82 research outputs found
Landscape requirements of a primate population in a human-dominated environment
<p>Abstract</p> <p>Introduction</p> <p>As urban and rural land development become widespread features of the global landscape so an understanding of the landscape requirements of displaced and isolated wildlife species becomes increasingly important for conservation planning. In the Cape Peninsula, South Africa, rapid human population growth, and the associated urban and rural land transformation, threatens the sustainability of the local chacma baboon population. Here we analyse spatial data collected from nine of the 12 extant troops to determine their population-level landscape requirements. We use hurdle models to ascertain the key landscape features influencing baboon occurrence and abundance patterns on two hierarchical spatial scales.</p> <p>Results</p> <p>Both spatial scales produced similar results that were ecologically reliable and interpretable. The models indicated that baboons were more likely to occur, and be more abundant, at low altitudes, on steep slopes and in human-modified habitats. The combination of these landscape variables provides baboons with access to the best quality natural and anthropogenic food sources in close proximity to one another and suitable sleeping sites. Surface water did not emerge as an influential landscape feature presumably as the area is not water stressed.</p> <p>Conclusions</p> <p>The model results indicate that land development in the Cape Peninsula has pushed baboons into increasingly marginal natural habitat while simultaneously providing them with predictable and easily accessible food sources in human-modified habitats. The resultant spatial competition between humans and baboons explains the high levels of human-baboon conflict and further erosion of the remaining land fragments is predicted to exacerbate competition. This study demonstrates how the quantification of animal landscape requirements can provide a mechanism for identifying priority conservation areas at the human-wildlife interface.</p
PATHWAYS TO ADULTHOOD IN IRELAND: CAUSES AND CONSEQUENCES OF SUCCESS AND FAILURE IN TRANSITIONS AMONGST IRISH YOUTH. ESRI General Research Series Paper No. 161, December 1993
This is a study of two main transitions to adulthood amongst a large
sample of young Irish people who completed their second-level education
in 1981/82. It is based on final interviews carried out with them in late
1987 about their transitions to adulthood over tile preceding 5 to 6 years.
It studies their achievement of a sequence of interrelated adult statuses as
young people moved from dependence on their family of origin to
complete economic independence and the establishment of their own
households and their own new families
Survey of Infections Transmissible Between Baboons and Humans, Cape Town, South Africa
Baboons on South Africa’s Cape Peninsula come in frequent contact with humans. To determine potential health risks for both species, we screened 27 baboons from 5 troops for 10 infections. Most (56%) baboons had antibodies reactive or cross-reactive to human viruses. Spatial overlap between these species poses low but potential health risks
Feasibility study of the use of digital cameras for water quality monitoring in the coastal zone
The coastal zone is characteristically a turbid region of the sea with water clarity being an indicator of coastal dynamics. Turbidity affects water quality and aesthetic value. Previous investigations into water clarity in the Irish Sea have been conducted using imagery obtained from the Advanced Very High Resolution Radiometer (AVHRR). Good correlations were found between light reflectance and suspended sediment concentrations from this imagery. In order to investigate suspended sediment concentrations in the coastal zone, an area where satellite imagery does not ‘see well’, scientists from NUI, Galway, UW, Bangor and Compass Informatics Ltd. undertook a feasibility study to investigate the possibilities of using both in situ and airborne digital cameras to monitor water clarity in the coastal zone. The digital cameras capture visible spectrum imagery with assigned values for red, green and blue light, thus making a quantifiable measurement of the up-welling light