bluuebunny/crossref_metadata_2025 huggingface dataset:
Kaposi's Sarcoma-Associated Herpesvirus-Related Solid Lymphoma Involving the Heart and Brain
Authors: Andrews Jason R. , Cho-Park Yoon Andrew , Ferry Judith , Abramson Jeremy S. , Robbins Gregory K.
Published: April 2011

Since its discovery in 1994, Kaposi's sarcoma-associated herpesvirus (KSHV) has been associated with lymphoproliferative disorders, particularly in patients infected with human immunodeficiency virus (HIV). The disorders most strongly linked to KSHV are multicentric Castleman's Disease (MCD), primary effusion lymphoma, and diffuse large B-cell lymphomas. We report an unusual case of KSHV-associated lymphoma in an HIV-infected patient manifesting with myocardial and central nervous system involvement. We discuss this case in the context of increasing array of KSHV-associated lymphomas. In the HIV-infected patient with a mass lesion, a history of cutaneous Kaposi's sarcoma and prolonged immunosuppression should alert clinicians as to the possibility of KSHV-associated lymphoproliferative disorders, in order to establish a timely diagnosis.
An Implicit Hierarchical Fixed-Point Approach to General Variational Inequalities in Hilbert Spaces
Authors: Zeng LC , Wen Ching-Feng , Yao JC
Published: April 2011

Let "Equation missing" be a nonempty closed convex subset of a real Hilbert space "Equation missing". Let "Equation missing" be a "Equation missing"-Lipschitzian and "Equation missing"-strongly monotone operator with constants "Equation missing", "Equation missing" be nonexpansive mappings with "Equation missing" where "Equation missing" denotes the fixed-point set of "Equation missing", and "Equation missing" be a "Equation missing"-contraction with coefficient "Equation missing". Let "Equation missing" and "Equation missing", where "Equation missing". For each "Equation missing", let "Equation missing" be a unique solution of the fixed-point equation "Equation missing". We derive the following conclusions on the behavior of the net "Equation missing" along the curve "Equation missing": (i) if "Equation missing", as "Equation missing", then "Equation missing" strongly, which is the unique solution of the variational inequality of finding "Equation missing" such that "Equation missing" and (ii) if "Equation missing", as "Equation missing", then "Equation missing" strongly, which is the unique solution of some hierarchical variational inequality problem.
Hollow-Core Photonic Crystal Fibers for Surface-Enhanced Raman Scattering Probes
Authors: Yang Xuan , Shi Chao , Newhouse Rebecca , Zhang Jin Z. , Gu Claire
Published: April 2011

Photonic crystal fiber (PCF) sensors based on surface-enhanced Raman scattering (SERS) have become increasingly attractive in chemical and biological detections due to the molecular specificity, high sensitivity, and flexibility. In this paper, we review the development of PCF SERS sensors with emphasis on our recent work on SERS sensors utilizing hollow-core photonic crystal fibers (HCPCFs). Specifically, we discuss and compare various HCPCF SERS sensors, including the liquid-filled HCPCF and liquid-core photonic crystal fibers (LCPCFs). We experimentally demonstrate and theoretically analyze the high sensitivity of the HCPCF SERS sensors. Various molecules including Rhodamine B, Rhodamine 6G, human insulin, and tryptophan have been tested to show the excellent performance of these fiber sensors.
Regulation of Src Family Kinases in Human Cancers
Authors: Sen Banibrata , Johnson Faye M.
Published: April 2011

The nonreceptor protein tyrosine kinase Src plays a crucial role in the signal transduction pathways involved in cell division, motility, adhesion, and survival in both normal and cancer cells. Although the Src family kinases (SFKs) are activated in various types of cancers, the exact mechanisms through which they contribute to the progression of individual tumors remain to be defined. The activation of Src in human cancers may occur through a variety of mechanisms that include domain interaction and structural remodeling in response to various activators or upstream kinases and phosphatastes. Because of Src's prominent roles in invasion and tumor progression, epithelial-to-mesenchymal transition, angiogenesis, and the development of metastasis, Src is a promising target for cancer therapy. Several small molecule inhibitors of Src are currently being investigated in clinical trials. In this article, we will summarize the mechanisms regulating Src kinase activity in normal and cancer cells and discuss the status of Src inhibitor development against various types of cancers.
Antidepressant-Resistant Depression and Antidepressant-Associated Suicidal Behaviour: The Role of Underlying Bipolarity
Authors: Rihmer Zoltan , Gonda Xenia
Published: April 2011

