bluuebunny/crossref_metadata_2025 huggingface dataset:
Níveis de células somáticas sobre a proteólise do queijo Mussarela
Authors: Coelho Karyne Oliveira , Mesquita Albenones José de , Machado Paulo Fernando , Oliveira Antonio Nonato de , Souza Cleusely Matias de , Meyer Paula Marques
Published: April 2013

Objetivou-se, com a realização deste trabalho, avaliar o efeito do nível de células somáticas sobre a microbiota e a proteólise do queijo Mussarela, durante o período de armazenamento. Foram selecionadas vacas com contagem de células somáticas ≤200mil células/mL; de > 200 a ≤400mil células/mL; de >400mil células/mL a ≤750mil células/mL e >750mil células/mL e que não tinham recebido tratamento com antimicrobianos nos dias que antecederam a coleta da matéria-prima. Os queijos produzidos foram avaliados após 1; 15 e 30 dias de armazenamento para a contagem de coliformes a 35ºC, coliformes a 45ºC, psicrotróficos e bactérias ácido lácticas. Paralelamente, foram determinados os índices de extensão e profundidade da proteólise. O experimento completo foi repetido quatro vezes e o delineamento experimental foi em blocos aleatórios. Na análise estatística, utilizou-se a análise de variância seguida do teste de Tukey, considerando p<0,05 como probabilidade mínima aceitável para diferença entre as médias. O leite com elevada contagem de células somáticas apresentou concentração menor de proteína e maior de nitrogênio não proteico. Observou-se diminuição das bactérias ácido lácticas no queijo elaborado com leite composto de células somáticas >750mil células/mL. Não obstante, ocorreu um aumento significativo na extensão e profundidade da proteólise durante o período de armazenamento, resultados observados nos queijos fabricados com o leite com células somáticas >400mil células/mL. Portanto, para se produzir um queijo Mussarela de boa qualidade torna-se necessário o controle da matéria prima, e esta deve apresentar células somáticas inferiores a 400mil células/mL.
Propriedades físicas e sensoriais da carne suína PSE
Authors: Caldara Fabiana Ribeiro , Santos Viviane Maria Oliveira dos , Santiago Juliana Cascão , Almeida Paz Ibiara Correia de Lima , Garcia Rodrigo Garófallo , Vargas Junior Fernando Miranda de , Santos Luan Sousa dos , Nääs Irenilza de Alencar
Published: April 2013

Objetivou-se avaliar as características físicas e sensoriais da carne suína PSE, suas correlações e os prejuízos causados para a indústria, em função de sua ocorrência. Em abatedouro comercial aferiu-se o pH das carcaças (n=1601) aos 45 minutos post mortem (pH45), classificou-as em PSE (pH45<5,8) ou normais (pH45≥5,8). Após 24 horas de resfriamento, foram coletadas amostras do músculo Longissimus dorsi de 26 carcaças PSE e 26 normais, que foram avaliadas quanto à coloração (L*, a*, b*), perda de exsudato, perda de peso por cozimento, força de cisalhamento, atributos sensoriais (maciez, suculência e palatabilidade) e composição centesimal. Foram avaliadas as correlações entre parâmetros físicos e sensoriais. A incidência de carnes PSE foi de 10,06%. O pH final, perda de peso por cozimento, força de cisalhamento e composição centesimal não diferiram entre os tipos de carne. A perda de exsudato foi, aproximadamente, 39% maior para carne PSE. O pH45 correlacionou-se, negativamente, com L* (R= -0,331) e b* (R= -0,528). A suculência correlacionou-se, positivamente, com a palatabilidade (R= 0,436) e maciez (R= 0,297) e, negativamente, com a perda de peso por cozimento (R= -0,326). A força de cisalhamento apresentou correlação positiva com perda de exsudato (R= 0,529) e negativa com maciez (R= -0,767). O prejuízo estimado em função da ocorrência de carnes PSE foi da ordem de R$340.800,00 anuais. Carnes PSE apresentam alterações negativas nas propriedades funcionais e sensoriais, relacionadas com a redução de sua capacidade de retenção de água, o que causa perdas consideráveis para a indústria processadora.
Leite instável não ácido: um problema solucionável?
Authors: Fischer Viviam , Ribeiro Maria Edi Rocha , Zanela Maira Balbinotti , Marques Lúcia Treptow , Abreu Alexandre Susenbach de , Machado Sandro Charopen , Fruscalso Vilmar , Barbosa Rosangêla Silveira , Stumpf Marcelo Tempel
Published: April 2013

O objetivo deste trabalho é apresentar os principais resultados da pesquisa sobre o leite instável não ácido ou LINA. A proporção de amostras de leite com estabilidade térmica, abaixo do mínimo exigido pela indústria brasileira, configura um sério problema, com uma ocorrência mais elevada durante os períodos de carência alimentar. Trata-se de um problema multifatorial, cujos fatores intervenientes são relacionados à execução do teste (concentração do álcool), ao manejo (alimentação, clima, relação homem-animal), ao animal (suscetibilidade ao estresse, potencial produtivo, estádio da lactação, sanidade, problemas digestivos e metabólicos, frações da caseína), entre outros. Existem dúvidas quanto à capacidade do teste do álcool em estimar a estabilidade térmica do leite. A indústria necessita de um teste rápido, de baixo custo e que realmente identifique o leite adequado ao processamento térmico. O manejo correto dos animais, aliado ao uso de parâmetros realistas de execução do teste do álcool, pode contribuir para melhorar a estabilidade do leite.
Farelo de mandioca na ensilagem de capim-elefante: fracionamento de carboidratos e proteínas e características fermentativas
Authors: Oliveira Aline Cardoso , Garcia Rasmo , Pires Aureliano José Vieira , Oliveira Hellenn Cardoso , Almeida Vitor Visintin Silva de , Veloso Cristina Mattos , Rocha Neto Aires Lima , Oliveira Ueslei Leonardo Cardoso
Published: April 2013

