Settling strategy of stalked echinoderms from the Kaili Biota (middle Cambrian), Guizhou Province,South China

A total of 124 articulated echinoderms, including Sinoeocrinus lui (n = 30), “S. globus” (n = 92), one indeterminate gogiid, and one indeterminate edrioasteroid, from the Kaili Formation (Middle Cambrian), eastern Guizhou, China was examined. Among them, 73% of gogiid echinoderms are preserved attached to skeletal substrates. Suitable skeletal substrates for gogiid holdfasts in the Kaili Biota are organophosphatic brachiopods; large trilobite fragments, including cranidia, free cheeks, thoracic segments, and pygidia; hyoliths; and Scenella shells. The high frequency of “S. globus” attached to organophosphatic brachiopods is due to the high richness of organophosphatic brachiopods rather than a host-specific association in the Kaili Biota. However, the possible discrimination against attachment to small trilobites, such as Pagetia, requires further investigation. Based on 11 hand samples, echinoderm population density (EPD) varies from 0.3 to 4.5 echinoderms per 50 grind points (0.06 to 0.96 echinoderms per cm²), depending on the percent coverage of skeletal debris. Crowding effect is evident when EPD is approximately 0.32 echinoderms per cm² and the skeletal coverage is less than 20%.     

Dumbbell-shaped gogiid clusters: the oldest evidence of secondary tiering for stalked echinoderms

Among 381 specimens of Cambrian stalked echinoderms from eastern Guizhou, China examined, several slabs ( n  = 19) contain either dumbbell-shaped or v-shaped echinoderm clusters. Four slabs of Globoeocrinus globules Zhao, Parsley & Peng, 2008 from the middle-upper part (Cambrian Series 3 portion) of the Kaili Formation are prepared to reveal the attachment sites. Articulated gogiid echinoderms are reported to be attached to both sides of inarticulate (organophosphatic) brachiopods; thus, allowing me to interpret that the larvae of these gogiids were capable of attaching to live benthic brachiopods. This study documents the one of the earliest examples of echinoderms employing secondary tiering, which elevates an organism higher into the benthic boundary layer. Many of the gogiid echinoderm pairs attached to a live brachiopod are similar in size, indicating they were from a single larval spatfall.     

Cambrian spiral-plated echinoderms from Gondwana reveal the earliest pentaradial body plan

Echinoderms are unique among animal phyla in having a pentaradial body plan, and their fossil record provides critical data on how this novel organization came about by revealing intermediate stages. Here, we report a spiral-plated animal from the early Cambrian of Morocco that is the most primitive pentaradial echinoderm yet discovered. It is intermediate between helicoplacoids (a bizarre group of spiral-bodied echinoderms) and crown-group pentaradiate echinoderms. By filling an important gap, this fossil reveals the common pattern that underpins the body plans of the two major echinoderm clades (pelmatozoans and eleutherozoans), showing that differential growth played an important role in their divergence. It also adds to the striking disparity of novel body plans appearing in the Cambrian explosion.     

Deciphering the early evolution of echinoderms with Cambrian fossils

Echinoderms are a major group of invertebrate deuterostomes that have been an important component of marine ecosystems throughout the Phanerozoic. Their fossil record extends back to the Cambrian, when several disparate groups appear in different palaeocontinents at about the same time. Many of these early forms exhibit character combinations that differ radically from extant taxa, and thus their anatomy and phylogeny have long been controversial. Deciphering the earliest evolution of echinoderms therefore requires a detailed understanding of the morphology of Cambrian fossils, as well as the selection of an appropriate root and the identification of homologies for use in phylogenetic analysis. Based on the sister‐group relationships and ontogeny of modern species and new fossil discoveries, we now know that the first echinoderms were bilaterally symmetrical, represented in the fossil record by Ctenoimbricata and some early ctenocystoids. The next branch in echinoderm phylogeny is represented by the asymmetrical cinctans and solutes, with an echinoderm‐type ambulacral system originating in the more crownward of these groups (solutes). The first radial echinoderms are the helicoplacoids, which possess a triradial body plan with three ambulacra radiating from a lateral mouth. Helicocystoids represent the first pentaradial echinoderms and have the mouth facing upwards with five radiating recumbent ambulacra. Pentaradial echinoderms diversified rapidly from the beginning of their history, and the most significant differences between groups are recorded in the construction of the oral area and ambulacra, as well as the nature of their feeding appendages. Taken together, this provides a clear narrative of the early evolution of the echinoderm body plan.     

