Experimental bio-artificial liver:Importance of the architectural design on ammonia detoxification performance

AIM To determine the influence of the construction design over the biological component's performance in an experimental bio-artificial liver(BAL) device.METHODS Two BAL models for liver microorgans(LMOs) were constructed. First, we constructed a cylindrical BAL and tested it without the biological component to establish its correct functioning. Samples of blood and biological compartment(BC) fluid were taken after 0, 60, and 120 min of perfusion. Osmolality, hematocrit, ammonia and glucose concentrations, lactate dehydrogenase(LDH) release(as a LMO viability parameter), and oxygen consumption and ammonia metabolizing capacity(as LMO functionality parameters) were determined. CPSI and OTC gene expression and function were measured. The second BAL, a "flat bottom" model, was constructed using a 25 cm2 culture flask while maintaining all other components between the models. The BC of both BALs had the same capacity(approximately 50 cm3) and both were manipulated with the same perfusion system. The performances of the two BALs were compared to show the influence of architecture.RESULTS The cylindrical BAL showed a good exchange of fluids and metabolites between blood and the BC, reflected by the matching of osmolalities, and glucose and ammonia concentration ratios after 120 min of perfusion. No hemoconcentration was detected, the hematocrit levels remained stable during the whole study, and the minimal percentage of hemolysis(0.65% ± 0.10%) observed was due to the action of the peristaltic pump. When LMOs were used as biological component of this BAL they showed similar values to the ones obtained in a Normothermic Reoxygenation System(NRS) for almost all the parameters assayed. After 120 min, the results obtained were: LDH release(%): 14.7 ± 3.1 in the BAL and 15.5 ± 3.2 in the NRS(n = 6); oxygen consumption(μmol/min?g wet tissue): 1.16 ± 0.21 in the BAL and 0.84 ± 0.15 in the NRS(n = 6); relative expression of Cps1 and Otc: 0.63 ± 0.12 and 0.67 ± 0.20, respectively, in the BAL, and 0.86 ± 0.10 and 0.82 ± 0.07, respectively, in the NRS(n = 3); enzymatic activity of CPSI and OTC(U/g wet tissue): 3.03 ± 0.86 and 222.0 ± 23.5, respectively, in the BAL, and 3.12 ± 0.73 and 228.8 ± 32.8, respectively, in the NRS(n = 3). In spite of these similarities, LMOs as a biological component of the cylindrical BAL were not able to detoxify ammonia at a significant level(not detected vs 35.1% ± 7.0% of the initial 1 mM NH4+ dose in NRS, n = 6). Therefore, we built a second BAL with an entirely different design that offers a flat base BC. When LMOs were placed in this "flat bottom"device they were able to detoxify 49.3% ± 8.8% of the initial ammonia overload after 120 min of perfusion(n = 6), with a detoxification capacity of 13.2 ± 2.2 μmol/g wet tissue.CONCLUSION In this work, we demonstrate the importance of adapting the BAL architecture to the biological component characteristics to obtain an adequate BAL performance.

Mortality by Parasitization in the Association between <i>Diachasmimorpha tryoni</i>(Hymenoptera: Braconidae) and <i>Ceratitis capitata</i>(Diptera: Tephritidae) under Field-Cage Conditions

