De Lange Syndrome: Report of 20 Cases

Typus Degenerativus Amstelodamensis or Amsterdam dwarfism, a syndrome of unknown etiology characterized by mental retardation, a distinctive face, characteristic hands and feet, defective growth and other minor malformations, was first described by Cornelia de Lange in 1933. Approximately 69 cases, including nine autopsies, have been reported in the literature. In this paper we present a further 20, with illustrations of the syndrome from infancy to puberty (including de Lange''s original three cases). The historical, physical, laboratory and radiographic findings of de Lange''s three patients and our 20 are tabulated. Autopsy findings in one of our patients are reported and the literature is briefly reviewed.Although some observers have recently reported chromosome abnormalities in de Lange''s syndrome, we feel that the diagnosis is made from the history and physical examination and that there are no definitive laboratory aids which can confirm the diagnosis. Chromosome studies in all 20 of our patients were normal and the genetic implications are discussed.     

BACTERIA-ASSIMILABLE ORGANIC COMPOUNDS,PHOSPHATE, AND ENHANCED GROWTH OF BACTERIA-ASSOCIATED BLUE-GREEN ALGAE1

The complexities of algal physiology and nutrition make it likely that diverse and often substantial nutrient limitations will be required to control eutrophication in different situations. In defense of a policy exemplified by the generalization “phosphorus is the primary limiting nutrient in most lakes,” Schindler of the Canadian Freshwater Institute has misquotated the work of Lange. Key points of Lange's conclusions are properly quoted, and the reader is cautioned against an oversimplification of a single approach to algal control.     

Tourette's syndrome: a treatable tic.

Tourette''s syndrome, or Gilles de la Tourette''s disease, is a disorder characterized by involuntary tic-like muscular movements, compulsive behaviour and involuntary vocalization of sounds, words or profanities. It begins in childhood and may persist for life, with a varied pattern and course. Recent studies indicate an organic basis for the disorder, and an abnormality of dopamine or purine metabolism has been suggested. The treatment of choice is haloperidol administration; most patients do well with low or moderate doses for long periods. Because these patients are often mistakenly regarded as anxious, psychoneurotic or hysterical, correct diagnosis is important if they are to be treated appropriately and regarded properly in the home, school and society.     

Philopatry and faithfulness to nest site in Cory's Shearwaters Calonectris diomedea at Selvagem Grande

Mougin, J.-L., Granadeiro, J. P., Jouanin, C. & Roux, F. 1999. Philopatry and faithfulness to nest site in Cory's Shearwaters Calonectris diomedea at Selvagem Grande. Ostrich 70 (3&4): 229–232.

Nearly fledged Cory's Shearwater Calonectris diomedea chicks at Selvagem Grande occasionally desert their nest sites during the night, but generally return before dawn. The temporary use of other nest sites is rare and lasts less than two days. Almost all chicks from Selvagem Grande return to the island for their first breeding attempt; very few breed at islands outside the archipelago. On Selvagem Grande, almost half the males return to their native colony whereas more than 90% of females recruit to other colonies. Inter-colony movements sometimes exceed 1 km, but, if they return to their native colony, both sexes settle within 20 m of their natal site. From the second breeding attempt onwards, most birds of both sexes are faithful to the nest site. On average, less than 20% of birds desert their former nest site each year, with a shift of about 4 m only. Most nest shifts follow a breeding failure or a temporary respite from breeding, and are accompanied by a switch in partners.

Mougin, J.-L., Granadeiro, J. P. Jouanin, C. & Roux, F. 1999. Philopatrie et fidélité au nid chez le Puffin cendré Calonectris diomedea de Selvagem Grande. Ostrich 70 (3&4): 229–232.

