I prezzi dei generi alimentari sono cresciuti in modo considerevole in Etiopia a partire dal 2004. Questa tesi esamina a fondo gli effetti distributivi degli alti prezzi dei generi alimentari nelle zone rurali dell’Etiopia. Utilizzando il Rapporto di Beneficio Netto non parametrico ed il Sistema Quadratico di Domanda Quasi Ideale nonché stimando la Variazione Compensata, dimostra come gli alti prezzi dei generi alimentari possano avere effetti positivi sul benessere sociale delle famiglie rurali a livello aggregato. Tuttavia, i guadagni non sono distribuiti uniformemente tra le famiglie; una significativa percentuale di esse sono compratrici nette di cereali e potrebbero essere sfavorite da un aumento dei prezzi dei cereali qualora non beneficiassero di un aumento del reddito associato ad attività diverse dall’agricoltura. Teoreticamente, le famiglie rurali dovrebbero beneficiare di un aumento del prezzo dei generi alimentari poiché sono sia produttori sia consumatori dei prodotti. Un aumento della produttività agricola, attraverso l’intensificazione e la diversificazione delle produzioni, è un’importante strumento di politica economica che può limitare gli effetti negativi, di breve e di lungo periodo, sugli acquirenti netti rurali di generi alimentari derivanti da un aumento del loro prezzo. La tesi esamina anche la resilienza alla mancanza di cibo, la stagionalità nel consumo del cibo e la partecipazione nel mercato così come il ruolo dei trasferimenti monetari e delle preferenze dei beneficiari degli stessi. / Food prices in Ethiopia considerably rose since 2004. This thesis thoroughly examines the distributional impacts of high food prices in rural Ethiopia. Using the non-parametric Net Benefit Ratio analysis as well as Quadratic Almost Ideal Demand System and estimating Compensated Variation, it shows high food prices have positive impact on the welfare of rural households at aggregate levels. The gains, however, are not evenly distributed among households; large proportion of them are net cereal buyers (major staples) and could be adversely affected by rising cereal prices unless compensated by increase in income from off-farm activities. Theoretically, rural households should benefit from rising food prices as they are both consumers and producers of the products. Promoting agricultural productivity, through intensification and diversification, is an important policy tool to overcome short and long-run negative impacts of high food prices on rural net buyers. It also examines resilience to food insecurity, food consumption seasonality and market participation as well as cash transfers and beneficiaries preferences.

Bacterioplankton is characterized by high diversity, short generation times and rapid turnover. Despite their small size, these numerous microorganisms are a fundamental piece of aquatic ecosystems by channeling carbon to higher trophic levels through dissolved organic matter utilization. Yet, several gaps remain in our knowledge and understanding of bacterioplankton populations regarding detailed temporal dynamics, and mechanisms determining biogeographical patterns and potential responses to climate change. The aim of this thesis was to examine responses in bacterioplankton community composition and function when challenged by natural and anthropogenically-induced change in environmental conditions. High temporal resolution analysis of bacterioplankton population dynamics in the Baltic Sea indicated detailed seasonal responses. It also showed a similar but wide spectrum of niche differentiation patterns within several major bacterial groups. Analysis of geographic distributions of marine bacterial populations revealed bimodal occupancy-frequency patterns in bacterial communities, indicating that the presence of many locally rare taxa along with a few locally abundant taxa were explained by stochastic variation in colonization and extinction rates. Experimental manipulations with natural marine bacterioplankton assemblages revealed both specialist and generalist strategies in utilizing specific dissolved organic carbon compounds. When subjected to experimentally increased sea surface temperatures, lowered pH and additions of terrigenous carbon, some populations decreased in relative abundance while others were