Portrait of His Majesty the King

There are major contextural differences between the two bird forms carved on the pillars of the Acosta reconstruction of the Quetzalpapalotl courtyard. The frontal bird on the west side and its distinctive border decorations suggest differences of meaning from the profile bird representation which occupies the remaining three sides. Séjourné's argument that the carvings represent two views of the same bird is refuted in the light of careful visual comparisons of the forms and ornithological examination. Other iconographic research on bird meaning in the context of Teotihuacán culture is discussed followed by an interpretation of the meaning of the two bird images.     

Pharmacological characteristics of three silent giant neurons, v-LPSN, v-1-VOrN and v-VLN, identified on the ventral surface in the left parietal and the visceral ganglia of the suboesophageal ganglia of an African giant snail (Achatina fulica Férussac)

Three giant neurons, named v-LPSN, v-1-VOrN and v-VLN, were identified on the ventral surface of the left parietal ganglion and the visceral ganglion in the suboesophageal ganglia of an African giant snail (Achatina fulica Férussac). They lacked the spontaneous spike discharges in the normal state. The pharmacological features of the three neurons, in relation to the principal common neurotransmitter substances and their derivatives were examined. The v-LPSN (ventral-left parietal silent neuron) (diameter: about 130 microns) is situated in the left parietal ganglion close to the visceral ganglion. The neuron was excited by histamine (the minimum effective concentration [MEC]: 3 X 10(-4) M) and inhibited slightly by acetylcholine (Ach) and its related substances. The v-1-VOrN (ventral-left-visceral oral neuron) (diameter: about 130 microns) is situated in the left and oral part of the visceral ganglion. The neuron was inhibited markedly by dopamine (DA) (MEC: 3 X 10(-4) M) and slightly by Ach and its related substances. No substance producing a marked excitation of the neuron has been found yet. The v-VLN (ventral-visceral large neuron) (diameter: about 300 microns) is found in the centre of the visceral ganglion. The neuron was excited by L-norepinephrine (MEC: 10(-4) M), DL-octopamine (MEC: 2 X 10(-4) M), 5-hydroxytryptamine (MEC: 10(-4) M) and beta-hydroxy-L-glutamic acid (MEC: 10(-4) M) and inhibited by DA (MEC: 10(-4) M), GABA (MEC: 3 X 10(-5) M) and Ach (MEC: 10(-4) M). L-Epinephrine showed varied effects (MEC: 10(-4) M), which were either excitatory or inhibitory.     

Diseases of maize in the wet lowland tropics and the collapse of the Classic Maya civilization

The Classic Maya civilization was centered in lowlands of the Petén in northern Guatemala, and collapsed mysteriously in the ninth century AD. Abandoned were rich agricultural lands carved without metal tools out of a tropical rain forest, lands that had been farmed with increasing intensity for six to sixteen centuries. The Maya evidently resettled in highlands to the south or in less productive dry lowlands to the north. No reoccupation occurred of the Petén farms, homes or ceremonial centers until their discovery in the past two centuries. Sustained crop failure of maize (Zen mavs L.) due to an epidemic of the planthopper-borne virus, maize mosaic virus (MMV), is proposed as a primary contributing cause of the collapse. Major diseases and pests of maize in the tropics are assessed for their relative significance in and near the Petén vs. the highlands, and the viruses are highlighted. Maize mosaic virus is a devastating virus disease transmitted by the corn planthopper,Peregrinus maidis, an insect restricted to tropic lowlands. Maize and teosinte are its only definitively known hosts. Thus the disease has been serious only where maize is grown more-or-less continuously through the year in wet or irrigated tropics (e.g., Caribbean Islands, Venezuela, Hawaii, Tanzania, Australia). It is reported here for southern Mexico and the Petén of Guatemala. Resistance in maize occurs only in one known form, the gene Mv. that confers a high level resistance but not immunity. Resistance data are presented for 63 of the 67 races of maize thought to have evolved in the Northern Hemisphere. The Mv gene is shown to occur in all seven of the races of maize evolved in the Caribbean, but in none of the primitive Mexican or Central American races. It is proposed that maize mosaic virus originated in northern South America at or about the time maize was brought into the Caribbean by the Arawak around the time of Christ. The sympatric origin or selection in maize of the Mv resistance mutant in this region is assumed to have led to its incorporation in all seven Caribbean maize races. It is conjectured that viruliferous leafhoppers were blown from the Caribbean into the Petén around the eighth century allowing the disease to become epidemic in susceptible maize races such as Nal-Tel and Tepecintle, grown by the Petén Maya. Sustained failure of maize production due to MMV would have characterized areas of intensive maize cultivation, particularly where it was year-round. The disease would have been less severe in areas with a long dry season, as to the north of Yucatán and it would not have occurred in the highland areas to the south and west, areas to which surviving Maya presumably migrated.     

