bluuebunny/crossref_metadata_2025 huggingface dataset:
A transcription-dependent mechanism, akin to that in adipose tissue, modulates lipoprotein lipase activity in rat heart
Authors: Wu Gengshu , Zhang Liyan , Gupta Jitendra , Olivecrona Gunilla , Olivecrona Thomas
Published: June 2007

The enzyme lipoprotein lipase (LPL) releases fatty acids from lipoprotein triglycerides for use in cell metabolism. LPL activity is rapidly modulated in a tissue-specific manner. Recent studies have shown that in rat adipose tissue this occurs by a shift of extracellular LPL toward an inactive form catalyzed by an LPL-controlling protein whose expression changes in response to the nutritional state. To explore whether a similar mechanism operates in other tissues we injected actinomycin D to block transcription of the putative LPL controlling protein(s). When actinomycin was given to fed rats, heparin-releasable LPL activity increased by 160% in heart and by 150% in a skeletal muscle (soleus) in 6 h. Postheparin LPL activity in blood increased by about 200%. To assess the state of extracellular LPL we subjected the spontaneously released LPL in heart perfusates to chromatography on heparin-agarose, which separates the active and inactive forms of the lipase. The amount of lipase protein released remained relatively constant on changes in the nutritional state and/or blockade of transcription, but the distribution between the active and inactive forms changed. Less of the LPL protein was in the active form in perfusates from hearts from fed compared with fasted rats. When glucose was given to fasted rats the proportion of LPL protein in the active form decreased. Actinomycin D increased the proportion that was active, in accord with the hypothesis that the message for a rapidly turning over LPL-controlling protein was being removed.
Angiotensin II stimulates the reactivity of the pituitary-adrenal axis in leptin-resistant Zucker rats, thereby influencing the glucose utilization
Authors: Müller Helge , Schweitzer Nora , Jöhren Olaf , Dominiak Peter , Raasch Walter
Published: June 2007

The HPA axis is hyperactive under conditions of leptin and insulin resistance as well as after ANG II administration. We hypothesized that a hyperreactivity of the HPA axis to ANG contributes to an impaired glucose utilization in obesity, since leptin resistance and an overactive renin-angiotensin-aldosterone system are features of obesity. Zucker rats were treated with ANG via subcutaneous minipumps (0, 0.9, and 9.0 μg/h; 4 wk). PA axis reactivity and glucose homeostasis were characterized after CRH treatment and during an oral glucose tolerance test (OGTT). The elevated plasma profile of corticosterone after CRH stimulation in saline-treated OZR compared with LZR confirmed that the sensitization of the PA axis depended on leptin resistance. Irrespective of the rat strain, circulating ANG levels and blood pressure were selectively increased after administration of 9 μg/h ANG (high ANG). Only high ANG induced an elevation of the corticosterone and glucose response after CRH stimulation in OZR but did not affect the ACTH secretion. During OGTT, corticosterone and consequently glucose increased in OZR after high ANG, whereas the insulin secretion was decreased. In the adrenal glands of OZR, AT1A receptor mRNA levels increased after high ANG. We conclude that the impairment of glucose utilization after ANG stimulation is potentiated in leptin-resistant rats as a result of a hyperreactive PA axis, thereby confirming the functional importance of a dysregulation within the HPA axis in metabolic syndrome or obesity. The ACTH-independent stimulation of corticosterone release and the selective increase of AT1A receptor mRNA in the adrenals of OZR indicated a sensitization of adrenals toward ANG, causing a stimulation of the PA axis.
Effects of ghrelin administration on decreased growth hormone status in obese animals
Authors: Iwakura Hiroshi , Akamizu Takashi , Ariyasu Hiroyuki , Irako Taiga , Hosoda Kiminori , Nakao Kazuwa , Kangawa Kenji
Published: June 2007

Obesity is characterized by markedly decreased ghrelin and growth hormone (GH) secretion. Ghrelin is a GH-stimulating, stomach-derived peptide that also has orexigenic action. Ghrelin supplement may restore decreased GH secretion in obesity, but it may worsen obesity by its orexigenic action. To reveal effects of ghrelin administration on obese animals, we first examined acute GH and orexigenic responses to ghrelin in three different obese and/or diabetic mouse models: db/db mice, mice on a high-fat diet (HFD mice), and Akita mice for comparison. GH responses to ghrelin were significantly suppressed in db/db, HFD, and Akita mice. Food intake of db/db and Akita mice were basally higher, and further stimulation of food intake by ghrelin was suppressed. Pituitary GH secretagogue receptor mRNA levels in db/db and HFD mice were significantly decreased, which may partly contribute to decreased GH response to ghrelin in these mice. In Akita mice for comparison, decreased hypothalamic GH-releasing hormone (GHRH) mRNA levels may be responsible for decreased GH response, since maximum GH response to ghrelin needs GHRH. When ghrelin was injected into HFD mice with GHRH coadministrated, GH responses to ghrelin were significantly emphasized. HFD mice injected with low-dose ghrelin and GHRH for 10 days did not show weight gain. These results indicate that low-dose ghrelin and GHRH treatment may restore decreased GH secretion in obesity without worsening obesity.
Curcumin Derivatives Inhibit or Modulate Beta-Amyloid Precursor Protein Metabolism
Authors: Narlawar Rajeshwar , Baumann Karlheinz , Schubenel Robert , Schmidt Boris
Published: June 2007

