Weed community and growth under the canopy of trees adapted to the brazilian semi-arid region

The objectives of this work were to evaluate the floristic composition and dry biomass of weeds under the canopy of seven perennial species adapted to the Semi-Arid region of Brazil, and correlate these characteristics with growth traits of the perennial species. The following perennial species were evaluated in two experiments (E1 and E2): mesquite (Prosopis juliflora), jucá (Caesalpinia ferrea), white popinac (Leucaena leucocephala), mofumbo (Combretum leprosum), neem (Azadirachata indica), sabiá (Mimosa caesalpiniaefolia) and tamarind (Tamarindus indica). In E1, the seven species were evaluated in a random block design with four replicates and nine plants per plot. In E2, evaluation comprised four species (mesquite, jucá, white popinac, and tamarind) in a random block design with eight replicates and nine plants per plot. A circle with an area of 1.77 m² was established around the trunk of each plant, two years after they were transplanted to the permanent location. The weeds collected within this circle were cut even with the ground, classified and weighed. At this time, plant height, and crown and stem diameters were evaluated in all trees of each plot. In E1 there were no differences between tree species as to weed frequency under their canopies; however, weed growth was smaller under the canopy of sabiá trees. Mesquite and sabiá had the greatest plant height and crown diameter means, but only sabiá had the greatest stem diameter. In E2, the perennial species were not different with regard to weed frequency and growth under their canopies, but mesquite had the greatest growth, as measured by plant height (with significant results for jucá as well) and crown and stem diameter.

Trinexapac-Ethyl and Sulfometuron-Methyl Selectivity to Young Eucalyptus Plants

Trinexapac-ethyl and sulfometuron-methyl are the most widely used ripeners in sugarcane. The application is performed by airborne spraying. Thus, if weather conditions are unfavorable, spray drift to neighboring areas may occur. The objective of this study was to assess the selectivity of the plant growth regulators trinexapac-ethyl and sulfometuron-methyl, used as sugarcane ripeners, to eucalyptus (Eucalyptus urograndis) young plants. The experiment was installed in an eucalyptus commercial yield area, in the municipality of Tambaú, state of São Paulo, Brazil, and arranged in a 2 x 8 factorial design in randomized blocks with four replications. The treatments studied were trinexapac-ethyl and sulfometuron-methyl, sprayed in eight doses, 0; 1.0; 2.5; 5.0; 10; 25; 50 and 100% of the dose used in sugarcane as ripeners (200 g ha-1 of trinexapac-ethyl and 15 g ha-1 of sulfometuron-methyl). Chemical ripeners were applied on eucalyptus plants with 48 cm in height on average; 10.1 branches; 4.5 mm of stem diameter and 44.3 cm of crown diameter, at 46 days after seeding. Trinexapac-ethyl was selective to eucalyptus and stimulated crown diameter growth. At higher doses, sulfometuron-methyl promoted severe noticeable injuries in eucalyptus plants, such as apical bud death. However, during the assessment period the plants recovered and the visual symptoms of phytotoxicity and growth alterations were not observed at 60 days after application. The plant growth regulators trinexapac-ethyl and sulfometuron-methyl were selective to eucalyptus young plants.

Juvenile dynamics of the endemic and rare Enterolobium glaziovii Benth. (Mimosaceae) around reproductive trees in the Atlantic forest, Brazil

Studies on the regeneration and seedling mortality of rare tree species are important, but scarce. The aim of this study was to investigate the annual variation in recruitment, growth and mortality of juveniles of Enterolobium glaziovii Benth., a rare tree species from the Brazilian Atlantic Rain Forest. All seedlings and juveniles around four reproductive trees were labeled and their fate was followed from 1996 to 1999. There were no annual differences in juveniles' recruitment below and beyond the parental crown, but juveniles' survival and growth were lower below than beyond of the parental tree crowns. Small individuals (< 15 cm tall) showed the greatest mortality and the lowest growth, followed by medium (from 15 to 50 cm tall) and large ones (> 50 cm tall). Large juveniles were more widely dispersed from the conspecific parental tree than were medium and small ones. This suggests that distance dependent mortality of juveniles mediated by the parental tree is an important cause of spacing shifts associated with the growth of small individuals of E. glaziovii into large ones. Widely dispersed juveniles may escape the high mortality associated with pathogens, herbivores or seed predators concentrated around adult conspecifics. The negative influence of the parental tree on its juveniles may explain the sparse distribution of its adults in the forest.

