bluuebunny/crossref_metadata_2025 huggingface dataset:
Acoustic and Morphological Differentiation in the FrogAllobates femoralis: Relationships with the Upper Madeira River and Other Potential Geological Barriers
Authors: Simões Pedro Ivo , Lima Albertina P. , Magnusson William E. , Hödl Walter , Amézquita Adolfo
Published: April 2008

We studied patterns of call acoustics and external morphological differentiation in populations of the dart‐poison frogAllobates femoralisoccurring in forested areas along a 250‐km stretch of the upper Madeira River, Brazil. Multivariate analyses of variance using principal components representing shared acoustic and morphological parameters distinguished three groups in relation to call structure and external morphology: (1) populations belonging to a two‐note call morphotype; (2) populations with four‐note calls inhabiting the left riverbank; and (3) populations with four‐note calls inhabiting the right riverbank. Our results report a case of Amazonian anuran diversity hidden by current taxonomy and provide evidence for the upper Madeira River being a boundary between distinct populations ofA. femoralis, and suggest a new taxonomic interpretation for these groups. Samples that did not fit into the general differentiation pattern and the existence of a well‐defined contact zone between two morphotypes on the left riverbank indicate that mechanisms complementary to river‐barrier hypotheses are necessary to explain the phenotypic differentiation between populations. Our study shows that at least one anuran species shows congruence between population differentiation and separation by a large Amazonian river, as documented for birds and mammals. Conservation efforts should not consider the taxon now known asA. femoralisas a homogeneous entity. There is much within‐taxon variability, which can be probably explained partly by the existence of cryptic species, partly by geological barriers and part of which currently has no obvious explanation.
Multivariate Analyses of Water Chemistry: Surface and Ground Water Interactions
Authors: Woocay Arturo , Walton John
Published: April 2008

Multivariate statistical methods (MSMs) applied to ground water chemistry provide valuable insight into the main hydrochemical species, hydrochemical processes, and water flowpaths important to ground water evolution. The MSMs of principal component factor analysis (FA) and k‐means cluster analysis (CA) were sequentially applied to major ion chemistry from 211 different ground water–sampling locations in the Amargosa Desert. The FA reduces the number of variables describing the system and finds relationships between major ions. The CA of the reduced system produced objective hydrochemical facies, which are independent of, but in good agreement with, lithological data. The derived factors and hydrochemical facies are innovatively presented on biplots, revealing composition of hydrochemical processes and facies, and overlaid on a digital elevation model, displaying flowpaths and interactions with geologic and topographic features in the region. In particular, a distinct ground water chemical signature is observed beneath and surrounding the extended flowpath of Fortymile Wash, presenting some contradiction to contemporary water levels along with potential interaction with a fault line. The signature surrounding the ephemeral Fortymile Wash is believed to represent the relic of water that infiltrated during past pluvial periods when the amount of runoff in the wash was significantly larger than during the current drier period. This hypothesis and aforementioned analyses are supported by the examination of available chloride, oxygen‐18, hydrogen‐2, and carbon‐14 data from the region.
Delineation of Regional Arid Karstic Aquifers: An Integrative Data Approach
Authors: Wolaver Brad D. , Sharp John M. , Rodriguez Juan M. , Ibarra Flores Juan Carlos
Published: April 2008

This research integrates data procedures for the delineation of regional ground water flow systems in arid karstic basins with sparse hydrogeologic data using surface topography data, geologic mapping, permeability data, chloride concentrations of ground water and precipitation, and measured discharge data. This integrative data analysis framework can be applied to evaluate arid karstic aquifer systems globally. The accurate delineation of ground water recharge areas in developing aquifer systems with sparse hydrogeologic data is essential for their effective long‐term development and management. We illustrate the use of this approach in the Cuatrociénegas Basin (CCB) of Mexico. Aquifers are characterized using geographic information systems for ground water catchment delineation, an analytical model for interbasin flow evaluation, a chloride balance approach for recharge estimation, and a water budget for mapping contributing catchments over a large region. The test study area includes the CCB of Coahuila, Mexico, a UNESCO World Biosphere Reserve containing more than 500 springs that support ground water–dependent ecosystems with more than 70 endemic organisms and irrigated agriculture. We define recharge areas that contribute local and regional ground water discharge to springs and the regional flow system. Results show that the regional aquifer system follows a topographic gradient that during past pluvial periods may have linked the Río Nazas and the Río Aguanaval of the Sierra Madre Occidental to the Río Grande via the CCB and other large, currently dry, upgradient lakes.
3HO/Sikh Dharma of the Western Hemisphere: The ‘Forgotten’ New Religious Movement?
Authors: Jakobsh Doris
Published: April 2008

This article will give a general overview of a Sikh movement that originated in the 1960s with an immigrant from India known as Harbhajan Singh, a Khatri Sikh. His initial aim was to teach yoga in Canada, but the job he was promised did not materialize, and thus it was that he turned his attention towards California. In Los Angeles, he took on a new name, Yogi Bhajan, and soon surrounded himself with eager students. An ashram was built soon thereafter and by 1969 his ‘Healthy, Happy, Holy’ group was incorporated as a tax exempt organization. Although Bhajan was from a traditional Sikh family, he increasingly focused on Kundalini Yoga and Tantra in his teaching and practices. However, Sikh teachings were also incorporated into his message, a message that was largely directed towards a white, middle‐class, counter‐culture audience. Needless to say, the Punjabi Sikh community has had a mixed reaction to the ‘Gora’ (white) converts, particularly with regard to the accretions and modifications to the Sikh traditions, upheld by Bhajan and his followers. This article will address aspects of 3HO (or Sikh Dharma in the Western Hemisphere) in its current manifestation that resembles characteristics of new religious movements, particularly its claims to universality and purity within its own manifestation of ‘true’ Sikh identity.
Performance Criticism of the Hebrew Bible
Authors: Giles Terry , Doan William
Published: April 2008

