Subjective Beliefs and Inclusion Policies: Evidence from College Admissions

Many countries have introduced preferential admissions to provide new opportunities for talented but disadvantaged students to attend college. Their effectiveness critically depends on students’ perceptions of their incentive schemes. This paper studies this issue by exploiting a randomized preferential admission policy and linked survey-administrative data for 6,054 high-school students in Chile. We document that these students hold overly optimistic beliefs about their admission credentials. We then estimate policy effects on student behavior and outcomes. We find that pre-college effort and achievement fall by 0.1 standard deviations in response to the policy. We develop and structurally estimate a dynamic model of effort, entrance-exam-taking, admissions and enrollments incorporating subjective beliefs. We show that, by distorting effort, belief biases lead overconfident but underprepared students to enter college in response to the policy. We discuss how preferential admission policies can be redesigned to mitigate such distortions and draw closer to achieving their intended objective

STOP: A gamified approach to support obese patients in changing their health habits

Obesity is a challenge for the whole world and it is necessary to find new ways to reduce it and to help people in this situation by facilitating the acquisition of healthy habits to replace unhealthy ones. STOP is a project aimed at facing the challenge of obesity through a digital methodology and through a synergy between experts from the industry and academia. By tracing patients' habits, integrating these data with other data already present in databases and providing personalized paths and feedback the «STop Obesity Platform» can be a valuable help for both patients and Healthcare Professionals. All this is inserted in a gamification frame by the creation of an app that establishes an analogy to the wellknown Dorian Gray mirror with the aim of encouraging the performance of the user or the acquisition of healthy behavior through a stimulating and engaging experience. This paper shows the main objectives of the project, defines the general structure of the app and provides some examples of prototype application

Growth and development of the placenta in the capybara (Hydrochaeris hydrochaeris)

<p>Abstract</p> <p>Background</p> <p>The guinea pig is an attractive model for human pregnancy and placentation, mainly because of its haemomonochorial placental type, but is rather small in size. Therefore, to better understand the impact of body mass, we studied placental development in the capybara which has a body mass around 50 kg and a gestation period of around 150 days. We paid attention to the development of the lobulated arrangement of the placenta, the growth of the labyrinth in the course of gestation, the differentiation of the subplacenta, and the pattern of invasion by extraplacental trophoblast.</p> <p>Methods</p> <p>Material was collected from six animals at pregnancy stages ranging from the late limb bud stage to mid gestation. Methods included latex casts, standard histology, immunohistochemistry for cytokeratin, vimentin, alpha-smooth muscle actin, and proliferating cell nuclear antigen as well as transmission electron microscopy.</p> <p>Results</p> <p>At the limb bud stage, the placenta was a pad of trophoblast covered by a layer of mesoderm from which fetal vessels were beginning to penetrate at folds in the surface. By 70 days, the placenta comprised areas of labyrinth (lobes) separated by interlobular areas. Placental growth resulted predominantly from proliferation of cellular trophoblast situated in nests at the fetal side of the placenta and along internally directed projections on fetal mesenchyme. Additional proliferation was demonstrated for cellular trophoblast within the labyrinth.</p> <p>Already at the limb bud stage, there was a prominent subplacenta comprising cellular and syncytial trophoblast with mesenchyme and associated blood vessels. At 90 days, differentiation was complete and similar to that seen in other hystricognath rodents. Overlap of fetal vessels and maternal blood lacunae was confirmed by latex injection of the vessels. At all stages extraplacental trophoblast was associated with the maternal arterial supply and consisted of cellular trophoblast and syncytial streamers derived from the subplacenta.</p> <p>Conclusion</p> <p>All important characteristics of placental development and organization in the capybara resembled those found in smaller hystricognath rodents including the guinea pig. These features apparently do not dependent on body size. Clearly, placentation in hystricognaths adheres to an extraordinarily stable pattern suggesting they can be used interchangeably as models of human placenta.</p

La membrana vitelina de embriones bovinos, un modelo experimental de interés para estudios proteómicos.Análisis del perfil proteico mediante electroforesis bidimensional

Comunicaciones a congreso

ANALYSIS OF VEGF GENE EXPRESSION IN PLACENTAS OF CLONED BOVINES, PRODUCED IN VITRO AND IN VIVO, BY SEMIQUANTITATIVE RT-PCR)

O sucesso da produção de embriões por fecundação in vitro ou transferência nuclear depende de uma variedade de fatores, dos quais a formação de uma incompleta vascularização placentária representa uma das principais causas de perda gestacional precoce. Neste trabalho, avaliou-se a expressão relativa de Fator de Crescimento Endotélio-vascular (VEGF), um potente agente vasculogênico, em placentas de bovinos clonados por transferência nuclear (NT), produzidos por fecundação in vitro (FIV), ou por monta natural (MN). Verificou-se um decréscimo altamente significativo de expressão de VEGF nas placentas dos animais produzidos in vitro, quando comparados aos animais MN (1,32a; 0,21b; 0,31b, respectivamente para MN, FIV e NT, p<0,05; teste de Duncan), sugerindo haver falha na reprogramação gênica, gerada tanto no sistema de cultivo, quanto na manipulação física de gametas e embriões, alterando o padrão de vascularização placentária e, portanto, ocasionando perdas gestacionais.metas 200

The subplacenta of the red-rumped agouti (Dasyprocta leporina L)

