Interdisciplinary analysis of homegardens in Nicaragua: micro- zonation, plant use and socioeconomic importance

The choice of plant species, their arrangement and management varies between and within tropical homegardens in the same community. Relationships between agroecological and socioeconomic characteristics of 20 homegardens were examined at Masaya, Nicaragua. Variables analyzed were micro-zonation (area allocation to specific uses and management), plant use and diversity, occupation, labor investment, and product, benefit and income generation. Data was collected through surveys, participatory mapping, plant inventories, direct observation and interviews. Ten different micro-zones and nine plant uses were identified. Fruit trees, shaded coffee and ornamentals were the most important zones. Plant diversity was high, with a sample total of 324 species. Homegardens were an important occupation, with average labor investments of 32.6 h family^–1 week^–1. Families obtained at least 40 different plant products from homegardens, as well as the benefit of space for working and socializing. Six homegarden types were identified using a cluster analysis based on biophysical variables. Types reflected the relationship between income generation and the number and types of zones and plant species present. Labor inputs were high considering the small size of the homegardens (average size 3,240 m²), although no clear relationships between labor investment and plant and zone type or number were observed. Homegarden management strategies of plant selection and zonation were affected both by family choices and external forces. Although dependence on homegardens may vary according to specific conditions at a given time, they seem to be a consistent, flexible resource used to meet a diversity of needs. The methodological approach used in this paper may be appropriate for the study of other traditional agroecosystems since it includes both biophysical and socioeconomic variables, essential for understanding these complex systems.     

Tobacco necrosis virus A overcomes local cell death response in Nicotiana tabacum

Tobacco necrosis virus A (TNVA) belongs to the genus Alphanecrovirus in the Tombusviridae family. Symptoms induced by TNVA include necrotic lesions on inoculated leaves in a wide host range. The necrotic cell death response to certain viruses is poorly understood. This study characterizes the mechanisms underlying the local cell death triggered by TNVA in Nicotiana tabacum, showing that it shares several components with the hypersensitive response (HR) mediated by resistance proteins. TNVA perception triggers the accumulation of local viral-derived small interference RNA and the regulation of biological processes related to pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI), including hydrogen peroxide accumulation, cell wall reinforcement, the activation of unfolded protein response and the induction of salicylic acid (SA) and SA-dependent pathways. However, these antiviral defences do not prevent either local virus multiplication or systemic movement, leading to disease development. Nevertheless, SA-deficient NahG tobacco plants challenged with TNVA showed an increase in virus accumulation on noninoculated leaves, which was correlated with the development of systemic necrosis, highlighting the role of SA signalling in TNVA-induced defence. In addition, SA treatment enhanced the local defence response to TNVA infection and suppressed systemic necrosis in N. benthamiana. Taken together, our data suggest that TNVA induces an impaired plant defence response by modulating host factors to persist at low levels in distal tissues.     

Safety and accuracy of blind vs. ultrasound-guided dorsal retrobulbar nerve blocks in horses—A cadaveric study

Objective

There is limited knowledge regarding the safety and accuracy of ultrasound-guided retrobulbar nerve blocks in horses. The aim of this study was to compare these parameters between blind and ultrasound-guided injection techniques for the dorsal retrobulbar nerve block in horses.

Methods

Equine cadaver heads were used to inject the retrobulbar space with contrast medium (CM). Injections were performed either blindly based on anatomic landmarks (blind group, n = 44) or under ultrasonographic guidance (US-group, n = 44), equally divided between an experienced and unexperienced operator. Needle position and distribution of CM were assessed with computed tomography imaging and evaluated by a board-certified veterinary diagnostic imager blinded to the technique. Safety and accuracy of both techniques were compared.

Results

Ocular penetration was observed in two cases (n = 2/44) in the blind group but not in the US group (n = 0/44). No intrathecal, intraneural, or intravascular injections were seen in either group. Safety was significantly improved in the US group (p = .026). There was no statistically significant difference between the groups regarding the accuracy of the injection. Excellent accuracy was achieved more often with the ultrasound-guided technique (n = 11/22) than with the blind technique (n = 7/22) when performed by the unexperienced operator, but this difference was not statistically significant.

