RESUMO
Amblyopia is a developmental disorder that results from abnormal visual experience in early life. Amblyopia typically reduces visual performance in one eye. We studied the representation of visual motion information in area MT and nearby extrastriate visual areas in two monkeys made amblyopic by creating an artificial strabismus in early life, and in a single age-matched control monkey. Tested monocularly, cortical responses to moving dot patterns, gratings, and plaids were qualitatively normal in awake, fixating amblyopic monkeys, with primarily subtle differences between the eyes. However, the number of binocularly driven neurons was substantially lower than normal; of the neurons driven predominantly by one eye, the great majority responded only to stimuli presented to the fellow eye. The small population driven by the amblyopic eye showed reduced coherence sensitivity and a preference for faster speeds in much the same way as behavioral deficits. We conclude that, while we do find important differences between neurons driven by the two eyes, amblyopia does not lead to a large scale reorganization of visual receptive fields in the dorsal stream when tested through the amblyopic eye, but rather creates a substantial shift in eye preference toward the fellow eye.
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There is substantial variation in the mean and variance of light levels (luminance and contrast) in natural visual scenes. Retinal ganglion cells maintain their sensitivity despite this variation using two adaptive mechanisms, which control how responses depend on luminance and on contrast. However, the nature of each mechanism and their interactions downstream of the retina are unknown. We recorded neurons in the magnocellular and parvocellular layers of the lateral geniculate nucleus (LGN) in anesthetized adult male macaques and characterized how their responses adapt to changes in contrast and luminance. As contrast increases, neurons in the magnocellular layers maintain sensitivity to high temporal frequency stimuli but attenuate sensitivity to low-temporal frequency stimuli. Neurons in the parvocellular layers do not adapt to changes in contrast. As luminance increases, both magnocellular and parvocellular cells increase their sensitivity to high-temporal frequency stimuli. Adaptation to luminance is independent of adaptation to contrast, as previously reported for LGN neurons in the cat. Our results are similar to those previously reported for macaque retinal ganglion cells, suggesting that adaptation to luminance and contrast result from two independent mechanisms that are retinal in origin.
Assuntos
Corpos Geniculados , Visão Ocular , Animais , Masculino , Corpos Geniculados/fisiologia , Células Ganglionares da Retina/fisiologia , Macaca , Retina , Estimulação Luminosa/métodos , Vias Visuais/fisiologiaRESUMO
Titanium and its alloys are mainly used in manufacturing dental implants. The fact that titanium implants are immunologically very effective, new methods are being experimented to achieve utmost success rate as a biomaterial. One fundamental indicator for clinical achievement of implant is the decision of composition decided for the implant with the objective to improve osseointegration. The main objective of this study was to explore literature on dental materials used for implants, contrast them with titanium dental implants, with the aim to improve osseointegration and mechanical quality using Ti-Ga-Si dental implant.
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Although currently exotic to New Zealand, the potential geographic distribution of Amblyomma americanum (L.), the lone star tick, was modelled using maximum entropy (MaxEnt). The MaxEnt model was calibrated across the native range of A. americanum in North America using present-day climatic conditions and occurrence data from museum collections. The resulting model was then projected onto New Zealand using both present-day and future climates modelled under two greenhouse gas emission scenarios, representative concentration pathways (RCP) 4.5 (low) and RCP 8.5 (high). Three sets of WorldClim bioclimatic variables were chosen using the jackknife method and tested in MaxEnt using different combinations of model feature class functions and regularization multiplier values. The preferred model was selected based on partial receiver operating characteristic tests, the omission rate and the lowest Akaike information criterion. The final model had four bioclimatic variables, Annual Mean Temperature (BIO1), Annual Precipitation (BIO12), Precipitation Seasonality (BIO15) and Precipitation of Driest Quarter (BIO17), and the projected New Zealand distribution was broadly similar to that of Haemaphysalis longicornis Neumann, New Zealand's only livestock tick, but with a more extensive predicted suitability. The climate change predictions for the year 2050 under both low and high RCP scenarios projected only moderate increases in habitat suitability along the mountain valleys in the South Island. In conclusion, this analysis shows that given the opportunity and license A. americanum could and would successfully establish in New Zealand and could provide another vector for theileriosis organisms.