Performance criticism is a critical methodology that is based upon the premise that select portions of the Hebrew Bible (and Christian New Testament as well) are literary variations of originally oral compositions that were read or recited before live audiences. Those readings and recitations were performative in nature and understanding the performative dynamics at work in the material, being read or recited, can yield fresh insights into the meaning of the material. Performance criticism applies concepts commonly used in performative studies to the Hebrew Bible in an effort to better understand the conventions and structures enabling communication.
Social Scientific Approach to the Hebrew Bible
Authors: Sneed Mark
Published: April 2008

In 1979, Cyril Rodd, biblical scholar, predicted the end of social scientific criticism of the Old Testament because its theories cannot be tested. He was wrong. It is currently thriving. It is interdisciplinary: either a biblical scholar who does research in the social sciences who then applies this to the Bible or a social scientist who does research on a biblical text and then applies it to the Bible. Social scientific approaches help fill in gaps that other ways of interpreting the Bible leave behind. For example, have you ever wondered why Cain was not punished with death for killing his brother? The Old Testament commands the death penalty for any murderer. Traditional interpretation emphasizes God's grace because he repented. But an anthropological perspective explains it as due to the fact that Cain was Abel's brother, his kin, and his death would have ended the family line of Adam and Eve. In less developed countries, kinship is very important, and some form of punishments like the death penalty would do more harm than good. Other forms of punishment might include payment, exile, and substitution.
Structural Effects on the Electronic Absorption Properties of 5,6‐Dihydroxyindole Oligomers: The Potential of an Integrated Experimental and DFT Approach to Model Eumelanin Optical Properties†
Authors: D’Ischia Marco , Crescenzi Orlando , Pezzella Alessandro , Arzillo Marianna , Panzella Lucia , Napolitano Alessandra , Barone Vincenzo
Published: April 2008

Elucidation of the relationships between structural features and UV–visible absorption properties of 5,6‐dihydroxyindole oligomers is an essential step towards an understanding of the unique optical properties of eumelanins. Herein, we report the first combined experimental and density functional theory (DFT) investigation of the 5,6‐dihydroxyindole oligomers so far isolated. 2,2′‐Biindolyl 2 and the 2,4′‐biindolyl 3 absorb at longer wavelengths relative to 2,7′‐biindolyl 4 and their spectra were well predicted by DFT analysis. The absorption bands of 2,4′:2′,4′′‐ and 2,4′:2′,7′′‐triindolyls 5 and 6 also fall at different wavelengths and can be interpreted by DFT simulations as being due to a combination of two main separate transitions. Tetramer 7, in which two 2,4′‐biindolyl units are linked through a 2,3′‐connection, exhibits a broad chromophore extending over the entire UV range without well defined absorption maxima. Within the dimer–tetramer range examined, three key points emerge: (1) an increase in oligomer chain length does not result in any regular and predictable bathochromic shift; (2) a marked broadening of the absorption bands occurs when going from the monomer to the tetramer structure; and (3) the mode of coupling of the indole units is a crucial, hitherto unrecognized, structural parameter affecting the electronic absorption properties of 5,6‐dihydroxyindole oligomers. It is concluded that use of experimentally characterized oligomeric scaffolds as a basis for DFT calculations is a most promising approach to building reliable structural models for studies of eumelanins optical properties.
Synthesis and Excited‐state Photodynamics of a Chlorin–Bacteriochlorin Dyad—Through‐space Versus Through‐bond Energy Transfer in Tetrapyrrole Arrays
Authors: Muthiah Chinnasamy , Kee Hooi Ling , Diers James R. , Fan Dazhong , Ptaszek Marcin , Bocian David F. , Holten Dewey , Lindsey Jonathan S.
Published: April 2008