BACKGROUND: Hystricognath rodents have a lobed placenta, comprising labyrinthine exchange areas and interlobular trophoblast. These correspond to the labyrinthine and spongy zones of other rodent placentae. Beneath them, however, is a structure unique to hystricognath rodents called the subplacenta. We here describe the subplacenta of the red-rumped agouti and examine the possible functional correlates of this structure. METHODS: Placentae were collected from early in midgestation to near term of pregnancy and examined by standard histological techniques, immunohistochemistry and transmission electron microscopy. In addition, to study the microvasculature of the subplacenta, vessel casts were inspected by scanning electron microscopy RESULTS: In the subplacenta, lamellae of connective tissue support a layer of mononuclear cytotrophoblast cells. Beneath this is found syncytiotrophoblast. Clusters of multinuclear giant cells occur in the transition zone between the subplacenta and decidua. There are prominent intercellular spaces between the cytotrophoblast cells. The basal membrane of these cells is often close to fetal blood vessels. The syncytiotrophoblast surrounds an extensive system of lacunae. Microvilli project into these lacunae from the plasma membrane of the syncytiotrophoblast. The syncytial cytoplasm contains electron-dense granules. This is probably the amylase-resistant PAS-positive material identified by histochemistry. The subplacenta is supplied entirely from the fetal circulation. Within it the vessels pursue a tortuous course with sinusoidal dilatations and constrictions. CONCLUSION: The functions that have been attributed to the subplacenta include hormone production. Our findings are consistent with this interpretation, but suggest that hormone secretion is directed towards the fetal circulation rather than the maternal tissues

Morphology of the male genital organs and cloaca of Rhea americana americana

As características morfológicas, macroscópicas e microscópicas, dos órgãos genitais masculinos e da cloaca foram analisados em 23 emas, quatro filhotes (duas semanas), sete jovens (de três a oito meses) e doze adultos (três anos), provenientes da Cooperativa Emas do Brasil, RS, e do CEMAS, Mossoró, RN. Os testículos da ema possuem formato alongado e localizam-se na cavidade celomática, na região intra-abdominal dorsal, com comprimento e larguras médias de 7,6±1,2cm e 2,6± 0,7cm nos adultos; 4,5±1,5cm e 0,9±0,4cm nos jovens; e 0,8±0,3cm, e 0,2±0,1cm nos filhotes. O testículo está envolto pela túnica albugínea e seu parênquima possui túbulos seminíferos irregulares, compostos por epitélio espermatogênico e por células de sustentação, e pelo tecido intersticial, com as células endócrinas intersticiais, tecido conjuntivo frouxo e vasos. Nos adultos observaram-se todas as células da linhagem espermatogênica, enquanto nos jovens com 3 meses, os testículos apresentaram túbulos seminíferos com luz reduzidas, espermatogônias e células de sustentação indiferenciadas. Os ductos eferentes possuem um epitélio cúbico ciliado, enquanto no ducto epididimário o epitélio é columnar. O epidídimo apresentou-se alongado e fusiforme junto a margem medial do testículo. O ducto deferentes apresentou trajeto sinuoso nos adultos, retilíneo nos jovens, convoluto na sua porção média, diminuindo seu formato sigmóide em sua porção caudal, próximo à cloaca. O epitélio é pseudoestratificado e reveste a luz irregular nos adultos e circular nos jovens, mantendo proximidade com o ureter. A cloaca dividiu-se em três segmentos: o coprodeu, o urodeo e o proctodeo. No urodeu os ductos deferentes desembocaram em papilas na parede ventro-lateral, próximo a inserção do falo fibroso. O falo é um órgão fibroso linfático, localizado na parede ventral, no assoalho da cloaca, e apresentou duas porções: uma rígida bifurcada e contorcida, e outra simples espiralada e flexível, a qual normalmente esteve invertida. Em exposição forçada, o falo teve 14 cm de comprimento. De forma geral os órgãos reprodutores das emas compartilharam da morfologia de outras aves, principalmente aquelas descritas para os avestruzes.The rhea (Rhea americana americana) is a bird that belongs to the group of the Ratitas, order Rheiforme and family Rheidae. Macroscopic and microscopic morphology of the male genital organ (testes, epididymis, deferent ducts, and phallus) and the cloaca were analyzed in 23 emas, four chicken (2 weeks old), young (3 to 10 months old), and twelve adult ones (3 years old), from Cooperativa Emas do Brasil, RS and from CEMAS, Mossoró, RN. The testis of rhea had elongated shape and were located inside coelomatic cavity, in dorsal region of abdominal cavity, with medium length and width of 7.6±1.2cm and 2.6±0.7cm at adult animals; 4.5±1.5cm and 0.9±0.4cm at young animals; and 0.8±0.3cm, and 0.2±0.1cm at chicken. The testis were recovered by the tunica albuginea and its parenchyma had seminiferous tubules composed by spermatogenic epithelium and by sustentation cells, and also interstitial tissue, with interstitial endocrine cells, connective tissue and vessels. At the adult animals were observed all the cells from spermatogenic lineage, whilst at the youngs with 3 months the seminiferous tubules had a smale lumen with spermatogonia and undifferentiated sustentacular cells. The efferents ductus were composed by a cubic ciliated epithelium, while the epididimydis duct had a columnar epithelium. The epididymis was elongated and fusiform closely to medial testis board. The deferent duct had sinuous stretch at adult animals, rectilineae at young animal, convolute at its medium portion, decreasing its sigmoid shape at caudal portion, next to cloaca. The epithelium was pseudostratified ciliated, irregular lumen at adult animal, and circular at young animal, closely with urether. The cloaca was divided into three segments: coprodeum, urodeum and proctodeum. At urodeum the deferent ducts discharged into papillas at the ventral side wall, next to fibrous phallus's insertion. The phallus was a lymphatic fibrous organ, located at ventral wall, at the cloaca floor, and was composed by two portions: one rigid forked and twisted, and another simple spiraled and flexible, which normally was inverted. In forced exposition, the phallus had 14 cm in length. In a general way the Rhea genital organs shared the morphology from others birds, mainly those described to the ostrich