Le poussin en fin de croissance du Puffin cendré Calonectris diomedea de Selvagem Grande déserte parfois son nid pendant la nuit, mais y revient généralement avant le jour. L'utilisation temporaire d'un autre site de nid est rare et dure moins de deux jours. Les jeunes adultes nés à Selvagem Grande reviennent presque toujours nicher sur l'île et extrêmement rarement en dehors de l'archipel. A Selvagem Grande, près de la moitié des mâles reviennent à leur colonie de naissance, mais moins de 10% des femelles. Le déplacement est parfois supérieur à 1 km mais, s'ils reviennent à leur colonie natale, les deux sexes s'établissent à moins de 20 m du nid où ils sont nés. A partir de leur deuxième reproduction, les deux sexes sont fidèles à leur nid. Moins de 20% des oiseaux changent de nid d'une année à l'autre, avec un déplacement de 4 m seulement, le plus souvent à la suite d'un échec ou d'une interruption temporaire de la reproduction, ce déplacement étant le plus souvent accompagne d'un changement de partenaire.     

The XXXXY Chromosome Anomaly: Report of Three New Cases and Review of 30 Cases from the Literature

The majority of abnormal sex chromosome complexes in the male have been considered to be variants of Klinefelter''s syndrome but an exception should probably be made in the case of the XXXXY individual who has distinctive phenotypic features. Clinical, radiological and cytological data on three new cases of XXXXY syndrome are presented and 30 cases from the literature are reviewed. In many cases the published clinical and radiological data were supplemented and re-evaluated. Mental retardation, usually severe, was present in all cases. Typical facies was observed in many; clinodactyly of the fifth finger was seen in nearly all.Radiological examination revealed abnormalities in the elbows and wrists in all the 19 personally evaluated cases, and other skeletal anomalies were very frequent. Cryptorchism is very common and absence of Leydig''s cells may differentiate the XXXXY chromosome anomaly from polysomic variants of Klinefelter''s syndrome. The relationship of this syndrome to Klinefelter''s syndrome and to Down''s syndrome is discussed.     

Five cases of cyclical Cushing's syndrome.

Reported cases of cyclical Cushing''s syndrome are rare. Of 14 successive patients with Cushing''s syndrome nine collected sequential urine samples for the estimation of cortisol:creatinine ratio. Five had cyclical Cushing''s syndrome while two had considerable variation in urinary cortisol excretion without a cyclical pattern being established. Two of the five patients with a cyclical syndrome had paradoxical responses to dexamethasone. In only one patient with a cyclical pattern did the cortisol:creatinine ratio fall after treatment with bromocriptine or cyproheptadine, or both. The high incidence of the cyclical form of Cushing''s syndrome has important clinical implications. A high index of suspicion of the syndrome is required in patients with symptoms or signs of Cushing''s syndrome but with normal cortisol values, in patients with fluctuating cortisol values, and in patients with anomalous responses to dexamethasone. Because of possible variations in steroidogenesis the results of drug studies in Cushing''s syndrome must be interpreted cautiously.     

Nephrotic Syndrome in the Elderly

Though the nephrotic syndrome is generally believed to be uncommon in the elderly, patients aged 60 years or more accounted for 25 out of 100 consecutive adult cases. Six (24%) of these had the minimal change lesion, compared with 16% of the younger adults. The incidence of membranous glomerulonephritis was similar in the two age groups, but proliferative glomerulonephritis was more common in the younger (29%) than in the older group (16%). Amyloidosis did not have a higher incidence in the higher age group. Five of the elderly patients with minimal change lesion were treated with prednisone—in four a complete remission from the nephrotic syndrome followed, while the fifth patient''s course is unknown.These results suggest that, when the patient''s other circumstances allow, the nephrotic syndrome in an elderly patient should be investigated and managed as in younger age groups.     

Tourette's syndrome: update.

Tourette''s syndrome is a widely misunderstood chronic disorder that develops in childhood and is usually lifelong. It is characterized by waxing and waning of involuntary motor and phonic tics. The features and differential diagnosis are discussed in this paper. The estimated prevalence rate of Tourette''s syndrome, 0.05%, implies that this disorder is not rare. The reasons for diagnostic confusion are outlined, and the genetic and neurotransmitter features discussed. The management of Tourette''s syndrome has become more effective with the availability of at least two psychoactive drugs, haloperidol and pimozide. Although the cause of this syndrome is thought to be organic, these drugs and their adverse effects are best known to psychiatrists. Psychiatric and multidisciplinary intervention is often necessary because of the frequent association of psychosocial problems, cognitive and learning difficulties, and aggravation of the symptoms by stress. The understanding of Tourette''s syndrome will probably increase significantly with the advent of the newer imaging techniques and the rapid progress of research in the neurosciences.     

