A taste of the deep-sea: The roles of gustatory and tactile searching behaviour in the grenadier fish <i>Coryphaenoides armatus</i>

The deep-sea grenadier fishes (Coryphaenoides spp.) are among the dominant predators and scavengers in the ocean basins that cover much of Earth's surface. Baited camera experiments were used to study the behaviour of these fishes. Despite the apparent advantages of rapidly consuming food, grenadiers attracted to bait spend a large proportion of their time in prolonged periods of non-feeding activity. Video analysis revealed that fish often adopted a head-down swimming attitude (mean of 21.3 degrees between the fish and seafloor), with swimming velocity negatively related to attitude. The fish also swam around and along vertical and horizontal structures of the lander with their head immediately adjacent to the structure. We initially hypothesised that this behaviour was associated with the use of the short chin barbel in foraging. Barbel histology showed numerous taste buds in the skin, and a barbel nerve with about 20,000 axons in adult fish. A tracing experiment in one undamaged animal revealed the termination fields of the barbel neurons in the trigeminal and rhombencephalic regions, indicating both a mechanoreceptory and a gustatory role for the barbel. Our conclusion was that olfactory foraging becomes ineffective at close ranges and is followed by a search phase using tactile and gustatory sensing by the barbel. The development of this sensory method probably co-evolved alongside behavioural changes in swimming mechanics to allow postural stability at low swimming speeds

The d' dibaryon in the quark-delocalization, color-screening model

We study the questions of the existence and mass of the proposed $d' (IJ^P=00^-)$ dibaryon in the quark-delocalization, color-screening model (QDCSM). The transformation between physical and symmetry bases has been extended to the cases beyond the SU(2) orbital symmetry. Using parameters fixed by baryon properties and $NN$ scattering, we find a mild attraction in the $IJ^P=00^-$ channel, but it is not strong enough to form a deeply bound state as proposed for the $d'$ state. Nor does the (isospin) I=2 N$\Delta$ configuration have a deeply bound state. These results show that if a narrow dibaryon $d'$ state does exist, it must have a more complicated structure.Comment: 12 pp. latex, no figs., 2 tables, additional refs., Report-no was adde

Fermion Masses, Mixing Angles and Supersymmetric SO(10) Unification

We reanalyse the problem of fermion masses in supersymmetric SO(10) grand unified models. In the minimal model, both low energy Higgs doublets belong to the same {\bf{10}} representation of SO(10) implying the unification not only of the gauge but also of the third generation Yukawa couplings. These models predict large values of $\tan\beta \sim 50$. In this paper we study the effects of departing from the minimal conditions in order to see if we can find models with a reduced value of $\tan\beta$. In order to maintain predictability, however, we try to do this with the addition of only one new parameter. We still assume that the fermion masses arise from interactions of the spinor representations with a single ${\bf 10}$ representation, but this ${\bf 10}$ now only contains a part of the two light Higgs doublets. This enables us to introduce one new parameter $\omega=\lambda_b/\lambda_t$. For values of $\omega \ll 1$ we can in principle reduce the value of $\tan\beta$. In fact, $\omega$ is an overall factor which multiplies the down quark and charged lepton Yukawa matrices. Thus the theory is still highly constrained. We show that the first generation quark masses and the CP-violation parameter $\epsilon_K$ yield strong constraints on the phenomenologically allowed models. In the end, we find that large values of $\tan\beta$ are still preferred.Comment: 15 pages, latex, 6 uuencoded figure

REM Sleep, Prefrontal Theta, and the Consolidation of Human Emotional Memory

Both emotion and sleep are independently known to modulate declarative memory. Memory can be facilitated by emotion, leading to enhanced consolidation across increasing time delays. Sleep also facilitates offline memory processing, resulting in superior recall the next day. Here we explore whether rapid eye movement (REM) sleep, and aspects of its unique neurophysiology, underlie these convergent influences on memory. Using a nap paradigm, we measured the consolidation of neutral and negative emotional memories, and the association with REM-sleep electrophysiology. Subjects that napped showed a consolidation benefit for emotional but not neutral memories. The No-Nap control group showed no evidence of a consolidation benefit for either memory type. Within the Nap group, the extent of emotional memory facilitation was significantly correlated with the amount of REM sleep and also with right-dominant prefrontal theta power during REM. Together, these data support the role of REM-sleep neurobiology in the consolidation of emotional human memories, findings that have direct translational implications for affective psychiatric and mood disorders

