Calcite Dissolution: An in situ Study in the Panama Basin

The results of an in situ study of calcite dissolution in the Panama Basin indicate that the rate of dissolution in the water column increases suddenly below a water depth of about 2800 meters. This coincides with the depth at which the calcium carbonate content of surface sediments begins to decrease rapidly or the sedimentary lysocline. Since this level of increased dissolution both in the water column and on the sea floor does not appear to be related to the transition from supersaturation to undersaturation with respect to carbonate, there may be a kinetic origin for the lysocline in this region.     

N-acetylhistidine isolated from frog heart

A diazo-positive comitpound was found in an extract of frog heart. This substance showed a negative ninhydrin reaction and had on a paper chromatogram developed with a phenol-hydrochloric acid solvent system a higher R(F) than carnosine. The substance, isolated by chrolnatography, was identified as N-acetyl-L-histidine.     

Elementary-body virus isolated from clinical trachoma in California

From an adult white resident of California with clinically typical early trachoma a virus was isolated by growth in embryonated eggs. Morphologically and serologically the virus belongs in the psittacosis-lymphogranuloma group. When it is instilled into monkey eyes it produces acute follicular conjunctivitis with typical inclusion bodies.     

Salivary gland lysates from the sand fly Lutzomyia longipalpis enhance Leishmania infectivity

Leishmaniasis is a parasitic disease transmitted by phlebotomine sand flies. The role of sand fly saliva in transmission of the disease was investigated by injecting mice with Leishmania major parasites in the presence of homogenized salivary glands from Lutzomyia longipalpis. This procedure resulted in cutaneous lesions of Leishmania major that were routinely five to ten times as large and contained as much as 5000 times as many parasites as controls. With inocula consisting of low numbers of Leishmania major, parasites were detected at the site of injection only when the inoculum also contained salivary gland material. This enhancing effect of sand fly salivary glands on cutaneous leishmaniasis occurred with as little as 10 percent of the contents of one salivary gland of one fly. Material obtained from other bloodsucking arthropods could not mediate the phenomenon.     

Actomyosin-like protein isolated from mammalian brain

A protein with characteristics similar to actomyosin has been isolated from whole brain of rat and cat. It is soluble in 0.6 molar potassium chloride and insoluble in 0.1 molar potassium chloride. It superprecipitates with magnesium ions and adenosine triphosphate. It has adenosine triphosphatase activity stimulated by either magnesium or calcium ions. Both superprecipitation and adenosine triphosphatase activity are inhibited by p-chloromercuribenzoate and Mersalyl but not by ouabain.     

羊源链球菌的分离鉴定

为了确定重庆市山羊败血性链球菌病的病原，并研究其生物学特性，为有效防治该病提供科学依据和指导，作者从具有典型败血症和纤维素性胸膜肺炎病变的南江黄羊中分离到5株羊源链球菌，经血清学、生物学等试验证明为该病的病原。该菌革兰氏染色阳性、β溶血，瑞氏染色可见英膜，大多呈短链状。能发酵葡萄糖、乳糖、蔗糖、山梨醇、杨苷；能水解淀粉和精氨酸；马尿酸钠水解、胆汁溶菌和美蓝还原试验阴性。以1号菌株制备的抗原能与病羊及康复羊血清产生凝集反应，而所有血清不能与羊肺炎支原体和丝状支原体山羊亚种间接血凝抗原发生反应。分离菌腹腔接种小鼠全部致死。分离菌株对青霉素、磺胺甲基异恶唑具抗药性，对氨苄青霉素、环丙沙星、头孢曲松钠高敏。根据形态学、培养特性、生化特性及动物试验结果，初步认为属于马腺疫链球菌兽疫亚种。     

Persistence without pathology in phosphoglycan-deficient Leishmania major

Leishmania infections involve an acute phase of replication within macrophages, typically associated with pathology. After recovery parasites persist for long periods, which can lead to severe disease upon reactivation. Unlike the role of host factors, parasite factors affecting persistence are poorly understood. Leishmania major lacking phosphoglycans (lpg2-) were unable to survive in sand flies and macrophages, but retained the ability to persist indefinitely in the mammalian host without inducing disease. The L. major lpg2- thus provides a platform for probing parasite factors implicated in persistence and its role in disease and immunity.     

蜜蜂螺原体南京分离株M10形态的多样性

为进一步了解蜜蜂螺原体的生长、生殖及致病特点,以分离自患"爬蜂病"蜜蜂体内的螺原体菌株M10为研究对象,测定了其生长曲线,利用透射电镜观察其不同生长期的形态.结果表明:在R-2培养基中,不同生长期的蜜蜂螺原体M10形态差异很大,但其形态变化又具有一定的规律性.延滞期的M10以粗短的形态为主;在对数期和稳定期,M10具有丰富的形态多样性,如芽状、分支状、串珠状等;到达衰亡期,M10则变得细长,菌体自身及菌体之间极易缠绕并聚集成团.此外,观察到M10具有尖端结构和纤毛状结构,大多数菌体具有"一尖一圆"结构,纤毛状结构长度差异显著.本研究首次描述了不同生长期蜜蜂螺原体的形态变化,发现螺原体纤毛状结构最长可达1 860.5 nm,并首次在人工培养基中发现螺原体具有类似纤毛接合现象.     

