bluuebunny/crossref_metadata_2025 huggingface dataset:
Respiration of midges (Diptera; Chironomidae) in British Columbian lakes: oxy‐regulation, temperature and their role as palaeo‐indicators
Authors: BRODERSEN KLAUS PETER , PEDERSEN OLE , WALKER IAN R. , JENSEN MICHAEL TRANEKJÆR
Published: January 2008

1. The specific respiration rate of 13 chironomid taxa and Chaoborus were measured to test the hypothesis of the relation between a species’ ability to regulate their oxygen uptake and their distributional patterns among nine study lakes in British Columbia, Canada.

2. Respiration patterns of individual taxa were modelled using piecewise linear regression with break point and simple hyperbolic functions. Three types of respiration curves were identified: (i) classical oxy‐conformers (e.g. littoral Cricotopus) which cannot sustain a sufficient oxygen uptake with decreasing oxygen availability; (ii) oxy‐regulators (e.g. profundal Chironomus) which can regulate and maintain a constant respiration until a certain critical point and (iii) oxy‐stressors (Micropsectra) which increase their respiration rate with decreasing oxygen availability until a critical point.

3. Respiration was measured at two different temperatures (10 and 20 °C), and over the range of oxygen saturation conditions studied here (0–90%) mean Q10 values varied from 1.3 to 2.5.

4. The results show that different chironomid taxa have varying sensitivity to low oxygen concentrations and different respiratory responses to increased temperature. The critical point increased to higher oxygen saturation for six taxa, decreased for one taxon and was unchanged for two taxa.

5. The results illustrate one of the possible biological mechanisms behind the use of chironomids as temperature and climate indicators in palaeoecological studies by exploring the link between temperature and respiration physiology.
Growth of an invertebrate shredder on native (Populus) and non‐native (Tamarix, Elaeagnus) leaf litter
Authors: MOLINE ANGELA B. , POFF N. L.
Published: January 2008

1. Large‐scale invasions of riparian trees can alter the quantity and quality of allochthonous inputs of leaf litter to streams and thus have the potential to alter stream organic matter dynamics. Non‐native saltcedar (Tamarix sp.) and Russian olive (Elaeagnus angustifolia) are now among the most common trees in riparian zones in western North America, yet their impacts on energy flow in streams are virtually unknown.

2. We conducted a laboratory feeding experiment to compare the growth of the aquatic crane fly Tipula (Diptera: Tipulidae) on leaf litter from native cottonwood (Populus) and non‐native Tamarix and Elaeagnus. Tipula showed positive growth on leaf litter of all three species; however, after 7 weeks, larvae fed Tamarix leaves averaged 1.7 and 2.5 times the mass of those fed Elaeagnus and Populus, respectively. Tipula survival was highest on Populus, intermediate on Tamarix and lowest on Elaeagnus.

3. High Tipula growth on Tamarix probably reflects a combination of leaf chemistry and morphology. Conditioned Tamarix leaf litter had intermediate carbon : nitrogen values (33 : 1) compared to Populus (40 : 1) and Elaeagnus (26 : 1), and it had intermediate proportions of structural carbon (42%) compared to Elaeagnus (57%) and Populus (35%). Tamarix leaves are also relatively small and possibly more easily ingested by Tipula than either Elaeagnus or Populus.

4. Field surveys of streams in the western U.S.A. revealed that Tamarix and Elaeagnus leaf packs were rare compared to native Populus, probably due to the elongate shape and small size of the non‐native leaves. Thus we conclude that, in general, the impact of non‐native riparian invasion on aquatic shredders will depend not only on leaf decomposition rate and palatability but also on rates of leaf litter input to the stream coupled with streambed retention and subsequent availability to consumers.
Peptidoglycan and lipopolysaccharide activate PLCγ2, leading to enhanced cytokine production in macrophages and dendritic cells
Authors: Aki Daisuke , Minoda Yasumasa , Yoshida Hideyuki , Watanabe Satoko , Yoshida Ryoko , Takaesu Giichi , Chinen Takatoshi , Inaba Toshiya , Hikida Masaki , Kurosaki Tomohiro , Saeki Kazuko , Yoshimura Akihiko
Published: January 2008

In macrophages and monocytes, microbial components trigger the production of pro‐inflammatory cytokine through Toll‐like receptors (TLRs). Although major TLR signaling pathways are mediated by serine/threonine kinases, including TAK1, IKK and MAP kinases, tyrosine phosphorylation of intracellular proteins by TLR ligands has been suggested in a number of reports. Here, we demonstrated that peptidoglycan (PGN) of a Gram‐positive bacterial cell wall component, a TLR2 ligand and lipopoysaccharide (LPS) of a Gram‐positive bacterial component, a TLR4 ligand induced tyrosine phosphorylation of phospholipase Cγ‐2 (PLCγ2), leading to intracellular free Ca2+ mobilization in bone marrow‐derived macrophages (BMMφ) and bone marrow‐derived dendritic cells (BMDC). PGN‐ and LPS‐induced Ca2+ mobilization was not observed in BMDC from PLCγ2 knockout mice. Thus, PLCγ2 is essential for TLR2 and TLR4‐mediated Ca2+ flux. In PLCγ2‐knockdown cells, PGN‐induced IκB‐α phosphorylation and p38 activation were reduced. Moreover, PLCγ2 was necessary for the full production of TNF‐α and IL‐6. These data indicate that the PLCγ2 pathway plays an important role in bacterial ligands‐induced activation of macrophages and dendritic cells.
The new geological map of East Greenland
Authors: Brooks Kent
Published: January 2008