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Distribuição Animal , Clima , Ecossistema , Ixodidae , Animais , Mudança Climática , Entropia , Modelos Teóricos , Nova ZelândiaRESUMO
A 53-year-old woman is admitted with a serum creatinine of 16 mg/dl. Seven months earlier, she was diagnosed with heart failure and started on several medications, including Hydralazine. Laboratory studies revealed the presence of dual Anti-Neutrophil Cytoplasmic Antibodies (anti-MPO and anti-PR3), anti-nuclear and anti-histone antibodies. The clinical diagnosis was Drug-Induced ANCA Vasculitis (DIAV). Kidney histology, however, did not reveal crescents, but showed characteristic features of Alport's syndrome.
RESUMO
The potent antifungal agent sesquiterpenes and serotonin 5-HT2C agonist ascotricin were produced by a newly isolated deep-sea fungus Ascotricha sp. This fungus was isolated from deep-sea sediment collected at a depth of 1235 m and characterized. Piezotolerance was successfully tested under high pressure-low temperature (100 bar pressure and 20ºC) microbial cultivation system. Production of secondary metabolites was enhanced at optimized culture conditions. The in-vivo antifungal activity of sesquiterpenes was studied using the Caenorhabditis elegans - Candida albicans model system. The sesquiterpenes affected the virulence of C. albicans and prolonged the life of the host C. elegans. These findings suggest that sesquiterpenes are attractive antifungal drug candidates. The 5-HT2C receptor agonist is a potential target for the development of drugs for a range of central nervous system disorders. The interaction of 5-HT2C agonist ascotricin with the receptor was studied through bioinformatic analysis. The in silico molecular docking and molecular dynamic simulation studies demonstrated that they fit into the serotonin 5-HT2C active site and the crucial amino acid residues involved in the interactions were identified. To our knowledge, this is first report of in vivo antifungal analysis of sesquiterpenes and in silico studies of serotonin 5-HT2C receptor-ascotricin complex.
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The North American distributional potential of the recently invaded tick, Haemaphysalis longicornis, was estimated using occurrence data from its geographic range in other parts of the world and relevant climatic data sets. Several hundred candidate models were built using a correlative maximum entropy approach, and best-fitting models were selected based on statistical significance, predictive ability, and complexity. The median of the best-fitting models indicates a broad potential distribution for this species, but restricted to three sectors-the southeastern United States, the Pacific Northwest, and central and southern Mexico.
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Distribuição Animal , Espécies Introduzidas , Ixodidae/fisiologia , Infestações por Carrapato , Animais , América do NorteRESUMO
BACKGROUND: Dissociation between caloric and head impulse test results in patients with vestibular disorders has been well documented since the introduction of video head impulse testing. Prior to the introduction of video head impulse testing, vestibular diagnostic services relied mainly on caloric testing, and it is now known that the caloric testing shows more positive results than video head impulse testing. A dissipation model was proposed to explain this dissociation.Case reportsThis paper presents two cases in which caloric testing indicated an absent or significantly reduced response on the horizontal semicircular canal plane but video head impulse testing showed near-normal or normal vestibulo-ocular reflex gain on the same plane. CONCLUSION: This report supports the dissipation theory and questions the functional relevance of canal paresis values calculated from caloric test results.
Assuntos
Testes Calóricos , Teste do Impulso da Cabeça , Canais Semicirculares/anormalidades , Doenças Vestibulares/diagnóstico , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vertigem/diagnóstico , Doenças Vestibulares/fisiopatologia , Vestíbulo do Labirinto/fisiopatologia , Gravação em VídeoRESUMO
The commensal oral microbial flora has evolved with the human host to support colonization of the various intraoral sites without triggering a significant immune response. In exchange, the commensal microbes provide critical protection against invading pathogens. The intrinsic ability of the oral flora to create a symbiotic microbial community with the host can be disturbed, selecting for the overgrowth of a dysbiotic community that can result in dental diseases, such as caries and periodontitis. Although the mechanisms of molecular pathogenesis in oral diseases are well characterized, much less is known about the molecular mechanisms used by the commensal flora to maintain oral health. Here we focus on the commensal species Streptococcus sanguinis, which is found in abundance in the early oral biofilm and is strongly correlated with oral health. Streptococcus sanguinis exhibits a variety of features that make it ideally suited as a model organism to explore the molecular basis for commensalism. As such, this review will describe our current mechanistic understanding of S. sanguinis commensalism and speculate upon its molecular traits that may be exploitable to maintain or restore oral health under conditions that would otherwise lead to disease.