Enhancing learning through optimal sequencing of web-based and manikin simulators to teach shock physiology in the medical curriculum

The Association of American Medical Colleges has encouraged educators to investigate proper linkage of simulation experiences with medical curricula. The authors aimed to determine if student knowledge and satisfaction differ between participation in web-based and manikin simulations for learning shock physiology and treatment and to determine if a specific training sequencing had a differential effect on learning. All 40 second-year medical students participated in a randomized, counterbalanced study with two interventions: group 1 (n = 20) participated in a web-based simulation followed by a manikin simulation and group 2 (n = 20) participated in reverse order. Knowledge and attitudes were documented. Mixed-model ANOVA indicated a significant main effect of time (F(1,38) = 18.6, P < 0.001, η(p)(2) = 0.33). Group 1 scored significantly higher on quiz 2 (81.5%) than on quiz 1 (74.3%, t(19) = 3.9, P = 0.001), for an observed difference of 7.2% (95% confidence interval: 3.3, 11.0). Mean quiz scores of group 2 did not differ significantly (quiz 1: 77.0% and quiz 2: 79.7%). There was no significant main effect of group or a group by time interaction effect. Students rated the simulations as equally effective in teaching shock physiology (P = 0.88); however, the manikin simulation was regarded as more effective in teaching shock treatment (P < 0.001). Most students (73.7%) preferred the manikin simulation. The two simulations may be of similar efficacy for educating students on the physiology of shock; however, the data suggest improved learning when web-based simulation precedes manikin use. This finding warrants further study.     

Les colorants dans l’art pariétal et mobilier paléolithique de La Garma (Cantabrie,Espagne)

La Garma Cave is an Upper Palaeolithic site located ca 15 km from Santander (Cantabria, Spain). The lower gallery, which is accessible thanks to two wells, keeps paintings on the walls and numerous objects laying on the floor, objects made in bone or antler which are carved, engraved and painted. The analysis of more than 50 samples taken from the walls or the objects (37 red, 11 black, five yellow, two brown, one purple) takes part in the global project of the “chaîne opératoire” comprehension of the prehistoric painting activity. The analysis is aimed also to understand the organisation of La Garma cave, looking for the various steps of the decoration of the different rooms. The results bring to light the modulated realisation of the wall paintings: few figures were painted rapidly without any specific intention, the majority, on the other hand, were realised after a complex preparation of the painting matter with the use of specific paint pots.     

Teratogenic antibody internalization by rat visceral yolk-sac endoderm in vitro: an ultrastructural colloidal gold tracer study

Previous work from our laboratory has demonstrated that specific rabbit immunoglobulins G (IgG) against a glycoprotein antigen of rat kidney proximal tubule or a cross-reacting visceral yolk-sac endodermal cell antigen will induce abnormal embryonic development when they are injected into pregnant rats during the period of organogenesis. It has been proposed that these antibodies may induce embryopathy by interfering with functions of the visceral yolk-sac placenta, an important organ providing nutrients to the embryo at this stage of development. In order to gain some insight into the underlying pathogenic mechanism(s) in which specific teratogenic IgG may interfere with visceral yolk-sac functions, we examined the uptake of these teratogenic IgG by the visceral yolk-sac endodermal cells at the electron microscopic level. The results demonstrated that teratogenic rabbit IgG specifically localized on the fuzzy coat of the external apical cell membrane of the visceral yolk-sac endoderm at the intermicrovillous region. Within 5 min, the IgG were rapidly internalized via coated pits and micropinocytic vesicles. Within 30 min, an increasing proportion of gold particles appeared within uncoated vesicles or vacuoles of various sizes; most of the gold particles were in close proximity to the inner membranous lining of the vesicles. Similar findings were observed after 1- or 2-hr incubation. After 24- to 48-hr culture, however, the gold particles appeared to have dissociated from the inner surface of the vesicle membrane.(ABSTRACT TRUNCATED AT 250 WORDS)     

Within species support for the expensive tissue hypothesis: a negative association between brain size and visceral fat storage in females of the Pacific seaweed pipefish