NE Greenland has seen epic polar exploration, bitter territorial disputes, scientific skulduggery but contains some of the world's most striking scenery and geology. It is now documented with a new geological map from 70°N to 82°N, which documents the architecture of the Caledonian mountain range over 1300km.
Response of soil surface CO2 flux in a boreal forest to ecosystem warming
Authors: BRONSON DUSTIN R. , GOWER STITH T. , TANNER MYRON , LINDER SUNE , VAN HERK INGRID
Published: January 2008

Soil surface carbon dioxide (CO2) flux (RS) was measured for 2 years at the Boreal Soil and Air Warming Experiment site near Thompson, MB, Canada. The experimental design was a complete random block design that consisted of four replicate blocks, with each block containing a 15 m × 15 m control and heated plot. Black spruce [Picea mariana (Mill.) BSP] was the overstory species and Epilobium angustifolium was the dominant understory. Soil temperature was maintained (∼5 °C) above the control soil temperature using electric cables inside water filled polyethylene tubing for each heated plot. Air inside a 7.3‐m‐diameter chamber, centered in the soil warming plot, contained approximately nine black spruce trees was heated ∼5 °C above control ambient air temperature allowing for the testing of soil‐only warming and soil+air warming. Soil surface CO2 flux (RS) was positively correlated (P < 0.0001) to soil temperature at 10 cm depth. Soil surface CO2 flux (RS) was 24% greater in the soil‐only warming than the control in 2004, but was only 11% greater in 2005, while RS in the soil+air warming treatments was 31% less than the control in 2004 and 23% less in 2005. Live fine root mass (< 2 mm diameter) was less in the heated than control treatments in 2004 and statistically less (P < 0.01) in 2005. Similar root mass between the two heated treatments suggests that different heating methods (soil‐only vs. soil+air warming) can affect the rate of decomposition.
Outcome of an oral health outreach programme for preschool children in a low socioeconomic multicultural area
Authors: WENNHALL INGER , MATSSON LARS , SCHRÖDER ULLA , TWETMAN SVANTE
Published: January 2008

Background.  Despite a significant reduction in the prevalence of dental caries, childhood tooth decay is still a public health problem in both developed and developing countries.

Objective.  The aim of this study was to evaluate the caries preventive effect of an oral health programme for preschool children living in a low socioeconomic multicultural area in the city of Malmö, Sweden.

Methods.  Eight hundred and four 2‐year‐old children were enrolled and recalled every third month between ages 2 and 3 and semi‐annually between ages 3 and 5 years. From an outreach facility, parents were instructed on oral health with a focus on toothbrushing and diet, and provided fluoride tablets free of charge. Participants completed a clinical examination and a structured interview at age of 5 years, at which point 651 children (81%) remained in the programme. The results of the intervention group were compared with a non‐intervention reference group consisting of 201 5‐year‐old children from the same district.

Results.  In the intervention group, 96% attended four or more of their scheduled appointments, and mean caries prevalence was significantly lower than in the reference group (5.4 deft vs. 6.9 deft; P < 0.001). The prevented defs fraction was 27%. Parents’ daily assistance with toothbrushing and administering fluoride tablets was significantly better in the intervention group than in the reference group (P < 0.05).

Conclusion.  This study demonstrated that the early start of oral health programme had a significant beneficial effect on caries prevalence after 3 years.
Evaluation of the immune response against Strongyloides venezuelensis in antigen‐immunized or previously infected mice
Authors: FERNANDES A. , PEREIRA A. T. M. , ESCHENAZI P. D. , SCHILTER H. C. , SOUSA A. L. S. , TEIXEIRA M. M. , NEGRÃO‐CORRÊA D.
Published: January 2008

The present study was carried out to investigate the immune response against Strongyloides venezuelensis infection in Balb/c mice previously immunized with larva‐antigens or primed with live‐larvae. Our results indicate that all primed mice developed a strong protection against challenge infection that remained active for 45 days. In mice primed with live‐larvae the challenge infection resulted in great reduction of migrating larvae and the worms were completely eliminated from the small intestine before maturation. The protection pattern did not alter when the primary infection was aborted by drug treatment. In these experimental groups, the challenge infection was accompanied by a type‐2 predominant immune response, intense IgE and reactive IgG1 production, and granulocyte infiltration in skin, lungs and intestine. The challenge infection in antigen‐immunized mice also resulted in great reduction of migrating larvae. However, the worms that reached the host intestine matured, produced eggs and were eliminated similarly to the ones from nonimmunized mice. Protective mechanisms after immunization with larva antigen were migrating larva‐specific and associated with a strong and mixed Th1 and Th2 response, without tissue granulocyte infiltration. In conclusion, protective immunity induced by a previous infection or antigen‐immunization are stage‐specific and operate through different effector mechanisms.
Gibberellins modulate light signaling pathways to prevent Arabidopsis seedling de‐etiolation in darkness
Authors: Alabadí David , Gallego‐Bartolomé Javier , Orlando Leonardo , García‐Cárcel Laura , Rubio Vicente , Martínez Cristina , Frigerio Martín , Iglesias‐Pedraz Juan Manuel , Espinosa Ana , Deng Xing Wang , Blázquez Miguel A.
Published: January 2008