stable; concomitantly, many populations increased in relative abundance. Shifts in bacterial community composition were shown to correlate with changes in community functioning, but detection of such correlations depended largely on the detail of phylogenetic analysis and successional stage of the communities. The results in this thesis suggest that both natural and anthropogenically-induced changes in environmental conditions promote simultaneous adjustment and replacement of bacterial populations tightly linked with metabolic plasticity. These trade-offs play a significant role for understanding the relationship between bacterioplankton population dynamics and potential shifts in carbon cycling properties. We also show the importance of regional effects in shaping bacterial community composition, crucial for interpreting bacterioplankton distribution patterns. In conclusion, this thesis emphasizes the critical importance of connecting analysis of bacterioplankton population dynamics with examination of ecological mechanisms to improve our understanding of factors that regulate the distribution and activity of distinct bacterioplankton populations. / Hälften av all fotosyntes på vår planet utförs av växtplankton. De producerar organiskt material som utgör grunden för näringskedjan i havet. Ungefär hälften av det organiska material som produceras av växtplankton utnyttjas inte direkt, utan omsätts istället av bakterieplankton som lever och växer fritt i vattenmassan eller på olika partiklar. Bakterieplankton spelar därmed en nyckelroll i ekosystemet genom sin konsumtion av organiskt kol som för energi högre upp i näringskedjan. Trots deras nyckelroll i akvatiska miljöer vet vi fortfarande mycket lite om bakteriernas detaljerade säsongsmönster, mekanismer bakom rumsliga mönster och hur olika populationer kan komma att svara på klimatförändringar. Målet med denna avhandling var att undersöka hur specifika populationers dynamik och ekosystemfunktion påverkas av naturliga eller klimatorsakade förändringar i havsmiljön. Våra resultat av högupplöst säsongsbunden dynamik i Östersjöns bakteriesamhälle avslöjar en liknande bred uppdelning av ekologiska strategier inom varje större grupp av bakterier, både i relativ abundans och temporal fördelning. Utbredning i rum och tid av många lokalt ovanliga populationer jämfört med få lokalt vanliga populationer förklarades genom stokastisk variation i kolonisations- och utdöendehastigheter. Vidare tyder experimentella studier med tillsatser av olika kolkällor på att marina bakterier har olika ekologiska strategier, där populationer är specialister eller generalister i utnyttjandet av enskilda kolkällor. Med hjälp av experiment med naturliga bakteriesamhällen bekräftade vi tydliga temperatureffekter på bakteriesamhällets sammansättning, och en mindre effekt av lägre pH - som dock tillsammans med förhöjd temperatur bidrog till en tydlig synergistisk effekt på artsammansättningen. Ökad temperatur tillsammans med tillsats av terrestert kol gav också en stor effekt på bakteriesamhällets struktur och ekosystemfunktion och pekar på en potentiellt viktig påverkan av ökad framtida nederbörd och avrinning från vattendrag till havet. Samtliga tre experiment med fokus på klimatpåverkan bekräftade förekomsten av populationer som försvann eller minskade i relativ abundans vid klimatpåverkan (känslighet), medan andra var stabila (resistens). Samtidigt svarade många populationer positivt på klimatorsakade förändringar i havsmiljön och ökade i relativ abundans (respons) samtidigt som bakteriernas ekosystemfunktion påverkades positivt. Sammanfattningsvis visar denna avhandling att vissa nya bakteriepopulationer kan etablera sig och ersätta andra samtidigt som vissa befintliga populationer anpassar sin livsstrategi och ekologi till förändringar i havsmiljön. Vi visar också vikten av regionala effekter, d.v.s. kolonisation och utdöende, för bakteriesamhällets struktur, viktigt för tolkningen av biogeografiska mönster och den genomiska potentialen hos specifika populationer. Denna avhandling poängterar därmed betydelsen av att koppla studier av ekologiska mekanismer till både rumsliga och temporala spridningsmönster hos bakterier och till populationers kapacitet att svara på och anpassa sig till förändringar i havsmiljön.

