Language skills of profoundly deaf children who received cochlear implants under 12 months of age: a preliminary study

Conclusion. This study demonstrated that children who receive a cochlear implant below the age of 2 years obtain higher mean receptive and expressive language scores than children implanted over the age of 2 years. Objective. The purpose of this study was to compare the receptive and expressive language skills of children who received a cochlear implant before 1 year of age to the language skills of children who received an implant between 1 and 3 years of age. Subjects and methods. Standardized language measures, the Reynell Developmental Language Scale (RDLS) and the Preschool Language Scale (PLS), were used to assess the receptive and expressive language skills of 91 children who received an implant before their third birthday. Results. The mean receptive and expressive language scores for the RDLS and the PLS were slightly higher for the children who were implanted below the age of 2 years compared with the children who were implanted over 2 years old. For the PLS, both the receptive and expressive mean standard scores decreased with increasing age at implantation

Medical students’ reactions to an experience-based learning model of clinical education

An experience-based learning (ExBL) model proposes: Medical students learn in workplaces by ‘supported participation’; affects are an important dimension of support; many learning outcomes are affective; supported participation influences students’ professional identity development. The purpose of the study was to check how the model, which is the product of a series of earlier research studies, aligned with students’ experiences, akin to the ‘member checking’ stage of a qualitative research project. In three group discussions, a researcher explained ExBL to 19 junior clinical students, who discussed how it corresponded with their experiences of clinical learning and were given a written précis of it to take away. One to 3 weeks later, they wrote 500-word reflective pieces relating to their subsequent experiences with ExBL. Four researchers conducted a qualitative analysis. Having found many instances of responses ‘resonating’ to the model, the authors systematically identified and coded respondents’ ‘resonances’ to define how they aligned with their experiences. 120 resonances were identified. Seventy (58 %) were positive experiences and 50 (42 %) negative ones. Salient experiences were triggered by the learning environment in 115 instances (96 %) and by learners themselves in 5 instances (4 %), consistent with a strong effect of environment on learning processes. Affective support was apparent in 129 of 203 statements (64 %) of resonances and 118 learning outcomes (58 %) were also affective. ExBL aligns with medical students’ experiences of clinical learning. Subject to further research, these findings suggest ExBL could be used to support the preparation of faculty and students for workplace learning

The Requirement for Viable Platelets in the Coagulation of Heparinized Blood

Activated coagulation times (ACT\u27s) of heparinized blood or plasma samples containing normal platelets were compared with ACT’s of heparinized samples containing non-viable or abnormally functional platelets. The non-viable platelets were prepared by freeze/thawing, and the abnormally functional platelets resulted from the addition of adenosine or adenosine 5\u27-diphosphate (ADP). The ACT’s of the heparinized samples containing treated platelets were considerably longer than the ACT’s performed on samples with untreated platelets. Treated platelets had no effect on unheparinized samples, however. This would indicate that, although platelet factor 3 (PF3) is sufficient to promote clotting of unheparinized blood, viable platelets, in addition, are required for clotting of heparinized blood. A possible hypothesis which explains these findings is as follows: In the unheparinized situation, coagulation factors are activated as clotting takes place. PF3 serves as a surface catalyst, thrombin is generated, and a fibrin clot is formed. The form in which PF3 is available is incidental to clot formation. When heparin is present, however, thrombin is neutralized as fast as it is formed. Quantities sufficient to induce fibrin formation cannot therefore form in the free plasma, and prolonged or infinite clotting times result. In order for coagulation to go to completion, an environment favorable to thrombin generation must be provided. It is probable that, even in heparinized samples, the foreign surface present and the thrombin formed are sufficient to promote platelet aggregation, even though the thrombin levels are too low to directly affect the coagulation system. The interstices of the platelet aggregates provide an environment favorable to thrombin formation. As the platelets aggregate, plasma containing activated clotting factors and heparin is trapped within the platelet clump. Platelet factor 4 (PF4) is released from the platelets and, in the static environment within the clump, is able to completely neutralize the heparin trapped there. This then allows thrombin generation to proceed catalytically. Fibrin formation can now go to completion, both within the platelet aggregate and in the plasmatic atmosphere closely surrounding the clump. The large amounts of thrombin generated overcome the heparin effect, and visible clotting occurs. The implications of an hypothesis such as this may be summarized as follows: 1. Viable platelets are essential to the coagulation of heparinized blood and plasma samples. 2. The varying sensitivities of different individuals to comparable heparin doses may in part reflect the platelet function of those individuals. 3. The fact that variable (and sometimes considerable) numbers of platelets remain in plasma used for activated partial thromboplastin time (APTT) testing implies that the APTT results on such heparinized samples will be correspondingly variable. 4. The APTT, because it is not dependent on the patient\u27s own platelet level, cannot truly reflect that patient\u27s response to heparin. 5. A test such as the activated coagulation time (ACT), which is dependent on the patient\u27s quantitative and qualitative platelet level, reflects more accurately the actual in vivo function of heparin than does the APTT