First report of Gogia (Eocrinoidea, Echinodermata) from the Early-Middle Cambrian of Sonora (Mexico), with biostratigraphical and palaeoecological comments

The blastozoan echinoderm genus Gogia is reported for the first time in the Early and the Middle Cambrian of Mexico. Reports in different members of the section of San José de Gracia (Sonora State, northwestern Mexico) extend the palaeogeographical range of the genus to the South Laurentia, and the stratigraphic range of Gogia granulosa to the whole first half of middle Middle Cambrian. Isolated plates occur in rocks deposited in detrital inner platform and complete specimens, in carbonate outer platform, confirming their ability to live in diverse environments. Their presence in these different environments through the Early-Middle Cambrian on Laurentia agrees with the onshore-offshore expansion of echinoderms during Cambrian.     

Temporal resolution measurement of 128-slice dual source and 320-row area detector computed tomography scanners in helical acquisition mode using the impulse method

PurposeTo analyse the temporal resolution (TR) of modern computed tomography (CT) scanners using the impulse method, and assess the actual maximum TR at respective helical acquisition modes.MethodsTo assess the actual TR of helical acquisition modes of a 128-slice dual source CT (DSCT) scanner and a 320-row area detector CT (ADCT) scanner, we assessed the TRs of various acquisition combinations of a pitch factor (P) and gantry rotation time (R).ResultsThe TR of the helical acquisition modes for the 128-slice DSCT scanner continuously improved with a shorter gantry rotation time and greater pitch factor. However, for the 320-row ADCT scanner, the TR with a pitch factor of <1.0 was almost equal to the gantry rotation time, whereas with pitch factor of >1.0, it was approximately one half of the gantry rotation time. The maximum TR values of single- and dual-source helical acquisition modes for the 128-slice DSCT scanner were 0.138 (R/P = 0.285/1.5) and 0.074 s (R/P = 0.285/3.2), and the maximum TR values of the 64 × 0.5- and 160 × 0.5-mm detector configurations of the helical acquisition modes for the 320-row ADCT scanner were 0.120 (R/P = 0.275/1.375) and 0.195 s (R/P = 0.3/0.6), respectively.ConclusionBecause the TR of a CT scanner is not accurately depicted in the specifications of the individual scanner, appropriate acquisition conditions should be determined based on the actual TR measurement.     

Cytology and embryology of the pompom weed,Campuloclinium macrocephalum (Eupatorieae,Asteraceae)

Campuloclinium macrocephalum (Less.) DC. is a perennial herb widely distributed in the New World, but introduced to South Africa, where it is commonly called “pompom weed”. This species is considered one of the most important weeds from Brazil and it has been included among the plant invaders of South Africa. Results of the meiotic and embryological analyses of six populations of C. macrocephalum are reported in this paper. The microsporogenesis analysis revealed five triploid (2n = 3x = 30) and one diploid (2n = 2x = 20) populations with a basic chromosome number x = 10. The diploid specimens showed regular meiotic behavior, but the triploid plants presented irregular chromosome pairing which result in the formation of univalents, bivalents and trivalents at diakinesis. In consequence, laggard chromosomes, unbalanced nuclei and micronuclei were observed in subsequent phases of meiosis. The embryological analysis showed that the triploid specimens of C. macrocephalum have embryo sac development from a nucellar cell (apospory), which indicates that these specimens are apomictic. Almost all cases of apomixis found in tribe Eupatorieae are diplosporous apomixis. Campuloclinium macrocephalum constitutes the second species of the tribe and the first of the genus with apospory as reproductive system. The aposporous apomixis combined with the presence of xylopodium would be two important factors responsible for the invasiveness of C. macrocephalum.     

