215 research outputs found

    Friend or foe:Risso’s dolphins eavesdrop on conspecific sounds to induce or avoid intra-specific interaction

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    The detection and use of emitters’ signals by unintended receivers, i.e., eavesdropping, represents an important and often low-cost way for animals to gather information from their environment. Acoustic eavesdropping can be a key driver in mediating intra- and interspecific interactions (e.g., cooperation, predator–prey systems), specifically in species such as cetaceans that use sound as a primary sensory modality. While most cetacean species produce context-specific sounds, little is known about the use of those sounds by potential conspecific eavesdroppers. We experimentally tested the hypothesis that a social cetacean, Risso’s dolphin (Grampus griseus), is able to gather biologically relevant information by eavesdropping on conspecific sounds. We conducted playback experiments on free-ranging dolphins using three context-specific sounds stimuli and monitored their horizontal movement using visual or airborne focal follow observations. We broadcasted natural sequences of conspecific foraging sounds potentially providing an attractive dinner bell signal (n = 7), male social sounds simulating a risk of forthcoming agonistic interaction (n = 7) and female-calf social sounds representing no particularly threatening context (n = 7). We developed a quantitative movement response score and tested whether animals changed their direction of horizontal movement towards or away from the playback source. Dolphins approached the foraging and the social female-calf sounds whereas they avoided the social male sounds. Hence, by acoustically eavesdropping on conspecifics, dolphins can discriminate between social and behavioural contexts and anticipate potential threatening or beneficial situations. Eavesdropping and the ensuing classification of ‘friend or foe’ can thus shape intra-specific social interactions in cetaceans

    The clinical features of the piriformis syndrome: a systematic review

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    Piriformis syndrome, sciatica caused by compression of the sciatic nerve by the piriformis muscle, has been described for over 70 years; yet, it remains controversial. The literature consists mainly of case series and narrative reviews. The objectives of the study were: first, to make the best use of existing evidence to estimate the frequencies of clinical features in patients reported to have PS; second, to identify future research questions. A systematic review was conducted of any study type that reported extractable data relevant to diagnosis. The search included all studies up to 1 March 2008 in four databases: AMED, CINAHL, Embase and Medline. Screening, data extraction and analysis were all performed independently by two reviewers. A total of 55 studies were included: 51 individual and 3 aggregated data studies, and 1 combined study. The most common features found were: buttock pain, external tenderness over the greater sciatic notch, aggravation of the pain through sitting and augmentation of the pain with manoeuvres that increase piriformis muscle tension. Future research could start with comparing the frequencies of these features in sciatica patients with and without disc herniation or spinal stenosis

    Engaging communication experts in a Delphi process to identify patient behaviors that could enhance communication in medical encounters

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    <p>Abstract</p> <p>Background</p> <p>The communication literature currently focuses primarily on improving physicians' verbal and non-verbal behaviors during the medical interview. The Four Habits Model is a teaching and research framework for physician communication that is based on evidence linking specific communication behaviors with processes and outcomes of care. The Model conceptualizes basic communication tasks as "Habits" and describes the sequence of physician communication behaviors during the clinical encounter associated with improved outcomes. Using the Four Habits Model as a starting point, we asked communication experts to identify the verbal communication behaviors of patients that are important in outpatient encounters.</p> <p>Methods</p> <p>We conducted a 4-round Delphi process with 17 international experts in communication research, medical education, and health care delivery. All rounds were conducted via the internet. In round 1, experts reviewed a list of proposed patient verbal communication behaviors within the Four Habits Model framework. The proposed patient verbal communication behaviors were identified based on a review of the communication literature. The experts could: approve the proposed list; add new behaviors; or modify behaviors. In rounds 2, 3, and 4, they rated each behavior for its fit (agree or disagree) with a particular habit. After each round, we calculated the percent agreement for each behavior and provided these data in the next round. Behaviors receiving more than 70% of experts' votes (either agree or disagree) were considered as achieving consensus.</p> <p>Results</p> <p>Of the 14 originally-proposed patient verbal communication behaviors, the experts modified all but 2, and they added 20 behaviors to the Model in round 1. In round 2, they were presented with 59 behaviors and 14 options to remove specific behaviors for rating. After 3 rounds of rating, the experts retained 22 behaviors. This set included behaviors such as asking questions, expressing preferences, and summarizing information.</p> <p>Conclusion</p> <p>The process identified communication tasks and verbal communication behaviors for patients similar to those outlined for physicians in the Four Habits Model. This represents an important step in building a single model that can be applied to teaching patients and physicians the communication skills associated with improved satisfaction and positive outcomes of care.</p

    Prevalence of 22q11.2 microdeletion in 146 patients with cardiac malformation in a referral hospital of North India

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    <p>Abstract</p> <p>Background</p> <p>The 22q11.2 microdeletion syndrome is a common condition that is associated with cardiac as well as extra-cardiac manifestations. Its prevalence and manifestations from north India has not been reported. This study was designed to determine the prevalence and ability of clinical criteria to predict 22q11.2 microdeletion.</p> <p>Methods</p> <p>A total of 146 cases of cardiac malformation requiring tertiary care at a teaching hospital were prospectively screened for 22q11.2 microdeletion using fluorescence in situ hybridization test. Detailed clinical information was obtained as per guidelines of Tobias, <it>et al </it>(1999).</p> <p>Results</p> <p>Nine out of 146 patients (6.16%) was found to have 22q11.2 microdeletion. All the positive patients showed the presence of extra-cardiac features of 22q11.2 microdeletion syndrome. None of the cases with isolated cardiac defect were positive for microdeletion.</p> <p>Conclusions</p> <p>It seems that 22q11.2 microdeletion syndrome is over-suspected in children with isolated congenital heart defects. Screening for 22q11.2 microdeletion should be considered in those cardiac malformation cases which have extra-cardiac manifestations in the form of facial dysmorphism and hypocalcaemia.</p

    Irradiation of the potential cancer stem cell niches in the adult brain improves progression-free survival of patients with malignant glioma

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    <p>Abstract</p> <p>Background</p> <p>Glioblastoma is the most common brain tumor in adults. The mechanisms leading to glioblastoma are not well understood but animal studies support that inactivation of tumor suppressor genes in neural stem cells (NSC) is required and sufficient to induce glial cancers. This suggests that the NSC niches in the brain may harbor cancer stem cells (CSCs), Thus providing novel therapy targets. We hypothesize that higher radiation doses to these NSC niches improve patient survival by eradicating CSCs.</p> <p>Methods</p> <p>55 adult patients with Grade 3 or Grade 4 glial cancer treated with radiotherapy at UCLA between February of 2003 and May of 2009 were included in this retrospective study. Using radiation planning software and patient radiological records, the SVZ and SGL were reconstructed for each of these patients and dosimetry data for these structures was calculated.</p> <p>Results</p> <p>Using Kaplan-Meier analysis we show that patients whose bilateral subventricular zone (SVZ) received greater than the median SVZ dose (= 43 Gy) had a significant improvement in progression-free survival if compared to patients who received less than the median dose (15.0 vs 7.2 months PFS; P = 0.028). Furthermore, a mean dose >43 Gy to the bilateral SVZ yielded a hazard ratio of 0.73 (P = 0.019). Importantly, similarly analyzing total prescription dose failed to illustrate a statistically significant impact.</p> <p>Conclusions</p> <p>Our study leads us to hypothesize that in glioma targeted radiotherapy of the stem cell niches in the adult brain could yield significant benefits over radiotherapy of the primary tumor mass alone and that damage caused by smaller fractions of radiation maybe less efficiently detected by the DNA repair mechanisms in CSCs.</p
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