Crappie fisheries in northwest Mississippi flood control reservoirs are valued from social and economic standpoints. To mitigate variable recruitment rates of these recreationally valuable species, I sought to gain a better understanding of the population dynamics of these fish during their first year of life. My analyses indicate that embayment habitats in the study reservoirs display a longitudinal distribution gradient of both habitat composition and age-0 crappie abundance during late summer. Additionally, age-0 crappies inhabiting uplake floodplain areas grow to a larger size than downlake embayment-inhabiting conspecifics. The results from this study provide direction on potential management strategies to promote annual recruitment of age-0 crappies in these reservoirs.

Carbon-carbon bond formation reactions catalyzed by transition metals represent one of the most versatile and efficient strategies in organic synthesis. The catalytic transformations contribute to the development of methodologies that are more environmentally benign and with high atomic economy. Despite the progress in this field in recent years, the development of new and more efficient strategies of synthesis continues to be one of the main challenges of organic chemistry. In the present PhD thesis the Rh(I)-catalyzed [2+2+2] cycloaddition reaction of different macrocyclic and acyclic substrates containing double and/or triple bond in their structure are studied. On the other hand, Matsuda-Heck reactions and Suzuki-Miyaura cross-couplings using diazonium salts as electrophiles under Pd(II) catalysis with mild reaction conditions and a totally aqueous medium have been studied. Palladium-catalyzed carbon-carbon bonds a good alternative both in terms of cost and activity is the use of nickel catalysts. Finally, new Ni(0) complexes with macrocyclic and open-chain ligands containing double and triple bonds have been synthesized and completely characterized. Their activity in Suzuki cross-coupling reactions is then studied. / Les reaccions de formació d’enllaços carboni-carboni catalitzades per metalls de transició representen una de les estratègies més versàtils i eficients en síntesi orgànica. Les transformacions catalítiques contribueixen al desenvolupament de metodologies més benignes amb el mediambient i proporcionen una elevada economia atòmica. Encara que siguin molts els avenços fets en aquest camp en els últims anys, el desenvolupament de noves i més eficients estratègies de síntesi segueixen essent un dels reptes principals de la química orgànica. En la present tesi s'ha estudiat la reacció de cicloaddició [2+2+2] catalitzada per Rh(I) de diferents substrats macrocíclics i acíclics contenint dobles i/o triples enllaços. Per altra banda, s’han portat a terme reaccions de Matsuda-Heck i acoblaments creuats de Suzuki-Miyaura utilitzant sals de diazoni com a electròfils sota catàlisi per Pd(II) emprant condicions suaus de reacció i en medi totalment aquós. Una bona alternativa al pal•ladi en termes econòmics i d’activitat és l’ús de catalitzadors de níquel. Finalment s’han sintetitzat i caracteritzat estructuralment nous complexos de Ni(0) amb lligands macrocíclics i de cadena oberta contenint diferents insaturacions i s'ha estudiat la seva activitat catalítica en reaccions de Suzuki.

