ABSTRACT Growing evidence suggests that parasite-infected prey is more vulnerable to predation. However, the mechanism underlying this phenomenon is obscure. In small mammals, analgesia induced by environmental stressors is a fundamental component of the defensive repertoire, promoting defensive responses. Thus, the reduced analgesia may impair the defensive ability of prey and increase their predation risk. This study aimed to determine whether coccidia infection increases the vulnerability to predation in root voles, Microtus oeconomus (Pallas, 1776), by decreased analgesia. Herein, a predator stimulus and parasitic infection were simulated in the laboratory via a two-level factorial experiment, then, the vole nociceptive responses to an aversive thermal stimulus were evaluated. Further, a field experiment was performed to determine the overwinter survival of voles with different nociceptive responses via repeated live trapping. The coccidia-infected voles demonstrated reduced predator-induced analgesia following exposure to predator odor. Meanwhile, pain-sensitive voles had lower overwinter survival than pain-inhibited voles in enclosed populations throughout the duration of the experiment. Our findings suggest that coccidia infection attenuates predator-induced analgesia, resulting in an increased vulnerability to predation.

El depósito cuprífero de Fenghuangshan, en el área de Tongling, provincia de Anhui, China, está genéticamente asociado con la granodiorita de Fenghuangshan, que contiene anfíboles que pueden ser usados para determinar la presión y la temperatura histórica de los magmas que formaron esta intrusión. En este trabajo se investigo la petrografía y la mineralogía de la granodiorita de Fenghuangshan enfocados en las variaciones de composición de anfíboles y en determinar las condiciones de cristalización de estos. Los datos se utilizaron para determinar la historia petrogenética y la significación metalogénica de la granodiorita anfitriona. Los anfíboles al interior de la intrusión pueden dividirse por texturas en fenocristales, cristales en matriz y cristales moteados. Los análisis de microsonda electrónica indican que los anfíboles son de características magnesiohornblenda y tschermakita. Las plagioclasas en la granodiorita son andesinas y oligoclasas. La barometría del aluminio en los anfíboles y la termometría de los anfíboles plagioclásticos indican que los anfíboles moteados cristalizados se fundieron a presiones entre 4,46 y 4,74 kbar y temperaturas de 1066 °C y 1071 °C, y los anfíboles en la matriz se formaron bajo condiciones de 1,00-1,91 kbar y 784-823 °C. Los datos indican que el magma que formó la granodiorita fue generado dentro del manto superior y migró a través de fracturas antes de ubicarse en la corteza media-baja a una profundidad de ∼15 km, lo que formó una profunda cámara magmática donde el magma sufrió una cristalización y asimilación fraccionada. El magma migró luego a través de estructuras geológicas (como fallas y fracturas) antes de ubicarse en la corteza a poca profundidad, entre 3 y 6 km, y formando eventualmente la granodiorita Fenghuangshan. Este modelo combinado con la barimetría, la termometría y con la estratigrafía del área de estudio indica que el depósito cuprífero de Fenghuangshan no ha experimentado cambios sustanciales desde su formación, lo que indica que tanto la granodiorita como la mineralización asociada están bien preservadas. Esta condición también nos sugiere que la profundidad final de la ubicación del magma (3-6 km) representa la profundidad de formación del depósito cuprífero asociado. Esta inferencia, combinada con el hecho de que la actual exploración y explotación en el área de estudio es de <1 km, señala que el gran potencial para descubrir mineralización cuprífera con una exploración profunda en el área.

The Fenghuangshan copper deposit, in the Tongling area of Anhui Province, China, is genetically associated with the Fenghuangshan granodiorite, which contains amphiboles that can be used to determine the pressure and temperature history of the magmas that formed this intrusion. Here, we investigate the petrography and mineralogy of the Fenghuangshan granodiorite, focusing on variations in amphibole composition and determining the conditions of amphibole crystallization. The data are used to determine the petrogenetic history and metallogenic significance of the hosting granodiorite. The amphiboles within the intrusion can be divided by texture into phenocryst, matrix, and poikilocrystal amphiboles. Electro model, combined with the barometry and thermometry and the stratigraphy of the study area, indicates that the Fenghuangshan copper deposit has not undergone any significant changes since its formation, thereby indicating that both the granodiorite and the associated mineralization are well preserved. This also suggests that the final depth of emplacement of the magma (3-6 km) represents the depth of formation of the associated copper deposit. This inference, combined with the fact that the current depth of exploration and mining in the study area is <1 km, indicates the great potential for discovering significant copper mineralization by deep exploration in this area.

Microbial lipids, which are also known as single cell oils (SCO), are produced by oleaginous microorganisms including oleaginous bacteria, yeast, fungus and algae through converting carbohydrates into lipids under certain conditions. Due to its unique environment having extremely low temperature and anoxia, the Tibetan Plateau is amongst the regions with numerous rare ecotypes such as arid desert, salt marsh, alpine permafrost, hot spring, and lawn. By using a rapid, convenient screening method, we identified 31 strains of oleaginous microorganisms from different habitats in the Tibetan Plateau, which include wetlands, lawn, hot spring, alpine permafrost, and saline-alkali soil. Molecular identity analysis showed that they belong to 15 different species, 7 of which are reported for the first time as lipid-producing microorganisms, that is, Cladosporium sp., Gibberella fujikuro, Ochrobactrum sp., Plectosphaerella sp., Tilletiopsis albescens, Backusella ctenidia, and Davidiella tassiana. The distribution of the oleaginous microorganisms varies with habitats. 11 strains were found in hot spring (35.5%), 10 in farmland (32.3%), 6 in lawn (19.4%), 2 in sand (6.4%), 1 in wetland (3.2%), and 1 in permafrost (3.2%). Carbon utilization analysis indicated that most of these filamentous fungi can use xylose and carboxymethyl cellulose (CMC) as carbon source, where Backusella ctenidia, Fusarium sp. and Gibberella fujikuroi have the strongest capability.

The analysis of individual gene product should enable to clarify the role of a particular enzyme in a complex xylanase system of A. niger. The two genes encoding precursors of co-produced endo-1,4-β-D-xylanases, xynA1 and xynB, were isolated from Aspergillus niger SCTCC 400264 (SCTCC, China) by using RT-PCR technique and then successfully expressed in Escherichia coli BL21. The nucleotide sequences of the xynA1 and xynB genes revealed that they were only 52.5% homology to each other. Characterization of the recombinant enzymes revealed the different properties: the specific activity of recombinant XYNA1 was 16.58 U/mg compared to 1201.7 U/mg for recombinant XYNB; The optimum temperature and pH of the recombinant XYNA1 were 35 ºC and 3.0, respectively, whereas the corresponding values for the recombinant XYNB were 55 ºC and 5.0, respectively; The recombinant XYNB showed much more thermostability than recombinant XYNA1; The recombinant XYNB showed 94% of maximal activity after incubating in water for 60 min at 60 ºC compared to no activity for recombinant XYNA1. Various metal ions had different effects on activity between the two recombinant xylanases.