Do investors react differently? Evidence from hospitality sector during the covid-19 pandemic.

Focusing on publicly traded U.S. eating & dining and lodging firms from 01July2019 to 30October2020, this paper examines investor reaction to restaurant and hotel firms throughout the Covid-19 pandemic. Results show that there is no consensus on buying or selling shares of different hospitality firms in the beginning. Consistent with the behavioral theory, the market reaction is mainly negative to restaurant firms matching with investors' negative sentiments while investors are indifferent towards lodging firms. In later stages, investors trade less stocks, and the buy pressure in the market leads to a positive reaction to both types of firms.

Ophryocystis sitonae sp. nov., (Neogregarinida: Ophryocystidae) parasitizing Sitona humeralis Stephens, 1831 (Coleoptera: Curculionidae).

Sitona humeralis Stephens 1831 (Coleoptera: Curculionidae) is an important pest of the Medicago and Vicia species in Turkey, and this study was conducted the determine the natural pathogens of this beetle. In the present study, a new neogregarine was observed in Malpighian tubules of the S. humeralis, collected from Ordu (Turkey) on the wild Medicago species. The yellowish oocysts were the most notable feature of the current neogregarine. The Giemsa-stained mature oocysts were fusiform shaped and measured 8.7 ± 0.7 (7.12-11.11) µm in length and 4.1 ± 0.3 (3.05-5.01) µm in width. The smooth oocyst wall was relatively thin (175-230 nm), and polar plugs were non-evident (weight = 380 nm, height = 500 nm). The 18S rDNA gene of the current neogregarine was sequenced and compared with fifteen sequences from GenBank. Morphological, ultrastructural, and molecular features indicate that the described neogregarine in S. humeralis differed from the all known Ophryocystis species and named here Ophryocystis sitonae sp. nov.

First record and distribution of Adelina sp. (Coccidia: Adeleidae) in populations of the Anisoplia segetum Herbst (Coleoptera: Scarabaeidae) in Turkey.

In this study, an Adelina sp. (Coccidia) infection was determined for the first time from Anisoplia segetum (Coleoptera: Scarabaeidae). The infection was observed in the gut and fat body of the host. The determined oocysts were ellipsoidal and measured 36.3 (34-38) × 30.2 (27-32) µm. The number of sporocysts per oocyst varied from 7 to 15. The dizoic sporocysts were usually subspherical, 10.2 (9-12) × 8.9 (8-10) µm. Also, some developmental stages and unsporulated oocysts were determined with electron microscopical observations. The immature microgamonts were observed in different shapes, from ovoid to spherical. And the detected oval unsporulated oocyst was measured 4.9 µm in length and 3.6 µm in width. The formation and distribution of these pathogens were also presented in A. segetum populations.

A new isolate of Nosema fumiferanae (Microsporidia: Nosematidae) from the date moth Apomyelois (Ectomyelois) ceratoniae, Zeller, 1839 (Lepidoptera: Pyralidae).

In this study, a microsporidian pathogen of the date moth (Apomyelois (Ectomyelois) ceratoniae, Zeller, 1839) also known as the carob moth, is described based on light microscopy, ultrastructural characteristics and comparative molecular analysis. The pathogen infects the gut and hemolymph of A. ceratoniae. All development stages are in direct contact with the host cell cytoplasm. Fresh spores with nuclei arranged in a diplokaryon are oval and measured 3.29 ± 0.23 µm (4.18-3.03 µm, n = 200) in length and 1.91 ± 0.23 µm (2.98-1.66 µm, n = 200) in width. Spores stained with Giemsa's stain measured 3.11 ± 0.31 µm (3.72-2.41 µm, n = 150) in length and 1.76 ± 0.23 µm (2.16-1.25 µm, n = 150) in width. Spores have an isofilar polar filament with 10-12 coils. An 1110 bp long alignment of the current microsporidium showed an SSU rRNA gene difference of only 0.0009, corresponding to >99.91% sequence similarity with Nosema fumiferanae, while RPB1 gene sequences were 98.03% similar within an alignment of 969 bp. All morphological, ultrastructural and molecular features indicate that the microsporidian pathogen of A. ceratoniae is the new isolate of the N. fumiferanae and is named here as Nosema fumiferanae TY61.

Structure and Magnetism of Co2Ge Nanoparticles.

The structural and magnetic properties of Co2Ge nanoparticles (NPs) prepared by the cluster-beam deposition (CBD) technique have been investigated. As-made particles with an average size of 5.5 nm exhibit a mixture of hexagonal and orthorhombic crystal structures. Thermomagnetic measurements showed that the as-made particles are superparamagnetic at room temperature with a blocking temperature (TB) of 20 K. When the particles are annealed at 823 K for 12 h, their size is increased to 13 nm and they develop a new orthorhombic crystal structure, with a Curie temperature (TC) of 815 K. This is drastically different from bulk, which are ferromagnetic at cryogenic temperatures only. X-ray diffraction (XRD) measurements suggest the formation of a new Co-rich orthorhombic phase (OP) with slightly increased c/a ratio in the annealed particles and this is believed to be the reason for the drastic change in their magnetic properties.