Aquatic ecosystems are an essential source for life and, in many regions, are exploited to a degree which deteriorates their ecological status. Today, more than 50 % of the European lakes suffer from an ecological status which is unsatisfactory. Many of these lakes require abatement actions to improve their status, and mathematical models have a great potential to predict and evaluate different abatement actions and their outcome. Several statistical methods and models exist which can be used for these purposes; however, many of the models are not constructed using a sufficient amount or quality of data, are too complex to be used by most managers, or are too site specific. Therefore, the main aim of this thesis was to present different statistical methods and models which are easy to use by managers, are general, and provide insights for the development of similar methods and models. To reach the main aim of the thesis several different statistical and modelling procedures were investigated and applied, such as genetic programming (GP), multiple regression, Markov Chains, and finally, well-used criteria for the r2 and p-value for the development of a method to determine temporal-trends. The statistical methods and models were mainly based on the variables chlorophyll-a (chl-a) and total phosphorus (TP) concentrations, but some methods and models can be directly transferred to other variables. The main findings in this thesis were that multiple regressions overcome the performance of GP to predict summer chl-a concentrations and that multiple regressions can be used to generally describe the chl-a seasonality with TP summer concentrations and the latitude as independent variables. Also, it is possible to calculate probabilities, using Markov Chains, of exceeding certain chl-a concentrations in future months. Results showed that deep water concentrations were in general closely related to the surface water concentrations along with morphometric parameters; these independent variables can therefore be used in mass-balance models to estimate the mass in deep waters. A new statistical method was derived and applied to confirm whether variables have changed over time or not for cases where other traditional methods have failed. Finally, it is concluded that the statistical methods and models developed in this thesis will increase the understanding for predictions within and across aquatic systems.

The purpose of this paper is to examine the correlation between hotels, their brands and the frontline staff within the industry. A competitive, international environment characterizes today´s hotel industry where brands are one of the strongest sources for a successful position amongst competitors. In the brand delivery, the front line staff is of utmost importance since they in many ways incorporate the brand values and the projected identity of the hotel. Hotels can use a variety of ways to communicate the brands identity to the front line staff in order to create the desired brand behavior, some more effective than others. At the same time the Swedish hotel industry, as many other, is characterized by a high percentage of staff turnovers. This is caused by the fact that part time or seasonal front line employees staff much of the hotels. This creates a possible tension since those delivering the service often are staff with limited brand awareness while at the same time the hotels are dependent of a constant brand delivery to create a sustainable brand image. The study has been made through a qualitative approach and as a case study of a representative part of the Swedish hotel industry. We have conducted 7 interviews with various people, all working in management at different hotels. Research findings show that while there is an understanding of the front line staffs part in brand communication, the implementation phase is troublesome. In order for the staff to communicate the hotel brand true to the hotels proposed brand identity there is a need for a symbiotic relationship between the hotels management and the front line staff. A model for this relationship is therefore proposed by us.

This master's essay is about seasonality in Bristols slave trade until the American Revolution 1776. The essay uses the Voyages database as the primary material. The essay's method is to study monthly distribution at different points of the slave trade – the departure from Bristol and the arrival at the American destination. The seasonality of slave purchases in Africa is primarly studied through the monthly distribution of departures from Bristol for a specific region in Africa. This methodological choice is based on the lack of coverage of African arrival dates. The theoretical groundwork in the essay is foremost based on Henri Lefebvre's concept of rhytm analysis. The results of the essay show that there usually was some seasonality in the different parts of Bristol's slave trade. The essay tries to relate this seasonality with possible explanations, like the need of provisions, trade goods, harvest cycles in Africa and America, though the essay doesn't have any pretensions of proving actual causal relations, just that the seasonality of the slave trade coincided with other seasonal cycles.

This thesis adopts an empirical approach to examine various market microstructure issues, using data from the National Stock Exchange of India (NSE). Whilst the respective empirical analyses may be considered as self-contained investigations, they are primarily linked through the common objective of understanding the mechanics of the pricing process as it occurs on actual markets, using the NSE as exemplar. The first major focus of the dissertation is non-synchronous trading: empirical evidence of nonsynchronicity is obtained by testing for predictability as between indices of different levels of liquidity. A simple test of the analysis of trading-break returns is proposed to infer whether predictability may be mainly attributable to non-synchronous trading or whether it constitutes a delayed adjustment of traders' expectations. The second question tackled in the thesis is whether volatility on the NSE may be considered as justified or excessive. Rathert han adopting the established methodology of comparing stock price changes to information about expected dividends, the research question is split up into two subsidiary ones. The first question is whether volatility is related to information flows, whilst the second related questionc oncernst he relationship betweenv olatility and returns. Three sources of excessive volatility are pin-pointed. Monday effects are found in index data but not in the underlying stocks-indicating index fluctuations which are not information-related. A second indicator of excessive price movements is the pronounced volatility which coincides with the fiscal year end of quoted companies but which is not accompanied by a similar increase in long-term returns. A third indication of unjustified price fluctuations is that volatility seems unrelated to returns when considering a long-term time series. The third topic of the thesis relates to the efficacy of opening and closing call auctions. This issue may be considered as the crux of the dissertation and it is tackled by analysing the effects of the suspension of a call auction system on NSE. Changes in volatility, efficiency and liquidity following the suspension are analysed, and an event study is presented. The relationship between call auctions and long-term volatility is also investigated. The findings suggest that the expected benefits of call auctions may not always materialise, possibly due to an inappropriately structured auction, or because a liquidity threshold for stocks must be surpassed for the expected benefits to accrue.