Understanding energy transfer among hydroporphyrins is of fundamental interest and essential for a wide variety of photochemical applications. Toward this goal, a synthetic free base ethynylphenylchlorin has been coupled with a synthetic free base bromobacteriochlorin to give a phenylethyne‐linked chlorin–bacteriochlorin dyad (FbC‐pe‐FbB). The chlorin and bacteriochlorin are each stable toward adventitious oxidation because of the presence of a geminal dimethyl group in each reduced pyrrole ring. A combination of static and transient optical spectroscopic studies indicate that excitation into the Qy band of the chlorin constituent (675 nm) of FbC‐pe‐FbB in toluene results in rapid energy transfer to the bacteriochlorin constituent with a rate of ∼(5 ps)−1 and efficiency of >99%. The excited bacteriochlorin resulting from the energy‐transfer process in FbC‐pe‐FbB has essentially the same fluorescence characteristics as an isolated monomeric reference compound, namely a narrow (12 nm fwhm) fluorescence emission band at 760 nm and a long‐lived (5.4 ns) Qy excited state that exhibits a significant fluorescence quantum yield (Φf = 0.19). Förster calculations are consistent with energy transfer in FbC‐pe‐FbB occurring predominantly by a through‐space mechanism. The energy‐transfer characteristics of FbC‐pe‐FbB are compared with those previously obtained for analogous phenylethyne‐linked dyads consisting of two porphyrins or two oxochlorins. The comparisons among the sets of dyads are facilitated by density functional theory calculations that elucidate the molecular‐orbital characteristics of the energy donor and acceptor constituents. The electron‐density distributions in the frontier molecular orbitals provide insights into the through‐bond electronic interactions that can also contribute to the energy‐transfer process in the different types of dyads.
The Phototoxicity of Aged Human Retinal Melanosomes†
Authors: Różanowski Bartosz , Cuenco Joyceline , Davies Sallyanne , Shamsi Farukh A. , Żądło Andrzej , Dayhaw‐Barker Pierrette , Róz˙anowska Małgorzata , Sarna Tadeusz , Boulton Michael E.
Published: April 2008

The purpose of this study was to determine whether an age‐related increase in photoreactivity of human retinal melanosomes (MS) can cause phototoxicity to retinal pigment epithelium (RPE) cells. MS were isolated post mortem from young (20–30 years, young human melanosomes [YHMs]) and old (60–90 years, old human melanosomes [OHMs]) human eyes and from young bovine eyes (bovine melanosomes [BMs]). Confluent cultured ARPE‐19 cells were fed equivalent numbers of OHMs or BMs and accumulated similar amounts of melanin as determined by electron paramagnetic resonance assay. Cells with and without MS were either maintained in the dark or exposed to blue light for up to 96 h and assessed for alterations in cell morphology, cell viability and lysosomal integrity. Incubation of cells in dark in the presence of internalized MS or irradiation of cells with blue light in the absence or presence of BMs did not significantly affect cell viability. However, exposures to blue light in the presence of OHMs resulted in abnormal cell morphology, up to ∼75% decrease in mitochondrial activity, loss of lysosomal pH and cell death. OHMs contained significantly less melanin than YHMs, supporting the hypothesis that melanin undergoes degradation during RPE aging. Our results demonstrate that aged MS can be phototoxic to human RPE cells and support a contributing role of MS in RPE aging and in the pathogenesis of age‐related macular degeneration.
Promotion of PDT Efficacy by a Bcl‐2 Antagonist
Authors: Kessel David
Published: April 2008

Photodynamic therapy (PDT) directed against the endoplasmic reticulum (ER) is also known to target antiapoptotic Bcl‐2 family proteins. This effect is associated with the initiation of both apoptosis, a cell death pathway, and autophagy, an organelle recycling system that can lead to survival or cell death. In this study, we examined the ability of the Bcl‐2 antagonist HA14‐1 to promote the photodynamic efficacy of PDT directed at the ER. At concentrations that independently caused only a small loss of viability, HA14‐1 markedly enhanced the proapoptotic and phototoxic effects of ER photodamage. These results provide additional evidence that the antiapoptotic properties of Bcl‐2 constitute an important determinant of photokilling, and demonstrate that synergistic effects can result when PDT is coupled with pharmacologic suppression of Bcl‐2 function.
Effect of Dimerization on Vibrational Spectra of Eumelanin Precursors†
Authors: Nighswander‐Rempel Stephen P. , Olsen Seth , Mahadevan Indumathy B. , Netchev George , Wilson Brian C. , Smith Sean C. , Rubinsztein‐Dunlop Halina , Meredith Paul
Published: April 2008

We have synthesized a compound ideally suited to the study of structure‐function relationships in eumelanin synthesis. N‐methyl‐5‐hydroxy‐6‐methoxy‐indole (MHMI) has key functional groups strategically placed on the indole framework to hinder binding in the 2, 5, 6 and 7 positions. Thus, the dimer bound exclusively in the 4‐4′ positions was isolated and characterized. In order to study the difference in vibrational structure between the MHMI monomer and dimer, Raman spectra were acquired of both compounds, as well as indole, indole‐2‐carboxylic acid and 5,6‐dihydroxyindole‐2‐carboxylic acid (DHICA). Peaks were assigned to particular vibrational modes using B3LYP density functional theory calculations, and experimental and theoretical spectra displayed good agreement. Addition of functional groups to either benzene or pyrrole rings in the indole framework impacted vibrational spectra attributed to vibrations in either ring, and in some cases, peaks appearing unchanged between two compounds corresponded to different contributing vibrations. Dimerization resulted in an expected increase in the number of vibrational modes, but not a significant increase in the number of apparent peaks, as several modes frequently contributed to an individual observed peak. Comparison of spectral features of the monomer and dimer provides insight into eumelanin photochemistry, but final conclusions depend on the planarity of oligomeric structure in vivo.
Multicolor Fluorescence Imaging of Leaves—A Useful Tool for Visualizing Systemic Viral Infections in Plants†
Authors: Pineda Mónica , Gáspár László , Morales Fermín , Szigeti Zoltán , Barón Matilde
Published: April 2008

