1,226 research outputs found
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Experimental crop growing in Jordan to develop methodology for the identification of ancient crop irrigation
No full textCrop irrigation has long been recognized as having been important for the evolution of social complexity in several parts of the world. Structural evidence for water management, as in the form of wells, ditches and dams, is often difficult to interpret and may be a poor indicator of past irrigation that may have had no need for such constructions. It would be of considerable value, therefore, to be able to infer past irrigation directly from archaeo-botanical remains, and especially the type of archaeo-botanical remains that are relatively abundant in the archaeological record, such as phytoliths. Building on the pioneering work of Rosen and Wiener (1994), this paper describes a crop-growing experiment designed to explore the impact of irrigation on the formation of phytoliths within cereals. If it can be shown that a systemic and consistent relationship exists between phytolith size, structure and the intensity of irrigation, and if various taphonomic and palaeoenvironmental processes can be controlled for, then the presence of past irrigation can feasibly be inferred from the phytoliths recovered from the archaeological record
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An 11 600 year-old communal structure from the Neolithic of southern Jordan
No full textThe authors present a new type of communal
and monumental structure from the earliest
Neolithic in western Asia. A complement to
the decorated stone pillars erected at G¨obekli
Tepe in the north, ‘Wadi Faynan 16 Structure
O75’ in the southern Levant is a ritualised
gathering place of a different kind. It serves to
define wider western Asia as an arena of social
experiment in the tenth millennium BC, one
in which community seems to take precedence
over economy
A retrospective review of Listeria monocytogenes infection at Tygerberg Children’s Hospital, Cape Town, South Africa, from 2006 to 2016 : is empirical ampicillin still indicated after the first month of life?
No full textCITATION: Oppel, K. B., Holgate, S. L. & Finlayson, H. 2018. A retrospective review of Listeria monocytogenes infection at Tygerberg Children’s Hospital, Cape Town, South Africa, from 2006 to 2016 : is empirical ampicillin still indicated after the first month of life? South African Medical Journal, 108(11):937-943, doi:10.7196/SAMJ.2018.v108i11.13212.The original publication is available at http://www.samj.org.zaBackground. Ampicillin to treat Listeria monocytogenes (LM) infection is empirically added to the treatment of infants (<3 months) with suspected sepsis or meningitis.
Objectives. In view of limited LM cases, the paucity of South African (SA) data and an ampicillin shortage, our objective was to describe the occurrence of LM infections at Tygerberg Hospital (TBH), Cape Town, with the aim of rationalising the paediatric antibiotic policy.
Methods. An 11-year (2006 - 2016) retrospective descriptive study of children (<13 years) from TBH and referral hospitals with a positive blood or cerebrospinal fluid (CSF) culture for LM was conducted.
Results. Of 26 children with positive cultures for LM, 23 (88.5%) were <3 months of age; all were <10 days old. Approximately half (56.5%, 13/23) were born at or referred to TBH. Presentation was on the day of delivery in 46.2% (6/13), 92.3% were admitted to the neonatal intensive care unit (NICU), and 61.5% (8/13) died. Neonates treated at peripheral hospitals were statistically more likely than those treated at TBH to have a CSF culture obtained (90.0% v. 30.8%; p=0.005), and had higher platelet counts (239 × 109/L v. 107 × 109/L; p=0.004), lower C-reactive protein levels (64 mg/L v. 137 mg/L; p=0.013) and a lower mortality rate (0% v. 61.5%; p=0.002). The incidence of LM at TBH was 0.04/1 000 live births and 2.3/1 000 NICU admissions.
Conclusions. As in other countries, the local neonatal LM incidence is low. Neonates present in the first week of life with severe disease and a high mortality rate. These data support a change in antibiotic policy, in keeping with international guidelines, limiting empirical ampicillin prescription to infants <1 month of age.http://www.samj.org.za/index.php/samj/article/view/12460Publisher's versio
Investigation of FEAR and MEN pathway homologs in multinucleate cells
No full textThe cell cycle is a sequence of events enabling a cell to replicate and proliferate. Common landmark events in most eukaryotic cell cycles are duplication of the DNA, mitosis, and cell separation. The cell cycle lays the basis for development in multicellular organisms, and is of course important for cell or tissue renewal. Disregulation of the cell cycle can lead to uncontrolled growth and tumor formation.
