COVID-19 has had far-reaching economic, social and health consequences, with vulnerable groups disproportionally affected. Even before the COVID-19 pandemic, concern was expressed about university students' mental health, with global data suggesting students are more vulnerable than the general population to mental disorders. Yet, it is unclear what the pandemic's impact has been on the mental health of students in South Africa. We examined the impact of COVID-19 on first-year students at two universities in South Africa by analysing changes in the prevalence and age-of-onset of three common mental disorders (namely major depressive episode, generalised anxiety disorder, and suicidal ideation) before and during the pandemic, and comparing these to changes between 2015 and 2017. Our analysis of cross-sectional survey data collected in 2015, 2017 and 2020 shows no clear or consistent pattern of increases in prevalence of common mental disorders following the start of the pandemic. Lifetime prevalence rates of common mental disorders among students have been steadily increasing since 2015, and where increases before and during COVID-19 were observed, they are not consistently larger than increases between 2015 and 2020. No significant changes were observed in the 12-month prevalence of common mental disorders before and during COVID-19, except for an increase in prevalence of depression at one institution, and a decrease in suicidal ideation at the other. Findings suggest that in the context of ongoing adversity and disruptions on South African university campuses in recent years, COVID-19 may be just one more stressor local students face and that its impact on student mental health may not have been as marked in South Africa compared to other regions. SIGNIFICANCE: • This study is the first to explore COVID-19's impact on university students' mental health in South Africa, using data collected before and during the pandemic. • High rates of psychopathology confirm the need for sustainable campus-based interventions to support student well-being. • Rates of mental disorders among students have been increasing since 2015, and increases observed in 2020 were no larger than those observed in prior years. • In the context of disruptions on university campuses in recent years, COVID-19 is just one more stressor for students, and its impact may not have been as marked in South Africa compared to other regions.

Abstract Introduction Drug-related crimes, especially drug trafficking, account for a large part of incarcerations not only in Brazil, but also worldwide. It is not clear whether the change in the drug law has contributed to the increase in the number of drug trafficking prisoners. Few studies have investigated gender differences and the growth of drug trafficking offenses in the Brazilian southern state of Rio Grande do Sul. Objective To investigate the growth of the prison population in the state of Rio Grande do Sul, emphasizing incarcerations for drug trafficking and gender differences. Method This was an ecological study using secondary data collected from official databases of the Brazilian National Penitentiary Department (Departamento Penitenciário [DEPEN]), affiliated with the Brazilian Ministry of Justice. Results Between 2006 and 2015, incarcerations increased by 27% (25% men, 83% women). Incarcerations for drug trafficking accounted for 11% of total arrests in 2006 (11% men, 20% women) and 45% in 2015 (47% men, 91% women), corresponding to an increase of 427% (415% among men, 723% among women). Conclusions Imprisonment for drug trafficking has increased considerably, especially among women. This may be due to factors such as: increase of drug trafficking, increase in the numbers of gangs in the state, and changes in the Brazilian drug law. These results highlight an emerging challenge in public health from the perspective of human rights and gender.

Objective: To estimate the 12-month prevalence of mental health services utilization (overall and by type of service sector), the adequacy of treatment provided, and sociodemographic correlates in the Argentinean Study of Mental Health Epidemiology (ASMHE). Methods: The ASMHE is a multistage probability household sample representative of adults in urban areas of Argentina. The World Health Organization World Mental Health Composite International Diagnostic Interview (WMH-CIDI) was used to evaluate psychiatric diagnosis and service utilization. Results: Among those with a disorder, 27.6% received any treatment in the prior 12 months. Of these, 78.3% received minimally adequate treatment using a broad definition and only 43.6% using a stringent definition. For individuals with a disorder, more services were provided by mental health professionals (17.7%) than by general medical professionals (11.5%) or non-healthcare sectors (2.6%). Younger individuals with low education and income were less likely to receive treatment; those never married and those with an anxiety or mood disorder were more likely to receive treatment. Among those in treatment, treatment was least adequate among younger individuals with low education and low income. Conclusions: Policies to increase access to services for mental health disorders in Argentina are needed, as is training for primary care practitioners in the early detection and treatment of psychiatric disorders.