口腔微生态与干燥综合征相关性研究进展

干燥综合征是一种炎性细胞侵犯外分泌腺体的慢性自身免疫疾病,口干是其最常见的症状。伴随着干燥综合征患者口腔内微环境的改变,口腔各种微生物之间及微生物与宿主之间的平衡被打破,进而出现口腔微生态失调。口腔微生态失调与自身免疫疾病关系密切,其不仅是疾病所导致的结果,也可能是疾病进一步发展的原因。目前研究认为干燥综合征患者口腔微生态失调与唾液微环境的改变及口腔黏膜免疫受损存在密切的关系,本文对口腔微生态与干燥综合征关系的新近研究进展进行综述。     

Prenatal and postnatal prevalence of Turner's syndrome: a registry study.

OBJECTIVE--To study prevalence of Turner''s syndrome in Denmark and to assess validity of prenatal diagnosis. DESIGN--Study of data on prenatal and postnatal Turner''s syndrome in Danish Cytogenetic Central Register. SUBJECTS--All registered Turner''s syndrome karyotypes (100 prenatal cases and 215 postnatal cases) during 1970-93. MAIN OUTCOME MEASURES--Prevalence of Turner''s syndrome karyotypes among prenatally tested fetuses and Turner''s syndrome among liveborn infants. RESULTS--Among infant girls, prevalence of Turner''s syndrome was 32/100,000. Among female fetuses tested by amniocentesis, prevalence of Turner''s syndrome karyotypes was 176/100,000 (relative risk of syndrome, 6.74 compared with prevalence among untested pregnancies). Among female fetuses tested by chorion villus sampling, prevalence of syndrome karyotypes was 392/100,000 (relative risk, 16.8). We excluded prenatal tests referred because of results of ultrasound scanning: among fetuses tested by amniocentesis revised relative risk was 5.68, while revised relative risk among fetuses tested by chorion villus sampling was 13.3. For 29 fetuses with prenatal diagnosis of possible Turner''s syndrome, pregnancy was allowed to continue and 24 children were live born. Thirteen of these children were karyotyped postnatally, and diagnosis of Turner''s syndrome had to be revised for eight, seven being normal girls and one boy. This gives tentative predictive value of amniocentesis in diagnosing Turner''s syndrome of between 21% and 67%. There was no significant relation between mother''s age and risk of Turner''s syndrome. CONCLUSIONS--Discrepancy between prenatal and postnatal prevalence of Turner''s syndrome challenges specificity of prenatal examination in diagnosing Turner''s syndrome.     

The Diagnosis of Pneumocystis Carinii Pneumonia By Cytologic Evaluation of Papanicolaou and Leishman-Stained Bronchoalveolar Specimens In Patients With the Acquired Immunodeficiency Syndrome

