2,993 research outputs found
Studies in the osteology of the human foetus and infant: being an investigation into the length of the long bones of the skeleton at different ages, and into the special characters which they present
The investigation which has led to the results herein
described was commenced with a view to determine
merely the relative lengths of the long bones of the
human foetus at different stages of "its development.
For this purpose a considerable number of specimens
was collected together and measurements were taken,
but, while examining the bones my attention was
struck by certain constant peculiarities in the
shape of several of the bones, especially about the
articular ends of these of the lower extremity,
features which are not present, as a rule, in the
European adult but some of which are known to be
present in the skeletons of the lower races of mankind, or of prehistoric man, and in apes.As a summary the following is a statement of my
conclusions:-(1) At an early age the proportionate length of
the bones is very different from what it is
in the adult.(2) As development proceeds the adult proportions
are gradually assumed, but even at birth the
general tendency of the proportions as shown
by the indices approximates towards that found
in the apes.(3) The relative lengths are never similar to what
is found in any one race of mankind; resembling
one race- e.g., the Esquimaux- in one respect
but differing from it in another(4) The configuration of the skeleton of the lowei
limb presents some striking divergences from
that of the adult and resembles in some respecjts
the skeleton of the apes and of some prehis¬
toric people.(5) This peculiar configuration is not adapted to
the erect attitude of the adult and becomes
modified even before physical forces can come
into play.(6) These differences may be ascribed either to a
mechanical cause- intra-uterine attitude- or
to a morphological cause. Further information
is still required before this question can
be settled
Structural studies of putative general stress and related proteins from Deinococcus radiodurans
This study describes the cloning, expression, purification, biophysical characterisation and crystallisation of DR_1146; a putative general stress protein from the extremophilic bacterium Deinococcus radiodurans (R1).
The extraordinary ability of D. radiodurans to resist mutation or apoptosis on exposure to high does of ionising radiation has formed the basis of a structural genomics project underway at the European Synchrotron Radiation Facility (ESRF), Grenoble, France. The work presented in this study forms part of the ESRF’s D. radiodurans initiative, and was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and the ESRF as an Industrial Cooperative Award in Science and Engineering (CASE) PhD studentship. A period of one-year was spent on secondment at the ESRF, working within the Macromolecular Crystallography Group.
Several constructs of the dr_1146 gene have been successfully overexpressed in E. coli cells to give high yields of target protein. Purification by immobilised metal affinity chromatography (IMAC) was facilitated by the incorporation of a 6xHis tag and supplemented by a final gel filtration step. Although high purity levels were achieved, imaging by SDS-PAGE analysis identified that DR_1146 was susceptible to stringent proteolysis. It is thought that initial crystallisation trials were unsuccessful due to inhomogeneity of the sample caused by reported degradation of the target protein.
Biophysical characterisation of DR_1146 by isothermal titration calorimetry (ITC) and fluorescence spectroscopy (FS) identified a moderate affinity of 4-11 μM for the flavin molecules, riboflavin, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). Differential scanning calorimetry (DSC) and circular dichroism (CD) experiments demonstrated an increase in chemical and thermal stability of the protein on binding to the flavin molecule, FMN.
Analytical ultracentrifugation (AUC) and Nuclear magnetic resonance (NMR) spectroscopy were employed to investigate the solution behaviour of DR_1146 in the presence of FMN. AUC results uncovered a monomer-dimer equilibrium; with DR_1146 self-associating to form a dimer at a concentration of 7.67 μM. NMR spectroscopy depicted that global changes occur within the structure of DR_1146 on binding to FMN. The high quality of spectra obtained showed potential for 3-D structure determination by NMR if ordered crystals could not be obtained for X-ray diffraction. Interestingly, analysis of NMR spectra proved to be integral to identifying a homogenous sample for successful crystallisation of DR_1146. By monitoring chemical shifts it was possible to determine the time needed for degradation of DR_1146 to cease, and the amount of FMN needed to ensure saturation of binding sites. From this particular sample, a stable 28 kDa fragment was isolated by gel filtration. Automated sitting-drop vapour-diffusion experiments resulted in the growth of yellow DR_1146-FMN crystals for which, although poor in quality, X-ray diffraction was obtained. Overall this study reflects the importance and advantage of incorporating information gained from biophysical characterisation into the strategies employed for successful protein crystallisation.