ABSTRACT The rheological behavior of an aqueous suspension of silver nanoparticles stabilized with aminosilane-based surfactant flowing under confinement was investigated. Three stability levels were defined based on the zeta potential: high (41.73 mV, pH 4.3), medium (10.44 mV, pH 7.4), and low (0.74 mV, pH 8.6). Furthermore, the preliminary investigation showed that the surface charge remained positive, and the formation of agglomerates was not observed. Due to the particle coating and the ionization of the amino groups of the surfactant an electrosteric stabilization was evidenced. Shear rates ranging from 50 to 1000 s-1 and shear stresses between 0.02 and 0.2 Pa, at the temperatures of 15, 25 and 35 ºC, were evaluated with the nanofluid flowing in microchannels with a gap of 100, 300 and 500 µm. A trend to dilatant behavior was observed at high shear rate and a slit size of 500 µm, while Newtonian behavior was predominant at lower slit sizes. A reduction of 47.3% was noticed at 25 ºC with the variation in the slit size from 500 to 300 µm. Furthermore, the viscosity of the nanofluid decreased as much as 60% when the slit size was reduced from 500 to 100 µm.

RESUMO: O cálcio (Ca) é um macroelemento que faz parte da composição mineral da dieta de animais de companhia. Este macroelemento é considerado um cátion de forte capacidade alcalinizante e, de acordo com a fonte e quantidade inclusa, pode aumentar o pH urinário. Os sais de cálcio têm diferentes solubilidades e dependendo do ânion ao qual o cálcio está associado, pode ser mais ou menos absorvido e assim, alterar o pH da urina. O objetivo deste estudo foi avaliar os efeitos de duas fontes de cálcio na alcalinização do pH urinário, bem como a excreção de eletrólitos urinários e o equilíbrio ácido-básico de felinos. Foi selecionada uma dieta extrusada para gatos e adicionados 160mEq/kg de cálcio das fontes carbonato de cálcio (CaCO3) ou gluconato de cálcio (C12H22CaO14). No tratamento controle, não houve adição de fontes de cálcio. Foram utilizados nove gatos adultos, de raças mistas, em dois períodos experimentais, com seis repetições por tratamento. Os animais apresentavam idade média de 4,0±1,3 anos e peso corporal médio de 3,96±0,71kg. Estes permaneceram em gaiolas metabólicas em período de adaptação durante sete dias, seguido de coleta total de urina durante seis dias. Nestas amostras foram aferidos o volume, densidade, pH e concentração de cálcio (g/d). O equilíbrio ácido-básico foi avaliado por hemogasometria em amostras de sangue venoso. As duas fontes de cálcio alcalinizaram a urina (P<0,001). No entanto, o gluconato de cálcio apresentou menor potencial de alcalinização em comparação ao carbonato de cálcio (P<0,05). O cálcio urinário não foi afetado pelos tratamentos e representou menos de 0,5% da ingestão de Ca. O experimento demonstrou que o cálcio, apesar de ser um cátion alcalinizante e influenciador do EB da dieta, não pode ser avaliado individualmente, porque dependendo do ânion associado, pode apresentar maior ou menor influência no pH da urina de gatos.

ABSTRACT: Calcium is a macroelement that is part of the mineral composition of the diet of companion animals, and is considered a cation of strong alkalizing power, increasing urinary pH. Calcium salts have different solubilities and depending on the anion to which calcium is associated with, it can be more or less absorbed, modifying the pH of the urine. The aim of this study was to evaluate the efficiency of calcium sources on alkalinization of urinary pH, as well as excretion of urinary electrolytes and acid-base balance of adult cats. An extruded diet for cats was selected, and had 160mEq/kg of calcium from the sources of either calcium carbonate (CaCO3) or calcium gluconate (C12H22CaO14) added. In the control treatment there was no addition of calcium sources, resulting in three treatments. Nine adult cats were used, mixed breed, in two experimental periods, with six replicates per treatment. Animal average age was 4±1.3 years old and average weight was 3.96±0.71kg. The cats remained in metabolic cages for an adaptation period of seven days, followed by six days of urine total collection, with volume, density, pH and calcium concentration (g/d) measurements. The acid-base balance was studied by blood gas analysis of venous blood. The two sources of calcium alkalinized the urine (P<0.001). However, calcium gluconate had less alkalinization power compared to the calcium carbonate (P<0.05). Urinary calcium was not affected by treatments, and represented less than 0.5% of calcium intake. The experiment showed that calcium, although an alkaline cation and considered strong influencer of the EB of the diet, cannot be evaluated individually, because depending on its associated anion it may have greater or lesser influence on cats urine pH.