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Boca/microbiologia , Streptococcus sanguis/genética , Streptococcus sanguis/fisiologia , Simbiose , Biofilmes/crescimento & desenvolvimento , Cárie Dentária , Humanos , Periodontite , Streptococcus mutans/fisiologia , Streptococcus sanguis/crescimento & desenvolvimentoRESUMO
Pethia sanjaymoluri, a new cyprinid, is described from the Pavana and Nira tributaries of Bhima River, Krishna drainage, Maharashtra, India. It can be distinguished from congeners by a combination of characteristics that includes an incomplete lateral line, absence of barbels, upper lip thick and fleshy, 23-25 lateral series scales, 7-12 lateral-line pored scales, 10 predorsal scales, 11-14 prepelvic scales, 17-20 pre-anal scales, 4½ scales between dorsal-fin origin and lateral line, four scales between lateral line and pelvic-fin origin, 8-15 pairs of serrae on distal half of dorsal-fin spine, 12-14 branched pectoral-fin rays, 4 + 26 total vertebrae, 4 + 5 predorsal vertebrae, 4 + 13 abdominal vertebrae, 13 caudal vertebrae and a unique colour pattern comprising a humeral spot positioned below the lateral line and encompassing the third and fourth lateral-line scales and one scale below, one caudal spot on 17th-21st lateral-line scales with a yellow hue on its anterior side and apical half of dorsal fin studded with melanophores making the fin tip appear black. Genetic analysis based on the mitochondrial cytochrome b gene sequence suggests that the species is distinct from other known species of Pethia for which data are available.
Assuntos
Cyprinidae/classificação , Animais , Biodiversidade , Cor , Cyprinidae/anatomia & histologia , Cyprinidae/genética , Genes Mitocondriais , Índia , Masculino , Filogenia , RiosAssuntos
Vírus da Hepatite A/genética , Hepatite A/líquido cefalorraquidiano , Mielite/virologia , RNA Viral/líquido cefalorraquidiano , Anticorpos Antivirais/sangue , Criança , Hepatite A/complicações , Hepatite A/diagnóstico , Vírus da Hepatite A/imunologia , Humanos , Imunoglobulina M/sangue , Imunoglobulina M/líquido cefalorraquidiano , Icterícia/virologia , Imageamento por Ressonância Magnética , Masculino , Mielite/líquido cefalorraquidiano , Reação em Cadeia da PolimeraseRESUMO
OBJECTIVES: The effect of aspirin upon platelet function is well documented although experimental studies suggest that aspirin may also affect oxidative stress, vascular inflammation, endothelial dysfunction and dysglycaemia. The optimal dose of aspirin for cardiovascular protection in type 2 diabetes is still debated. We examined the effects of different doses of aspirin upon these novel markers of cardiovascular risk and any association between aspirin-mediated changes in these markers. METHODOLOGY: Subjects with type 2 diabetes attended for baseline evaluation including BMI, glycaemic and lipid markers, endothelial function (photoplethysmography), insulin resistance (HOMA), inflammation (sVCAM-1 and Hs-CRP) and markers of oxidative stress [total anti-oxidant status (TAOS and FRAP), whole blood total glutathione (GSH) assays]. Subjects then received in random, sequential, blinded fashion aspirin 75 mg day(-1) , aspirin 300 mg day(-1) , aspirin 3.6 g day(-1) or placebo for 2 weeks with a 2-week washout. The above investigations were repeated after each intervention. Aspirin-related changes compared with placebo were analysed using repeated measures ANOVA. RESULTS: Subjects = 17 (M - 12; F - 5), mean age - 57.4 ± 9.1 years (mean ± 1 SD), HbA1c - 63 ± 13 mmol mol(-1) (7.9 ± 1.2%), total cholesterol 4.57 ± 1.01 mmol l(-1) . At baseline TAOS value was 59.3 ± 9.7 µM AEAC (Ascorbate Equivalent Anti-oxidant Concentration), glutathione 302.2 ± 183.3 mmol l(-1) and FRAP 0.86 ± 0.23 mM FeII. None of the aspirin doses had a significant impact upon BMI, blood pressure, lipid parameters, insulin sensitivity (HOMA), FRAP, TAOS, GSH, endothelial function, glycaemic control (fructosamine) or inflammation (sVCAM-1 and HsCRP). CONCLUSIONS: Aspirin exhibited no significant dose-dependent effect on markers of vascular inflammation, oxidative stress, insulin resistance and endothelial function (photoplethysmography) when used in type 2 diabetes over a 2-week period. ( CLINICAL TRIALS REGISTRATION: NCT00898950, EUDRACT:2004-001418-14).
