Effects of soil fumigation on soil nitrogen and on disease incidence in winter wheat

Winter wheat was grown in soil fumigated with D-D, 85% dazomet dust or formalin, and top-dressed with o or 125 kg nitrogen/ha. Six weeks after fumigation, there was much more ammonium nitrogen in fumigated than in unfumigated soil. Nitrate was also more after fumigation with dazomet, but less after D-D and formalin. After 5 months, only D-D plots had less nitrate and more total mineral nitrogen than unfumigated plots. Take-all (Ophiobolus graminis) was less prevalent in the first crop after dazomet or formalin, but was more prevalent in the second crop than after other treatments. Eyespot (Cercosporella herpotrichoides) was decreased only by formalin and only in the first crop after applying it. Fumigation had little effect on the incidence of other diseases recorded or on grain yield, except that yields were light on D-D plots in the first crop after fumigation, when ears were severely deformed.     

The social grooming of captive female rhesus monkeys: Effects of the births of their infants

We observed the grooming interactions of 13 female rhesus monkeys (Macaca mulatta)before and for 12 weeks after the births of their infants. Mothers groomed for similar amounts of time before and after the birth of their infants, but after the birth, the grooming they directed to their infants may have been at the expense of that directed to other partners. Lactating females did not receive more grooming from other females but were approached more often, suggesting that they were more attractive. Mothers that groomed their infants most groomed others least, as if grooming time was limited for each mother or as if she was trying to compensate for avoiding interactions with other partners. Mothers of male infants groomed others more than mothers with female infants did, which might be due to mothers with daughters receiving more aggression and therefore avoiding interaction. Experienced and high-ranking mothers groomed their newborn infants considerably more than primiparous mothers did in the 24 hr following birth. Grooming was preferentially directed at close kin before the births of the infants. Mothers tended to groom higher-ranked partners more than they were groomed by them, and they tended to receive more grooming from lower-ranked partners than they gave, as suggested in models of rank attractiveness.     

Prospectively randomised trial of proximal gastric vagotomy either with or without pyloroplasty in treatment of uncomplicated duodenal ulcer.

A consecutive series of 100 men with uncomplicated duodenal ulcer was randomly divided into two groups: one group of 52 underwent proximal gastric vagotomy (PGV), the other group (48) underwent PGV with pyloroplasty (PGVP). Preoperative peak acid output (PAOP) was measured in all patients. Those with a higher preoperative PAOP were significantly more likely to develop recurrent ulceration. Three patients developed recurrent ulceration after PGV and seven after PGVP. Dumping was both more common and more severe after PGVP than PGV. An overall satisfactory result was achieved in 92% after PGV and 81% after PGVP. We conclude that combining pyloroplasty with PGV has no appreciable advantages.     

Enhanced transport of natural amino acids after activation of pig lymphocytes.

Na+-dependent uptake of the amino acids L-proline and L-methionine was greatly accelerated when pig lymphocytes were activated with phytohaemagglutinin or other mitogens. The increased influx was apparent after incubation with phytohaemagglutinin for 1 h, and reached a maximum after 24 h. The lymphocytes appear to possess at least three different transport systems for neutral amino acids with properties similar to, but not identical with, those described for other cells. The activity of a system resembling the A system of other cells was increased most dramatically after activation, its activity in unstimulated lymphocytes being extremely low or absent. A second Na+-dependent system, which has properties similar to those of the ASC system in other cells, but with a broader specificity for amino acids, was more active in unstimulated lymphocytes, and uptake by this system was also accelerated after incubation with phytohaemagglutinin. The activity of a third system, very similar to the L system in other cells, was increased to a much smaller extent after lymphocyte activation.     

Aggression in the early phases of the reproductive cycle of the male three-spined stickleback (Gasterosteus aculeatus)

Male sticklebacks with nests were more aggressive towards other males than were males which had yet to build nests.Males with nests were more aggressive towards other males than towards non-gravid females. This was not true of fish that had yet to build nests.The increased aggression shown to other males by males with nests was reduced after gonadectomy to the level characteristic of fish that had yet to build nests. This reduction occurred in the first week after the operation. Gonadectomy had no immediate effect on the aggression shown to non-gravid females.The aggression of males that had still to build nests was not reduced by gonadectomy.Gonadectomy resulted in a complete absence of nest building and nest-directed behaviour.     

