Atmospheric Pollution in a Tropical Rain Forest: Effects of Deposition Upon Biosphere and Hydrosphere I. Concentrations of Chemicals

The effects of atmospheric deposition upon elementcycling and turnover in three rain forest ecosystems ofthe Serra do Mar, a mountain range along the atlanticcoast of Brazil, have been investigated as part of aninterdisciplinary German-Brazilian research project ondispersion, transformation and deposition of airpollutants in the vicinity the industrial complex ofCubatão, State of São Paulo. The projectincluded on-site measurements from 1991 to 1995, fieldexperiments and mathematical modelling with the goalof providing damage evaluation and risk assessment,and elucidating damage mechanisms with respect tosoils and vegetation. The role of the `Soil Module'sub-project reported here was to assess atmosphericdeposition and fluxes with precipitation and soilwater, and to investigate possible soil changesinduced by atmospheric deposition as well asbiological effects of pollutants via the soil path.Part I of this paper deals with concentrations ofchemicals in precipitation, soil water, surface waterand in litter. Part II will cover fluxes of chemicalsand element budgets.Three sites were chosen which differed significantlywith respect to pollution impact. Annual averages ofionic concentrations in precipitation found in openfield and below the tree canopy amounted to 5 and10 mg L<sup>-1</sup>, respectively, for sulfate-S, 0.4 and0.7 mg L<sup>-1</sup> for nitrate, 0.65 and 1.1 mg L<sup>-1</sup> for fluoride,1.8 and 2.6 mg L<sup>-1</sup> for ammonium-N, 0.76 and 2.3 mg L<sup>-1</sup>for Mg, and 3.5 and 7.5 mg L<sup>-1</sup> for Ca at the mostpolluted site. The relatively `clean' reference siteattained 1/3 to 1/9 of these averages, thus clearlyreflecting the difference in air pollution load.Chemical composition in the liquid phase is completelychanged when precipitation infiltrates the soilprofile. Nitrate concentration increases by the factor5 to 20. A clear increase is also found for sulfateand chloride. Concentration changes during ecosystempassage of seepage are interpreted in relation tochemical reactions taking place in differentcompartments. They are characterized by an almostcomplete retention of ammonium and some retention ofsulfate in the upper soil layers, and at the mostpolluted site by mobilization of Al from soil mineralsand very high leaching of nitrate as a consequence ofnitirification of organic matter.     

导入LPAAT和KCS基因对油菜种子芥酸含量的影响

采用农杆菌介导法,以下胚轴为转化受体,将溶血性磷脂酸酰基转移酶（LPAAT）和酮脂酰辅酶A合成酶（KCS）基因导入2种不同基因型（“Drakkar”和“Maplus”）的甘蓝型油菜,共获得247株再生植株,其再生频率分别为15.1%和2.0%。PCR检测和Southern杂交分析证实,外源基因已整合到油菜基因组中,转化频率分别为3.6%和0.7%。种子中芥酸含量因外源基因的导入使零芥酸油菜“Drakkar”提高到10.5%,高芥酸品种“Maplus”提高了5.0%,最高达62.8%。     

A pre- and post-intervention study of infection control in equine hospitals in Sweden

Background

Detection of nosocomial methicillin-resistant Staphylococcus aureus infections in horses in Sweden has increased attention on infection control (IC) in equine hospitals. This study established baseline data on IC programmes within such settings, evaluated compliance with some IC procedures before and after an education intervention, and examined barriers to compliance.The study was carried out between 2008 and 2011 in four Swedish equine hospitals. Data on current IC of each hospital, purchase data on hand sanitisers and disposable gloves per patient, and direct observations of compliance with procedures were monitored pre- and post-intervention. The intervention comprised a lecture on common IC and a review of each hospital’s current procedures. For comparison, retrospective purchase data were reviewed. A questionnaire on individual compliance, experiences and opinions of IC was issued to employees.

Results

Three hospitals completed the study, while the fourth reported its IC procedures and completed the questionnaire. Actual numbers of procedures, content and level of documentation differed among the hospitals. Similarities were poor or absent IC implementation strategy, lack of active surveillance of compliance with procedures and no monitoring of such as nosocomial infections. Among the hospitals which completed the study, two reported pre-intervention observation of compliance, while all three reported post-intervention observations. The purchase data showed trends for changes over time, although not uniformly related to the intervention. One hospital demonstrated a significant post-intervention increase in compliance with glove procedures, accompanied by a non-significant post-intervention increase in purchases figures. Compliance with dress code and personal appearance was high in all three hospitals (92-100%), while compliance with hand hygiene procedures was generally poorer. Barriers to compliance cited in the questionnaire (data from four hospitals) included insufficient supplies of hygiene products, lack of readily accessible places for cleaning, insufficient knowledge and high workload.

Conclusions

Potential for easily attainable improvements in IC, such as traceability of documents, implementation strategies and surveillance of efficacy, was revealed. Attention to hand hygiene implementation and improvement of logistics appeared important. Data on purchases per patient were readily available and therefore applicable for intra-hospital surveillance of IC trends over time.     