The complex relationship between the use of antidepressants and suicidal behaviour is one of the hottest topics of our contemporary psychiatry. Based on the literature, this paper summarizes the author's view on antidepressant-resistant depression and antidepressant-associated suicidal behaviour. Antidepressant-resistance, antidepressant-induced worsening of depression, antidepressant-associated (hypo)manic switches, mixed depressive episode, and antidepressant-associated suicidality among depressed patients are relatively most frequent in bipolar/bipolar spectrum depression and in children and adolescents. As early age at onset of major depressive episode and mixed depression are powerful clinical markers of bipolarity and the manic component of bipolar disorder (and possible its biological background) shows a declining tendency with age antidepressant-resistance/worsening, antidepressant-induced (hypo)manic switches and “suicide-inducing” potential of antidepressants seem to be related to the underlying bipolarity.
Induction of Retinoid X Receptor Activity and Consequent Upregulation of p21WAF1/CIP1 by Indenoisoquinolines in MCF7 Cells
Authors: Park Eun-Jung , Kondratyuk Tamara P. , Morrell Andrew , Kiselev Evgeny , Conda-Sheridan Martin , Cushman Mark , Ahn Soyoun , Choi Yongsoo , White Jerry J. , van Breemen Richard B. , Pezzuto John M.
Published: April 2011

Retinoid X receptor (RXR) has been targeted for the chemoprevention and treatment of cancer. To discover potential agents acting through RXRs, we utilized an RXR response element (RXRE)-luciferase reporter gene assay. Following extensive screening, 3-amino-6-(3-aminopropyl)-5,6-dihydro-5,11-dioxo-11H-indeno[1,2-c]isoquinoline dihydrochloride (AM6-36) was found to induce RXRE-luciferase activities. AM6-36 inhibited COX-2 expression and anchorage-independent growth with 12-O-tetradecanoylphorbol 13-acetate-stimulated JB6 Cl41 cells, induced the expression of CD38 in HL-60 cells, and attenuated the growth of N-methyl-N-nitrosourea–induced mammary tumors in rats. Consistent with other reports describing the antiproliferative effects of RXR agonists in breast cancers, AM6-36 showed growth inhibition with cultured MCF7 breast cancer cells, accompanied by G2/M-phase arrest at lower concentrations and enhanced S-phase arrest at higher concentrations. On the basis of DNA microarray analysis, AM6-36 upregulated the expression of CDKN1A, a target gene of RXR, by 35-fold. In accord with this response, the expression of the corresponding protein, p21WAF1/CIP1, was increased in the presence of AM6-36. Induction of p21 by AM6-36 was abrogated following transient knockdown of RXRα, demonstrating that the effect of AM6-36 on the expression of p21 is closely related to modulation of RXRα transcriptional activity. Intestinal permeability was suggested with Caco-2 cells and limited metabolism resulted when AM6-36 was incubated with human liver microsomes. Oral administration with rats resulted in 0.8 μg/mL, 4.3 μg/g, and 0.3 μg/g in serum, liver, and mammary gland, respectively. In sum, these data suggest that AM6-36 is a promising lead for the treatment or prevention of breast cancer and provide a strong rationale for testing in more advanced antitumor systems. Cancer Prev Res; 4(4); 592–607. ©2011 AACR.
Exercise for Secondary Prevention of Breast Cancer: Moving from Evidence to Changing Clinical Practice
Authors: Schmitz Kathryn H.
Published: April 2011

Relating to the report of Irwin and colleagues in this issue of the journal (beginning on page 522), this perspective discusses exercise training interventions as secondary prevention in breast cancer survivors. Burgeoning observational evidence indicates that prescribing aerobic exercise of 3 hours or more per week could have meaningful mortality and morbidity benefits for breast cancer survivors. Adherence to this exercise prescription, however, will require an infrastructure to guide survivors and to address the common clinical treatment sequelae that might interfere with survivors’ ability to regularly perform this level of activity (e.g., symptoms related to estrogen deprivation, arthralgias due to aromatase inhibitors, fatigue, lymphedema, chemotherapy-induced peripheral neuropathy, osteoporosis, upper-extremity functional impairments, and overall functional decline). On the basis of cardiac rehabilitation, a model is proposed to integrate exercise prescription into breast cancer survivor clinical care, with referral to community-based programs for most women. Cancer Prev Res; 4(4); 476–80. ©2011 AACR.
Mutations in FOXC2 in Humans (Lymphoedema Distichiasis Syndrome) Cause Lymphatic Dysfunction on Dependency
Authors: Mellor Russell H. , Tate Naomi , Stanton Anthony W.B. , Hubert Charlotte , Mäkinen Taija , Smith Alberto , Burnand Kevin G. , Jeffery Steve , Levick J. Rodney , Mortimer Peter S.
Published: April 2011