ABSTRACT Considering that thiol-containing enzymes like kinases are critical for several metabolic pathways and energy homeostasis, we investigated the effects of cystine dimethyl ester and/or cysteamine administration on kinases crucial for energy metabolism in the kidney of Wistar rats. Animals were injected twice a day with 1.6 µmol/g body weight cystine dimethyl ester and/or 0.26 µmol/g body weight cysteamine from the 16th to the 20th postpartum day and euthanized after 12 hours. Pyruvate kinase, adenylate kinase, creatine kinase activities and thiol/disulfide ratio were determined. Cystine dimethyl ester administration reduced thiol/disulfide ratio and inhibited the kinases activities. Cysteamine administration increased the thiol/disulfide ratio and co-administration with cystine dimethyl ester prevented the inhibition of the enzymes. Regression between the thiol/disulfide ratio, and the kinases activities were significant. These results suggest that redox status may regulate energy metabolism in the rat kidney. If thiol-containing enzymes inhibition and oxidative stress occur in patients with cystinosis, it is possible that lysosomal cystine depletion may not be the only beneficial effect of cysteamine administration, but also its antioxidant and thiol-protector effect.

Objective: Many studies correlate characteristics of family functioning and the development of drug addiction. This study sought to evaluate and compare the family environment styles of two groups of psychoactive substance users: 1) alcohol-only users and 2) crack-cocaine users. Methods: Three hundred and sixty-four users of alcohol, crack-cocaine, and other drugs, recruited from research centers in four Brazilian capitals participated in this study. Subjects were evaluated through the Family Environment Scale and the Addiction Severity Index, 6th version (ASI-6). ASI-6 t-scores were compared by analysis of variance (ANOVA) and post-hoc tests. A final model was obtained using a logistic regression analysis. All analyses were adjusted for partner, age, and psychiatric t-score. Results: We found a significant difference between groups in the cohesion subscale (p = 0.044). The post-hoc test revealed a difference of 1.06 points (95%CI 0.11-2.01) between groups 1 (6.45±0.28) and 2 (5.38±0.20). No significant between-group differences were observed in the other subscales. However, categorical analyses of variables regarding family dynamic showed that crack users more often reported that sometimes people in their family hit each other (30.4% vs. 13.2%, p = 0.007) and that people in their family frequently compared each other regarding work and/or school achievement (57.2% vs. 42.6%, p = 0.041). Conclusion: These results suggest that families of crack-cocaine users are less cohesive than families of alcohol users. This type of family environment may affect treatment outcome, and should thus be adequately approached.

A presente pesquisa teve por objetivo desenvolver uma modelagem capaz de identificar o perfil ideal de produtores terminadores de suínos utilizando a otimização de desempenho interativa, que se iniciou através da verificação qualitativa dos critérios considerados de maior relevância para o contexto decisório, gerando um diagnóstico contendo perguntas estruturadas fechadas que abrangem aspectos socioeconômicos acerca da atividade, até se chegar à concepção do modelo matemático capaz de traduzir os dados obtidos em informações quantitativas. Para a verificação, foi proposto um estudo prático para um universo de 120 produtores associados a uma cooperativa localizada no Rio Grande do Sul. Os resultados mostraram que, a partir da definição do perfil ideal, foi possível verificar que 82 produtores estão no grupo dos que obtiveram um desempenho “Bom”; sendo que, para 44, o resultado se encontra na faixa entre 86% e 90% do ideal, o que significa que a maioria possui condições a curto ou médio prazos de evoluir seu status para o considerado “Muito Bom”, onde apenas 12,5% dos produtores se encontram atualmente.

The present research aimed to develop a modeling capable of identifying the ideal profile of swine finishing producers using the interactive performance optimization, which began by verifying qualitative the criteria considered most relevant to the decision-making, generating a closed structured diagnosis that covers the socioeconomic aspects about the activity, until the design of a mathematical model able to translate the data obtained in quantitative information. For the verification, it was proposed a practical study for a universe of 120 members of a cooperative in the state of Rio Grande do Sul, Brazil. The results showed that, from the application and the definition of the ideal profile, it was possible to verify that 82 producers are in the group of those who have obtained a "Good" performance, and to 44 the result is in the range between 86% to 90% from the ideal, which means that most have short or medium-term conditions to evolve their status for the considered "Very Good", where only 12.5% of the producers are currently.

