File systems store data in files and organize these files in directories. Over decades, file systems have evolved to handle increasingly large files: they distribute files across a cluster of machines, they parallelize access to these files, they decouple data access from metadata access, and hence they provide scalable file access for high-performance applications. Sadly, most cluster-wide file systems lack any sophisticated support for large directories. In fact, most cluster file systems continue to use directories that were designed for humans, not for large-scale applications. The former use-case typically involves hundreds of files and infrequent concurrent mutations in each directory, while the latter use-case consists of tens of thousands of concurrent threads that simultaneously create large numbers of small files in a single directory at very high speeds. As a result, most cluster file systems exhibit very poor file create rate in a directory either due to limited scalability from using a single centralized directory server or due to reduced concurrency from using a system-wide synchronization mechanism. This dissertation proposes a directory architecture called GIGA+ that enables a directory in a cluster file system to store millions of files and sustain hundreds of thousands of concurrent file creations every second. GIGA+ makes two indexing technique to scale out a growing directory on many servers and an efficient layered design to scale up performance. GIGA+ uses a hash-based, incremental partitioning algorithm that enables highly concurrent directory indexing through asynchrony and eventual consistency of the internal indexing state (while providing strong consistency guarantees to the application data). This dissertation analyzes several trade-offs between data migration overhead, load balancing effectiveness, directory scan performance, and entropy of indexing state made by the GIGA+ design, and compares them with policies used in other systems. GIGA+ also demonstrates a modular implementation that separates directory distribution from directory representation. It layers a client-server middleware, which spreads work among many GIGA+ servers, on top of a backend storage system, which manages on-disk directory representation. This dissertation studies how system behavior is tightly dependent on both the indexing scheme and the on-disk implementations, and evaluates how the system performs for different backend configurations including local and shared-disk stores. The GIGA+ prototype delivers highly scalable directory performance (that exceeds the most demanding Petascale-era requirements), provides the traditional UNIX file system interface (that can run applications without any modifications) and offers a new functionality layered on existing cluster file systems (that lack support for distributed directories)contributions: a concurrent

Personal digital records are one of the most underrepresented areas of archival theory and practice. Documentary forms created by private persons have long been victim of a poverty of professional attention, and much of the literature on the appraisal and preservation of records has tended to focus on those generated by government and other organizational entities. And strategies developed for the archival management of digital records have similarly placed strong emphasis on business functions or corporate transactions as the primary unit of analysis. This scholastic deficit has severely impaired the ability of the archivist to comprehend and effectively meet the many challenges of archiving personal records in the digital age. This thesis demonstrates how investigations of the original context of creation and use of records in contemporary personal computing environments are integral to the development of comprehensive strategies for the capture and preservation of personal digital archives. It is within these digital domains that archivists come to see cultures of personal recordkeeping, private appraisal decisions based on unique designations of value, and the complexities of both online and offline personal digital preservation strategies. A keen understanding of how individuals create and preserve their digital records across time and space should be of the utmost importance to archivists for, if nothing else, these pre-custodial activities are the principal sites of archival provenance. Chapter one discusses past and present responses to both paper-based and electronic personal archives. The discussion begins with the definition of the personal record as essentially non-archival by early leading archival theorists and how these definitions, though first advanced in the early to mid-twentieth century, continue to find resonance in contemporary archival ideas and institutional mandates. This chapter then illustrates how ideas predicated on the management of electronic government records, and metadata standards developed for formalized electronic recordkeeping systems, are not easily transposed to personal domains. Chapter two takes a critical look at the often oversimplified personal digital archiving environment to expose the many nuances in the context of creation and use of records by individuals in the digital era. Chapter three explores a number of emerging approaches to the professional archiving of personal digital records and reveals how the proper management of these materials requires multiple hardware and software applications, concise acquisition strategies and preservation methodologies, and diligent front-end work to ensure personal digital records cross the threshold of archival repositories. The thesis concludes with a summary of the main arguments and collates the best ideas, approaches, and technologies reviewed throughout to propose a hypothetical strategy for archiving personal digital records in the present. This thesis argues that significantly more work with records creators earlier in the record creation process must be done when archiving personal digital records because more proactive measures are required to capture and preserve these materials than was previously the case with paper-based or analog documentary forms.