In many plants, photomorphogenesis is the default developmental program after seed germination, and provides the key features that allow adaptation to light. This program is actively repressed if germination occurs in the absence of light, through a mechanism dependent on the E3 ubiquitin ligase activity that is encoded in Arabidopsis by COP1 (CONSTITUTIVE PHOTOMORPHOGENIC 1), which induces proteolytic degradation of transcription factors necessary for light‐regulated development, such as HY5 (LONG HYPOCOTYL 5) and HYH (LONG HYPOCOTYL 5 HOMOLOG), and stabilization of transcription factors that promote skotomorphogenesis, such as PIF3 (PHYTOCHROME INTERACTING FACTOR 3). Seedlings deficient in gibberellin (GA) synthesis or signaling display a de‐etiolated phenotype when grown in darkness, equivalent to the phenotype of cop1 mutants, which indicates that the switch between photo‐ and skotomorphogenesis is also under hormonal control. Here we provide evidence for the existence of crosstalk between GA and the COP1‐mediated pathway, and identify HY5 and the PIF family as nodes of a regulatory network. This interaction occurs through distinct molecular mechanisms, based on the observation that GA signaling regulates protein stability of HY5, and the activity of PIF3.
Antifungal susceptibility of clinical Candida parapsilosis isolates in Kuwait
Authors: Asadzadeh Mohammad , Al‐Sweih Noura A. , Ahmad Suhail , Khan Zia U.
Published: January 2008

This study presents data on antifungal susceptibility of 114 Candida parapsilosis isolates recovered from clinical specimens in Kuwait. Candida parapsilosis isolates originating from blood (n = 66) and other clinical specimens (n = 48) were tested by Etest against amphotericin B (AP), caspofungin (CS), 5‐flucytosine (FC), fluconazole (FL) and voriconazole (VO). The plates were incubated at 35 °C and readings for minimum inhibitory concentrations (MIC) were recorded after 24 and 48 h of incubation. The MIC ranges and MIC90 read after 48 h were as follows: 0.064–1 and 0.5 μg ml−1 for AP; 0.125–4 and 1.5 μg ml−1 for CS; 0.047 to >256 and 1 μg ml−1 for FL; 0.023 to >32 and 0.125 μg ml−1 for FC and <0.002–1 and 0.047 μg ml−1 for VO respectively. According to Clinical Laboratory Standards Institute criteria, all the isolates were susceptible to VO, and resistance against FC and FL was <2%. Eight (7%) isolates exhibited reduced susceptibility (MIC >1 μg ml−1) to CS including six isolates with MIC of ≥2 μg ml−1 at 48 h reading. The antifungal resistance among bloodstream isolates of C. parapsilosis against AP, FL, FC and VO in Kuwait is rare. This is the first report on CS susceptibility of C. parapsilosis isolates from Arabian Gulf region.
Pulmonary mucormycosis with cervical lymph node involvement in a patient with acute myeloid leukaemia: a case report
Authors: Fanci Rosa , Pecile Patrizia , Di Lollo Simonetta , Dini Catia , Bosi Alberto
Published: January 2008

Here we describe a rare case of pulmonary mucormycosis and simultaneous cervical lymphadenitis in a patient with acute myeloid leukaemia. The patient was successfully treated with liposomal amphotericin B. The diagnosis of Mucor is very difficult, especially in severely immunocompromised patients. This report seems to be the first case about documented lymph node involvement by mucormycosis in humans.
Fiddling while carbon burns: why climate policy needs pervasive emission pricing as well as technology promotion*
Authors: Pezzey John C.V. , Jotzo Frank , Quiggin John
Published: January 2008

Effective climate policy requires global emissions of greenhouse gases to be cut substantially, which can be achieved by energy supply technologies with lower emissions, greater energy use efficiency and substitution in demand. For policy to be efficient requires at least fairly uniform, fairly pervasive emission pricing from taxes, permit trading or combinations of the two; and significant government support for low‐emission technologies. We compare the technology‐focused climate policies adopted by Australia and the ‘Asia–Pacific Partnership on Clean Development and Climate’ (AP6), against this policy yardstick. We find that such policies omit the need for emission pricing to achieve abatement effectively and efficiently; they over‐prescribe which abatement actions should be used most; they make unrealistic assumptions about how much progress can be achieved by voluntarism and cooperation, in the absence of either adequate funding or mandatory policies; and they unjustifiably contrast technology‐focused policy and the Kyoto Protocol approach as the only two policies worth considering, and thus ignore important policy combinations.
Is Australia on a sustainability path? Interpreting the clues*
Authors: Randall Alan
Published: January 2008

Genuine savings is a conceptually valid one‐sided indicator as to whether Australia is on a weak sustainability path (negative GS would warn that current welfare is unsustainable). The World Bank's adjusted net savings (ANS) data summarise the available evidence, and by this indicator Australia is muddling along, at best. ANS misses some important pieces of the picture – net depletion of water, soil and biodiversity, and most kinds of pollution damage – and thus overstates Australia's genuine savings performance. Weak sustainability can be promoted by getting the prices right, and piecemeal efforts are underway via regulatory approaches and resource/environmental markets of various kinds. Nevertheless, particular resource problems – habitat conservation, biodiversity, climate change and dryland salinity – are likely to also require strong sustainability approaches. A sustainable future involves pushing weak sustainability as far as the body politic permits, invoking precautionary instruments for specific resource crises, and nurturing policy processes that encourage the consensus‐building that will be necessary to get it done.
Farms’ technical inefficiencies in the presence of government programs*
Authors: Serra Teresa , Zilberman David , Gil José M.
Published: January 2008