As moscas-das-frutas são as principais pragas da fruticultura mundial. Consideradas chaves para a produção de citros, torna-se necessário o seu monitoramento, visando a evitar os danos diretos. O experimento teve como objetivos conhecer a variação populacional de Anastrepha fraterculus e a relação de sua população com danos em pomares orgânicos de Citrus sinensis, cultivar Céu e de C. sinensis x Citrus reticulata tangor 'Murcott'. Os dados foram coletados em 2003 e 2004 durante o período de maturação dos frutos, na região do vale do Caí, RS, Brasil. O número de moscas-das-frutas foi registrado, semanalmente, por meio de armadilhas McPhail, contendo suco de uva, a 25%. Danos aos frutos foram determinados pela razão entre frutos sadios e frutos danificados pela mosca. Registros meteorológicos de temperatura, umidade relativa e precipitação pluviométrica foram obtidos, em estação meteorológica distante 30 km das áreas experimentais. Verificou-se que, em condições ideais de precipitação pluvial, maiores foram as populações de A. fraterculus, espécie predominante na região. A população estimada capaz de causar danos aos frutos variou de acordo com o cultivar, sendo a laranjeira 'Céu' a mais susceptível. Os maiores picos populacionais ocorrem na fase de mudança de coloração dos frutos. Porém, na fase de maturação, as moscas causaram os maiores danos, dada a intolerância dos frutos ao ataque. Conclui-se que a infestação dos frutos de citros por A. fraterculus está relacionada com espécie e cultivar e com fatores climáticos, principalmente com a precipitação pluvial. O monitoramento constante da população de mosca-das-frutas é importante na determinação da infestação na colheita.

Fruit flies (Diptera, Tephritidae) are the main pests of horticulture worldwide. Because they are considered key pests in citrus production, it is necessary to monitor them to avoid the direct damage. The objective of this experiment was to evaluate the population variation of Anastrepha fraterculus and the relationship of its population with damage in organic orchards of orange "Céu" cultivar and tangor (C. sinensis x Citrus reticulata) cv "Murcott". Data were collected over the maturation period, from January 2003 to September 2004, in the Caí Valley region, State of Rio Grande do Sul, Brazil. The number of fruit flies was recorded weekly by McPhail traps containing grape juice at 25%. Damageto the fruits were determined by the ratio between healthy fruits and fruit damaged by the flies. Meteorological records of temperature, relative humidity and rainfall were obtained from meteorological station 30 km away from the experimental areas. It was found that larger populations of A. fraterculus, the predominant species in the region, were found under ideal conditions of rainfall. The estimatedpopulation of fruit flies capable of causing damage to fruits varied according to the cultivar, in which orange cv 'Céu' was the most susceptible. The highest population peaks were found at the color changing phase of fruits. However, at the phase of fruit maturity, flies caused the greatest damage due to the fruits intolerance to the attack. It was concluded that the infestation of citrus fruits by A. fraterculus is related to the species, the cultivar and climatic factors, especially rainfall. Constant monitoring of fruit fly population is important in determining the infestation at harvest.

O presente trabalho teve como objetivo avaliar os aspectos ambientais e agronômicos na cultura do milho, características do solo e do material percolado decorrentes da associação de água residuária da suinocultura e adubação mineral, em longo prazo. A área experimental possui histórico de aplicação de água residuária da suinocultura, com experimentos conduzidos desde 2006, sendo este o sétimo ciclo de cultura conduzido na área. Foram aplicadas quatro doses de água residuária da suinocultura (0; 100; 200 e 300 m³ ha-1) associadas à ausência e presença de adubação mineral, consistindo em oito tratamentos. Os resultados obtidos foram submetidos à análise de variância, e as médias, comparadas pelo teste de Tukey, a 5% de significância. Conclui-se que a água residuária da suinocultura pode ser parcialmente utilizada como fertilizante alternativo, desde que o P e o Mn sejam complementados com adubação específica. Deve-se ter cuidado com o acúmulo de Fe+2, Cu+2 e Zn+2 no solo, e também para as concentrações de Fe+2, Cu+2, Zn+2, NO3- + NO2- e Na+ no percolado, que excederam os limites nas maiores doses de ARS aplicadas.