Objetivou-se determinar as frações que compõem os carboidratos e as proteínas, bem como as características fermentativas da silagem de capim-elefante, sem e com emurchecimento, e acrescida de farelo de mandioca. Foi adotado o esquema fatorial 4 x 2, com quatro repetições no delineamento inteiramente casualizado. Os fatores avaliados foram níveis de farelo de mandioca (0; 7,5; 15 e 22,5% MN) e emurchecimento (sem e com). Foram usados silos de PVC, com 50 cm de altura e 10cm de diâmetro para a produção das silagens. As frações de CHO (A+B1 e B2) e as frações nitrogenadas B3 e C foram influenciadas pela associação do emurchecimento aos níveis de farelo de mandioca, o que não ocorreu com as frações nitrogenadas (A e B1+B2) das silagens. A adição de farelo de mandioca reduziu linearmente a fração C dos carboidratos. No que concerne às características fermentativas das silagens, o pH apresentou comportamento quadrático. O nitrogênio amoniacal apresentou comportamento quadrático e linear decrescente para as silagens sem e com emurchecimento, respectivamente. A utilização do farelo de mandioca reduz a fração B2 e a porção de carboidratos indisponíveis. As principais frações proteicas das silagens estudadas são as frações A e B1+B2. O emurchecimento e a adição de farelo de mandioca melhoram o valor nutritivo e as características fermentativas das silagens estudadas.
Produção de metano entérico em pastagens tropicais
Authors: Berchielli Telma Teresinha , Messana Juliana Duarte , Canesin Roberta Carrilho
Published: April 2013

Na presente revisão, buscou-se apresentar os principais impactos ambientais causados pela pecuária, sobretudo, em relação às emissões de gases efeito estufa (GEE). Além disso, buscou-se apresentar possíveis formas de mitigar essas externalidades. A criação de bovinos, no Brasil, acontece de forma extensiva, muitas vezes em áreas com pastagem degradada e, portanto, de baixa produtividade. Isso possibilita à atividade uma oportunidade de redução do impacto causado ao meio ambiente, uma vez que ações tomadas, no sentido de melhorar o rendimento animal, devem resultar em um menor consumo de recursos naturais (terra e água) e maior eficiência do sistema digestivo animal. Os principais problemas apontados pelos pesquisadores, no que tange à pecuária extensiva, são o metano emitido pela fermentação entérica dos ruminantes, o óxido nitroso emitido pelos dejetos dos animais em pastejo e o dióxido de carbono trocado pelo solo e vegetação. Muitos fatores influenciam a produção de CH4 entérico dos ruminantes, inclusive o tipo de carboidrato fermentado, o sistema digestivo do animal, a quantidade e o tipo de alimentos consumidos. Diante do exposto, pesquisadores têm desenvolvido tecnologias para reduzir a emissão de metano, através da melhoria das práticas de manejo alimentar, manipulação ruminal, por meio de suplementação com monensina, lipídios, ácidos orgânicos e compostos de plantas. Outras estratégias de redução de metano que foram investigadas são: defaunação e vacinas, que buscam inibir micro-organismos metanogênicos e a metanogênese. Assim, a busca por sistemas de produção eficientes tem sido uma das perspectivas da pecuária mundial para reduzir a emissão de poluentes e intensificar a produção animal.
Uso da cana-de-açúcar na alimentação de ruminantes
Authors: Siqueira Gustavo Rezende , Roth Marcella de Toledo Piza , Moretti Matheus Henrique , Benatti João Marcos Beltrame , Resende Flávio Dutra de
Published: April 2013

Objetiva-se com essa revisão abordar os aspectos relevantes à utilização da cana-de-açúcar na alimentação de ruminantes. A cana-de-açúcar é uma forrageira que apresenta elevada produtividade de massa por área, o que representa a principal vantagem de sua utilização. Entretanto, o corte diário é um empecilho para sua adoção em muitas propriedades. Opções como o tratamento químico da cana-de-açúcar in natura ou a ensilagem são válidas, mas possuem limitações. A cana-de-açúcar sempre foi considerada uma forrageira de baixa qualidade nutricional. Nesta revisão serão tecidas considerações para interpretar essas limitações nutricionais com um novo aspecto. E por fim serão apresentados trabalhos científicos que mostram o potencial de uso da cana-de-açúcar como volumoso para ruminantes.
Curva de crescimento de ovinos Santa Inês no Vale do Gurgueia
Authors: Ó Alan Oliveira do , Rêgo Neto Aurino de Araújo , Santos Gleyson Vieira dos , Sarmento José Lindenberg Rocha , Biagiotti Daniel , Sousa José Ernandes Rufino de
Published: April 2013