Background: Human lymphoedema distichiasis syndrome (LDS) results from germline mutations in transcription factor FOXC2. In a mouse model, lack of lymphatic and venous valves is observed plus abnormal smooth muscle cell recruitment to initial lymphatics. We investigated the mechanism of lymphoedema in humans with FOXC2 mutations, specifically the effect of gravitational forces on dermal lymphatic function. Methods: We performed (1) quantitative fluorescence microlymphangiography (FML) on the skin of the forearm (non-swollen region) at heart level, and the foot (swollen region) below heart level (dependent) and then at heart level, and (2) immunohistochemical staining of microlymphatics in forearm and foot skin biopsies, using antibodies to podoplanin, LYVE-1 and smooth muscle actin. Results: FML revealed a marked reduction in fluid uptake by initial lymphatics in the LDS foot during dependency, yet normal uptake (similar to controls) in the same foot at heart level and in LDS forearms. In control subjects, dependency did not impair initial lymphatic filling. Immunohistochemical microlymphatic density in forearm and foot did not differ between LDS and controls. Conclusions:FOXC2 mutations cause a functional failure of dermal initial lymphatics during gravitational stress (dependency), but not hypoplasia. The results reveal a pathophysiological mechanism contributing to swelling in LDS.
Identification and Characterization of Uptake Systems for Glucose and Fructose in Rhodococcus jostii RHA1
Authors: Araki Naoto , Suzuki Toru , Miyauchi Keisuke , Kasai Daisuke , Masai Eiji , Fukuda Masao
Published: April 2011

Rhodococcusjostii RHA1 takes up and utilizes glucose and fructose as its sole carbon source. To address glucose and fructose transport systems in RHA1, an in silico analysis was performed. BLAST searches revealed that the ro02365 and ro06844 genes share 51 and 47% amino acid identity, respectively, with the major facilitator superfamily (MFS) glucose transporter, GlcP, of Streptomycescoelicolor A3(2) and the ro01549–01552 and ro06781–06785 loci share 43–51% amino acid identity with proteins of the phosphotransferase system (PTS) in S. coelicolor A3(2). Real-time reverse transcription-polymerase chain reaction analysis indicated that ro02365 and ro06781 were upregulated during growth on glucose and fructose, respectively. The ro06781 gene is an ortholog of the histidine-containing phosphocarrier protein in the PTS. Deletion mutants of ro02365 and ro06781 failed to grow on glucose and fructose, respectively, indicating that these genes are essential for growth on the corresponding sugar. They also failed to take up glucose and fructose, respectively. Hence ro02365 is responsible for the uptake of glucose as a MFS transporter and was designated as glcP, and ro06781 is responsible for the uptake of fructose as a component of the PTS and was designated as ptsH.
Interest in Genetic Testing for Modest Changes in Breast Cancer Risk: Implications for SNP Testing
Authors: Graves K.D. , Peshkin B.N. , Luta G. , Tuong W. , Schwartz M.D.
Published: April 2011

