1,500 research outputs found
First evidence of industrial fly-ash in an Antarctic ice core
Spheroidal carbonaceous particles (SCPs) are a component of fly-ash, the particulate by-product of industrial high temperature combustion of fuel-oil and coal-series fuels. We provide the first evidence that these indelible markers of industrialisation have been deposited in Antarctic ice, thousands of kilometres from any potential source. The earliest observed particle was deposited in an ice layer from 1936 CE. While depositional fluxes are low, chemical analysis of individual SCPs indicates a coal combustion origin
Respon penduduk terhadap penganjuran acara : analisis pelancongan acara melalui media sosial Perbadanan Putrajaya
Pelancongan acara menjadi sub pelancongan yang popular masa kini dan memberi pulangan modal yang besar
dalam meningkatkan ekonomi sesebuah destinasi. Kajian ini bertujuan untuk menilai respon penduduk setempat
terhadap penganjuran acara di Pusat Pentadbiran Putrajaya. Satu analisis kandungan terhadap respon penduduk
selepas penganjuran acara di dalam laman sosial (Facebook) Perbadanan Putrajaya telah diilakukan. Hasil kajian
mendapati penduduk setempat memberikan respon yang negatif terhadap acara-acara yang di anjurkan di Putrajaya,
Hanya segelintir sahaja daripada mereka yang memberikan respon positif. Justeru, pihak Perbadanan Putrajaya perlu
meningkatkan promosi pelancongan acara yang dapat menarik minat dan penyertaan para penduduk pada masa akan
datang
Improvements in the fossil record may largely resolve current conflicts between morphological and molecular estimates of mammal phylogeny
Phylogenies of mammals based on morphological data continue to show several major areas of conflict with the current consensus view of their relationships, which is based largely on molecular data. This raises doubts as to whether current morphological character sets are able to accurately resolve mammal relationships. We tested this under a hypothetical ‘best case scenario’ by using ancestral state reconstruction (under both maximum parsimony and maximum likelihood) to infer the morphologies of fossil ancestors for all clades present in a recent comprehensive DNA sequencebased phylogeny of mammals, and then seeing what effect the subsequent inclusion of these predicted ancestors had on unconstrained phylogenetic analyses of morphological data. We found that this resulted in topologies that are highly congruent with the current consensus phylogeny, at least when the predicted ancestors are assumed to be well preserved and densely sampled. Most strikingly, several analyses recovered the monophyly of clades that have never been found in previous morphology-only studies, such as Afrotheria and Laurasiatheria. Our results suggest that, at least in principle, improvements in the fossil record—specifically the discovery of fossil taxa that preserve the ancestral or near-ancestral morphologies of the nodes in the current consensus—may be sufficient to largely reconcile morphological and molecular estimates of mammal phylogeny, even using current morphological character set
Mycobacterium tuberculosis PPD-induced immune biomarkers measurable in vitro following BCG vaccination of UK adolescents by multiplex bead array and intracellular cytokine staining
BACKGROUND: The vaccine efficacy reported following Mycobacterium bovis Bacillus Calmette Guerin (BCG) administration to UK adolescents is 77% and defining the cellular immune response in this group can inform us as to the nature of effective immunity against tuberculosis. The aim of this study was to identify which cytokines and lymphocyte populations characterise the peripheral blood cellular immune response following BCG vaccination. RESULTS: Diluted blood from before and after vaccination was stimulated with Mycobacterium tuberculosis purified protein derivative for 6 days, after which soluble biomarkers in supernatants were assayed by multiplex bead array. Ten out of twenty biomarkers measured were significantly increased (p < 0.0025) 1 month after BCG vaccination when compared to paired samples (n = 12) taken prior to vaccination (IFNgamma, TNFalpha, IL-1alpha, IL-2, IL-6, IL-10, IL-17, GM-CSF, MIP1alpha, IP-10). All of these remained detectable by multiplex bead array in samples taken 12 months after BCG vaccination of a partially overlapping adolescent group (n = 