Multicolor fluorescence induced by UV light is a sensitive and specific tool that may be used to provide information about the primary and secondary metabolism of plants by monitoring signals of the chlorophyll fluorescence (Chl‐F) and blue‐green fluorescence (BGF), respectively. We have followed the systemic infection of Nicotiana benthamiana plants with the Pepper mild mottle virus (PMMoV) by means of a multicolor fluorescence‐imaging system, to detect differences between two strains of PMMoV during the infection process and to establish a correlation between the virulence and changes induced in the host plant. Changes in both BGF and Chl‐F were monitored. BGF increased mainly in the abaxial side of the leaf during pathogenesis and the corresponding images showed a clear vein‐associated pattern in leaves of infected plants. HPLC analysis of leaf extracts was carried out to identify compounds emitting BGF, and determined that chlorogenic acid was one of the main contributors. BGF imaging was able to detect viral‐induced changes in asymptomatic (AS) leaves before detection of the virus itself. Chl‐F images confirmed our previous results of alterations in the photosynthetic apparatus of AS leaves from infected plants that were detected with other imaging techniques. Fluorescence ratios F440/F690 and F440/F740, which increase during pathogenesis, were excellent indicators of biotic stress.
Exposure to Increased Ambient Ultraviolet B Radiation has Negative Effects on Growth, Condition and Immune Function of Juvenile Atlantic Salmon (Salmo salar)
Authors: Jokinen Ilmari E. , Markkula Eveliina S. , Salo Harri M. , Kuhn Penny , Nikoskelainen Sami , Arts Michael T. , Browman Howard I.
Published: April 2008

Atlantic salmon (Salmo salar) parr were exposed in two outdoor experiments, ranging in duration from 52 to 137 days, to spectral treatments: (1) natural sunlight (=present ambient UVB level), (2) solar radiation supplemented with enhanced UVB radiation from lamps simulating 20% or 8% stratospheric ozone loss or (3) UVB‐depleted sunlight achieved by screening with Mylar‐D film. The growth, condition and immune function of the salmon were quantified after treatments. Exposure to enhanced UVB radiation retarded growth, and decreased hematocrit value and plasma protein concentration. Further, enhanced UVB radiation affected plasma immunoglobulin concentration. The results demonstrate that juvenile Atlantic salmon are not able to fully adapt to increased ambient UVB levels in long‐term exposures, and the interference with immune system function suggests a negative effect of UVB on disease resistance in Atlantic salmon.
For Better and Worse: Social Influences on Coronary Heart Disease Risk
Authors: Ruiz John M. , Hutchinson James G. , Terrill Alexandra L.
Published: April 2008

From the neighborhoods we live in to those we marry, other people are a part of our everyday lives. Mounting evidence suggests that these social factors constitute risk and resilience influences for coronary heart disease (CHD). The current aim is to summarize the literature into four representative categories relating to CHD risk: social environments, social roles, social resources, and close relationships. The argument is made that these factors moderate and mediate stress and associated physiological responses constituting a psychosomatic pathway to disease.
Visual fields in children with attention‐deficit / hyperactivity disorder before and after treatment with stimulants
Authors: Martin Lene , Aring Eva , Landgren Magnus , Hellström Ann , Andersson Grönlund Marita
Published: April 2008

Purpose:  This study aimed to evaluate visual function in children with attention‐deficit/hyperactivity disorder (ADHD), to correlate these data with the morphology of the optic nerve, and to find out if and how psychostimulant medication affects visual functions.

Methods:  The visual acuity (VA) and visual fields (VFs) of 18 children with ADHD (two girls and 16 boys), aged 6–17 years, were examined before and after treatment with psychostimulants. A control group, consisting of 24 children (nine girls and 15 boys), aged 7–18 years, were examined twice to evaluate the repeatability of the tests and the learning effect. Fundus photographs were analysed by digital planimetry.

Results:  Visual acuity increased significantly (p = 0.0039) in the ADHD group after treatment. The difference between the two VF examinations was significantly larger in the ADHD group compared with the control group (p = 0.036). Significantly more ADHD subjects had subnormal VF results without stimulants, compared with controls (p = 0.0043), but with stimulants the difference was no longer significant.

Conclusions:  Children with ADHD showed better VA and VF results with than without psychostimulant medication.
Patterns of hepatocellular carcinoma incidence in Egypt from a population‐based cancer registry
Authors: Lehman Elizabeth M. , Soliman Amr S. , Ismail Kadry , Hablas Ahmed , Seifeldin Ibrahim A. , Ramadan Mohamed , El‐Hamzawy Hesham , Shoushtari Christiana S. , Wilson Mark L.
Published: April 2008

Aim:  Hepatocellular carcinoma (HCC) is increasing worldwide, and is frequently attributed to rising rates of hepatitis C virus infection and interactions between viral and environmental risk factors. Because of Egypt's unique risk factor profile, we analyzed data from the Gharbiah Population‐Based Cancer Registry for the period 1999–2003 to characterize demographic and geographic patterns of cases in this province.

Methods:  We calculated age‐ and sex‐specific and age‐ and sex‐standardized HCC incidence rates for the eight districts in Gharbiah. We also compared rates from Gharbiah with the USA (US Surveillance Epidemiology and End Results [SEER] database).

Results:  The analysis revealed a higher incidence in males than in females, significant geographic variations among districts, and a higher incidence in Gharbiah than that reported by SEER.