FIRE (facilitating implementation of research evidence) : a study protocol

Research evidence underpins best practice, but is not always used in healthcare. The Promoting Action on Research Implementation in Health Services (PARIHS) framework suggests that the nature of evidence, the context in which it is used, and whether those trying to use evidence are helped (or facilitated) affect the use of evidence. Urinary incontinence has a major effect on quality of life of older people, has a high prevalence, and is a key priority within European health and social care policy. Improving continence care has the potential to improve the quality of life for older people and reduce the costs associated with providing incontinence aids

Lack of Effect of Induction of Hypothermia after Acute Brain Injury

Background Induction of hypothermia in patients with brain injury was shown to improve outcomes in small clinical studies, but the results were not definitive. To study this issue, we conducted a multicenter trial comparing the effects of hypothermia with those of normothermia in patients with acute brain injury. Methods The study subjects were 392 patients 16 to 65 years of age with coma after sustaining closed head injuries who were randomly assigned to be treated with hypothermia (body temperature, 33°C), which was initiated within 6 hours after injury and maintained for 48 hours by means of surface cooling, or normothermia. All patients otherwise received standard treatment. The primary outcome measure was functional status six months after the injury. Results The mean age of the patients and the type and severity of injury in the two treatment groups were similar. The mean (±SD) time from injury to randomization was 4.3±1.1 hours in the hypothermia group and 4.1±1.2 hours in the normothermia group, and the mean time from injury to the achievement of the target temperature of 33°C in the hypothermia group was 8.4±3.0 hours. The outcome was poor (defined as severe disability, a vegetative state, or death) in 57 percent of the patients in both groups. Mortality was 28 percent in the hypothermia group and 27 percent in the normothermia group (P=0.79). The patients in the hypothermia group had more hospital days with complications than the patients in the normothermia group. Fewer patients in the hypothermia group had high intracranial pressure than in the normothermia group. Conclusions Treatment with hypothermia, with the body temperature reaching 33°C within eight hours after injury, is not effective in improving outcomes in patients with severe brain injury. (N Engl J Med 2001; 344:556-63.

Detection of superhumps in XTE J1118+480 approaching quiescence

We present the results of our monitoring of the halo black-hole soft X-ray transient (SXT) XTE J1118+480 during its decline to quiescence. The system has decayed 0.5 mags from December 2000 to its present near quiescent level at R=18.65 (June 2001). The ellipsoidal lightcurve is distorted by an additional modulation that we interpret as a superhump of P_sh=0.17049(1) d i.e. 0.3% longer than the orbital period. This implies a disc precession period P_prec= 52 d. After correcting the average phase-folded light curve for veiling, the amplitude difference between the minima suggests that the binary inclination angle lies in the range i=71-82 deg. However, we urge caution in the interpretation of these values because of residual systematic contamination of the ellipsoidal lightcurve by the complex form of the superhump modulation. The orbital--mean H-alpha profiles exhibit clear velocity variations with ~500 km/s amplitude. We interpret this as the first spectroscopic evidence of an eccentric precessing disc.Comment: Accepted for publication in MNRA

Taking stock of gene therapy for cystic fibrosis

The identification of the cystic fibrosis (CF) gene opened the way for gene therapy. In the ten years since then, proof of principle in vitro and then in animal models in vivo has been followed by numerous clinical studies using both viral and non-viral vectors to transfer normal copies of the gene to the lungs and noses of CF patients. A wealth of data have emerged from these studies, reflecting enormous progress and also helping to focus and define key difficulties that remain unresolved. Gene therapy for CF remains the most promising possibility for curative rather than symptomatic therapy