The tuberomammillary nucleus (TM) located in the posterior part of the hypothalamus is the main source of neuronal histamine in the central nervous system. Recent work from our laboratories has ...indicated an involvement of the TM region in neuronal plasticity and reinforcement processes. In the present study, we investigated the effects of TM lesions on the performance of adult and aged Wistar rats in a set of learning tasks, which differed in terms of complexity and reward contingencies (habituation learning, inhibitory avoidance, discrimination learning, Morris water maze). An improvement was found in every test applied, indicating that TM lesions seem to generally enhance learning and memory capacities independent of the special demands of a given task. Age-related learning deficits were strongly diminished. Immunohistochemistry revealed that the excitotoxic lesions used to destroy the TM region led to a marked decrease in the number of histamine-positive neurons in the vicinity of the injection site, indicating an involvement of the brain histaminergic system in the observed behavioral changes.
To investigate the association of neonatal hypoglycaemia and hyperglycaemia with outcomes in infants with hypoxic ischaemic encephalopathy (HIE).
Post hoc analysis of the CoolCap Study.
25 perinatal ...centres in the UK, the USA and New Zealand during 1999-2002.
234 infants at ≥36 weeks' gestation with moderate-to-severe HIE enrolled in the CoolCap Study. 214 (91%) infants had documented plasma glucose and follow-up outcome data.
Infants were randomised to head cooling for 72 h starting within 6 h of birth, or standard care. Plasma glucose levels were measured at predetermined time intervals after randomisation.
The unfavourable primary outcome of the study was death and/or severe neurodevelopmental disability at 18 months. Hypoglycaemia (≤40 mg/dL, ≤2.2 mmol/L) and hyperglycaemia (>150 mg/dL, >8.3 mmol/L) during the first 12 h after randomisation were investigated for univariable and multivariable associations with unfavourable primary outcome.
121 (57%) infants had abnormal plasma glucose values within 12 h of randomisation. Unfavourable outcome was observed in 126 (60%) infants and was more common among subjects with hypoglycaemia (81%, p=0.004), hyperglycaemia (67%, p=0.01) and any glucose derangement within the first 12 h (67%, p=0.002) compared with normoglycaemic infants (48%) in univariable analysis. These associations remained significant after adjusting for birth weight, Apgar score, pH, Sarnat stage and hypothermia therapy.
Both hypoglycaemia and hyperglycaemia in infants with moderate-to-severe HIE were independently associated with unfavourable outcome. Future studies are needed to investigate the prognostic significance of these associations and their role as biomarkers of brain injury.
(ClinicalTrials.gov NCT00383305).
We investigated event‐related brain potentials (ERPs) to passive ramp movements of the knee joint. The knee movements were either attended or unattended and were either very easy or very hard to ...detect. We used special methods to ensure that movement only activated muscle spindle and joint receptors. The first movement‐related ERP started 20 ms after movement onset, and had a contralateral maximum. This initial ERP did not differ as a function of attention and movement discriminability. Signal detection analysis of the behavioral data suggested that hard‐to‐detect movements could be discriminated above chance level, but were not reported because of a decision bias. At 60–100 ms, an ERP was observed that discriminated detected from undetected hard‐to‐detect movements. Starting at 80 ms, we found an ERP that was unique to movements that were attended and easy to detect. We discuss that (1) the initial ERP reflects activation of preconscious sensory processors, (2) the second ERP may reflect detection that fails to attract attention, and (3) the third ERP reflects active focusing of attention on the movement.
The Department of Veterans Affairs (VA) has developed a new exam room design standard that is intended to facilitate a greater degree of patient centeredness. This new design includes a wall-mounted ...monitor on an armature system and a moveable table workspace. To date, however, this design has not been formally evaluated in a field setting. We conducted observations and interviews with primary care providers and their patients from three locations within the Phoenix VA Health Care System, in a pilot study comparing the new exam room design standard with the older legacy exam rooms. When using the new exam room layout, providers spent a greater proportion of time focused on the patient, spent more time in screen-sharing activities with the patient, and had a higher degree of self-reported situation awareness. However, the legacy exam rooms were perceived as better facilitating workflow integration. Provider and patient debrief interviews were supportive of the new exam room design. Overall, our field study results suggest that the new exam room design does contribute to a greater degree of patient centeredness, though more thorough evaluations are required to support these preliminary results.
We determine the neutrino mixing and mass parameters that are allowed by the Super-Kamiokande atmospheric neutrino data in a three-neutrino model with one mass-squared difference contributing to the ...oscillations. We find that although
ν
μ
→
ν
τ
oscillations are favored,
ν
μ
→
ν
e
oscillations with amplitude as large as 0.18 are allowed even after accounting for the limit from the CHOOZ reactor experiment. The range of allowed parameters permit observable
ν
μ
↔
ν
e
and
ν
e
→
ν
τ
oscillations in future long-baseline experiments.
We write the probabilities for neutrino oscillations in uniform-density matter exactly in terms of convention-independent vacuum neutrino oscillation parameters and the matter density. This extends ...earlier results formulating neutrino oscillations in terms of matter-, phase-, and trace-invariant quantities.
We evaluate the exposure during nadir observations with JEM-EUSO, the Extreme Universe Space Observatory, on-board the Japanese Experiment Module of the International Space Station. Designed as a ...mission to explore the extreme energy Universe from space, JEM-EUSO will monitor the Earth’s nighttime atmosphere to record the ultraviolet light from tracks generated by extensive air showers initiated by ultra-high energy cosmic rays. In the present work, we discuss the particularities of space-based observation and we compute the annual exposure in nadir observation. The results are based on studies of the expected trigger aperture and observational duty cycle, as well as, on the investigations of the effects of clouds and different types of background light. We show that the annual exposure is about one order of magnitude higher than those of the presently operating ground-based observatories.
The proposal to search for relic neutrinos through their absorption effect on the neutrino cosmic-ray flux is carefully examined. Resonant absorption at E(v) of about 10 to the 21st ...eV-squared/m(1+z), where m is the neutrino mass and z is the cosmological redshift of the neutrino source, has been previously predicted. However, it is shown that detection of the neutrino flux in the absorption region requires an improbable power output for a single source. A summation over a distribution of sources is then performed, using the quasar distribution as a model. This summation increases the neutrino flux but spreads the absorption dip. It is concluded that within the context of big bang cosmology, detection of relic neutrinos through their absorption effects depends crucially on whether or not there exist sources at large z, emitting a sufficient flux of ultraenergy neutrinos. The astrophysical conditions which allow detection appear very unlikely but not impossible.
By combining experimental constraints from atmospheric and solar neutrino oscillations and the tritium beta decay endpoint, we infer upper limits of 4.4 eV on the
ν
μ
and
ν
τ
masses, if the universe ...consists of three neutrinos. For hierarchical mass spectra
m
3≫
m
1,
m
2 or
m
3≃
m
2≫
m
1 we infer that
m
ν
α
≲0.08 eV for
α=
e,
μ,
τ. In a four neutrino universe, and assuming neutrino oscillations also account for the LSND experimental results,
m
ν
α
≲
5.4
eV. We also obtain lower limits on the masses.
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