Toxic action of aqueous wheat straw extract on horse e purslane

The toxic action of aqueous wheat (Triticum aestivum) straw extracts was investigated on germination, early seedling growth, some biochemical attributes and the antioxidant enzymes of horse purslane (Trianthemaportulacastrum). Aqueous extracts of wheat straw were prepared by soaking the wheat straw in distilled water in 1:10 w/v ratio and diluted to obtain the concentrations of 0, 25, 50, 75 and 100%. These were used as pre and post emergence in laboratory and screen house trials. Wheat aqueous extracts exhibited phytotoxicity to horse purslane by inhibiting and delaying its germination and suppressing seedling growth. Wheat phytotoxins in its aqueous extracts suppressed the chlorophyll content and soluble protein, and enhanced soluble phenolics and the activity of antioxidant enzymes as catalase, peroxidase and superoxide dismutase in the seedlings of horse purslane compared with the control. Such inhibitory activity is believed to originate from exposure to wheat phytotoxins that are present in its aqueous straw extract. The suppressive effects of wheat straw need to be investigated further under field conditions.

The many faces of strikes : attitudes towards industrial action by labour, management and human resources

Strikes provide a current, fresh but also a seldom-addressed issue to study from economic sciences perspective. This study provides to filling this research gap by trying to identify attitudes towards strikes that can be found inside organizations. The research problem this study then sets out to answer is: “What kinds of attitudes exist inside organizations towards industrial actions and how attitudes vary between labour, management and human resources?” This study has been planned with a view to test how qualitative attitudinal research, as a method, is suited to studying a phenomenon such as strike. At the heart of this research approach lies an assumption linked to rhetoric social psychology, that attitude is a phenomenon that can be identified in argumentation. For this research 10 semi-structured interviews in 4 organizations were conducted utilizing statements and pictures as stimulants for discussion. The material was transcribed and analysed following the two levels, categorical and interpretive, demanded by the chosen method. Altogether five attitudes were discovered; three of them negative, one indifferent and one positive by nature. The negative attitudes of unfairness, failure and personification towards strikes represented the side of strikes that was perhaps the most anticipated, portraying the contradictions between employees and employer. The attitude of ordinariness, which portrayed indifference, and the positive attitude of change however, were more unanticipated findings. They reflect shared understanding and trust between conflict parties. The utilization of qualitative attitudinal approach to study strikes was deemed successful. The results of this study support prior literature on workplace conflicts for example in regards of the definition of conflict and typologies conflicts. In addition the multifaceted nature of strikes can be perceived as one statement supported by this study. It arises in the nature of the attitudes, the diversity of discussion themes during the interviews as well as in the extent of possible theories to apply.

Mefenpyr-diethyl action on fenoxaprop-p-ethyl detoxification in wheat varieties

Safeners protect crops against herbicide injury. The aim of this study was to examine the differential susceptibility of five wheat (Triticum aestivum) varieties to the herbicide fenoxaprop-p-ethyl, as well as the performance of mefenpyr-diethyl on minimizing herbicide injury and on lipid contents. Varieties BRS 49, CD 104, CEP 24, IAPAR 78 and Rubi were sprayed with fenoxaprop-p-ethyl (69 g ha¹), fenoxaprop-p-ethyl + mefenpyr-diethyl (69 g + 18.75 g ha-1), or mefenpyr-diethyl (18.75 g ha-1). Plants were evaluated visually for injury at 7 and 14 days after treatment (DAT). Glutathione S-transferase (GST) activity was assayed in aerial parts at 7 DAT, and lipid content was measured at 14 DAT. Varieties CEP 24, IAPAR 78 and Rubi were more tolerant to fenoxaprop-p-ethyl than BRS 49, and CD 104 rapidly recovering from the slight phytotoxicity symptoms produced by the herbicide. Mefenpyr-diethyl prevented crop injury associated with the herbicide. GST activity did not correlate directly with fenoxaprop-p-ethyl detoxification. However, lipid content was related to the susceptibility of wheat to fenoxaprop-p-ethyl treatment.

