Bark beetle community structure under four ponderosa pine forest stand conditions in northern Arizona

We studied the bark beetle guild (Coleoptera: Scolytidae) in the ponderosa pine forests of northern Arizona to explore if the species assemblages and relative abundance differ between managed and unmanaged stands. Four stand conditions were assessed: (1) unmanaged stands with high tree density, (2) thinned stands, (3) thinned and burned (with prescribed fire) stands and (4) stands that had been burned by stand replacing wildfires. The study was conducted in the ponderosa pine forests of the Coconino Plateau, northern Arizona. For several decades this area has been relatively free of bark beetle outbreaks despite the current overstocked condition of many stands. We found that a similar species assemblage composed of Dendroctonus frontalis, D. brevicomis, D. valens, D. approximatus, D. ponderosae, and Ips pini occurred across all four stand conditions over 3 years of study. The population levels of all these species were endemic across all stand conditions. The non-aggressive D. approximatus and D. valens were indicator species for thinned and unmanaged stands, respectively, but this was not consistent among years. The ambrosia beetle Gnathotrichus sp. and the bark beetle predator Enoclerus sp. consistently indicated stands burned by wildfire. In addition to our field experiment, we analyzed the historical pattern of attacks of bark beetles in our area of study. Our findings suggest that the pattern of attack of D. brevicomis (the only Dendroctonus species for which attacks have been reported) and Ips spp. has been through scattered small infestations in groups of 1–10 trees. Whereas small infestations by Ips spp. are increasing, those for D. brevicomis are decreasing. Although we agree that the high density stands in northern Arizona are in an “unhealthy” condition, our results do not show that they were supporting large bark beetle outbreaks. Our results challenge the theoretical assumptions about the relationship between stand structure, tree resistance and bark beetle performance.     

Supercritical fluid extraction of all-trans-lycopene from tomato

A procedure is proposed for the supercritical fluid extraction of all-trans-lycopene from tomato using carbon dioxide at 40 degrees C without modifier. The present method minimizes the risk of degradation via isomerization and oxidation of health-promoting ingredients, such as lycopene. The effect of different experimental variables on the solvating power of the supercritical fluid was evaluated in terms of both the selectivity achievable in the process and the yield of the extraction of all-trans-lycopene. Satisfactory separations of the all-trans-lycopene isomers from the cis counterparts were achieved using a C(30) column. The obtained extract contained 88% all-trans-lycopene and 12% cis-lycopene.     

Reshaping forest management in southern Patagonia: a qualitative assessment

Abstract

The intensive forest use has caused a significant transformation around the world. Sustainable forest management (SFM) has emerged as an alternative to address concerns regarding resource use, conservation, and socioeconomic benefits. Evidence suggests that its application remains inconsistent. In Argentina, the national government passed a law addressing management aiming to provide guidelines and incentives to steer practices into a sustainable framework. The objectives were: (a) understand what the concept of SFM means to participants in Tierra del Fuego; (b) identify and assess how different factors influence the adoption of SFM; (c) review the stakeholder perceptions on recent regulatory changes; and (d) identify the steps required for improving management. We conducted 52 semi-structured interviews with stakeholders and parties at the national level. New regulatory arrangements were implemented for a short-time before this research was undertaken, and we could not evaluate the success of reform. The study provided deep insight into the policy-making process, and the views held by different stakeholders. The historical mismanagement of the resource, together with an unfavorable past relationship with authorities, has promoted short-term perspectives which resulted in behaviors inconsistent with SFM. Moreover, the characteristic demographic composition brings a social component not identified in the broader literature as relevant for SFM adoption.     

Natural Enemies of the Frankliniella Complex Species (Thysanoptera: Thripidae) in Ataulfo Mango Agroecosystems

A field survey was conducted in Ataulfo mango (Mangifera indica L.) orchards in Chiapas, Mexico, with the objective of determining the natural enemies of the Frankliniella complex species (Thysanoptera: Thripidae). Seven species of this genus feed and reproduce in large numbers during the mango flowering. Two representative orchards were selected: the orchard “Tres A” characterized by an intensive use of agrochemicals directed against thrips, and the orchard “La Escondida” that did not spray insecticides. During mango flowering, five inflorescences were randomly collected every 5 d in both orchards, for a total of 18 sampling dates. Results revealed the presence of 18 species of arthropods that were found predating on Frankliniella. There were 11 species in the families Aeolothripidae, Phlaeothripidae, Formicidae, Anthocoridae and Chrysopidae; and seven species of spiders in the families Araneidae, Tetragnathidae, and Uloboridae. Over 88% of predators were anthocorids, including, Paratriphleps sp. (Champion), Orius insidiosus (Say), Orius tristicolor (White), and O. perpunctatus (Reuter). The orchard that did not spray insecticides had a significantly higher number of predators suggesting a negative effect of the insecticides on the abundance of these organisms.     

