Revision of the genus acrochordiceras hyatt, 1877 (Ammonoidea, Middle Triassic): Morphology, biometry, biostratigraphy and intra-specific variability

The family Acrochordiceratidae Arthaber, 1911 ranges in age from latest Spathian to the middle/late Anisian boundary, and it represents a major component of ammonoid faunas during that time. The middle Anisian genus Acrochordiceras Hyatt, 1877 is the most widespread taxon of the family and occurs abundantly worldwide within the low paleolatitude belt. However, there is a profusion of species names available for Acrochordiceras. This excessive diversity at the species level essentially results from the fact that sufficiently large samples were not available, thus leading to a typological approach to its taxonomy. Based on new extensive collections obtained from the Anisian (Middle Triassic) Fossil Hill Member (Star Peak Group, north-west Nevada) for which a high resolution biostratigraphic frame is available, the taxonomy and biostratigraphy of the genus Acrochordiceras Hyatt, 1877 is herein revised with respect to its intra-specific variation. Morphological and biometric studies (c. 550 bedrock-controlled specimens were measured) show that only one species occurs in each stratigraphic level. Continuous ranges of intra-specific variation of studied specimens enable us to synonymize Haydenites Diener, 1907, Silesiacrochordiceras Diener, 1916 and Epacrochordiceras Spath, 1934 with Acrochordiceras Hyatt, 1877. Three stratigraphically successive species are herein recognized in the low paleolatitude middle Anisian faunas from Nevada: A. hatschekii (Diener, 1907), A. hyatti Meek, 1877 and A. carolinae Mojsisovics, 1882. Moreover, an assessment of intra-specific variation of the adult size range does not support recognition of a dimorphic pair (Acrochordiceras and Epacrochordiceras) as previously suggested by other workers (Epacrochordiceras is the compressed and weakly ornamented end-member variant of Acrochordiceras). The successive middle Anisian species of Acrochordiceras form an anagenetic lineage characterized by increasing involution, adult size and intra-specific variation. This taxonomic revision based on new bedrock-controlled collections is thus an important prerequisite before studying the evolution of the group.

Energy-nitrogen balances and protein turnover in small and appropriate for gestational age low birthweight infants.

The aim of the present study was to compare, under the same nursing conditions, the energy-nitrogen balance and the protein turnover in small for gestational age (SGA) and appropriate for gestational age (AGA) low birthweight infants. We compared 8 SGA's (mean +/- s.d.: gestational age 35 +/- 2 weeks, birthweight 1520 +/- 330 g) to 11 AGA premature infants (32 +/- 2 weeks, birthweight 1560 +/- 240 g). When their rate of weight gain was above 15 g/kg/d (17.6 +/- 3.0 and 18.2 +/- 2.6 g/kg/d, mean postnatal age 18 +/- 10 and 20 +/- 9 d respectively) they were studied with respect to their metabolizable energy intake, their energy expenditure, their energy and protein gain and their protein turnover. Energy balance was assessed by the difference between metabolizable energy and energy expenditure as measured by indirect calorimetry. Protein gain was calculated from the amount of retained nitrogen. Protein turnover was estimated by a stable isotope enrichment technique using repeated nasogastric administration of 15N-glycine for 72 h. Although there was no difference in their metabolizable energy intakes (110 +/- 12 versus 108 +/- 11 kcal/kg/d), SGA's had a higher rate of resting energy expenditure (64 +/- 8 versus 57 +/- 8 kcal/kg/d, P less than 0.05). Protein gain and composition of weight gain was very similar in both groups (2.0 +/- 0.4 versus 2.1 +/- 0.4 g protein/kg/d; 3.5 +/- 1.1 versus 3.3 +/- 1.4 g fat/kg/d in SGA's and AGA's respectively). However, the rate of protein synthesis was significantly lower in SGA's (7.7 +/- 1.6 g/kg/d) as compared to AGA's (9.7 +/- 2.8 g/kg/d; P less than 0.05). It is concluded that SGA's have a more efficient protein gain/protein synthesis ratio since for the same weight and protein gains, SGA's show a 20 per cent slower protein turnover. They might therefore tolerate slightly higher protein intakes. Postconceptional age seems to be an important factor in the regulation of protein turnover.