Background: Advances in genomics may eventually lead to ‘personalized genetic medicine,’ yet the clinical utility of predictive testing for modest changes in risk is unclear. We explored interest in genetic testing for genes related to modest changes in breast cancer risk in women at moderate to high risk for breast cancer. Methods: Women (n = 105) with a negative breast biopsy and ≧1 relative with breast or ovarian cancer completed telephone surveys. We measured demographic and psychosocial variables and, following presentation of hypothetical scenarios of genetic tests for lower-penetrance breast cancer gene mutations, assessed interest in willingness to pay for and comprehension of test results. We used logistic regression models with generalized estimating equations to evaluate combinations of risk level, cost and behavioral modifiers. Results: Many women (77%) reported ‘definite’ interest in genetic testing, with greater interest in tests that conveyed more risk and cost less. Behavioral modifiers of risk (taking a vitamin; diet/exercise), having a regular physician, greater perceived benefits of genetic testing, and greater cancer worry also influenced interest. Most participants (63%) did not understand relative vs. absolute risk. Women with less understanding reported more cancer worry and greater willingness to pay for testing. Conclusion: Interest in genetic testing for mutations related to modest changes in risk was high, modified by both test and psychosocial factors. Findings highlight the need for education about benefits and risks of testing for mutations that convey modest changes in risk, particularly given the current lack of clinical validity/utility and availability of direct-to-consumer genetic testing.
Role of the Cytoskeleton in Formation and Maintenance of Angiogenic Sprouts
Authors: Bayless Kayla J. , Johnson Greg A.
Published: April 2011

Angiogenesis is the formation of new blood vessels from pre-existing structures, and is a key step in tissue and organ development, wound healing and pathological events. Changes in cell shape orchestrated by the cytoskeleton are integral to accomplishing the various steps of angiogenesis, and an intact cytoskeleton is also critical for maintaining newly formed structures. This review focuses on how the 3 main cytoskeletal elements – microfilaments, microtubules, and intermediate filaments – regulate the formation and maintenance of angiogenic sprouts. Multiple classes of compounds target microtubules and microfilaments, revealing much about the role of actin and tubulin and their associated molecules in angiogenic sprout formation and maintenance. In contrast, intermediate filaments are much less studied, yet intriguing evidence suggests a vital, but unresolved, role in angiogenic sprouting. This review discusses evidence for regulatory molecules and pharmacological compounds that affect actin, microtubule and intermediate filament dynamics to alter various steps of angiogenesis, including endothelial sprout formation and maintenance.
In Favor of Tipping the Balance: Animal Rights Activists in Defense of Residential Picketing
Authors: Goodman Justin R. , Sanders Clinton R.
Published: April 2011

This discussion focuses on the rationales employed by animal rights activists to explain their involvement in, and support of, protest tactics that are controversial both inside and outside the animal rights movement. The paper centers on the use of residential picketing (“home demos”) in a campaign against a private, multinational animal testing firm. Using ethnographic data and semistructured interviews with activists, the discussion demonstrates that these activists are aware of the marginality of their tactics. Despite some ambivalence, however, activists accept full responsibility for their actions and justify their behavior by utilizing supportive rationales that stress the perceived efficacy of home demos. Specifically, they appeal to the immediate and long-term psychological and direct and indirect material impacts on protest targets. These narratives are explored as constructions that are shaped and disseminated within the context of the state’s preoccupation with “ecoterrorism” and the movement’s internal debates regarding acceptable protest tactics.
“What Pushed Me over the Edge Was a Deer Hunter”: Being Vegan in North America
Authors: Hirschler Christopher A.
Published: April 2011

Thirty-two vegans were interviewed in order to examine the reasons for becoming vegan, the sustaining motivation to persist, the interpersonal and intrapersonal impact of the diet and associated practices, and the vegans’ assessment of omnivores’ eating practices. Interviews were analyzed using a model that diagrams the process of becoming vegan provided by McDonald (2000). Participants reported strained professional and personal relationships as a result of their diet and beliefs. Vegan diets were associated with an increase in physical, eudaemonic, and spiritual well-being.
Which “All” Sinned? Rom 3:23-24 Reconsidered
Authors: Johnston J. William
Published: April 2011

Because πς is a rather elastic pronominal adjective, the sense and scope of “all” must be carefully handled in context. The expression “all have sinned” in Rom 3:23 is tightly focused on “all who believe” in Rom 3:22, thus making more of Jew-Gentile relations in the early church than providing a prooftext of universal condemnation. Such a recognition also helps clarify that 3:24 is from Paul rather than traditional material. While it is undoubtedly true Paul sees the whole of humanity as condemned (cf. Rom 5:12), the scope of “all” is without distinction more than it is without exception.
The Text of P.Oxy. 4968 and Its Relationship with the Text of Codex Bezae
Authors: Gäbel Georg
Published: April 2011