The presence of foamy alveolar casts or flocculent material in Papanicolaou and Leishman-stained smears of bronchoalveolar lavage (BAL) fluid is said to be indicative of infection with Pneumocystis carinii. We have investigated the sensitivity and specificity of this method of diagnosing pneumocystis pneumonia in patients with the acquired immunodeficiency syndrome (AIDS). Patients (n= 114) with diffuse lung infiltrates were submitted to fibreoptic broncoscopy and BAL. Seventy of them were patients with AIDS. the other 44 individuals were not infected by the human immunodeficiency virus (HIV). Pneumocystis carinii organisms were identified on Grocott's methenamine silver (GMS)-stained BAL smears in 30 patients with AIDS. Flocculent material was present in the Papanicolaou and Leishman-stained smears from all of these cases. Conversely, P. carinii were not seen on GMS-stained smears in the remaining 84 individuals with or without AIDS. No flocculent material was observed in Papanicolaou or Leishman-stained smears in these 84 patients. We concluded that the presence of flocculent material in Papanicolaou or Leishman-stained smears of BAL fluid is indicative of P. carinii pneumonia in patients with AIDS. La présence de cylindres alvéolaires spumeux ou de matériel floculé dans les étalements de liquide de lavage bronchoalvéolaire (LBA) colorés selon Papanicolaou ou Leishman est considérée comme symptomatique d'une infection par Pneumocystis carinii. Nous avons étudié la sensibilité et la spécificité de cette méthode de diagnostic de l'infection par Pneumocystis carinii chez des patients atteints de syndrome de déficience immunitaire acquise (SIDA). Cent quatorze malades avec des infiltrats pulmonaires diffus ont subi une fibroscopie bronchique et un lavage broncho-alvéolaire. Soixante dix d'entre eux edtaient atteints de SIDA, 44 n'étaient pas infectés par le Virus de l'Immunodéficience Humaine (VIH). Le Pneumocystis carinii a été identifiié par la coloration de Grocott chez 30 patients atteints de SIDA. Chez ces patients, la présence d'un matériel floculé est constante sur les étalements colorés au Papanicolaou et au Leishman. A l'inverse, Pneumocystis carinii n'a pas été retrouvé chez les 84 autres malades, atteints ou non du SIDA et les étalements de LBA ne contenaient pas de matériel floculé. En conclusion, la présence de matériel floculé dans les étalements de LBA colorés selon Papanicolaou ou Leishmanest associée à une pneumpathie àPneumocystis carinii chez les patients atteints de SIDA. Sensitivität und Spezifität des Nachweises schaumiger oder flockiger Alveolarausgüsse bei Pneumocystis carinii wurden in 114 Fällen diffuser Lungeninfiltrate untersucht. 70 Patienten waren an AIDS erkrankt, 44 weitere waren HIV-negative. In 30 der AIDS-Fälle wurde P. carinii mit der Grocott'schen Färbung nachgewiesen. Die typischen Eiweißniederschläge waren in all diesen Fällen nachweisbar. Umgekehrt ergab die Grocottfärbung in 84 Fällen mit oder ohne AIDS ein negatives Ergebnis. In all diesen Fällen war kein Eiweißniederschlag nachweisbar. Daraus ergibt sich, daß die Eiweißniederschläge in Präparaten, die nach Papanicolaou oder Leishman gefärbt wurden, kennziechned sind für die P. carinii Pneumonie.     

Expression of Insulin-Like Growth Factor-I Receptor and Transferrin Receptor By Breast Cancer Cells In Pleural Effusion Smears

Smear preparations were made from cells harvested from pleural fluid from 90 patients with breast cancer and stained for transferrin receptor (TRFr) and insulin-like growth factor-I receptor (IGF-Ir) using an immunocytochemical technique. the results were correlated with those from 36 benign effusion smears. In malignant smears from the breast cancer cases TRFr was demonstrated in 84.4% of the cellular deposits and IGF-Ir in 91.1%. TRFr was demonstrated in two (11%) of the tuberculous effusion smears and in six (100%) effusions from patients with collagen disease. IGF-Ir was not demonstrated in any of the smears from patients with benign disease. the sensitivity and specificity of TRFr staining were 84.4% and 77.7%, respectively, and for IGF-Ir staining were 91.1% and 100%, respectively. the underlying metabolic changes in the tumour cells which give rise to positive staining with these markers are discussed. Les préparations cytologiques ont été obtenues à partir de cellules recueillies dans le liquide pleural chez 90 patientes ayant un cancer du sein puis ont fait I'objet de techniques immunocytochimiques pour mettre en évidence les récepteurs de la Transferrine (TRF-r) et du facteur de croissance Insulin Like-I (IGF-Ir). Les résultats ont été corrélés avec ceux obtenus sur 36 épanchements bénins. Dans les étalements provenant de patientes traitées pour cancer du sein, TRF-r est positif dans 84,4% des groupements cellulaires et I'IGF-Ir dans 91,1%. Une activité pour le TRF-r est observée dans deux cas (11%) d'epanchements tuberculeux et dans les 6 cas (100Y0) d'épanchement survenant chez des patients atteints de collagénose. Aucune activité IGF-Ir n'est présente dans les cellules des épanchements des patients atteints d'affection bénigne. La sensibilité et la spécificité de I'activité TRF-r sont de 84,4% et de 77% respectivement, celles de I'activité IGF-Ir étant de 91,1% et de 100% respectivement. Les modifications métaboloques sous-jacentes á la positivité en immunocytologie des cellules tumorales avec ces marqueurs sont discutiés. Ausstriche von Pleuraergüssen von 90 Patientinnen mit Mammakarzinom wurden hinsichtlich Tranferrinrezeptoren (TRF-r) und Insulinwachstumsrezeptor (IGF-r) untersucht. 36 benigne Ergüsse dienten als Vergleich. In tumorösen Ergüssen waren TFGr in 84,4% und IGFr in 91,1% nachweisbar. TRFr war ausserdem in 2 (11Y0) der tuberkulösen und 6 (100%) der rheumatischen Ergüsse positiv währen IGFr in keinem der benignen Fälle positiv ausfiel. Sensitivität und Spezifität waren für TRFr 84,4% bzw. 77,7% und IGFr 91,1y0 bzw. 100%. Die metabolischen Veränderungen der Tumorzellen werden diskutiert.     