Frugivory on Margaritaria nobilis L.f. (Euphorbiaceae): poor investment and mimetism

Dehiscent fruits of Euphorbiaceae usually have two stages of seed dispersal, autochory followed by myrmecochory. Two stages of Margaritaria nobilis seed dispersal were described, the first stage autochoric followed by ornithocoric. Their dehiscent fruits are green and after they detached from the tree crown and fall on the ground, they open and expose blue metallic cocas. We studied the seed dispersal system of Margaritaria nobilis in a semi-deciduous forest in Brazil. In 80 h of focal observations, we recorded only 12 visits of frugivores, however the thrush Turdus leucomelas was the only frugivore that swallowed the fruits on the tree crown. Pitylus fuliginosus (Fringilidae) and Pionus maximiliani (Psittacidae) were mainly pulp eaters, dropping the seeds below the tree. On the forest floor, after fruits dehiscence, jays (Cyanocorax chrysops), guans (Penelope superciliaris), doves (Geotrygon montana) and collared-peccaries (Pecari tajacu) were observed eating the blue diaspores of M. nobilis. Experiments in captivity showed that scaly-headed parrots (Pionus maximiliani), toco toucans (Ramphastos toco), jays (Cyanochorax chrysops), and guans (Penelope superciliaris) consumed the fruits and did not prey on the seeds before consumption. The seeds collected from the feces did not germinate in spite of the high viability. The two stages of seed dispersal in M. nobilis resembles the dispersal strategies of some mimetic species. However M. nobilis seeds are associated with an endocarp, it showed low investment in nutrients, and consistent with this hypothesis, M. nobilis shared important characteristics with mimetic fruits, such as bright color display, long seed dormancy and protection by secondary compounds.

Dinâmica espaço-temporal de Melocactus ernestii subsp. ernestii (Cactaceae) no Nordeste do Brasil

Melocactus ernestii Vaupel subsp. ernestii ocorre em afloramentos rochosos descontínuos no leste do Brasil. O presente estudo investigou o padrão espaço-temporal dos eventos de mortalidade e sobrevivência de plântulas da M. ernestii e a relação com as plantas perenes, a partir da utilização de parcelas, alocadas com auxílio de trenas, onde foram tomadas as coordenadas cartesianas do centróide dos estádios de desenvolvimento, com posterior análises de padrões de ponto baseado na função K de Ripley. Foram mapeados nas parcelas 686 indivíduos da M. ernestii. O padrão espacial variou em função da escala, do estádio de desenvolvimento e do grau de intemperização dos afloramentos. Os eventos de recrutamento e mortalidade foram espacialmente estruturados e influenciados por pulsos de precipitação sazonais. As plântulas emergiram a ca. 50 cm do centróide dos adultos. Das 136 plântulas monitoradas em 18 meses, 84% morreram. Os resultados mostraram que microsítios inicialmente eficazes na manutenção de sementes e promotores da germinação não necessariamente podem ser eficazes para o estabelecimento das plântulas. A magnitude das interações bióticas em ambientes estressantes é espécie-específica e indica que associação positiva entre plantas adultas e sobrevivência de plântulas não é consistente com o tempo. Este tipo de modelagem populacional permite melhor compreensão sobre o papel das interações positivas e negativas como forças estruturadoras de comunidades e pode ajudar a entender a complexidade das interações bióticas em gradientes ambientais severos.