First evidence for Cambrian glaciation provided by sections in Avalonian New Brunswick and Ireland: Additional data for Avalon–Gondwana separation by the earliest Palaeozoic

The first evidence for Cambrian glaciation is provided by two successions on the Avalon microcontinent. The middle lowest Cambrian (middle Terreneuvian Series and Fortunian Stage–Stage 2 boundary interval) has an incised sequence boundary overlain by a fluvial lowstand facies and higher, olive green, marine mudstone on Hanford Brook, southern New Brunswick. This succession in the lower Mystery Lake Member of the Chapel Island Formation may be related to melting of an ice sheet in Avalon. The evidence for this interpretation is a muddy diamictite with outsized (up to 10 cm in diameter), Proterozoic marble and basalt clasts that penetrated overlying laminae in the marine mudstone. That eustatic rise was associated with the mudstone deposition is suggested by an approximately coeval rise that deposited sediments with Watsonella crosbyi Zone fossils 650 km away in Avalonian eastern Newfoundland. A sea-level rise within the Watsonella crosbyi Chron, at ca. 535 Ma, may correspond to a unnamed negative ¹³C excursion younger than the basal Cambrian excursion (BACE) and the ZHUCE excursion in Stage 2 of the upper Terreneuvian Series. Cambrian dropstones are now also recognized on the northern (Gander) margin of Avalon in continental slope–rise sedimentary rocks in southeast Ireland. Although their age (Early–Middle Cambrian) is poorly constrained, dropstones in the Booley Bay Formation provide additional evidence for Cambrian glaciation on the Avalon microcontinent. Besides providing the first evidence of Cambrian glaciation, these dropstone deposits emphasize that Avalon was not part of or even latitudinally close to the terminal Ediacaran–Cambrian, tropical carbonate platform successions of West Gondwana.     

Early life conditions,reproductive and sexuality-related life history outcomes among human males: A systematic review and meta-analysis

In order to investigate the association between early life conditions and reproductive and sexuality-related life history outcomes among men, we conducted a meta-analysis that compiled the results of 198 articles. A total of 331 effect sizes drawn from 573 samples were included. The meta-analysis revealed that low family socioeconomic status was associated with early sexual debut (r = 0.07), early first birth (r = 0.14), and early marriage (r = 0.03). There was no significant association between family socioeconomic status and pubertal timing or number of sexual partners. Parental absence was associated with early sexual debut (r = ? 0.12), greater number of sexual partners (r = ? 0.19), early first birth (r = ? 0.14), and early marriage (r = ? 0.13). There was no significant association between parental absence and pubertal timing. Small body size before puberty was associated with delayed pubertal timing (r = ? 0.10). There was no significant association between adult body size and number of offspring, and between body size at birth and pubertal timing. Small adult body size, greater number of siblings, and older parents were associated with non-heterosexual orientation (rs = 0.12, 0.03, and 0.03 respectively). Factors such as sampling procedure, data collection method, and age cut-off used to measure family structure change influenced the association between some predictors (e.g., family socioeconomic status) and outcomes (e.g., first birth). The findings are discussed in relation to the utility of life history theory for understanding human male reproductive and sexuality-related outcomes.     

Embryos,polyps and medusae of the Early Cambrian scyphozoan Olivooides

The Early Cambrian organism Olivooides is known from both embryonic and post-embryonic stages and, consequently, it has the potential to yield vital insights into developmental evolution at the time that animal body plans were established. However, this potential can only be realized if the phylogenetic relationships of Olivooides can be constrained. The affinities of Olivooides have proved controversial because of the lack of knowledge of the internal anatomy and the limited range of developmental stages known. Here, we describe rare embryonic specimens in which internal anatomical features are preserved. We also present a fuller sequence of fossilized developmental stages of Olivooides, including associated specimens that we interpret as budding ephyrae (juvenile medusae), all of which display a clear pentaradial symmetry. Within the framework of a cnidarian interpretation, the new data serve to pinpoint the phylogenetic position of Olivooides to the scyphozoan stem group. Hypotheses about scalidophoran or echinoderm affinities of Olivooides can be rejected.     

