RESUMEN
Conservationists often advocate for landscape approaches to wildlife management while others argue for physical separation between protected species and human communities, but direct empirical comparisons of these alternatives are scarce. We relate African lion population densities and population trends to contrasting management practices across 42 sites in 11 countries. Lion populations in fenced reserves are significantly closer to their estimated carrying capacities than unfenced populations. Whereas fenced reserves can maintain lions at 80% of their potential densities on annual management budgets of $500 km(-2) , unfenced populations require budgets in excess of $2000 km(-2) to attain half their potential densities. Lions in fenced reserves are primarily limited by density dependence, but lions in unfenced reserves are highly sensitive to human population densities in surrounding communities, and unfenced populations are frequently subjected to density-independent factors. Nearly half the unfenced lion populations may decline to near extinction over the next 20-40 years.
Asunto(s)
Carnívoros , Conservación de los Recursos Naturales/métodos , Leones , Densidad de Población , Animales , Conservación de los Recursos Naturales/economía , Ghana , Humanos , Namibia , Dinámica Poblacional , Sector Privado , SudáfricaRESUMEN
The objectives of this study were to investigate the effects of prolonged storage of cauda epididymides at 4 degrees C on spermatozoa, and to determine the practicality of utilising epididymal sperm, harvested from testes collected during routine culling of game animals, in assisted reproductive technologies. Testes from eland (Taurotragus oryx) were collected and epididymides removed and maintained at 4 degrees C. Sperm motility, viability, morphology and membrane integrity were examined at 12 h intervals for 108 h. Sperm motility and viability were significantly lower at the end of the experiment than at the start (P < 0.05) and there was individual variation in the rate at which motility and viability declined. The total number of normal sperm decreased significantly with prolonged storage at 4 degrees C. Midpiece defects were the most common and head and tail abnormalities were rare. A significant decrease in acrosomal and nuclear membrane integrity was observed with prolonged cold storage but there was no significant change in cell membrane integrity. However, about 30% of epididymal sperm survived for 3 days at 4 degrees C and more than 10% survived for 4 days, and it should be possible to use sperm from culled animals in some assisted reproductive technologies.
Asunto(s)
Biodiversidad , Frío , Epidídimo/fisiología , Preservación de Órganos/veterinaria , Rumiantes , Espermatozoides/fisiología , Acrosoma/ultraestructura , Animales , Membrana Celular/ultraestructura , Supervivencia Celular , Epidídimo/citología , Masculino , Preservación de Semen/veterinaria , Motilidad Espermática , Espermatozoides/anomalías , Espermatozoides/ultraestructuraRESUMEN
Normal human skin is remarkably resistant to infection from the large numbers of microorganisms that routinely colonize its surface. In addition to the role of skin as a mechanical barrier, it has long been recognized that skin and other epithelia can produce a range of anti-microbial chemicals that play an important part in eliminating potential cutaneous pathogens. Anti-microbial peptides are an important evolutionarily conserved innate host defense mechanism in many organisms. Human beta defensin-1 and -2 are cysteine-rich, cationic, low molecular weight anti-microbial peptides that have recently been shown to be expressed in epithelial tissues. In this study, we describe the characterization of human beta defensin-1 and -2 mRNA and peptide expression in normal human skin. Using reverse transcription-polymerase chain reaction we demonstrate that human beta defensin-1 is consistently expressed in skin samples from various body sites. Human beta defensin-2 demonstrates expression that is more variable and is more readily detectable in facial skin and foreskin compared with skin from abdomen and breast. In situ hybridization localizes the human beta defensin-1 and -2 transcripts to keratinocytes within interfollicular skin. Using specific antibodies, we have shown that human beta defensin-1 and -2 peptides are localized to the Malpighian layer of the epidermis and/or stratum corneum and that there are interindividual and site-specific differences in intensity of immunostaining and the pattern of peptide localization. The localization of human beta defensins to the outer layer of the skin is consistent with the hypothesis that human beta defensins play an essential part in cutaneous innate immunity.