Ceratitis capitata (Wiedemann) is one of the major pests currently affecting world fruit production. In Argentina’s northern Citrus-producing regions, C. capitata is actively multiplying in large exotic host fruits, such as Citrus paradisi Macfadyen (grapefruit), Citrus aurantium L. (sour orange) and Citrus sinensis L. (Osbeck) (sweet orange). Faced with this situation, the use of parasitoids as biocontrol agents is currently receiving renewed attention as a new biological tool for controlling pestiferous fruit flies within the Argentinean National Fruit Fly Control and Eradication Program (ProCEM). Consequently, a viable approach to controlling C. capitata involves the use of exotic parasitoids such as Diachasmimorpha tryoni (Cameron). In this study, the effectiveness of D. tryoni females to find and successfully parasitize C. capitata larvae infesting all Citrus species mentioned earlier was assessed. Parasitoids were allowed to forage for 8 h on grapefruits and oranges artificially infested with laboratory-reared C. capitata larvae under natural environmental conditions (field cage). Parasitoid emergence, parasitism, overall effectiveness, and sex ratio of parasitoid offspring were estimated as response variables. The higher effectiveness of D. tryoni females recorded from C. sinensis would be mainly a result of both increased host density per unit of fruit surface area and fruit physical features. The study provides evidence that D. tryoni contributed to C. capitata mortality in all Citrus species assessed. However, the mortality values recorded from C. sinensis, C. aurantium, and C. paradisi did not exceed 10%, 1.5%, and 1.7%, respectively. Nonetheless, D. tryoni might be selected to forage under both high and low host density conditions.

Characterization and Comparison of Microbial Soil Diversity in Two Andean Peatlands in Different States of Conservation-Vega Tocorpuri

Cerro Tocorpuri, belongs to the II region of Chile, in San Pedro de Atacama, on the border of Chile-Bolivia. The presence of a more or less constant supply of water conditions the existence of characteristic vegetation systems known as bogs (bofedales, vegas and marshes). These wetlands have a cultural, environmental and economic social importance. As a result of the exploitation of aquatic rights, peatlands began to dry up with the consequent loss of natural resources and damage to ancestral rights, and natural resources. The activities of microorganisms in wetlands play an important role in biogeochemical processes. The interaction between microbial diversity and soil, influences to the ability of the ecosystem to recover from stress (resilience). In the present work, the soil characteristics and the associated microbial biodiversity were studied, comparing samples of active and deteriorated peatland. It was seen that the loss of water causes great changes in the physical-chemical characteristics of the soil, which leads to a modification of the microbiota Proteobacteria decreased by 18% in deteriorated peatlands, which are evident more sensible to extreme conditions while Acidobacteria, Actinobacteria increased in these sample showing a better adaptation to the change of conditions. In view of the fact that high Andean Peatlands are exposed to increasing environmental impact, this preliminary comparative study of pristine and altered soil could guide the research directed to recovery of dead peatlands strategies.

Metformin revisited: Does this regulator of AMP-activated protein kinase secondarily affect bone metabolism and prevent diabetic osteopathy?

Patients with long-term type 1 and type 2 diabetes mellitus(DM) can develop skeletal complications or "diabetic osteopathy". These include osteopenia, osteoporosis and an increased incidence of low-stress fractures. In this context, it is important to evaluate whether current anti-diabetic treatments can secondarily affect bone metabolism. Adenosine monophosphateactivated protein kinase(AMPK) modulates multiple metabolic pathways and acts as a sensor of the cellular energy status; recent evidence suggests a critical role for AMPK in bone homeostasis. In addition, AMPK activation is believed to mediate most clinical effects of the insulin-sensitizer metformin. Over the past decade, several research groups have investigated the effects of metformin on bone, providing a considerable body of pre-clinical(in vitro, ex vivo and in vivo) as well as clinical evidence for an anabolic action of metformin on bone. However, two caveats should be kept in mind when considering metformin treatment for a patient with type 2 DM at risk for diabetic osteopathy. In the first place, metformin should probably not be considered an antiosteoporotic drug; it is an insulin sensitizer with proven macrovascular benefits that can secondarily improve bone metabolism in the context of DM. Secondly, we are still awaiting the results of randomized placebo-controlled studies in humans that evaluate the effects of metformin on bone metabolism as a primary endpoint.