Objetivou-se descrever o crescimento de ovinos Santa Inês no Vale do Gurgueia a partir da análise de modelos não lineares: Brody,Von Bertalanffy, Richards, Logístico e Gompertz. Após a definição do modelo de melhor ajuste, avaliou-se a influência de fatores ambientais (estação de nascimento, sexo, tipo de parto e idade da mãe ao parto) sobre os parâmetros da curva. Foram utilizados dados do desenvolvimento ponderal de 61 ovinos, do nascimento aos 350 dias de idade, no período de janeiro de 2009 a dezembro de 2010. Os parâmetros foram estimados por meio do NLIN do SAS. Os modelos de Von Bertalanffy, Richards, Logístico e Gompertz ajustaram bem os dados de crescimento, entretanto, os modelos de Brody e Richards apresentaram maior variação no Quadrado Médio dos Resíduos. Com base no gráfico de dispersão dos resíduos, constatou-se que o modelo de Gompertz apresentou ajuste ligeiramente superior ao modelo de Von Bertalanffy. A taxa de crescimento absoluto estimada demonstrou crescente até os 28 dias de idade. O efeito de sexo foi importante fonte de variação para o parâmetro A, bem como os efeitos de idade da mãe ao parto aos parâmetros B e K. As correlações estimadas entre os parâmetros A e K, B e K foram negativas. Efeitos ambientais mostraram-se importantes fatores que influenciam os parâmetros da curva de crescimento de ovinos Santa Inês no estado do Gurgueia.
Desempenho zootécnico de girinos de rã-touro com diferentes níveis de proteína e energia digestíveis
Authors: Seixas Filho José Teixeira de , Navarro Rodrigo Diana , Pereira Marcelo Maia , Mello Sílvia Conceição Reis Pereira , Lanna Eduardo Arruda Teixeira , Lima Jorge Luiz Pereira
Published: April 2013

A partir dos valores de digestibilidade de alguns ingredientes foram propostas dietas, com diferentes níveis de proteína e energia digestíveis, em esquema fatorial 3 x 3, destinadas a girinos de rã-touro para avaliar o desempenho zootécnico. O experimento, com duração de 60 dias, foi conduzido com 810 girinos, oriundos da mesma desova, distribuídos em 27 caixas de polipropileno, em uma densidade de 1girino/L. O delineamento experimental foi um esquema fatorial com três níveis de proteína digestível (27; 31 e 35%) e três níveis de energia digestível (2.700; 2.800 e 2.900kcal/kg) com três réplicas. Os parâmetros avaliados aos 60 dias foram ganho de peso, consumo da dieta, consumo em proteína da dieta, conversão alimentar, taxa de eficiência proteica e índice de sobrevivência. Os resultados foram submetidos à análise de variância e ao teste de Duncan (95% de precisão). Os resultados encontrados não apresentaram interação entre proteína e energia digestível para nenhum parâmetro avaliado. Em relação à proteína digestível, foram verificadas diferenças nos parâmetros consumo em proteína da dieta e taxa de eficiência proteica (TEP), o que demonstra ineficiência das dietas com altos valores proteicos. Deve-se oferecer aos girinos de rã-touro dietas com 27% de proteína digestível, por apresentarem melhor resultado para taxa de eficiência proteica e para consumo em proteína da dieta.
Early maternal experience shapes offspring performance in the wild
Authors: Burton Tim , McKelvey S. , Stewart D. C. , Armstrong J. D. , Metcalfe N. B.
Published: April 2013

Both the environments experienced by a mother as a juvenile and an adult can affect her investment in offspring. However, the implications of these maternal legacies, both juvenile and adult, for offspring fitness in natural populations are unclear. We investigated whether the juvenile growth rate and adult reproductive traits (length, body condition, and reproductive investment at spawning) of female wild Atlantic salmon (Salmo salar) were related to the growth and survival of their offspring. Adult salmon captured on their upstream migration were used to create experimental full‐sib clutches of eggs, which were mixed and then placed in artificial nests in a natural stream that lacked salmon due to a migration barrier. Four months later we resampled the stream to obtain family‐level estimates of offspring size and survival. Mothers that had grown slowly as juveniles (as determined by scalimetry) but had invested heavily in reproduction (egg production for a given body length) and were in relatively poor body condition (somatic mass for a given body length) at spawning produced the largest eggs. Larger eggs resulted in larger juveniles and higher juvenile survival. However, after controlling for egg size, offspring growth was positively related to maternal juvenile growth rate and reproductive investment. The predictors of offspring survival (i.e., reproductive success) varied with the juvenile growth rate of the mother: If females grew slowly as juveniles, their reproductive success was negatively related to their own body condition. In contrast, the reproductive success of females that grew quickly as juveniles was instead related positively to their own body condition. Our results show that maternal influences on offspring in the wild can be complex, with reproductive success related to the early life performance of the mother, as well as her state at the time of breeding.
Plant community structure mediates potential methane production and potential iron reduction in wetland mesocosms
Authors: Andrews S. E. , Schultz R. , Frey S. D. , Bouchard V. , Varner R. , Ducey M. J.
Published: April 2013