Conclusion:  The findings of this study document the heterogeneous distribution of HCC at regional and international levels. This population‐based registry offers the opportunity for careful representative studies of various etiologies, particularly infectious and/or environmental factors that may contribute to risk.
Sclerosed hemangioma of the liver: Report of a case and review of the literature
Authors: Mori Hiroki , Ikegami Toru , Imura Satoru , Shimada Mitsuo , Morine Yuji , Kanemura Hirofumi , Arakawa Yusuke , Kanamoto Mami , Hanaoka Jun , Sugimoto Koji , Tokunaga Takuya
Published: April 2008

A sclerosed hemangioma of the liver is an extremely rare type of benign hepatic tumor. A 77‐year‐old female was referred to Tokushima University Hospital with fever, abnormal liver function tests and a large liver mass. The tumor, 10 × 5 cm in size and located in segment 5–6 of the liver, was depicted as a low density tumor with enhancement by computed tomography (CT). Magnetic resonance imaging (MRI) showed it to be a tumor with a low signal on T1‐weighted and a high signal on T2‐weighted images. The patient was negative for hepatitis B surface antigen and hepatitis C antibody. She underwent a right hepatectomy for possible malignant liver tumors, including intrahepatic cholangiocarcinoma or fibrolamellar hepatocellular carcinoma. The following histological examination of the surgical specimen revealed the tumor to be a hepatic sclerosed hemangioma with characteristic dense collagenous tissues. We report here on the case of this unusual tumor and review the relevant literature.
Some Explicit Results for the Mean Spherical Approximation for Mixtures of Yukawa Fluids
Authors: Henderson Douglas J. , Scalise Osvaldo H.
Published: April 2008

The mean spherical approximation (MSA) is of interest because it produces an integral equation that yields useful analytical results for a number of fluids. One such case is the Yukawa fluid, which is a reasonable model for a simple fluid. The original MSA solution for this fluid, due to Waisman, is analytic but not explicit. Ginoza has simplified this solution. However, Ginoza's result is not quite explicit. Some years ago, Henderson, Blum, and Noworyta obtained explicit results for the thermodynamic functions of a single-component Yukawa fluid that have proven useful. They expanded Ginoza's result in an inverse-temperature expansion. Even when this expansion is truncated at fifth, or even lower, order, this expansion is nearly as accurate as the full solution and provides insight into the form of the higher-order coefficients in this expansion. In this paper Ginoza's implicit result for the case of a rather special mixture of Yukawa fluids is considered. Explicit results are obtained, again using an inverse-temperature expansion. Numerical results are given for the coefficients in this expansion. Some thoughts concerning the generalization of these results to a general mixture of Yukawa fluids are presented.
Onshore migration of a deep-water brachiopod fauna from the Lower Ordovician Tonggao Formation, Jiangnan Slope, southeastern Guizhou Province, South ChinaThis article is one of a series of papers published in this Special Issue on the theme The dynamic reef and shelly communities of the Paleozoic. This Special is in honour of our colleague and friend Paul Copper.
Authors: Zhan Renbin , Jin Jisuo
Published: April 2008

Brachiopods from the lower Tonggao Formation (Floian, late Early Ordovician) of Sandu, southeastern Guizhou Province, represent a deep-water benthic shelly fauna from the Jiangnan Slope facies of the South China paleoplate. The fauna contains 16 brachiopod taxa, with orthides, lingulates, and pentamerides being the common groups. Concurrent graptolites confine the brachiopod fauna to the Tetragraptus approximatus and the Acrograptus filiformis biozones (early Floian). The first appearance datum (FAD) of several brachiopod genera, such as Paralenorthis , Protoskenidioides , and Nereidella , in the Sandu slope facies is one or two graptolitic biozones lower than their FAD in shallower water facies on the Yangtze Platform. Later in the late Floian, these genera became major components of the Sinorthis fauna that flourished over much of the Yangtze Platform, suggesting a migration of the benthic shelly fauna from slope to platform facies during the Floian radiation in South China. Compared to the platform fauna, the deep-water brachiopod fauna of the Sandu area has a lower level of richness, diversity, and community organization. Three brachiopod associations are recognized: the Paralenorthis–Nereidella, the Palaeoglossa longa , and the Lingulella –Protoskenidioides associations. An upsection decrease in shell size, faunal richness, and species diversity in the Tonggao Formation indicate a deteriorating environment towards hypersalinity in the Sandu area, resulting in the ultimate disappearance of the deep-water brachiopod fauna.
The Holdfast of Gilbertsocrinus tuberosus (Mississippian, Crinoidea)This article is one of a selection of papers published in this Special Issue on the theme The dynamic reef and shelly communities of the Paleozoic. This Special is in honour of our colleague and friend Paul Copper.
Authors: Hollis Kathy A. , Ausich William I.
Published: April 2008

Gilbertsocrinus is a common Middle Devonian to Lower Mississippian crinoid from Europe, North America, and China. This crinoid has several very unusual features, such as tegmen appendages, minute arms, a very flexible column, and an unusual holdfast. It is demonstrated that a bulbous holdfast does not exist in Gilbertsocrinus, as previously interpreted. Gilbertsocrinus is an unusual crinoid; however, it has a distal coil rather than a tuberous holdfast.
Ginger attenuates acetylcholine-induced contraction and Ca2+ signalling in murine airway smooth muscle cells
Authors: Ghayur Muhammad N. , Gilani Anwar H. , Janssen Luke J.
Published: April 2008