Mitosis, or nuclear division, is tightly regulated to ensure proper segregation of nuclei to daughter cells. In budding yeast (S. cerevisiae), the timing of mitosis is coupled to cytokinesis by the action of the FEAR and MEN regulatory networks, which mediate exit from mitosis by activation of the phosphatase ScCdc14.
In this thesis, we investigate the function of homologs of these pathways in the filamentous fungus, Ashbya gossypii. This organism provides a unique cellular setting to study these matters, as it is a close relative of S.cerevisiae and shares most of the molecular machinery. However within its multinucleate hyphae, mitosis is uncoupled from cytokinesis, and cytokinesis is not followed by cell separation, thus leading to compartments containing 8-10 nuclei, separated by septa. We look into how exit from mitosis is affected in such a cellular environment where nuclei are free to divide without the spatial and temporal constraints as described in budding yeast, where each mitosis is followed by cytokinesis and cell separation.
First we study the core component of exit from mitosis signalling. We examinethe phosphatase AgCdc14 and discover that its regulation is very similar to S. cerevisiae, with the phosphatase being sequestered within the nucleolus throughout interphase, and released during anaphase. Furthermore, we find it to be an essential component in nuclear cycle progression in A. gossypii, with nuclei in null mutants failing to undergo mitosis.
We then look at MEN homologs in A. gossypii and present evidence that the kinase cascade function of the pathway is likely conserved. We however show MEN homologs to be non-essential and play no role in AgCdc14 regulation. On the other hand, we detect sporulation deficiencies in our mutants, which we could attribute to septation defects. More interestingly, we observe a partial mitotic arrest in MEN deficient cells. MEN homologs thus seem to have diverged from the primary role of their counter-parts in budding yeast.
The final chapter deals with homologs of the FEAR pathway. It had been previously suggested that, in primitive cells, the task of Cdc14 phosphatase regulation may be solely bestowed upon this network of genes. We find this to hold true for A. gossypii, where we report severe mitotic defects upon deletion of FEAR homologs, and in particular, disruption of control over AgCdc14 release.
We interpret the results as evidence for a simpler system regulating exit from mitosis in A. gossypii and lay out potential implications for the more complex system in S. cerevisiae
Fig. 2 in Ventral dermatitis in rowi (Apteryx rowi) due to cutaneous larval migrans
No full textFig. 2. Photomicrographs of skin biopsies taken from the ventral abdomen of rowi (Apteryx rowi) showing larval nematodes in tangential section (A) and cross section (B). Perivascular inflammation is evident in the dermis in both images.Published as part of <i>Gartrell, B.D., Argilla, L., Finlayson, S., Gedye, K., Argandona, A.K. Gonzalez, Graham, I., Howe, L., Hunter, S., Lenting, B., Makan, T., McInnes, K., Michael, S., Morgan, K.J., Scott, I., Sijbranda, D., Zyl, N. van & Ward, J.M., 2015, Ventral dermatitis in rowi (Apteryx rowi) due to cutaneous larval migrans, pp. 1-10 in International Journal for Parasitology: Parasites and Wildlife 4 (1)</i> on page 5, DOI: 10.1016/j.ijppaw.2014.11.001, <a href="http://zenodo.org/record/10668316">http://zenodo.org/record/10668316</a>
Results from the 2001 Excavations at Dhra', Jordan: Chipped Stone Technology, Typology, and Intra-Assemblage Variability
No full textThis paper provides an overview of the chipped stone assemblage recovered in the six week 2001 field season at the PPNA settlement of Dhra ' located in south Jordan. The Dhra ' site excavations produced a lithic assemblage that in numbers is comparable, or even surpasses, that of Netiv Hagdud. Lithic analysis is ongoing, and this paper represents a detailed preliminary discussion of the technology, typology, and distributional patterns yielded by the Dhra ' lithic assemblage. Some initial comparisons are made between these results and other PPNA lithic assemblages recovered in the southern Levant.Présentation de l'industrie lithique recueillie en 2001 lors d'une campagne de fouilles de six semaines sur le site PPNA de Dhra ' au sud de la Jordanie. Les fouilles sur ce site ont produit un assemblage lithique qui est comparable ou même surpasse par sa qualité celui de Netiv Hagdud. L 'analyse étant en cours nous présentons ici une discussion détaillée de la technologie, de la typologie et de la répartition dans le site de l'assemblage lithique. Quelques premières comparaisons peuvent être faites entre nos résultats et ceux obtenus sur d'autres sites PPNA du Sud-Levant.Goodale Nathan, Kuijt Ian, Finlayson Bill. Results from the 2001 Excavations at Dhra', Jordan: Chipped Stone Technology, Typology, and Intra-Assemblage Variability. In: Paléorient, 2002, vol. 28, n°1. pp. 125-140
Measuring food intake, hunger, satiety and satiation in the laboratory