The radioprotective effect of a new aminothiol (20-PRA)

We examined the radioprotective effect of aminothiol 2-N-propylamine-cyclo-hexanethiol (20-PRA) on a human leukemic cell line (K562) following various radiation doses (5, 7.5 and 20 Gy) using a source of 60Co g-rays. At 5 Gy and 1 nM 20-PRA, a substantial protective effect (58%) was seen 24 h after irradiation, followed by a decrease at 48 h (11%). At the high radiation dose (20 Gy) a low protective effect was also seen (35%). In addition, the antitumorigenic potential of 10 nM 20-PRA was shown by the inhibition of crown gall formation induced by Agrobacterium tumefaciens. The radioprotective potency of 20-PRA is 105-106 times higher than that of the aminothiol WR-1065 (N-(2-mercaptoethyl)-1,3-diaminopropane) whose protective effect is in the 0.1 to 1.0 mM range.

Calcium antagonism and the vasorelaxation of the rat aorta induced by rotundifolone

The vasorelaxing activity of rotundifolone (ROT), a major constituent (63.5%) of the essential oil of Mentha x villosa, was tested in male Wistar rats (300-350 g). In isolated rat aortic rings, increasing ROT concentrations (0.3, 1, 10, 100, 300, and 500 µg/ml) inhibited the contractile effects of 1 µM phenylephrine and of 80 or 30 mM KCl (IC50 values, reported as means ± SEM = 184 ± 6, 185 ± 3 and 188 ± 19 µg/ml, N = 6, respectively). In aortic rings pre-contracted with 1 µM phenylephrine, the smooth muscle-relaxant activity of ROT was inhibited by removal of the vascular endothelium (IC50 value = 235 ± 7 µg/ml, N = 6). Furthermore, ROT inhibited (pD2 = 6.04, N = 6) the CaCl2-induced contraction in depolarizing medium in a concentration-dependent manner. In Ca2+-free solution, ROT inhibited 1 µM phenylephrine-induced contraction in a concentration-dependent manner and did not modify the phasic contractile response evoked by caffeine (20 mM). In conclusion, in the present study we have shown that ROT produces an endothelium-independent vasorelaxing effect in the rat aorta. The results further indicated that in the rat aorta ROT is able to induce vasorelaxation, at least in part, by inhibiting both: a) voltage-dependent Ca² channels, and b) intracellular Ca2+ release selectively due to inositol 1,4,5-triphosphate activation. Additional studies are required to elucidate the mechanisms underlying ROT-induced relaxation.

Mielen mysteereitä : regressio hypnoterapiassa

Kirjallisuusarvostelu

Yleispiirteinen kartta Iin pitäjästä

Kartan esitystekniikka: maastokartta.

Ilmeisen sietämätön vetovoima

Kirjallisuusarvostelu

Comparing the alternative utilization method for coconut in Nzema, Ghana

There are many opportunities to utilise coconut in Nzema to support farmers. Coconut oil that is mainly used for food preparation in Nzema can be utilized as fuel to support overcoming of the energy crisis in the Ghana. Coconut oil in Nzema is not used in both transportation and electricity generation. A few of the waste husk and shell are mainly used as fuel in homes for heating but greater amount is left to rot or burn the coconut plantation. In addition, some portion of the granulated coconut kernel is sometime used as feed for piggery feed and the rest of the granulated kernel are left as waste on the oil processing site. In this thesis, the author identified alternative utilization of cocoanut, for instance the use of coconut husk and shell for charcoal production, and the use of coconut trunks as construction materials. It is envisaged that exploring these alternatives will not only reduce carbon emission in the country but will also contribute significantly to the sustainability of the local agro-industry.

