Social learning and the replication process: an experimental investigation

Human cultural traits typically result from a gradual process that has been described as analogous to biological evolution. This observation has led pioneering scholars to draw inspiration from population genetics to develop a rigorous and successful theoretical framework of cultural evolution. Social learning, the mechanism allowing information to be transmitted between individuals, has thus been described as a simple replication mechanism. Although useful, the extent to which this idealization appropriately describes the actual social learning events has not been carefully assessed. Here, we used a specifically developed computer task to evaluate (i) the extent to which social learning leads to the replication of an observed behaviour and (ii) the consequences it has for fitness landscape exploration. Our results show that social learning does not lead to a dichotomous choice between disregarding and replicating social information. Rather, it appeared that individuals combine and transform information coming from multiple sources to produce new solutions. As a consequence, landscape exploration was promoted by the use of social information. These results invite us to rethink the way social learning is commonly modelled and could question the validity of predictions coming from models considering this process as replicative.     

Tinbergen on mirror neurons

Fifty years ago, Niko Tinbergen defined the scope of behavioural biology with his four problems: causation, ontogeny, survival value and evolution. About 20 years ago, there was another highly significant development in behavioural biology—the discovery of mirror neurons (MNs). Here, I use Tinbergen''s original four problems (rather than the list that appears in textbooks) to highlight the differences between two prominent accounts of MNs, the genetic and associative accounts; to suggest that the latter provides the defeasible ‘best explanation’ for current data on the causation and ontogeny of MNs; and to argue that functional analysis, of the kind that Tinbergen identified somewhat misleadingly with studies of ‘survival value’, should be a high priority for future research. In this kind of functional analysis, system-level theories would assign MNs a small, but potentially important, role in the achievement of action understanding—or another social cognitive function—by a production line of interacting component processes. These theories would be tested by experimental intervention in human and non-human animal samples with carefully documented and controlled developmental histories.     

Role of radiation therapy in the multidisciplinary management of Ewing's Sarcoma of bone in pediatric patients: An effective treatment for local control

Background

Radiotherapy (RT) plays an important role in the multidisciplinary management of Ewing''s Sarcoma (ES), especially in unresectable cases.

Aim

Assessment of efficacy of RT in terms of local control in pediatric patients with primary ES of bone.

Materials and methods

Thirty-six patients younger than 17 years old with ES treated with combined RT and chemotherapy with (N = 14) or without (N = 22) prior surgery from 1981 to 2008 were retrospectively reviewed. Since 1995, they were all treated according to the Spanish Society of Pediatric Oncology protocol (55.5% cases). Those patients received vincristine, ifosfamide, doxorubicin and etoposide. The TNM classification was as follows: 17 T1, 18 T2 and 1 T3; 36 N0; 29 M0, 5 M1a and 2 M1b. Analysis was stratified by treatment: definitive RT or pre/postoperative RT.

Results

The 36 patients (21 male; 15 female) had a median age of 10 years (range 2–17 years). Median follow-up of living patients was 105 months. The 2-year local control (LC) rate for all patients was 88%. Five-year LC rates for patients treated with definitive and pre/postoperative RT were 91% and 86%, respectively. Two-year overall survival and disease-free survival rates for all patients were 68% and 66%, respectively. Low phosphatase alkaline levels and local and distant recurrences were significantly predictive of worse prognosis (P = 0.021, P = 0.011, P = 0.007, respectively).

Conclusion

Radiotherapy with and without surgery is a highly effective local treatment option in the multidisciplinary management of ES in pediatric patients.     

Form–meaning links in the development of visual word recognition

Learning to read takes time and it requires explicit instruction. Three decades of research has taught us a good deal about how children learn about the links between orthography and phonology during word reading development. However, we have learned less about the links that children build between orthographic form and meaning. This is surprising given that the goal of reading development must be for children to develop an orthographic system that allows meanings to be accessed quickly, reliably and efficiently from orthography. This review considers whether meaning-related information is used when children read words aloud, and asks what we know about how and when children make connections between form and meaning during the course of reading development.     

Myotonia congenita: novel mutations in CLCN1 gene

Myotonia congenita belongs to the group of non-dystrophic myotonia caused by mutations of CLCN1gene, which encodes human skeletal muscle chloride channel 1. It can be inherited either in autosomal dominant (Thomsen disease) or recessive (Becker disease) forms. Here we have sequenced all 23 exons and exon-intron boundaries of the CLCN1 gene, in a panel of 5 unrelated Chinese patients with myotonia congenita (2 with dominant and 3 with recessive form). In addition, detailed clinical analysis was performed in these patients to summarize their clinical characteristics in relation to their genotypes. Mutational analyses revealed 7 different point mutations. Of these, we have found 3 novel mutations including 2 missense (R47W, V229M), one splicing (IVS19+2T>C), and 4 known mutations (Y261C,G523D, M560T, G859D). Our data expand the spectrum of CLCN1 mutations and provide insights for genotype–phenotype correlations of myotonia congenita in the Chinese population.     