This essay discusses the text of the recently published P.Oxy. 4968, which contains parts of Acts 10-12, 15-17, and its relationship with the text of Codex Bezae (D05) and some other witnesses. The text of P.Oxy. 4968 is characterized by tendencies to add and to omit, by a high number of singular variants, and by a high number of variants agreeing with variants in D05. After close scrutiny of some of the latter, a model is sketched of the development of the particular strand of textual tradition (formerly called “Western” text) to which they belong. While some variants common to P.Oxy. 4968 and D05 clearly reveal theological interests, it is suggested that others might be more aptly described in terms of narrative criticism.
Romans 16:2, προσττις/προσττης, and the Application of Reciprocal Relationships to New Testament Texts
Authors: MacGillivray Erlend D.
Published: April 2011

This article re-examines the meaning of the title προσττις given to Phoebe in Rom 16:2—commonly understood in contemporary scholarship as presenting Phoebe as Paul’s patron. This position is challenged with reference to recent studies which argue for broadening our understanding of ancient reciprocity beyond the definitions of a patron—client relationship, and also by re-evaluating the semantic range of προσττις/προσττης. It argues that we should see Phoebe and Paul’s relationship as working within a general reciprocity dynamic of benefaction, rather than within the specific relationship of the patron-client relationship.
Slavery and Emancipation in Traditional Ethiopia: The Role of the Fetha Nagast, or Laws of the Kings
Authors: Pankhurst Richard
Published: April 2011

This paper is concerned with slavery and emancipation in traditional Ethiopia and in particular with the role of the country’s legal code, the Fetha Nagast or Laws of the Kings. This document, it should be emphasised, discusses household or domestic slavery, which was widely practised in old-time Christian Ethiopia, and resulted largely from the capture of men, women and children in warfare. Such slavery, which differed in many ways from the capitalistic slavery of later time and climes, was accepted by the Fetha Nagast, which justified it by Biblical Writ. The code nevertheless gave its blessing to the principle of slave emancipation, which it described as the Highest form of Charity ‐ and specified when it was the slave owner’s duty wherever possible to emancipate his or her slaves.
African Settlers on the West Coast of India: The Sidi Elite of Janjira
Authors: Jasdanwalla Faaeza
Published: April 2011

This paper discusses the political history of the Indian princely state of Janjira on the west coast of India. It was ruled by Sidis (Africans) from the early seventeenth century until the merger of princely states immediately after the independence of India in 1947. The Sidi rulers of Janjira were of African origin, having initially entered India as traders and serving in administrative capacities with the medieval Deccan kingdoms. The emphasis of this paper will be on the manner in which the rulers of Janjira were elected by a group of African Sidi chiefs or Sardars from amongst them for almost two centuries, as opposed to relying on hereditary primogeniture as a system of succession, and the implications that such a system had on the history of Janjira.
News & Views As Easy as A, B and C: Will A, B and C v. Ireland Be Ireland’s Wake-up Call for Abortion Rights?
Authors: Staunton Ciara
Published: April 2011

This article examines the development of Ireland’s abortion policy from 1861 to the present day. It explores the reasoning for this policy as well as the inherent problems with this policy. It examines in detail the A, B and C v. Ireland judgement and its impact, (if any) on Irish abortion law. Finally, it discusses the margin of appreciation doctrine used by the European Court of Human Rights in deciding cases of a moral nature.
A Matter of Health? Legal Aspects of Private Umbilical Cord Blood Banking
Authors: Vidalis Takis
Published: April 2011

Private umbilical cord blood banking raises a question of special legal regulation. This practice promises the safe storage of biological material on the assumption that it may be useful, at a certain moment in future, for its own donor (or for a donor’s close family member) for curing serious blood diseases. Although currently the therapeutic value of umbilical cord blood is confirmed, there are strong scientific doubts and relevant controversies regarding its use in autologous transplantations. This fact produces conditions of legal uncertainty, since the benefit for those wanting to conclude contracts with private umbilical cord blood banks is not clear. The Greek example illustrates this situation of regulatory deficit well, which eventually creates a major problem, given the increasing number of private banks offering relevant services in the country.
Transitional Justice, Truth and Reconciliation: An Under-Explored Relationship
Authors: Clark Janine Natalya
Published: April 2011