Le pollen de la tribu des Acalypheae (Acalyphoideae,Euphorbiaceae)

Le pollen de 2/730 genres et de 48/1300 espèces de la tribu des Acalypheae a été étudié en microscopie photonique et électronique à balayage. Les variations des caractères aperturaux et de la disposition des éléments ornementaux permettent de caractériser les onze sous-tribus. Le pollen est généralement colporé et présente presque toujours de petits épaississements de la nexine autour des apertures. Seuls deux genres font exception, Sampantaea p.p. et Dysopsis dont le pollen présente généralement trois simples sillons ectoaperturaux très étroits. Le tectum est perforé et porte en principe des microépines ou microverrues autour des perforations à l'exception de quelques rares espèces où l'ornementation est striée (Micrococca scariosa, Homonoia jaranensis) ou réticulée (Amyrea, Mareya longifolia, Seidelia). Le pollen des Acalypheae se répartit dans deux grands types: 1° le tectum est largement perforé et les grains sont en général plutôt longiaxes; 2° le tectum est à peine microperforé et les grains sont le plus souvent plutôt bréviaxes. Les variations des caractères du pollen: diminution des perforations tectales, réduction considérable de l'ectoaperture et/ou, de l'endoaperture qui peut disparaître même, sont corrélatives de celles de la fleur et du type de pollinisation. Le pollen des Acalypheae présente des rapports évidents avec celui des 3 tribus voisines appartenant aux Acalyphoideae, tandis que ses ressemblances avec celui des Crotonoideae et des Phyllanthoideae ne sont liées qu'à la disposition des éléments libres sur l'exine.

The pollen of 27/30 genera and 48/1300 species of the tribe Acalypheae have been studied by means of L.M. and S.E.M. Variations in the character of the apertures and in the sculpturing elements allow a characterization into eleven subtribes. The pollen is generally colporate and mostly has small nexine thickenings around the apertures. The genera Sampantaea and Dysopsis are the only exceptions to this having pollen with three very narrow ectoapertural simple furrows. The tectum is perforate and has microspines or micropapillae around the perforations, with the exception of some rare species in which the sculpturing is striate (Micrococca scariosa, Homonoia javanensis) or reticulate (Amyrea, Mareya longifolia, Seidelia). The pollen of the Acalypheae belong to two great types: 1° the tectum is widely perforate and the grains are generally longiaxe; 2° the tectum is scarcely microperforate and the grains are often breviaxe. The variations in the pollen characters: a decrease in the tectal perforations, and a great reduction in the ectoaperture and/or the endoaperture which can even disappear, are correlative with those of the flower and its type of pollination. The pollen of the Acalypheae clearly resembles that of the three nearest tribes of the Acalyphoideae. Similarities with the Crotonoideae and the Phyllanthoideae are evident except for the placement of the free elements on the exine.     