of different colours in a similar manner to the UW, Bangor Ocean Colour Sensor used in this project and a previous INTERREG Project (White et al.; 2000). As suspended sediment concentrations were found to correlate well with in situ digital camera output values, it was anticipated that the camera would provide a successful method of monitoring Suspended Particulate Material (SPM) at fixed locations over a predetermined time period. In practice aerial imagery did not prove to be a feasible method for SPM monitoring in the type of dynamic coastal environment under this particular survey. A combination of sun glint, sky reflectance interference, strong tidal currents and time lapse between imagery capture and in situ data collection made the calibration of images very difficult. On the positive side, it was found that aerial imagery is ideally suited to observing coastal dynamical phenomena such as river plume development. These near shore dynamical processes cannot be monitored by satellite imagery and so aerial resolution and aircraft manoeuvrability are ideal for this type of coastal zone remote sensing.Funder: European Unio
The development and growth of the software industry in Ireland: an institutionalized relationship approach
peer-reviewedIreland's software industry emerged in the 1970s and 1980s due to significant international developments and, more importantly, the industrial policy approach adopted in Ireland. The attraction of software foreign direct investment during these decades was followed by the emergence of an internationally competitive Irish software sector. A multitude of factors combine to explain the trajectory of software in Ireland: from developments related to globalization and international trade, to policy makers' efforts to promote an industry where Ireland could forge a comparative advantage internationally. An analysis of industrial dynamics and institutionalized relationships (IRs) furthers our understanding of significant developments in the industry in terms of interactions between firms, government and other stakeholders. This paper makes a novel contribution by analysing Ireland's software industry within the IR framework. The IR approach we employ focuses on the finance IR, the purchase IR, the employment IR, and the commercial IR. The adoption of the IR framework approach is particularly insightful in the Irish case as it facilitates a multifaceted analysis of the complex relationships that have moulded the Irish software industry. Such an approach also facilitates a study of the policy implications and policy prescriptions that are pertinent to the software sector.ACCEPTEDpeer-reviewe
Prevalence of tumor BRCA1 and BRCA2 dysfunction in unselected patients with ovarian cancer
Objective
The therapeutic benefits of poly(ADP-ribose) polymerase inhibitors highlight the need to evaluate BRCA1/2 defects in tubal/ovarian cancer (OC). We sought to determine the pattern and disease characteristics associated with tumor BRCA1/2 mutations and BRCA1 methylation in women with OC.
Methods
We obtained 111 OC specimens from 2 university hospitals and assessed BRCA1/2 mutations and BRCA1 methylation in tumor DNA. The frequency and pattern of BRCA1/2 defects were examined. Associations between patient/disease characteristics and BRCA1/2 defects were ascertained (Fisher’s exact test). Platinum-free interval (PFI), progression-free survival (PFS), and overall survival (OS) based on the underlying BRCA1/2 defect were determined (Kaplan-Meier analysis [log-rank test]).
Results
We observed a BRCA1/2 dysfunction rate of 40% (28/70) in high-grade serous tubal/ovarian cancer (HGSC), including 14.3% BRCA1 methylation (n=10), 7.1% BRCA1 mutation (n=5), and 18.6% BRCA2 mutation (n=13). Defects in BRCA1/2 genes were associated with stage III/IV HGSC (BRCA1 methylation: P=0.005 [stage III/IV] and P=0.004 [HGSC]; BRCA1/2 mutation: P=0.03 [stage III/IV] and P<0.001 [HGSC]). Patients with BRCA1/2-mutated cancers showed improved OS (hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.43–0.99; P=0.045) and a trend toward improved PFI (HR, 0.48; 95% CI, 0.22–1.06; P=0.07) and PFS (HR, 0.72; 95% CI, 0.51–1.03; P=0.07). No survival differences were observed between BRCA1-methylated and BRCA1/2 wild-type non-BRCA1-methylated cancers.