A new eocrinoid fauna (Cambrian Series 2) from Guizhou Province,South China

A new eocrinoid locality of the Balang Formation (Cambrian Series 2) near Kaili City is reported. The fauna is associated with index trilobites, such as Redlichia (Pteroredlichia) murakamii Resser and Endo in Kobayashi, 1935 and Arthricocephalus chauveaui Bergeron, 1899, that are common in the Balang Biota (Cambrian Series 2) but absent in the younger Kaili Biota (Cambrian Series 3). This new locality contains a new eocrinoid fauna (n = 22) that is different from Guizhoueocrinus yui Zhao, Parsley and Peng, 2007a in bearing a smaller theca, a shorter stalk, and a robust attachment disk; thus, a taxon Globoeocrinus zhaoyuanlongensis n. sp. is proposed.     

A negative carbon isotope excursion defines the boundary from Cambrian Series 2 to Cambrian Series 3 on the Yangtze Platform,South China

A globally recorded negative carbon isotope excursion characterizes the transition from Cambrian Series 2 to Cambrian Series 3. This transition is also well exposed in sedimentary successions on the Yangtze Platform, and the Wuliu–Zengjiayan section, Guizhou Province, South China has been proposed as a potential Global Stratotype Section and Point (GSSP) for this boundary. Here, we report δ¹³C_carb values for the Jianshan and the Wuliu–Zengjiayan sections. Both sections display a progressive decrease in δ¹³C from values around + 3‰ upwards in stratigraphy to a pronounced δ¹³C minimum with values as low as ? 6.9‰ at the proposed boundary level, and a return to δ¹³C values between 0 and + 1‰ in the upper part of the sections. The δ¹³C minimum is thought to be caused by a transgressive event, flooding the shelf area with ¹³C depleted basinal anoxic bottom water. Our δ¹³C data are in good agreement with carbon isotope profiles recorded elsewhere. These define the so called ROECE event (Redlichiid–Oleneliid Extinction Carbon Isotope Excursion, cf. Zhu et al., 2006, 2007) and may reflect the perturbation of the global carbon cycle during the Cambrian Series 2 to Cambrian Series 3 transition.     

Thermal energetics of the New-Guinean moss-forest rat (Rattus niobe) in comparison with other tropical murid rodents

The thermal energetics of rodents from cool, wet tropical highlands are poorly known. Metabolic rate, body temperature and thermal conductance were measured in the moss-forest rat, Rattus niobe (Rodentia), a small murid endemic to the highlands of New Guinea. These data were evaluated in the context of the variation observed in the genus Rattus and among tropical murids. In 7 adult R. niobe, basal metabolic rate (BMR) averaged 53.6±6.6 mL O₂ h⁻¹, or 103% of the value predicted for a body mass of 42.3±5.8 g. Compared to other species of Rattus, R. niobe combines a low body temperature (35.5±0.6 °C) and a moderately low minimal wet thermal conductance c_min (5.88±0.7 mL O₂ h⁻¹ °C⁻¹, 95% of predicted) with a small size, all of which lead to reduced energy expenditure in a constantly cool environment. The correlations of mean annual rainfall and temperature, altitude and body mass with BMR, body temperature and c_min were analyzed comparatively among tropical Muridae. Neither BMR, nor c_min or body temperature correlated with ambient temperature or altitude. Some of the factors which promote high BMR in higher latitude habitats, such as seasonal exposure to very low temperature and short reproductive season, are lacking in wet montane tropical forests. BMR increased with rainfall, confirming a pattern observed among other assemblages of mammals. This correlation was due to the low BMR of several desert adapted murids, while R. niobe and other species from wet habitats had a moderate BMR.     