Use of airborne laser scanner data in demanding forest conditions

Most of the applications of airborne laser scanner data to forestry require that the point cloud be normalized, i.e., each point represents height from the ground instead of elevation. To normalize the point cloud, a digital terrain model (DTM), which is derived from the ground returns in the point cloud, is employed. Unfortunately, extracting accurate DTMs from airborne laser scanner data is a challenging task, especially in tropical forests where the canopy is normally very thick (partially closed), leading to a situation in which only a limited number of laser pulses reach the ground. Therefore, robust algorithms for extracting accurate DTMs in low-ground-point-densitysituations are needed in order to realize the full potential of airborne laser scanner data to forestry. The objective of this thesis is to develop algorithms for processing airborne laser scanner data in order to: (1) extract DTMs in demanding forest conditions (complex terrain and low number of ground points) for applications in forestry; (2) estimate canopy base height (CBH) for forest fire behavior modeling; and (3) assess the robustness of LiDAR-based high-resolution biomass estimation models against different field plot designs. Here, the aim is to find out if field plot data gathered by professional foresters can be combined with field plot data gathered by professionally trained community foresters and used in LiDAR-based high-resolution biomass estimation modeling without affecting prediction performance. The question of interest in this case is whether or not the local forest communities can achieve the level technical proficiency required for accurate forest monitoring. The algorithms for extracting DTMs from LiDAR point clouds presented in this thesis address the challenges of extracting DTMs in low-ground-point situations and in complex terrain while the algorithm for CBH estimation addresses the challenge of variations in the distribution of points in the LiDAR point cloud caused by things like variations in tree species and season of data acquisition. These algorithms are adaptive (with respect to point cloud characteristics) and exhibit a high degree of tolerance to variations in the density and distribution of points in the LiDAR point cloud. Results of comparison with existing DTM extraction algorithms showed that DTM extraction algorithms proposed in this thesis performed better with respect to accuracy of estimating tree heights from airborne laser scanner data. On the other hand, the proposed DTM extraction algorithms, being mostly based on trend surface interpolation, can not retain small artifacts in the terrain (e.g., bumps, small hills and depressions). Therefore, the DTMs generated by these algorithms are only suitable for forestry applications where the primary objective is to estimate tree heights from normalized airborne laser scanner data. On the other hand, the algorithm for estimating CBH proposed in this thesis is based on the idea of moving voxel in which gaps (openings in the canopy) which act as fuel breaks are located and their height is estimated. Test results showed a slight improvement in CBH estimation accuracy over existing CBH estimation methods which are based on height percentiles in the airborne laser scanner data. However, being based on the idea of moving voxel, this algorithm has one main advantage over existing CBH estimation methods in the context of forest fire modeling: it has great potential in providing information about vertical fuel continuity. This information can be used to create vertical fuel continuity maps which can provide more realistic information on the risk of crown fires compared to CBH.

Sensibility of the PCR technique in the detection of Stenocarpella sp. associated with maize seeds

Maize seeds, infected by Stenocarpella species, are important sources of inoculum for the introduction and dissemination of stalk and ear rot and macrospore leaf spot diseases. The use of healthy seeds is an important strategy for the preventive control of these diseases. However, one of the difficulties in the health quality control programs for maize seeds is the availability of a reliable and quick method for detecting these fungi during routine seed analyses. Therefore, the objective of the present study was to investigate the possibility of using the PCR technique as an alternative method for accurately detecting these pathogens in maize seed samples. Maize seeds were kept in contact with S. maydis colonie developed in PDA media containing mannitol at -1.4 MPa for 72 h. The seed samples used in this study were prepared with infected seeds at incidences of 100, 20, 10, 2, 1 and zero %.The primers used were able to detect S. maydis fungi in association with seeds with a maximum of 2% , however those primers were not able to differentiate between the two species.

Recueil de pièces en vers et en prose du XVIe siècle, à savoir.