Fatty acid profile of plasma,muscle and adipose tissues in Chilota lambs grazing on two different low quality pasture types in Chiloé Archipelago (Chile)

There is no information about the effect of different pasture types on tissue fatty acid profiles of a native rustic lamb breed of the Chiloe Archipelago, the Chilota. Eight Chilota lambs were grazed on a ‘Calafatal’ pasture (CP), a typical secondary succession of Chiloé Archipelago (Chile) and eight Chilota lambs were located to graze on naturalized pasture (NP) of Chiloé. Botanical, chemical and lipid composition of the two types of pastures and of different lamb tissues (muscle, subcutaneous – and tail adipose tissues) and plasma were performed. Both pasture types induced high n‐3 polyunsaturated fatty acids (PUFA) and CLAcis‐9,trans‐11 proportions in Chilota meat. Thus, in muscle, Chilota lambs grazing CP showed higher sum PUFA, sum n‐6 PUFA proportion and n‐6/n‐3 PUFA ratio compared with Chilota lambs grazing NP. In tail fats of Chilota lambs grazing CP significantly higher proportions of 18:3n‐3, sum saturated fatty acids, sum PUFA, n‐3 and n‐6 PUFA were detected compared with Chilota lambs grazing NP. Feeding of different pasture types (CP vs. NP) caused significant differences in fatty acid composition of muscle and the two fat depots in Chilota lambs, but also point to tissue‐specific responses of de novo synthesized fatty acid deposition in the tissues.     

Minimum infusion rate of alfaxalone for total intravenous anaesthesia after sedation with acepromazine or medetomidine in cats undergoing ovariohysterectomy

ObjectiveTo determine the induction doses, then minimum infusion rates of alfaxalone for total intravenous anaesthesia (TIVA), and subsequent, cardiopulmonary effects, recovery characteristics and alfaxalone plasma concentrations in cats undergoing ovariohysterectomy after premedication with butorphanol-acepromazine or butorphanol-medetomidine.Study designProspective randomized blinded clinical study.AnimalsTwenty-eight healthy cats.MethodsCats undergoing ovariohysterectomy were assigned into two groups: together with butorphanol [0.2 mg kg^?1 intramuscularly (IM)], group AA (n = 14) received acepromazine (0.1 mg kg^?1 IM) and group MA (n = 14) medetomidine (20 μg kg^?1 IM). Anaesthesia was induced with alfaxalone to effect [0.2 mg kg^?1 intravenously (IV) every 20 seconds], initially maintained with 8 mg kg^?1 hour^?1 alfaxalone IV and infusion adjusted (±0.5 mg kg^?1 hour^?1) every five minutes according to alterations in heart rate (HR), respiratory rate (f_R), Doppler blood pressure (DBP) and presence of palpebral reflex. Additional alfaxalone boli were administered IV if cats moved/swallowed (0.5 mg kg^?1) or if f_R >40 breaths minute^?1 (0.25 mg kg^?1). Venous blood samples were obtained to determine plasma alfaxalone concentrations. Meloxicam (0.2 mg kg^?1 IV) was administered postoperatively. Data were analysed using linear mixed models, Chi-squared, Fishers exact and t-tests.ResultsAlfaxalone anaesthesia induction dose (mean ± SD), was lower in group MA (1.87 ± 0.5; group AA: 2.57 ± 0.41 mg kg^?1). No cats became apnoeic. Intraoperative bolus requirements and TIVA rates (group AA: 11.62 ± 1.37, group MA: 10.76 ± 0.96 mg kg^?1 hour^?1) did not differ significantly between groups. Plasma concentrations ranged between 0.69 and 10.76 μg mL^?1. In group MA, f_R, end-tidal carbon dioxide, temperature and DBP were significantly higher and HR lower.Conclusion and clinical relevanceAlfaxalone TIVA in cats after medetomidine or acepromazine sedation provided suitable anaesthesia with no need for ventilatory support. After these premedications, the authors recommend initial alfaxalone TIVA rates of 10 mg kg^?1 hour^?1.     

Specific GABAA circuits for visual cortical plasticity

Weak inhibition within visual cortex early in life prevents experience-dependent plasticity. Loss of responsiveness to an eye deprived of vision can be initiated prematurely by enhancing gamma-aminobutyric acid (GABA)-mediated transmission with benzodiazepines. Here, we use a mouse "knockin" mutation to alpha subunits that renders individual GABA type A (GABA(A)) receptors insensitive to diazepam to show that a particular inhibitory network controls expression of the critical period. Only alpha1-containing circuits were found to drive cortical plasticity, whereas alpha2-enriched connections separately regulated neuronal firing. This dissociation carries implications for models of brain development and the safe design of benzodiazepines for use in infants.     

Gender disparity in liver cancer due to sex differences in MyD88-dependent IL-6 production

Hepatocellular carcinoma (HCC), the most common liver cancer, occurs mainly in men. Similar gender disparity is seen in mice given a chemical carcinogen, diethylnitrosamine (DEN). DEN administration caused greater increases in serum interleukin-6 (IL-6) concentration in males than it did in females. Furthermore, ablation of IL-6 abolished the gender differences in hepatocarcinogenesis in mice. DEN exposure promoted production of IL-6 in Kupffer cells (KCs) in a manner dependent on the Toll-like receptor adaptor protein MyD88, ablation of which also protected male mice from DEN-induced hepatocarcinogenesis. Estrogen inhibited secretion of IL-6 from KCs exposed to necrotic hepatocytes and reduced circulating concentrations of IL-6 in DEN-treated male mice. We propose that estrogen-mediated inhibition of IL-6 production by KCs reduces liver cancer risk in females, and these findings may be used to prevent HCC in males.