Much of the literature on transitional justice suffers from a critical impact gap, which scholars are only now beginning to address. One particular manifestation of this aforementioned gap, and one which forms the particular focus of this article, is the frequently-cited yet empirically under-researched claim that "truth" fosters post-conflict reconciliation. Theoretically and empirically critiquing this argument, this article both questions the comprehensiveness of truth established through criminal trials and truth and reconciliation commissions (TRCs) and underscores the often overlooked problem of denial, thus raising fundamental questions about the reputed healing properties of truth in such contexts. Advocating the case for evidence-based transitional justice, it reflects upon empirical research on South Africa's TRC and the author's own work on the International Criminal Tribunal for the former Yugoslavia (ICTY).
The Role of the Victim in the Criminal Process – A Paradigm Shift in National German and International Law?
Authors: Safferling Christoph
Published: April 2011

The respect for the situation of victims of crime has risen immensely over the last couple of decades. Consequently the importance of the victim at trial has changed radically. First, the victim deserves protection from secondary victimisation in the course of prosecution; secondly, the victim is attributed a more active role compared to the mere role as a witness for the prosecution. The traditional idea of a "public" prosecution, whereby the prosecutor as a state official mediates the victim, is considerably challenged if the victim acts as a "private" prosecutor. The article analyses recent developments both in German and international criminal procedural law concerning "victim participation" and contrasts this development with the interests and expectations voiced by victims of crime. It is held that criminal procedure should not be overburdened with unrealistic expectations as contributing to an overall healing process and stay focused on its main aim: determining the guilt of the alleged offender.
The Evolution of International Criminal Law: Prosecuting 'New' Crimes before the Special Court for Sierra Leone
Authors: Wharton Sara
Published: April 2011

The Special Court for Sierra Leone has been noted for becoming the first international court to convict accused of the crimes of sexual slavery, the use of child soldiers, 'forced marriage', and intentionally directing attacks against peacekeepers. This article analyzes how prosecutions of some of these supposedly 'new' crimes were found not to be in violation of the principle of legality, nullum crimen sine lege. In particular, this article will focus on the crimes of 'forced marriage', intentionally directing attacks against peacekeepers, and sexual slavery: the judgments in the RUF case (Prosecutor v. Sesay, Kallon and Gbao) and the AFRC case (Prosecutor v. Brima, Kamara and Kanu) together reveal two different processes through which the law has proven able to evolve and adapt to accommodate so-called 'new' crimes without violating the principle of legality.
The Therapeutic Dimension of Transitional Justice: Emotional Repair and Victim Satisfaction in International Trials and Truth Commissions
Authors: Doak Jonathan
Published: April 2011

This article examines the capacity of two major transitional justice mechanisms, international criminal trials and truth commissions, to provide a measure of emotional repair to the victims of some of humanity's most serious criminal acts. It is suggested that transitional justice processes often afford inadequate attention to the needs and rights of individual victims; but that four antecedents – account-making; truth-finding; justice and deliberative encounter may make some contribution to unlocking the therapeutic potential of these processes. While trials and truth commissions may both continue to play key roles in transitional settings, such processes should be conceived as individual elements of a more complex package of measures that should be put in place to propel peacemaking and healing at both individual and societal levels.
A Comparison of MERRA and NARR Reanalyses with the DOE ARM SGP Data
Authors: Kennedy Aaron D. , Dong Xiquan , Xi Baike , Xie Shaocheng , Zhang Yunyan , Chen Junye
Published: April 2011