生育事件究竟是一種生物事件(biological events)或是社會事件(social events)，一直以來，引發學者不同面向之探討，然至今尚無定論。對於生育行為是否存在季節性之變化，過去的研究結果呈現不同之見解。本研究企圖釐清生育事件是否存在特定季節或其他之變化模式，特別利用台灣地區歷年(1906~2003)生育資料，經由統計運算與圖形之呈現，證實台灣地區生育事件之變遷模式，確實存在季節模式之變化。整體而言，生育事件的季節週期模式，呈現U型，以四月到七月為出生淡季、十月到隔年一月為出生高峰。但此一模式在「結婚事件的季節週期模式」維持穩定不變的前提下，一九七０年代開始慢慢逐漸式微，甚至到了九０年代二十一世紀初，生育事件的月份波動情形已轉為年終高峰之左傾模式。 綜合言之，促使台灣地區生育事件典型季節模式的解釋機制主要可以歸納為「農業週期」與「節慶」兩點。另外，對於導致整個二十世紀台灣地區生育事件季節性模式變遷的原因討論中，在「結婚事件的季節模式」穩定持續存在前提之下，意味著「結婚」與「生育」兩者間的傳統直接關係受到了其他變項的介入，亦或者在「結婚事件」與「生育事件」之上，存在著前置變項(antecedent variables)的影響。 隨著七０年代之後，台灣正式進入工業化開發中國家之列，經濟產業結構的轉變，亦可能是導致七０年代開始，台灣地區生育事件的季節週期逐漸脫離傳統U型模式的因素之一。 最後，對於改變近期台灣地區生育事件季節模式最重要也最關鍵的原因乃是，自一九六０年代開始迄今，在政府成功地推行多次家庭計畫下，子宮內避孕器裝置、口服避孕藥、保險套與男女性結紮等有效的人工避孕方法之誕生與普及化，徹底改變了國人傳統的生育態度與行為。同時，對於生育知識的瞭解，以及對於生育控制能力的增加，亦大幅度地降低了外在自然環境對於人們生育行為的干涉程度。因此，「家庭計畫」對於七０年代之後台灣地區生育事件季節模式的淡化與式微，占有擧足輕重之地位。

Made available in DSpace on 2014-12-17T14:52:36Z (GMT). No. of bitstreams: 1 AndressaAM.pdf: 2376539 bytes, checksum: 6e9e7fed58e84a30eb37203219b70dbd (MD5) Previous issue date: 2007-12-19 / The aim of this work is to analyse the tourism events and the performance of this segment from market as strategy in the combat of Natal's hotel seasonality, in the executives/managers's vision from this sector. Two searches were realized to turn available this study: Inicialy a bibliographic search involving the concepts associated with the tematic in question so that it arranges the embasament theoric-scientific and a survey from facts through the country search, where it was applicable in the establishments of work's population with the auxiliary from a formulary answered by a personal interview. The analyses techniques through facts were: estatistic descritive and Kolmogorov-smirnov test.Among the results found, it was verified that the main reasons alleged by the hotels to ingress in the segment from the events were the alinement from the competitive company, the diversification in the options in the sense of occupy the establishments during the period of low season and answer to the demand of market. Investigated the profile from the events occured in the Natal hotels referring to the port, public origin , kinds of events and frequency from their realizations, as well as , the capacity from these establishments to attend this segment.It was noticed that in spite of the hotels agree that the events are important estrategies to combat the seasonality, the establishments still suffer with the flutuation, what can be justified from the moment that it's considered that the events also behave from seasonal manner, having more concentration in certain periods from the year. It was evaluated that the main advantage noticed by the realization from the hotels's events is the utilization from alimentation and drinking services, surpassing the advantage from elevation of taxes occupation from the apartments / O objetivo deste trabalho foi analisar o turismo de eventos e a atua??o deste segmento de mercado como estrat?gia no combate ? sazonalidade na hotelaria de Natal, na vis?o de executivos/gerentes do setor. Para viabiliza??o deste estudo duas pesquisas foram realizadas: inicialmente uma pesquisa bibliogr?fica envolvendo os conceitos associados ? tem?tica em quest?o de forma a proporcionar o embasamento te?rico-cient?fico e um levantamento de dados atrav?s de pesquisa de campo, a qual foi aplicada nos estabelecimentos da popula??o do trabalho com o aux?lio de um formul?rio respondido mediante entrevista pessoal. As t?cnicas