We focus on determining the impacts of government programs on farms’ technical inefficiency levels. We use Kumbhakar's stochastic frontier model that accounts for both production risks and risk preferences. Our theoretical framework shows that decoupled government transfers are likely to increase (decrease) DARA (IARA) farmers’ production inefficiencies if variable inputs are risk decreasing. However, the impacts of decoupled payments cannot be anticipated if variable inputs are risk increasing. We use farm‐level data collected in Kansas to illustrate the model.
The creation of the ISSA and the ILO
Authors: Guinand Cédric
Published: January 2008

Abstract  The creation of the International Social Security Association was strongly influenced by the International Labour Organization, clearly the rising star in the world of international organizations in the period between the two world wars. It would, however, be a mistake to think that the ILO was the only institution to make its voice heard in the establishment of the ISSA. The precursors of the two organizations, the CPIAS and the AIPLT, as well as others active at the time, such as the International Professional Association of Physicians, together with the internationalization of the social insurance movement, helped found this new association, but it faced some difficult moments in its first few years.
Y1 receptors are critical for the proliferation of adult mouse precursor cells in the olfactory neuroepithelium
Authors: Doyle Kharen L , Karl Tim , Hort Yvonne , Duffy Liesl , Shine John , Herzog Herbert
Published: January 2008

While the regenerative capacity of the olfactory neuroepithelium has been well studied less is known about the molecular events controlling precursor cell activity. Neuropeptide Y (NPY) is expressed at high levels in the olfactory system, and NPY has been shown to play a role in neuroregeneration of the brain. In this study, we show that the numbers of olfactory neurospheres derived from NPY, NPY/peptide YY, and Y1 receptor knockout mice are decreased compared with wild type (WT) controls. Furthermore, flow cytometric analysis of isolated horizontal basal cells, globose basal cells, and glandular cells showed that only glandular cells derived from WT mice, but not from NPY and Y1 receptor knockout mice, formed secondary neurospheres suggesting a critical role for NPY signaling in this process. Interestingly, olfactory function tests revealed that olfaction in Y1 knockout mice is impaired compared with those of WT mice, probably because of the reduced number of olfactory neurons formed. Together these results indicate that NPY and the Y1 receptor are required for the normal proliferation of adult olfactory precursors and olfactory function.
Resistance of cell lines to prion toxicity aided by phospho‐ERK expression
Authors: Uppington Kay M. , Brown David R.
Published: January 2008

Prion diseases are fatal neurodegenerative disorders. They are characterised by neuronal loss and the accumulation of an abnormal protein in the CNS. Cell lines exist that express the toxic form of the prion protein (PrP) with little evidence of cell death. Other cell based models studying the mechanism by which cell death occurs employ exogenous application of peptides or fragments of PrP. In this study, we demonstrated that full‐length recombinant PrP binding manganese was toxic to PrP‐expressing cell lines and primary neuronal cultures but not to PrP‐knockout neurones. This toxic form of PrP was also toxic to cell lines equivalently regardless of whether they were infected with scrapie or not. Both scrapie‐infected cells and cells resistant to the toxicity of PrP showed increased levels of phosphorylated ERK protein. Scrapie‐infected cells also showed elevated levels of caspase 12. Inhibition of phospho‐ERK resulted in increased cell death suggesting the increased levels of phospho‐ERK served a protective effect. These results suggest that scrapie‐infected cell lines resist the toxicity of the prions they generate because they produce only low levels of abnormal protein and have increased resistance to apoptotic signs because of heightened activity of the MAP kinase pathway.
Lipidomic analysis of the retina in a rat model of Smith–Lemli–Opitz syndrome: alterations in docosahexaenoic acid content of phospholipid molecular species
Authors: Ford David A. , Monda Julie K. , Brush Richard S. , Anderson Robert E. , Richards Michael J. , Fliesler Steven J.
Published: January 2008

Smith–Lemli–Opitz syndrome (SLOS) is a complex hereditary disease caused by an enzymatic defect in the last step of cholesterol biosynthesis. Progressive retinal degeneration occurs in an AY9944‐induced rat model of SLOS, with biochemical and electroretinographic hallmarks comparable with the human disease. We evaluated alterations in the non‐sterol lipid components of the retina in this model, compared with age‐matched controls, using lipidomic analysis. The levels of 16:0–22:6 and 18:0–22:6 phosphatidylcholine molecular species in retinas were less by > 50% and > 33%, respectively, in rats treated for either 2 or 3 months with AY9944. Relative to controls, AY9944 treatment resulted in > 60% less di‐22:6 and > 15% less 18:0–22:6 phosphatidylethanolamine molecular species. The predominant phosphatidylserine (PS) molecular species in control retinas were 18:0–22:6 and di‐22:6; notably, AY9944 treatment resulted in > 80% less di‐22:6 PS, relative to controls. Remarkably, these changes occurred in the absence of n3 fatty acid deficiency in plasma or liver. Thus, the retinal lipidome is globally altered in the SLOS rat model, relative to control rats, with the most profound changes being less phosphatidylcholine, phosphatidylethanolamine, and PS molecular species containing docosahexaenoic acid (22:6). These findings suggest that SLOS may involve additional metabolic compromise beyond the primary enzymatic defect in the cholesterol pathway.
Hyposialylation of neprilysin possibly affects its expression and enzymatic activity in hereditary inclusion‐body myopathy muscle
Authors: Broccolini Aldobrando , Gidaro Teresa , De Cristofaro Raimondo , Morosetti Roberta , Gliubizzi Carla , Ricci Enzo , Tonali Pietro A. , Mirabella Massimiliano
Published: January 2008