Political economic history,culture, and Wounaan livelihood diversity in eastern Panama

A growing literature on scholarly and practical approaches to conservation and development uses a livelihood approach to understand rural peoples’ diverse assets and activities, especially as they serve to minimize vulnerability to economic and ecological shocks. In recent years, the suite of potential assets available to rural households has been theorized as human, natural, physical, social, and cultural capitals and includes the context in which they are used. Here we explore Wounaan livelihood strategies and how they articulate with the dynamic political economic history of eastern Panama. Known in Panama as forest dependent swiddeners, semi-structured interviews and participant observation revealed Wounaan’s increasing reliance on fishing, artisanship, and ecotourism in their income profiles. While these income sources are linked to decreasing land availability and increasing market opportunities, we address the role of cultural beliefs and values in Wounaan negotiation of their income strategies. J. Vela′squez Runk has studied ecology and anthropology in eastern Panama for ten years. Presently she is a Resident Scholar at the School of American Research in Santa Fe, New Mexico. Gervacio Ortíz is a business student at the University of Panama and a resident of Majé, Panama. Wilio Quintero is a resident of Boca Lara, Panama. Cristobalino Quiróz is a resident of Boca Lara, Panama.     

福建省豆科树木的丛枝菌根真菌

从福建省9地市的栽培及野生豆科树木根际分离出丛枝菌根真菌2属8种。其中，球囊霉属有缩球囊霉(Glomus constrictum)、苏格兰球囊霉(G．caledonium)、摩西球囊霉(G．mosseae)、隐球囊霉(G．occultum)、幼套球囊霉(G．etunicatum)、地球囊霉(G．geosporum)、何氏球囊霉(G．hoi)等7种，无梗内囊属有细凹无梗囊霉(Acaulospora scrobiculata)1种;幼套球囊霉较其他种类出现频率高，孢子数量多，初步认为是福建省豆科树木丛枝菌根真菌的优势种。     

Culex (Melanoconion) aikenii: natural vector in Panama of endemic Venezuelan encephalitis

Experiments performed in an endemic area of Venezuelan equine encephalitis in the Panama Canal Zone demonstrated transmission of Venezuelan equine encephalitis virus from naturally infected Culex aikenii mosquitoes to laboratory hamsters. Results of experiments indicate that Culex aikenii is an efficient natural vector and the principal species of mosquito transmitting Venezuelan equine encephalitis in this endemic zone.     

鸡源金黄色葡萄球菌耐药性分析

采用药敏纸片扩散法,测定48株鸡源金黄色葡萄球菌对常用的19种抗菌药物的耐药性,检测耐甲氧西林金黄色葡萄球菌(MRSA).结果表明:所有菌株除对万古霉素、头孢西丁和头孢唑啉100%敏感以外,对其他16种药物均产生不同程度的耐药性,其中耐药率较高的有四环素、强力霉素、环丙沙星、氧氟沙星、诺氟沙星及克林霉素,耐药率最低的为头孢噻肟、阿米卡星、复方新诺明及利福平.100%的菌株呈多重耐药,分离菌株最少耐受4种药物,最多耐受12种药物,未检测出耐甲氧西林的金黄色葡萄球菌.     

分离自扎龙湿地的一株降解纤维素细菌的鉴定

从扎龙湿地底泥中分离到一株能够降解纤维素的细菌。该菌株光学显微镜下呈短杆菌,大小约(0.3~1.0)μm×(1.0~3.5)μm,无芽孢,革兰氏染色反应为阴性,无运动性。最适生长温度为30℃,最适生长pH为7.0。对该菌株进行形态特征观察、生理生化反应与16S rDNA序列分析鉴定,菌株ZL-5为Aeromonassalmonicida sp.Salmonicida。     

单叶蔓荆内生真菌多样性研究

对鄱阳湖区道地药材单叶蔓荆(Vitex trifolia)的内生真菌种类组成和多样性进行分析.结果表明,从单叶蔓荆中共分离获得226株内生真菌,鉴定出214株菌株,属4纲5目6科27属;其中,青霉属(Penicillium)为优势属、占总株数的12.39％,其次为单端孢属(Trichothecium)、丛梗孢属(Monilia)、链格孢属(Alternaria),分别占总株数的8.41％、7.96％、7.52％,另有12株因不产孢而未被鉴定.研究发现单叶蔓荆内生真菌在植株内的分布随部位和季节的不同存在差异.     

三七病原根结线虫的分子鉴定

利用设计合成的1对北方根结线虫（Meloidogyne hapla）特异性寡聚核苷酸引物Mh-F／Mh-R,以北方根结线虫、南方根结线虫、花生根结线虫和爪哇根结线虫全基因组DNA为对照,对采自云南文山、砚山、马关、蒙自等地区的三七根结线虫全基因组DNA进行PCR特异性扩增。结果表明,设计合成的引物能从北方根结线虫和供试的4个三七病原根结线虫全基因组DNA中扩增到462bp长度的分子片段,而南方根结线虫、花生根结线虫和爪哇根结线虫的全基因组DNA无扩增产物。表明4个地区的三七病原根结线虫种群均为北方根结线虫,该对引物可用于三七根结线虫的分子鉴定。     

Fast-growing rhizobia isolated from root nodules of soybean

Fast-growing rhizobia have been isolated from soybean root nodules collected in China. These new isolates are physiologically distinct from slow-growing soybean rhizobia. They formed effective nitrogen-fixing associations with wild soybean and an unbred soybean cultivar from China, but were largely ineffective as nitrogen-fixing symbionts with common commercial cultivars of soybeans.