760 research outputs found
The development of the pharyngeal region in the dog
The morphogenesis of the pharyngeal region is
believed to be involved in the occurrence of so-called
"Branchial Cysts", a condition affecting human and canine
adolescents of comparable age, and which is characterised
by the appearance of cystic lesions on the lateral aspects
of the upper portion of the neck. These lesions are
usually small in the human, while in the dog, due to the
presence of a hair coat, they remain undiscovered until
they have become large and pendulous. It is generally
believed that branchial cysts arise from remnants of the
branchial apparatus which are induced to proliferate by
certain hormonal combinations present in the young
individual. Investigators (Bhaskar and Bernier, 1959)»
who recently examined a large number of human lesions deny
a purely branchiogenic origin however, and postulate that
epithelial remnants of bronchial or, what is more likely,
parotid origin, after becoming trapped in developing lymph
nodes, produce this condition, which according to their
view should be renamed "Benign Lymphoepithelial Cysts".Investigations into the etiology of branchial cysts
in the dog, at present being carried out at the author's
home university (Ontario Veterinary College, University of
Toronto), became focused on the developmental processes of
the pharyngeal region in that animal, because experience
with the human condition suggested a developmental defect.
2
A search of the literature available to the author revealed
that the development of the canine pharyngeal region was
practically unknown, only some selected aspects such as the
early development of the thyroid and parathyroids having
been described by Godwin (193^S 1937 a) of the Kingsbury
school. It was uncovered further that the developmental
anatomy of the dog as a whole had scarcely been studied,
which is surprising in view of this animal's importance to
the veterinary surgeon and to the research worker.The present study, then, was undertaken in an attempt
to close the obvious gap in our knowledge of canine
embryogenesis, and to provide those interested in the
etiology of branchial cysts with what might be considered
a working basis for further clinical and embryological
examinations. It was found necessary to survey the entire
field of pharyngeal development, from the appearance of a
foregut to conditions found at full term, since confinement
of the field, even though it could have been explored to
much greater depth, would have proved useful neither to
those interested in canine embryology nor to those studying
branchial cysts. The former would find that the large gap
in the knowledge of this region still persisted and the
latter would not be able to select the particular
anatomical region or developmental stage which may interest
them for further scrutiny.The lack of previous work on canine development and
subsequent absence of known standards of developmental
reference made it necessary to devote much space to the
description and staging of the einbryological material prior
to sectioning. The hulk of the thesis however is devoted
to the description of the developmental processes observed
in the pharyngeal region, and minor points worthy of short
discussion are dealt with here, because it was thought that
due to the wide field covered in this study a separate
discussion would appear rather disjointed. Major
anatomical areas however have been extracted from this
section and are presented at the end in the form of
REGIONAL REVIEWS
Individual-specific changes in the human gut microbiota after challenge with enterotoxigenic Escherichia coli and subsequent ciprofloxacin treatment
Acknowledgements The authors wish to thank Mark Stares, Richard Rance, and other members of the Wellcome Trust Sanger Institute’s 454 sequencing team for generating the 16S rRNA gene data. Lili Fox Vélez provided editorial support. Funding IA, JNP, and MP were partly supported by the NIH, grants R01-AI-100947 to MP, and R21-GM-107683 to Matthias Chung, subcontract to MP. JNP was partly supported by an NSF graduate fellowship number DGE750616. IA, JNP, BRL, OCS and MP were supported in part by the Bill and Melinda Gates Foundation, award number 42917 to OCS. JP and AWW received core funding support from The Wellcome Trust (grant number 098051). AWW, and the Rowett Institute of Nutrition and Health, University of Aberdeen, receive core funding support from the Scottish Government Rural and Environmental Science and Analysis Service (RESAS).Peer reviewedPublisher PD
Children of prisoners: exploring the impact of families' reappraisal of the role and status of the imprisoned parent on children's coping strategies
Qualitative data from a larger study on the impact of parental imprisonment in four countries found that children of prisoners face fundamentally similar psychological and social challenges. The ways that children cope, however, are influenced by the interpretative frame adopted by the adults around them, and by how issues of parental imprisonment are talked about in their families. This article argues that families have to reappraise their view of the imprisoned parent and then decide on their policy for how to deal with this publicly. Their approach may be based on openness and honesty or may emphasise privacy and secrecy, or a combination of these. Children are likely to be influenced by their parents'/carers' views, although these may cause conflict for them. Where parents/carers retain a positive view of the imprisoned parent, children are likely to benefit; where parents/carers feel issues of shame and stigma acutely, this is likely to be transmitted to their children. This is important for social workers and practitioners involved in supporting prisoners' families and for parenting programmes