Wetlands are the largest natural source of methane to the atmosphere, but factors controlling methane emissions from wetlands are a major source of uncertainty in greenhouse gas budgets and projections of future climate change. We conducted a controlled outdoor mesocosm experiment to assess the effects of plant community structure (functional group richness and composition) on potential methane production and potential iron reduction in freshwater emergent marshes. Four plant functional groups (facultative annuals, obligate annuals, reeds, and tussocks) were arranged in a full‐factorial design and additional mesocosms were assigned as no‐plant controls. Soil samples from the top 10 cm were collected three times during the growing season to determine potential methane production and potential iron reduction (in unamended soils and in soils amended with 200 mM formate). These data were compared to soil organic matter, soil pH, and previously published data on above and belowground plant biomass. We found that functional group richness was less important than the presence of specific functional groups (reeds or tussocks) in mediating potential iron reduction. In our mesocosms, where oxidized iron was abundant and electron donors were limiting, iron reducing bacteria outcompeted methanogens, keeping methane production barely detectable in unamended lab incubations. When the possibility of re‐oxidizing iron was eliminated via anaerobic incubations and the electron donor limitation was removed by adding formate, potential methane production increased and followed the same patterns as potential iron reduction. Our findings suggest that in the absence of abundant oxidized iron and/or the presence of abundant electron donors, wetlands dominated by either reeds or tussocks may have increased methane production compared to wetlands dominated by annuals. Depending on functional traits such as plant transport and rhizospheric oxygenation capacities, this could potentially lead to increased methane emissions in some wetlands. Additional research examining the role these plant functional groups play in other aspects of methane dynamics will be useful given the importance of methane as a greenhouse gas.
Measurements of assimilable organic carbon (AOC) in high saline conditions using P17
Authors: Mun Eunjeong , Lee Sangyoup , Kim Inhyuk , Kwon Boksoon , Park Heedueng , Hong Seungkwan
Published: April 2013

Biofouling caused by the deposition or growth of microorganisms on the membrane surface is one of the major concerns in nanofiltration (NF) and reverse osmosis (RO) processes. Assimilable organic carbon (AOC) has been a useful index to assess the growth potential of bacteria. In the case of drinking water, the AOC assay method has been widely applied to estimate growth or regrowth potential of bacteria in distribution and storage systems. However, studies on AOC measurement for high salinity water samples such as brackish water and seawater are rather scarce. The objective of this research is to investigate the influence of water salinity on the conventional AOC assay method. AOC samples with different salt concentrations were prepared by varying NaCl concentration from 0 to 35,000 mg/L, while the acetate concentration was held at 100 μg/L. The number of cells produced in water samples was measured by the heterotrophic plate count (HPC) method using R2A agar. The result showed that the cell production of Pseudomonas fluorescens strain P17 and Spirillum strain NOX decreased with increasing salinity. Especially, the growth of Spirillum strain NOX was noticeably influenced by water salinity. To further observe the relation between acetate concentration and cell production in high salinity water, organic-free saline water samples were prepared by spiking NaCl in deionized (DI) water. The organic-free saline water samples were enriched with acetate of which concentration was varied to be 0–1,000 μg/L (as acetate). Also, P. fluorescens strain P17 was adjusted to high total dissolved solids (TDS) condition prior to being injected into the saline water samples. The result demonstrated that the amount of microorganisms increased with increasing acetate concentration. Although AOC measurement of saline water using Spirillum strain NOX seemed unacceptable, it was suggested that P. fluorescens strain P17 has the possibility to be used in measuring AOC in saline water. Moreover, the yield factor was altered as a result of reflecting salinity impact as the growth number of P. fluorescens strain P17 was unstable with high saline condition.
Exploring the need for rainwater tank maintenance: survey, review and simulations
Authors: Moglia Magnus , Tjandraatmadja Grace , Sharma Ashok K.
Published: April 2013

Rainwater tanks are a common feature of the urban landscape in Australia and globally. In Brisbane, Australia, provision of alternative water in new homes is mandatory and to meet this requirement rainwater tanks are considered an important option. The water savings of rainwater tanks can help defer investments in supply infrastructures. An emerging concern is that there is currently no mechanism in place for making sure that the household rainwater collection systems are maintained and in a good condition. In fact, in many locations, there is growing concern about whether the condition of this asset stock is adequate. The paper presents: a synthesis of required basic water tanks maintenance tasks; a short overview of published literature on householder motivations for maintenance; a synthesis of existing information about the condition of tanks, based on literature; simulation model results identifying the relationship between frequency of inspections and the (stationary) proportion of tanks with different types of problems; and the results of a survey to identify judgements about water tank maintenance in the region by professionals and plumbers. The paper concludes that there is a need for collecting more data and that mechanisms need to be in place to ensure the ongoing condition of tanks.
Household greywater use practices in Melbourne, Australia
Authors: Sinclair M. , O'Toole J. , Malawaraarachchi M. , Leder K.
Published: April 2013

Research on the potential of greywater reuse to reduce urban tap water demand has focused mainly on permanently installed greywater treatment or irrigation systems. These may be readily implemented in new housing developments, but experience in Australia shows their uptake by established households in urban areas is low. The majority of households employ simple and temporary methods for greywater collection and use, but their behaviour has not been well documented. We characterised the greywater use practices of over 1,000 Melbourne households during a 5-year period (2007 to 2011) which included 3 years of severe drought with stringent restrictions on outdoor tap water use. Greywater was most frequently collected from the laundry and bathroom, and generally used within 24 hours. Garden watering was the most common end use, and treatment of greywater to reduce microbial contamination was very rare. Volume estimates by householders suggest that on average around 10% of tap water used in the home was being collected for reuse. When drought conditions and water restrictions eased, over 40% of user households discontinued greywater use. Widespread adoption of permanent greywater collection, treatment and storage systems by households would be required to achieve a lasting effect on urban water consumption.
Research on the evaluation method of groundwater quantity and pollution vulnerability
Authors: Bai Liping , Wang Yeyao , Fang Huina , Liu Li , Zhou Youya , Yan Zengguang , Li Fasheng
Published: April 2013

