Selection of a highly virulent fungal isolate, Metarhizium anisopliae CLO 53, for controlling Hoplia philanthus

The June beetle, Hoplia philanthus Füessly (Coleoptera: Scarabaeidae), has become a widespread and destructive insect pest of lawns, sport turf, pastures, and horticultural crops in Belgium. The virulence of 34 entomopathogenic fungal isolates from the genera Metarhizium, Beauveria, and Paecilomyces to third-instar H. philanthus was tested in bioassays by dipping larvae in 10(7)conidia/ml suspensions. Two isolates of Metarhizium anisopliae (CLO 53 and CLO 54) caused maximally 90% mortality 10 weeks post-inoculation while other isolates only caused mortalities between 10 and 62%. The virulence of M. anisopliae CLO 53 was further tested by exposing H. philanthus larvae to conidial serial concentrations of 10(4)-10(9)conidia/g sandy soil for up to 11 weeks at 15, 20 or 25 degrees C. Mortality was dependant on the fungal concentration, exposure time, and temperature. Eleven weeks after inoculation, the LC50 values for this isolate ranged from 1.3 to 4.0 x 10(6), 1.0 to 3.2 x 10(5), and 2.5 x 10(4) to 10(5)conidia/g soil at 15, 20, and 25 degrees C, respectively. The LT50 values for this isolate ranged from 3.5 to 21.7, 2.4 to 18.7, and 2.9 to 16.1 weeks at concentrations of 10(9) and 10(4)conidia/g soil at 15, 20, and 25 degrees C, respectively. In glasshouse pot experiment with perennial ryegrass (Lolium perenne L.), the isolate CLO 53 caused mortalities of 50 and 88% of H. philanthus larvae 10 weeks after application of 10(4) and 10(6)conidia/cm(2) soil surface, respectively. The present results suggest that the Belgian isolate CLO 53 has excellent potential for biological control of H. philanthus.     

MEK- 6318K 型血液分析仪对黄疸型肝病患者白细胞的检测

目的：探讨使用MEK-6318K血细胞分析仪时升高的胆红素对黄疸型肝病患者的白细胞结果影响程度及检测失败的原因,并提出解决方法。方法：对60例黄疸型肝病患者的标本分成两组：总胆红素在20—100umol／L范围30例,在100．1—250umol／L范围30例。均使用EDFA—K2抗凝真空采集病人静脉血2ml,分别用MEK-6318K血细胞分析仪和手工操作方法对同一标本进行血液细胞的分析测定。结果：总胆红素在20—100umol／L范围内30例患者的标本,两种方法测定白细胞结果经统计学处理P〉0．05无显著性差别;总胆红素在100．1—250umol／L范围内30例患者的标本,两种方法测定白细胞结果,经统计学处理P〈0．001有极显著性差别。结论：在使用MEK-6318K血细胞分析仪检测高黄疽标本时一定要注意白细胞结果,对报警标本,可以采用静脉血10ul测定模式,但最好采用手工操作来检测标本,这样才能为临床提供更准确结果。     

Coral disease dynamics at a subtropical location, Solitary Islands Marine Park, eastern Australia

Recent observations suggest that a spreading disease is increasingly contributing to hard coral mortality in the Solitary Islands Marine Park, NSW, Australia. This study determined coral disease prevalence and rate-of-spread through individual affected colonies and investigated the effect this epizootic had on coral populations at sites adjacent to South West Solitary Island. Quantitative data were collected between 2002 and 2004 using photographic and video methods, and visual census along radial arc belt transects. Disease similar to the reported white syndrome and white plague was apparent, spreading through hard coral species from the genera Turbinaria, Acropora, Goniastrea, Pocillopora, Stylophora and Porites. Coral disease prevalence varied between survey dates with mean prevalence increasing from 8.55% during March 2003 to 13.58% in June and declining to 7.75% in September and 6.21% during March 2004. There was a significant difference in mean prevalence between the affected species (p<0.001) and an overall difference between survey dates (p=0.001). Additionally, the rate-of-spread of coral disease through coral colonies determined using repeated, seasonal, still photographs followed similar patterns, with disease progression differing between affected species (p=0.004), and between survey dates (p<0.001). Analysis of the video-transects indicated significant difference in disease prevalence over larger spatial scales (100s of m). However, disease frequency did not vary significantly between 2002 and 2003.     