Part-Based and Configural Processing of Owner's Face in Dogs

Dogs exhibit characteristic looking patterns when looking at human faces but little is known about what the underlying cognitive mechanisms are and how much these are influenced by individual experience. In Experiment 1, seven dogs were trained in a simultaneous discrimination procedure to assess whether they could discriminate a) the owner''s face parts (eyes, nose or mouth) presented in isolation and b) whole faces where the same parts were covered. Dogs discriminated all the three parts of the owner''s face presented in isolation, but needed fewer sessions to reach the learning criterion for the eyes than for both nose and mouth. Moreover, covering the eyes region significantly disrupted face discriminability compared to the whole face condition while such difference was not found when the nose or mouth was hidden. In Experiment 2, dogs were presented with manipulated images of the owner''s face (inverted, blurred, scrambled, grey-scale) to test the relative contribution of part-based and configural processing in the discrimination of human faces. Furthermore, by comparing the dogs enrolled in the previous experiment and seven ‘naïve’ dogs we examined if the relative contribution of part-based and configural processing was affected by dogs'' experience with the face stimuli. Naïve dogs discriminated the owner only when configural information was provided, whereas expert dogs could discriminate the owner also when part-based processing was necessary. The present study provides the first evidence that dogs can discriminate isolated internal features of a human face and corroborate previous reports of salience of the eyes region for human face processing. Although the reliance on part-perception may be increased by specific experience, our findings suggest that human face discrimination by dogs relies mainly on configural rather than on part-based elaboration.     

Reye's syndrome: assessment of intracranial monitoring.

Direct measurements of arterial blood pressure and intracranial pressure were recorded in 39 patients aged 3.6 months to 5 years 11 months with Reye''s syndrome judged to be stage 2 or beyond. Of 33 patients who survived, 27 made a full recovery and six were severely handicapped. Measurement of cerebral perfusion pressure, which is greatly reduced in the more severe forms of Reye''s syndrome, was a better guide to prognosis and management than intracranial pressure alone. The findings emphasise that maintenance of cerebral perfusion pressure is essential if mortality and morbidity are to be reduced. Intracranial monitoring is mandatory in all but the mildest cases of Reye''s syndrome.     

Autosomal Trisomies and Partial Trisomy Syndromes: (With Presentation of Two Cases of Partial Trisomy for the E Group of Chromosomes)

The establishing of 46 chromosomes as the normal complement in man and the report of the sex chromatin bodies in buccal smears were followed by reports of trisomies and other abnormal patterns of the X and Y chromosomes in Klinefelter''s and Turner''s syndromes. Abnormal autosomal complements were described in mongolism, in the E-trisomy syndrome, the D-trisomy syndrome, in the Sturge-Weber syndrome, Waldenstrom''s macroglobulinemia, benign congenital hypotonia, atrial septal defect and in the schizoid personality. Certain of these conditions, as well as the “oral-facial-digital” syndrome, were also found to exist as partial trisomies. The mechanism of a trisomy is one of non-disjunction and of partial trisomy translocation or insertion. Two cases of the partial trisomy in the E group are described; these are of especial interest because of the familial incidence, longer survival and male sex occurrence, features which are rarely seen in the full E-trisomy syndrome.     

Horse versus machine: battles in the betting shop

Changes in regulation and taxation during the past decade have had a profound effect on the experience of betting in dedicated shops in the United Kingdom. This article explores how betting shop customers and staff in London have responded to the introduction of gambling machines depicting roulette and other casino‐type games in an environment that was traditionally dedicated to betting on horse and dog racing. The rise of machine gambling has been presented as a transition from ‘social’ to ‘asocial’ forms of gambling by researchers working in the UK, Las Vegas, and Australia. Traditional bettors and betting shop staff also present betting and machine play as discrete and value them differently. I show that while some of the experiential qualities of machine play observed elsewhere have been replicated in shops, the differences between traditional betting and machine play are overstated, for structural reasons. Traditional bettors and staff are interested in distinguishing their activities from those of newcomers. Responses to new gambling media in betting shops are socially, as well as experientially, mediated, a crucial insight for the wider study of gambling and gambling regulation.

