3,786 research outputs found
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Remembering 7/7: the collective shaping of survivors' personal memories of the 2005 London bombing
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Altered brain connectivity in sudden unexpected death in epilepsy (SUDEP) revealed using resting-state fMRI.
The circumstances surrounding SUDEP suggest autonomic or respiratory collapse, implying central failure of regulation or recovery. Characterisation of the communication among brain areas mediating such processes may shed light on mechanisms and noninvasively indicate risk. We used rs-fMRI to examine network properties among brain structures in people with epilepsy who suffered SUDEP (n = 8) over an 8-year follow-up period, compared with matched high- and low-risk subjects (n = 16/group) who did not suffer SUDEP during that period, and a group of healthy controls (n = 16). Network analysis was employed to explore connectivity within a 'regulatory-subnetwork' of brain regions involved in autonomic and respiratory regulation, and over the whole-brain. Modularity, the extent of network organization into separate modules, was significantly reduced in the regulatory-subnetwork, and the whole-brain, in SUDEP and high-risk. Increased participation, a local measure of inter-modular belonging, was evident in SUDEP and high-risk groups, particularly among thalamic structures. The medial prefrontal thalamus was increased in SUDEP compared with all other control groups, including high-risk. Patterns of hub topology were similar in SUDEP and high-risk, but were more extensive in low-risk patients, who displayed greater hub prevalence and a radical reorganization of hubs in the subnetwork. SUDEP is associated with reduced functional organization among cortical and sub-cortical brain regions mediating autonomic and respiratory regulation. Living high-risk subjects demonstrated similar patterns, suggesting such network measures may provide prospective risk-indicating value, though a crucial difference between SUDEP and high-risk was altered connectivity of the medial thalamus in SUDEP, which was also elevated compared with all sub-groups. Disturbed thalamic connectivity may reflect a potential non-invasive marker of elevated SUDEP risk
The Leeway of Shipping Containers at Different Immersion Levels
The leeway of 20-foot containers in typical distress conditions is
established through field experiments in a Norwegian fjord and in open-ocean
conditions off the coast of France with wind speed ranging from calm to 14 m/s.
The experimental setup is described in detail and certain recommendations given
for experiments on objects of this size. The results are compared with the
leeway of a scaled-down container before the full set of measured leeway
characteristics are compared with a semi-analytical model of immersed
containers. Our results are broadly consistent with the semi-analytical model,
but the model is found to be sensitive to choice of drag coefficient and makes
no estimate of the cross-wind leeway of containers. We extend the results from
the semi-analytical immersion model by extrapolating the observed leeway
divergence and estimates of the experimental uncertainty to various realistic
immersion levels. The sensitivity of these leeway estimates at different
immersion levels are tested using a stochastic trajectory model. Search areas
are found to be sensitive to the exact immersion levels, the choice of drag
coefficient and somewhat less sensitive to the inclusion of leeway divergence.
We further compare the search areas thus found with a range of trajectories
estimated using the semi-analytical model with only perturbations to the
immersion level. We find that the search areas calculated without estimates of
crosswind leeway and its uncertainty will grossly underestimate the rate of
expansion of the search areas. We recommend that stochastic trajectory models
of container drift should account for these uncertainties by generating search
areas for different immersion levels and with the uncertainties in crosswind
and downwind leeway reported from our field experiments.Comment: 25 pages, 11 figures and 5 tables; Ocean Dynamics, Special Issue on
Advances in Search and Rescue at Sea (2012
Altered brain connectivity in sudden unexpected death in epilepsy (SUDEP) revealed using resting-state fMRI
The circumstances surrounding SUDEP suggest autonomic or respiratory collapse, implying central failure of regulation or recovery. Characterisation of the communication among brain areas mediating such processes may shed light on mechanisms and noninvasively indicate risk.
We used rs-fMRI to examine network properties among brain structures in people with epilepsy who suffered SUDEP (n = 8) over an 8-year follow-up period, compared with matched high- and low-risk subjects (n = 16/group) who did not suffer SUDEP during that period, and a group of healthy controls (n = 16). Network analysis was employed to explore connectivity within a ‘regulatory-subnetwork’ of brain regions involved in autonomic and respiratory regulation, and over the whole-brain.
Modularity, the extent of network organization into separate modules, was significantly reduced in the regulatory-subnetwork, and the whole-brain, in SUDEP and high-risk. Increased participation, a local measure of inter-modular belonging, was evident in SUDEP and high-risk groups, particularly among thalamic structures. The medial prefrontal thalamus was increased in SUDEP compared with all other control groups, including high-risk. Patterns of hub topology were similar in SUDEP and high-risk, but were more extensive in low-risk patients, who displayed greater hub prevalence and a radical reorganization of hubs in the subnetwork.
SUDEP is associated with reduced functional organization among cortical and sub-cortical brain regions mediating autonomic and respiratory regulation. Living high-risk subjects demonstrated similar patterns, suggesting such network measures may provide prospective risk-indicating value, though a crucial difference between SUDEP and high-risk was altered connectivity of the medial thalamus in SUDEP, which was also elevated compared with all sub-groups. Disturbed thalamic connectivity may reflect a potential non-invasive marker of elevated SUDEP risk
Canine pseudopregnancy: an evaluation of prevalence and current treatment protocols in the UK
Background: There is a dearth of literature on pseudopregnancy in the bitch, with only a few treatment-based
studies published since the 1990s. Pseudopregnancy may be under-recognised in bitches and may account for a
proportion of behavioural cases seen in veterinary practices including aggression. Little is known about commonly
used treatments for overtly pseudopregnant bitches and it is possible that current regimes may not be prescribed
for a sufficient duration to control any clinical signs including, physical and behavioural changes. To investigate
current trends in diagnosis and treatment of canine pseudopregnancy, a postal survey was sent to 2000 randomly
selected veterinary surgeons in UK veterinary practices. The questionnaire queried how often vets recognise cases
of pseudopregnancy in spayed and entire bitches, which physical or behavioural signs are commonly recognised
for diagnosis, and which management or treatment protocols are used.