Autosomal recessive hereditary inclusion‐body myopathy (h‐IBM) is caused by mutations of the UDP‐N‐acetylglucosamine 2‐epimerase/N‐acetylmannosamine kinase gene, a rate‐limiting enzyme in the sialic acid metabolic pathway. Previous studies have demonstrated an abnormal sialylation of glycoproteins in h‐IBM. h‐IBM muscle shows the abnormal accumulation of proteins including amyloid‐β (Aβ). Neprilysin (NEP), a metallopeptidase that cleaves Aβ, is characterized by the presence of several N‐glycosylation sites, and changes in these sugar moieties affect its stability and enzymatic activity. In the present study, we found that NEP is hyposialylated and its expression and enzymatic activity reduced in all h‐IBM muscles analyzed. In vitro, the experimental removal of sialic acid by Vibrio Cholerae neuraminidase in cultured myotubes resulted in reduced expression of NEP. This was most likely because of a post‐translational modification consisting in an abnormal sialylation of the protein that leads to its reduced stability. Moreover, treatment with Vibrio Cholerae neuraminidase was associated with an increased immunoreactivity for Aβ mainly in the form of distinct cytoplasmic foci within myotubes. We hypothesize that, in h‐IBM muscle, hyposialylated NEP has a role in hampering the cellular Aβ clearing system, thus contributing to its abnormal accumulation within vulnerable fibers and possibly promoting muscle degeneration.
Loss of cardiolipin in palmitate‐treated GL15 glioblastoma cells favors cytochrome c release from mitochondria leading to apoptosis
Authors: Buratta Morena , Castigli Emilia , Sciaccaluga Miriam , Pellegrino Roberto Maria , Spinozzi Fabrizio , Roberti Rita , Corazzi Lanfranco
Published: January 2008

Unlike oleate and linoleate, palmitate induced mitochondrial apoptosis in GL15 glioblastoma cells. Decrease in membrane potential in a subpopulation of mitochondria of palmitate‐treated cells was revealed using the 5,5′,6,6′‐tetrachloro‐1,1′,3,3′‐tetraethylbenzimidazolylcarbocyanine iodide probe. The diminished ability to reduce a tetrazolium salt indicated an impairment of mitochondrial function. Up to 50% cytochrome c (cyt c) was detached from the inner mitochondrial membrane and released outside mitochondria in palmitate‐treated cells, whereas no release was detected after oleate and linoleate treatments. Cyt c release into the cytosol was followed by caspase 3 activation. Released cyt c and caspase 3 activity were not affected by neutral and acid sphingomyelinase inhibitors and by the inhibitor of serine palmitoyltransferase cycloserine, indicating that apoptosis was independent of the ceramide pathway, nor the mitochondrial pro‐apoptotic AIF or Bcl‐2/Bax factors appeared to be involved in the effect. Utilization of palmitate by GL15 cells altered phospholipid composition. Cardiolipin (CL), the lipid involved in cyt c interaction with the inner mitochondrial membrane, was decreased and highly saturated. This produced an imbalance in hydrophilic/hydrophobic interactions underlying the anchorage of cyt c, by weakening the hydrophobic component and facilitating detachment of the protein and activation of downstream processes. The primary role of CL was explored by supplying GL15 with exogenous CL through a fusion process of CL liposomes with cell plasma membrane. Fused CL moved to mitochondria, as detected by nonylacridine orange probe. Enrichment of mitochondrial membranes with CL prior to palmitate treatment of cells caused decreased cyt c release and caspase 3 activity.
Putative cryptoendolithic life in Devonian pillow basalt, Rheinisches Schiefergebirge, Germany
Authors: PECKMANN J. , BACH W. , BEHRENS K. , REITNER J.
Published: January 2008

Middle Devonian (Givetian) pillow basalt and inter‐pillow breccia from the Rheinisches Schiefergebirge in Germany were found to contain putative biogenic filaments that indicate that life once proliferated within these volcanic rocks. Mineralized filaments are found in carbonate amygdules (vesicles filled by carbonate cement) in the volcanic rock, where they started to form on the internal surface of the once water‐filled vesicles. Biogenicity of the filaments is indicated by (1) their size and shape resembling modern microorganisms including a constant diameter along the length of curved filaments, (2) their independence of crystal faces or cleavage planes, (3) branching patterns reminiscent of modern microorganisms, and (4) their spatial clustering and preferential occurrence close to the margin of pillows and in the inter‐pillow breccias. A time lag between the deposition of pillow basalt and the activity of endoliths is revealed by the sequence of carbonate cements filling the amygdules. The putative filamentous microorganisms thrived after the formation of early fibrous rim cement, but before later equant calcite spar filled most of the remaining porosity. Microbial clay authigenesis analogous to the encrustation of prokaryotes in modern iron‐rich environments led to the preservation of filaments. The filaments predominantly consist of the clay minerals chamosite and illite. Having dwelled in water‐filled vesicles, the Devonian basalt‐hosted filaments apparently represent cryptoendoliths. This finding suggests that a previously unrecognized niche for life exists within volcanic rock.
Growth of synthetic stromatolites and wrinkle structures in the absence of microbes – implications for the early fossil record
Authors: MCLOUGHLIN N. , WILSON L. A. , BRASIER M. D.
Published: January 2008