Contient : 1 « Definition d'amour », par « S[AINT] G»[ELAIS] ; 2 « Rondeau », par « S[AINT] G»[ELAIS] (fol. 2). Refrain : « Mal ou bien » ; 3 « Le Courtisant » [par BALTHASARD DE CASTIGLIONE] ; 4 « Epistre » ; 5 Épigramme contre le duc de Guise et le cardinal de Lorraine ; 6 « Epistre de J[ACQUES] C»[OLIN] ; 7 « Epistre du chevalier navré et prins devant Pavie à sa dame negligente de luy escribre » ; 8 « Epistre » ; 9 « Epistre » ; 10 « Compte d'amour fugitif, translaté de grec en latin par POLITIAN, et de latin en françois par CLEMENT MAROT » ; 11 « Six Dames de Paris à Clement Marot », épître, par « JANNE DEMONT » ; 12 « Epistre de CLEMENT MAROT à trois sortes de dames parisiennes » ; 13 « A six dames, Dieu sçait quelles, qui luy envoierent une epistre pleine de ce qu'elles sçavent dire », par le même ; 14 « A celles de qui ledict MAROT ne vouldroit perdre la grace » — Commençant (fol. 60) par: Et vous aultres bien saiges... » ; 15 « CLEMENT MAROT aux gentilz veaulx « Qui ont faict les adieux nouveaulx » ; 16 Huit rondeaux, par « C[LEMENT] M»[AROT]. Refrains ; 1 « Au temps passé » ; 2 « Avant mes jours » ; 3 « En la baisant » ; 4 « Toutes les nuictz » ; 5 « S'il est ainsy » ; 6 « D'avoir le pris » ; 7 « Tout à par soy » ; 8 « De nuict » ; 17 « Dixain », par « C[LEMENT] M»[AROT] ; 18 Cinq rondeaux, par « J[ACQUES] C»[OLIN]. Refrains ; 1 « Je le voy bien » ; 2 « Quand j'ay voulu » ; 3 « Taire ou cryer » ; 4 « En me taisant » ; 5 « Incontinent » ; 19 Sept rondeaux, par « J. G ». Refrains ; 1 « De m'acquiter » ; 2 « Sy ne revient » ; 3 « Si longuement » ; 4 « L'honesteté » ; 5 « Tout vient de Dieu » ; 6 « Oultre mon gré » ; 7 « De ton ennuyt » ; 20 Cinq rondeaux, par « J[EAN] MA»[ROT]. Refrains ; 1 « Contre le coup » ; 2 « Plus chault que feu » ; 3 « Dont vient cela » ; 4 « D'un seul regard » ; 5 « Pour le deduyt » ; 21 Quatorze rondeaux. Refrains ; 1 « Au feu d'amours » ; 2 « Aupres du vif » ; 3 « Comme ung phoenix » ; 4 « Mort ou mercy » ; 5 « Faict ou failly » ; 6 « Sy mieulx ne vient » ; 7 « De grise teste » ; 8 « D'estre amoureux » ; 9 « A ma requeste » ; 10 « Je n'en veuls point » ; 11 « Au tour de vous » ; 12 « Maulgré moy » ; 13 « Quand je vous voy » ; 14 « Ung jour » ; 22 « Dixain » ; 23 Trois stances amoureuses sur les mêmes rimes ; 24 « Dixain » ; 25 « Huittain » ; 26 Deux quatrains, par « L[A] M»[AISONNEUVE] ; 27 Huitain ; 28 Deux quatrains ; 29 Deux huitains ; 30 Deux huitains ; 31 « Epitaphe » ; 32 Deux huitains ; 33 Huitain ; 34 Deux huitains ; 35 Huitain ; 36 « La Royne de Navarre, du dieu Cupido » ; 37 « Dixain » ; 38 « Complaincte fort lugubre » ; 39 « In amorem furem », épigramme latine ; 40 Traduction de l'épigramme précédente, par « STROSIUS, poeta ferrariensis » ; 41 « AUSONIUS e greco », texte latin et « translat » de l'épigramme suivante ; 42 Trois quatrains amoureux, par « le roy » [FRANÇOIS Ier] ; 43 « Dixain » ; 44 Pièce de vers de « CHAP»[UIS] ; 45 Epigramme sur « les Blancs Manteauls » ; 46 « Response » de « MAROT » à l'épigramme précédente ; 47 Deux huitains ; 48 « Response » aux huitains précédents ; 49 Rondeau, par « CHAP»[UIS]. Refrain : « Che foeu » ; 50 Deux rondeaux. Refrains ; 51 Rondeau, par [LA] « M[AISON] N»[EUVE]. Refrain ; 52 Rondeau (fol. 97). Refrain : « En bone foy » ; 53 Dixain « pour les dames de la rue S. Antoine », par « S[AINT] G»[ELAIS] ; 54 En envoyant un portrait, par « H. J. » ; 55 Huitain, par « CHAP»[UIS] ; 