The characterisation of DR_1146 as a flavoprotein points towards a possible role in electron transfer due to the extensive redox capacity of flavin. This could implicate the protein in the production of damaging reactive oxygen species (ROS) as a result of irradiation, contributing to oxidative stress levels. Alternatively, if DR_1146 is identified as a FMN-binding pyridoxine 5'-phosphate oxidase (PNPOx) enzyme, as sequence homology suggests, it could play a role in detoxification and stress response through production of pyridoxal 5'-phosphate (PLP), a known scavenger of ROS. Only further characterisation and elucidation of a 3-D structure would confirm or dispel these functional hypotheses and ultimately provide a greater understanding of how D. radiodurans is able to deal with such oxidising conditions.
Simultaneously, experiments were carried out on other soluble and membrane protein targets from D. radiodurans and their corresponding homologues from Streptococcus pneumoniae (TIGR4). The aim of comparable studies was to identify key structural or functional differences between the two Gram-positive bacterial strains. Identification of features unique to D. radiodurans, but unconserved in S. pneumoniae, could contribute to further understanding of bacterial radioresistance.
SP_1651 is a thiol peroxidase which forms part of the Mn-ABC transport system in S. pneumonia. Its homologue from D. radiodurans, DR_2242 is a putative thiol-specific antioxidant protein, the structure of which has been solved by Dr. Dave Hall as part of the ESRF’s structural genomics project (unpublished). The aim of this part of the project was to elucidate the structure of SP_1651 so that a comparison with DR_2242 could be made.
The sp_1651 gene (psaD) was successfully expressed and purified to homogeneity by IMAC and gel filtration. After the proteolytic removal of a 6xHis tag, the purified protein was crystallised by sitting-drop vapour-diffusion. Preliminary diffraction with a resolution limit of 3.2 Ã… was obtained, however data showed high mosaic spread. Unfortunately, attempts to reproduce initial crystals failed and hence, structural comparisons with DR_2242 could not be made.
DR_0463 is a 108 kDa maltooligosyltrehalose synthase (MTSase) which has been shown to catalyse the breakdown of maltooligosaccharide (or starch) into the disaccharide, trehalose. The full length gene was expressed in BL21(DE3)pLysS cells, producing large yields of insoluble target protein. DR_0463 was solubilised with 8 M Urea and then purified by IMAC in the presence of the denaturant. The low affinity of DR_0463 for the Ni2+ matrix of the HisTrap column proved to be problematic when trying to obtain homogeneity. However, by sequentially repeating IMAC purification up to three times with the same protein sample, a large proportion of impurities were removed.
SP_1648 (PsaB) is an ATP-binding protein that forms part of the Mn-ATP transport system in S. pneumoniae and its homologue from D. radiodurans, DR_2284 is predicted to share similar function. Purification of soluble SP_1648, expressed in B834(DE3) cells, was complicated by an inability to bind the protein to the column matrix for IMAC. In the case of DR_2284, expression trials yielded only a minute amount of insoluble protein in BL21-AI competent cells. The bottlenecks in early expression and purification stages provided valuable experience in dealing with problematic proteins.
As an introduction to molecular cloning, two genes predicted to encode integral membrane proteins from D. radiodurans, were cloned for preliminary expression trials. This work was carried out at the ESRF and contributed to an extension of the structural genomics project, to incorporate membrane protein targets from D. radiodurans. Full length forms of the genes thought to encode an undecaprenyl diphosphatase (UDP) and a diacylglycerol kinase (DGKA) were successfully cloned in to pET-28b, with incorporation of separate N- and C- terminal 6xHis tags
Early post parturient changes in milk acute phase proteins
The periparturient period is one of the most critical periods in the productive life of a dairy cow, and
is the period when dairy cows are most susceptible to developing new intramammary infections
(IMI) leading to mastitis. Acute phase proteins (APP) such as haptoglobin (Hp), mammary associated
serum amyloid A3 (M-SAA3) and C-reactive protein (CRP) have been detected in milk during mastitis
but their presence in colostrum and milk in the immediate postpartum period has had limited investigation.
The hypothesis was tested that APP are a constituent of colostrum and milk during this
period. Enzyme linked immunosorbent assays (ELISAs) were used to determine each APP’s concentration
in colostrum and milk collected daily from the first to tenth day following calving in 22
Holstein-Friesian dairy cows. Haptoglobin was assessed in individual quarters and composite
milk samples while M-SAA3 and CRP concentration were determined in composite milk samples.