Stromatolites and wrinkle structures are often taken to be an important indicator for early life. While both may be shaped by microbial mat growth, this can be open to doubt, so that the contribution of abiotic processes in their construction always needs to be established (Grotzinger & Knoll, 1999). We here report laboratory spray deposition experiments that can generate stromatolites and wrinkle structures in the absence of microbes. These minicolumnar and sometimes branched stromatolites are produced artificially by the aggregation of a synthetic colloid in a turbulent flow regime. They self‐organize at the relatively low particle concentrations found in the outer parts of a spray beam. This contrasts with adjacent stratiform deposits that are produced by high rates of colloid deposition and relatively low sediment viscosities found in the centre of a spray beam. These stratiform laminae become subsequently wrinkled during hardening of the colloid. These results support numerical models that together suggest that physicochemical processes are capable of generating laminated sedimentary structures without the direct participation of biology. Geological environments where comparable abiogenic stromatolites and wrinkle structures may be found include: splash‐zone silica sinters, desert varnish crusts and early Archean cherts formed from silica gel precursors.
Inhibitory effects of different ATP‐sensitive potassium channel openers on electrically generated and carbachol‐induced contractions of porcine and human detrusor muscle
Authors: Badawi Jasmin Katrin , Ding Andrea , Bross Stephan
Published: January 2008

The inhibitory effects of different potassium channel openers (PCOs) on electrically generated and carbachol‐induced contractions of porcine and human detrusor muscle were examined. PCOs could be an interesting substance class for treatment of detrusor overactivity. Experiments were performed on muscle strips suspended in a tissue bath. Human tissue originated from patients who underwent total cystectomy. The concentration–relaxation curves of the first‐generation PCOs cromakalim and pinacidil and the untypical PCO minoxidil were performed using carbachol‐precontracted detrusor muscle strips of pigs and humans. Additionally, the inhibitory effects of cromakalim, pinacidil and minoxidil on electrically generated contractions of porcine detrusor muscle were examined. Furthermore, the inhibitory effect of the second‐generation, bladder‐selective PCO ZM 226600 on electrically generated contractions of the human detrusor muscle was determined. Frequency–response curves were performed before and after incubation with one PCO used in two different concentrations. In humans, cromakalim and pinacidil led to a maximum decrease of 73.5 and 68.4% and showed mean pD2 values of 6.65 and 5.5, respectively. In pigs, cromakalim and pinacidil led to a maximum decrease of 90.6 and 93.6% and showed mean pD2 values of 6.39 and 5.01, respectively. Minoxidil did not significantly decrease the precontraction at the highest used concentration in both species. Cromakalim exhibited the biggest inhibitory effect being significant at 10−5 and 10−6 m. Pinacidil showed only a significant inhibitory effect at 10−5 m which was smaller than that of cromakalim. At 3 × 10−6 m only a very small effect occurred at 1 Hz. Minoxidil did not inhibit the contractions at both examined concentrations except for a very small effect at 1 Hz. In humans, ZM 226600 exhibited at 10−6 and 10−5 m a significant inhibitory effect. At 10−7 m it was only significant at one frequency.
Comparative influence of propranolol and verapamil on glycemic control and histamine sensitivity associated with l‐thyroxine‐induced hyperthyroidism – an experimental study
Authors: Bhatt Parloop A. , Makwana Dharmesh
Published: January 2008

The present investigation was undertaken to study the comparative effectiveness of beta‐adrenergic antagonist propranolol and calcium channel blocker verapamil on l‐thyroxine‐induced alteration on glycemic control and histamine sensitivity on rats and guinea pigs, respectively. Injection of l‐thyroxine sodium every alternate day for 3 weeks in guinea pigs (75 μg/kg, i.p.) and rats (75 mg/kg, s.c.) produced a condition similar to thyrotoxicosis. Verapamil and propranolol administered daily in the third week along with l‐thyroxine to two separate groups of hyperthyroid animals reversed thyroxine‐induced loss in body weight, reduction in serum TSH levels, and rise in body temperature. Effect on glucose metabolism and insulin sensitivity was studied on rats. Compared to normal rats, l‐thyroxine‐treated animals showed a state of hyperglycemia, hyperinsulinemia, impaired glucose tolerance, and insulin resistance. Propranolol (10 mg/kg, i.p.) treatment significantly decreased fasting serum glucose levels without affecting serum insulin levels, AUC glucose, and KITT values. Treatment with verapamil (5 mg/kg, i.p.) significantly reduced fasting serum glucose and insulin levels, AUC glucose, and significantly increased KITT values. Effect of propranolol (15 mg/kg, orally) and verapamil (20 mg/kg, orally) treatment on histamine sensitivity was studied on l‐thyroxine‐treated guinea pigs. Compared to normal guinea pigs, l‐thyroxine‐treated guinea pigs showed an increased sensitivity to histamine‐induced asphyxia. Verapamil treatment reversed this increased histamine sensitivity while propranolol aggravated it. In conclusion, compared to propranolol, verapamil has advantageous effects on glucose metabolism, insulin and histamine sensitivity and could therefore be a valuable addition as an adjunctive therapy option currently available for thyrotoxicosis associated with diabetes and/or anaphylaxis.
Gastrointestinal, selective airways and urinary bladder relaxant effects of Hyoscyamus niger are mediated through dual blockade of muscarinic receptors and Ca2+ channels
Authors: Gilani Anwarul Hassan , Khan Arif‐ullah , Raoof Mustafa , Ghayur Muhammad Nabeel , Siddiqui Bina S. , Vohra Waseem , Begum Sabira
Published: January 2008