The brain is one of the most energetically expensive organs in the vertebrate body. Consequently, the high cost of brain development and maintenance is predicted to constrain adaptive brain size evolution (the expensive tissue hypothesis, ETH). Here, we test the ETH in a teleost fish with predominant female mating competition (reversed sex roles) and male pregnancy, the pacific seaweed pipefish Syngnathus schlegeli. The relative size of the brain and other energetically expensive organs (kidney, liver, heart, gut, visceral fat, and ovary/testis) was compared among three groups: pregnant males, nonpregnant males and egg producing females. Brood size in pregnant males was unrelated to brain size or the size of any other organ, whereas positive relationships were found between ovary size, kidney size, and liver size in females. Moreover, we found that the size of energetically expensive organs (brain, heart, gut, kidney, and liver) as well as the amount of visceral fat did not differ between pregnant and nonpregnant males. However, we found marked differences in relative size of the expensive organs between sexes. Females had larger liver and kidney than males, whereas males stored more visceral fat than females. Furthermore, in females we found a negative correlation between brain size and the amount of visceral fat, whereas in males, a positive trend between brain size and both liver and heart size was found. These results suggest that, while the majority of variation in the size of various expensive organs in this species likely reflects that individuals in good condition can afford to allocate resources to several organs, the cost of the expensive brain was visible in the visceral fat content of females, possibly due to the high costs associated with female egg production.     

Proposition d’une nouvelle biozonation par ammonites de l’Albien du Bassin andin (Pérou)

The study of the ammonite fauna of the Albian formations allows a major revision of its biostratigraphic frame in northern and central Peru. A carving in ammonite biozones is proposed for the Inca, Chulec and Pariatambo Formations and the Pulluicana group. The Lower Albian is represented by the Nicholsoni Biozone (subdivided into the umbilicostatus, and nicholsoni biohorizons, followed by an interval subzone) and by the Raimondii Biozone (carved in three subzones: Haasi, Raimondii – itself subdivided into the ebrayi and alternum biohorizons – and Mathewsi, including the pseudolyelli biohorizon). The Middle Albian is characterised by the Carbonarium Biozone, carved in the Ulrichi and Carbonarium Subzones. The base of Upper Albian is represented by the Cristatum Subzone.     

Linoleic acid kinetics and conversion to arachidonic acid in the pregnant and fetal baboon.

Linoleic acid plasma kinetics in pregnant baboons and its conversion to long chain polyunsaturates (LCP) in fetal organs is characterized over a 29-day period using stable isotope tracers. Pregnant baboons consumed an LCP-free diet and received [U-13C]linoleic acid (18:2*) in their third trimester of gestation. In maternal plasma, 18:2* dropped to near baseline by 14 days post-dose, while labeled arachidonic acid (20:4*) plateaued at 10 days at about 70% of total labeled fatty acids. After 2;-5 days, total tracer fatty acids decreased in visceral organs, but increased in the fetal brain. Maximal fetal incorporation of 18:2* was 1;-2 days post-dose; thereafter it dropped while 20:4* increased reciprocally. Labeled 20:4 replaced 18:2* in neural tissues by 5 days post-dose. In liver, kidney, and lung, 20:4* became dominant by 12 days, but in heart the crossover was >29 days. Fetal brain 20:4* plateaued by 21 days at 0. 025% of dose, while fetal liver 20:4* was constant from 1 to 29 days at 0.006% of dose. Under these dietary conditions we estimate that the fetus derives about 50% its 20:4 requirement from conversion of dietary 18:2, with the balance from maternal stores, and conclude that 1) fetal organs accumulate 18:2 within a day of a maternal dose and convert much of it to 20:4 within weeks, 2) modest dietary 18:2 levels may support fetal brain requirements for 20:4, and 3) the brain retains n;-6 fatty acids uniquely compared with major visceral organs.     

Experimental tremor produced by ventromedial tegmental lesion in monkeys. Neuroanatomical study

Destruction of the ventromedial tegmentum (VMT) of the midbrain in the monkey has been known to produce tremor similar to that seen in Parkinson's disease. A neuroanatomical study by a silver impregnation method was conducted on 5 monkeys, demonstrating the characteristic flexed posture with hypokinesia of the contralateral upper limb (reliable premonitory sign of tremor) following destruction of VMT with a histologically proven lesion site. The results are summarized as follows: (1) the tractus nigrostriatus, (2) tractus tegmentalis centralis, (3) ascending fiber bundles going to the thalamus (particularly VL.X and VPLo) and (4) descending fibers leading to the bilateral substantia nigra constitute the bulk, if not all, of those neural tracts which pass through the VMT. This, along with the proven existence of fibers projecting to the thalamic nuclei, is thought to account for the rhythmic burst discharges recorded from the VL or Vim nucleus in the monkey and in Parkinson's disease patients. The present experimental study also seems to provide an additional anatomical basis for the concept that the tractus tectonigralis is involved in the mechanism of development of kinésie paradoxale.     