This study aimed to evaluate the agronomical and environmental aspects in corn, soil characteristics and leachate resulting from the material combination of swine wastewater and mineral fertilizer in the long run. The experimental area has a history of swine wastewater application for experiments conducted since 2006, this being the seventh crop cycle in the area. Four doses of swine wastewater (0; 100; 200 and 300 m³ ha-1) associated with presence and absence of mineral fertilizer were applied, consisting of eight treatments. The results obtained were subjected to variance analysis and means compared by Tukey test at 5% significance. We conclude that the swine wastewater can be partially used as an alternative fertilizer, since the P and Mn are complemented with specific fertilization. There must be carefulness about Fe+2, Cu+2 and Zn+2 accumulation in soil, and also to the concentrations of Fe+2, Cu+2, Zn+2, NO3- + NO2- and Na+ in leachate which exceeded the limits at the highest SWW applied levels.

A campilobacteriose genital bovina (CGB) é uma doença infectocontagiosa causada por Campylobacter fetus, determina infertilidade temporária, endometrite leve e aborto em fêmeas, além de aumentar o intervalo entre partos. A ocorrência de CGB entre rebanhos no Brasil tem variado muito entre as diferentes regiões. Com isso, o objetivo deste trabalho foi identificar, por meio da reação em cadeia da polimerase (PCR), a ocorrência de amostras positivas para C. fetus, oriundas de bovinos, no período de 1999 a 2010, no Rio Grande do Sul, e analisar a positividade em machos e fêmeas. Foram utilizadas 816 amostras procedentes de 37 municípios, localizados predominantemente nas mesorregiões sudoeste e centro ocidental rio-grandense, das quais 480 aspirados prepuciais (92 provenientes de duas centrais de inseminação artificial e 388 de estabelecimentos de criação - monta natural), 324 aspirados cervicais e conteúdo abomasal de 12 fetos bovinos abortados. Como resultado, 10,9% das amostras (89/816) foram positivas para C. fetus. Quando analisados os resultados em relação à origem das amostras, 6,5% (6/92) das coletadas de machos de centrais de inseminação foram positivas, e das obtidas de touros utilizados em monta natural, 9% (35/388). Já entre as fêmeas, esse percentual foi de 13,6% (44/324) e, nas amostras obtidas de fetos abortados, 33,3% (4/12) foram positivas. Quando analisados os 91 estabelecimentos de criação com monta natural e os 37 municípios, foram positivos 44,0% (40/91) e 63,2% (24/37), respectivamente. Com isso, foi demonstrada a importância da CGB para os rebanhos bovinos, e uma maior ocorrência de amostras positivas em fêmeas, quando comparadas às amostras provenientes de machos.

Bovine genital campylobacteriosis (BGC) is an infectious disease caused by Campylobacter fetus, which determines temporary infertility, mild endometritis, miscarriage in females and also increases the calving interval. The occurrence of BGC in the Brazilian herds has varied widely among regions. The aim of this study was to identify by polymerase chain reaction (PCR) the occurrence of C. fetus in bovines from Rio Grande do Sul (RS), Brazil using samples collected from1999 to 2010. A total of 816 samples from 37 counties localized predominantly in the Southwest and Central Western regions of the RS state were analyzed. Four hundred eighty preputial aspirated samples (92 from artificial insemination centers and 388 from farms that use natural mating) and 324 cervical aspirates and abomasal contents of 12 aborted fetuses were analyzed. As result, 10.9% (89/816) were positive for C. fetus. When the results were analyzed in relation to its origin, 6.5% (6/92) of the males samples from insemination centers were positive, and the ones from natural mating 9% (35/388) were positives. For the females, this percentage was 13.6% (44/324) of positivity, and the samples from the aborted fetuses 33.3% (4/12) were positive. When the 91 farms that used natural mating and the 37 counties were analyzed, it showed a positivity rate of 44.0% (40/91) and 63.2% (24/37), respectively. This study shows the importance of BGC for bovine herds, and a larger occurrence of positive samples among females when compared to male.