Asthma is a chronic disease characterized by inflammation and hypersensitivity of airway smooth muscle cells (ASMCs) to different spasmogens. The past decade has seen increased use of herbal treatments for many chronic illnesses. Ginger ( Zingiber officinale ) is a common food plant that has been used for centuries in treating respiratory illnesses. In this study, we report the effect of its 70% aqueous methanolic crude extract (Zo·Cr) on acetylcholine (ACh)-induced airway contraction and Ca2+ signalling in ASMCs using mouse lung slices. Airway contraction and Ca2+ signalling, recorded via confocal microscopy, were induced with ACh, either alone or after pretreatment of slices with Zo·Cr and (or) verapamil, a standard Ca2+ channel blocker. ACh (10 μmol/L) stimulated airway contraction, seen as decreased airway diameter, and also stimulated Ca2+ transients (sharp rise in [Ca2+]i) and oscillations in ASMCs, seen as increased fluo-4-induced fluorescence intensity. When Zo·Cr (0.3–1.0 mg/mL) was given 30 min before ACh administration, the ACh-induced airway contraction and Ca2+ signalling were significantly reduced. Similarly, verapamil (1 μmol/L) also inhibited agonist-induced airway contraction and Ca2+ signalling, indicating a similarity in the modes of action. When Zo·Cr (0.3 mg/mL) and verapamil (1 μmol/L) were given together before ACh, the degree of inhibition was the same as that observed when each of these blockers was given alone, indicating absence of any additional inhibitory mechanism in the extract. In Ca2+-free solution, both Zo·Cr and verapamil, when given separately, inhibited Ca2+ (10 mmol/L)-induced increase in fluorescence and airway contraction. This shows that ginger inhibits airway contraction and associated Ca2+ signalling, possibly via blockade of plasma membrane Ca2+ channels, thus reiterating the effectiveness of this age-old herb in treating respiratory illnesses.
Arsenic distribution in mesquite (

Prosopis laevigata

) and huizache (

Acacia farnesiana

) in the Zimapán mining area, México
Authors: Armienta M.A. , Ongley L.K. , Rodríguez R. , Cruz O. , Mango H. , Villaseñor G.
Published: April 2008

Arsenic concentrations have been determined in mesquite (
Prosopis laevigata
) and huizache (
Acacia farnesiana
) growing on As-rich soils in the semi-arid mining area of Zimapán, México. The elevated As contents in the substrates (up to 32 000 mg/kg) were reflected in the dry weight concentrations of twigs (up to 82.7 mg/kg in mesquite and 225 mg/kg in huizache), and leaves (up to 78.2 mg/kg in mesquite and 67.0 mg/kg in huizache). Arsenic concentrations in twigs and leaves collected in less impacted soils (containing up to 110 mg/kg of As) reached a maximum of 20.8 mg/kg in mesquite twigs and 27.8 mg/kg in mesquite leaves. Differences of several orders of magnitude in surface substrate As concentrations were not reflected in plant As contents. A low proportion of available As in substrates, as well as deep plant roots which may reach less contaminated sediments, explains this behaviour. The pod As concentrations from tailings-affected sites were not significantly different from background samples. Nearly all mesquites and huizaches from the high-As substrates were above standards for foodstuffs. The As concentration in vegetation growing on soils affected by tailings and smelter/slags points to a potential contamination of the food chain, mainly through goats, the most common mammals in the area. Mesquites and huizaches are not hyperaccumulators but are As-tolerant plants and can therefore be considered as an option for a remediation programme to stabilize eroding tailings.
Thompson–Howarth error analysis: unbiased alternatives to the large-sample method for assessing non-normally distributed measurement error in geochemical samples
Authors: Stanley Clifford R. , Lawie David
Published: April 2008

The Thompson–Howarth error analysis procedures have become common in geochemical applications for assessing the magnitude of measurement error at any stage of determination (initial sampling, sample preparation, geochemical analysis). However, the large-sample method, as defined by Thompson and Howarth, which relies on an assumption that the measurement errors are normally distributed, produces significantly biased results when the errors are not normally distributed. Four examples of quality control data-sets from a variety of mineral deposit types illustrate that normally distributed errors are probably the exception rather than the rule in ore deposits, and non-normally distributed geochemical data-sets may exist in other geological materials. As a result, using Thompson and Howarth's large-sample error analysis approach, geoscientists may obtain a significantly inaccurate estimate of the quality of their geochemical concentration data.

Two new methods, which are modifications to the Thompson–Howarth large-sample technique, eliminate this bias because they ensure that the results are independent of a normally distributed error assumption. Regression of group root mean square standard deviations produces accurate error estimates, at least provided that the concentrations are distributed relatively evenly across their range. Similarly, regression of duplicate variances against duplicate means using a quadratic model, and then taking the square root of this model, also results in an unbiased estimate of measurement error. Furthermore, if this quadratic model is a perfect square, then the square root of the quadratic model will be linear on a mean
versus
standard deviation scatterplot. This approach is further independent of the distribution of the error in the data. Using these modified approaches, geoscientists can now obtain unbiased Thompson–Howarth estimates of measurement error that is not normally distributed in quality control/quality assessment programmes.
Niobium in boreal stream waters and brackish-water sediments
Authors: Åström Mats E. , Peltola Pasi , Virtasalo Joonas J. , Kotilainen Aarno T. , Salminen Reijo
Published: April 2008