A systematic review and meta-analysis of mindfulness based interventions and yoga in inflammatory bowel disease

Background: Mindfulness interventions are increasingly used as a part of integrated treatment in inflammatory bowel disease (IBD) but there are limited data and a lack of consensus regarding effectiveness. Objectives: We explored the efficacy of mindfulness interventions compared to treatment as usual (TAU), or other psychotherapeutic interventions, in treating physical and psychosocial symptoms associated with IBD. Methods: We conducted a systematic review and meta-analysis of relevant randomized controlled trials (RCTs). We included a broad range of mindfulness interventions including mindfulness-based interventions and yoga, with no restrictions on date of publication, participants’ age, language or publication type. We searched the following electronic databases: MEDLINE, EMBASE, PsycINFO, CINAHL and WHO ICTRP database. We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines in conducting the review. Results: We included eight studies in the meta-analysis. Mindfulness interventions showed a statistically significant effect on stress in both the short(SMD = −0.48; 95%CI:–0.97, 0.00; P =.05), and long term(SMD = −0.55; 95%CI:-0.78, −0.32;

Comparing the estimates of effect obtained from statistical causal inference methods: An example using bovine respiratory disease in feedlot cattle

The causal effect of an exposure on an outcome of interest in an observational study cannot be estimated directly if the confounding variables are not controlled. Many approaches are available for estimating the causal effect of an exposure. In this manuscript, we demonstrate the advantages associated with using inverse probability weighting (IPW) and doubly robust estimation of the odds ratio in terms of reduced bias. IPW approach can be used to adjust for confounding variables and provide unbiased estimates of the exposure’s causal effect. For cluster-structured data, as is common in animal populations, inverse conditional probability weighting (ICPW) approach can provide a robust estimation of the causal effect. Doubly robust estimation can provide a robust method even when the specification of the model form is uncertain. In this paper, the usage of IPW, ICPW, and doubly robust approaches are illustrated with a subset of data with complete covariates from the Australian-based National Bovine Respiratory Disease Initiative as well as simulated data. We evaluate the causal effect of prior bovine viral diarrhea exposure on bovine respiratory disease in feedlot cattle. The results show that the IPW, ICPW and doubly robust approaches would provide a more accurate estimation of the exposure effect than the traditional outcome regression model, and doubly robust approaches are the most preferable overall

Crotalus atrox venom preconditioning increases plasma fibrinogen and reduces perioperative hemorrhage in a rat model of surgical brain injury.