Rough Sets for Human Resource Competence Evaluation and Experiences

The evaluation of labor competences is an important activity for proper management of human resources. To assess labor competences, different techniques have been proposed, but these proposals represent invasive mechanisms so that its implementation affects the efficiency of the project, and do not store the experiences for further processing. The aim of this paper is to propose two alternative algorithms to recover the evidences of performance of human resources by identifying their relationship with labor competences, using rough sets and text distance. The experimental application of the algorithms demonstrated efficiency levels in line with the human evaluators and efficiency improvement in the evaluation process, compared with methods like 360 degrees.

Biological Control of <i>Ceratitis capitata</i>(Diptera: Tephritidae) in Argentina: Releases of <i>Diachasmimorpha longicaudata</i>(Hymenoptera: Braconidae) in Fruit-Producing Semi-Arid Areas of San Juan

The Mediterranean fruit fly (Medfly), Ceratitis capitata (Wiedemann) is one of the major pests of fruit crops in Argentina and it is a phytosanitary barrier to the export of fresh fruits. In the Province of San Juan, located in the central-eastern region of Argentina known as Cuyo, control strategies against Medfly in fruit-producing irrigated-valleys have been implemented by the National Fruit Fly Control and Eradication Program (ProCEM) jointly with the provincial government and the producers. This program uses an area-wide integrated pest management approach that includes the use of environment-friendly strategies to suppress or eradicate Medfly, such as the use of the sterile insect technique and the application of new-generation bait sprays, and more recently the release of the Indo-Pacific parasitoid Diachasmimorpha longicaudata (Ashmead). This exotic larval-prepupal endoparasitoid is being mass-reared on larvae of Vienna 8 TSL C. capitata strain at the BioPlanta San Juan facility. In this respect, the objective of this study was to assess the effectiveness of laboratory-reared D. longicaudata females in order to find and successfully parasitize Medfly larvae in different host fruit species once released under semi-arid environmental conditions in ecologically isolated fruit-growing valleys of San Juan. Ground releases were used to disperse parasitoids in 6 fruit-producing valleys. In total, 40,000 adult parasitoids were released at places with various Medfly host plants bearing fruits and in which no insecticides were regularly applied, such as backyards and small orchards. 119 D. longicaudata adults were recovered from 6 Medfly-infested fruit species that were collected in 5 release sites (Pocito, Zonda, Santa Lucía, Caucete, and Rivadavia). The highest number of parasitoids was recovered from fig, followed by grape, rose, orange, tangerine, and persimmon. Data provided from this study open up the possibility of implementing a parasitoid mass-release program in San Juan.

阿苯达唑对土源性蠕虫流行社区儿童遗传性过敏症患病率的影响:一项聚类随机试验

Background: Epidemiological studies have shown inverse associations between geohelminth (intestinal helminth) infection and atopy, leading to the suggestion that geohelminths might protect against allergy. Periodic deworming of school children with anthelmintics is a widely implemented intervention and has raised concerns that such programmes could increase allergy. We investigated the effect of repeated anthelmintic treatments with albendazole over 12 months on the prevalence of atopy and clinical indices of allergy. Methods: We did a cluster-randomised controlled trial in schoolchildren from 68 rural schools. Children were randomly assigned by school to either albendazole (34 schools, 1164 children) every 2 months for 12 months, or to no intervention (34 schools, 1209 children). The intervention schools received a total of seven albendazole treatments. The primary outcome was atopy at 12 months (allergen skin-test reactivity), and analysis was by intention-to-treat for whole-school analyses and per protocol for children. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN61195515. Findings: Data for analysis were available for all schools and from 67.4%(784 of 1164) and 70.1%(848 of 1209) of children in albendazole and no-treatment groups, respectively. Albendazole treatment caused large reductions in geohelminth prevalence over the study period (adjusted odds ratio 0.13, 95%CI 0.09-0.19, p < 0.001), but there was no evidence that treatment was associated with an increase in atopy prevalence (0.97, 0.68-1.39, p=0.862), or clinical allergy (wheeze, 1.07, 0.54-2.11, p=0.848) in the albendazole compared with the no-treatment group. Interpretation: We saw no increase in the prevalence of atopy or clinical allergy associated with albendazole treatment. Deworming programmes for schoolchildren are unlikely to be accompanied by an increase in allergy.