Cleanability in relation to bacterial retention on unused and abraded domestic sink materials

The relative cleanability of stainless steel, enamelled steel, mineral resin and polycarbonate domestic sink materials was assessed by comparing the number of organisms remaining on surfaces after cleaning. In unused condition all materials, other than one enamelled steel, were equally cleanable. Stainless steel, abraded artificially or impact damaged to a similar degree as stainless steel subjected to domestic wear, retained approximately one log order less bacteria after cleaning than the other materials subjected to the same treatments. Little difference in cleanability was recorded between the abraded surfaces of the other materials although enamelled steel surfaces were less cleanable than mineral resin or polycarbonate after impact damage, because of the greater susceptibility of enamelled steel to damage by this treatment. When cleaning time was extended beyond 10 s for the abraded and impact damaged materials, their cleanability was not enhanced as compared with stainless steel. Changes in surface finish after abrasion were assessed by surface roughness measurement and scanning electron microscopy. Surfaces with poor cleanability before and after abrasion were characterized by pitting, crevices or jags. These surfaces are likely to retain more bacteria because of increased numbers of attachment sites, a larger bacterial/material surface contact area and topographical areas in which applied cleaning shear forces are reduced. Materials that resist surface changes, e.g. stainless steel, will remain more hygienic when subjected to natural wear than materials which become more readily damaged.     

横断山区东部四种林型地表甲虫的物种多样性

2001年7月8—14日在横断山区东部选择皆伐后经过管理的人工次生林(MSF)、无人管理的农耕区次生林(USF)、邻近天然的冷杉林(NAF)和杜鹃矮曲林(NRF)4种林型,共设置样地20块,以巴氏罐诱法收集地表甲虫的物种组成和数量数据,并以地表甲虫的种类和数量分布为属性做主成分分析和聚类分析,研究森林皆伐和管理行为对地表甲虫物种多样性的影响。共采集地表甲虫标本4292号,步甲科、觅葬甲科和隐翅虫科分别占总数46．8％、13．1％和11．4％,是数量最多的类群;金龟科、象甲科和拟步甲科的数量也各在5％以上,为常见类群。其中,步甲科的个体数量在NRF显著多于其他林型,在USF显著少于其他林型;觅葬甲科在两个天然林显著多于两个次生林;拟步甲科在NRF显著多于其他林型;花萤科在MSF和NAF显著多于USF;叩甲科在USF显著多于MSF和NAF;象甲科在NRF和MSF明显多于USF;叶甲科在NRF明显多于USF。地表甲虫的个体数量从USF、MSF、NAF到NRF逐渐增多,而均匀度指数则逐渐降低;MSF内物种丰富度和多样性指数分别显著高于USF和NRF。主成分分析和聚类分析表明,除了USF与其他林型有明显差异外,其他林型间有一定的相似性,但MSF与天然NAF间相似性较低。以上结果表明,森林砍伐后并种植人工林措施改变了该地区地表甲虫群落的物种分布格局,有助于恢复物种多样性。     

Open Access Meets Discoverability: Citations to Articles Posted to Academia.edu

Using matching and regression analyses, we measure the difference in citations between articles posted to Academia.edu and other articles from similar journals, controlling for field, impact factor, and other variables. Based on a sample size of 31,216 papers, we find that a paper in a median impact factor journal uploaded to Academia.edu receives 16% more citations after one year than a similar article not available online, 51% more citations after three years, and 69% after five years. We also found that articles also posted to Academia.edu had 58% more citations than articles only posted to other online venues, such as personal and departmental home pages, after five years.     

Cleanability in relation to bacterial retention on unused and abraded domestic sink materials

H olah , J.T. & T horpe , R.H. 1990. Cleanability in relation to bacterial retention on unused and abraded domestic sink materials. Journal of Applied Bacteriology 69 , 599–608.
The relative Cleanability of stainless steel, enamelled steel, mineral resin and polycarbonate domestic sink materials was assessed by comparing the number of organisms remaining on surfaces after cleaning. In unused condition all materials, other than one enamelled steel, were equally cleanable. Stainless steel, abraded artificially or impact damaged to a similar degree as stainless steel subjected to domestic wear, retained approximately one log order less bacteria after cleaning than the other materials subjected to the same treatments. Little difference in Cleanability was recorded between the abraded surfaces of the other materials although enamelled steel surfaces were less cleanable than mineral resin or polycarbonate after impact damage, because of the greater susceptibility of enamelled steel to damage by this treatment. When cleaning time was extended beyond 10 s for the abraded and impact damaged materials, their Cleanability was not enhanced as compared with stainless steel. Changes in surface finish after abrasion were assessed by surface roughness measurement and scanning electron microscopy. Surfaces with poor Cleanability before and after abrasion were characterized by pitting, crevices or jags. These surfaces are likely to retain more bacteria because of increased numbers of attachment sites, a larger bacterial/material surface contact area and topographical areas in which applied cleaning shear forces are reduced. Materials that resist surface changes, e.g. stainless steel, will remain more hygienic when subjected to natural wear than materials which become more readily damaged.     