de an?lise dos dados foram: estat?stica descritiva e teste Kolmogorov-Smirnov. Dentre os resultados encontrados, constatou-se que os principais motivos alegados pelos hot?is para ingressar no segmento de eventos foram o alinhamento ?s empresas concorrentes, a diversifica??o nas op??es no sentido de ocupar os estabelecimentos durante o per?odo de baixa temporada e resposta ? demanda de mercado. Investigou-se o perfil dos eventos ocorridos nos hot?is de Natal no que se refere ao porte, origem do p?blico, tipos de eventos e freq??ncia de realiza??o dos mesmos, bem como a capacidade destes estabelecimentos para atender a este segmento. Apontou-se que apesar de os hot?is concordarem que os eventos s?o estrat?gias importantes no combate ? sazonalidade, os estabelecimentos ainda sofrem com os efeitos da flutua??o da demanda, o que pode ser justificado a partir do momento em que se considera que os eventos tamb?m se comportam de maneira sazonal, havendo maior concentra??o em certos per?odos do ano. Avaliou-se que a principal vantagem percebida pela realiza??o dos eventos nos hot?is ? a utiliza??o dos servi?os de alimentos e bebidas, superando a vantagem da eleva??o das taxas de ocupa??o dos apartamentos

La saisonnalité de la reproduction consiste en l’alternance entre des périodes d’activité et de repos sexuel. Ce phénomène s’observe chez les caprins de la région subtropicale du Mexique et rend impossible la reproduction à contre saison. La réintroduction d’un mâle dans un groupe de femelles peut rompre l’anoestrus saisonnier et rapidement stimuler leur activité ovarienne. Cependant, l’utilisation de boucs induits à un comportement sexuel intense pendant la période de repos sexuel au moyen d’un traitement lumineux –mâles photo-stimulés- est nécessaire afin d’assurer la qualité de la stimulation fournie par ceux-ci. Le temps de contact entre les sexes est un autre facteur pouvant moduler la réponse des femelles et il a longtemps été suggéré que ce contact devait être maintenu de manière continue (24h/24) pendant plusieurs jours afin que la majorité des femelles ovulent. L’objectif de cette thèse a été de déterminer si une réduction du temps de contact journalier entre les sexes diminue les réponses ovulatoire et reproductrice de chèvres en anoestrus saisonnier exposées aux mâles. / Seasonality of reproduction consists of alternations between periods of sexual activity and sexual rest (anoestrus). This seasonality is observed in goats from subtropical Mexico and makes impossible out-of-season reproduction. The reintroduction of a male in a group of females can break the seasonal anoestrus and quickly stimulate ovarian activity. However, the use of bucks induced to a high sexual activity during the sexual rest by a treatment of long days –photo-stimulated males- is necessary to ensure the quality of stimulation provided by them. The duration of contact between sexes is another factor that modulates the response of females and it has long been suggested that it should be maintained continuously (24h/24) for several days so that the majority of females ovulate. The purpose of this thesis was to determine whether a reduction of daily contact between sexes decrease ovulatory and reproductive responses of goats exposed to males during the seasonal anoestrus. The results indicate that duration of contact between sexes can be drastically reduced from 16 to 1 h per day without reducing the ovulatory and reproductive responses of females.