Perioperative bleeding is a potentially devastating complication in neurosurgical patients, and plasma fibrinogen concentration has been identified as a potential modifiable risk factor for perioperative bleeding. The aim of this study was to evaluate preconditioning with Crotalus atrox venom (Cv-PC) as potential preventive therapy for reducing perioperative hemorrhage in the rodent model of surgical brain injury (SBI). C. atrox venom contains snake venom metalloproteinases that cleave fibrinogen into fibrin split products without inducing clotting. Separately, fibrinogen split products induce fibrinogen production, thereby elevating plasma fibrinogen levels. Thus, the hypothesis was that preconditioning with C. atrox venom will produce fibrinogen spilt products, thereby upregulating fibrinogen levels, ultimately improving perioperative hemostasis during SBI. We observed that Cv-PC SBI animals had significantly reduced intraoperative hemorrhage and postoperative hematoma volumes compared to those of vehicle preconditioned SBI animals. Cv-PC animals were also found to have higher levels of plasma fibrinogen at the time of surgery, with unchanged prothrombin time. Cv-PC studies with fractions of C. atrox venom suggest that snake venom metalloproteinases are largely responsible for the improved hemostasis by Cv-PC. Our findings indicate that Cv-PC increases plasma fibrinogen levels and may provide a promising therapy for reducing perioperative hemorrhage in elective surgeries

Resilience of English vowel perception across regional accent variation

In two categorization experiments using phonotactically legal nonce words, we tested Australian English listeners’ perception of all vowels in their own accent as well as in four less familiar regional varieties of English which differ in how their vowel realizations diverge from Australian English: London, Yorkshire, Newcastle (UK), and New Zealand. Results of Experiment 1 indicated that amongst the vowel differences described in sociophonetic studies and attested in our stimulus materials, only a small subset caused greater perceptual difficulty for Australian listeners than for the corresponding Australian English vowels. We discuss this perceptual tolerance for vowel variation in terms of how perceptual assimilation of phonetic details into abstract vowel categories may contribute to recognizing words across variable pronunciations. Experiment 2 determined whether short-term multi-talker exposure would facilitate accent adaptation, particularly for those vowels that proved more difficult to categorize in Experiment 1. For each accent separately, participants listened to a pre-test passage in the nonce word accent but told by novel talkers before completing the same task as in Experiment 1. In contrast to previous studies showing rapid adaptation to talker-specific variation, our listeners’ subsequent vowel assimilations were largely unaffected by exposure to other talkers’ accent-specific variation

mTORC1 activity is essential for erythropoiesis and B cell lineage commitment

Mechanistic target of rapamycin (mTOR) is a serine/threonine protein kinase that mediates phosphoinositide-3-kinase (PI3K)/AKT signalling. This pathway is involved in a plethora of cellular functions including protein and lipid synthesis, cell migration, cell proliferation and apoptosis. In this study, we proposed to delineate the role of mTORC1 in haemopoietic lineage commitment using knock out (KO) mouse and cell line models. Mx1-cre and Vav-cre expression systems were used to specifically target Raptorfl/fl (mTORC1), either in all tissues upon poly(I:C) inoculation, or specifically in haemopoietic stem cells, respectively. Assessment of the role of mTORC1 during the early stages of development in Vav-cre+Raptorfl/fl mice, revealed that these mice do not survive post birth due to aberrations in erythropoiesis resulting from an arrest in development at the megakaryocyte-erythrocyte progenitor stage. Furthermore, Raptor-deficient mice exhibited a block in B cell lineage commitment. The essential role of Raptor (mTORC1) in erythrocyte and B lineage commitment was confirmed in adult Mx1-cre+Raptorfl/fl mice upon cre-recombinase induction. These studies were supported by results showing that the expression of key lineage commitment regulators, GATA1, GATA2 and PAX5 were dysregulated in the absence of mTORC1-mediated signals. The regulatory role of mTOR during erythropoiesis was confirmed in vitro by demonstrating a reduction of K562 cell differentiation towards RBCs in the presence of established mTOR inhibitors. While mTORC1 plays a fundamental role in promoting RBC development, we showed that mTORC2 has an opposing role, as Rictor-deficient progenitor cells exhibited an elevation in RBC colony formation ex vivo. Collectively, our data demonstrate a critical role played by mTORC1 in regulating the haemopoietic cell lineage commitment