Allelopathic action of parthenium and its rhizospheric soil on maize as influenced by growing conditions

Biosynthesis and subsequent release of allelochemicals by a plant into the environment is supposed to be influenced by its growing conditions. To ascertain what will be the allelopathic action of plant parts and rhizospheric soils of parthenium (Parthenium hysterophorus) growing at various farm locations with varied growing conditions, germination and seedling growth of maize hybrid (DK 6142) were assayed by sowing its seeds in petri plates lined with filter paper and pots filled with soil. Minimum germination percentage (30.0%), germination index (2.01), germination energy (36.3), seedling length (3.3 cm), seedling biomass (10 mg) and seedling vigor index (99.0) of maize were observed in leaf extract followed by fruit and whole plant extracts of parthenium growing near the field border. Rhizospheric soil collected underneath parthenium growing near a water channel caused maximum reductions in germination index (30.8%), germination energy (40.6%), seedling length (32.6%), seedling biomass (35.1%) and seedling vigor index (34.3%) of maize compared with that soil without any vegetation. Phytotoxic inhibitory effects of both parthenium plant and rhizospheric soil were more pronounced on maize root than its shoot growth. The higher suppressive action against germination and seedling growth of maize was probably due to higher total phenolic concentrations (6678.2 and 2549.0 mg L-1) and presence of phenolic compounds viz., gallic, caffeic, 4-hydroxy-3-methoxy benzoic, p-coumaric and m-coumaric acids; and ferulic, vanillic, syringic and m-coumaric acids in aqueous leaf extract of parthenium uprooted near the field border and its rhizospheric soil collected near a water channel, respectively.

Action of laccase on mechanical softwood pulps

Träfibrernas naturliga egenskaper begränsar deras användning i många tillämpningar. Träfibrernas egenskaper kan modifieras genom att binda nya komponenter med önskade egenskaper till fiberns yta. DI Stina Grönqvist bevisade i sin avhandling att nya funktionella grupper kan bindas till ligninhaltiga träfibrer genom att aktivera ytligninet med lackasenzym. Resultaten kan utnyttjas till att förbättra de traditionella träfibrernas och fiberprodukternas egenskaper samt att hitta nya tillämpningar för träfibrerna. ”Om träfibrerna t.ex. modifieras så att de blir vattenavstötande kan de modifierade träfibrerna användas istället för plast i förpackningar” berättar Stina Grönqvist. Syftet med denna avhandling var att undersöka effekterna av lackasenzym på TMP (termomekanisk massa) och dess fraktioner. I Finland tillverkas TMP av gran och massan innehåller rikligt med lignin. När ytligninet på träfibrernas yta modifieras med hjälp av oxiderande enzymer, såsom lackas, bildas reaktiva radikaler i ligninen på fibrernas ytor. De bildade radikalerna kan utnyttjas till att binda komponenter med nya egenskaper till fiberytan. För att kunna utnyttja den fulla potentialen av den lackasbaserade modifieringsmetoden behövs mera information om så väl de faktorer som påverkar bildningen av radikaler som om mekanismerna hur de nya komponenterna binds till fibrerna ___________________________________ Puukuitujen luontaiset ominaisuudet rajoittavat niiden hyödyntämistä joissakin sovelluksissa. Ominaisuuksia voidaan kuitenkin muuttaa liittämällä kuidun pintaan uusia yhdisteitä. DI Stina Grönqvist osoitti väitöstyössään, että uusia kuitujen ominaisuuksia muuttavia funktionaalisia yhdisteitä voidaan sitoa ligniinipitoisiin puukuituihin aktivoimalla kuitujen pinnan ligniiniä lakkaasi-entsyymillä. Tutkimuksen tuloksia voidaan hyödyntää ligniinipitoisten puukuitujen ominaisuuksien parantamiseen ja jopa täysin uusien ominaisuuksien kehittämiseen. ”Jos kuituja muutetaan vettä hylkiväksi sitomalla kuituihin vettä hylkiviä yhdisteitä entsyymien avulla, voidaan puukuituja käyttää korvaamaan muovia pakkauksissa”, kertoo Stina Grönqvist. Väitöstyön kohteena oli TMP-massan eli kuumahiertämällä valmistetun mekaanisen puumassojen ja niiden fraktioiden muokkaaminen lakkaasi-entsyymillä (TMP, Thermomechanical pulp). Suomalainen TMP-massa valmistetaan kuusesta ja siinä on runsaasti muokkaamatonta ligniiniä. Kun puukuidun pinnan ligniiniä muokataan hapettavilla entsyymeillä, muodostuu kuidun pintaan reaktiivisia radikaaleja. Syntyneiden radikaalien avulla kuituihin voidaan liittää yhdisteitä, jotka antavat kuidulle uusia ominaisuuksia. Menetelmän tarjoamien mahdollisuuksien hyödyntämiseksi tarvitaan tietoa kuidun radikalisointiin ja yhdisteiden liittämiseen vaikuttavista tekijöistä.