Atmospheric states from the Modern-Era Retrospective analysis for Research and Applications (MERRA) and the North American Regional Reanalysis (NARR) are compared with data from the Atmospheric Radiation Measurement Program (ARM) Southern Great Plains (SGP) site, including the ARM continuous forcing product and Cloud Modeling Best Estimate (CMBE) soundings, during the period 1999–2001 to understand their validity for single-column model (SCM) and cloud-resolving model (CRM) forcing datasets. Cloud fraction, precipitation, and radiation information are also compared to determine what errors exist within these reanalyses. For the atmospheric state, ARM continuous forcing and the reanalyses have good agreement with the CMBE sounding information, with biases generally within 0.5 K for temperature, 0.5 m s−1 for wind, and 5% for relative humidity. Larger disagreements occur in the upper troposphere (p < 300 hPa) for temperature, humidity, and zonal wind, and in the boundary layer (p > 800 hPa) for meridional wind and humidity. In these regions, larger errors may exist in derived forcing products. Significant differences exist for vertical pressure velocity, with the largest biases occurring during the spring upwelling and summer downwelling periods. Although NARR and MERRA share many resemblances to each other, ARM outperforms these reanalyses in terms of correlation with cloud fraction. Because the ARM forcing is constrained by observed precipitation that gives the adequate mass, heat, and moisture budgets, much of the precipitation (specifically during the late spring/early summer) is caused by smaller-scale forcing that is not captured by the reanalyses. While reanalysis-based forcing appears to be feasible for the majority of the year at this location, it may have limited usage during the late spring and early summer, when convection is common at the ARM SGP site. Both NARR and MERRA capture the seasonal variation of cloud fractions (CFs) observed by ARM radar–lidar and Geostationary Operational Environmental Satellite (GOES) with high correlations (0.92–0.78) but with negative biases of 14% and 3%, respectively. Compared to the ARM observations, MERRA shows better agreement for both shortwave (SW) and longwave (LW) fluxes except for LW-down (due to a negative bias in water vapor): NARR has significant positive bias for SW-down and negative bias for LW-down under clear-sky and all-sky conditions. The NARR biases result from a combination of too few clouds and a lack of sufficient extinction by aerosols and water vapor in the atmospheric column. The results presented here represent only one location for a limited period, and more comparisons at different locations and longer periods are needed.
On the Possible Link between Tropical Convection and the Northern Hemisphere Arctic Surface Air Temperature Change between 1958 and 2001
Authors: Lee Sukyoung , Gong Tingting , Johnson Nathaniel , Feldstein Steven B. , Pollard David
Published: April 2011

This study presents mechanisms for the polar amplification of surface air temperature that occurred in the Northern Hemisphere (NH) between the periods of 1958–77 (P1) and 1982–2001 (P2). Using European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-40) reanalysis data, it is found that over the ice-covered Arctic Ocean, the winter surface warming arises from dynamic warming (stationary eddy heat flux and adiabatic warming). Over the ice-free Arctic Ocean between the Greenland and the Barents Seas, downward infrared radiative (IR) flux is found to dominate the warming.

To investigate whether the difference in the flow between P1 and P2 is due to changes in the frequency of occurrence of a small number of teleconnection patterns, a coupled self-organizing map (SOM) analysis of the 250-hPa streamfunction and tropical convective precipitation is performed. The latter field was specified to lead the former by 5 days. The results of the analysis showed that the P2 − P1 trend arises from a decrease in the frequency of negative phase PNA-like and circumglobal streamfunction patterns and a corresponding increase in the frequency of positive PNA-like and circumglobal streamfunction patterns. The occurrence of the two strong 1982–83 and 1997–98 El Niño events also contributes toward this trend. The corresponding trend in the convective precipitation is from below average to above average values in the tropical Indo-western Pacific region. Each of the above patterns was found to have an e-folding time scale from 6 to 8 days, which implies that the P2 − P1 trend can be understood as arising from the change in the frequency of occurrence of teleconnection patterns that fluctuate on intraseasonal time scales.

The link between intraseasonal and interannual variability was further examined by linearly regressing various quantities against trend patterns with interannual variability subtracted. It was found that enhanced convective precipitation is followed 3–6 days later by the occurrence of the P2 − P1 circulation trend pattern, and then 1–2 days later by the corresponding trend pattern in the downward IR flux. This finding suggests that an increased frequency of the above sequence of events, which occurs on intraseasonal time scales, can account for the NH winter polar amplification of the surface air temperature via increased dynamic warming and downward IR flux.
Principal Component Analysis of Observed and Modeled Diurnal Rainfall in the Maritime Continent
Authors: Teo Chee-Kiat , Koh Tieh-Yong , Chun-Fung Lo Jeff , Chandra Bhatt Bhuwan
Published: April 2011