OBJECTIVES: To investigate the relative importance of common physical and mental disorders with regard to the number of days out-of-role (DOR; number of days for which a person is completely unable to work or carry out normal activities because of health problems) in a population-based sample of adults in the São Paulo Metropolitan Area, Brazil. METHODS: The São Paulo Megacity Mental Health Survey was administered during face-to-face interviews with 2,942 adult household residents. The presence of 8 chronic physical disorders and 3 classes of mental disorders (mood, anxiety, and substance use disorders) was assessed for the previous year along with the number of days in the previous month for which each respondent was completely unable to work or carry out normal daily activities due to health problems. Using multiple regression analysis, we examined the associations of the disorders and their comorbidities with the number of days out-of-role while controlling for socio-demographic variables. Both individual-level and population-level associations were assessed. RESULTS: A total of 13.1% of the respondents reported 1 or more days out-of-role in the previous month, with an annual median of 41.4 days out-of-role. The disorders considered in this study accounted for 71.7% of all DOR; the disorders that caused the greatest number of DOR at the individual-level were digestive (22.6), mood (19.9), substance use (15.0), chronic pain (16.5), and anxiety (14.0) disorders. The disorders associated with the highest population-attributable DOR were chronic pain (35.2%), mood (16.5%), and anxiety (15.0%) disorders. CONCLUSIONS: Because pain, anxiety, and mood disorders have high effects at both the individual and societal levels, targeted interventions to reduce the impairments associated with these disorders have the highest potential to reduce the societal burdens of chronic illness in the São Paulo Metropolitan Area.

Objective: To assess prevalence and correlates of family caregiver burdens associated with mental and physical conditions worldwide. Methods: Cross-sectional community surveys asked 43,732 adults residing in 19 countries of the WHO World Mental Health (WMH) Surveys about chronic physical and mental health conditions of first-degree relatives and associated objective (time, financial) and subjective (distress, embarrassment) burdens. Magnitudes and associations of burden are examined by kinship status and family health problem; population-level estimates are provided. Results: Among the 18.9-40.3% of respondents in high, upper-middle, and low/lower-middle income countries with first-degree relatives having serious health problems, 39.0-39.6% reported burden. Among those, 22.9-31.1% devoted time, 10.6-18.8% had financial burden, 23.3-27.1% reported psychological distress, and 6.0-17.2% embarrassment. Mean caregiving hours/week was 12.9-16.5 (83.7-147.9 hours/week/100 people aged 18+). Mean financial burden was 15.1% of median family income in high, 32.2% in upper-middle, and 44.1% in low/lower-middle income countries. A higher burden was reported by women than men, and for care of parents, spouses, and children than siblings. Conclusions: The uncompensated labor of family caregivers is associated with substantial objective and subjective burden worldwide. Given the growing public health importance of the family caregiving system, it is vital to develop effective interventions that support family caregivers.

The interoperability between knowledge organization systems (KOS) has become very important in recent years, in order to facilitate simultaneous searches in several databases or to merge different databases into one. The new standards for KOS design and development, the American Z39.19:2005 and the British 8723-4:2007, include detailed recommendations for interoperability. Also, there is a new ISO standard in preparation, the 25964-1 about thesauri and interoperability, which will be added to the above mentioned ones. The available technology provides tools for interoperability, e.g. formats and functional requirements for subject authority, as well as those for Semantic Web RDF/OWL, SKOS Core and XML. On the other hand, presently it is very hard to design and develop new KOS due to economical problems, so interoperability makes it possible to take advantage of the existing ones. In this work the basic concepts, models and methods recommended by the standards are reviewed, as well as several experiences on interoperability between KOS that have been documented.

La interoperabilidad entre distintos sistemas de organización del conocimiento (SOC) ha cobrado gran importancia en los últimos tiempos, con el propósito de facilitar la búsqueda simultánea en varias bases de datos o bien fusionar distintas bases de datos en una sola. Las nuevas normas para el diseño y desarrollo de SOC, la estadounidense Z39.19:2005 y la británica BS 8723-4:2007, incluyen recomendaciones detalladas para la interoperabilidad. También se encuentra en preparación una nueva norma ISO 25964-1 sobre tesauros e interoperabilidad que se agregará a las anteriores. La tecnología disponible proporciona herramientas para este fin, como son los formatos y requisitos funcionales de autoridades y las herramientas de la Web Semántica RDF/OWL, SKOS Core y XML. Por otro lado, actualmente es muy difícil diseñar y desarrollar nuevos SOC debido a los problemas económicos, de modo que la interoperabilidad hace posible aprovechar los SOC existentes. En este trabajo se revisan los conceptos básicos, los modelos y métodos recomendados por las normas, así como numerosas experiencias de interoperabilidad entre SOC que han sido documentadas.