The site of self-incompatibility action in cupuassu (Theobroma grandiflorum)

Cupuassu (Theobroma grandiflorum (Willd. ex Spreng.) Schumann) is a fruit tree that is attracting attention in Brazil and also in other tropical countries. Its pulp is used to prepare ice-cream, juices, jellies and many other home-made sweets. This species has a very low fecundity, attributed to problems with pollination and self-incompatibility, noted as being restrictive to the agronomic productivity of the species. Controlled pollinations between compatible and incompatible parents were made and flowers were collected at three times: 24, 48 and 72 h after pollinations, during the floral seasons of 1995 and 1998. In flowers collected 24 h after pollination, in both compatible and incompatible crosses, around 70% of ovules showed egg apparatus without evidences of sperm cell delivery; nevertheless some pollen tubes had been observed. Ovaries collected at 48 h showed different behaviors according to the type of cross. In the compatibles, 35% of ovules did not show evidences of gamete fusion. In incompatible crosses this number rose to 50%. Collected ovaries with 72 h, from compatible and incompatible crosses, showed respectively 1.2% and 14.2% of the ovules with the egg apparatus and polar nuclei only. In these ovaries, for the two types of crosses, the presence of sperm nuclei was common and the zygote was still undivided. The incompatibility action is occurring after fertilization, in a late self-incompatibility action.

Lead (Pb2+) and cadmium (Cd2+) inhibit the dipsogenic action of central beta-adrenergic stimulation by isoproterenol

We have previously demonstrated that acute third ventricle injections of both Pb2+ and Cd2+ impair the dipsogenic response elicited by three different situations: dehydration and central cholinergic or angiotensinergic stimulation. ß-Adrenergic activation is part of the multifactorial integrated systems operating in drinking behavior control in the central nervous system. In the present study acute third ventricle injections of Pb2+ (3, 30 and 300 pmol/rat) or Cd2+ (0.3, 3 and 30 pmol/rat) blocked the dipsogenic response induced by third ventricle injections of isoproterenol (ISO; 160 nmol/rat) in a dose-dependent manner. Normohydrated animals receiving ISO + NaAc (sodium acetate) or saline (controls) displayed a high water intake after 120 min (ISO + saline = 5.78 ± 0.54 ml/100 g; ISO + NaAc = 6.00 ± 0.6 ml/100 g). After the same period, animals receiving ISO but pretreated with PbAc at the highest dose employed (300 pmol/rat) drank 0.78 ± 0.23 ml/100 g while those receiving ISO and pretreated with the highest dose of CdCl2 (30 pmol/rat) presented a water intake of 0.7 ± 0.30 ml/100 g. Third ventricle injections of CdCl2 (3 nmol/rat) or PbAc (3 nmol/rat) did not modify food intake in rats deprived of food for 24 h. Thus, general central nervous system depression explaining the antidipsogenic action of the metals can be safely excluded. It is concluded that both Pb2+ and Cd2+ inhibit water intake induced by central ß-adrenergic stimulation