Curcumin-derived oxazoles and pyrazoles were synthesized in order to minimize the metal chelation properties of curcumin. The reduced rotational freedom and the absence of stereoisomers was anticipated to enhance the inhibition of γ-secretase. Accordingly, the replacement of the 1,3-dicarbonyl moiety by isosteric heterocycles turned curcumin analogue oxazoles and pyrazoles into potent γ-secretase inhibitors. Compounds 4a-i were found to be potent inhibitors of γ-secretase and displayed activity in the low micromolar range.
Receptor- and Non-Receptor Tyrosine Kinases Induce Processing of the Amyloid Precursor Protein: Role of the Low-Density Lipoprotein Receptor-Related Protein
Authors: Minopoli Giuseppina , Passaro Fabiana , Aloia Luigi , Carlomagno Francesca , Melillo Rosa Marina , Santoro Massimo , Forzati Floriana , Zambrano Nicola , Russo Tommaso
Published: June 2007

The Alzheimer’s β-amyloid peptides derive from the proteolytic processing of the β-amyloid precursor protein, APP, by β- and γ-secretases. The regulation of this processing is not fully understood. Experimental evidence suggests that the activation of pathways involving protein tyrosine kinases, such as PDGFR and Src, could induce the cleavage of APP and in turn the generation of amyloid peptides. In this paper we addressed the effect of receptor and nonreceptor protein tyrosine kinases on the cleavage of APP and the mechanisms of their action. To this aim, we developed an in vitro system based on the APP-Gal4 fusion protein stably transfected in SHSY5Y neuroblastoma cell line. The cleavage of this molecule, induced by various stimuli, results in the activation of the transcription of the luciferase gene under the control of Gal4 cis-elements. By using this experimental system we demonstrated that, similarly to Src, three tyrosine kinases, TrkA, Ret and EGFR, induced the cleavage of APP-Gal4. We excluded that this effect was mediated by the activation of Ras-MAPK, PI3K-Akt and PLC-γ pathways. Furthermore, the direct phosphorylation of the APP cytosolic domain does not affect Aβ peptide generation. On the contrary, experiments in cells lacking the LDL-receptor related protein LRP support the hypothesis that the interaction of APP with LRP is required for the induction of APP cleavage by tyrosine kinases.
BACE1 Expression and Activity: Relevance in Alzheimer’s Disease
Authors: Zacchetti Daniele , Chieregatti Evelina , Bettegazzi Barbara , Mihailovich Marija , Sousa Vitor Lino , Grohovaz Fabio , Meldolesi Jacopo
Published: June 2007

A turning point of research in Alzheimer’s disease was undoubtedly the discovery of BACE1, the amyloid-β precursor protein-cleaving enzyme that initiates the generation of amyloid-β, the peptide strongly suspected to be responsible for neuronal malfunction and death. Several research groups started a race to identify the best inhibitor of BACE1 activity. On the other hand, basic researchers are evaluating the changes in BACE1 expression and activity with the aim to better understand the pathogenetic process of the disease. Along this second line of research, in the last few years many important results have been reported in various experimental models, as well as in Alzheimer’s disease patients. As a consequence, new pathogenetic paradigms have been developed. We have reviewed these reports trying to highlight contrasting viewpoints, data awaiting final confirmation, and promising perspectives.
Peripheral Site Acetylcholinesterase Blockade Induces RACK1-Associated Neuronal Remodeling
Authors: Farchi Noa , Ofek Keren , Podoly Erez , Dong Haiheng , Xiang Yun-Yan , Diamant Sophia , Livnah Oded , Li Jingxin , Hochner Binyamin , Lu Wei-Yang , Soreq Hermona
Published: June 2007

Background: Peripheral anionic site (PAS) blockade of acetylcholinesterase (AChE) notably affects neuronal activity and cyto-architecture, however, the mechanism(s) involved are incompletely understood. Objective: We wished to specify the PAS extracellular effects on specific AChE mRNA splice variants, delineate the consequent cellular remodeling events, and explore the inhibitory effects on interchanging RACK1 interactions. Methods: We exposed rat hippocampal cultured neurons to BW284C51, the peripheral anionic site inhibitor of AChE, and to the non-selective AChE active site inhibitor, physostigmine for studying the neuronal remodeling of AChE mRNA expression and trafficking. Results: BW284C51 induced overexpression of both AChE splice variants, yet promoted neuritic translocation of the normally rare AChE-R, and retraction of AChE-S mRNA in an antisense-suppressible manner. BW284C51 further caused modest decreases in the expression of the scaffold protein RACK1 (receptor for activated protein kinase βII), followed by drastic neurite retraction of both RACK1 and the AChE homologue neuroligin1, but not the tubulin-associated MAP2 protein. Accompanying BW284C51 effects involved decreases in the Fyn kinase and membrane insertion of the glutamate receptor NR2B variant and impaired glutamatergic activities of treated cells. Intriguingly, molecular modeling suggested that direct, non-catalytic competition with Fyn binding by the RACK1-interacting AChE-R variant may be involved. Conclusions: Our findings highlight complex neuronal AChE-R/RACK1 interactions and are compatible with the hypothesis that peripheral site AChE inhibitors induce RACK1-mediated neuronal remodeling, promoting suppressed glutamatergic neurotransmission.
Frequency of the LRRK2 G2019S Mutation in Siblings with Parkinson’s Disease
Authors: Lesage Suzanne , Leclere Laurence , Lohmann Ebba , Borg Michel , Ruberg Merle , Dürr Alexandra , Brice Alexis
Published: June 2007