Personal digital records are one of the most underrepresented areas of archival theory and practice. Documentary forms created by private persons have long been victim of a poverty of professional attention, and much of the literature on the appraisal and preservation of records has tended to focus on those generated by government and other organizational entities. And strategies developed for the archival management of digital records have similarly placed strong emphasis on business functions or corporate transactions as the primary unit of analysis. This scholastic deficit has severely impaired the ability of the archivist to comprehend and effectively meet the many challenges of archiving personal records in the digital age. This thesis demonstrates how investigations of the original context of creation and use of records in contemporary personal computing environments are integral to the development of comprehensive strategies for the capture and preservation of personal digital archives. It is within these digital domains that archivists come to see cultures of personal recordkeeping, private appraisal decisions based on unique designations of value, and the complexities of both online and offline personal digital preservation strategies. A keen understanding of how individuals create and preserve their digital records across time and space should be of the utmost importance to archivists for, if nothing else, these pre-custodial activities are the principal sites of archival provenance. Chapter one discusses past and present responses to both paper-based and electronic personal archives. The discussion begins with the definition of the personal record as essentially non-archival by early leading archival theorists and how these definitions, though first advanced in the early to mid-twentieth century, continue to find resonance in contemporary archival ideas and institutional mandates. This chapter then illustrates how ideas predicated on the management of electronic government records, and metadata standards developed for formalized electronic recordkeeping systems, are not easily transposed to personal domains. Chapter two takes a critical look at the often oversimplified personal digital archiving environment to expose the many nuances in the context of creation and use of records by individuals in the digital era. Chapter three explores a number of emerging approaches to the professional archiving of personal digital records and reveals how the proper management of these materials requires multiple hardware and software applications, concise acquisition strategies and preservation methodologies, and diligent front-end work to ensure personal digital records cross the threshold of archival repositories. The thesis concludes with a summary of the main arguments and collates the best ideas, approaches, and technologies reviewed throughout to propose a hypothetical strategy for archiving personal digital records in the present. This thesis argues that significantly more work with records creators earlier in the record creation process must be done when archiving personal digital records because more proactive measures are required to capture and preserve these materials than was previously the case with paper-based or analog documentary forms.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-15T00:07:45Z No. of bitstreams: 1 ErikaPaulaSilvaFreitasDeOliveira_DISSERT.pdf: 1875508 bytes, checksum: 4bfd3ff4fc3e27d660f60ba378499f40 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-16T23:28:34Z (GMT) No. of bitstreams: 1 ErikaPaulaSilvaFreitasDeOliveira_DISSERT.pdf: 1875508 bytes, checksum: 4bfd3ff4fc3e27d660f60ba378499f40 (MD5) / Made available in DSpace on 2017-03-16T23:28:34Z (GMT). No. of bitstreams: 1 ErikaPaulaSilvaFreitasDeOliveira_DISSERT.pdf: 1875508 bytes, checksum: 4bfd3ff4fc3e27d660f60ba378499f40 (MD5) Previous issue date: 2016-12-01 / A s?ndrome metab?lica (SM) ? uma doen?a multifatorial, cujas altera??es fisiopatol?gicas podem comprometer o status de zinco. O objetivo deste estudo foi avaliar os biomarcadores do status de zinco e as associa??es com fatores de risco cardiometab?licos em indiv?duos com SM. Trata-se de um estudo tipo caso-controle, desenvolvido com 88 adultos e idosos com SM, caracterizados segundo os crit?rios do National Cholesterol Education Program - Adult Treatment Panel III (NCEP/ATP-III), e 37 indiv?duos sem SM ou outra condi??o cl?nica com influ?ncia nos par?metros de zinco. Foram realizadas avalia??es cl?nicas, antropom?tricas, perfil lip?dico, glic?mico e inflamat?rio. Verificou-se a ingest?o de zinco, concentra??es