Occurrence of human-pathogenic Enterocytozoon bieneusi,Giardia duodenalis and Cryptosporidium genotypes in laboratory macaques in Guangxi,China

Captive nonhuman primates have been identified as common hosts of Enterocytozoon bieneusi, Giardia duodenalis, Cryptosporidium hominis, and Cyclospora spp., thus are potential reservoirs of some enteric parasites in humans. However, few studies have examined the source and human-infective potential of enteric parasites in laboratory nonhuman primates. In the present work, 205 fecal specimens were collected from three groups of captive Macaca fascicularis kept in different densities in a laboratory animal facility in Guangxi, China, and examined by PCR for E. bieneusi, G. duodenalis, Cryptosporidium spp., and Cyclospora spp. The infection rates of E. bieneusi and G. duodenalis were 11.3% and 1.2% in Group 1 (young animals kept individually; n = 168), 72.2% and 11.1% in Group 2 (young animals kept in groups; n = 18), and 31.6% and 5.3% in Group 3 (adults kept in groups; n = 19), respectively. Sequence analysis of PCR products showed the presence of five E. bieneusi genotypes, with genotype D (in 16/36 genotyped specimens) and a new genotype (in 15/36 genotyped specimens) as the dominant genotypes. All five E. bieneusi genotypes belonged to the zoonotic group (Group 1). The G. duodenalis genotypes (assemblages AII and B) in five specimens and C. hominis subtype (IdA14) in one specimen were also known human-pathogens, although the Cyclospora seen in one animal appeared to be unique to macaque monkeys. The higher infection rate in younger animals reared in groups and common occurrence of zoonotic genotypes indicated that human-pathogenic E. bieneusi could be transmitted efficiently in captive nonhuman primates, and group-housing was a risk factor for transmission of zoonotic pathogens in young nonhuman primates in research facilities.     

Phylomineralogy of the Coralline red algae: Correlation of skeletal mineralogy with molecular phylogeny

The coralline algae in the orders Corallinales and Sporolithales (subclass Corallinophycidae), with their high degree of mineralogical variability, pose a challenge to projections regarding mineralogy and response to ocean acidification. Here we relate skeletal carbonate mineralogy to a well-established phylogenetic framework and draw inferences about the effects of future changes in sea-water chemistry on these calcified red algae. A collection of 191 coralline algal specimens from New Zealand, representing 13 genera and 28 species, included members of three families: Corallinaceae, Hapalidiaceae, and Sporolithaceae. While most skeletal specimens were entirely calcitic (range: 73–100 wt.% calcite, mean 97 wt.% calcite, std dev = 5, n = 172), a considerable number contained at least some aragonite. Mg in calcite ranged from 10.5 to 16.4 wt.% MgCO₃, with a mean of 13.1 wt.% MgCO₃ (std dev = 1.1, n = 172). The genera Mesophyllum and Lithophyllum were especially variable. Growth habit, too, was related to mineralogy: geniculate coralline algae do not generally contain any aragonite. Mg content varied among coralline families: the Corallinaceae had the highest Mg content, followed by the Sporolithaceae and the Hapalidiaceae. Despite the significant differences among families, variation and overlap prevent the use of carbonate mineralogy as a taxonomic character in the coralline algae. Latitude (as a proxy for water temperature) had only a slight relationship to Mg content in coralline algae, contrary to trends observed in other biomineralising taxa. Temperate magnesium calcites, like those produced by coralline algae, are particularly vulnerable to ocean acidification. Changes in biomineralisation or species distribution may occur over the next few decades, particularly to species producing high-Mg calcite, as pH and CO₂ dynamics change in coastal temperate oceans.     

Growth,intake, diet digestibility,and nitrogen use in three hair sheep breeds fed alfalfa hay

