Lessons from Unsuccessful Attempts to Establish Spodoptera pectinicornis (Lepidoptera: Noctuidae), a Biological Control Agent of Waterlettuce

We released nearly 332 000 Spodoptera pectinicornis individuals for biological control of the floating aquatic weed Pistia stratiotes (waterlettuce) at 22 sites in Florida during December 1990-December 1997. Predation (by boat-tailed grackles, fire ants, and spiders) and Allee effects (resulting from rapid dispersal of adults) prevented populations from persisting during early attempts. These efforts consisted of small releases at multiple sites, with no nurturing of the introduced populations. Modification of our initial approach resulted in a series of release strategies that consisted of multiple releases at fewer sites and employed progressively more intensive nurturing of the introduced populations. The most successful strategy incorporated: (i) cages to restrict adult dispersal and exclude flying predators; (ii) plant-free zones around the cages to exclude crawling predators; (iii) enhancement of the nutritional quality of waterlettuce in the cages; and (iv) frequent inoculation of the cages with laboratory-reared insects. Use of this strategy resulted in several provisionally-established S. pectinicornis populations, numbering as much as 23.5 S. pectinicornis individuals m -2 , and produced up to seven post-release generations. Unfortunately, all of these incipient populations declined until S. pectinicornis was undetectable. We conclude that field populations of this moth no longer persist in Florida, and offer an introspective assessment of how this project might have been improved.     

氨氮对鱼类毒性的影响因子及气呼吸型鱼类耐氨策略

氨氮广泛存在于养殖水体中,在氨氮过高的养殖环境下可能会导致鱼类的大量死亡。从生态、环境及养殖效益角度来看,研究氨氮对鱼类的毒性以及鱼类应对环境或体内高氨浓度的策略均具有重要意义。某些鱼类具有其特殊的策略来降低氨毒性,使得这些种类能适应极高的环境或体内氨浓度。这些耐氨策略主要为(1)合成谷氨酰胺、(2)合成尿素排出、(3)增强机体排泄、(4)Rh蛋白促进氨解毒、(5)降低周围环境pH、(6)NH_3挥发和体表碱化、(7)降低体内氨生成、(8)特定氨基酸代谢生成丙氨酸、(9)组织高氨耐受性。鱼类的氨耐受策略较多而且是可变的,主要受特定种类的生活习性和栖息环境影响。文章综述了氨氮对鱼类的毒性机理以及鱼类的应对策略,为相关的研究提供基础资料。     

An attempted within-group infanticide in wild chimpanzees

Two high-ranking adult male chimpanzees (Pan troglodytes) of M group in the Mahale Mountains National Park, Tanzania, tried to get a newborn female infant of an adult female who was born in M group. The mother was not seen to mate with these adult males during the probable conception cycle of the infant, but she disappeared from the group during the later cycle, when she may have been inseminated by a male of one of the neighboring unit groups. The adult males failed to get the infant because the grandmother of the newborn and her female friend cooperated to protect the mother and infant from attacks by the males. The sexual selection hypothesis for infanticide by adult male chimpanzees holds for this observed case. The sudden disappearance of another infant, a healthy female, strongly suggests the killing of female infants too. Therefore, the asserted male-biased infanticide in chimpanzees appears to be less tenable.     

A machine-learning method for classifying and analyzing foot placement: Application to manual material handling

Foot placement strategy is an essential aspect in the study of movement involving full body displacement. To get beyond a qualitative analysis, this paper provides a foot placement classification and analysis method that can be used in sports, rehabilitation or ergonomics. The method is based on machine learning using a weighted k-nearest neighbors algorithm. The learning phase is performed by an observer who classifies a set of trials. The algorithm then automatically reproduces this classification on subsequent sets. The method also provides detailed analysis of foot placement strategy, such as estimating the average foot placements for each class or visualizing the variability of strategies. An example of applying the method to a manual material handling task demonstrates its usefulness. During the lifting phase, the foot placements were classified into four groups: front, contralateral foot behind, ipsilateral foot behind, and parallel. The accuracy of the classification, assessed with a holdout method, is about 97%. In this example, the classification method makes it possible to observe and analyze the handler’s foot placement strategies with regards to the performed task.     

Reduced intensity in gait-slip training can still improve stability

Perturbation training with “free” slips (i.e., with long slip distance) has been able to successfully improve stability and to reduce the incidence of falls among older adults. Yet, it is unclear whether a highly constrained training with reduced slip distance (and hence training intensity) can achieve similar effects. The purpose of this study was to investigate whether short-distance slips could also improve the control of stability, and whether such improvements could be generalized to a novel, “free” slip. Thirty-six young subjects were randomly assigned to either one of the two training groups, which underwent seven training trials with constrained slips of either 12-cm or 18-cm in distance before encountering a novel, “free” slip (up to 150 cm) in the test trial; or the control group, which only experienced the same test trial of a novel, “free” slip. The results showed that while both training groups were able to significantly improve their control of stability in training; the 18-cm group had significantly better reactive control of stability than the 12-cm group. During the “free” slip, such advantage enabled the 18-cm group to exhibit significantly less balance loss incidence than 12-cm group (58.3 vs. 83.3%) and the controls (100%). These differences could be fully accounted for when we assume that the central nervous system directly controls slip velocity or slip distance during adaptation, whereby the level of similarity between training trials and the test trial governs the degree of generalization. The findings that low intensity training may still improve stability warrant further investigations among older adults.     