O gênero Erythroxylum P. Browne pertence a família Erythroxylaceae Kunth e é principalmente conhecido devido as espécies E. coca e E. novogranatense, as “plantas da coca”. O gênero é a única fonte natural da cocaína e de outros alcaloides com núcleo ecgonina, principais responsáveis pelos efeitos tóxicos e biológicos originados pelo consumo de suas espécies. A presença da cocaína é amplamente aceita para as plantas de coca, porém a sua biossíntese por outras espécies apresenta divergência, o que pode estar relacionada ao período de coleta. Além destas particularidades fitoquímicas, as espécies do gênero também apresentam importantes atividades como antioxidante e antimicrobiana, além de toxicidade a humanos e a ovinos. O Brasil é o centro da diversidade e do endemismo do gênero e no sul do país, nos estados do Rio Grande do Sul e de Santa Catarina, as carcaterísticas fitoquímicas e potencialidades tóxicas e farmacológicas das espécies apresentam um campo aberto para estudos. Desta forma, foram avaliadas características fitoquímicas e potencialidades tóxicas e farmacológicas de espécies nativas dos estados do Rio Grande do Sul e de Santa Catarina, coletadas em dois períodos climáticos distintos, verão e inverno, além de revisão bibliográfica sobre as espécies produtoras de cocaína e as implicações segundo a legislação brasileira vigente. Foram utilizadas metodologia de planária, disco-difusão em ágar, microdiluição em caldo, medida da extinção da absorção do cátion 2,2-difenil-1-picrilhidrazil e procedimentos preconizados pelas Nações Unidas para a investigação fitoquímica de espécies produtoras de cocaína. Foi verificado que 24 espécies apresentam o aparato enzimático para a produção da cocaína. Embora E. novogranatense origina rendimentos apropriados ao tráfico, segundo a legislação Brasileira vigente, apenas E. coca encontra-se proscrita, o que torna necessário a inclusão de E. novogranatense na lista de plantas proscritas. Para o estudo toxicológico desenvolvido com E. deciduum sobre modelo de planária, foi necessário adaptar a metodologia existente. O extrato da espécie ocasionou aumento significativo da velocidade de locomoção (p= 0.016) e comportamentos estereotipados padronizados de posição tipo C e hipercinesia tipo parafuso, eventos característicos da neurotransmissão dopaminérgica em planárias. Os resultados, além de ampliar as possibilidades do uso destes vermes na busca por extratos ativos, demonstram que E. deciduum biossintetiza metabólitos ativos sobre este neurotransmissor, os quais podem estar relacionados com os efeitos ocasionados pelo consumo da espécie vegetal. A influência do período de coleta sobre as potencialidades farmacológicas e as características fitoquímicas foi investigada e os resultados demonstram esta infuência. Diferentes extratos de E. argentinum e E. deciduum, coletadas durante o verão, apresentaram atividade antimicrobiana superiores a verificada para os extratos obtidos de coletas realizadas no inverno. O extrato etanólico de E. argentinum, coleta verão, pode ser considerado um verdadeiro antimicrobiano, MIC= 0,78mg/ mL, e desta forma torna-se uma fonte promissora para a descoberta de novas moléculas antimicrobianas. Os extratos das espécies E. argentinum e E. deciduum demonstram pertinentes resultados sobre a atividade antioxidante. A influência do período de coleta, verão/ inverno, sobre a atividade foi identificada. A influência do período de coleta sobre as atividades tóxico-farmacológicas é corroborada pelo perfil alcaloídico obtido de noves espécies do gênero, coletadas durante o verão e o inverno, nos estados do Rio Grande do Sul e de Santa Catarina. O perfil alcaloídico das espécies E. amplifolium, E. argentinum, E. cuneifolium, E. cuspidifolium, E. deciduum, E. microphyllum, E. myrsinites, E. pelleterianum e E. vacciniifolium demonstra a presença dos alcaloides: éster de metecgonidina, éster de metilecgonina, cuscohigrina e tropacocaína e dos intermediários da biossíntese: higrina, tropinona e tropanol. A identificação dos metabólitos éster de metilecgonina e éster de metilecgonidina também demonstra que as espécies do gênero Erythroxylum presentes no Sul do Brasil apresentam potencialidade econômicas, pois podem ser empregadas na produção de padrões toxicológicos. Os objetivos propostos foram cumpridos e permitem concluir que espécies do gênero Erythroxylum dos estados do Rio Grande do Sul e de Santa Catarina, Sul do Brasil, demonstram importância tóxica, farmacológica e química, sendo parte destas influenciada pelo