Current research on groundwater vulnerability is aimed mainly at groundwater pollution vulnerability (GPV), and the vulnerability of groundwater quantity is seldom considered. It is important to carry out the groundwater vulnerability evaluation for the management of groundwater resources. This paper presents evaluation models and methods for assessing groundwater quantity and pollution vulnerability. The models and methods were used to evaluate the groundwater vulnerability in the plain area of Baotou, Inner Mongolia, China. The groundwater quantity vulnerability was assessed by computing the groundwater recharge rate, and the GPV was evaluated by simulating the migration time for pollutants traveling from ground surface to the aquifer. The research results could provide scientific support for the management of regional groundwater resources, prevention and control of groundwater pollution.
Rainwater harvesting and management – policy and regulations in Germany
Authors: Schuetze T.
Published: April 2013

This paper discusses the most important policies and regulations supporting the decentralized management, harvesting and utilization of rainwater in Germany, where such measures have been increasingly applied during the last few decades. The development and implementation of specific policies and regulations contributed significantly to that trend. They also work as incentives for the development of advanced technologies and businesses as well as the widespread and growing implementation of measures for decentralized rainwater management, harvesting and utilization by public and private actors. This development can generally be associated with environmental and economic concerns related with required adaptation to changes in climate, demographic structures and infrastructures as well as climate resilience including flood control and drought resistance. The addressed and supported measures can be assigned to the two focus areas ‘Decentralized rainwater harvesting and utilization’, aiming for saving of precious fresh water resources and centrally supplied drinking water, as well as ‘decentralized rainwater retention and management’, aiming for flood control and protection of existing infrastructures and ecosystems. The decentralized management of rainwater and its separation from combined sewer systems at the source is generally regarded as the state of the art and basic condition for sustainable municipal wastewater management.
Energy recovery potential using micro hydropower in water supply networks in the UK and Ireland
Authors: Corcoran Lucy , Coughlan Paul , McNabola Aonghus
Published: April 2013

The supply and treatment of water is a highly energy intensive process, resulting in large amounts of greenhouse gas emissions as well as incurring large economic costs. Both governments and water service providers worldwide recognise the need for more sustainable water supply systems. In recent years, the use of hydropower turbines within water supply networks has been shown as a viable option for electricity generation. Energy can be recovered in water supply networks at locations of excessively high flow or pressure without loss in the level of service to consumers. The control of pressure to prevent burst pipes and to maintain a reliable water supply service is a top priority for water service providers. This paper presents the results of an analysis of the potential of hydropower energy recovery within water distribution systems in the UK and Ireland. Pressure and flow data were analysed to determine the extent of the potential for energy recovery. The effect of flow rate variation on turbine selection and efficiency was investigated, as well as investment payback period. It was concluded that the sustainability of water supply can be improved through the implementation of small-scale hydropower turbines within water supply networks.
Evaluation of dynamic membrane formation and filtration models at constant pressure in a combined coagulation/dynamic membrane process in treating polluted river water
Authors: Xu Chunhua , Gao Baoyu , Cao Baichuan , Cheng Dandan , Yue Qinyan
Published: April 2013

In this study, a dynamic membrane (DM) was formed by flocs produced by river water pollutants reacting with polyaluminum chloride (PAC). The DM was used to separate the flocs from the mixed liquor at constant pressure. Two support media for the DM were tested: non-woven fabric filter and dacron mesh. The formation time of the DM was determined according to the critical flux. The formation process and filtration mechanisms were evaluated based on typical crossflow membrane fouling models and combinations of them. When a non-woven fabric filter was used as the support media, the formation time of the DM was 70 min at 4 cm water head drop (WHD) and 20 min at 8 cm WHD. When dacron mesh was used as the support media, the membrane formation required 100 min at 4 cm WHD and 70 min at 8 cm WHD. During DM formation on a non-woven fabric filter, the internal pore blocking plays the dominant role. But when dacron mesh is used as the support media, complete blocking and intermediate blocking dominate. After the formation of a DM, the combined models have good agreement with the experimental data compared with the typical filtration models.
A contribution to understanding stratigraphy of Lepenski Vir
Authors: Peric Slavisa , Nikolic Dubravka
Published: April 2013

This paper presents the results of the analysis of the documentation from the
excavations at the site of Lepenski Vir during two investigation campaigns in
1966. The focus is on the analysis of the vertical stratigraphy and
stratigraphic interrelations between the elements of the Mesolithic culture
of Lepenski Vir, i.e. the layers associated with the Lepenski Vir I and II
phases and the Neolithic settlement, in other words, the elements of the
Lepenski Vir III phase.
Necropolis on Bor lake: New reports on Bronze age burial
Authors: Kapuran Aleksandar , Miladinovic-Radmilovic Natasa
Published: April 2013