Background: Mutations in the LRRK2 gene, the most frequent of which is the G2019S mutation in exon 41, cause familial and sporadic Parkinson’s disease (PD) with reduced penetrance. Objectives: To assess the frequency of the LRRK2 G2019S mutation in families thought to have autosomal recessive PD (siblings but not their parents were affected) and to determine the clinical features of LRRK2 mutation carriers. Methods: We sequenced both strands of exon 41 of the LRKK2 gene in 90 index cases from French and North African families in which PD might have been inherited as a recessive trait. Patients with mutations underwent detailed clinical evaluations. Results: We found heterozygous G2019S mutations in 1 Algerian and 1 French family (overall relative frequency = 2.2%). Four LRRK2-positive patients had typical PD, but their Mini Mental State Examination (MMSE) scores were lower than those of patients without this mutation. Conclusion: The LRRK2 G2019S mutation is as frequent in families with possible autosomal recessive PD (2.2%) as in the sporadic cases published elsewhere (1.9%). The clinical features in the LRRK2-positive patients were those of typical PD, except for lower MMSE scores.
Frontotemporal Dementia with Tau Pathology
Authors: Gasparini Laura , Terni Beatrice , Spillantini Maria Grazia
Published: June 2007

Tau is a microtubule-associated protein involved in microtubule assembly and stabilization. Filamentous deposits made of tau constitute a major defining characteristic of several neurodegenerative diseases known as tauopathies including Alzheimer’s disease. The involvement of tau in neurodegeneration has been clarified by the identification of genetic mutations in the tau gene in cases with familial frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17). Although the mechanism through which tau mutations lead to neuronal death is still unresolved, it is clear that tau mutations lead to formation of tau filaments that have a different morphology, contain different types of tau isoforms and produce distinct tau deposits. The range of tau pathology identified in FTDP-17 recapitulates the tau pathology present in sporadic tauopathies and indicates that tau dysfunction plays a major role also in these diseases.
Small Molecule Inducers of Heat-Shock Response Reduce polyQ-Mediated Huntingtin Aggregation
Authors: Herbst Martin , Wanker Erich E.
Published: June 2007

Enhancing cellular defense mechanisms against different kinds of stress may be an attractive therapeutic strategy for neurodegenerative diseases. In particular, inducing the expression of molecular chaperones might reduce the formation of misfolded proteins and toxic aggregates that occur in polyglutamine (polyQ) disorders such as Huntington’s disease. Geldanamycin, a natural substance that modulates Hsp90 function, was previously shown to induce a heat-shock response and to reduce polyQ aggregation in mammalian cells. However, because of toxic and unfavorable pharmacokinetic properties, geldanamycin is not suitable for clinical use. In this study we evaluated the effects of the pharmacologically improved geldanamycin derivatives 17-DMAG and 17-AAG on polyQ aggregation in mammalian cells. Quantitative RT-PCR and SDS-PAGE experiments revealed that 17-DMAG induces expression of the molecular chaperones Hsp40, Hsp70, and Hsp105 in mammalian cells and inhibits the formation of mutant huntingtin aggregates with higher efficiency than 17-AAG or geldanamycin itself. Induction of a heat-shock response and inhibition of polyQ aggregation occurred at nanomolar concentrations. We suggest that geldanamycin derivatives such as 17-DMAG should be considered for the development of a drug treatment for polyQ disorders and other neurodegenerative diseases involving protein aggregation.
Elimination of Lipid Peroxide during Hemodialysis
Authors: Obara Mami , Hirayama Aki , Gotoh Michihiro , Ueda Atsushi , Ishizu Takashi , Taru Yoshinori , Shimozawa Yukari , Yamagata Kunihiro , Nagase Sohji , Koyama Akio
Published: June 2007

Background/Aims: This study is aimed to show the antioxidative effect of hemodialysis (HD) by demonstrating the elimination of toxic lipid peroxides. Methods: Blood samples were obtained from patients on regular maintenance HD before and 15, 30, 60, 120 and 240 min after the start of each HD session. Plasma cholesteryl ester hydroperoxide (CE-OOH), phosphatidylcholine hydroperoxide (PC-OOH), and eliminators of lipid peroxides (LOOH) such as apolipoprotein A-I (apoA-I) and lecithin:cholesterol acyltransferase (LCAT) were investigated. The hydroxyl radical scavenging activity was measured for the evaluation of the pro-oxidative side. Results: CE-OOH and PC-OOH were elevated in patients with chronic kidney disease both on and not on HD, while these values were much higher in HD patients. CE-OOH quickly dropped during the first 30 min of HD, then gradually decreased until 240 min. CE-OOH concentrations were related to those of apoA-I. In contrast, PC-OOH showed an increase 30 min after the start of HD, a change which resembled that of LCAT and was the reverse of the hydroxyl radical scavenging activity. Conclusion: These results demonstrate the antioxidative action through CE-OOH elimination involving apoA-I. The pro- and antioxidative effects of HD on LOOH are not uniform but PC-OOH is mainly influenced prooxidatively.
Secondary Torsion of Vermiform Appendix with Mucinous Cystadenoma
Authors: Kitagawa Maki , Kotani Tatsuya , Yamano Takeshi , Tsurudome Hideaki , Hatakeyama Tomoya , Kuriu Yoshiaki , Nishi Hiroshi , Yabe Masaharu
Published: June 2007