Transforming growth factor beta inhibits proliferation of somatic cells without influencing germ cell number in the chicken embryonic ovary

The gonadal development of chicken embryo is regulated by hormones and growth factors. Transforming growth factor beta (TGF-β) isoforms may play a critical role in the regulation of growth in chicken gonads. We have investigated the effect of the TGF-β isoforms on the number of germ and somatic cells in the ovary of the chicken embryo. Ovaries were obtained from chicken embryos at 9 days of incubation. They were organ-cultured for 72 h in groups treated with TGF-β1, TGF-β2, soluble betaglycan, TGF-β1 plus soluble betaglycan, or TGF-β2 plus soluble betaglycan, and untreated (control). TGF-β1 and TGF-β2 diminished the somatic cell number in the ovary of the chicken embryo at this age by inhibiting the proliferation of the somatic cells without increasing apoptosis. On the other hand, TGF-β1 and TGF-β2 did not affect the number of germ cells in the cultured ovary. The capacity of TGF-β1 and TGF-β2 to diminish the number of somatic cells in the ovary was blocked with soluble betaglycan, a natural TGF-β antagonist. However, changes in the location of germ cells within the ovary suggested that TGF-β promoted the migration of the germ cells from the ovarian cortex to the medulla. Thus, TGF-β affects germ and somatic cells in the ovary of the 9-day-old chicken embryo and inhibits the proliferation of somatic cells.This work was supported by DGAPA-UNAM (IN214403) and CONACYT (45030).     

Noise-Induced Coherence and Network Oscillations in a Reduced Bursting Model

The dynamics of the Hindmarsh-Rose (HR) model of bursting thalamic neurons is reduced to a system of two linear differential equations that retains the subthreshold resonance properties of the HR model. Introducing a reset mechanism after a threshold crossing, we turn this system into a resonant integrate-and-fire (RIF) model. Using Monte-Carlo simulations and mathematical analysis, we examine the effects of noise and the subthreshold dynamic properties of the RIF model on the occurrence of coherence resonance (CR). Synchronized burst firing occurs in a network of such model neurons with excitatory pulse-coupling. The coherence level of the network oscillations shows a stochastic resonance-like dependence on the noise level. Stochastic analysis of the equations shows that the slow recovery from the spike-induced inhibition is crucial in determining the frequencies of the CR and the subthreshold resonance in the original HR model. In this particular type of CR, the oscillation frequency strongly depends on the intrinsic time scales but changes little with the noise intensity. We give analytical quantities to describe this CR mechanism and illustrate its influence on the emerging network oscillations. We discuss the profound physiological roles this kind of CR may have in information processing in neurons possessing a subthreshold resonant frequency and in generating synchronized network oscillations with a frequency that is determined by intrinsic properties of the neurons. PACS 05.45.-a, 05.40.Ca, 87.18.Sn, 87.19     

White spot syndrome virus (WSSV) interaction with crayfish haemocytes

WSSV particles were detected in separated granular cells (GCs) and semigranular cells (SGCs) by in situ hybridisation from WSSV-infected crayfish and the prevalence of WSSV-infected GCs was 5%, whereas it was 22% in SGCs. This indicates that SGCs are more susceptible to WSSV and that this virus replicated more rapidly in SGCs than in GCs and as a result the number of SGCs gradually decreased from the blood circulation. The effect of haemocyte lysate supernatant (HLS), containing the degranulation factor (peroxinectin), phorbol 12-myristate 13-acetate (PMA), the Ca(2+) ionophore A23187 on GCs from WSSV-infected and sham-injected crayfish was studied. The results showed that the percentage of degranulated GCs of WSSV-infected crayfish treated with HLS or PMA was significantly lower than that in the control, whereas no significant difference was observed when treated with the Ca(2+) ionophore. It was previously shown that peroxinectin and PMA have a degranulation effect via intracellular signalling involving protein kinase C (PKC), whereas the Ca(2+) ionophore uses an alternative pathway. HLS treatment of GCs and SGCs from WSSV-infected crayfish results in three different morphological types: non-spread, spread and degranulated cells. The non-spread cell group from both GCs and SGCs after treatment with HLS had more WSSV positive cells than degranulated cells, when detected by in situ hybridisation. Taken together, it is reasonable to speculate that the PKC pathway might be affected during WSSV infection. Another interesting phenomenon was that GCs from non-infected crayfish exhibited melanisation, when incubated in L-15 medium, while no melanisation was found in GCs of WSSV-infected crayfish. However, the phenoloxidase activities of both sham- and WSSV-injected crayfish in HLS were the same as well as proPO expression as detected by RT-PCR. This suggests that the WSSV inhibits the proPO system upstream of phenoloxidase or simply consumes the native substrate for the enzyme so that no activity is shown. The percentage of apoptotic haemocytes in WSSV-infected crayfish was very low, but it was significantly higher than that in the sham-injected crayfish on day 3 or 5 post-infection. The TEM observation in haematopoietic cells (hpt cells) suggests that WSSV infect specific cell types in haematopoietic tissue and non-granular hpt cells seem more favourable to WSSV infection.     