Short term response is predictive of long term response to acetylcholinesterase inhibitors in Alzheimer’s disease: A starting point to explore Bayesian approximation in clinical practice

This study was aimed at identifying, in 203 patients with Alzheimer''s disease followed during long-term treatment with Acetylcholinesterase inhibitors (ChEIs), the predictive factors of the clinical response among cognition (MMSE), functioning (BADL and IADL) measures and age and gender at the baseline (T0). The ANCOVA test showed a significant association between MMSE scores at time T0 and T3, and the variation T9 to T0, T15 to T0 and T21 to T0 of the MMSE scores, using also gender, age and drug as covariates. The significance was higher for the patients affected by mild dementia. Regarding functional activities, a significant relationship was detected, by the ANCOVA test, only between the scores at T3 and the variation T15 to T0 for BADL, and the variation T9 to T0, T15 to T0 for IADL, respectively. Our results confirm, in a real world setting, that ChEIs provide long-term cognitive benefit, which is correlated to, and predictable by, the short-term response (within the third month) as well as the cognitive status (evaluated by means of the MMSE) at the beginning of the treatment. These factors should be the basis of any cost/effectiveness algorithm in health economic decision models.     

Alterations in striatal synaptic transmission are consistent across genetic mouse models of Huntington's disease

Since the identification of the gene responsible for HD (Huntington''s disease), many genetic mouse models have been generated. Each employs a unique approach for delivery of the mutated gene and has a different CAG repeat length and background strain. The resultant diversity in the genetic context and phenotypes of these models has led to extensive debate regarding the relevance of each model to the human disorder. Here, we compare and contrast the striatal synaptic phenotypes of two models of HD, namely the YAC128 mouse, which carries the full-length huntingtin gene on a yeast artificial chromosome, and the CAG140 KI (knock-in) mouse, which carries a human/mouse chimaeric gene that is expressed in the context of the mouse genome, with our previously published data obtained from the R6/2 mouse, which is transgenic for exon 1 mutant huntingtin. We show that striatal MSNs (medium-sized spiny neurons) in YAC128 and CAG140 KI mice have similar electrophysiological phenotypes to that of the R6/2 mouse. These include a progressive increase in membrane input resistance, a reduction in membrane capacitance, a lower frequency of spontaneous excitatory postsynaptic currents and a greater frequency of spontaneous inhibitory postsynaptic currents in a subpopulation of striatal neurons. Thus, despite differences in the context of the inserted gene between these three models of HD, the primary electrophysiological changes observed in striatal MSNs are consistent. The outcomes suggest that the changes are due to the expression of mutant huntingtin and such alterations can be extended to the human condition.     

Identification of patient's requirements in quality management system in health care institutions

AimTo present the solutions implemented in health care institution in the context of identification of patient's requirements, and evaluation of the level of patients’ satisfaction in accordance with the requirements of ISO norm 9001:2008 based on the experience of GPCC.BackgroundThe fundamental mechanisms behind the free market, such as competition, start applying also to the public health sector. Health service providers are gradually realising that patients are actual clients of health care institutions, with physicians, nurses, supporting personnel, registration officers and other staff responding to patients demand for medical and auxiliary services (e.g. exam registration, provision of information).Material and methodsPN-EN ISO 9001:2009 “Quality Management Systems. Requirements”, relevant literature and documentation of quality management system from the GPCC.The review of relevant literature and legal requirements; interpretation of provisions in relation to the functioning of health care institutions.ResultsModel of identification of patient's requirements and satisfaction in accordance with the requirements of ISO 9001:2008 has been elaborated and implemented in the GPCC.ConclusionThe identification of patient's requirements is much more complicated than evaluating the same parameters in manufacturing companies. In the context of medical services one should be aware of the subjectivity of patient's feelings, the psycho-social status and the general state of health during his or her treatment. Therefore, the identification of patient's requirements and satisfaction must be carefully thought out, implemented and regularly improved.     