período de coleta, verão/ inverno. / “Chemical and Biological Study of Erythroxylum P. Browne Species Collected in Southern Brazil”. Erythroxylum P. Browne genus belongs to the Erythroxylaceae Kunth family and is mainly known due to E. coca and E. novogranatense species, the "coca plants". The genus is the only natural source of cocaine and other alkaloids with ecgonine nucleus, mainly responsible for the toxic and biological effects caused by the consumption of their species. The presence of cocaine is widely accepted for coca plants, but its biosynthesis by other species shows divergence, which may be related to the collect period. Besides these phytochemical peculiarities, the species of the genus also present important activities such as antioxidant and antimicrobial, besides toxicity to humans and sheep. Brazil is the center of diversity and endemism of the genus and in the south of the country, in the states of Rio Grande do Sul and Santa Catarina, the phytochemical characteristics, toxic and pharmacological potentials of the species present an open field for studies. Thus, phytochemical characteristics, toxic and pharmacological potentials of native species of the states of Rio Grande do Sul and Santa Catarina were assessed, collected in two distinct climatic periods, summer and winter, as well as a bibliographical review on cocaine producing species and implications under current Brazilian law. Some methodologies were used such as planaria, disc-diffusion in agar, microdilution in broth, extinction measurement of the absorption of cation 2,2-diphenyl-1-picrylhydrazyl and procedures recommended by the United Nations for the phytochemical investigation of cocaine producing species. It was verified that twenty-four species present the enzymatic apparatus for the production of cocaine. Although E. novogranatense originate income appropriate to traffic according to current Brazilian legislation, only E. coca is outlawed, which makes it necessary to include E. novogranatense in the list of proscribed plants. For the toxicological study developed with E. deciduum on planaria model, it was necessary to adapt the existing methodology. The extract of the species caused a significant increase in locomotion velocity (p= 0.016) and standardized stereotyped behaviors of type C position and screw- type hyperkinesia, characteristic events of dopaminergic neurotransmission in planarians. The results, besides expanding the possibilities of the use of these worms in search for active extracts, demonstrate that E. deciduum biosynthesizes active metabolites on this neurotransmitter, which may be related to the effects caused by the consumption of the plant species. The influence of the collect period on pharmacological potentials and phytochemical characteristics was investigated and the results demonstrate this influence. Different extracts of E. argentinum and E. deciduum collected during summer showed higher antimicrobial activity than the extracts obtained from winter collect. The ethanolic extract of E. argentinum, summer collect, may be considered a true antimicrobial, MIC= 0.78mg/ mL, on Staphylococcus aureus, and in this way it becomes a promising source for the discovery of new antimicrobial molecules. The extracts of E. argentinum and E. deciduum species demonstrate relevant results on antioxidant activity. The influence of the collecting period, summer/ winter, on the activity was verified. The influence of collect period on toxic- pharmacological activities is corroborated by the alkaloid profile obtained from nine species of the genus, collected during summer and winter in the states of Rio Grande do Sul and Santa Catarina. The alkaloid profile of E. amplifolium, E. argentinum, E. cuneifolium, E. cuspidifolium, E. deciduum, E. microphyllum, E. myrsinites, E. pelleterianum and E. vacciniifolium species shows the presence of alkaloids: ecgonidine methyl ester, ecgonine methyl ester, cuscohygrine and tropacocaine and the biosynthesis intermediates: hygrine, tropinone and tropanol. The identification of the ecgonine methyl ester and ecgonidine methyl ester also shows that Erythroxylum genus species present in southern Brazil have economic potential because they can be used in the production of toxicological standards. The aims were met and allow the conclusion that Erythroxylum genus of Rio Grande do Sul and Santa Catarina states, south of Brazil, show toxic, pharmacological and chemical importance, part of these being influenced by the collect period, summer/ winter.