Deoxyribonucleic Acid Repair in a Highly Radiation-Resistant Strain of Salmonella typhimurium

Deoxyribonucleic acid repair was studied in gamma-irradiated wild-type Salmonella typhimurium and in a radiation-resistant derivative 20 times more resistant than wild type. After exposure to 20 or 50 krad, the wild-type strain (DB21) degraded 30 to 50% of its prelabeled DNA into acid-soluble fragments, whereas the radioresistant strain degraded less than 15% after 4 h of incubation. Post-irradiation synthesis of DNA in the wild-type strain DB21 was reduced after a dose of 20 krad and totally inhibited after exposure to 200 krad. With radiation-resistant strain, D21R6008, on the other hand, DNA synthesis was delayed after a dose of 200 krad but not inhibited. Doses of 20 and 200 krad produced a similar number of single-strand breaks in the DNA of both strains as determined by zone sedimentation analysis in alkaline sucrose gradients. The radiation-resistant strain D21R6008, on the other hand, DNA synthesis was strand breaks in its DNA and repairs these damages more rapidly than wild-type Salmonella.     

Lanthanum as an intracellular stain for electron microscopy

Summary Results obtained after the normal aldehyde fixation of duodenal enterocytes for electron microscopy have been compared with results obtained when 0.1% Malachite Green or 10mm lanthanum chloride had been added during aldehyde fixation. Sections were examined without further staining, and after counterstaining with lead citrate and uranyl acetate. In unstained sections, lanthanum-treated material showed improved contrast when compared to results from the other two methods. Also, after counterstaining, areas showing excellent contrast were much more frequent and more readily detected in the lanthanum-treated material. In the microvilli of enterocytes fixed in the presence of lanthanum, the plasmalemma-glycocalyx was defined more clearly and the results were more pleasing subjectively. When Malachite Green was present in the fixative, good contrast was observed more frequently than in routinely fixed tissues, but less often than in those treated with lanthanum. It is suggested that the addition of lanthanum chloride or Malachite Green to the fixative may prove useful in many ultrastructural studies.     

长白山次生林演替过程中土壤动物群落的变化

通过对长白山白河局不同林龄的次生林土壤动物的组成进行比较。探讨了土壤动物群落随森林采伐更新演替的变化以及演替阶段(增长期、过渡期和稳定期)．研究表明,不同类群土壤动物的演变趋势是腐食类群数量相对较多,其变化趋势接近植被的变化规律,均是经过上升、下降,最后达到稳定;植食类群演替前期在整个群落中所占比例较高,随着演替年代的增加,比例呈下降的趋势;捕食类群经过100年左右的演替,数量明显增加;从昆虫类群组成来看,林龄较短者,未稳定的类群数较多,林龄较长者,未稳定的类群较少．     

BCG—PPD的制备及应用

用三氯醋酸(TCA)和硫酸铵(AS)综合法,由卡介菌苗(BCG)培养滤液中提纯制得卡介菌素纯蛋白衍生物(BCG—PPD)。BCG—PPD的纯度和结核菌素纯蛋白衍生物国际标准(PPD-S)及中国标准(PPD—C)相近,高于加拿大标准(PPD—CT68)和丹麦标准(PPD—RT23)。在BCG免疫豚鼠中,BCG—PPD的皮肤迟发型变态反应(DTH)大于结核菌素纯蛋白衍生物(PPD)的DTH反应。在结核菌感染豚鼠组中,BCG—PPD的DTH反应小于PPD的DTH反应.在检查333名新生儿接种BCG12周后的免疫     

Specific production of prostaglandin E by human amnion in vitro

Prostaglandin production by intra-uterine human tissues has been investigated using a method of tissue superfusion. Tissues were obtained at elective Caesarean section and after spontaneous vaginal delivery. It was found that all the tissues studied (amnion, chorion, decidua and placenta) produced more prostaglandin E (PGE) and 13,14-dihydro-15-keto-prostaglandin F (PGFM — the major circulating metabolite of prostaglandin F) than prostaglandin F (PGF). Amnion produced significantly more PGE (but not PGF or PGFM) than any other tissue. Prostaglandin production by each tissue was similar whether it was taken at elective Caesarean section or after spontaneous vaginal delivery.     