Pen feeding and metabolism trials were conducted to determine intake, diet digestibility and nitrogen (N) use in three hair sheep breeds with differing growth potential offered an alfalfa hay diet. For pen feeding, 24 6-mo-old wether lambs, equally representing the Barbados Blackbelly, Katahdin, and St. Croix breeds, were paired by breed, placed in 12 enclosed cement-floor pens (2.5 m × 3.5 m), and offered chopped alfalfa (Medicago sativa L.; 17.6% CP, 50.4% NDF, and 36.4% ADF) ad libitum. Lambs were allowed a 14-d adaptation period to pens and diets, and remained on trial for 56 d. Starting body weight (BW) was different (P < 0.05) among breeds (Barbados Blackbelly: 23.8 kg; Katahdin: 36.5 kg; St. Croix: 29.1 kg). Daily gain was not different (P < 0.10) between Katahdin (131 g/d) and St. Croix (117 g/d), but both were higher (P < 0.05) than Barbados Blackbelly (87 g/d). Daily dry matter hay intake was similar among breeds (107–109 g/kg BW^0.75), and feed to gain ratio ranged from 8.7 in St. Croix and 9.1 in Katahdin to 10.5 in Barbados Blackbelly, but was not different (P > 0.10) among breeds. Six lambs per breed were used in the metabolism trial. Total DMI was greater (P < 0.01) for Katahdin (1196 g/d) than St. Croix (907 g/d) and Barbados Blackbelly (858 g/d), but was not different (P > 0.10) adjusted for body weight (mean: 71 g/kg BW^0.75). Coefficients of apparent digestibility for DM (P < 0.06), OM (P < 0.06), N (P < 0.05), NDF (P < 0.08), and ADF (P < 0.08) were higher for Katahdin compared to Barbados Blackbelly with St. Croix intermediate. Intake of N (P < 0.01), feces N (P < 0.08), urine N (P < 0.01), absorbed N (P < 0.01), and retained N (P < 0.05) also were greater for Katahdin compared to St. Croix and Barbados Blackbelly. Blood glucose, urea-N, and creatinine were not different (P > 0.10) among breeds. Breeds differed in their growth performance in line with breed mature size, and differences were observed in N digestibility and absorption.     

The Quételet index revisited in children and adults

BackgroundThe body mass index (BMI) is based on the original concept that body weight increases as a function of height squared. As an indicator of obesity the modern BMI assumption postulates that adiposity also increases as a function of height in states of positive energy balance.ObjectiveTo evaluate the BMI concept across different adiposity magnitudes, in both children and adults.MethodsWe studied 975 individuals who underwent anthropometric evaluation: 474 children and 501 adults. Tetrapolar bioimpedance analysis was used to assess body fat and lean mass.ResultsBMI significantly correlated with percentage of body fat (%BF; children: r = 0.893; adults: r = 0.878) and with total fat mass (children: r = 0.967; adults: r = 0.953). In children, body weight, fat mass, %BF and waist circumference progressively increased as a function of height squared. In adults body weight increased as a function of height squared, but %BF actually decreased with increasing height both in men (r = −0.406; p < 0.001) and women (r = −0.413; p < 0.001). Most of the BMI variance in adults was explained by a positive correlation of total lean mass with height squared (r² = 0.709), and by a negative correlation of BMI with total fat mass (r = −0.193).ConclusionsBody weight increases as a function of height squared. However, adiposity progressively increases as a function of height only in children. BMI is not an ideal indicator of obesity in adults since it is significantly influenced by the lean mass, even in obese individuals.     

Treatment with pioglitazone is associated with decreased preprandial ghrelin levels: A randomized clinical trial

The effects of metformin and pioglitazone on ghrelin, a physiologic regulator of appetite and food intake, have not been clearly established. In a randomized clinical trial, we randomly assigned 60 type 2 diabetic patients to either metformin (Group A; n = 30) or pioglitazone (Group B; n = 30) treatment groups. The groups were similar in their baseline characteristics. A standard fasting 75 g oral glucose tolerance test was performed at time zero before starting metformin or pioglitazone, and 3 months later. After 3 months of treatment, pioglitazone, but not metformin, was significantly associated with weight gain. Both groups experienced a significant reduction in fasting plasma glucose (p < 0.01), hemoglobin A1c (p < 0.01 in Group A and p < 0.05 in Group B), and insulin resistance (p < 0.01). The effect of metformin on preprandial ghrelin and its response to glucose challenge was not significant, while the pioglitazone group had a significant reduction in preprandial ghrelin levels after treatment (p < 0.05). The effect of pioglitazone on ghrelin was independent of changes in body weight, body mass index, glucose control, insulin resistance, and plasma insulin. In conclusion, treatment with pioglitazone is associated with a decrease in preprandial ghrelin levels and therefore, the weight gain and increased food intake related to pioglitazone use cannot be explained by its effects on ghrelin. The effect of pioglitazone on ghrelin is independent of changes in body weight, body mass index, plasma insulin, insulin resistance, or glucose control.