraceus (56.7%), Cyclophyllidea gen. sp. (3.3%), Profilicollis altmani (56.7%), Eucoleus contortus (10.0%), Cosmocephalus obvelatus (13.3%), Paracuaria adunca (10.0%), Stegophorus sp. (3.3%) and Tetrameres skrjabini (3.3%). To our knowledge, with the exception of P. altmani, these helminths are reported for first time in the Franklin's gull.

External and gastrointestinal parasites of the Franklin's Gull, Leucophaeus pipixcan (Charadriiformes: Laridae), in Talcahuano, central Chile / Parasitas externos e gastrointestinais da gaivota de Franklin Leucophaeus pipixcan (Charadriiformes: Laridae) em Talcahuano, Chile central

Abstract Parasitological studies of the Franklin's gull, Leucophaeus pipixcan, are scarce, and knowledge about its endoparasites is quite limited. In order to describe its parasitic community, a total of 60 Franklin's gulls were captured in the coastal area in central Chile, using modified Bal-chatri traps. Ectoparasites were collected from all 60 live individuals through inspection of their plumage, while 30 were examined for endoparasites by standard parasitological necropsy. The prevalence of ectoparasites was 78.3%, including the feather mite Zachvatkinia larica (43.3%) and four species of lice: Actornithophilus piceus lari (15.0%), Austromenopon transversum (6.7%), Quadraceps punctatus (10.0%) and Saemundssonia lari (46.7%). Some 25 of 30 (83.3%) of birds necropsied were parasitized with the following helminths: Aporchis sp. (6.7%), Tetrabothrius cylindraceus (56.7%), Cyclophyllidea gen. sp. (3.3%), Profilicollis altmani (56.7%), Eucoleus contortus (10.0%), Cosmocephalus obvelatus (13.3%), Paracuaria adunca (10.0%), Stegophorus sp. (3.3%) and Tetrameres skrjabini (3.3%). To our knowledge, with the exception of P. altmani, these helminths are reported for first time in the Franklin's gull.

Resumo Existem escassos estudos de parasitismo em gaivota-de-Franklin Leucophaeus pipixcan, e o conhecimento sobre seus endoparasitas é ainda mais limitado. Com o objetivo de descrever sua comunidade parasitaria, um total de 60 gaivotas-de-Franklin foram capturadas usando-se armadilhas Bal-chatri numa zona costeira do centro do Chile. A pesquisa de ectoparasitas foi realizada em todos os indivíduos capturados e, para os endoparasitas, foram examinados 30 deles por necropsias. A prevalência de ectoparasitas foi de 78,3%, incluíndo o ácaro de pena Zachvatkinia larica (43,3%) e outras quatro espécies de piolhos, Actornithophilus piceus lari (15,0%), Austromenopon transversum (6,7%), Quadraceps punctatus (10,0%) e Saemundssonia lari (46,7%). Das aves necropsiadas, 83,3% estavam parasitadas por helmintos, sendo registrados Aporchis sp. (6,7%), Tetrabothrius cylindraceus (56,7%), Cyclophyllidea gen. sp. (3,3%), Profilicollis altmani (56,7%), Eucoleus contortus (10,0%), Cosmocephalus obvelatus (13,3%), Paracuaria adunca (10,0%), Stegophorus sp. (3,3%) e Tetrameres skrjabini (3,3%). Com exceção de P. altmani, este é o primeiro relato desses helmintos parasitando gaivotas-de-Franklin.

Acari of Canada.

Summaries of taxonomic knowledge are provided for all acarine groups in Canada, accompanied by references to relevant publications, changes in classification at the family level since 1979, and notes on biology relevant to estimating their diversity. Nearly 3000 described species from 269 families are recorded in the country, representing a 56% increase from the 1917 species reported by Lindquist et al. (1979). An additional 42 families are known from Canada only from material identified to family- or genus-level. Of the total 311 families known in Canada, 69 are newly recorded since 1979, excluding apparent new records due solely to classification changes. This substantial progress is most evident in Oribatida and Hydrachnidia, for which many regional checklists and family-level revisions have been published. Except for recent taxonomic leaps in a few other groups, particularly of symbiotic mites (Astigmata: feather mites; Mesostigmata: Rhinonyssidae), knowledge remains limited for most other taxa, for which most species records are unpublished and may require verification. Taxonomic revisions are greatly needed for a large majority of families in Canada. Based in part on species recorded in adjacent areas of the USA and on hosts known to be present here, we conservatively estimate that nearly 10,000 species of mites occur in Canada, but the actual number could be 15,000 or more. This means that at least 70% of Canada's mite fauna is yet unrecorded. Much work also remains to match existing molecular data with species names, as less than 10% of the ~7500 Barcode Index Numbers for Canadian mites in the Barcode of Life Database are associated with named species. Understudied hosts and terrestrial and aquatic habitats require investigation across Canada to uncover new species and to clarify geographic and ecological distributions of known species.

A new species of the feather mite genus Dubininia Vassilev, 1958 (Acari: Xolalgidae) from the Black-thighed Falconet Microhierax fringillarius (Falconiformes: Falconidae).

A new feather mite species Dubininia microhieracis sp. n. (Analgoidea: Xolalgidae) is described from the Black-thighed Falconet Microhierax fringillarius (Drapiez) (Falconiformes: Falconidae) from Java. This is the second species of the genus Dubininia found on falconiform hosts; most known species of this genus are associated with parrots (Psittaciformes).

Complexity of mitochondrial dynamics in neurons and its control by ADP produced during synaptic activity.

This review focuses on different aspects of dynamics of mitochondria in neuronal cytoplasm which play an important role in the life and fate of neurons. It starts with description of the energy supply in the brain; considers the typical patterns of mitochondrial movements; relates them to the neuronal activity and in particular at the synapses; extends to the analysis of the origin of local ATP changes in the cytoplasm; considers main features of motor-assisted movements of mitochondria and their role in determining a transport velocity; describes the measurements of ATP gradients in neuronal processes and relates them to spatial variations in the mobility of mitochondria that occur in the vicinity of synapses due to the local ADP increases; considers the influence of hypoxia and intracellular signalling pathways on mitochondria movements. Finally, the recent views on the mechanisms and possible functional role of mitochondrial network as a whole in neurons are discussed and unresolved issues and future perspectives in this field of research are delineated.

Leucocytozoon hamiltoni n. sp. (Haemosporida, Leucocytozoidae) from the Bukharan great tit Parus bokharensis.

A new species of Leucocytozoon with gametocytes in fusiform host cells is described from the Bukharan great tit Parus bokharensis. It represents the first leucocytozoid in which the host cell nucleus is split into 2 more or less symmetrical portions, each located at an end of the host cell within its elongated fusiform processes. This species appears to be restricted with respect to geography and host.