Conclusion

To prevent globe-threatening complications and improve the safety of the injection, we recommend using the ultrasound-guided injection technique for the dorsal retrobulbar nerve block.     

Effects of two continuous infusion doses of lidocaine on isoflurane minimum anesthetic concentration in chickens

ObjectiveTo assess the effect of two intravenous (IV) doses of lidocaine on the minimum anesthetic concentration (MAC) of isoflurane in chickens.Study designBlinded, prospective, randomized, experimental crossover study.AnimalsA total of six adult female chickens weighing 1.90 ± 0.15 kg.MethodsChickens were anesthetized with isoflurane and mechanically ventilated. Isoflurane MAC values were determined (T0) in duplicate using an electrical noxious stimulus and the bracketing method. After MAC determination, a low dose (LD; 3 mg kg^–1 followed by 3 mg kg^–1 hour^–1) or high dose (HD; 6 mg kg^?1 followed by 6 mg kg^?1 hour^–1) of lidocaine was administered IV. MAC determination was repeated at 1.5 (T1.5) and 3 (T3) hours of lidocaine administration and blood was collected for analysis of plasma lidocaine and monoethylglycinexylidide (MEGX) concentrations. Pulse rate, peripheral hemoglobin oxygen saturation, noninvasive systolic arterial pressure and cloacal temperature were recorded at T0, T1.5 and T3. Treatments were separated by 1 week. Data were analyzed using mixed-effects model for repeated measures.ResultsMAC of isoflurane (mean ± standard deviation) at T0 was 1.47 ± 0.18%. MAC at T1.5 and T3 was 1.32 ± 0.27% and 1.26 ± 0.09% (treatment LD); and 1.28 ± 0.06% and 1.30 ± 0.06% (treatment HD). There were no significant differences between treatments or times. Maximum plasma lidocaine concentrations at T3 were 496 ± 98 and 1200 ± 286 ng mL^–1 for treatments LD and HD, respectively, and were not significantly different from T1.5. With treatment HD, plasma concentration of MEGX was significantly higher at T3 than at T1.5. Physiological variables were not significantly different among times with either treatment.Conclusions and clinical relevanceAdministration of lidocaine did not significantly change isoflurane MAC in chickens. Within treatments, plasma lidocaine concentrations were not significantly different at 1.5 and 3 hours.     

Evaluation of histological grade and histologically tumour‐free margins as predictors of local recurrence in completely excised canine mast cell tumours

Completeness of mast cell tumour (MCT) excision is determined by assessment of histologically tumour‐free margins (HTFM). The HTFM width necessary to prevent local recurrence (LR), recognized as histologic safety margin (HSM) in human oncology, has not been defined. We hypothesized that HTFM width would correlate with risk for LR and high‐grade tumours would require wider HTFM than low‐grade tumours. Records of dogs with completely excised MCTs were included. Signalment, two‐tier tumour grade, tumour size, HTFM width, recurrence and therapy data was collected. High‐grade (n = 39) tumours were more likely to recur than low‐grade (n = 51) tumours (35.9% versus 3.9%), P < 0.0001, with no association between HTFM width and LR. Twenty‐nine percent of low‐grade tumours had HTFM less than 3 mm; none recurred. Narrow (≤3 mm) histologic margins are likely adequate to prevent LR of low‐grade tumours. High‐grade tumours have significant risk of LR regardless of HTFM width.     