Promiscous female Euxesta eluta derive nutrients for ovarian development by expelling and consuming ejaculates

Seminal gifts range from important material donations to items that provide little direct benefit to females.Promiscuous,female silk corn flies Euxesta eluta expel and consume male ejaculates immediately after mating.The evolution and function of this peculiar behavior are currently unknown.We performed a series of experiments aimed to:determine if females under different dietary regimes derive nutrients or water for survival and/or reproduction from ejaculate consumption,if males suffer a fitness cost from supplying females with ejaculates,and if females prefer to mate and/or are more likely to store sperm from well fed than nutritionally stressed presumably inferior males.Experiments revealed that protein deprived E.eluta females derive nutrients for ovarian development through consumption of ejaculates of protein fed males.No seminal products affecting survival appear to be transferred in the consumed ejaculate.However,ovarian development,in contrast to testes growth,occurs in detriment of longevity.Females preferred to mate with protein fed males,yet sperm retention in spermathecae was extremely rare after a single mating.This finding suggests that females could be exerting post copulatory control.A key question that remained to be addressed for the understanding of this puzzling and promiscuous mating system is what ecological factors or male traits drive females to retain sperm from one or several males in order to achieve and/or maximize fertilization potential.

The endemic Patagonian vespertilionid assemblage is a depauperate ecomorphological vicariant of species-rich neotropical assemblages

Vespertilionidae is the most diverse chiropteran family, and its diversity is concentrated in warmregions of the World; however, due to physiological and behavioral adaptations, these bats alsodominate bat faunas in temperate regions. Here we performed a comparative study of vespertili-onid assemblages from two broad regions of the New World, the cold and harsh Patagonia, versusthe remaining temperate-to-subtropical, extra-Patagonian eco-regions of the South AmericanSouthern Cone. We took an ecomorphological approach and analyzed the craniodental morpho-logical structure of these assemblages within a phylogenetic framework. We measured 17 cranio-dental linear variables from 447 specimens of 22 currently recognized vespertilionid species of thestudy regions. We performed a multivariate analysis to define the morphofunctional space, andcalculated the pattern and degree of species packing for each assemblage. We assessed the im-portance of phylogeny and biogeography, and their impact on depauperate （Patagonian） versusrich （extra-Patagonian） vespertilionid assemblages as determinants of morphospace structuring.We implemented a sensitivity analysis associated to small samples of rare species. The morpho-logical patterns were determined chiefly by the evolutionary history of the family. The Patagonianassemblage can be described as a structurally similar but comparatively depauperate ecomorpho-logical version of those assemblages from neighboring extra-Patagonian eco-regions. ThePatagonian assemblage seems to have formed by successively adding populations from Northernregions that eventually speciated in the region, leaving corresponding sisters （vicariants） in extra-Patagonian eco-regions that continued to be characteristically richer. Despite being structurallyakin, degree of species packing in Patagonia was comparatively very low, which may reflect the ef-fect of limited dispersal success into a harsh region for bat survival.

Carbon pool dynamics after variable retention harvesting in Nothofagus pumilio forests of Tierra del Fuego