<p>Predmet izučavanja ove disertacije je ispitivanje mogućnosti&nbsp; primene stabilisanog nano Fe(0)&nbsp; i &bdquo;zelenom&ldquo; sintezom produkovanog nano&nbsp; Fe(0)&nbsp; u uklanjanju Cr(VI), Cd(II), Cu(II), Ni(II), Pb(II) i As(III)&nbsp; iz vode.&nbsp; Sinteza nano Fe(0) za stabilizaciju izvr&scaron;ena je konvencionalnom metodom&nbsp; redukcije gvožđa sa natrijum borhidridom&nbsp; u prisustvu materijala za stabilizaciju: kaolinita,&nbsp; bentonita i karboksimetil celuloze. Za &bdquo;zelenu&rdquo; sintezu nano Fe(0) kori&scaron;ćeno je li&scaron;će drveća: hrasta, duda i vi&scaron;nje.&nbsp; Karakterizacija&nbsp; dobijenih nanomaterijala izvr&scaron;ena je transmisionom i skenirajućom elektronskom mikroskopijom. Rezultati karakterizacije su pokazali da se tokom sinteze nano Fe(0) natrijum borhidridom i stabilizacije kaolinitom, bentonitom i karboksimetil celulozom, formiraju nano čestice Fe(0) veličine 20 do 90 nm, dok su veličine čestica nano Fe(0) sintetisanih &bdquo;zelenom&ldquo; metodom iznosile 10-30 nm i okarakterisane su kao nano čestice sfernog oblika, različitih veličina bez značajane aglomeracije.&nbsp; Primena nano&nbsp;Fe(0) na efikasnost&nbsp; uklanjanja metala iz vode ispitivana je pri različitim uslovima:&nbsp; uticaju doze nanomaterijala, početne koncentracije&nbsp; metala, pH vrednosti rastvora i kontaktnog vremena.&nbsp; Dobijeni rezultati prilikom ispitivanja uticaja&nbsp; doze nanomaterijala&nbsp; na efikasnosti uklanjanja odabranih metala iz vode primenom stabilisanih i &bdquo;zelenih&ldquo; nanomaterijala&nbsp; pokazali&nbsp; su&nbsp; da se povećanjem doze nanomaterijala&nbsp; povećava efikasnost uklanjanja.&nbsp; Prilikom primene stabilisanih nanomaterijala, koncentracije 14.00 gFe(0)/l,&nbsp; postignute&nbsp; su visoke efikasnosti uklanjanja, već pri dozama od&nbsp; 2 ml, dok je efikasnost uklanjanja primenom&nbsp; &bdquo;zelenih&ldquo; nanomaterijala koncentracije 1,395 gFe(0)/l bila niža. Prilikom ispitivanja uticaja pH vrednosti na uklanjanje metala iz vode primenom ispitivanih nanomaterijala, određeni &nbsp;su optimalni opsezi pH vrednosti pri kojima se postiže najveća adsorpcija metala&nbsp; na ispitivanim nanomaterijalima.&nbsp; Veza između metala&nbsp; i&nbsp; ispitivanih nanomaterijala obja&scaron;njena je modelovanjem Langmuir-ove i Freunlich-ove&nbsp; adsorpcione izoterme. Veće adsorpcione kapacitete prilikom adsorpcije svih ispitivanih metala pokazali su nanomaterijali produkovani &bdquo;zelenom&ldquo; sintezom u odnosu na stabilisane nanomaterijale, &scaron;to je povezano sa veličinom čestica, tj. manje nanočestice nanomaterijala produkovanih &bdquo;zelenom&rdquo; sintezom imaju veću&nbsp; specifičnu povr&scaron;inu i samim tim mogu&nbsp; ponuditi&nbsp; vi&scaron;e reaktivnih mesta, veću reaktivnost i bolju disperziju. Ispitivanje kinetike adsorcije&nbsp; Cr(VI), Cd(II), Cu(II), Ni(II), Pb(II) i As(III) na ispitivanim stabilisanim i &bdquo;zelenom&ldquo; sintezom produkovanim nanomaterijalima pokazalo je veoma brzu reakciju adsorpcije metala na ispitivanim&nbsp;nanomaterijalima i&nbsp; bolje slaganje eksperimentalno dobijenih podataka sa pseudo-drugim kinetičkim modelom.&nbsp; Rezultati dobijeni u ovom&nbsp; istraživanju omogućiće procenu&nbsp; primene nano Fe(0) za uklanjanje metala iz vode, posebno adsorpciju metala iz vode kao i odabir najefikasnijeg i najekonomičnijeg adsorbensa za uklanjanje različitih metala iz vode.</p> / <p>This work is concerned with exploring the possibility&nbsp; of&nbsp; application of&nbsp; stabilized nano Fe(0)&nbsp; and nano Fe (0) produced by &ldquo;green&rdquo; synthesis&nbsp; in the&nbsp; removal&nbsp; of Cr(VI), Cd(II), Cu(II), Ni(II), Pb(II)&nbsp; and&nbsp; As(III)&nbsp; from&nbsp; the&nbsp; water.&nbsp; Synthesis of nano Fe(0) for the stabilization is carried out according to conventional method of iron reduction with sodium borohydride in the presence of a material for stabilization: kaolinite, bentonite and carboxymethyl cellulose. Leaves of oak, mulberry and cherry trees used for&nbsp; &ldquo;green&rdquo;&nbsp; synthesis of nano Fe(0). Characterization of nanomaterials&nbsp; was performed by transmission and scanning electron microscopy.&nbsp; The&nbsp; characterization&nbsp; results&nbsp; have shown that during the synthesis and stabilization of nano Fe (0) process formed nanoparticles with size from 20 to 90 nm, while the nano Fe (0) particles synthesized by &quot;green&quot; method were within the&nbsp; size of&nbsp; 10-30 nm and characterized as spherical nanoparticles with&nbsp; various sizes without significant agglomeration.&nbsp; Application of nano Fe (0) on the&nbsp; removal&nbsp; efficiency of&nbsp; metals from water was studied under different conditions: the influence of&nbsp; nanomaterials&nbsp; dose, the initial metal concentrations, pH value of the solution&nbsp; and the contact time. The results obtained during the examination of the impact of nanomaterial&nbsp; dose&nbsp; on the&nbsp; removal&nbsp; efficiency&nbsp; of selected metals from water&nbsp; have shown that increasing&nbsp; of nanomaterial&nbsp; dose increases removal efficiency. High removal efficiency is achieved when used&nbsp; 2 ml of stabilized nanomaterials, concentration of 14.00 gFe(0)/L, while when &quot;green&quot; nanomaterials,&nbsp; concentration&nbsp; of&nbsp; 1,395&nbsp; gFe(0)/L,&nbsp; were&nbsp; used&nbsp; the removal efficiency&nbsp; was&nbsp; lower.&nbsp; The optimal ranges of pH values&nbsp; at which&nbsp; the tested&nbsp; nanomaterials&nbsp; reach the maximum adsorption of metals&nbsp; were obtained, during the examination of&nbsp; the influence of pH value on removal of metals from water by using the tested nanomaterials&nbsp; The&nbsp; relation&nbsp; between&nbsp; the metals&nbsp; and tested&nbsp;&nbsp; nanomaterials is explained by modeling&nbsp; of&nbsp; Langmuir&#39;s and Freunlich&#39;s adsorption isotherm.&nbsp; Nanomaterials&nbsp; produced&nbsp; by&nbsp; &quot;green&quot; synthesis&nbsp; showed higher&nbsp; adsorption capacity&nbsp; than&nbsp; stabilized&nbsp; nanomaterials, which is related&nbsp; with particle size, i.e. the&nbsp; nanoparticles&nbsp; produced by&nbsp; &quot;green&quot; synthesis&nbsp; have&nbsp; less particles, higher specific surface area and therefore can offer more reactive sites, greater reactivity and better dispersion. Kinetics&nbsp; tests&nbsp; showed a very fast adsorption of metal&nbsp; on&nbsp; the tested nanomaterials and better agreement with the experimental data to&nbsp; second&nbsp; pseudo-kinetic model.&nbsp; The results obtained in this study will enable the assessment of the application of nano&nbsp; Fe (0) for the removal of metals from water, especially for the adsorption of metals from water as well as the selection of the most&nbsp; efficient and most economical of the adsorbent for the removal of various metals from water.</p>