de zinco no plasma e eritr?cito, bem como a excre??o de zinco na urina, pelo m?todo de espectrofotometria de absor??o at?mica. Diferen?as entre os grupos foram avaliadas por modelos de regress?o. Correla??es foram identificadas pelo coeficiente de Pearson (r). A idade m?dia dos participantes foi de 50 (11) anos e 44 (11) anos para o grupo de pacientes com SM e controles, respectivamente. A m?dia da ingest?o cal?rica di?ria foi significativamente maior para os pacientes com SM (p = 0,003), e a ingest?o diet?tica de ambos os grupos caracterizou-se como hiperproteica, normoglic?dica e normolip?dica. O consumo m?dio de zinco foi significantemente menor no grupo SM comparado com o controle (6,57(1,64) mg/dia vs 9,37(2,41) mg/dia; p<0,001). N?o foram observadas diferen?as significativas nas concentra??es de zinco no plasma (88,81(18,28) ?g/dL vs 87,82(17,44) ?g/dL; p>0,05). Identificou-se concentra??es significantemente maiores de zinco no eritr?cito no grupo SM (47,47(8,29) ?g/gHb vs 41,43(7,37) ?g/gHb; p<0,001), independente dos ajustes por covari?veis. A excre??o de zinco na urina foi significantemente maior no grupo SM (554,80(291,00-787,60) ?g/24h vs 375,40(197,60-597,50) ?g/24h; p=0,008), e os ajustes por idade e sexo explicaram 21% das diferen?as (R2=0,21; p<0,001). No grupo SM foram constatadas associa??es significativas entre zinc?ria e a glicemia de jejum (r=0,479), circunfer?ncia da cintura (r=0,253), triglicer?deos (r=0,360), hemoglobina glicada (HbA1c) (r=0,250), Homeostasis model assessment ? insulin resistance (HOMA-IR) (r=0,223) e prote?na C reativa ultra-sens?vel (PCR-us) (r=0,427) (todos p<0,05). Na SM observamos inadequa??es na ingest?o de zinco e confirmamos comprometimento no status de zinco, caracterizadas por aumento do zinco no eritr?cito e maior zinc?ria, embora as concentra??es de zinco no plasma estejam dentro dos valores de refer?ncia. Altera??es dos fatores de risco cardiometab?licos influenciam na zinc?ria de pacientes com SM. / Metabolic syndrome (MS) is a multifactorial disease whose pathophysiological alterations might compromise zinc status. The aim of this study was to evaluate zinc status biomarkers and their associations with cardiometabolic risk factors in individuals with MS. This is a study case-control, developed with 88 adults and elderly with SM, according to the National Cholesterol Education Program - Adult Treatment Panel III (NCEP / ATP-III), and 37 individuals without MS or other clinical condition with influence on zinc status. Clinical and anthropometric assessments were performed and lipid, glycemic, and inflammatory profiles were also obtained. It was evaluated zinc intake, plasma zinc, erythrocyte zinc, and urinary zinc excretion levels, by atomic absorption spectrophotometry. Differences between groups were evaluated by regression models. Correlations were identified by Pearson coefficient (r). The average age of participants was 50 (11) years and 44 (11) years for the group of patients with MS and controls, respectively. The average energy intake was significantly higher in patients with MS (p = 0.003) and dietary intake in both groups was characterized as high percentage of protein intake, and a proper percentage of carbohydrate and fat intake. Zinc intake average was significantly lower in MS group compared with control group (6.57 (1.64) mg/day vs 9.37 (2.41) mg/day; p < 0,001). No significant differences were observed in plasma zinc levels (88.81(18.28) ?g/dL vs 87.82(17.44) ?g/dL; p > 0.05). It was found significantly higher erythrocyte zinc levels in the MS group (47.47(8.29) ?g/gHb vs 41.43(7.37) ?g/gHb;p < 0.001) independent from co-variable adjustments. Urinary zinc excretion level was significantly higher in the MS group (554.80(291.00-787.60) ?g/24h vs 375.40(197.60-597.50) ?g/24h; p = 0.008), and adjustments for age and sex explained 21% of the difference, (R2 = 0.21, p < 0.001). SM group were found significant associations between zincuria and fasting blood glucose level (r = 0.479), waist circumference (r = 0.253), triglyceride levels (r = 0.360), glycated hemoglobin (HbA1c) levels (r = 0.250), homeostatic model assessment - insulin resistance (HOMA-IR) (r = 0.223) and high-sensitivity C-reactive protein levels (hs-PCR) (r =0.427) (all p <0.05). In SM we confirmed inadequacies in zinc intake and confirmed impairments in zinc status, characterized by increasing the erythrocytes zinc and higher zincuria, although plasma zinc levels were within the reference values. plasm zinc levels into references values. Alterations in cardiometabolic risk factors influence zincuria in patients with MS.