56 Vers sur l'«amour », par « S[AINT] G»[ELAIS] ; 57 Deux quatrains, par « COLIN » ; 58 Quatrain, par « CHAP»[UIS] ; 59 « Rondeau » (fol. 100). Refrain : « A Dieu » ; 60 Dixain ; 61 Huitain ; 62 Dixain, par [LA] « M[AISON] N»[EUVE] ; 63 Trois sixains, par « CHAP»[UIS] ; 64 Douzain, par « le roy » [FRANÇOIS Ier] et « CHAP»[UIS] ; 65 Dixain, par « S[AINT] G»[ELAIS] ; 66 Vers sur une « amitié... decousue », par « S[AINT] G»[ELAIS] ; 67 Deux quatrains, par « C[LAUDE] C»[OLLET] ; 68 Quatrain, par « CHAP»[UIS] ; 69 « Blason de couleurs », par « BRO»[DEAU] ; 70 Huitain, par « S[AINT] G»[ELAIS] ; 71 « Enigme » ; 72 Huitain, par « CHAP»[UIS] ; 73 Dixain, par « CHAP»[UIS] ; 74 Plainte d'amour, par « CHAP»[UIS] ; 75 ; 76 « Dixain », par « CHAP»[UIS] ; 77 « Response d[e] MACAULT » ; 78 Dixain ; 79 « Dixain », par « CHAP»[UIS] ; 80 Huitain, par « CHAP»[UIS] ; 81 « Dixain », par « CHAP»[UIS] ; 82 Huitain, par « S»[AINT-GELAIS] ; 83 Dixain, par « CHAP»[UIS] ; 84 Sept vers d'amour, par « CHAP»[UIS] ; 85 A une dame qui avait mêlé sa voix au son du luth de « SAINCT GELAIS » ; 86 Huitain, par « M. T. » ; 87 Huitain, par « M. T. » ; 88 Dixain, par « T. » ; 89 Huitain, par « T. » ; 90 Huitain, par « T. » ; 91 Dixain, par « le roy » [FRANÇOIS Ier] ; 92 « Rithme françoise tirée d'un epigramme latin de JONI PONTAN » ; 93 Huitain, par « CHAP»[UIS] ; 94 Dixain ; 95 Dixain, par « CHAP»[UIS] ; 96 Dixain, par « S[AINT] G»[ELAIS] ; 97 « Envoy » ; 98 Huitain, par « LA M»[AISONNEUVE] ; 99 Dixain, par « GHAP»[UIS] ; 100 Dixain ; 101 Neuf vers d'amour, par « CHAP»[UIS] ; 102 Cinq quatrains d'amour ; 103 Huitain, par « CHAP»[UIS] ; 104 Dixain, par « CHAP»[UIS] ; 105 Sept vers d'amour, par « CHAP»[UIS] ; 106 « Pour monsieur de S. », dixain ; 107 Huitain ; 108 « Response » ; 109 Dixain ; 110 Dixain « du roy » [FRANÇOIS Ier] ; 111 Unzain « d'une qui allumat le foeu de la S. Jehan » ; 112 Douzain « de monseigneur le cardinal DE TOURNON » ; 113 Quatrain, par « M. D. L. »

A fast atom bombardment mass spectrometry study of tris (3, 6-dioxaheptyl) amine-alkali metal halide complexes and hydrogen bonded complexes

The objective of this thesis was to demonstrate the potential of fast atom bombardment mass spectrometry (FABMS) as a probe of condensed phase systems and its possible uses for the study of hydrogen bonding. FABMS was used to study three different systems. The first study was aimed at investigating the selectivity of the ligand tris(3,6-dioxaheptyl) amine (tdoha) for the alkali metal cations. FABMS results correlated well with infrared and nmr data. Systems where a crown ether competed with tdoha for a given alkali metal cation were also investigated by fast atom bombardment. The results were found to correlate with the cation affinity of tdoha and the ability of the crown ether to bind the cation. In the second and third studies, H-bonded systems were investigated. The imidazole-electron donor complexes were investigated and FABMS results showed the expected H-bond strength of the respective complexes. The effects of concentration, liquid matrix, water content, deuterium exchange, and pre-ionization of the complex were also investigated. In the third system investigated, the abundance of the diphenyl sulfone-ammonium salt complexes (presumably H-bonded) in the FABMS spectrum were found to correlate with qualitative considerations such as steric hindrance and strength of ion pairs.