Torsion of the vermiform appendix is a rare disorder, which causes abdominal symptoms indistinguishable from acute appendicitis. We report a case (a 34-year-old male) of secondary torsion of the vermiform appendix with mucinous cystadenoma. This case was characterized by mild inflammatory responses, pentazocine-resistant abdominal pain, and appendiceal tumor, which was not enhanced by the contrast medium on computed tomography presumably because of reduced blood flow by the torsion. These findings may be helpful for the preoperative diagnosis of secondary appendiceal torsion.
Clinicopathological Parameters and Expression of P-Glycoprotein and MRP-1 in Retinoblastoma
Authors: Kamburoğlu Günhal , Kiratli Hayyam , Söylemezoğlu Figen , Bilgiç Sevgül
Published: June 2007

Purpose: The immunohistochemical expressions of two multidrug resistance proteins, P-glycoprotein (P-gp) and multidrug resistance-related protein-1 (MRP-1), were studied in retinoblastoma and the correlations with the clinicopathological parameters were assessed. Method: Sixty-five enucleated eyes containing retinoblastoma were included in the study. Following hematoxylin-eosin staining, tumor differentiation, presence of choroidal invasion, optic nerve invasion, retinal invasion, necrosis and presence of calcification were evaluated with the light microscope. P-gp and MRP-1 expressions were evaluated immunohistochemically. Results: Fifty-three eyes were enucleated primarily and 12 eyes were operated after failure of chemotherapy. P-gp and MRP-1 expressions were positive in 69.3 and 73.4% of specimens, respectively. There was no statistically significant relationship between the expressions of P-gp and MRP-1, and tumor differentiation, presence of tumor invasion or treatment with chemotherapy. Conclusion: Retinoblastoma intrinsically expresses both P-gp and MRP-1 and their expressions are not related to tumor differentiation. The expressions of P-gp and MRP-1 do not seem to be induced by chemotherapy and are not related to the degree of tumor invasion.
Poly(ADP-Ribose) Polymerase Offers Protection against Oxidative and Alkylation Damage to the Nuclear and Mitochondrial Genomes of the Retinal Pigment Epithelium
Authors: Jarrett Stuart G. , Boulton Michael E.
Published: June 2007

Purpose: To investigate the role of poly(ADP-ribose)-polymerase (PARP) in protecting against oxidative (H2O2) and alkylation (MMS) damage to the nDNA and mtDNA genomes of the retinal pigment epithelium (RPE). We further hypothesized that PARP ribosylation enzymatic activity is required to facilitate efficient nDNA and mtDNA repair to enable the RPE to survive chronic oxidative stress exposure. Methods: Cellular sensitivity to H2O2 and MMS was determined by the MTT and LDH assays. PARP ribosyl(ation) activity was inhibited by supplementation of 3-aminobenzamide (competitive PARP inhibitor). The susceptibility and repair capacities of nuclear and mitochondrial genomes were assessed by quantitative PCR and PARP activity assessed using an enzyme assay. Results: This study demonstrated that cells lacking ribosyl(ation) activity had a significantly lower lesion repair capacity in both nDNA and mtDNA (p < 0.05), which culminated in reduced cell viability after H2O2 exposure only (p < 0.05). Furthermore, the mtDNA demonstrated a significantly greater sensitivity compared to nDNA to both oxidative and alkylation damage (p < 0.05). Conclusion: PARP activity has an important role in providing the RPE with the high oxidative tolerance required for this cell type to survive the constant reactive oxygen species attack in vivo for several decades.
Liver Resection or Combined Chemoembolization and Radiofrequency Ablation Improve Survival in Patients with Hepatocellular Carcinoma
Authors: Helmberger Thomas , Dogan Selin , Straub Gundula , Schrader Angelika , Jüngst Christoph , Reiser Maximilian , Waggershauser Tobias , Jakobs Tobias , Hoffmann Ralf-Thorsten , Löhe Florian , Graeb Christian , Rau Horst-Günter , Schauer Rolf , Jauch Karl-Walter , Caselmann Wolfgang H. , Göke Burkhard , Jüngst Dieter
Published: June 2007

Background/Aims: To evaluate the long-term outcome of surgical and non-surgical local treatments of patients with hepatocellular carcinoma (HCC). Methods: We stratified a cohort of 278 HCC patients using six independent predictors of survival according to the Vienna survival model for HCC (VISUM-HCC). Results: Prior to therapy, 224 HCC patients presented with VISUM stage 1 (median survival 18 months) while 29 patients were classified as VISUM stage 2 (median survival 4 months) and 25 patients as VISUM stage 3 (median survival 3 months). A highly significant (p < 0.001) improved survival time was observed in VISUM stage 1 patients treated with liver resection (n = 52; median survival 37 months) or chemoembolization (TACE) and subsequent radiofrequency ablation (RFA) (n = 44; median survival 45 months) as compared to patients receiving chemoembolization alone (n = 107; median survival 13 months) or patients treated by tamoxifen only (n = 21; median survival 6 months). Chemoembolization alone significantly (p ≤ 0.004) improved survival time in VISUM stage 1–2 patients but not (p = 0.341) in VISUM stage 3 patients in comparison to those treated by tamoxifen. Conclusion: Both liver resection or combined chemoembolization and RFA improve markedly the survival of patients with HCC.
Voluntary Exercise Impacts on the Rat Hypothalamic-Pituitary-Adrenocortical Axis Mainly at the Adrenal Level
Authors: Droste Susanne K. , Chandramohan Yalini , Hill Louise E. , Linthorst Astrid C.E. , Reul Johannes M.H.M.
Published: June 2007