Participation of kinins in the inhibitory action of captopril on acute hypertension induced by L-NAME in anesthetized rats

The aim of the present study was to investigate the role of bradykinin in the inhibitory action of captopril in hypertension induced by L-NAME in anesthetized rats. Male Wistar rats (260-320 g) were anesthetized with chloralose and arterial blood pressure was recorded with a polygraph pressure transducer. The hypertensive effect of L-NAME was studied in rats pretreated with saline, captopril or HOE 140 plus captopril. The effect of captopril was also studied during the sustained pressor effect of L-NAME. The acute pressor effect of L-NAME (10 mg/kg, iv) was significantly reduced by iv pretreatment with 2 mg/kg captopril (D increase of 49 ± 4.9 mmHg reduced to 20 ± 5.4 mmHg, P = 0.01). The pressor effect of L-NAME (D increase of 38 ± 4.8 mmHg) observed in rats pretreated with captopril and HOE 140 (0.1 mg/kg, iv) was not significantly different from that induced by L-NAME in rats pretreated with saline (P = 0.09). During the sustained pressor effect induced by L-NAME (D increase of 49 ± 4.9 mmHg) captopril induced a significant (P<0.05) reduction in arterial blood pressure (D decrease of 22 ± 3.0 mmHg). The present results demonstrate that the acute pressor effect of L-NAME is reduced by captopril and this inhibitory effect may be partly dependent on the potentiation of the vasodilator actions of bradykinin

Collective Action in Commons: Its Diverse Ends and Consequences

Collective Action in Commons: Its Diverse Ends and Consequences explores new ways in which collective action theories can contribute to our understanding of natural resource management, especially the management of common-pools. Combining classical collective action theories and lessons from earlier empirical works, the study shows that cooperation among resource users is not only a possible solution to “the tragedy of the commons”, but it can be a part of the problem as well. That is, successful cooperation may increase the likelihood of resource depletion, for example, through more effective resource utilization or collusion against sanctioning and monitoring systems. The study also explores how analytic narratives can be used to tell the story behind problems of resource use and their solutions, including the diverse roles of cooperation.

Fibrinolytic action on fresh human clots of whole body extracts and two semipurified fractions from Lonomia achelous caterpillar

The severe bleeding diathesis produced by intoxication with the venom of Lonomia achelous caterpillars is characterized by prolonged bleeding from superficial skin wounds as well as massive hemorrhage into body cavities. The aim of the present study was to evaluate the effect of the crude venom and its fibrinolytic fractions on in vitro lysis of whole blood clots. Venom fractions with fibrinolytic activity were obtained by gel filtration chromatography on Sephadex G75 using imidazole buffer, pH 7.4, at a flow rate of 24 ml/h. Four peaks with fibrinolytic activity were obtained by this method. The highest activity was found in the first two peaks (both peaks were used for the experiments). The results show that the caterpillar venom degraded the preformed clots at a slower rate than plasmin. In addition, plasma protease inhibitors of the fibrinolytic system (a2-antiplasmin, a2-macroglobulin, PAI, etc.) only weakly inhibited the lytic effect of the caterpillar venom. These characteristics, as well as the pattern of fibrinogen degradation products, the delay period on fibrin plate lysis and amidolytic activity on chromogenic substrate, reported previously, indicate that the caterpillar enzymes are different from plasmin and trypsin.

Toxic, antimicrobial and hemagglutinating activities of the purple fluid of the sea hare Aplysia dactylomela Rang, 1828

The antimicrobial, hemagglutinating and toxic activities of the purple fluid of the sea hare Aplysia dactylomela are described. Intact or dialyzed purple fluid inhibited the growth of species of Gram-positive and Gram-negative bacteria and the action was not bactericidal but bacteriostatic. The active factor or factors were heat labile and sensitive to extreme pH values. The fluid preferentially agglutinated rabbit erythrocytes and, to a lesser extent, human blood cells, and this activity was inhibited by the glycoprotein fetuin, a fact suggesting the presence of a lectin. The fluid was also toxic to brine shrimp nauplii (LD50 141.25 µg protein/ml) and to mice injected intraperitoneally (LD50 201.8 ± 8.6 mg protein/kg), in a dose-dependent fashion. These toxic activities were abolished when the fluid was heated. Taken together, the data suggest that the activities of the purple fluid are due primarily to substance(s) of a protein nature which may be involved in the chemical defense mechanism of this sea hare.