Structure and Magnetism of Mn5Ge3 Nanoparticles.

In this work, we investigated the magnetic and structural properties of isolated Mn5Ge3 nanoparticles prepared by the cluster-beam deposition technique. Particles with sizes between 7.2 and 12.6 nm were produced by varying the argon pressure and power in the cluster gun. X-ray diffraction (XRD)and selected area diffraction (SAD) measurements show that the nanoparticles crystallize in the hexagonal Mn5Si3-type crystal structure, which is also the structure of bulk Mn5Ge3. The temperature dependence of the magnetization shows that the as-made particles are ferromagnetic at room temperature and have slightly different Curie temperatures. Hysteresis-loop measurements show that the saturation magnetization of the nanoparticles increases significantly with particle size, varying from 31 kA/m to 172 kA/m when the particle size increases from 7.2 to 12.6 nm. The magnetocrystalline anisotropy constant K at 50 K, determined by fitting the high-field magnetization data to the law of approach to saturation, also increases with particle size, from 0.4 × 105 J/m³ to 2.9 × 105 J/m³ for the respective sizes. This trend is mirrored by the coercivity at 50 K, which increases from 0.04 T to 0.13 T. A possible explanation for the magnetization trend is a radial Ge concentration gradient.

Aranciocystis muskarensis n. gen., n. sp., a neogregarine pathogen of the Anisoplia segetum Herbst (Coleoptera: Scarabaeidae).

In this study, a new genus and species of neogregarine which is a pathogen of Anisoplia segetum Herbst (Coleoptera: Scarabaeidae), is described. The adult beetles of A. segetum were collected from Nevsehir, Turkey and neogregarine infection rates were determined as 18.52%. The Giemsa-stained mature oocysts are lemon-shaped and measured 9.34±0.82µm in length and 5.77±0.77µm in width. The oocyst wall surface of the mature oocysts is similar to an osage orange (tuberculate). Morphological, ultrastructural and molecular features indicate that the previously undescribed neogregarine is dissimilar to all known neogregarine taxa and represents the first record from Anisoplia segetum and is named here as Aranciocystis muskarensis n. gen., n. sp.

Distribution of Nosema phyllotretae (Microspora, Nosematidae) Weiser, 1961 in populations of Phyllotreta atra (Coleoptera, Chrysomelidae) in Turkey.

The distribution of Nosema phyllotretae infection of Phyllotreta atra populations in Turkey is reported for the first time. In total, 48 of the 1668 beetles from 24 samples collected in five localities were infected by the parasite. Nosema infection was found in P. atra adults from only one of the five localities studied. The infection average was 2.8% and it reached 42.5% in some samples. The results showed that N. phyllotretae infection occurs in P. atra populations in restricted localities within Turkey.

First record of the insect pathogenic alga Helicosporidium sp. (Chlorophyta: Trebouxiophyceae) infection in larvae and pupae of Rhizophagusgrandis Gyll. (Coleoptera, Rhizophaginae) from Turkey.

The predator beetle Rhizophagus grandis Gyll. (Coleoptera, Rhizophaginae) is one of the most important biological control agents, mass-bred and used to suppress populations of an important pest: the great spruce bark beetle, Dendroctonus micans. The achlorophyllous alga Helicosporidium sp. was first discovered in the pest. Later it was also found in the predator, but only in the adults. In this study, the pathogenic alga Helicosporidium sp. was discovered in larvae and early pupae of R. grandis for the first time. The morphological characteristics of the pathogenic alga were revealed by light and electron microscopy. Infection rates of Helicosporidium sp. in the larvae and pupae of R. grandis were 23.5% and 6.25%, respectively.

Parasites of Phyllotreta atra (Fabricius, 1775) (Coleoptera: Chrysomelidae) in Trabzon.

In this study, the parasites of Pyllotreta atra (Coleoptera: Chrysomelidae) in Trabzon were investigated. Samples of P. atra were collected in different localities of Trabzon. Three different types of parasites from P. atra observed are as follows: Gre-garine (Apicomplexa), Nematode (Tylenchida: Allantonematidae) and larvae of certain parasitoids. The most abundant infection found in this study was gregarine infection followed by nematode infection with total infection rates 37.8% and 7.6%, respectively. The gre-garine and the nematode parasites were identified as Gregarina phyllotretae and Howardula phyllotretae, respectively.