This article deals with the social and anthropological aspects of burial
rituals during the Middle Bronze Age in Timocka Krajina. Decades of
systematic research of necropolises and reconnaissance in the basin of the
Crni Timok proved an increase in number of sites around ore - rich areas of
the east Kucaj mountains as well as around Romuliana site and the fertile
valleys of Dzanovo polje (Map. 1). The quantitative increase in settlements
was reflected by the emergence of large necropolises, only three of which
have been systematically explored; those in Trnjani, Magura and Bor Lake
(Fig. 1; Plan 1). Analysis of geographical features of many settlements and
their position in relation to natural resources helped define two
communities, one of which carried out mining and metallurgical activities,
while the other group engaged in the production of food. Both groups lived in
the immediate vicinity and mutual dependence, functioning within a developed
market for copper production. During the exploration of the necropolis near
Bor Lake in 1997, the remains of burnt skeletons were collected from burial
structures 2/97 and 13/97 (Fig. 2; Plans 2 and 3). Anthropological analysis
of the cremated remains of the deceased showed that high temperatures were
used during the cremation process, which we assume could have only been
achieved in metallurgical furnaces. This is confirmed by the fact that the
skeletal fragments contain traces of melted metal, as well as finds of bronze
slag inside urns and grave structures in the necropolis in Trnjani (Figs. 3
and 4; Tables 1-4). Burial ritual of this kind was not proved by systematic
archaeological research of necropolises in the basin of Crni Timok, although
anthropological data collected from necropolises linked to metallurgical
settlements may indicate some guidelines in the ritual cremation of prominent
members of these communities.
Water supply system at Krsevica (4th century BC)
Authors: Popovic Petar , Vukadinovic Momir
Published: April 2013

Archaeological investigations of an urban settlement dated between the
beginning of the 4th and first decades of the 3rd century BC have been
conducted at the site Kale in Krsevica since the year 2001. Below the
acropolis and close to the Krsevica river segment of the complex with water
supply system, which could provide water for few thousand inhabitants has
been discovered. The system consists of basin for water filtering and
structure with barrel vault as reservoir. The chronological framework for
this intricate and unique complex is possible to establish only after
detailed analyses and further investigations (only around 6% of the entire
site has been investigated so far).
A Model for Critical Games Literacy
Authors: Apperley Tom , Beavis Catherine
Published: April 2013

This article outlines a model for teaching both computer games and videogames in the classroom for teachers. The model illustrates the connections between in-game actions and youth gaming culture. The article explains how the out-of-school knowledge building, creation and collaboration that occurs in gaming and gaming culture has an impact on students' understanding of their own lifeworlds. The authors demonstrate how the development of curricula around and with games and gaming cultures can incorporate and capitalise on approaches to learning and collaboration, design and identity that students have developed in their own gaming practices.
Professionalism in Student Online Social Networking: The Role of Educators
Authors: Chester A. , Kienhuis M. , Pisani H. , Shahwan-Akl L. , White K.
Published: April 2013

Social media now form a common part of university students' experience. Both at university and after graduation, in their personal and professional lives, social media offer opportunities for connection previously unavailable. The ubiquitous nature of social networking has brought with it professional and ethical issues that need to be addressed. Eprofessionalism, or professionalism in the digital media, has emerged as an important aspect of professional training across a range of disciplines. It is of particular importance in the field of health science due to the need to manage appropriate boundaries with clients. This article provides those involved in health science education with a brief introduction to eprofessionalism and social networking, a summary of the major research findings in this field, and a set of recommendations for initiating positive change in the university context.
Understanding Social Media Use as Alienation: A Review and Critique
Authors: Reveley James
Published: April 2013

The opportunities social media provide for agential expressions of subjectivity and experiential learning, relative to social media's role in reproducing digital-era capitalism, are the subject of keen debate. There is now a burgeoning academic literature which suggests that social media users are, to a greater or lesser degree, alienated by the activities of mega-corporations like Google and Facebook. Within this literature two broad perspectives are clearly identifiable. The first insists that social media platforms strongly alienate their users. To the extent that critical media scholars who advance this proposition are preoccupied with ideological hegemony, their work emblematises the idealist tendency of (old) media theorists that Dallas W. Smythe criticises. Contributors to the second perspective posit a trade-off between social media user alienation and exploitation. Not only is this idea inherently problematical, it does not go far enough towards resetting the analysis of social media back onto a materialist track. This article seeks to do just that.
The Management of Defective Resin Composite Restorations: Current Trends in Dental School Teaching in Japan
Authors: Lynch CD , Hayashi M , Seow LL , Blum IR , Wilson NHF
Published: April 2013

Aim:

The aim of this article is to investigate the contemporary teaching of the management of defective direct resin composite restorations in dental schools in Japan.

Methods:

A questionnaire relating to the teaching of the management of defective resin composite restorations was developed and e-mailed to 29 dental schools in Japan in 2010.

Results:

Completed responses were received from 19 of the 29 invited schools (response rate = 66%). Eighteen schools (95%) report that they included the teaching of repair of direct defective resin composite restorations in their dental school programs. Thirteen schools reported that they included both clinical and didactic instruction on the repair of direct resin composite restorations. Fourteen schools did not teach any mechanical roughening of the exposed resin composite restoration surface before undertaking a repair. The most commonly reported treatment was acid etching with phosphoric acid (12 schools). The most commonly taught material for completing repairs was a flowable resin composite (16 schools).