12). Intracellular cytokine staining after 24 hour Mycobacterium tuberculosis purified protein derivative stimulation of PBMC samples from the 12 month group revealed that IFNgamma expression was detectable in CD4 and CD8 T-cells and natural killer cells. Polyfunctional flow cytometry analysis demonstrated that cells expressing IFNgamma alone formed the majority in each subpopulation of cells. Only in CD4 T-cells and NK cells were there a notable proportion of responding cells of a different phenotype and these were single positive, TNFalpha producers. No significant expression of the cytokines IL-2, IL-17 or IL-10 was seen in any population of cells. CONCLUSIONS: The broad array of biomarker responses detected by multiplex bead array suggests that BCG vaccination is capable, in this setting, of inducing a complex immune phenotype. Although polyfunctional T-cells have been proposed to play a role in protective immunity, they were not present in vaccinated adolescents who, based on earlier epidemiological studies, should have developed protection against pulmonary tuberculosis. This may be due to the later sampling time point available for testing or on the kinetics of the assays used
Peri-Abortion Contraceptive Choices of Migrant Chinese Women: A Retrospective Review of Medical Records
BACKGROUND: Migrant Asian women reportedly have low levels of contraceptive use and high rates of abortion in New Zealand. Chinese make up the largest proportion of migrant Asian in New Zealand. This study aimed to describe the contraceptive choices of Chinese women seeking abortion; to examine method choice in relation to demographic characteristics (including length of stay) and to determine whether Chinese women were over-represented among abortion clinic attendees. METHODS: Retrospective review of medical records at a public hospital abortion clinic involving 305 Chinese women. Previously collected data for European (n = 277) and Maori women (n = 128) were used for comparative analyses. Regression analyses explored correlates of contraceptive method choice. Population census data were used to calculate rates of clinic attendance across ethnic groups. RESULTS: Chinese women were not over-represented among clinic attendees, and had similar rates of contraceptive non-use pre-abortion as women in comparison groups. Use of the oral contraceptive pill by Chinese was lower pre-abortion than for other ethnic groups, but choice of this method post-abortion was similar for Chinese (46.9%, 95% CI 41-52.7) and European women (43.7%, 95% CI 37.8-49.7). Post-abortion choice of an intrauterine device did not differ significantly between Chinese (28.9%, 95% CI 23.8-34.3) and Maori women (37%, 95% CI 28.4-45.7), but was higher than uptake of this method by European women (21.7%, 95% CI 17-27.0). Age, parity and previous abortion were significant predictors of post-abortion method choice by Chinese women (p<0.05). CONCLUSIONS: Following contraceptive counseling at the clinic, Chinese women chose more effective contraceptive methods for use post-abortion than they had used previously. As the population of migrant Chinese in New Zealand continues to increase, strategies are urgently needed to provide new arrivals with appropriate information and advice about contraception and where to access it, so women can be better prepared to avoid unplanned pregnancy
Dilema perumahan penduduk tempatan Bukit Fraser dalam arus pembangunan ekopelancongan (Ecotourism development and the housing dilemma of the local community: the case of Fraser’s Hill)
Konsep perumahan bukan hanya setakat menyediakan tempat berteduh, tetapi mencakupi komponen
prasarana/infrastruktur, kemudahan awam dan perkhidmatan sosial, alam persekitaran dan komuniti. Setiap
komponen yang tersenarai memerlukan perancangan penyediaan dan pengagihan supaya kawasan perumahan
memenuhi kehendak penduduknya kerana ia melibatkan perubahan dalam masyarakat dan sistem sosial
daripada keadaan yang dianggap tidak memuaskan kepada keadaan yang lebih baik akibat beberapa kriteria
yang seragam dalam lingkungan yang dibentuk. Tujuan kajian ini ialah memantau kesejahteraan penduduk
tempatan dalam aspek perumahan di Bukit Fraser yang merupakan destinasi eko pelancongan tersohor di negeri
Pahang. Kajian mendapati saiz rumah, reka bentuk rumah, susunatur perumahan, rekabentuk jalanraya, bilangan