Background It is necessary to determine the implications for managing forest stands using variable retention harvesting for maintaining carbon and for calculating the effects of different harvesting practices on above-and below-ground carbon balance in forest ecosystems.In this context,forest carbon management has gained more attention among managers and policy-makers during recent years.The aim of this study was to determine carbon pool dynamics in different forest ecosystem components after variable retention harvesting(VRH)to characterize the ecological stability and quantify the recovery rate through the years-after-harvesting(YAH).Methods Carbon pool compartmentalization of 14 different components was determined in 60 harvested and primary unmanaged forests during the first 18 YAH in Tierra del Fuego(Argentina).We compared them using uni-and multi-variate methods,relativizing the outputs with primary unmanaged forests.Results We determined the effectiveness to retain carbon components in post-harvested stands under different retention strategies(aggregated vs.dispersed).The balance among carbon pool components changed between managed and unmanaged stands across the YAH,and was directly related to the impact magnitude.Aggregated retention improved the ecological stability of the harvested areas,where the below-ground components were more stable than the above-ground components.The recovery rate was directly related to the post-harvesting natural dynamics of the stands.The studied period was not enough to fully recover the C levels of primary unmanaged for-ests,but VRH showed advantages to increase the C pools in the managed stands.Conclusions Promoting VRH can improve sustainable forestry at the landscape level and in the long term,generating positive synergies with biodiversity and the provision of ecosystem services.This study provides important new insights into forest carbon management,in particular to setting standards in carbon projects and sets the groundwork for analysing the economics of the mentioned harvesting systems.

Effects of chlorpyrifos on enzymatic systems of Cydia pomonella （Lepidoptera： Tortricidae） adults

The control program of codling moth （Cydia pomonella L.） in the Rio Negro and Neuqu6n Valley is intended to neonate larvae. However, adults may be subjected to sublethal pesticide concentrations generating stress which might enhance both mutation rates and activity of the detoxification system. This study assessed the exposure effects of chlorpyrifos on target enzyme and, both detoxifying and antioxidant systems of surviving adults from both a laboratory susceptible strain （LSS） and a field population （FP）. The results showed that the FP was as susceptible to chlorpyrifos as the LSS and, both exhibited a similar chlorpyrifos-inhibitory concentration 50 （IC50） of acetylcholinesterase （ACHE）. The FP displayed higher carboxylesterase （CarE） and 7-ethoxycoumarine O-deethylase （ECOD） activities than LSS. Both LSS and FP showed an increase on CarE activity after the exposure to low-chlorpyrifos concentrations, followed by enzyme inhibition at higher concentrations. There were no significant differences neither in the activities of glutathione S-transferases （GST）, catalase （CAT） and superoxide dismutase （SOD） nor in the reduced glutathione （GSH） content between LSS and FP. Moreover, these enzymes were unaffected by chlorpyrifos. In conclusion, control adults from the FP exhibited higher CarE and ECOD activities than control adults from the LSS. AChE and CarE activities were the most affected by chlorpyrifos. Control strategies used for C. pomonella, such as rotations of insecticides with different modes of action, will probably delay the evolution of insecticide resistance in FPs from the study area.

Female control of sperm ejection and retention in the cornsilk fly Euxesta eluta(Diptera:Ulididae)

Promiscuous mating systems provide the opportunity for females to bias fertilization toward particular males.However,distinguishing between male sperm com-petition and active female sperm choice is difficult for species with internal fertilization.Nevertheless,species that store and use sperm of different males in different storing struc-tures and species where females are able to expel all or part of the ejaculates after cop-ulation may be able to bias fertilization.We report a series of experiments aimed at pro-viding evidence of female sperm choice in Euxesta eluta(Hendel),a species of ulidiid fly that expels and consumes ejaculates after copulation.We found no evidence of greater reproductive success for females mated singly,multiply with the same male,or mated multiply with different males.Female E.eluta possesses two spherical spermathecae and a bursa copulatrix for sperm storage,with a ventral receptacle.There was no significant difference in storing more sperm in spermathecae 24 h after copulation than immediately after copulation.Females mated with protein-fed males had greater reproductive success than similar females mated to protein-deprived males.Protein-fed females prevented to consume the ejaculate,retained more sperm when mated to protein-fed males than when mated to protein-deprived males.Our results suggest that female E.eluta can exert control of sperm retention of higher quality males through ejaculate ejection.