Conclusion:

The teaching of repair of defective resin composite restorations is well established within many Japanese dental schools, to a greater extent than in some other regions of the world. The impact of this teaching on subsequent clinical practices in Japan should be investigated. Furthermore, it is concluded that there is a need for much stronger leadership in operative and conservative dentistry, ideally at the global level, to resolve differences in key aspects of operative procedures such as repairs.
Porcelain Veneers as an Alternative for Esthetic Treatment: Clinical Report
Authors: Rotoli BT , Lima DANL , Pini NP , Aguiar FHB , Pereira GDS , Paulillo LAMS
Published: April 2013

This case report describes the restoration of the anterior dentition with porcelain laminate veneers. The advances in bonding of porcelain to tooth structure make this treatment a feasible alternative to restore teeth with alteration in shape and position in cases in which the esthetic demand is high. The rationale for various choices in this treatment protocol is detailed with reference to the pertinent literature. Thus, the clinical success of the technique depends on the correct identification of a case for which this treatment is appropriate and the successful execution of the clinical steps involved.
Longevity of Direct Restorations in Stress-Bearing Posterior Cavities: A Retrospective Study
Authors: Rho Y-J , Namgung C , Jin B-H , Lim B-S , Cho B-H
Published: April 2013

The aims of this retrospective clinical study were to compare the longevities of direct posterior amalgam restorations (AMs) and resin composite restorations (RCs) that were subjected to occlusal stresses and to investigate variables predictive of their outcome. A total of 269 AMs and RCs filled in Class I and II cavities of posterior teeth were evaluated with Kaplan-Meier survival estimator and multivariate Cox proportional hazard model. Seventy-one retreated restorations were reviewed from dental records. The other 198 restorations still in use were evaluated according to modified US Public Health Service (USPHS) criteria by two investigators. The longevity of RCs was significantly lower than that of AMs (AM = 8.7 years and RC = 5.0 years, p<0.05), especially in molars. The prognostic variables, such as age, restorative material, tooth type, operator group, diagnosis, cavity classification, and gender, affected the longevity of the restorations (multivariate Cox regression analysis, p<0.05). However, among the restorations working in oral cavities, their clinical performance evaluated with modified USPHS criteria showed no statistical difference between both restoratives. In contrast to the short longevity of RCs relative to AMs, the clinical performance of RCs working in oral cavities was observed to be not different from that of AMs. This suggests that once a RC starts to fail, it happens in a rapid progression. As posterior esthetic restorations, RCs must be observed carefully with periodic follow-ups for early detection and timely repair of failures.
A Two-Decision Model for Responses to Likert-Type Items
Authors: Thissen-Roe Anne , Thissen David
Published: April 2013

Extreme response set, the tendency to prefer the lowest or highest response option when confronted with a Likert-type response scale, can lead to misfit of item response models such as the generalized partial credit model. Recently, a series of intrinsically multidimensional item response models have been hypothesized, wherein tendency toward extreme response set is simultaneously estimated alongside one or more psychological constructs of interest. The multidimensional nominal response model (MNRM) is a divide-by-total model that allows person parameters for response sets, including extreme response set. The proportional thresholds model (PTM) is a difference model with response set parameters. The present study introduces a two-decision model (TDM) as an alternative to the MNRM and PTM and compares all three on data from assessments used in employee selection.
Audit of Prescribing Practices to Evaluate Rational Use of Medicines in the OPD of Orthopaedics in a Private Medical College Hospital
Authors: Afsan Mohammad , Haque MM Ekramul , Alam Muhammad Mahbubul , Noor Nushrat
Published: April 2013

Background: Prescribing patterns need to be evaluated periodically to increase the therapeutic efficacy, decrease adverse effects and provide feedback to prescribers. Like all other developing countries, irrational and inappropriate use of drugs is very common in Bangladesh. Objectives: The main objective of the prescription audit was to define the pattern of drug used in the outpatient department of orthopaedics. Methodology: This was a descriptive type of cross-sectional study. The study was conducted in the Outpatient Department (OPD) of Orthopaedics in a tertiary care private teaching hospital. Dhaka, Bangladesh in between January to March '2012. A total of 300 prescriptions were obtained with the help of a pre-inserted carbon paper in a special format using WHO core prescribing indicators and some additional indices. Results: The average number of drugs per encounter was 3.78 and no single drug was prescribed by generic name. Use of an antibiotic and an injection was in 6.67% and 3.33% of encounters respectively. Only 4.32% drugs were prescribed from national essential drug list (EDL). Percentage of encounters with a NSAID, an antiulcerant and a calcium preparation prescribed were 97%, 97.33% and 67.33% respectively. Conclusion: The patterns of drug prescribing in the OPD of orthopaedics did not fulfill the WHO criteria for rational use of medicine. DOI: http://dx.doi.org/10.3329/jssmc.v4i2.14399 J Shaheed Suhrawardy Med Coll, 2012;4(2):39-42
Risk Factors and Outcome of Obstructed Labour at a tertiary care Hospital
Authors: Islam Jinnat Ara , Ara Gulshan , Choudhury Farzana Rabee
Published: April 2013