lampu jalan, kemudahan tempat beribadah, kemudahan tempat pembuangan sampah sarap berpusat dan
berhampiran kawasan tempat tinggal, dan kemudahan bagi penduduk lama sebagai faktor-faktor perumahan
yang mempengaruhi kualiti kesejahteraan hidup penghuni di Bukit Fraser
Cellular adaptations to hypoxia and acidosis during somatic evolution of breast cancer
Conceptual models of carcinogenesis typically consist of an evolutionary sequence of heritable changes in genes controlling proliferation, apoptosis, and senescence. We propose that these steps are necessary but not sufficient to produce invasive breast cancer because intraductal tumour growth is also constrained by hypoxia and acidosis that develop as cells proliferate into the lumen and away from the underlying vessels. This requires evolution of glycolytic and acid-resistant phenotypes that, we hypothesise, is critical for emergence of invasive cancer. Mathematical models demonstrate severe hypoxia and acidosis in regions of intraductal tumours more than 100 m from the basement membrane. Subsequent evolution of glycolytic and acid-resistant phenotypes leads to invasive proliferation. Multicellular spheroids recapitulating ductal carcinoma in situ (DCIS) microenvironmental conditions demonstrate upregulated glucose transporter 1 (GLUT1) as adaptation to hypoxia followed by growth into normoxic regions in qualitative agreement with model predictions. Clinical specimens of DCIS exhibit periluminal distribution of GLUT-1 and Na+/H+ exchanger (NHE) indicating transcriptional activation by hypoxia and clusters of the same phenotype in the peripheral, presumably normoxic regions similar to the pattern predicted by the models and observed in spheroids. Upregulated GLUT-1 and NHE-1 were observed in microinvasive foci and adjacent intraductal cells. Adaptation to hypoxia and acidosis may represent key events in transition from in situ to invasive cancer
GLOWORM-PARA: a flexible framework to simulate the population dynamics of the parasitic phase of gastrointestinal nematodes infecting grazing livestock
Gastrointestinal nematodes are a significant threat to the economic and environmental sustainability of keeping livestock, as adequate control becomes increasingly difficult due to the development of anthelmintic resistance in some systems and climate-driven changes to infection dynamics. To mitigate any negative impacts of climate on gastrointestinal nematode epidemiology and slow anthelmintic resistance development, there is a need to develop effective, targeted control strategies that minimise the unnecessary use of anthelmintic drugs and incorporate alternative strategies such as vaccination and evasive grazing. However, the impacts climate and gastrointestinal nematode epidemiology may have on the optimal control strategy are generally not considered, due to lack of available evidence to drive recommendations. Parasite transmission models can support control strategy evaluation to target field trials, thus reducing the resources and lead-time required to develop evidence-based control recommendations incorporating climate stochasticity. Gastrointestinal nematode population dynamics arising from natural infections have been difficult to replicate and model applications have often focussed on the free-living stages. A flexible framework is presented for the parasitic phase of gastrointestinal nematodes, GLOWORM-PARA, which complements an existing model of the free-living stages, GLOWORM-FL. Longitudinal parasitological data for two species that are of major economic importance in cattle, Ostertagia ostertagi and Cooperia oncophora, were obtained from seven cattle farms in Belgium for model validation. The framework replicated the observed seasonal dynamics of infection in cattle on these farms and overall, there was no evidence of systematic under- or over-prediction of faecal egg counts. However, the model under-predicted the faecal egg counts observed on one farm with very young calves, highlighting potential areas of uncertainty that may need further investigation if the model is to be applied to young livestock. The model could be used to drive further research into alternative parasite control strategies such as vaccine development and novel treatment approaches, and to understand gastrointestinal nematode epidemiology under changing climate and host management
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