This study describes the spasmolytic, antidiarrhoeal, antisecretory, bronchodilatory and urinary bladder relaxant properties of Hyoscyamus niger to rationalize some of its medicinal uses. The crude extract of H. niger seeds (Hn.Cr) caused a complete concentration‐dependent relaxation of spontaneous contractions of rabbit jejunum, similar to that caused by verapamil, whereas atropine produced partial inhibition. Hn.Cr inhibited contractions induced by carbachol (1 μm) and K+ (80 mm) in a pattern similar to that of dicyclomine, but different from verapamil and atropine. Hn.Cr shifted the Ca2+ concentration–response curves to the right, similar to that caused by verapamil and dicyclomine, suggesting a Ca2+ channel‐blocking mechanism in addition to an anticholinergic effect. In the guinea‐pig ileum, Hn.Cr produced a rightward parallel shift of the acetylcholine curves, followed by a non‐parallel shift with suppression of the maximum response at a higher concentration, similar to that caused by dicyclomine, but different from that of verapamil and atropine. Hn.Cr exhibited antidiarrhoeal and antisecretory effects against castor oil‐induced diarrhoea and intestinal fluid accumulation in mice. In guinea‐pig trachea and rabbit urinary bladder tissues, Hn.Cr caused relaxation of carbachol (1 μm) and K+ (80 mm) induced contractions at around 10 and 25 times lower concentrations than in gut, respectively, and shifted carbachol curves to the right. Only the organic fractions of the extract had a Ca2+ antagonist effect, whereas both organic and aqueous fractions had anticholinergic effect. A constituent, β‐sitosterol exhibited Ca2+ channel‐blocking action. These results suggest that the antispasmodic effect of H. niger is mediated through a combination of anticholinergic and Ca2+ antagonist mechanisms. The relaxant effects of Hn.Cr occur at much lower concentrations in the trachea and bladder. This study offers explanations for the medicinal use of H. niger in treating gastrointestinal and respiratory disorders and bladder hyperactivity.
Elevated Ras/protein kinase A activity in Saccharomyces cerevisiae reduces proliferation rate and lifespan by two different reactive oxygen species‐dependent routes
Authors: Hlavatá Lydie , Nachin Laurence , Ježek Petr , Nyström Thomas
Published: January 2008

Cells with overactive RAS/protein kinase A (PKA) signaling, such as RAS2Val19 cells, exhibit reduced proliferation rates and accelerated replicative senescence. We show here that the extended generation time of RAS2Val19cells is the result of abrogated ATP/ADP carrier activity of the mitochondria. Both PKA‐dependent and independent routes are responsible for inhibiting ATP/ADP exchange in the RAS‐overactive cells. The reduced carrier activity is due, at least in part, to elevated levels of reactive oxygen species (ROS), which also cause a proteolysis‐dependent fragmentation of the Aac2p carrier both in vivo and on isolated mitochondria. Attenuated carrier activity is suppressed by overproducing the superoxide dismutase, Sod1p, and this enhances both the proliferation rate and the replicative longevity of RAS2Val19 cells. In contrast, overproducing functional Aac2p restored proliferation but not longevity of RAS2Val19 cells. Thus, Ras signaling affects proliferation rate and replicative lifespan by two different, ROS‐dependent, routes. While the reduction in generation time is linked to the inactivation, specifically, of the mitochondrial nucleotide carrier, longevity is affected by other, and hitherto unknown, target(s) of ROS attack.
Role of dFOXO in lifespan extension by dietary restriction in Drosophila melanogaster: not required, but its activity modulates the response
Authors: Giannakou Maria E. , Goss Martin , Partridge Linda
Published: January 2008

Dietary restriction (DR) increases lifespan in diverse organisms. However, the mechanisms by which DR increases survival are unclear. The insulin/IGF‐like signaling (IIS) pathway has been implicated in the response to DR in some studies, while in others it has appeared to play little or no role. We used the fruitfly Drosophila melanogaster to investigate the responses to DR of flies mutant for the transcription factor dFOXO, the main transcription factor target of IIS. We found that lifespan extension by DR does not require dFOXO. However, flies with dFOXO overexpressed in the adult fat body showed an altered response to DR and behaved as though partially dietarily restricted. These results suggest that, although DR extends lifespan of flies in the absence of dFOXO, the presence of active dFOXO modulates the response to DR, possibly by modifying expression of its target genes, and may therefore mediate the normal response to DR.
Plasticity of hippocampal stem/progenitor cells to enhance neurogenesis in response to kainate‐induced injury is lost by middle age
Authors: Hattiangady Bharathi , Rao Muddanna S. , Shetty Ashok K.
Published: January 2008

A remarkable up‐regulation of neurogenesis through increased proliferation of neural stem/progenitor cells (NSCs) is a well‐known plasticity displayed by the young dentate gyrus (DG) following brain injury. To ascertain whether this plasticity is preserved during aging, we quantified DG neurogenesis in the young adult, middle‐aged and aged F344 rats after kainic acid induced hippocampal injury. Measurement of new cells that are added to the dentate granule cell layer (GCL) between post‐injury days 4 and 15 using 5′‐bromodeoxyuridine labeling revealed an increased addition of new cells in the young DG but not in the middle‐aged and aged DG. Quantification of newly born neurons using doublecortin immunostaining also demonstrated a similar trend. Furthermore, the extent of ectopic migration of new neurons into the dentate hilus was dramatically increased in the young DG but was unaltered in the middle‐aged and aged DG. However, there was no change in neuronal fate‐choice decision of newly born cells following injury in all age groups. Similarly, comparable fractions of new cells that are added to the GCL after injury exhibited 5‐month survival and expressed the mature neuronal marker NeuN, regardless of age or injury at the time of their birth. Thus, hippocampal injury does not adequately stimulate NSCs in the middle‐aged and aged DG, resulting in no changes in neurogenesis after injury. Interestingly, rates of both neuronal fate‐choice decision and long‐term survival of newly born cells remain stable with injury in all age groups. These results underscore that the ability of the DG to increase neurogenesis after injury is lost as early as middle age.
ARCHAEOMETRICAL STUDIES OF ROMAN IMPERIAL AGE GLASS FROM CANTON TICINO*
Authors: ARLETTI R. , VEZZALINI G. , BIAGGIO SIMONA S. , MASELLI SCOTTI F.
Published: January 2008