My dissertation focuses on the existence of metrics of non-positive curvature for the simplicial complexes constructed recently by Tom Brady and Daan Krammer for the braid groups and other Artin groups of finite type. In particular, for each Artin group of finite type, there is a recently constructed finite simplicial Eilenberg-Mac Lane space known as its Brady-Krammer complex. The Brady-Krammer complexes are highly symmetric objects. Prior work on the relationship between the Brady-Krammer complexes and the theory of CAT(0)spaces has produced some positive results in low-dimensions. More specifically, the Brady-Krammer complexes of dimension at most 3 have been shown to support piecewise Euclidean metrics of non-positive curvature. Similarly, the 4dimensional Brady-Krammer complexes of type A4 and type B4 also support such metrics. In every instance, the metrics assigned respect all of the symmetries alluded to above. The main results of my dissertation show that this pattern does not extend to the Brady-Krammer complexes of type F4 and D4. These are the first negative results known about the curvature of these Brady-Krammer complexes. The proofs of my main theorems involve a combination of combinatorial results and computer calculations. These negative results are particularly striking since Ruth Charney, John Meier and Kim Whittlesey have shown that a particular complex closely related to each Brady-Krammer complex admits an asymmetric metric satisfying a weak version of non-positive curvature. Thus, one corollary of my results is that the weak asymmetric version of a CAT(0) metric (initially defined by Mladen Bestvina) is strictly weaker than the traditional version.