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Aspirina/administração & dosagem , Diabetes Mellitus Tipo 2/prevenção & controle , Angiopatias Diabéticas/prevenção & controle , Hipoglicemiantes/administração & dosagem , Adulto , Idoso , Biomarcadores/metabolismo , Glicemia/metabolismo , Pressão Sanguínea/fisiologia , Relação Dose-Resposta a Droga , Endotélio Vascular/efeitos dos fármacos , Feminino , Glutationa/metabolismo , Humanos , Resistência à Insulina/fisiologia , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/efeitos dos fármacos , Vasculite/prevenção & controleRESUMO
This study compares the internal fit and marginal adaptation of copy milled Zirconia copings with Nickel-Chromium (Ni-Cr) copings fabricated using a lost wax technique before and after ceramic veneering. A standardized metal master die simulating a prepared crown was fabricated and twenty impressions of the metal die were made and poured with die stone. Wax patterns were made on ten dies and cast while light cure resin patterns were made on the other ten dies for copy milling the Zirconia copings. Five specimens from each group were subjected to ceramic veneering. All the test specimens were luted on to the fresh dies, embedded in dental plaster, sectioned and image analysis done using scanning electron microscopy. Thereafter statistical analysis is done using student t-test. The linear measurements for internal fit and marginal discrepancy were increased for Zirconia compared with Ni-Cr copings. The difference in the values of all the specimens of all the groups were not statistically significant (P > 0.05) except the values comparing the internal fit of Zirconia and Ni-Cr copings before ceramic veneering (P < 0.001) which was statistically significant. The internal fit and marginal adaptability of Ni-Cr copings were found to be better than the Copy milled Zirconia copings but internal fit and marginal adaptability deteriorated after ceramic veneering.
Assuntos
Ligas de Cromo , Coroas , Adaptação Marginal Dentária , Porcelana Dentária , Ligas Metalo-Cerâmicas , Facetas Dentárias , Humanos , Níquel , ZircônioRESUMO
Studies on the mechanisms of mineralization of connective tissues, have gained momentum in the recent past. In the present study, Biomimetic mineralization of modified fish scale collagen in vitro is reported. The fish scale collagen was crosslinked with 3-Aminopropyl triethoxysilane and the crosslinked collagen (FCSi) was characterized using conventional methods. The biomimetic mineralization capacity of FCSi was evaluated in SBF solution for 7 days. Formation of hydroxyapatite crystals on the matrix in vitro has been confirmed by FTIR, XRD and SEM-EDAX techniques. The FCSi may be used as a scaffold in bone tissue engineering and as an osteoinductive material in experimental animal models before applying clinically.