Change in Hp in relation to the high abundance proteins during the transition from colostrum to
milk were evaluated by 1 and 2 dimension electrophoresis and western blot. In 80% of the cows
all APPs were detected in colostrum on the first day following parturition at moderately high
levels but gradually decreased to minimal values in the milk by the 6th day after calving. The remaining
cows (20%) showed different patterns in the daily milk APP concentrations and when an elevated
level is detected could reflect the presence of IMI. Demonstration that APP are present in
colostrum and milk following parturition but fall to low levels within 4 days means that elevated
APP after this time could be biomarkers of post parturient mastitis allowing early intervention to
reduce disease on dairy farms
The geology and palaeontology of the Jurassic rocks of Eathie (Cromarty)
1. The Jurassic rocks at Eathie Haven have been downfaulted
against the pre-Mesozoic rocks with which they are in contact
to the west.
2. With the exception of the rocks at Bow Buoy Skerry, which
are of Upper Oxford Clay age, the Jurassic rocks exposed at
Eathie are Lower Kimmeridgian. Three successive ammonite zones
have been identified in the Kimmeridgian deposits: the zones
of Rasenia cymodoce and Amoeboceras kitchini, Rasenia uralensis,
and Rasenia pseadomutabilis.
3. The presence of 'marker beds' in the Kimmeridge shales
enables them to be mapped and their stratigraphical succession
determined.
4. Lines of weakness were developed in the Kimmeridgian strata
by earth-movements during late Kimmeridgian times. Sand was
injected along these lines of weakness, probably under pressure
from below. The loose sand was consolidated after injection by
the growth of calcite cement to form 'sandstone dykes' and
'sandstone sills'.
5. A rich microfauna is present in the Kimmeridgian rocks, ten
genera of foraminifera and two of Radiolaria having been found.
6. Eight lamellibranch species were identified in the Kimmerig
gian rocks, three new species being described. J. Weir's
suggestion that Lima concentrica (J. de C. Sow) might be a
synonym for Buchia concentrica (Rouillier) is confirmed.
7. One horizon of the Kimmeridgian yielded three species of
gastropoda.
8. Ten ammonite species were obtained from the Kimmeridgian
rocks, five Cardioceratids and five Perisphinctids. Prorasenia
spp. were found in association with species of the 1 asenia
uralensis group.
9. The Kimmeridgian yielded three Belemnite species including
Pachyteuthis abbreviatus.
10. The Kimmeridgian rocks appear to have been deposited in a
tranquil sea of moderate depth which cannot have been far from
land.
11. The presence of a mixed Boreal and Mediterranean faunal
assemblage at Eathie in north -east Scotland suggests that a sea
connection existed between the Boreal and Mediterranean provinces,
the gradual change of aspect of the ammonite assemblage
between southern England and Greenland being due to the influence
of climatic zones
Structural fingerprints of transcription factor binding site regions
Fourier transforms are a powerful tool in the prediction of DNA sequence properties, such as the presence/absence of codons. We have previously compiled a database of the structural properties of all 32,896 unique DNA octamers. In this work we apply Fourier techniques to the analysis of the structural properties of human chromosomes 21 and 22 and also to three sets of transcription factor binding sites within these chromosomes. We find that, for a given structural property, the structural property power spectra of chromosomes 21 and 22 are strikingly similar. We find common peaks in their power spectra for both Sp1 and p53 transcription factor binding sites. We use the power spectra as a structural fingerprint and perform similarity searching in order to find transcription factor binding site regions. This approach provides a new strategy for searching the genome data for information. Although it is difficult to understand the relationship between specific functional properties and the set of structural parameters in our database, our structural fingerprints nevertheless provide a useful tool for searching for function information in sequence data. The power spectrum fingerprints provide a simple, fast method for comparing a set of functional sequences, in this case transcription factor binding site regions, with the sequences of whole chromosomes. On its own, the power spectrum fingerprint does not find all transcription factor binding sites in a chromosome, but the results presented here show that in combination with other approaches, this technique will improve the chances of identifying functional sequences hidden in genomic data
Sponsorship of paediatric associations by manufacturers of breastmilk substitutes
No abstract available
Effect of pre-analytical treatments on bovine milk acute phase proteins
Background
Samples for diagnostic procedures often require some form of pre-analytical preparation for preservation or safe handling during transportation prior to analysis in the laboratory. This is particularly important for milk samples which frequently need preservatives to retain milk composition as close to that found in freshly collected samples as possible.
Methods
Milk samples were treated by heating at 56 °C for 30 min or preserved by addition of either potassium dichromate or bronopol respectively. Haptoglobin (Hp), mammary associated serum amyloid A3 (M-SAA3) and C-reactive protein (CRP) were measured in the various treatment groups and in control samples which were not treated, using enzyme linked immunoassays. The concentrations of each APP were compared between treated and non-treated groups using the Wilcoxon signed ranks tests.