Introduction: Evidence is accumulating that the regular performance of exercise is beneficial for stress coping. However, the hypothalamic-pituitary-adrenocortical (HPA) axis of voluntarily exercising rats has never been comprehensively investigated. Methods: Therefore, male Sprague-Dawley rats were given access to a running wheel in their home cage for 4 weeks in which they ran 4–7 km per night. Results: After 4 weeks, the exercising animals showed significantly less body weight gain, less abdominal fat tissue, decreased thymus weight, and increased adrenal weight (relative to body weight). Furthermore, tyrosine hydroxylase (TH) mRNA levels were selectively increased in the right adrenal me- dulla indicating an increase in sympathoadrenomedullary capacity in exercising rats. No changes were observed in paraventricular corticotropin-releasing hormone (CRH), arginine-vasopressin (AVP) and oxytocin mRNA levels. Mineralocorticoid receptor (MR) mRNA levels in hippocampus and glucocorticoid receptor (GR) mRNA levels in frontal cortex, parvocellular paraventricular nucleus and anterior pituitary were unchanged, whereas GR mRNA levels were increased in distinct hippocampal cell layers. Early morning baseline levels of plasma ACTH and corticosterone were similar in both groups. Interestingly, the response to different stressful stimuli (e.g. forced swimming, novelty) revealed that the exercising rats showed stressor-specific changes in HPA hormone responses. Forced swimming evoked a markedly enhanced response in corticosterone levels in the exercising rats. In contrast, if rats were exposed to a novel environment, exercising rats showed a much lower response in corticosterone than the control animals. However, the response in ACTH to either stressor was comparable between groups. Thus, in exercising rats physically demanding stressors evoke enhanced glucocorticoid responses whereas mild psychologically stressful stimuli such as novelty result in an attenuated glucocorticoid response. Interestingly, this attenuated hormone response corresponded with the observation that the exercising rats showed less anxious behaviour in the novelty situation. Conclusions: The differential responses in plasma corticosterone levels to different types of stress in the face of comparable responses in ACTH levels underscore the existence of critical regulatory control mechanisms at the level of the adrenal gland. We have hypothesized that changes in the sympathoadrenomedullary input may play an important role in these distinct glucocorticoid responses to stress. Our previous studies have shown similar changes in voluntarily exercising mice. Therefore, we conclude that the effects of exercise on the organism are not species-specific. Thus, our observations may have translational implications for the human situation.
Copula-Derived Observation Operators for Assimilating TMI and AMSR-E Retrieved Soil Moisture into Land Surface Models
Authors: Gao Huilin , Wood Eric F. , Drusch Matthias , McCabe Matthew F.
Published: June 2007

Assimilating soil moisture from satellite remote sensing into land surface models (LSMs) has potential for improving model predictions by providing real-time information at large scales. However, the majority of the research demonstrating this potential has been limited to datasets based on either airborne data or synthetic observations. The limited availability of satellite-retrieved soil moisture and the observed qualitative difference between satellite-retrieved and modeled soil moisture has posed challenges in demonstrating the potential over large regions in actual applications. Comparing modeled and satellite-retrieved soil moisture fields shows systematic differences between their mean values and between their dynamic ranges, and these systematic differences vary with satellite sensors, retrieval algorithms, and LSMs. This investigation focuses on generating observation operators for assimilating soil moisture into LSMs using a number of satellite–model combinations. The remotely sensed soil moisture products come from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and the NASA/Earth Observing System (EOS) Advanced Microwave Scanning Radiometer (AMSR-E). The soil moisture model predictions are from the Variable Infiltration Capacity (VIC) hydrological model; the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40); and the NCEP North American Regional Reanalysis (NARR). For this analysis, the satellite and model data are over the southern Great Plains region from 1998 to 2003 (1998–2002 for ERA-40). Previous work on observation operators used the matching of cumulative distributions to transform satellite-retrieved soil moisture into modeled soil moisture, which implied perfect correlations between the ranked values. In this paper, a bivariate statistical approach, based on copula distributions, is employed for representing the joint distribution between retrieved and modeled soil moisture, allowing for a quantitative estimation of the uncertainty in modeled soil moisture when merged with a satellite retrieval. The conditional probability distribution of model-based soil moisture conditioned on a satellite retrieval forms the basis for the soil moisture observation operator. The variance of these conditional distributions for different retrieval algorithms, LSMs, and locations provides an indication of the information content of satellite retrievals in assimilation. Results show that the operators vary by season and by land surface model, with the satellite retrievals providing more information in summer [July–August (JJA)] and fall [September–November (SON)] than winter [December–February (DJF)] or spring [March–May (MAM)] seasons. Also, the results indicate that the value of satellite-retrieved soil moisture is most useful to VIC, followed by ERA-40 and then NARR.
Uncertainty Assessment of Future Hydroclimatic Predictions: A Comparison of Probabilistic and Scenario-Based Approaches
Authors: Koutsoyiannis D. , Efstratiadis A. , Georgakakos K. P.
Published: June 2007