Résumé

L'évolution de la réglementation et de la taxation des paris a eu depuis une dizaine d'année de profonds effets sur l'expérience des parieurs dans les officines du Royaume‐Uni. Le présent article étudie la réaction des clients et du personnel de bureaux de paris londoniens à l'apparition des machines proposant des jeux de roulette et autres jeux de casino dans un environnement traditionnellement dévolu aux paris sur les courses de chevaux et de chiens. Au Royaume‐Uni, à Las Vegas et en Australie, des chercheurs ont présenté l'essor des machines de jeux comme le passage de formes de jeu « sociales »à d'autres « asociales ». Les parieurs traditionnels et les employés des bureaux de paris considèrent eux aussi les paris et les jeux sur machines comme deux activités distinctes et de valeur différente. L'auteure montre ici qu'une partie des qualités de l'expérience du jeu sur machines observées ailleurs se retrouvent dans les bureaux de paris, mais que les auteurs ont exagéré les différences entre paris traditionnels et jeux sur machines, pour des raisons structurelles. Les parieurs traditionnels et les employés ont intérêt à distinguer leurs activités de celles des nouveaux venus. La réponse aux nouveaux modes de jeu dans les bureaux de paris, médiée socialement mais aussi par l'expérience, est très instructive pour l'étude plus large des jeux de paris et de leur réglementation.     

Dilemma of Dilemmas: How Collective and Individual Perspectives Can Clarify the Size Dilemma in Voluntary Linear Public Goods Dilemmas

Empirical findings on public goods dilemmas indicate an unresolved dilemma: that increasing size—the number of people in the dilemma—sometimes increases, decreases, or does not influence cooperation. We clarify this dilemma by first classifying public goods dilemma properties that specify individual outcomes as individual properties (e.g., Marginal Per Capita Return) and group outcomes as group properties (e.g., public good multiplier), mathematically showing how only one set of properties can remain constant as the dilemma size increases. Underpinning decision-making regarding individual and group properties, we propose that individuals are motivated by both individual and group preferences based on a theory of collective rationality. We use Van Lange''s integrated model of social value orientations to operationalize these preferences as an amalgamation of outcomes for self, outcomes for others, and equality of outcomes. Based on this model, we then predict how the public good''s benefit and size, combined with controlling individual versus group properties, produce different levels of cooperation in public goods dilemmas. A two (low vs. high benefit) by three (2-person baseline vs. 5-person holding constant individual properties vs. 5-person holding constant group properties) factorial experiment (group n = 99; participant n = 390) confirms our hypotheses. The results indicate that when holding constant group properties, size decreases cooperation. Yet when holding constant individual properties, size increases cooperation when benefit is low and does not affect cooperation when benefit is high. Using agent-based simulations of individual and group preferences vis-à-vis the integrative model, we fit a weighted simulation model to the empirical data. This fitted model is sufficient to reproduce the empirical results, but only when both individual (self-interest) and group (other-interest and equality) preference are included. Our research contributes to understanding how people''s motivations and behaviors within public goods dilemmas interact with the properties of the dilemma to lead to collective outcomes.     

Tularemia in Canada with a focus on Saskatchewan

Although rare among humans in Canada, tularemia is often endemic in wildlife. The inhabitants of rural areas are especially likely to be exposed to the causative bacterium, Francisella tularensis, through trapping or through the bites of arthropods. Muskrats have replaced rabbits as the principal source of infection, as illustrated by a familial outbreak of oropharyngeal tularemia in Saskatchewan. In humans the disease has six distinct forms and can be asymptomatic, but it generally comes to medical attention as fever, persistent ulcers and enlarged lymph nodes. Serologic tests will confirm the diagnosis.Bien que la tularémie soit rare chez l''homme au Canada, elle existe souvent à l''état endémique parmi les animaux sauvages. Les habitants des régions rurales sont particuliérement susceptibles d''être exposés à l''agent étiologique, Francisella tularensis, lors du trappage ou par les morsures d''arthropodes. Le rat musqué a maintenant remplacé le lapin comme principale source d''infection, tel que l''illustre une poussée de tularémie oropharyngienne chez une famille de Saskatchewan. Chez l''humain la maladie prend six formes distinctes, et elle peut être asymptomatique, mais elle se présente généralement à l''attention du médecin comme une fièvre accompagnée d''ulcères persistants et d''une tuméfaction ganglionnaire. Les épreuves sérologiques confirment le diagnostic.