Conclusion
We observed a high tumor BRCA1/2 dysfunction rate in HGSC with a unique predominance of BRCA2 over BRCA1 mutations. While BRCA1/2 mutations conferred survival benefits in OC, no such association was observed with BRCA1 methylation
Black-backed jackals (Canis mesomelas) from semi-arid rangelands in South Africa harbour Hepatozoon canis and a Theileria species but apparently not Babesia rossi
Despite the importance of disease as a wildlife management challenge in South Africa, baseline data on the epidemiology of pathogens occurring in free-ranging species has received little attention to date. Black-backed jackals (Canis mesomelas) are a wide-ranging, abundant carnivore with substantial economic importance due to their role in livestock depredation. They are known reservoirs hosts of Babesia rossi, a virulent pathogen in domestic dogs in sub-Saharan Africa. We investigated the prevalence and diversity of tick-borne pathogens (TPBs) including Babesia, Theileria, Hepatozoon, Ehrlichia and Anaplasma species, together with host-attached tick diversity, in a black-backed jackal population from the semi-arid Central Karoo, a small-livestock farming region in South Africa. Using reverse line blot hybridisation, we screened 43 blood samples and sequenced the 18S rRNA gene from positive samples to confirm and characterise pathogen identity using a phylogenetic framework. Hepatozoon canis, a ubiquitous pathogen of domestic and wild canids globally, was observed in 47% of jackals, while a Theileria sp. most similar to T. ovis, a piroplasm found in small livestock, was observed in 5% of jackals. No Babesia, Ehrlichia or Anaplasma species were identified, although a Sarcocystis sp. sequence was isolated from one jackal. Host-attached ticks (n = 20) comprised three species, Amblyomma marmoreum, Haemaphysalis elliptica/zumpti and Ixodes rubicundus, commonly known ticks in the region. In summary, prevalence of TBPs in black-backed jackals from this semi-arid rangeland region was lower than in jackal populations in more mesic regions. These jackals were apparently not infected with B. rossi. While this study is one of the first investigations into the epidemiology of TBPs infecting jackals and adds to the sparse literature, further studies which span landscape uses, climate conditions and seasonality are encouraged.Institute for Communities and Wildlife in Africa, University of Cape Town; Foundational Biodiversity Information Programme, National Research Foundation of South Africa; University of Cape Town Science Faculty Grant and National Research Foundation of South Africa; National Research Foundation Freestanding Masters bursary and Wilderness Wildlife Trust bursary.https://www.elsevier.com/locate/vprsr2022-03-31hj2022Centre for Veterinary Wildlife StudiesVeterinary Tropical Disease
CD10−/ALDH− cells are the sole cisplatin-resistant component of a novel ovarian cancer stem cell hierarchy
It is long established that tumour-initiating cancer stem cells (CSCs) possess chemoresistant properties. However, little is known of the mechanisms involved, particularly with respect to the organisation of CSCs as stem-progenitor-differentiated cell hierarchies. Here we aimed to elucidate the relationship between CSC hierarchies and chemoresistance in an ovarian cancer model. Using a single cell-based approach to CSC discovery and validation, we report a novel, four-component CSC hierarchy based around the markers cluster of differentiation 10 (CD10) and aldehyde dehydrogenase (ALDH). In a change to our understanding of CSC biology, resistance to chemotherapy drug cisplatin was found to be the sole property of CD10−/ALDH− CSCs, while all four CSC types were sensitive to chemotherapy drug paclitaxel. Cisplatin treatment quickly altered the hierarchy, resulting in a three-component hierarchy dominated by the cisplatin-resistant CD10−/ALDH− CSC. This organisation was found to be hard-wired in a long-term cisplatin-adapted model, where again CD10−/ALDH− CSCs were the sole cisplatin-resistant component, and all CSC types remained paclitaxel-sensitive. Molecular analysis indicated that cisplatin resistance is associated with inherent- and adaptive-specific drug efflux and DNA-damage repair mechanisms. Clinically, low CD10 expression was consistent with a specific set of ovarian cancer patient samples. Collectively, these data advance our understanding of the relationship between CSC hierarchies and chemoresistance, which was shown to be CSC- and drug-type specific, and facilitated by specific and synergistic inherent and adaptive mechanisms. Furthermore, our data indicate that primary stage targeting of CD10−/ALDH− CSCs in specific ovarian cancer patients in future may facilitate targeting of recurrent disease, before it ever develops