My dissertation focuses on the existence of metrics of non-positive curvature for the simplicial complexes constructed recently by Tom Brady and Daan Krammer for the braid groups and other Artin groups of &#64257;nite type. In particular, for each Artin group of &#64257;nite type, there is a recently constructed &#64257;nite simplicial Eilenberg-Mac Lane space known as its Brady-Krammer complex. The Brady-Krammer complexes are highly symmetric objects. Prior work on the relationship between the Brady-Krammer complexes and the theory of CAT(0)spaces has produced some positive results in low-dimensions. More speci&#64257;cally, the Brady-Krammer complexes of dimension at most 3 have been shown to support piecewise Euclidean metrics of non-positive curvature. Similarly, the 4dimensional Brady-Krammer complexes of type A4 and type B4 also support such metrics. In every instance, the metrics assigned respect all of the symmetries alluded to above. The main results of my dissertation show that this pattern does not extend to the Brady-Krammer complexes of type F4 and D4. These are the &#64257;rst negative results known about the curvature of these Brady-Krammer complexes. The proofs of my main theorems involve a combination of combinatorial results and computer calculations. These negative results are particularly striking since Ruth Charney, John Meier and Kim Whittlesey have shown that a particular complex closely related to each Brady-Krammer complex admits an asymmetric metric satisfying a weak version of non-positive curvature. Thus, one corollary of my results is that the weak asymmetric version of a CAT(0) metric (initially de&#64257;ned by Mladen Bestvina) is strictly weaker than the traditional version.

A group W is said to have property FA_n if every action of W by isometries on an n-dimensional CAT(0) cell complex has a global fixed point. We construct a complex on which a Coxeter group W acts by cellular isometries without global fixed points, and show that under certain combinatorial conditions, complexes constructed in this way are CAT(0). We then construct several infinite classes of Coxeter groups which have property FA_2 but not property FA_3. / text

The purpose of this thesis is to explore some of the characteristics of 0-simple semigroups and completely 0-simple semigroups.

Abstact Introduktion: Beslut om 0-HLR kan tas av ansvarig läkare gällande patienter som inte bedöms ha förutsättningar att återfå spontan cirkulation och andningsfunktion vid ett hjärtstopp. Dessa beslut har visat sig utgöra grund för oenighet och osäkerhet hos vårdpersonal, anhöriga och patienter på sjukhus. Dock saknas forskning gällande distriktssköterskors och sjuksköterskors upplevelser av 0-HLR i hemsjukvård.. Syfte: Syftet var att undersöka distriktssköterskors och sjuksköterskors upplevelser av 0-HLR i hemsjukvård samt att identifiera förbättringsåtgärder. Metod: Kvalitativ intervjudesign med beskrivande karaktär utgjorde metoden där elva informanter från ett län i Mellansverige ingick. Data analyserades genom kvalitativ innehållsanalys. Resultat: Av resultatet framkom att det saknas tydliga rutiner för hur 0-HLR ska diskuteras och beslutas om i hemsjukvård. Personliga egenskaper hos vårdpersonal, patient och anhöriga styrde huruvida 0-HLR diskuterades eller ej. Man arbetade med 0-HLR i hemsjukvård fast på ett outtalat sätt och patienter visste inte alltid vad begreppet innebar. Behov att utveckla information och rutiner angående 0-HLR förelåg eftersom det rådde osäkerhet när akuta situationer uppstod.  Konklusion: Det framkom att 0-HLR är ett ämne som behöver lyftas för att undvika osäkerhet och otrygghet hos patienter, anhöriga och vårdpersonal gällande multisjuka patienter. Information, kunskapsuppdatering och rutiner behöver ses över och utformas för att bättre kunna följa med i utvecklingen av den personcentrerade vården.