During the last decade, numerous studies have been carried out to predict future climate based on climatic models run on the global scale and fed by plausible scenarios about anthropogenic forcing to climate. Based on climatic model output, hydrologic models attempt then to predict future hydrologic regimes at regional scales. Much less systematic work has been done to estimate climatic uncertainty and to assess the climatic and hydrologic model outputs within an uncertainty perspective. In this study, a stochastic framework for future climatic uncertainty is proposed, based on the following lines: 1) climate is not constant but rather varying in time and expressed by the long-term (e.g., 30 yr) time average of a natural process, defined on a finescale; 2) the evolution of climate is represented as a stochastic process; 3) the distributional parameters of a process, marginal and dependence, are estimated from an available sample by statistical methods; 4) the climatic uncertainty is the result of at least two factors, the climatic variability and the uncertainty of parameter estimation; 5) a climatic process exhibits a scaling behavior, also known as long-range dependence or the Hurst phenomenon; and 6) because of this dependence, the uncertainty limits of the future are affected by the available observations of the past. The last two lines differ from classical statistical considerations and produce uncertainty limits that eventually are much wider than those of classical statistics. A combination of analytical and Monte Carlo methods is developed to determine uncertainty limits for the nontrivial scaling case. The framework developed is applied with temperature, rainfall, and runoff data from a catchment in Greece, for which data exist for about a century. The uncertainty limits are then superimposed onto deterministic projections up to 2050, obtained for several scenarios and climatic models combined with a hydrologic model. These projections indicate a significant increase of temperature in the future, beyond uncertainty bands, and no significant change of rainfall and runoff as they lie well within uncertainty limits.
Evaluation of AMIP II Global Climate Model Simulations of the Land Surface Water Budget and Its Components over the GEWEX-CEOP Regions
Authors: Irannejad P. , Henderson-Sellers A.
Published: June 2007

The land surface water balance components simulated by 20 atmospheric global circulation models (AGCMs) participating in phase II of the Atmospheric Model Intercomparison Project (AMIP II) are analyzed globally and over seven Global Energy and Water Cycle Experiment Coordinated Enhanced Observing Period basins. In contrast to the conclusions from analysis of AMIP I, the results presented here suggest that the group average of available AGCMs does not outperform all individual AGCMs in simulating the surface water balance components. Analysis shows that the available reanalysis products are not appropriate for evaluation of AGCMs’ simulated land surface water components. The worst simulation of the surface water budget is in the Murray–Darling, the most arid basin, where all the reanalyses and seven of the AGCMs produce a negative surface water budget, with evaporation alone exceeding precipitation and soil moisture decreasing over the whole AMIP II period in this basin. The spatiotemporal correlation coefficients between observed and AGCM-simulated runoff are smaller than those for precipitation. In almost all basins (except for the two most arid basins), the spatiotemporal variations of the AGCMs’ simulated evaporation are more coherent and agree better with observations, compared to those of simulated precipitation. This suggests that differences among the AGCMs’ surface water budget predictions are not solely due to model-generated precipitation differences. Specifically, it is shown that different land surface parameterization schemes partition precipitation between evaporation and runoff differently and that this, in addition to the predicted differences in atmospheric forcings, is responsible for different predictions of basin-scale water budgets. The authors conclude that the selection of a land surface scheme for an atmospheric model has significant impacts on the predicted continental and basin-scale surface hydrology.
An Analysis of the Warm-Season Diurnal Cycle over the Continental United States and Northern Mexico in General Circulation Models
Authors: Lee Myong-In , Schubert Siegfried D. , Suarez Max J. , Held Isaac M. , Lau Ngar-Cheung , Ploshay Jeffrey J. , Kumar Arun , Kim Hyun-Kyung , Schemm Jae-Kyung E.
Published: June 2007

The diurnal cycle of warm-season rainfall over the continental United States and northern Mexico is analyzed in three global atmospheric general circulation models (AGCMs) from NCEP, GFDL, and the NASA Global Modeling Assimilation Office (GMAO). The results for each model are based on an ensemble of five summer simulations forced with climatological sea surface temperatures.

Although the overall patterns of time-mean (summer) rainfall and low-level winds are reasonably well simulated, all three models exhibit substantial regional deficiencies that appear to be related to problems with the diurnal cycle. Especially prominent are the discrepancies in the diurnal cycle of precipitation over the eastern slopes of the Rocky Mountains and adjacent Great Plains, including the failure to adequately capture the observed nocturnal peak. Moreover, the observed late afternoon–early evening eastward propagation of convection from the mountains into the Great Plains is not adequately simulated, contributing to the deficiencies in the diurnal cycle in the Great Plains. In the southeast United States, the models show a general tendency to rain in the early afternoon—several hours earlier than observed. Over the North American monsoon region in the southwest United States and northern Mexico, the phase of the broad-scale diurnal convection appears to be reasonably well simulated, though the coarse resolution of the runs precludes the simulation of key regional phenomena.