Results
Heat treatment of samples was found to have a significant lowering effect on milk M-SAA3 and CRP but not Hp. The use of potassium dichromate and bronopol as preservatives in milk had no significant effects on milk Hp and M-SAA3 concentration but lowered milk CRP values compared to controls.
Conclusions
The observed effects of heating and preservative use on milk APP should be taken into consideration when assaying samples which have undergone heat treatment as a result of international transfer regulations involving biological samples or samples needing chemical preservation prior to transport to laboratory
Introduction: Toward an Anthropology of Affect and Evocative Ethnography
A growing interest in affect holds much promise for anthropology by providing a new frame to examine and articulate subjective and intersubjective states, which are key parts of human consciousness and behavior. Affect has its roots in the social, an observation that did not go unnoticed by Durkheim and since then kept in view by those social scientists interested in the emotions, feelings, and subjectivity. However, the challenge for ethnographers has always been to articulate in words and conceptualize theoretically what is only felt and sensed. What we are calling "evocative ethnography" is an ethnography that meets this challenge to make room for, and hold onto, feelings and affect in its description and explanation. The papers in this special issue accomplish that, as well as, provide some anthropological insights into affect theory
Letter from C.L. W[aterston] to [Jeanne C.] Carr, 1871 Jul 10.
71 Chester Square, Boston,July 10, 1871.Dear Mrs. Carr,On my return a few days ago from a journey I found a letter directed by you, and containing two letters from Mr. Muir to yourself. I searched in vain for any word from yourself, and as the letter was postmarked \u27Boston\u27 I presume you gave them hurriedly to some friend on his way here. I thank you much for the privilege of reading these letters -- they are poems of great and exquisite beauty -- worthy to be written out of a heart whose close communion with nature springs to a perfect love. \u27Too near to God for doubt or fear,He shares the eternal calm\u27.It is delightful to me to know that there is such a soul among those wonderful sky ceiled rocks , amid those great visions, the great white throne of the Central Dome. I feel His glory who could make a world,Yet in the lost depth of the wildernessLeave not a flower unfinished .What rest, what perfect trust, we ought to feel in such a Father of Nature, Soul and Spirit.I trust such healing wings have closed around your wounded spirit and carried you up to the serene heights of Peace. You can hardly resist the call to the Yosemite. How I wish I could join you there, with Mr. Muir for a guide. I am glad he met Mr. Emerson. I only wonder how Mr. E. could resist camping out under the Great Trees.A year has passed since we were at the Yosemite -- a year -- it seems hardly a day. I have a picture of the Sentinel Rock, hanging opposite my room. It is by Mr. Shapleigh, who was in the Valley with us. I chose it from all his sketches, and call it my Rock. It is indeed the Rock which is higher than I, and typifies many things spiritual and eternal, while recalling the great original at whose foot we dwelt.I should like to keep Mr. Muir\u27s letters until I hear from you again, so do not enclose them -- they are safe and much prized.Mr. Waterston and I have just returned from a five weeks\u27 trip to the Green Mts., where we have enjoyed ourselves very highly. We spent a day or two to Brandon, but unfortunately Charlie Sanderson had not arrived at his cottage. We walked to it and looked in at the window and saw white muslin curtains, a print of Beethoven and other tokens of its master\u27s pure and peaceful soul. I slipped a card under the door and took a rosebud from a bush near it. A note from Perabo tells me he is just going to join C. S. there. I met Mrs. Mary Parkman this spring, and spoke to her of my having seen you in California. She did not know where you were residing. She desired me to give you her kind regards, and remembered with interest your kindness and regard for her husband. Mr. Waterston met Ole Bull one evening at a Club where he seemed very bright and happy -- the baby must seem like a grandchild to him, as indeed it should be.We returned for the closing exercises of the schools, as Mr. W. is on the committee and we have just entertained at our house the graduating class of the Everett School - 55 girls -- a rose garden of girls they looked in their white muslins. How does your University and various interests progress? Mr. W. had a very interesting letter from Mr. Bacon lately, who writes many pleasant things. I wish Oakland was not three thousand miles off!So they sentenced Mrs. Fair -- it was more than I expected. If anyone deserves capital punishment it would seem to be in such a case, and yet -- well, God knows how to deal with sinners better than we do.Mrs. Howison is out of town. I saw her bright face just before we all went away. Hoping to hear from you soon, we send many best loves. I go this week to Newport to stay with my sister, but our letters are sent here.Ever yours,C. L. W[aterston]4600408
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