The neural and cognitive correlates of aimed throwing in chimpanzees: a magnetic resonance image and behavioural study on a unique form of social tool use

It has been hypothesized that neurological adaptations associated with evolutionary selection for throwing may have served as a precursor for the emergence of language and speech in early hominins. Although there are reports of individual differences in aimed throwing in wild and captive apes, to date there has not been a single study that has examined the potential neuroanatomical correlates of this very unique tool-use behaviour in non-human primates. In this study, we examined whether differences in the ratio of white (WM) to grey matter (GM) were evident in the homologue to Broca's area as well as the motor-hand area of the precentral gyrus (termed the KNOB) in chimpanzees that reliably throw compared with those that do not. We found that the proportion of WM in Broca's homologue and the KNOB was significantly higher in subjects that reliably throw compared with those that do not. We further found that asymmetries in WM within both brain regions were larger in the hemisphere contralateral to the chimpanzee's preferred throwing hand. We also found that chimpanzees that reliably throw show significantly better communication abilities than chimpanzees that do not. These results suggest that chimpanzees that have learned to throw have developed greater cortical connectivity between primary motor cortex and the Broca's area homologue. It is suggested that during hominin evolution, after the split between the lines leading to chimpanzees and humans, there was intense selection on increased motor skills associated with throwing and that this potentially formed the foundation for left hemisphere specialization associated with language and speech found in modern humans.     

Temporal expression of mutant LRRK2 in adult rats impairs dopamine reuptake

Parkinson's disease (PD) results from progressive degeneration of dopaminergic neurons. Most PD cases are sporadic, but some have pathogenic mutation in the individual genes. Mutation of the leucine-rich repeat kinase-2 (LRRK2) gene is associated with familial and sporadic PD, as exemplified by G2019S substitution. While constitutive expression of mutant LRRK2 in transgenic mice fails to induce neuron death, transient expression of the disease gene by viral delivery causes a substantial loss of dopaminergic neurons in mice. To further assess LRRK2 pathogenesis, we created inducible transgenic rats expressing human LRRK2 with G2019S substitution. Temporal overexpression of LRRK2(G2019S) in adult rats impaired dopamine reuptake by dopamine transporter (DAT) and thus enhanced locomotor activity, the phenotypes that were not observed in transgenic rats constitutively expressing the gene throughout life time. Reduced DAT binding activity is an early sign of dopaminergic dysfunction in asymptomatic subjects carrying pathogenic mutation in LRRK2. Our transgenic rats recapitulated the initiation process of dopaminergic dysfunction caused by pathogenic mutation in LRRK2. Inducible transgenic approach uncovered phenotypes that may be obscured by developmental compensation in constitutive transgenic rats. Finding in inducible LRRK2 transgenic rats would guide developing effective strategy in transgenic studies: Inducible expression of transgene may induce greater phenotypes than constitutive gene expression, particularly in rodents with short life time.     

Ocular disease in patients with ANCA-positive vasculitis

Anti-neutrophil cytoplasmic antibody (ANCA)-positive vasculitis—the term recently applied to Wegener's granulomatosis—is a rare multi-system inflammation characterized by necrotizing granulomas and vasculitis. We investigated the ocular manifestations of this disease in a group of patients drawn from five inflammatory eye disease clinics across the United States. Of 8,562 persons with ocular inflammation, 59 individuals were diagnosed with ANCA-positive vasculitis; 35 males and 21 females, aged 16 to 96 years, were included in this study. Ocular diagnoses were scleritis (75.0%), uveitis (17.9%), and other ocular inflammatory conditions (33.9%) including peripheral ulcerative keratitis and orbital pseudotumor. Mean duration of ocular disease was 4.6 years. Oral corticosteroids and other systemic immunosuppressive agents were used by 85.7% and 78.5% of patients, respectively. Over time, patients with ANCA-positive vasculitis experienced 2.75-fold higher mortality than other patients with inflammatory eye disease.     

Cost-effectiveness analysis for triple markers serum screening for Down's syndrome in Thai setting

BACKGROUND:

Down''s syndrome is an important congenital chromosomal disorder that can be seen around the world. The antenatal screening for this disorder is an important processing in present obstetrics.

OBJECTIVE:

Due to the concept of first do no harm, the use of noninvasive test is recommended. The triple marker screening test has been introduced for a few years and acceptable for its efficacy.

RESULT:

However, an important concern is on its cost-effectiveness. Here, the author analyze and present the cost-effectiveness of the triple markers serum screening for Down''s syndrome in Thai setting.

CONCLUSION:

According to this work, the cost per effectiveness of triple markers serum screening is slightly lower than standard amniocentesis test.     