Effect of the stress of unilateral adrenalectomy on the depletion of individual cholesteryl esters in the rat adrenal

Normal rats were subjected to unilateral adrenalectomy and were killed 3 hr later. The concentration and composition of the cholesteryl esters in adrenals removed at operation and after death were compared. The esterified cholesterol concentration was lower in the adrenals obtained 3 hr after surgery. Cholesteryl arachidonate decreased in concentration significantly more than any other ester, followed in order of magnitude by linoleate and oleate. The cholesteryl ester concentration of adrenals removed from sham-operated rats 3 hr after surgery was also greatly reduced. On the basis of comparison with other work on the hydrolysis of cholesteryl esters by adrenal homogenates, it is concluded that the apparent selectivity in depletion of cholesteryl esters is due to differences in their rates of hydrolysis.     

Lignocaine Therapy for Ventricular Ectopic Activity after Acute Myocardial Infarction: A Double-blind Trial

The effectiveness of intravenous lignocaine in suppressing ventricular ectopic activity after acute myocardial infarction was examined in a double-blind trial in 82 patients. Whereas suppression of unifocal ventricular ectopics was achieved by lignocaine in 90% of patients, other forms of potentially more dangerous ectopic activity (multifocal or R-on-T ectopics) seemed more resistant to therapy. Cessation of ectopic activity was also observed in about one-third of the patients in the control group. The incidence of ventricular tachycardia and fibrillation and the mortality during and after the trial period were similar in the lignocaine-treated and control groups, whether or not the initial ventricular ectopics had been suppressed.This study provides no evidence to support the routine use of intravenous lignocaine in the management of ventricular ectopic activity after acute myocardial infarction.     

Importance of the cellular energy level for enzyme release induced by direct membrane damage

A release of intracellular enzymes may occur as a result of energy depletion of the cells or after direct membrane damage. A direct membrane damage, however, may be counteracted by the cell by energy-consuming reactions, thus more or less being dependent of the cellular energy level. Therefore, the association between enzyme release and the energy level was investigated after addition of various agents impairing the normal membrane function, i.e. lysophosphatidylcholine, phospholipases, the Ca ionophore A23187, ouabain and superoxide/H2O2, and after incubation in a hypotonic medium. It was observed that in some types of membrane damage the cellular energy is minimally involved, in other types the extent of enzyme release depends on the cellular energy level, and in some other types the cellular energy is affected but the connection to the enzyme release is not clear. The results also indicate that the effect of membrane-active agents arising in ATP-depleted states may be more severe in ATP-depleted than in normal cells.     

The effect of alcoholization on the behavioral reactions of rats in an 8-arm radial maze

The influence of 20% alcohol consumption on training of low-active rats in 8-arm radial maze was studied. One group of animals was trained before and the other group after the alcoholization. All the animals acquired the conditioned reaction in the radial maze. However, the behavioral difference between the groups consisted in spatially-motor asymmetry. The rats trained before the alcohol consumption had less stereotyped behavior and more distinctly preferred to enter the maze arms at the angle of 45 degrees than the animals trained after the alcohol consumption. After the alcohol consumption, rats more frequently refused from behavioral task performance in comparison with the animals trained after the alcoholization. The influence of alcohol consumption of learning and memory in low-active rats is discussed.     

The influence of age and experience with conspecifics on territorial behavior inDrosophila melanogaster

Drosophila melanogastermales initiated aggressive behavior toward other males and defended territories several hours after they were able to court and mate females. Males that were 3 days or more posteclosion were more successful at holding territories than younger males. Three-day-old males established territories more readily and escalated more often against territory residents than males that were 1 day old. Residents did not usually force young males from territories until they were a few hours posteclosion. The development of territorial behavior was not affected by familiarity or prior exposure to females. Males held in isolation established territories more quickly and behaved more aggressively than males held in groups. Males that previously held territories were more likely to reestablish them after a disturbance.     

Inter-annual variation of reproductive parameters and fruit availability in two populations of Japanese macaques

Among wild Japanese macaques, which have clear reproductive seasonality, correspondence between fruit-food production in the mating season and birth rate in the following year was confirmed in two different habitats. One of the study areas was evergreen broad leaved forest on Yakushima Island, for which demographic and fruiting data for seven years were used. The other was a deciduous-coniferous mixed forest on Kinkazan Island in the cool temperate zone, for which 11 years of data were used. From the fruit-crop data, each year was classified as a good or bad fruiting year for each population. At both habitats, female macaques had fewer babies after bad fruiting years than after good fruiting years. In Yakushima, small troops had a lower birth rate than large troops and this tendency was clear after bad fruiting but not after good fruiting. On the other hand, in Kinkazan such differences due to troop size were not found. These findings were consistent with the observation that intertroop encounters occur more often and are more agonistic in Yakushima than in Kinkazan and large troops tend to be dominant to small troops in the Yakushima population. Thus annual fluctuations in fruit production appear to increase the difference in birth rates between troops of different sizes through intertroop competition in Yakushima, but not in Kinkazan.