Results: The response rate was 19.8% (397/2000). Ninety-six percent of veterinary surgeons reported seeing
pseudopregnant bitches showing behavioural changes without any physical changes within the last 12 months.
Of those behavioural changes, collecting and mothering objects was the most frequently reported behavioural
sign (96%). Ninety-seven percent of vets had seen aggression in pseudopregnant bitches. Nevertheless, only 52%
of vets routinely asked owners about behavioural changes during consultations. Forty-nine percent of respondents
reported seeing pseudopregnancy in spayed bitches. The most commonly reported physical sign was enlarged
mammary glands and/or milk production (89%). Treatment options varied (surgical, medical or none) and depended on
duration and severity of physical and behavioural signs, owners’ preference, cost, concurrent disease, drug availability
and previous history.
Conclusions: This is the largest epidemiological study of canine pseudopregnancy in the UK. The prevalence and
severity of clinical signs in dogs with pseudopregnancy are variable and possibly under-estimated. Dogs with overt
pseudopregnancy experience diverse physical and behavioural changes and information on standard treatment
protocols are lacking. Although, progress on our understanding of diagnosis and treatment of pseudopregnancy in
spayed and entire bitches has been made, further studies are warranted
Distinct Patterns of Brain Metabolism in Patients at Risk of Sudden Unexpected Death in Epilepsy
Objective: To characterize regional brain metabolic differences in patients at high risk of sudden unexpected death in epilepsy (SUDEP), using fluorine-18-fluorodeoxyglucose positron emission tomography (18FDG-PET). Methods: We studied patients with refractory focal epilepsy at high (n = 56) and low (n = 69) risk of SUDEP who underwent interictal 18FDG-PET as part of their pre-surgical evaluation. Binary SUDEP risk was ascertained by thresholding frequency of focal to bilateral tonic-clonic seizures (FBTCS). A whole brain analysis was employed to explore regional differences in interictal metabolic patterns. We contrasted these findings with regional brain metabolism more directly related to frequency of FBTCS. Results: Regions associated with cardiorespiratory and somatomotor regulation differed in interictal metabolism. In patients at relatively high risk of SUDEP, fluorodeoxyglucose (FDG) uptake was increased in the basal ganglia, ventral diencephalon, midbrain, pons, and deep cerebellar nuclei; uptake was decreased in the left planum temporale. These patterns were distinct from the effect of FBTCS frequency, where increasing frequency was associated with decreased uptake in bilateral medial superior frontal gyri, extending into the left dorsal anterior cingulate cortex. Significance: Regions critical to cardiorespiratory and somatomotor regulation and to recovery from vital challenges show altered interictal metabolic activity in patients with frequent FBTCS considered to be at relatively high-risk of SUDEP, and shed light on the processes that may predispose patients to SUDEP
Comets, historical records and vedic literature
A verse in book I of Rigveda mentions a cosmic tree with rope-like aerial
roots held up in the sky. Such an imagery might have ensued from the appearance
of a comet having `tree stem' like tail, with branched out portions resembling
aerial roots. Interestingly enough, a comet referred to as `heavenly tree' was
seen in 162 BC, as reported by old Chinese records. Because of weak surface
gravity, cometary appendages may possibly assume strange shapes depending on
factors like rotation, structure and composition of the comet as well as solar
wind pattern. Varahamihira and Ballala Sena listed several comets having
strange forms as reported originally by ancient seers such as Parashara,
Vriddha Garga, Narada and Garga.
Mahabharata speaks of a mortal king Nahusha who ruled the heavens when Indra,
king of gods, went into hiding. Nahusha became luminous and egoistic after
absorbing radiance from gods and seers. When he kicked Agastya (southern star
Canopus), the latter cursed him to become a serpent and fall from the sky. We
posit arguments to surmise that this Mahabharata lore is a mythical recounting
of a cometary event wherein a comet crossed Ursa Major, moved southwards with
an elongated tail in the direction of Canopus and eventually went out of sight.
In order to check whether such a conjecture is feasible, a preliminary list of
comets (that could have or did come close to Canopus) drawn from various
historical records is presented and discussed.Comment: This work was presented in the International Conference on Oriental
Astronomy held at IISER, Pune (India) during November, 201
Mouse Estrous Cycle Identification Tool and Images
The efficiency of producing timed pregnant or pseudopregnant mice can be increased by identifying those in proestrus or estrus. Visual observation of the vagina is the quickest method, requires no special equipment, and is best used when only proestrus or estrus stages need to be identified. Strain to strain differences, especially in coat color can make it difficult to determine the stage of the estrous cycle accurately by visual observation. Presented here are a series of images of the vaginal opening at each stage of the estrous cycle for 3 mouse strains of different coat colors: black (C57BL/6J), agouti (CByB6F1/J) and albino (BALB/cByJ). When all 4 stages (proestrus, estrus, metestrus, and diestrus) need to be identified, vaginal cytology is regarded as the most accurate method. An identification tool is presented to aid the user in determining the stage of estrous when using vaginal cytology. These images and descriptions are an excellent resource for learning how to determine the stage of the estrous cycle by visual observation or vaginal cytology
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