All three models employ deep convection schemes that assume fundamentally the same buoyancy closure based on simplified versions of the Arakawa–Schubert scheme. Nevertheless, substantial differences between the models in the diurnal cycle of convection highlight the important differences in their implementations and interactions with the boundary layer scheme. An analysis of local diurnal variations of convective available potential energy (CAPE) shows an overall tendency for an afternoon peak—a feature well simulated by the models. The simulated diurnal cycle of rainfall is in phase with the local CAPE variation over the southeast United States and the Rocky Mountains where the local surface boundary forcing is important in regulating the diurnal cycle of convection. On the other hand, the simulated diurnal cycle of rainfall tends to be too strongly tied to CAPE over the Great Plains, where the observed precipitation and CAPE are out of phase, implying that free atmospheric large-scale forcing plays a more important role than surface heat fluxes in initiating or inhibiting convection.
Large-Scale Climatic Controls on New England River Flow
Authors: Kingston Daniel G. , McGregor Glenn R. , Hannah David M. , Lawler Damian M.
Published: June 2007

Understanding atmospheric drivers of river flow variability necessitates clear knowledge of the process chain linking climate and hydrology, yet the nature of such linkages remains poorly understood for the New England region of the northeastern United States. This research gap is addressed through a composite analysis of large-scale climatic controls on monthly high and low river flow in New England for 1958–2001, based on 40-yr ECMWF Re-Analysis (ERA-40) data. Analysis is focused on climate fields at the North Atlantic spatial scale, with particular attention given to the influence of the North Atlantic Oscillation (NAO).

High (low) river flow is shown to be characterized by greater (lower) geopotential height throughout the year, and from December to April, higher (lower) temperature. Wind speed is inversely associated with river flow in all months, with wind direction more southerly (northerly) under high (low) flow situations. Relative vorticity differences reveal more cyclonic circulation centered downwind of New England under low river flow conditions (compared to high flow) from December to April. Reversal of river flow associations with temperature and vorticity in May are linked to snowmelt dynamics. Although cursory analysis suggests a positive association between the NAO and New England river flow, closer inspection reveals this to be less straightforward. River flow is more closely linked to the East Coast trough (rather than the Icelandic low and Azores high), while air temperature anomalies resemble the NAO–sea surface temperature rather than NAO–air temperature pattern.
The 25–27 May 2005 Mount Logan Storm. Part I: Observations and Synoptic Overview
Authors: Moore G. W. K. , Holdsworth Gerald
Published: June 2007

In late May 2005, three climbers were immobilized at 5400 m on Mount Logan, Canada’s highest mountain, by the high-impact weather associated with an extratropical cyclone over the Gulf of Alaska. Rescue operations were hindered by the high winds, cold temperatures, and heavy snowfall associated with the storm. Ultimately, the climbers were rescued after the weather cleared. Just prior to the storm, two automated weather stations had been deployed on the mountain as part of a research program aimed at interpreting the climate signal contained in summit ice cores. These data provide a unique and hitherto unobtainable record of the high-elevation meteorological conditions associated with an intense extratropical cyclone. In this paper, data from these weather stations along with surface and sounding data from the nearby town of Yakutat, Alaska, satellite imagery, and the NCEP reanalysis are used to characterize the synoptic-scale conditions associated with this storm. Particular emphasis is placed on the water vapor transport associated with this storm.

The authors show that during this event, subtropical moisture was transported northward toward the Mount Logan region. The magnitude of this transport into the Gulf of Alaska was exceeded only 1% of the time during the months of May and June over the period 1948–2005. As a result, the magnitude of the precipitable water field in the Gulf of Alaska region attained values usually found in the Tropics. An atmospheric moisture budget analysis indicates that most of the moisture advected into the Mount Logan region was preexisting water vapor already in the subtropical atmosphere and was not water vapor evaporated from the surface during the evolution of the storm. Implications of this moisture source for understanding of the water isotopic climate signal in the Mount Logan ice cores will be discussed.
The Influence of Precipitation Variability and Partial Irrigation within Grid Cells on a Hydrological Simulation
Authors: Tang Qiuhong , Oki Taikan , Kanae Shinjiro , Hu Heping
Published: June 2007

The effects of natural and anthropogenic heterogeneity on a hydrological simulation are evaluated using a distributed biosphere hydrological model (DBHM) system. The DBHM embeds a biosphere model into a distributed hydrological scheme, representing both topography and vegetation in a mesoscale hydrological simulation, and the model system includes an irrigation scheme. The authors investigated the effects of two kinds of variability, precipitation variability and the variability of irrigation redistributing runoff, representing natural and anthropogenic heterogeneity, respectively, on hydrological processes. Runoff was underestimated if rainfall was placed spatially uniformly over large grid cells. Accounting for precipitation heterogeneity improved the runoff simulation. However, the negative runoff contribution, namely, the situation that mean annual precipitation is less than evapotranspiration, cannot be simulated by only considering the natural heterogeneity. This constructive model shortcoming can be eliminated by accounting for anthropogenic heterogeneity caused by irrigation water withdrawals. Irrigation leads to increased evapotranspiration and decreased runoff, and surface soil moisture in irrigated areas increases because of irrigation. Simulations performed for the Yellow River basin of China indicated streamflow decreases of 41% due to irrigation effects. The latent heat flux in the peak irrigation season [June–August (JJA)] increased 3.3 W m−2 with a decrease in the ground surface temperature of 0.1 K for the river basin. The maximum simulated increase in the latent heat flux was 43 W m−2, and the ground temperature decrease was 1.6 K in the peak irrigation season.
Impact of Vegetation Feedback on the Response of Precipitation to Antecedent Soil Moisture Anomalies over North America
Authors: Kim Yeonjoo , Wang Guiling
Published: June 2007