Distribution of heterotrophic flagellates at the littoral of estuary of Chernaya River (Kandalaksha Bay, White Sea)

Species composition, distribution, and the character of structural changes in the heterotrophic flagellate community were studied along environmental gradients in the Chernaya River estuary. There were 99 species and forms of heterotrophic flagellates, subdivided into three groups: prevalently marine species and euryhaline species preferring biotopes either of higher or decreased salinity. The heterotrophic flagellate community of the estuary was continuously divided into two distinct variants: (1) cenosis of halophilic species, prevalently of sea forms and euryhaline species preferring biotopes of increased salinity; (2) cenosis of halophobic species with prevalence of euryhaline forms gravitating to fresh biotopes. The arbitrary and indistinct boundary between the variants of the community ran at a salinity of 9–10‰. The response of estuarine communities of heterotrophic flagellates and infusorians to variation of abiotic factors was similar and differed from response of communities of microphyto-, meiozoo-and macrozoobenthos; this implied similarity of the response mechanism to environmental factors in organisms of one level of organization.     

Gene silencing reveals a crucial role for anti-lipopolysaccharide factors from Penaeus monodon in the protection against microbial infections

Anti-lipopolysaccharide factors (ALFs) are antimicrobial peptides previously identified in various crustaceans. Out of five isoforms identified in Penaeus monodon, ALFPm3 is the best characterized, exhibits antibacterial and antifungal activities and can protect the shrimp from viral infections. Herein, the most recent identified ALFPm, called ALFPm6, is characterized for its potential role in the shrimp’s immunity. RNA interference-mediated gene silencing was used to study the function of ALFPm6 in comparison to ALFPm3. Knockdown of ALFPm3 gene led to rapid death with a cumulative shrimp mortality of 86% within 7 days, accompanied by a 12- and 50-fold higher bacterial count after 2 days in the haemolymph and hepatopancreas, respectively, compared to the control shrimp injected with GFP dsRNA. In contrast, gene silencing of ALFPm6 alone had no effect on the shrimp mortality, but led to a significant increase in the cumulative mortality and a faster mortality rate following Vibrio harveyi and white spot syndrome virus (WSSV) infections, respectively. These results support the roles of ALFPm6 and ALFPm3 in the protection of shrimp against microbial infections.     

Characterization of microsatellite loci in the black rhinoceros (Diceros bicornis) and white rhinoceros (Ceratotherium simum): their use for cross-species amplification and differentiation between the two species

As the population sizes of the black and white rhinoceroses continues to decline, more efforts are needed in multiple areas to help with the conservation efforts. One area being explored is the use of genetic diversity information to aid conservation decisions. In this study, we designed 21 microsatellite primers for white and black rhinoceroses, 16 and 17 of which amplified bands in the white and black rhinoceros, respectively. Out of these primers all 16 were polymorphic in the white rhinoceros and 12 of the 17 were polymorphic in the black rhinoceros. The mean number of alleles was 3.31 and 2.12, the expected heterozygosities were 0.420 and 0.372, and the observed heterozygosities were 0.436 and 0.322 for the white and black rhinoceroses, respectively. Seven of the primers produced different allele sizes and variations that distinguished between black and white rhinoceroses. Further genetic analyses with larger wild population sample sizes and markers are recommended to obtain a better understanding of the genetic structure of the black and white rhinoceros populations in order to be useful in the conservation efforts of these critically endangered species. A. Kilbourn—In memoriam.