Made available in DSpace on 2014-12-17T14:33:07Z (GMT). No. of bitstreams: 1 FabricioRC_DISSERT.pdf: 838962 bytes, checksum: 3096b614c5fa73cd030f8193624b3469 (MD5) Previous issue date: 2012-08-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Protozoa may be an important alternative food source for Calanoida copepods in these environments. Aiming to quantify the feeding preferences of N. cearensis by ciliates in the presence of cyanobacteria, in vitro experiments were conducted, using mixed cultures in different concentrations of total food for copepod. Two ciliates species (Paramecium sp. and Cyclidium sp.) and a cyanobacteria toxic strain (Microcystis aeruginosa) were offered as food. Previous experiments were done to identify the copepod s maximum ingestion rate through the use of a type II functional response model when each prey is offered separately. High maximum ingestion rate were found when those protists were offered as prey. N. cearensis showed significant preference for protozoal prey over the cyanobacterium tested both in low (corresponding 95.15% of the diet) and in high food concentration treatments (about 91.56% of the diet), preferring the bigger ciliate in lower concentrations (67.52% of the diet). The meaningful involvement of heterotrophic organisms in the zooplankton diet emphasis the microbial loop participation in the energy transition from copepods to higher trophic levels. This data contributes to understand the stability of existing trophic interactions in reservoirs subjected to eutrophication and assists trophic cascade studies in these environments / Protozo?rios podem ser uma importante fonte alternativa de alimento para cop?podos Calanoida em ambientes dominados por cianobact?rias. Com o objetivo de quantificar a prefer?ncia alimentar de Notodiaptomus cearensis por ciliados em presen?a de cianobact?rias, experimentos in vitro foram conduzidos, utilizando-se culturas mistas em diferentes concentra??es totais de alimento para o cop?podo. Duas esp?cies de ciliados (Paramecium sp. e Cyclidium sp.) e uma cepa t?xica de cianobact?ria (Microcystis aeroginosa) foram ofertados como alimentos. Experimentos pr?vios visando identificar as taxas de ingest?o m?xima do cop?podo atrav?s do uso de um modelo de resposta funcional do tipo II quando cada uma das presas ? ofertada separadamente tamb?m foram realizados. O cop?podo apresentou maior taxa de ingest?o m?xima quando ciliados s?o ofertados como presa. N. cearensis mostrou prefer?ncia significativa por protozo?rios em detrimento da cianobact?ria testada tanto em tratamentos com menor (correspondendo a cerca de 95,15% da dieta) quanto com maior concentra??o de alimento (cerca de 91,56% da dieta), preferindo o ciliado de maior tamanho nas menores concentra??es (67,52% da dieta). A participa??o significativa de organismos heterotr?ficos na dieta do zoopl?ncton d? maior ?nfase ? participa??o da al?a microbiana na passagem de energia para n?veis tr?ficos superiores. Tal dado colabora para o entendimento da estabilidade das intera??es tr?ficas existentes em reservat?rios sujeitos a eutrofiza??o e auxilia estudos de cascata tr?fica nesses ambientes

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-06-14T19:34:21Z No. of bitstreams: 1 2015 - Veronica Cristina Lopes Menezes.pdf: 1388664 bytes, checksum: eb95b2be98ffd5f3a96140f14377f8f2 (MD5) / Made available in DSpace on 2017-06-14T19:34:21Z (GMT). No. of bitstreams: 1 2015 - Veronica Cristina Lopes Menezes.pdf: 1388664 bytes, checksum: eb95b2be98ffd5f3a96140f14377f8f2 (MD5) Previous issue date: 2015-07-30 / CAPES / The distribution of estrogen receptors in brain structures that are envolved in the hidroelectrolyte balance such as the lamina terminalis (LT), subfornical organ (SFO) and dorsal raphe nucleus (DRN) demonstrated that estradiol can modulate