11个阔叶树种在粤西地区的早期生长表现

2003年在信宜进行了53个阔叶树种生长比较试验,选择其中11个树种进行调查分析,结果表明:11个阔叶树种在粤西地区具有极强的适应性;多个阔叶树种在粤西地区的早期表现良好,生长表现最好的树种是藜蒴和红椎。     

Effects of Energy and Protein Supplementation on the Production and Economic Efficiency of Scavenging Improved (Tamhoang) and Local (Ri) Breed Hens under Smallholder Conditions in North Vietnam

The objectives of this study were to evaluate the effects of supplementing maize meal and soybean meal, separately or mixed, on egg production performance of two breeds of scavenging hens under on-farm conditions. Treatments were: (1) confined, with a mixed feed (75% maize meal and 25% soybean meal) ad libitum (CMF); (2) scavenging, with a supplement of 60 g/bird per day of maize meal (ScM); (3) scavenging, with a supplement of 25 g/bird per day of soybean meal (ScS); (4) scavenging, with 54 g/ bird per day of the mixed feed (ScMF). Mean hen-day production was 21.8%, 19.8%, 17.7% and 22.8% for the CMF, ScM, ScS and ScMF treatments, respectively (p <0.05), and was significantly (p <0.001) higher for the improved Tamhoang breed (24.4%) than for the local Ri hens (16.7%). Mean egg weight was significantly higher for the Tamhoang (53.2 g) compared to the Ri hens (45.0 g) (p<0.01). Feed consumption per kilogram of eggs was significantly higher for the CMF treatment compared to the other treatments and was lower for the ScS compared to the other scavenging treatments (p <0.05). Feed cost per kilogram of eggs was lowest for the ScM treatment and was 30 to 40% higher for the confined treatment compared to the scavenging treatments. Feed consumption and cost of feed per kilogram of eggs were significantly lower for the Tamhoang than for the Ri hens.     

信阳民歌的发展过程及新民歌创作

"民歌"是民族地域文化的重要组成部分,具有地方色彩。社会经济的发展影响着民歌的创作与发展,民歌的发展影响着民族音乐的发展。本文从分析信阳民歌的发展过程入手,探索信阳新民歌的创作。     

Distribution of a lidocaine-methylene blue solution staining in brachial plexus, lumbar plexus and sciatic nerve blocks in the dog

ObjectiveTo determine the influence on the distribution of the volume of a local anaesthetic-methylene blue solution at three different nerve block sites in the dog.Study designRandomized, controlled, blinded experimental trial.Animals23 hound-cross dogs weighing 16–40 kg and aged 2 ± 0 years (mean ± SD).MethodsDogs were anaesthetized and randomly assigned to three groups of seven or eight dogs each, based on volume administered: low, medium and high volume (L, M and H). Using electrolocation, the injection was performed after a positive response was elicited (flexion of the elbow for the brachial plexus block, quadriceps contractions for the lumbar plexus and dorsiflexion/plantar extension of the foot for the sciatic nerve block). At the brachial plexus site, groups L, M and H received 0.075, 0.15 and 0.3 mL kg⁻¹, respectively. At the lumbar plexus site, groups L, M and H received 0.1, 0.2 and 0.4 mL kg⁻¹, respectively. At the proximal sciatic nerve site, groups L, M and H received 0.05, 0.1 and 0.25 mL kg⁻¹, respectively. Necropsies were performed immediately following euthanasia. Staining of ≥2 cm along the nerve was considered sufficient; the proportions sufficient were compared with Fisher's exact test. The volume was recommended when all the relevant nerves were stained sufficiently in all or all but one of the dogs within the group.ResultsIn the brachial plexus, only in group H were all the nerves stained sufficiently. In the lumbar plexus site, no statistical difference was found, but we suggest the H group volume to balance sufficient and excessive staining. At the sciatic nerve site, all volumes tested produced sufficient staining in all (or all but one) dogs.Conclusions and clinical relevanceVolumes of 0.3 and 0.05 mL kg⁻¹ produced sufficient distribution for performing brachial plexus, and sciatic nerve blocks, respectively. Additionally, a volume of 0.4 mL kg⁻¹ might also be adequate for a lumbar plexus block (no statistical significance was reached).     

Comparison of intraperitoneal ropivacaine and bupivacaine for postoperative analgesia in dogs undergoing ovariohysterectomy

Objective

To compare postoperative analgesia following either intraperitoneal (IP) ropivacaine or bupivacaine in dogs undergoing ovariohysterectomy (OVH) in the scope of multimodal analgesia.