No full textThis handbook is a comprehensive collection of measures and assessment tools intended for use by researchers and clinicians that work with people with problem eating behaviors, obese clients, and the associated psychological issues that underlie these problems. It is a reference for researchers who specialize in obesity research and individuals that specialize in working with clients with problem eating behaviors and how to measure and assess their attitudes, beliefs and behaviors with regard to food. It is much broader than eating disorders as it deals with obesity (an area that has reached epidemic proportions in the US) and problem eating behaviors. Its collection is truly unique as no other volume offers such a comprehensive collection all in one place dealing with and focusing on assessments and measures related to eating behaviours. The assessment tools included in this volume include:\ud
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- General Personality Assessment and psychopathology of persons with eating and weight related concerns \ud
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- Measures of quality of life assessments \ud
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- Methods for measuring attitudes and beliefs about obese people \ud
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- Assessment of Body Image \ud
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- Measures of Restrained Eating \ud
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- Measures of Physical Activity \ud
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- Measuring Food Intake \ud
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- Binge Eating and Purging \ud
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- Assessment of Eating and Weight related problems with Children \ud
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- Identification of Psychological Problems of patients with eating disorders. \u
Big bees do a better job : intraspecific size variation influences pollination effectiveness
No full textFunding: School of Biology, University of St AndrewsBumblebees (Bombus spp.) are efficient pollinators of many flowering plants, yet the pollen deposition performance of individual bees has not been investigated. Worker bumblebees exhibit large intraspecific and intra-nest size variation, in contrast with other eusocial bees; and their size influences collection and deposition of pollen grains. Laboratory studies with B. terrestris workers and Vinca minor flowers showed that pollen grains deposited on stigmas in single visits (SVD) were significantly positively related to bee size; larger bees deposited more grains, while the smallest individuals, with proportionally shorter tongues, were unable to collect or deposit pollen in these flowers. Individuals did not increase their pollen deposition over time, so handling experience does not influence SVD in Vinca minor. Field studies using Geranium sanguineum and Echium vulgare, and multiple visiting species, confirmed that individual size affects SVD. All bumblebee species showed size effects, though even the smallest individuals did deposit pollen, whereas there was no detectable effect with Apis with its limited size variation. Two abundant hoverfly species also showed size effects, particularly when feeding for nectar. Mean size of foragers also varied diurnally, with larger individuals active earlier and later, so that pollination effectiveness varies through a day; flowers routinely pollinated by bees may best be served by early morning dehiscence and visits from larger individuals. Thus, while there are well-documented species-level variations in pollination effectiveness, the fine-scale individual differences between foragers should also be taken into account when assessing the reproductive outputs of biotically-pollinated plants.Peer reviewe
Accurate Quantification of Anthocyanin in Red Flesh Apples Using Digital Photography and Image Analysis
No full textRed fleshed apples (Malus × domestica Borkh.) differ in colour intensity between cultivars, seasons and sites. The objective of this study was to develop a procedure for predicting anthocyanin content from digital images of flesh discs. Flesh cylinders of uniform colour were excised, scanned and their colours determined in the R, G and B and the L*a*b* colour spaces. Anthocyanin content was also quantified chemically. A calibration line was constructed to predict anthocyanin content of flesh discs of varying colour from a scan or a photograph in the studio or outdoors. Anthocyanin concentration was linearly related to the logarithms of G, B and L*. From these relationships, the anthocyanin content of a flesh disc was predicted, pixel by pixel. Colour corrections were applied using a reference colour chart included in all images. The Finlayson algorithm was most effective for correcting the G parameter obtained by a flatbed scanner. For variable imaging methods (scanning or photography), the Vandermonde algorithm for correcting the L* parameter and the Finlayson algorithm for correcting the G parameter were most effective in predicting anthocyanin content. The procedure allows accurate prediction of anthocyanin content of red fleshed apples from simple colour scans or photographs
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