Previous studies support a positive soil moisture–precipitation feedback over a major fraction of North America; that is, initial soil moisture anomalies lead to precipitation anomalies of the same sign. To investigate how vegetation feedback modifies the sensitivity of precipitation to initial soil moisture conditions over North America, a series of ensemble simulations are carried out using a modified version of the coupled Community Atmosphere Model–Community Land Model (CAM–CLM). The modified CLM includes a predictive vegetation phenology scheme so that the coupled model can represent interactions between soil moisture, vegetation, and precipitation at the seasonal time scale. The focus of this study is on how the impact of vegetation feedback varies with the timing and direction of initial soil moisture anomalies. During summer, wet soil moisture anomalies lead to increase in leaf area index and, consequently, increase in evapotranspiration and surface heating. Such increases tend to favor precipitation. Therefore, under wet summer soil moisture anomalies, the soil moisture–induced precipitation increase is reinforced when predictive phenology is included. That is, the vegetation feedback to precipitation is positive. The response of vegetation to dry soil moisture anomalies in the summer months, however, is not significant due probably to a dry bias in the model, so the resulting vegetation feedback on precipitation is minimal. To soil moisture anomalies in spring, the leaf area index (LAI) response is delayed since LAI is still limited by cold temperature at that time of the year. During the summer following wet spring soil moisture anomalies, vegetation feedback is negative; that is, it tends to suppress the response of precipitation through the depletion of soil moisture by vegetation.
The Earnings of Tied-Migrant Military Husbands
Authors: Little Roger D. , Hisnanick John J.
Published: June 2007

Identifying the earnings penalty associated with being a tied mover has focused on the working wives of servicemen. However, the number of women serving in the armed forces now makes it feasible to study the earnings losses of a group of tied-mover males, the husbands of servicewomen. Using data from the 2000 U.S. Census, the authors identified a sample of such men and compare their earnings to civilian husbands of working civilian wives to extend and generalize on tied-mover earnings effects. Multivariate analysis accounting for selection bias and controlling for migration, demographic, household, and labor market characteristics shows that military husbands earn about 70 percent of civilian husbands, whereas military wives earned about 50 percent of civilian wives. Since different estimation procedures provide comparable outcomes regardless of gender, these results reveal a detrimental earnings effect for military husbands similar to earlier estimates for military wives.
The Existence of Group Cohesion in the Armed Forces
Authors: King Anthony
Published: June 2007

In July 2006, Armed Forces & Society published an article by Anthony King, “The Word of Command: Communication and Cohesion in the Military.” Guy Siebold took issue with King's model of group cohesion and his conclusions in a Disputatio Sine Fine response titled “The Essence of Military Group Cohesion,” published in the January 2007 issue. In that article, Siebold argued that social psychologists have always emphasized the centrality of collective practice to group cohesion; in contrast, King argues that, in fact, Siebold's criticism invokes an essentialist concept of cohesion. For Siebold, social cohesion refers to the underlying bond between soldiers, which exists independently of any particular activity. King, by contrast, maintains that cohesion cannot be separated from the collective practices in which military personnel are engaged and, therefore, there is a difference between the sociological position he originally developed and social—psychological approaches.
The Children's Friend Society in Upper Canada, 1833-1837
Authors: Neff Charlotte
Published: June 2007

Large scale, open immigration of unaccompanied dependent children to Canada did not commence until 1869, but it had been advocated for decades and some such immigration to the British North American colonies took place earlier in the century. The first systematic emigration of destitute British children was organized in the 1830s by the Children's Friend Society, which sent about 141 children to the Canadas from 1833 to 1836, at least 70 of whom went to Upper Canada. While the emigration scheme was short lived, it established that such children would be welcomed and that homes and work would be available for them, and it probably helped pave the way for a new wave of older juvenile immigrants in the 1850s, and for the high profile, large scale immigration of young dependent children that began in 1869 and continued for more than half a century.
Who is Afraid of the Spanish Inquisition? Endogamy and Culture Development Among Chiloe Encomenderos and Catholic Namesakes of Persecution Victims
Authors: Hojman David E.
Published: June 2007

Almost two centuries after the final demise of the Spanish Inquisition, its effects may still be present. Fear of the Inquisition may have affected endogamy patterns and other cultural attitudes of Catholic families in Chiloe Island in Southern Chile. More generally, the same fear may have eventually influenced the development of Chilean national culture. The article looks at several groups of people with Spanish surnames, from different historical periods. In particular, it explores colonial family trees, partly formed by Chiloe encomenderos and Catholic namesakes of Inquisition victims. Incidences of possibly Jewish Spanish surnames, and the different “crimes” investigated by the Inquisition tribunal in Lima, are examined. A new, short list of those most exposed to harassment and intimidation by the Inquisition in the seventeenth and eighteenth centuries is put together. In its light, the article discusses the evolution of family trees, generation after generation.
Something Old, Something New: Hungarian Marriage Patterns in Historical Perspective
Authors: Kulcsár László J.
Published: June 2007

Marriage patterns are probably the most sensitive to changes in social norms or economic structure, and closely follow the development path of a society. This study investigates the changing trends of nuptiality in Hungary from the late-nineteenth to the early-twenty-first century. With the help of Hungarian historical statistical data, changes are presented from the perspective of broader socioeconomic development over time, during which Hungary has turned from a predominantly agrarian society into a modern urban one. This study provides a historical demographic overview of a country where state intervention in the social norms and collective behavior was itself a norm for a long time.