An archaeometrical study of Roman glass finds recovered in the Canton Ticino area was performed after the finding of traces of possible glass‐working at Muralto near Locarno. The aim of this work is to provide chemical characterization of these glass varieties—never analysed before—and to compare the results obtained with those for glass of the same period coming from other sites (Aquileia, Augusta Praetoria and Modena). The chemical data shows that the composition of Canton Ticino glass remained the same from the first to the fourth century ad. Moreover, the large amounts of Sb used as a decolouring agent in these samples represents a peculiar trait.
ACCESSING PAST BELIEFS AND PRACTICES: THE CASE OF LEMNIAN EARTH*
Authors: HALL A. J. , PHOTOS‐JONES E.
Published: January 2008

Lemnian Earth, a medicine in the shape of a stamped clay tablet (sphragis) from Lemnos, northeastern Greece, was much valued in antiquity and in the post‐medieval period as an antidote to poison and a treatment for other ailments. Although it was among the first archaeological materials to be subjected to chemical analysis (in 1807), there is still no clear understanding as to what made Lemnian Earth an effective medicine. We argue that Lemnian Earth, the artefact, was not the same as Lemnian Earth, the raw material. We suggest a composition for the artefact by scrutinizing the documentary evidence for its properties and by considering the geochemical processes that led to the formation of the raw material and the ritual relating to its extraction. The study of the latter highlights the need for archaeological materials scientists to recognize ritual as a possible manifestation of physical and chemical processes carried out within the framework of past beliefs and practices.
The Effect of Bank Credit on Asset Prices: Evidence from the Japanese Real Estate Boom during the 1980s
Authors: MORA NADA
Published: January 2008

This paper studies whether bank credit fuels asset prices. Financial deregulation during the 1980s allowed keiretsus to obtain finance publicly and reduce their dependence on banks. Banks that lost these blue‐chip customers increased their property lending, and serve as an instrument for the supply of real estate loans. Using this instrument, I find that a 0.01 increase in a prefecture's real estate loans as a share of total loans causes 14–20% higher land inflation compared with other prefectures over the 1981–91 period. The timing of losses of keiretsu customers also coincides with subsequent land inflation in a prefecture.
The “Great Moderation” in the United Kingdom
Authors: BENATI LUCA
Published: January 2008

We use a Bayesian time‐varying parameters structural VAR with stochastic volatility for GDP deflator inflation, real GDP growth, a 3‐month nominal rate, and the rate of growth of M4 to investigate the underlying causes of the Great Moderation in the United Kingdom. Our evidence points toward a dominant role played by good luck in fostering the more stable macroeconomic environment of the last two decades. Results from counterfactual simulations, in particular, show that (i) “bringing the Monetary Policy Committee back in time” would only have had a limited impact on the Great Inflation episode, at the cost of lower output growth; (ii) imposing the 1970s monetary rule over the entire sample period would have made almostnodifference in terms of inflation and output growth outcomes; and (iii) the Great Inflation was due, to a dominant extent, to large demand non‐policy shocks, and to a lesser extent—especially in 1973 and 1979—to supply shocks.
Magnetic‐Guided Percutaneous Coronary Intervention Enabled by Two‐Dimensional Guidewire Steering and Three‐Dimensional Virtual Angioscopy: Initial Experiences in Daily Clinical Practice
Authors: SCHNEIDER MICHAEL A. E. , HOCH FRANZ V. , NEUSER HANS , BRUNN JÜRGEN , KOLLER MARCUS L. , GIETZEN FRANK , SCHAMBERGER RAINER , KERBER SEBASTIAN , SCHUMACHER BURGHARD
Published: January 2008

Aims:

Percutaneous coronary intervention (PCI) has been broadly established and often includes highly complex stenoses that require difficult navigation. The purpose of this study is to assess the feasibility of a new magnetic navigation system (MNS) to enable intracoronary guidewire deployment and PCI in daily clinical practice and to compare the 2D guidance to the virtual 3D angioscopy feature.

Methods and Results:

We included 30 consecutive patients (pt) in whom 36 coronary arteries were PCI targets. Patients were randomized to guidewire steering by either 2D guidance or virtual 3D angioscopy (33%).

In 31/36 (86%) interventions the MNS guidewire successfully passed the culprit stenosis and the procedure was accomplished by PCI. In 5/30 pt an MNS multivessel intervention was performed. Three of 5 unsuccessful procedures failed due to an unsuccessful recanalization of a subtotal chronic occlusion including 1 pt who required surgical intervention. In 2/36 procedures the magnetic guided intervention was performed effectively after prior conventional failure related to complex anatomy. The contrast medium amount needed to position the magnetic guidewire was 60 ± 101 mL in 2D accomplished interventions vs. 14 ± 15 mL in 3D procedures (p < 0.05). In 3 pt the MNS did not harm the implanted pacemaker or defibrillator system.

Conclusion:

Magnetic guided PCI is useful in selected patients. In our experience, success is less likely in evidence of a subtotal occlusion.