What you feel is what you see: inverse dynamics estimation underlies the resistive sensation of a delayed cursor

How our central nervous system (CNS) learns and exploits relationships between force and motion is a fundamental issue in computational neuroscience. While several lines of evidence have suggested that the CNS predicts motion states and signals from motor commands for control and perception (forward dynamics), it remains controversial whether it also performs the ‘inverse’ computation, i.e. the estimation of force from motion (inverse dynamics). Here, we show that the resistive sensation we experience while moving a delayed cursor, perceived purely from the change in visual motion, provides evidence of the inverse computation. To clearly specify the computational process underlying the sensation, we systematically varied the visual feedback and examined its effect on the strength of the sensation. In contrast to the prevailing theory that sensory prediction errors modulate our perception, the sensation did not correlate with errors in cursor motion due to the delay. Instead, it correlated with the amount of exposure to the forward acceleration of the cursor. This indicates that the delayed cursor is interpreted as a mechanical load, and the sensation represents its visually implied reaction force. Namely, the CNS automatically computes inverse dynamics, using visually detected motions, to monitor the dynamic forces involved in our actions.     

Analysis of hemoglobin electrophoresis results and physicians investigative practices in Saudi Arabia

BACKGROUND AND OBJECTIVES:

Riyadh and central province falls in a moderate prevalent zone of hemoglobinopathies in Saudi Arabia. However, it has been observed that the physicians working in Saudi Arabia invariably advise all cases of anemia for hemoglobin electrophoresis (HE). The present work was carried out to study the yield of the HE in Riyadh and the investigative practices of the physicians advising HE.

SETTINGS AND DESIGN:

The study was carried out in the hospitals of King Saud University from 2009 to 2011 in order to assess the yield of HE in referred cases of clinical anemia.

MATERIALS AND METHODS:

A total of 1073 cases divided in two groups of males and females had undergone complete blood count and red blood cell morphology. Cellulose acetate HE was performed and all the positive results were reconfirmed on the high performance liquid chromatography (HPLC). The results were analyzed for the type of hemoglobinopathies. For statistical analysis Statistical Package for Social Sciences 15 version (SPSS Inc., Chicago, IL, USA) was used.

RESULTS:

A total of 405 males and 668 females blood samples were included in the present study. 116 (28.5%) males and 167 (25%) females showed an abnormal pattern on HE. The incidence of beta thalassemia trait was higher in females while sickle cell trait was predominantly seen in males. Red cell indices were reduced considerably in thalassemias, but were unaffected in sickle cell disorders, except those which had concurrent alpha trait. The total yield of HE was 26.6% which was much less than expected.

CONCLUSION:

The physicians are advised to rule out iron deficiency and other common causes of anemia before investigating the cases for hemoglobinopathies, which employs time consuming and expensive tests of HE and HPLC.     

Radiation-induced breast cancer in women with Hodgkin's disease

Aim and background

The aim of this study is to analyze the main clinical and pathologic characteristics of radiation-induced breast carcinomas (BC) following treatment for Hodgkin''s disease (HD) and to identify the risk factors for their induction. To create a mathematical model for the prediction of expected age at which a BC might develop based on the age at treatment for HD.

Materials and methods

Thirty-nine cases of women with BC that developed after treatment for HD in puberty or adolescence were analyzed retrospectively. The median age at initiation of treatment for HD was 12.9 years (9–21). The median age at diagnosis of the second malignancy – breast carcinoma was 32.4 years (22.9–39).

Results

The distribution of patients according to the clinical T stage of breast cancer was as follows: 11 patients with T1 stage BC (28%), 22 with T2 stage (56%) and 6 with stage T3 (16%). Prevalent were tumors localized in the lateral breast quadrants. The observed 5 year survival was 95%.

Conclusion

The risk of solid tumors, especially breast cancer, is high among women with HD disease who were treated with radiotherapy in their childhood. In this article, we propose a specific mathematical age formula which could be used as predictive equation when the age of the treatment for HD is in the range between 9 and 21 years. Systematic screening for breast cancer in these patients would be significantly important for their health and could improve their survival.     

Cologastric fistula with a foreign body in a patient with Crohn's disease

Although the medical management of fistulizing Crohn's disease is improving, a subset of patients does not respond to maximal medical therapy and is referred for surgical consultation. We report a case of Crohn's colitis with an ingested foreign body resulting in a cologastric fistula. The patient underwent segmental colectomy and takedown of the cologastric fistula. At the time of laparotomy, the foreign body was found in the fistulous colonic segment. The presence of an ingested foreign body likely contributed to a rare fistula that was refractory to medical management.