Asunto(s)
Células Epidérmicas , Queratinocitos/fisiología , beta-Defensinas/genética , Células 3T3 , Animales , Anticuerpos , Expresión Génica/fisiología , Humanos , Inmunidad Innata/fisiología , Queratinocitos/citología , Mesodermo/citología , Ratones , ARN Mensajero/análisis , beta-Defensinas/análisis , beta-Defensinas/inmunologíaRESUMEN
OBJECTIVE: To determine changes in the cervical screening service since the introduction of the new general practitioner contract on 1 April 1990. DESIGN: Analysis of computerised records of cervical screening both before and after introduction of the new contract. SETTING: General practices in Perth and Kinross Unit, Tayside. PATIENTS: A total of 30,071 women aged 21-60 on 26 general practitioner partnership lists. MAIN OUTCOME MEASURES: Percentage average of target population for cervical screening in each practice for first three quarters on introduction of the contract. RESULTS: Perth and Kinross Unit completed a computerised cervical screening call programme in July 1989, which produced an increase from 71% to 78% in the mean percentage of women aged 20-60 who had had cervical smear tests within 5.5 years. Six months after the introduction of the new general practitioner contract the mean population coverage was increased to 85% in women aged 21-60 and only four practices had not attained the 80% upper target compared with 10 on 1 April 1990. Detailed examination of randomly selected practices immediately before the new contract was introduced showed an average artificial list inflation of 4.3% in health board records when compared with practice records, a hysterectomy rate of 6.2%, and an additional 3% of women who were considered to be ineligible for smear testing due to putative virginity or illness or infirmity, or both. There was a considerable shift away from use of well woman clinics (2.7% of smears in 1990 compared with 5.6% in 1988) for taking cervical smears, potentially threatening the long term viability of the clinics. CONCLUSION: The introduction of the new contract for general practitioners has brought about a further sustained increase in population coverage for cervical screening in a small Scottish unit with a stable population, well motivated general practitioners, and a fully integrated computerised call and recall system based on the community health index. To optimise the screening service revision of the targets levels is necessary.
Asunto(s)
Medicina Familiar y Comunitaria/tendencias , Tamizaje Masivo/estadística & datos numéricos , Neoplasias del Cuello Uterino/prevención & control , Frotis Vaginal/estadística & datos numéricos , Adulto , Servicios Contratados , Femenino , Humanos , Persona de Mediana Edad , Aceptación de la Atención de Salud/estadística & datos numéricos , EscociaRESUMEN
For many years Tayside has benefited from a successful opportunistic cytology screening programme. In recent years, however, the decrease in mortality due to cervical cancer has levelled off, with most cases of severe disease arising in women who have not been screened. In view of this the health board developed a new computer system for call and recall based on the community health index. This facility allowed the unscreened population to be identified and located on an individual general practice basis. The findings of the call programme in the 3136 women aged 50-60 were studied. The 29 practices in Perth and Kinross participated in the scheme. Before the call started 4287 out of 7423 (58%) women had been screened, and after the call programme this had risen to 5109 (69%). Moreover, a further 1158 (15%) women were identified who had a valid reason for exclusion from the programme. This meant that 6267 (84%) women of the study population were accounted for by the system. The call programme in Tayside will be completed in 1989 and will include all women aged 20-60.
Asunto(s)
Computadores , Tamizaje Masivo/métodos , Cooperación del Paciente/estadística & datos numéricos , Neoplasias del Cuello Uterino/prevención & control , Frotis Vaginal , Estudios de Evaluación como Asunto , Medicina Familiar y Comunitaria , Femenino , Humanos , Tamizaje Masivo/estadística & datos numéricos , Persona de Mediana Edad , Escocia , Factores de TiempoRESUMEN
In this paper a computer system for cervical screening call and recall based on the Community Health Index (CHI) population data-base is described. It allows the unscreened population to be identified and located on an individual general practice basis. The results of the call programme on 9517 women aged 20-60 years listed on the CHI and with no record of a cervical smear is described. There was a 24% smear uptake in the call programme which meant that after the call programme the total population cover had risen from 71% to 78%. In addition, if women with a valid reason are excluded, and the data-base corrected for women no longer in the area, the true cover rises to 88%. An analysis of the percentage cover in each GP practice is described with the implications for implementation of screening targets for primary care.