Blockade of the action of nitric oxide in human septic shock increases systemic vascular resistance and has detrimental effects on pulmonary function after a short infusion of methylene blue

To investigate the role of nitric oxide in human sepsis, ten patients with severe septic shock requiring vasoactive drug therapy and mechanical ventilation were enrolled in a prospective, open, non-randomized clinical trial to study the acute effects of methylene blue, an inhibitor of guanylate cyclase. Hemodynamic and metabolic variables were measured before and 20, 40, 60, and 120 min after the start of a 1-h intravenous infusion of 4 mg/kg of methylene blue. Methylene blue administration caused a progressive increase in mean arterial pressure (60 [55-70] to 70 [65-100] mmHg, median [25-75th percentiles]; P<0.05), systemic vascular resistance index (649 [479-1084] to 1066 [585-1356] dyne s-1 cm-5 m-2; P<0.05) and the left ventricular stroke work index (35 [27-47] to 38 [32-56] g m-1 m-2; P<0.05) from baseline to 60 min. The pulmonary vascular resistance index increased from 150 [83-207] to 186 [121-367] dyne s-1 cm-5 m-2 after 20 min (P<0.05). Mixed venous saturation decreased from 65 [56-76] to 63 [55-69]% (P<0.05) after 60 min. The PaO2/FiO2 ratio decreased from 168 [131-215] to 132 [109-156] mmHg (P<0.05) after 40 min. Arterial lactate concentration decreased from 5.1 ± 2.9 to 4.5 ± 2.1 mmol/l, mean ± SD (P<0.05) after 60 min. Heart rate, cardiac filling pressures, cardiac output, oxygen delivery and consumption did not change. Methylene blue administration was safe and no adverse effect was observed. In severe human septic shock, a short infusion of methylene blue increases systemic vascular resistance and may improve myocardial function. Although there was a reduction in blood lactate concentration, this was not explained by an improvement in tissue oxygenation, since overall oxygen availability did not change. However, there was a significant increase in pulmonary vascular tone and a deterioration in gas exchange. Further studies are needed to demonstrate if nitric oxide blockade with methylene blue can be safe for patients with septic shock and, particularly, if it has an effect on pulmonary function.

Carte spéciale des colonies où se porte actuellement l'action française: publiée sous les auspices de la Société de Géographie de l'Est

Kartta kuuluu A. E. Nordenskiöldin kokoelmaan

Effects of terpineol on the compound action potential of the rat sciatic nerve

Terpineol, a volatile terpenoid alcohol of low toxicity, is widely used in the perfumery industry. It is an important chemical constituent of the essential oil of many plants with widespread applications in folk medicine and in aromatherapy. The effects of terpineol on the compound action potential (CAP) of rat sciatic nerve were studied. Terpineol induced a dose-dependent blockade of the CAP. At 100 µM, terpineol had no demonstrable effect. At 300 µM terpineol, peak-to-peak amplitude and conduction velocity of CAP were significantly reduced at the end of 180-min exposure of the nerve to the drug, from 3.28 ± 0.22 mV and 33.5 ± 7.05 m/s, respectively, to 1.91 ± 0.51 mV and 26.2 ± 4.55 m/s. At 600 µM, terpineol significantly reduced peak-to-peak amplitude and conduction velocity from 2.97 ± 0.55 mV and 32.8 ± 3.91 m/s to 0.24 ± 0.23 mV and 2.72 ± 2.72 m/s, respectively (N = 5). All these effects developed slowly and were reversible upon 180-min washout.