Assuntos
Materiais Biomiméticos/química , Colágeno/química , Reagentes de Ligações Cruzadas/química , Minerais/química , Silanos/química , Animais , Varredura Diferencial de Calorimetria , Colágeno/ultraestrutura , Peixes , Microscopia Eletrônica de Varredura , Propilaminas , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Difração de Raios XRESUMO
BACKGROUND: School leavers with intellectual disabilities (ID) often face difficulties in making a smooth transition from school to college, employment or more broadly to adult life. The transition phase is traumatic for the young person with ID and their families as it often results in the loss of friendships, relationships and social networks. METHOD: The aim of this study was to explore the family carers' views and experiences on transition from school to college or to adult life with special reference to ethnicity. Forty-three families (consisting of 16 White British, 24 Pakistani, 2 Bangladeshi and one Black African) were interviewed twice using a semi-structured interview schedule. The carers were interviewed twice, Time 1 (T1) and Time 2 (T2), T2 being a year later to observe any changes during transition. RESULTS: The findings indicate that although transition planning occurred it was relatively later in the young person's school life. Parents were often confused about the process and had limited information about future options for their son or daughter. All family carers regardless of ethnicity, reported lack of information about services and expressed a sense of being excluded. South Asian families experienced more problems related to language, information about services, culture and religion. CONCLUSIONS: The majority of families lacked knowledge and awareness of formal services and the transition process. Socio-economic status, high levels of unemployment and caring for a child with a disability accounted for similar family experiences, regardless of ethnic background. The three key areas relevant for ethnicity are interdependence, religion and assumptions by service providers.
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Cuidadores/psicologia , Etnicidade/psicologia , Deficiência Intelectual/etnologia , Deficiência Intelectual/psicologia , Comportamento Social , Aculturação , Adolescente , Adulto , Povo Asiático/psicologia , População Negra/psicologia , Emprego/psicologia , Feminino , Humanos , Acontecimentos que Mudam a Vida , Masculino , Pesquisa Qualitativa , Instituições Acadêmicas , Apoio Social , Reino Unido , População Branca/psicologia , Adulto JovemRESUMO
Hydrologic and soil-hydrologic variables were evaluated retrospectively as potential risk factors for canine leptospirosis in Kansas and Nebraska using Geographic Information Systems (GIS). The sample included 94 positive and 185 negative dogs for leptospirosis predominantly based on PCR test for leptospires in urine. Hydrologic variables for the region were derived from National Hydrographic Dataset, National Flood Hazard Layer, National Wetlands Inventory; and soil-hydrologic variables from Soil Survey Geographic Database around geocoded addresses of case/control locations. Multivariable logistic models were used to determine association between hydrologic and soil-hydrologic variables and test status. Distance from water features (OR=0.82; 95% CI=0.79, 0.86), hydrologic density (OR=2.80; 95% CI=1.58, 4.96) and frequently flooded areas (OR=4.05; 95% CI=2.17, 7.55) within 2500 m surrounding case/control locations were significant risk factors for canine leptospirosis. Vaccination for dogs that live closer to water features, landscapes dominated by water features and frequent floods should be considered for leptospirosis prevention.
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Doenças do Cão/microbiologia , Leptospira/crescimento & desenvolvimento , Leptospirose/veterinária , Microbiologia da Água , Zoonoses/microbiologia , Animais , Estudos de Casos e Controles , Doenças do Cão/epidemiologia , Cães , Sistemas de Informação Geográfica , Kansas/epidemiologia , Leptospirose/epidemiologia , Leptospirose/microbiologia , Modelos Logísticos , Nebraska/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Zoonoses/epidemiologiaRESUMO
Associations of housing, population, and agriculture census variables, and presence near public places were retrospectively evaluated as potential risk factors for canine leptospirosis using Geographic Information Systems (GIS). The sample population included 94 dogs positive for leptospirosis based on a positive polymerase chain reaction test for leptospires on urine, isolation of leptospires on urine culture, a single reciprocal serum titer of 12,800 or greater, or a four-fold rise in reciprocal serum titers over a 2-4 week period; and 185 dogs negative for leptospirosis based on a negative polymerase chain reaction test and reciprocal serum titers less than 400. Multivariable logistic regressions revealed different risk factors among different census units; however, houses lacking complete plumbing facilities [OR=2.80, 95% C.I.=1.82, 4.32 (census unit, block group); OR=1.36, 95% C.I.=1.28, 1.45 (census tract); OR=3.02, 95% C.I.=2.60, 3.52 (county)]; and poverty status by age (18-64) [OR=2.04, 95% C.I.=1.74, 2.39 (block group); OR=1.53, 95% C.I.=1.41, 1.67 (census tract); and OR=1.62, 95% C.I.=1.50, 1.76 (county)] were consistent risk factors for all census units. Living within 2500 m of a university/college and parks/forests were also significantly associated with leptospirosis status in dogs. Dogs that live under these circumstances are at higher risk for leptospirosis and pet owners should consider vaccination.