The focus is on ‘non-detrital’ Nb in boreal stream waters (dissolved fraction and acid-available particulate fraction) and brackish-water/lacustrine sediments (aqua regia extractable fraction). Spatial patterns, temporal trends and speciation experiments all point to dissolved humic substances and colloidal Fe as the main control of Nb concentrations in stream waters. In addition, clay-silt deposits and/or ore deposits may be responsible for producing local streamwater Nb anomalies. In groundwater in overburden (glacial till) overlying Proterozoic granitoids, dissolved Nb concentrations were about an order of magnitude higher than in stream waters and strongly correlated with dissolved Fe. In the brackish-water sediments, the Nb concentrations (1.33–4.20 ppm) were higher than in the lacustrine ones (0.25–0.53 ppm). To explain this, we assessed the potential role of organic material, biological processes, sulphide mineralogy, silicate mineralogy and input factors. However, none of them could satisfactorily explain the observed Nb geochemical features. Although Nb can be considered relatively immobile, the data presented in this paper show that under certain conditions its abundance in the aquatic environment increases.
Quantitative assessment of the success of geochemical exploration techniques using minimum probability methods
Authors: Stanley Clifford R. , Noble Ryan R.P.
Published: April 2008

Hypergeometric statistics have been used to establish a quantitative measure of performance for geochemical exploration techniques over known mineral showings. An alternative and complementary measure of exploration performance is geochemical contrast, which determines how convincing or compelling a geochemical result is. Using the identical philosophy employed to assess exploration ‘accuracy’, the Student's
t
distribution is used to create a quantitative measure of ‘geochemical contrast’. First, thresholds are selected to separate anomalous and background populations. Then, Student's
t
test statistics for each of these sets of anomalous and background samples are calculated, and the Student's
t
probability is determined for the highest test statistic. This probability describes the chance that the anomalous and background populations were derived from the same underlying distribution. If this probability is low, then the concentrations of the anomalous and background samples are very different, and high geochemical contrast exists. If this probability is high, the alternative is true. As a result, this approach can be used to quantitatively compare the geochemical contrast of competing exploration techniques. Furthermore, because both of these ‘accuracy’ and ‘geochemical contrast’ measures are probabilities that vary inversely with exploration performance, their joint probability (their product) can be used to collectively rate the performance of exploration techniques.
Variation in geochemical background levels for Jamaican soils
Authors: Garrett Robert G. , Lalor Gerald C. , Preston John , Vutchkov M.K.
Published: April 2008

The complex soils of Jamaica may be subdivided into three groups on the basis of their Fe/Na concentration ratio, which reflects their genetic and pedological development, and the geochemical diversity of their parent materials. The three groups are non-Terra Rossa soils with Fe/Na concentration ratios of <40, Terra Rossa soils with Fe/Na 40–320, and bauxitic soils with Fe/Na >320. A series of ANOVAs demonstrate that the geometric means of As, Cu, Pb, Zn, Cd, Hg, Cr, U and Sm are significantly different from each other for all subpopulations, with the exception of Zn and Hg in Terra Rossa and bauxitic soils. A combination of the Tukey boxplot procedure and the visual inspection of cumulative probability plots is used to estimate the ranges of natural background for the above elements in the three soil environments. It is noted that these estimates based on total and near-total analyses overestimate the actual amounts of the elements that are bioaccesible.
Age-related changes in renal and hepatic cellular mechanisms associated with variations in rat serum thyroid hormone levels
Authors: Silvestri Elena , Lombardi Assunta , de Lange Pieter , Schiavo Luigi , Lanni Antonia , Goglia Fernando , Visser Theo J. , Moreno Maria
Published: April 2008

Aging is associated with changes in thyroid gland physiology. Age-related changes in the contribution of peripheral tissues to thyroid hormone serum levels have yet to be systematically assessed. Here, we investigated age-related alterations in the contributions of the liver and kidney to thyroid hormone homeostasis using 6-, 12-, and 24-mo-old male Wistar rats. A significant and progressive decline in plasma thyroxine occurred with age, but triiodothyronine (T3) was decreased only at 24 mo. This was associated with an unchanged protein level of the thyroid hormone transporter monocarboxylate transporter 8 (MCT8) in the kidney and with a decreased MCT8 level in the liver at 24 mo. Hepatic type I deiodinase (D1) protein level and activity declined progressively with age. Renal D1 levels were decreased at both 12 and 24 mo but D1 activity was decreased only at 24 mo. In the liver, no changes occurred in thyroid hormone receptor (TR) TRα1, whereas a progressive increase in TRβ1 occurred at both mRNA and total protein levels. In the kidney, both TRα1 and TRβ1 mRNA and total protein levels were unchanged between 6 and 12 mo but increased at 24 mo. Interestingly, nuclear TRβ1 levels were decreased in both liver and kidney at 12 and 24 mo, whereas nuclear TRα1 levels were unchanged. Collectively, our data show differential age-related changes among hepatic and renal MCT8 and D1 and TR expressions, and they suggest that renal D1 activity is maintained with age to compensate for the decrease in hepatic T3 production.
An in vivo and in vitro assessment of TOR signaling cascade in rainbow trout (Oncorhynchus mykiss)
Authors: Seiliez Iban , Gabillard Jean-Charles , Skiba-Cassy Sandrine , Garcia-Serrana Daniel , Gutiérrez Joaquim , Kaushik Sadasivam , Panserat Stephane , Tesseraud Sophie
Published: April 2008