Spontaneous malformations in JW-NIBS rabbits

The frequency of spontaneous anomalies among JW-NIBS rabbits in our laboratory is reported. The study was based on 1217 live fetuses obtained from 185 of an origin sample of 195 pregnant females; the remaining 10 (5.1%) aborted. Seven (0.57%) of the fetuses had the following external anomalies: multiple anomalies with craniofacial anomalies and thoraco-, gastroschisis (3 cases), microcephaly with open eyelids and microstomia (1), microphthalmia (1), anury (1) and brachyury (1). Among 1213 fetuses, 2 (0.16%) had abdominal visceral anomalies: agenesis of gall bladder and hypoplasia of the ovary were each found in one animal. Head and thoracic visceral anomalies were found in 6 (1.73%) of 347 fetuses, and skeletal anomalies in 6 (0.69%) of 867 fetuses. 4.03% of fetuses had 13 ribs.     

Unnoticed swallowing of a unilateral removable partial denture

doi: 10.1111/j.1741‐2358.2011.00621.x Unnoticed swallowing of a unilateral removable partial denture Objective: This paper presents a case report about an unnoticed swallowing of a partial denture impacted in the esophagus in a 74‐year old man without serious complications. Background data: Dental prostheses (removable/fixed dental prostheses or fragments of dentures) appear to constitute a significant proportion of swallowed of impacted foreign bodies in the orolaryngopharynx. Conclusion: This case emphazises that is advisable to contraindicate this type of unilateral removable partial denture to replace teeth as temporary or definitive dental prosthesis.     

Urogenital schistosomiasis during pregnancy is associated with low birth weight delivery: analysis of a prospective cohort of pregnant women and their offspring in Gabon

An estimated 40 million women of childbearing age suffer from schistosomiasis. Animal models indicate a deleterious effect of maternal schistosomiasis on pregnancy outcomes. To date there is a lack of epidemiological evidence evaluating schistosomiasis-related morbidity in pregnancy. This study was designed to describe the impact of urogenital schistosomiasis on pregnancy outcomes in a highly endemic region of central Africa. Pregnant women attending antenatal clinics in Fougamou and Lambaréné, Gabon, were consecutively screened for the presence of Schistosoma haematobium eggs in diurnal urine samples. Maternal and newborn characteristics assessed at delivery were compared between infected and uninfected mothers. The impact of maternal schistosomiasis on low birth weight and preterm delivery was assessed using logistic regression analysis. Urogenital schistosomiasis was diagnosed in 103 (9%) of 1115 pregnant women. Maternal age was inversely associated with the prevalence of urogenital schistosomiasis, with a higher burden amongst nulliparous women. Low birth weight was more common amongst infants of S. haematobium-infected mothers. This association was unaffected by controlling for demographic characteristics, gestational age and Plasmodium infection status (adjusted Odds Ratio 1.93; 95% confidence interval: 1.08–3.42). Other risk factors associated with low birth weight delivery were underweight mothers (adjusted Odds Ratio 2.34; 95% confidence interval: 1.12–4.92), peripheral or placental Plasmodium falciparum infection (adjusted Odds Ratio 2.04; 95% confidence interval: 1.18–3.53) and preterm birth (adjusted Odds Ratio 3.12; 95% confidence interval: 1.97–4.96). Preterm delivery was not associated with S. haematobium infection (adjusted Odds Ratio 1.07 95% confidence interval: 0.57–1.98). In conclusion, this study indicates that pregnant women with urogenital schistosomiasis are at an increased risk for low birth weight deliveries. Further studies evaluating targeted treatment and prevention programmes for urogenital schistosomiasis in pregnant women and their impact on delivery outcomes are warranted.     