Assuntos
Doenças do Cão/epidemiologia , Leptospira/isolamento & purificação , Leptospirose/veterinária , Testes de Aglutinação/veterinária , Animais , Estudos de Casos e Controles , Censos , Cidades , DNA Bacteriano/genética , Doenças do Cão/sangue , Doenças do Cão/urina , Cães , Feminino , Sistemas de Informação Geográfica , Habitação , Atividades Humanas , Humanos , Kansas/epidemiologia , Leptospirose/sangue , Leptospirose/epidemiologia , Leptospirose/urina , Modelos Logísticos , Masculino , Nebraska/epidemiologia , Reação em Cadeia da Polimerase/veterinária , Estudos Retrospectivos , Fatores de Risco , Estações do Ano , Fatores Socioeconômicos , População UrbanaRESUMO
Associations of land cover/land use variables and the presence of dogs in urban vs. rural address locations were evaluated retrospectively as potential risk factors for canine leptospirosis in Kansas and Nebraska using Geographic Information Systems (GIS). The sample included 94 dogs positive for leptospirosis predominantly based on a positive polymerase chain reaction test for leptospires in urine, isolation of leptospires on urine culture, a single reciprocal serum titer of 12,800 or greater, or a four-fold rise in reciprocal serum titers over a 2-4 weeks period; and 185 dogs negative for leptospirosis based on a negative polymerase chain reaction test and reciprocal serum titers less than 400. Land cover features from 2001 National Land Cover Dataset and 2001 Kansas Gap Analysis Program datasets around geocoded addresses of case/control locations were extracted using 2500m buffers, and the presence of dogs' address locations within urban vs. rural areas were estimated in GIS. Multivariate logistic models were used to determine the risk of different land cover variables and address locations to dogs. Medium intensity urban areas (OR=1.805, 95% C.I.=1.396, 2.334), urban areas in general (OR=2.021, 95% C.I.=1.360, 3.003), and having urban address locations (OR=3.732, 95% C.I.=1.935, 7.196 entire study region), were significant risk factors for canine leptospirosis. Dogs regardless of age, sex and breed that live in urban areas are at higher risk of leptospirosis and vaccination should be considered.
Assuntos
Doenças do Cão/microbiologia , Leptospira/isolamento & purificação , Leptospirose/veterinária , Testes de Aglutinação/veterinária , Animais , Anticorpos Antibacterianos/sangue , DNA Bacteriano/química , DNA Bacteriano/genética , Doenças do Cão/epidemiologia , Cães , Feminino , Sistemas de Informação Geográfica , Kansas/epidemiologia , Leptospirose/epidemiologia , Leptospirose/microbiologia , Modelos Logísticos , Masculino , Nebraska/epidemiologia , Reação em Cadeia da Polimerase/veterinária , RNA Ribossômico 23S/química , RNA Ribossômico 23S/genética , Estudos Retrospectivos , População Rural , Estações do Ano , Estudos Soroepidemiológicos , População UrbanaRESUMO
In the context of intraparenchymal delivery of therapeutic agents into brain parenchyma for the purpose of treating serious brain diseases, we present the scientific and medical need for infusion from a single source to cover a large area of the cerebral cortex, which we refer to as 'surface-contoured distributions' (SCD). The designs of two devices suitable for obtaining such SCD's are described, and the results of preliminary experimental studies with prototypes of them are reported. The studies were done in ex vivo samples of mammalian brain tissues, and histological sections of the brains confirmed that we had covered the large surface area desired. Work to test that the infusate penetrates the thickness of the cortex remains for the future.