Perilous state of critically endangered Northwest African cheetah (Acinonyx jubatus hecki) across the Sudano‐Sahel
Northwest African cheetah populations have declined precipitously, with expert opinion estimating that <420 individuals persist across parts of Algeria, Benin, Burkina Faso, Chad, Niger and Mali. However, no reliable density estimates exist in the remaining subspecies strongholds throughout the Sudano‐Sahel Zone, including the W‐Arly‐Pendjari Complex and Greater Zakouma Ecosystem within the Bahr/Salamat landscape. Camera trap surveys were combined with spatially explicit capture–recapture methodologies in both regions to estimate the cheetah density and detectable demographic composition of these populations. Following 15 429 camera trap nights, we detected nine individuals during the dry season and four individuals during the wet season in Pendjari (2021), nine individuals (dry season; 2023) in Zakouma and none in Siniaka Minia. Cheetah densities were thus estimated at 0.17–0.24 and 0.37 cheetah per 100 km2 in Pendjari and Zakouma, respectively. While marginally higher than predicted, such low‐density estimates are concerning in the last remaining habitats harbouring this critically endangered subspecies. Considering the substantial contraction of regional cheetah distribution, we estimate an overall population size of 68 ± 29 individuals across the studied areas. These novel estimates are among the lowest formally determined densities throughout cheetah range in Africa, where a high frequency of people and livestock detected on camera traps highlight the ongoing risks to large carnivores in these protected areas. Subsequent management recommendations include implementation of the established regional conservation strategies that encompass the distributional range of these cheetah, continuous monitoring of populations, genetic analyses to inform management, curbing illegal trade and increasing international awareness around the plight of the subspecies
BRCA1 promoter methylation and clinical outcomes in ovarian cancer: an individual patient data meta-analysis
BACKGROUND
BRCA1 methylation has been associated with homologous recombination deficiency, a biomarker of platinum sensitivity. Studies evaluating BRCA1-methylated tubal/ovarian cancer (OC) do not consistently support improved survival following platinum chemotherapy. We examine the characteristics of BRCA1-methylated OC in a meta-analysis of individual participant data.
METHODS
2636 participants' data across 15 studies were analyzed. BRCA1-methylated tumors were defined according to their original study. Associations between BRCA1 methylation and clinico-pathological characteristics were evaluated. The effects of methylation on overall survival (OS) and progression-free survival (PFS) were examined using mixed-effects models. All statistical tests were two-sided.
RESULTS
430 (16.3%) tumors were BRCA1-methylated. BRCA1 methylation was associated with younger age and advanced-stage high-grade serous OC. There were no survival differences between BRCA1-methylated and non-BRCA1-methylated OC (median PFS = 20.0 vs 18.5 months, HR = 1.01, 95% CI = 0.87-1.16, P=0.98; median OS = 46.6 vs 48.0 months, HR = 1.02, 95% CI = 0.87-1.18, P=0.96). Where BRCA1/2 mutations were evaluated (n = 1248), BRCA1 methylation displayed no survival advantage over BRCA1/2 intact (BRCA1/2 wild type non-BRCA1-methylated) OC. Studies used different methods to define BRCA1 methylation. Where BRCA1 methylation was determined using methylation-specific PCR and gel electrophoresis (n = 834), it was associated with improved survival (PFS: HR = 0.80, 95% CI = 0.66-0.97, P=0.02; OS: HR = 0.80, 95% CI = 0.63-1.00, P=0.05) on mixed-effects modelling.
CONCLUSION
BRCA1-methylated OC displays similar clinico-pathological features to BRCA1-mutated OC, but is not associated with survival. Heterogeneity within BRCA1 methylation assays influences associations. Refining these assays may better identify cases with silenced BRCA1 function and improved patient outcomes
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