NADPH-diaphorase-positive ganglion cells of the rat adrenal gland: age- and sex-related changes in their number, size, and distribution.

The rat adrenal gland contains ganglion cells able to synthesize nitric oxide (NO). This messenger molecule controls and modulates adrenal secretory activity and blood flow. The present study analyzed the number, size, and distribution of NO-producing adrenal neurons in adulthood and during postnatal development by means of beta-nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry. This method reliably visualizes the enzyme responsible for NO generation. The reactive neurons per adrenal gland were 350-400 in both male and female adult rats. The positive nerve cell bodies were mostly located in the medulla, few being detected within the cortex and the subcapsular region. Dual labeling with anti-microtubule-associated protein 2 antibody, specific for neuronal elements, confirmed this distribution. Anti-microtubule-associated protein 1b antibody identified a subset of NADPH-d-positive neurons, displaying different degrees of maturation according to their position within the adrenal gland. At birth, there were about 220 NADPH-d-labeled neurons per adrenal gland in both sexes. As confirmed by dual immunocytochemical labeling, their great majority was evenly distributed between the cortex and the subcapsular region, the medulla being practically devoid of stained neurons. After birth, the number of adrenal NADPH-d-positive ganglion cells displayed a strong postnatal increase and reached the adult-like distribution after 1-2 months. During the period of increase, there was a transient difference in the numbers of these cells in the two sexes. Thus we present here evidence of plasticity in the number, size, and distribution of NADPH-d-positive adrenal neurons between birth and adulthood; in addition, we describe transient sex-related differences in their number and distribution during the 2nd postnatal week, which are possibly related to the epigenetic action of gonadal hormones during this period.

Parallel changes in genetic diversity and species diversity following a natural disturbance.

We examined the spatial and temporal variation of species diversity and genetic diversity in a metacommunity comprising 16 species of freshwater gastropods. We monitored species abundance at five localities of the Ain river floodplain in southeastern France, over a period of four years. Using 190 AFLP loci, we monitored the genetic diversity of Radix balthica, one of the most abundant gastropod species of the metacommunity, twice during that period. An exceptionally intense drought occurred during the last two years and differentially affected the study sites. This allowed us to test the effect of natural disturbances on changes in both genetic and species diversity. Overall, local (alpha) diversity declined as reflected by lower values of gene diversity H(S) and evenness. In parallel, the among-sites (beta) diversity increased at both the genetic (F(ST)) and species (F(STC)) levels. These results suggest that disturbances can lead to similar changes in genetic and community structure through the combined effects of selective and neutral processes.

Transforming personal experience and emotions through education to cultural diversity: an interplay between unicity and genericity

When subjects studied at school are close to societal discourses and to the students' social identities, when they have high emotional resonance, is it possible to enable the students to distance themselves from their emotions and personal experience, and to conceptualise them? Examining the relation between emotion and learning through the lens of socio-cultural psychology, the aim of our study was to shed light on "secondarisation" processes, that is, processes that transform personal experience and emotions into conceptualised forms of thinking. We analysed 85 video-recorded lessons in education for cultural diversity involving 12 teachers (of primary and secondary schools). Having identified episodes in which emotions were put into words or personal experience was reported, we analysed the use of pronouns (taken as indicators of secondarisation processes) and found a recurrent pattern: "the unicity-genericity routine". We illustrate the functioning of this routine with various excerpts taken from lessons in education for diversity taught in the classes of two teachers in primary school. The results show that the interplay between unicity and genericity works as a discursive resource for the development of secondarisation processes.

Comparisons of serum vitamin d levels, status, and determinants in populations with and without chronic kidney disease not requiring renal dialysis: a 24-hour urine collection population-based study.