尼加拉瓜废弃农田次生演替后的土壤种子库

定量分析了被废弃4年、9年和14年的农田地上派生的次生林土壤中种子组成和密度,从而检测在次生林演替形成过程中,土壤种子库是否能随着植物种群的集成而集成。分别在废弃了4年、9年和14年的农田地里（15cm×15cm样方、9cm土层深）,掘取了18,37和48份土壤样品。在废弃了4,9和14年的农田地上,分别发现了3,5和9个物种。在这些不同的生命形态中,在9年和14年的迹地上,土壤种子树木占主要成分,分别为60%和33%,而4年废弃迹地主要被非木本植物所占领。三块废弃地里,4年废弃迹地植物种子的总数为327粒,相应可发育的种子密度为141粒/m2,14年废弃迹地种子的总数为46粒,相应的可发育种子的密度为26粒/m^2,指明种子数、种子密度随废弃地龄成下降趋势。在9年和14年龄废弃地上,土壤种子植物种类与立地木本植物种类的相似度较低,而4年龄地上两者比较则完全不同。我们认为：土壤种子库的物种构成是在次生演替过程中逐渐形成的,但是,所获得的总体种子密度太低,仅仅依赖于这些种子来实现树木自然再生是不可靠的。为了加快这些废弃地次生林的恢复,既要依靠自然集成的土壤种子库,还需要通过直播、所需物种的强化种植和设定人工生长环境以利于种子传播。     

Anti HSV-1 Activity of Halistanol Sulfate and Halistanol Sulfate C Isolated from Brazilian Marine Sponge Petromica citrina (Demospongiae)

The n-butanol fraction (BF) obtained from the crude extract of the marine sponge Petromica citrina, the halistanol-enriched fraction (TSH fraction), and the isolated compounds halistanol sulfate (1) and halistanol sulfate C (2), were evaluated for their inhibitory effects on the replication of the Herpes Simplex Virus type 1 (HSV-1, KOS strain) by the viral plaque number reduction assay. The TSH fraction was the most effective against HSV-1 replication (SI = 15.33), whereas compounds 1 (SI = 2.46) and 2 (SI = 1.95) were less active. The most active fraction and these compounds were also assayed to determine the viral multiplication step(s) upon which they act as well as their potential synergistic effects. The anti-HSV-1 activity detected was mediated by the inhibition of virus attachment and by the penetration into Vero cells, the virucidal effect on virus particles, and by the impairment in levels of ICP27 and gD proteins of HSV-1. In summary, these results suggest that the anti-HSV-1 activity of TSH fraction detected is possibly related to the synergic effects of compounds 1 and 2.     

Antiradical Capacity and Induction of Apoptosis on HeLa Cells by a <Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> Extract

Jamapa bean is a black Phaseolus vulgaris variety rich in condensed tannins, anthocyanins and flavonols with interesting biological activities. The objective of this work was to evaluate the antiradical capacity (ARC) of a Jamapa bean methanolic extract (BME) and some of the proanthocyanidin-rich fractions derived from it, using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The effect of the BME on some proteins involved in apoptosis on HeLa cells was also evaluated. A strong correlation between proanthocyanidin concentration in BME and antiradical capacity was found, suggesting that these compounds contribute significantly to antiradical activity. BME was a better radical scavenger than butylated hydroxytoluene (45.6 and 33.9% ARC at 400 μM, respectively). Two proanthocyanidin-rich fractions obtained after a preliminary separation of the BME using Toyopearl (TP4 and TP6) exhibited a higher antiradical activity than the parent extract. The treatment of HeLa cells with 35 μg BME/ml/24 h increased the expression of Bax and Caspase-3, pro-apoptotic proteins (6.13 and 1.2 times for Caspase-3 and Bax, respectively). The mechanism of action of some proteins involved in apoptosis was also evaluated, and the results suggest that black Jamapa bean could be an important source of polyphenolic compounds with potential biological use as antioxidant and anticancer agents.     

Clinical evaluation of gemcitabine in dogs with spontaneously occurring malignancies

We conducted a clinical evaluation of gemcitabine in 19 dogs with spontaneously occurring malignancies. The principal objectives of this study were to characterize toxicity and seek preliminary evidence of antitumor activity of gemcitabine administered every 2 weeks (biweekly) as a 30-minute IV infusion. A total of 64 doses, ranging from 300 mg/m2 to 675 mg/m2, were administered during the initial 8-week evaluation period, and an additional 131 doses were administered during the extended evaluation period. The total cumulative dose for the 10 dogs receiving gemcitabine in the extended evaluation period ranged from 1,500 mg/m2 to 24,300 mg/m2. Clinical evidence of toxicity was minimal. Cumulative myelosuppression was not apparent. Unexplained retinal hemorrhages occurred in 1 dog. No complete or partial remissions were observed during the initial evaluation period; however, objective responses were observed in 2 dogs during the extended evaluation period. Gemcitabine is a promising new chemotherapeutic agent that can be used safely in dogs with cancer. Biweekly administration of doses of 675 mg/m2 IV results in minimal and acceptable toxicity.     

Experimental infection with avian leukosis virus isolated from Marek's disease vaccines

Recently, avian leukosis virus (ALV) was isolated from four lots of Marek's disease vaccine produced by two laboratories. The ALVs isolated were characterized by examination of their interactions with cells of two phenotypes (C/E and C/A,E), subgroup-specific polymerase chain reaction (PCR), virus neutralization, envelope gene sequencing, and phylogenetic analysis. All four ALVs are exogenous, belong to subgroup A, and appear to be virtually identical to each other based on PCR and envelope gene nucleotide sequences. We describe herein the characterization of the contaminant viruses in vivo by means of experimental infection in chickens. The contaminant viruses established transient viremia in specified pathogen-free (SPF) Leghorn chickens and elicited a robust and lasting antibody response detectable by enzyme-linked immunosorbent assay. None of the contaminant ALVs induced tumors up to 31 wk of age, and mortality was insignificant. Despite a strong antibody response against the contaminant ALVs, vertical (congenital) transmission to the progeny of experimentally infected SPF chickens took place, albeit at a very low rate (< or = 1.6%). Experimental infection in meat-type chicken embryos resulted in viremia at hatch, suggesting that some meat-type chickens are susceptible to infection and support virus replication.