B-cell-specific Myd88 L252P expression causes a premalignant gammopathy resembling IgM MGUS
A highly recurrent somatic L265P mutation in the TIR domain of the signaling adapter MYD88 constitutively activates NF-κB. It occurs in nearly all human patients with Waldenström's macroglobulinemia (WM), a B cell malignancy caused by IgM-expressing cells. Here, we introduced an inducible leucine to proline point mutation into the mouse Myd88 locus, at the orthologous position L252P. When the mutation was introduced early during B cell development, B cells developed normally. However, IgM-expressing plasma cells accumulated with age in spleen and bone, leading to more than 20-fold elevated serum IgM titers. When introduced into germinal center B cells in the context of an immunization, the Myd88(L252P) mutation caused prolonged persistence of antigen-specific serum IgM and elevated numbers of antigen-specific IgM plasma cells. Myd88(L252P)-expressing B cells switched normally, but plasma cells expressing other immunoglobulin isotypes did not increase in numbers, implying that IgM expression may be required for the observed cellular expansion. In order to test whether the Myd88(L252P) mutation can cause clonal expansions, we introduced it into a small fraction of CD19-positive B cells. In this scenario, five out of five mice developed monoclonal IgM serum paraproteins accompanied by an expansion of clonally related plasma cells that expressed mostly hypermutated VDJ regions. Taken together, our data suggest that the Myd88(L252P) mutation is sufficient to promote aberrant survival and expansion of IgM-expressing plasma cells which in turn can cause IgM monoclonal gammopathy of undetermined significance (MGUS), the premalignant condition that precedes WM
In-medium modifications of the interaction in photon-induced reactions
Differential cross sections of the reactions
and have been measured for several
nuclei (H,C, and Pb) at an incident-photon energy of
=400-460 MeV at the tagged-photon facility at MAMI-B using the TAPS
spectrometer. A significant nuclear-mass dependence of the
invariant-mass distribution is found in the channel. This
dependence is not observed in the channel and is
consistent with an in-medium modification of the interaction in the
==0 channel. The data are compared to -induced measurements and to
calculations within a chiral-unitary approach
Planning and Leveraging Event Portfolios: Towards a Holistic Theory
This conceptual paper seeks to advance the discourse on the leveraging and legacies of events by examining the planning, management, and leveraging of event portfolios. This examination shifts the common focus from analyzing single events towards multiple events and purposes that can enable cross-leveraging among different events in pursuit of attainment and magnification of specific ends. The following frameworks are proposed: (1) event portfolio planning and leveraging, and (2) analyzing events networks and inter-organizational linkages. These frameworks are intended to provide, at this infancy stage of event portfolios research, a solid ground for building theory on the management of different types and scales of events within the context of a portfolio aimed to obtain, optimize and sustain tourism, as well as broader community benefits
Alpha-band rhythms in visual task performance: phase-locking by rhythmic sensory stimulation
Oscillations are an important aspect of neuronal activity. Interestingly, oscillatory patterns are also observed in behaviour, such as in visual performance measures after the presentation of a brief sensory event in the visual or another modality. These oscillations in visual performance cycle at the typical frequencies of brain rhythms, suggesting that perception may be closely linked to brain oscillations. We here investigated this link for a prominent rhythm of the visual system (the alpha-rhythm, 8-12 Hz) by applying rhythmic visual stimulation at alpha-frequency (10.6 Hz), known to lead to a resonance response in visual areas, and testing its effects on subsequent visual target discrimination. Our data show that rhythmic visual stimulation at 10.6 Hz: 1) has specific behavioral consequences, relative to stimulation at control frequencies (3.9 Hz, 7.1 Hz, 14.2 Hz), and 2) leads to alpha-band oscillations in visual performance measures, that 3) correlate in precise frequency across individuals with resting alpha-rhythms recorded over parieto-occipital areas. The most parsimonious explanation for these three findings is entrainment (phase-locking) of ongoing perceptually relevant alpha-band brain oscillations by rhythmic sensory events. These findings are in line with occipital alpha-oscillations underlying periodicity in visual performance, and suggest that rhythmic stimulation at frequencies of intrinsic brain-rhythms can be used to reveal influences of these rhythms on task performance to study their functional roles
- …