OBJECTIVE: Vitamin D deficiency is frequent in the general population and might be even more prevalent among populations with kidney failure. We compared serum vitamin D levels, vitamin D insufficiency/deficiency status, and vitamin D level determinants in populations without chronic kidney disease (CKD) and with CKD not requiring renal dialysis. DESIGN AND METHODS: This was a cross-sectional, multicenter, population-based study conducted from 2010 to 2011. Participants were from 10 centers that represent the geographical and cultural diversity of the Swiss adult population (≥15 years old). INTERVENTION: CKD was defined using estimated glomerular filtration rate and 24-hour albuminuria. Serum vitamin D was measured by liquid chromatography-tandem mass spectrometry. Statistical procedures adapted for survey data were used. MAIN OUTCOME MEASURE: We compared 25-hydroxy-vitamin D (25(OH)D) levels and the prevalence of vitamin D insufficiency/deficiency (serum 25(OH)D < 30 ng/mL) in participants with and without CKD. We tested the interaction of CKD status with 6 a priori defined attributes (age, sex, body mass index, walking activity, serum albumin-corrected calcium, and altitude) on serum vitamin D level or insufficiency/deficiency status taking into account potential confounders. RESULTS: Overall, 11.8% (135 of 1,145) participants had CKD. The 25(OH)D adjusted means (95% confidence interval [CI]) were 23.1 (22.6-23.7) and 23.5 (21.7-25.3) ng/mL in participants without and with CKD, respectively (P = .70). Vitamin D insufficiency or deficiency was frequent among participants without and with CKD (75.3% [95% CI 69.3-81.5] and 69.1 [95% CI 53.9-86.1], P = .054). CKD status did not interact with major determinants of vitamin D, including age, sex, BMI, walking minutes, serum albumin-corrected calcium, or altitude for its effect on vitamin D status or levels. CONCLUSION: Vitamin D concentration and insufficiency/deficiency status are similar in people with or without CKD not requiring renal dialysis.

Complement Factor B Polymorphism and the Phenotype of Early Age-related Macular Degeneration.

Abstract Purpose: Age-related macular degeneration (AMD) has been associated with a number of polymorphisms in genes in the complement pathway. We examined the potential genotype-phenotype correlation of complement factor B (CFB) (R32Q) polymorphisms in Caucasian patients with AMD. Methods: Data from a Central European cohort of 349 patients with early AMD in at least one eye were analyzed for potential associations of the CFB (R32Q/rs641153) polymorphism with phenotypic features of early AMD. Early AMD was classified according to the International Classification and Grading System into predominant drusen size, largest drusen, drusen covered surface, central or ring-like location, peripheral drusen, and pigmentary changes. The potential association with single nucleotide polymorphisms on CFB (R32Q/rs641153) was evaluated for all patients, corrected for age, sex, and the polymorphisms of CFH (Y402H) and ARMS2 (A69S). Results: CFB (R32Q) polymorphisms showed a significant association with smaller drusen size (largest drusen ≤250 µm, p = 0.021, predominant drusen ≤125 µm, p = 0.016), with smaller surface covered by drusen (≤10%; p = 0.02), and with more frequent occurrence of peripheral drusen (p = 0.007). No association was found for pigmentary changes. Conclusions: The CFB (R32Q) polymorphism was associated with AMD characterized by small drusen only, and appeared to be protective of large drusen (OR 0.48/0.45) and of larger drusen covered area (OR 0.34). Furthermore, peripheral drusen were more frequently found (OR 2.27). This result supports the role of complement components and their polymorphisms in drusen formation and may enable a better understanding of AMD pathogenesis.

Emotional and neuroendocrine regulation in very preterm and full-term infants at six months of age

Emotional and neuroendocrine regulation have been shown to be associated. However, results are inconsistent. This paper explores the functioning and relationships between these two systems in 54 healthy preterm and 25 full-term born infants at six months of age. Results showed significant differences between very preterm and full-term children in emotional intensity and regulation, as well as in neuroendocrine regulation. No evidence of an association between neuroendocrine and emotional regulations was found. Results suggest a possible delay in the maturation of the neuroendocrine system as well as in emotional regulation in very preterm infants.