Accretion of visceral fat and hepatic insulin resistance in pregnant rats

Insulin resistance (IR) is a hallmark of pregnancy. Because increased visceral fat (VF) is associated with IR in nonpregnant states, we reasoned that fat accretion might be important in the development of IR during pregnancy. To determine whether VF depots increase in pregnancy and whether VF contributes to IR, we studied three groups of 6-mo-old female Sprague-Dawley rats: 1) nonpregnant sham-operated rats (Nonpreg; n = 6), 2) pregnant sham-operated rats (Preg; n = 6), and 3) pregnant rats in which VF was surgically removed 1 mo before mating (PVF-; n = 6). VF doubled by day 19 of pregnancy (Nonpreg 5.1 +/- 0.3, Preg 10.0 +/- 1.0 g, P < 0.01), and PVF- had similar amounts of VF compared with Nonpreg (PVF- 4.6 +/- 0.8 g). Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp in late gestation in chronically catheterized unstressed rats. Glucose IR (mg.kg(-1).min(-1)) was highest in Nonpreg (19.4 +/- 2.0), lowest in Preg (11.1 +/- 1.4), and intermediate in PVF- (14.7 +/- 0.6; P < 0.001 between all groups). During the clamp, Nonpreg had greater hepatic insulin sensitivity than Preg [hepatic glucose production (HGP): Nonpreg 4.5 +/- 1.3, Preg 9.3 +/- 0.5 mg.kg(-1).min(-1); P < 0.001]. With decreased VF, hepatic insulin sensitivity was similar to nonpregnant levels in PVF- (HGP 4.9 +/- 0.8 mg.kg(-1).min(-1)). Both pregnant groups had lower peripheral glucose uptake compared with Nonpreg. In parallel with hepatic insulin sensitivity, hepatic triglyceride content was increased in pregnancy (Nonpreg 1.9 +/- 0.4 vs. Preg 3.2 +/- 0.3 mg/g) and decreased with removal of VF (PVF- 1.3 +/- 0.4 mg/g; P < 0.05). Accretion of visceral fat is an important component in the development of hepatic IR in pregnancy, and accumulation of hepatic triglycerides is a mechanism by which visceral fat may modulate insulin action in pregnancy.     

Development and validity of a universal empirical equation to predict skin surface temperature on thermal manikins

Clothing evaporative resistance is an important input in thermal comfort models. Thermal manikin tests give the most accurate and reliable evaporative resistance values for clothing. The calculation methods of clothing evaporative resistance require the sweating skin surface temperature (i.e., options 1 and 2). However, prevailing calculation methods of clothing evaporative resistance (i.e., options 3 and 4) are based on the controlled nude manikin surface temperature due to the sensory measurement difficulty. In order to overcome the difficulty of attaching temperature sensors to the wet skin surface and to enhance the calculation accuracy on evaporative resistance, we conducted an intensive skin study on a thermal manikin ‘Tore’. The relationship among the nude manikin surface temperature, the total heat loss and the wet skin surface temperature in three ambient conditions was investigated. A universal empirical equation to predict the wet skin surface temperature of a sweating thermal manikin was developed and validated on the manikin dressed in six different clothing ensembles. The skin surface temperature prediction equation in an ambient temperature range between 25.0 and 34.0 °C is T_sk=34.0–0.0132HL. It is demonstrated that the universal empirical equation is a good alternative to predicting the wet skin surface temperature and facilitates calculating the evaporative resistance of permeable clothing ensembles. Further studies on the validation of the empirical equation on different thermal manikins are needed however.     

Familial Clustering of Abdominal Visceral Fat and Total Fat Mass: The Québec Family Study

The evidence for common familial factors underlying total fat mass (estimated from underwater weighing) and abdominal visceral fat (assessed from CT scan) was examined in families participating in phase 2 of the Québec Family Study (QFS) using a bivariate familial correlation model. Previous QFS investigations suggest that both genetic (major and polygenic) and familial environmental factors influence each phenotype, accounting for between 55% to 71% of the phenotypic variance in fat mass, and between 55% to 72% for abdominal visceral fat The current study suggests that the bivariate familial effect ranges from 29% to 50%. This pattern suggests that there may be common familial determinants for abdominal visceral fat and total fat mass, as well as additional familial factors which are specific to each. The relatively high spouse cross-trait correlations usually suggest that a large percent of the bivariate familial effect may be environmental in origin. However, if mating is not random, then the spouse resemblance may reflect either genetic or environmental causes, depending on the source [i.e., through similar genes or cohabitation (environmental) effects]. Finally, there are significant sex differences in the magnitude of the familial cross-trait correlations involving parents, but not offspring, suggesting complex generation (i.e., age) and sex effects. For example, genes may turn on or off as a function of age and sex, and/or there may be an accumulation over time of effects due to the environment which may vary by sex. Whether the common familial factors are genetic (major and/or polygenic), environmental, or some combination of both, and whether the familial expression depends on sex and/or age warrants further investigation using more complex models.