Background: Obstructed labour is one of the most common preventable cause of maternal and prenatal morbidity and mortality in developing countries. Objective: The purpose of the present study was to determine the risk factors as well as to asses the outcome of obstructed labour. Method: This cross sectional study was conducted in the Department of Gynecology & Obstetrics at Shaheed Ziaur Rahman Medical College Hospital, Bogra during the period from January 2007 to December 2007. One hundred and five cases with features of obstructed labour were selected as per inclusion and exclusion criteria in a consecutive method. A detailed history included sociodemographic feature, obstetric history, features of obstruction, intrapartum events were recorded to detect risk factors. Condition of patients, mode of delivery, preoperative and post operative complications, maternal and fetal outcomes were recorded. Results: A total number of 3171 deliveries were conducted during this period and 132 cases of obstructed labour were found constituting an incidence of 4.2%. The highest frequency was found among the unbooked, primigravid patients that were illiterate or only having primary education level. The commonest cause was cephalo-pelvic disproportion (47.5%) followed by fetal malpostion (25.7%) and malpresentation (24.8%). The majority of the patients were between 25-29 years, caeserean section was the most common mode of delivery (78.09%). Maternal morbidity due to different complication accounted for 76.19% of the case while the fetal morbidity was 51.31% of the cases. The maternal mortality was 1% and prenatal mortality was 24.76%. Conclusion: In this study the incidence of obstructed labour was very high. The commonest cause was cephalo-pelvic disproportion followed by fetal malpostion and malpresentation. DOI: http://dx.doi.org/10.3329/jssmc.v4i2.14401 J Shaheed Suhrawardy Med Coll, 2012;4(2):43-46
Socio-demographic Characteristics of Drowning Cases Recorded At a Tertiary Care Hospital
Authors: Chowdhury Md Habibuzzaman , Rahman Md Mizanur , Hossain Md Gisan , Islam Md Rafiqul
Published: April 2013

Background: The autopsy diagnosis of drowning represents one of the major problems in forensic medicine. Objective: The purpose of the present study was to see the socio-economic characteristics of the drowning cases. Methodology: It was a retrospective study of 20 cases of drowning in 13 thanas of Dinajpur district during 1st January 2004 to December 2006. All the cases were autopsied in the mortuary of Dinajpur Medical College, Dinajpur. All the above may show signs of immersion on examination. Result: Total 20 cases were brought to the Department of Forensic Medicine at Dinajpur Medical College, Dinajpur. Considering the socio-economic status of the victim, it is found that higher frequency of drowning in the lower socio-economic growth. Highest age group is present in the 0-10 years which is 4 cases, 5 cases and 4 cases in the year of 2004, 2005 and 2006 respectively. Conclusion: In the conclusion, the study reveals that majority drowning cases are from low socio-economic condition with an early age group. DOI: http://dx.doi.org/10.3329/jssmc.v4i2.14418 J Shaheed Suhrawardy Med Coll, 2012;4(2):57-59
Rifampicin Resistance: Fitness Costs and the Significance of Compensatory Evolution
Authors: Hughes Diarmaid , Brandis Gerrit
Published: April 2013

Seventy years after the introduction of antibiotic chemotherapy to treat tuberculosis, problems caused by drug-resistance in Mycobacterium tuberculosis have become greater than ever. The discovery and development of novel drugs and drug combination therapies will be critical to managing these problematic infections. However, to maintain effective therapy in the long-term and to avoid repeating the mistakes of the past, it is essential that we understand how resistance to antibiotics evolves in M. tuberculosis. Recent studies in genomics and genetics, employing both clinical isolates and model organisms, have revealed that resistance to the frontline anti-tuberculosis drug, rifampicin, is very strongly associated with the selection of fitness compensatory mutations in the different subunits of RNA polymerase. This mode of resistance evolution may also apply to other drugs, and knowledge of the rates and mechanisms could be used to design improved diagnostics and by tracking the evolution of infectious strains, to inform the optimization of therapies.
Observation and Analysis of Particle Nucleation at a Forest Site in Southeastern US
Authors: Pillai Priya , Khlystov Andrey , Walker John , Aneja Viney
Published: April 2013

This study examines the characteristics of new particle formation at a forest site in southeastern US. Particle size distributions above a Loblolly pine plantation were measured between November 2005 and September 2007 and analyzed by event type and frequency, as well as in relation to meteorological and atmospheric chemical conditions. Nucleation events occurred on 69% of classifiable observation days. Nucleation frequency was highest in spring. The highest daily nucleation (class A and B events) frequency (81%) was observed in April. The average total particle number concentration on nucleation days was 8,684 cm−3 (10 < Dp < 250 nm) and 3,991 cm−3 (10 < Dp < 25 nm) with a mode diameter of 28 nm with corresponding values on non-nucleation days of 2,143 cm−3, 655 cm−3, and 44.5 nm, respectively. The annual average growth rate during nucleation events was 2.7 ± 0.3 nm·h−1. Higher growth rates were observed during summer months with highest rates observed in May (5.0 ± 3.6 nm·h−1). Winter months were associated with lower growth rates, the lowest occurring in February (1.2 ± 2.2 nm·h−1). Consistent with other studies, nucleation events were more likely to occur on days with higher radiative flux and lower relative humidity compared to non-nucleation days. The daily minimum in the condensation sink, which typically occurred 2 to 3 h after sunrise, was a good indicator of the timing of nucleation onset. The intensity of the event, indicated by the total particle number concentration, was well correlated with photo-synthetically active radiation, used here as a surrogate for total global radiation, and relative humidity. Even though the role of biogenic VOC in the initial nuclei formation is not understood from this study, the relationships with chemical precursors and secondary aerosol products associated with nucleation, coupled with diurnal boundary layer dynamics and seasonal meteorological patterns, suggest that H2SO4 and biogenic VOC play a role in nucleated particle growth at this site.