important responses in body fluids. In the literature experimental data support that estrogen can increase the triptofan-hydroxilase type 2 , the main enzyme for the serotonin synthesis. The primary question here is whether or not differences in the baseline or stimulated intake are a function of different levels of circulating gonadal hormones in female ovariectomized rats. Female Wistar intact rats (~230 g) were previously aclimated in metabolic cages during 5 days and ad libitum access to water and hypertonic saline (1.8%) bottles and food. Room temperature was maintained at 22?2 ?C with 12:12 h light-dark cycle (lights off at 19:00). Rats were anesthetized with intraperitoneal injections of a mixture of ketamine (75 mg/kg) and xylazine (5 mg/kg) and then bilaterally ovariohysterectomized. There were four experimental groups: OVX (replaced with corn oil), 2,5 ?g/kg (E2 2,5), 10,0 ?g/kg (E2 10,0) and 40,0 ?g/kg (E2 40,0), daily during seven days, s.c. After 24 h of the surgery the hormonal replacement initiated (estradiol cypionate, EC, Pfizer, Animal Health). We did three experimental protocols: baseline evaluations, sodium depletion and fluid replacement. The estrogen replacement exibitted a dose dependent effect in the following parameters under basal conditions: daily body weight, daily urinary volume and daily food intake. After sodium depletion there were no difference in the urinary volume after 2 and 24 hours of the experiment. But after fluid reposition we observed a dose dependent effect in the ingestive behaviour of water and hypertonic saline intake in sodium depleted and control animals. Our data support that estradiol can alter the natriorexigenic and dipsogenic responses especially after sodium depletion depending of the estrogenic status. / A distribui??o de receptores estrog?nicos em estruturas centrais envolvidas na regula??o da homeostase hidroeletrol?tica como o ?rg?o vasculoso da l?mina terminal, n?cleo subfornicial, n?cleo dorsal da rafe indica que o estradiol pode atuar nessas estruturas em resposta a altera??es nos fluidos corporais. Nosso objetivo foi verificar se a reposi??o hormonal pode influenciar de maneira concentra??o-dependente o status hidroeletrol?tico e neuroend?crino de ratas castradas com reposi??o hormonal em diferentes doses de forma comparativa. Ratas Wistar (~230 g) foram previamente adaptadas, por 5 dias, em gaiolas metab?licas, com acesso ad libitum aos bebedouros volum?tricos de ?gua e salina hipert?nica e ao alimento, sendo mantidas sob ciclo claro-escuro de 12 horas em sala com temperatura controlada em 22??2 ?C. Ao final da adapta??o, as ratas previamente anestesiadas com cetamina (75 mg/kg) e xilazina (5 mg/kg) foram submetidas ? cirurgia de ovariectomia bilateral. Os animais foram divididos em 4 grupos: OVX, reposi??o com ?leo de milho), repostos com ?leo de milho cipionato de estradiol (E2) 2,5 ?g/kg (E2 2,5), 10,0 ?g/kg (E2 10,0) e 40 ?g/kg (E2 40,0). O tratamento de reposi??o foi feito pela via subcut?nea, diariamente durante 7 dias tendo sido iniciado no dia seguinte ? cirurgia. Foram realizados tr?s protocolos experimentais: avalia??o sob condi??es basais, deple??o de ?ons s?dio e reapresenta??o de fluidos. Neste estudo o estradiol apresentou efeito dose dependente nos seguintes par?metros sob condi??es basais: peso corporal di?rio, volume urin?rio di?rio, ingest?o de alimento di?rio. Ap?s deple??o de s?dio n?o houve diferen?a em rela??o ao volume urin?rio de 2 e de 24 horas ap?s o experimento. No entanto ap?s a reapresenta??o dos fluidos houve efeito dose-dependente no comportamento ingestivo de ?gua e de salina hipert?nica tanto nos animais depletados de s?dio quanto nos animais controles.Os dados suportam que o estradiol modula o comportamento ingestivo dos animais sob condi??es basais e ap?s a deple??o de s?dio.