Most studies of plant hybridisation are concerned with documenting its occurrence in different plant groups. Many flowering plants are polyploids and seeds developed from crosses between individuals of different ploidies usually show abnormal features and often abort. The success or failure of interploidy crosses is very important to understanding the evolution of plants as well as to agriculture, but much remains to be learned about the nature of hybridisation barriers. Several mechanisms have been proposed to explain postzygotic barriers, including negative interactions between diverged sequences, global genome rearrangements, and widespread epigenetic reprogramming. Some recent advances in our understanding of the process of hybridisation are derived from different experimental studies on a series of A. thaliana ecotypes. Crosses between diploid (2x) and tetraploid (4x) individuals of the same ecotype can result in F1 lethality, and this dosage-sensitive incompatibility plays a major role in polyploidy speciation research. We have performed interploidy crosses between different diploid maternal A. thaliana ecotypes and tetraploid paternal Col-0 ecotype and identified a genetic variation in F1 lethality. We also found that maternal parents of some ecotypes such as Tsu-1 suppressed the F1 lethality caused by paternal-excess interploidy cross of Col-0 ecotype. A preliminary mapping exercise produced advanced backcross populations that are suitable for mapping maternal modifiers and for the identification of modifier genes. Furthermore, we studied the killer effect caused by Col-0 and identified three additive QTL that affect the rate of postzygotic lethality in F1 during interploidy crosses. This information will facilitate the identification of paternal genes that cause F1 lethality and contribute to reproductive isolation. The moa-1 (mosaic aneuploidy 1) mutant of A. thaliana was obtained in a screen of chemically (EMS) mutagenised seeds of Landsberg erecta (Ler). moa-1 has various phenotypic differences to wild type; the preliminary karyotype analysis showed that the cells of individual moa-1 mutant plants have a variable number of chromosomes (usually between 11-18). In contrast, the cells of wild type Arabidopsis plants and conventional aneuploids have a fixed number of chromosomes in each somatic cell. This data showed that all moa-1 plants have an abnormal number of chromosomes and thus they were termed as mosaic aneuploids.

Neste trabalho descreve-se uma rota de preparação de nanopartículas de ródio (4 nm diâmetro médio) dispersas no líquido iônico tetrafluoroborato de 1-n-butil-3-metilimidazólio (BMI.BF4) e suportadas na rede de sílica pelos métodos sol-gel e grafting. Na preparação pelo método sol-gel (ácido ou básico) obteve-se materiais com diferentes quantidades de líquido iônico encapsulado e diferente morfologia da matriz de sílica. A quantidade de ródio suportado nos xerogéis resultantes foi (0,1% m/m). A condição ácida de preparação resultou em sílica com maior quantidade de líquido iônico encapsulado e com diâmetro de poro maior, podendo ser considerada como responsável pela atividade catalítica observada na hidrogenação de alcenos. A alta quantidade de líquido iônico incorporado pode ser importante para garantir a estabilidade das nanopartículas. O material catalítico preparado pelo método sol-gel pode ser recuperado por decantação e reutilizado por 10 vezes sem perda da atividade catalítica. As micrografias obtidas por microscopia eletrônica de transmissão do catalisador isolado depois de dez recargas mostraram que o material recuperado não apresentou sinais aparentes de aglomeração. A combinação (líquido iônico encapsulado/nanopartículas de ródio/sílica) exibe um excelente efeito sinérgico que aumenta a atividade catalítica e a robustez das nanopartículas de ródio para hidrogenação. Todos os sistemas suportados preparados foram mais ativos do que nanopartículas isoladas. / This work describes a route of preparation of rhodium nanoparticles (4 nm mean diameter) dispersed in an ionic liquid (1-n-butyl-3-methylimidazolium tetrafluoroborate) and supported within a silica network, prepared by the sol-gel method and grafting method. The sol-gel preparation method (acid or basic) gives materials with different contents in encapsulated ionic liquid and different silica morphology. The rhodium content in the resulting xerogels was (0.1 wt%). However, acidic conditions afforded higher contents of encapsulated ionic liquid and xerogels with larger pore diameters, which could be considered as responsible for the higher catalyst activity in hydrogenation of the alkenes. The catalytic material prepared by the sol gel method can be recovered by simple decantation and re-used at least ten times without any significant loss in catalytic activity. Transmission electron microscopy (TEM) of the catalyst isolated after ten recharges showed that the recovered material did not present apparent signs of agglomeration. The combination (ionic liquid/rhodium nanoparticles/silica) exhibits an excellent synergistic effect that enhances the activity and robustness of the rhodium hydrogenation catalysts. All the supported systems were more active than isolated rhodium nanoparticles for the hydrogenation of alkenes.