In mammals, feeding promotes protein accretion in skeletal muscle through a stimulation of the insulin- and amino acid- sensitive mammalian target of rapamycin (mTOR) signaling pathway, leading to the induction of mRNA translation. The purpose of the present study was to characterize both in vivo and in vitro the activation of several major kinases involved in the mTOR pathway in the muscle of the carnivorous rainbow trout. Our results showed that meal feeding enhanced the phosphorylation of the target of rapamycin (TOR), PKB, p70 S6 kinase, and eIF4E-binding protein-1, suggesting that the mechanisms involved in the regulation of mRNA translation are well conserved between lower and higher vertebrates. Our in vitro studies on primary culture of trout muscle cells indicate that insulin and amino acids regulate TOR signaling and thus may be involved in meal feeding effect in this species as in mammals. In conclusion, we report here for the first time in a fish species, the existence and the nutritional regulation of several major kinases involved in the TOR pathway, opening a new area of research on the molecular bases of amino acid utilization in teleosts.
Adverse Reactions to Food: Allergies and Intolerances
Authors: Montalto Massimo , Santoro Luca , D’Onofrio Ferruccio , Curigliano Valentina , Gallo Antonella , Visca Dina , Cammarota Giovanni , Gasbarrini Antonio , Gasbarrini Giovanni
Published: April 2008

All the anomalous reactions secondary to food ingestion are defined as ‘adverse reactions to food’. In 1995 the European Academy of Allergology and Clinical Immunology suggested a classification on the basis of the responsible pathogenetic mechanism; according to this classification, non-toxic reactions can be divided into ‘food allergies’ when they recognize immunological mechanisms, and ‘food intolerances’ when there are no immunological implications. The diagnostic approach to adverse reactions to food is based on accurate clinical history and objective examination, and further execution of specific tests when allergy or intolerance is suspected. The therapy for food allergies is the elimination of the food to which hypersensibility has been found; this strategy can lead, especially in pediatric age, to tolerance. If elimination diets cannot be completely performed, or if it is not possible to identify the food to eliminate, some drugs (e.g. antihistaminics, steroids, etc.) can be administered. Specific allergen immunotherapy has been recently introduced. Fundamental is food allergy prevention, especially in high-risk subjects. The therapeutic approach to secondary food intolerances is based principally on primitive disease resolution; on the other hand, some specific treatments (e.g. β-galactosidases in lactose malabsorption) are available in case of primary intolerance.
Classification of Malabsorption Syndromes
Authors: Montalto Massimo , Santoro Luca , D’Onofrio Ferruccio , Curigliano Valentina , Visca Dina , Gallo Antonella , Cammarota Giovanni , Gasbarrini Antonio , Gasbarrini Giovanni
Published: April 2008

Malabsorption syndrome is usually defined as the complex of symptoms secondary to maldigestion and/or malabsorption, realizing when the extension of the disease exceeds the ability of intestine compensation. Several conditions have been recognized as being responsible for this syndrome. Up to now, different criteria have been used to order them, but a definitive classification is still not available because of the complexity of the absorption process, the involvement of different organs and structures, and the coexistence of different mechanisms in some diseases causing malabsorption. We propose a new classification of diseases causing malabsorption syndrome according to the responsible etiopathogenetic mechanisms: (a) alteration of digestive processes; (b) alteration of uptake and transport caused by damage or reduction of absorption surface, and (c) miscellaneous. A comment about the mechanisms responsible for malabsorption is given for all the cited diseases.
Role of the Brain-Gut Axis in the Pathophysiology of Crohn’s Disease
Authors: Stasi Cristina , Orlandelli Ermes
Published: April 2008

Studies on the interaction between the central nervous system and the gastrointestinal system have shed light on the neurobiological response to stress via the hypothalamic-pituitary-adrenal and the hypothalamic-autonomic nervous system axes. These findings support a role of psychological and environmental factors in the course of gastrointestinal disorders and their influence on the neuroendocrine regulation of the immune system. Crohn’s disease (CD) is a chronic inflammatory condition of the gastrointestinal tract, whose etiology involves genetic, psychological, immune and inflammatory factors. A higher prevalence of psychiatric diagnosis has been observed in CD patients. Both longitudinal and cross-sectional studies have explored the relationship between psychological stress and severity and/or clinical course of CD, with different, even conflicting, results. In several chronic diseases and stress-related psychological disorders, an alteration has been observed of the HPA response that through glucocorticoids modulate the immune/inflammatory reaction. In animal models of colitis, psychological or environmental stress may increase gastrointestinal permeability, allowing abnormal antigen presentation to the immune system and leading to the exacerbation and perpetuation of intestinal inflammation. The increased intestinal permeability under stress is mediated by corticotropin-releasing hormone stimulation through nicotinic, adrenergic and cholinergic receptors, suggesting a complex interplay between sympathetic and parasympathetic nervous systems. This review will examine and discuss the relationship between psychological stress and CD, investigating the role played by the hypothalamic-pituitary-adrenal and the hypothalamic-autonomic nervous system axes in stress-related psychological disorders, and the possible influence of chronic stress on the intestinal inflammation, in particular in CD.