Plant Conservation in the Future: New Challenges, New Opportunities

Throughout the world, plant diversity is being reduced rapidly by the extinction of species and of local differentiated populations. In presenting possible solutions to this very serious problem Ⅰ will first briefly describe the factors that have led to the development of China's wealth of biodivenity; then examine the causes of extinction,with an emphasis on the situation in China; and conclude with recommendations on how to most effectively conserve plants in this huge and botanically diverse country.     

喉癌患者术后感染的危险因素分析及干预对策探讨

目的:探讨喉癌患者手术部位发生感染(Surgical site infection,SSI)的相关危险因素及干预对策,为临床预防提供参考。方法:回顾性分析2012年7月-2013年11月因喉癌而在我院行喉切除术的83例患者的临床资料,根据术后是否发生SSI将患者分为感染组(n=12例)和非感染组(n=71例)。分析两组患者术后SSI的危险因素,并提出相应护理对策。结果:83例患者中,12例术后发生SSI,发生率为14.46%;单因素分析显示,感染组和非感染组在临床III期以上、术前气管切开、手术时间4 h、全喉切除等方面存在显著差异性(P0.05);多因素回归分析显示:患者的临床分期、术前气管是否切开、手术时间及手术切除方式是术后发生SSI的独立危险因素(P0.05)。结论:喉癌术后感染与临床分期、手术时间及切除方式等因素有关,采取有效的干预对策可减少术后SSI的发生率。     

脊柱外科术后病原菌感染分析

目的研究并分析脊柱外科术后病原感染情况以及干预措施。方法选取我院2015-2020年接受脊柱外科手术治疗并发生术后感染的患者183例为研究对象,使用生理盐水对患者手术切口进行擦拭,收集患者血液、分泌物、穿刺液并送检,并对病原菌进行培养与鉴别并进行药敏试验。根据试验结果选择合适的药物进行干预。结果183例患者发生感染的主要类型是切口感染(105例,57.4%),共分离出143株病原菌。其中:75株革兰阳性菌,占52.4%;60株革兰阴性菌,占42.0%;8株真菌,占5.6%。革兰阳性菌对万古霉素(VA)无耐药性,肺炎克雷伯菌对环丙沙星(CIP)、亚胺培南(IPM)和头孢哌酮/舒巴坦(SCF)无耐药性,大肠埃希菌对亚胺培南(IPM)无耐药性。结论脊柱外科术后感染中切口是感染主要部位,金黄色葡萄球菌和肺炎克雷伯菌是主要病原菌,可以使用VA治疗金黄色葡萄球菌感染,使用CIP、IPM、SCF治疗肺炎克雷伯菌感染。     

健康教育干预应用于喉切除术后患者的效果观察

目的：探讨健康教育干预应用于喉切除术后患者的临床效果。方法：将符合诊断标准的86例患者随机分为观察组、治疗组,对照组给予常规护理,观察组给予鼻饲营养健康教育、咳嗽方法健康教育、吞咽功能健康教育、语言训练健康教育等健康教育措施。结果：两组平均住院时间比较,观察组平均住院时间（18．8±5.3）d,明显少于对照组的（21．5±5．2）d,差异有统计学意义（t=2．3845,P〈0．05）。两组并发症发生率比较,观察组并发症发生率2.32％明显少于对照组的18．60％,差异有统计学意义（χ^2=4．47,P〈0．05）。结论：健康教育干预可增强护理人员与患者之间的互动、促进护患关系融洽,增进患者对护理人员的尊重、信任,增加了患者对自身疾病的了解,及自我护理能力的提高,增加了战胜疾病的信心,提高了生活质量。值得临床进一步推广应用。     

B群脑膜炎球菌疫苗的研制策略

脑膜炎奈瑟菌主要引起儿童细菌性脑脊髓膜炎和败血症,有较高的发病率和病死率。现用疫苗能够控制A、C、W135和Y群脑膜炎球菌引起的感染,而由于B群荚膜多糖免疫原性弱,外膜蛋白变异性高等原因,仍无安全和具有广泛保护性的疫苗用于控制B群脑膜炎球菌的感染。目前,B群脑膜炎球菌大多已成为引起发达国家侵袭性脑膜炎疾病的主要病原体。随着研究的不断深入,B群脑膜炎球菌疫苗的研究已经取得了很大的进展,外膜囊(Out membrane vesicles,OMV)疫苗已经在控制特异性菌株爆发流行中取得了成功。然而,人们对具有广泛保护性的B群脑膜炎球菌疫苗的探索仍在继续。本文对近年来B群脑膜炎球菌基于不同型抗原疫苗的各种研制策略及其存在的问题进行了综述。