Male age and strain affect ejaculate quality in the Mexican fruit fly

Aging in all organisms is inevitable. Male age can have profound effects on mating success and female reproduction, yet relatively little is known on the effects of male age on different components of the ejaculate. Furthermore, in mass-reared insects used for the Sterile Insect Technique, there are often behavioral differences between mass-reared and wild males, while differences in the ejaculate have been less studied. The ejaculate in insects is composed mainly of sperm and accessory gland proteins. Here, we studied how male age and strain affected （i） protein quantity of testes and accessory glands, （ii） the biological activity of accessory gland products injected into females, （iii） sperm viability, and （iv） sperm quantity stored by females in wild and mass-reared Anastrepha ludens （Diptera： Tephritidae）. We found lower protein content in testes of old wild males and lower sperm viability in females mated with old wild males. Females stored more sperm when mated to young wild males than with young mass-reared males. Accessory gland injections of old or young males did not inhibit female remating. Knowledge of how male age affects different ejaculate components will aid our understanding on investment of the ejaculate and possible postcopulatory consequences on female behavior.

Suitable conditions for natural regeneration in variable retention harvesting of southern Patagonian Nothofagus pumilio forests

Background:Variable retention(aggregated and dispersed retention)harvesting proposed for Nothofagus pumilio was designed for timber purposes and biodiversity conservation.Harvesting by opening canopy generates different microenvironments and creates contrasting conditions for seedling establishment,growth,and eco-physiology performance due to synergies(positives or negatives)with biotic and abiotic factors.This study evaluated the regeneration in different microenvironment conditions within managed stands during 5 years after harvesting.Remnant forest structure after harvesting and different microenvironments were characterized in managed stands,where 105 regeneration plots were measured(3 stands×7 microenvironments×5 replicas).We characterized the seedling bank,as well as growth and ecophysiology performance of the regeneration.Univariate and multivariate analyses were conducted for the comparisons.Results:Microenvironments offered different environmental conditions for natural regeneration(soil moisture and light availability).Seedling under debris and dicot plants showed better eco-physiological performance,establishment,and growth than plants growing under monocots or located in the dispersed retention without the protection of other understory plants.The most unfavorable microenvironment conditions were high canopy cover of remnant trees(inside the aggregates or close to trees in the dispersed retention)and heavily impacted areas(skidder extraction roads).Conclusions:Favorable microenvironments in the harvested areas will improve the natural recruitment,growth,and eco-physiology performance of the natural regeneration after harvesting.It is necessary to develop new silvicultural practices that decrease the unfavorable microenvironments(e.g.,road density or excessive woody accumulation),to assure the success of the proposed silvicultural method.

Genetic variation in foundation species governs the dynamics of trophic interactions

Various studies have demonstrated that the foundation species genetic diversity can have direct effects that extend beyond the individual or population level, affecting the dependent communities. Additionally, these effects may be indirectly extended to higher trophic levels throughout the entire community. Quercus castanea is an oak species with characteristics of foundation species beyond pre- senting a wide geographical distribution and being a dominant element of Mexican temperate forests. In this study, we analyzed the influence of population （He） and individual （HL） genetic diversity of Q. castanea on its canopy endophagous insect community and associated parasitoids. Specifically, we studied the composition, richness （S） and density of leaf-mining moths （Lepidoptera： Tischeridae, Citheraniidae）, gall-forming wasps （Hymenoptera： Cynipidae）, and canopy parasitoids of Q. castanea. We sampled 120 trees belonging to six populations （20/site） through the previously recognized gradi- ent of genetic diversity. In total, 22 endophagous insect species belonging to three orders （Hymenoptera, Lepidoptera, and Diptera） and 20 parasitoid species belonging to 13 families were identified. In general, we observed that the individual genetic diversity of the host plant （HL） has a significant positive effect on the S and density of the canopy endophagous insect communities. In contrast, He has a significant negative effect on the S of endophagous insects. Additionally, indirect effects of HL were observed, affecting the S and density of parasitoid insects. Our results suggest that genetic variation in foundation species can be one of the most important factors governing the dynamics of tritrophic interactions that involve oaks, herbivores, and parasitoids.