Principal component analysis (PCA) is able to diagnose the diurnal rain cycle in the Maritime Continent into two modes that explain most of the diurnal variability in the region. The first mode results from the differential variation in potential instability forced by surface heat flux, insolation, and longwave radiative cooling on land and sea. The second mode is associated with intrinsic mesoscale dynamics of convective systems and its interactions with gravity waves, density currents, and local circulations in coastal regions or mountainous terrain. The spatial phase relation between the two modes determines whether a diurnal signal is propagating or stationary. Thus, validating model simulations of diurnal rainfall using PCA provides insights on the representation of dynamics and physics. In this paper, the main modes of diurnal rain variability in the Maritime Continent from satellite observations are studied and are compared with those from Weather Research and Forecasting (WRF) model simulations. Hovmoeller analyses of the reconstructed rainfall from the first two PCA modes clarify the impact of coastlines and mountains as sources of propagating signals. Wave cavities are identified in the Straits of Malacca, Malay Peninsula, and north Sumatra where stationary signals are produced. WRF reproduces the first two modes but each with a phase lead of about 1–2 h or longer, depending on the satellite rainfall product used for comparison. The basic diurnal forcing in the model seems to be too strong and the model responds too strongly to small islands and small-scale topography. The phase speed of propagating signals over open sea is correctly modeled but that over land is too slow.
A Comparison of Extratropical Cyclones in Recent Reanalyses ERA-Interim, NASA MERRA, NCEP CFSR, and JRA-25
Authors: Hodges K. I. , Lee R. W. , Bengtsson L.
Published: April 2011

Extratropical cyclones are identified and compared using data from four recent reanalyses for the winter periods in both hemispheres. Results show the largest differences occur between the older lower resolution 25-yr Japanese Reanalysis (JRA-25) when compared with the newer high resolution reanalyses, particularly in the Southern Hemisphere (SH). Spatial differences between the newest reanalyses are small in both hemispheres and generally not significant except in some common regions associated with cyclogenesis close to orography. Differences in the cyclone maximum intensitites are generally related to spatial resolution except in the NASA Modern Era Retrospective-Analysis for Research and Applications (NASA MERRA), which has larger intensities for several different measures. Matching storms between reanalyses shows the number matched between the ECMWF Interim Re-Analysis (ERA-Interim) and the other reanalyses is similar in the Northern Hemisphere (NH). In the SH the number matched between JRA-25 and ERA-Interim is lower than in the NH; however, for NASA MERRA and the NCEP Climate Forecast System Reanalysis (NCEP CFSR), the number matched is similar to the NH. The mean separation of the identically same cyclones is typically less than 2° geodesic in both hemispheres for the latest reanalyses, whereas JRA-25 compared with the other reanalyses has a broader distribution in the SH, indicating greater uncertainty. The instantaneous intensity differences for matched storms shows narrow distributions for pressure, while for winds and vorticity the distributions are much broader, indicating larger uncertainty typical of smaller-scale fields. Composite cyclone diagnostics show that cyclones are very similar between the reanalyses, with differences being related to the intensities, consistent with the intensity results. Overall, results show NH cyclones correspond well between reanalyses, with a significant improvement in the SH for the latest reanalyses, indicating a convergence between reanalyses for cyclone properties.
Observed Decadal Changes in Downward Wave Coupling between the Stratosphere and Troposphere in the Southern Hemisphere
Authors: Harnik Nili , Perlwitz Judith , Shaw Tiffany A.
Published: April 2011

Downward wave coupling dominates the intraseasonal dynamical coupling between the stratosphere and troposphere in the Southern Hemisphere. The coupling occurs during late winter and spring when the stratospheric basic state forms a well-defined meridional waveguide, which is bounded above by a reflecting surface. This basic-state configuration is favorable for planetary wave reflection and guides the reflected waves back down to the troposphere, where they impact wave structures. In this study decadal changes in downward wave coupling are analyzed using the Modern Era Retrospective-Analysis for Research and Applications (MERRA) dataset.

A cross-spectral correlation analysis, applied to geopotential height fields, and a wave geometry diagnostic, applied to zonal-mean zonal wind and temperature data, are used to understand decadal changes in planetary wave propagation. It is found that downward wave 1 coupling from September to December has increased over the last three decades, owing to significant increases at the beginning and end of this 4-month period. The increased downward wave coupling is caused by both an earlier onset of the vertically bounded meridional waveguide configuration and a persistence of this configuration into December. The latter is associated with the observed delay in vortex breakup. The results point to an additional dynamical mechanism whereby the stratosphere has influenced the tropospheric climate in the Southern Hemisphere.
How Does Shifting Pacific Ocean Warming Modulate on Tropical Cyclone Frequency over the South China Sea?
Authors: Chen Guanghua
Published: April 2011

The different modulation of El Niño Modoki and canonical El Niño events on tropical cyclone (TC) frequency over the South China Sea (SCS) during boreal summer and fall for 1960–2009 is investigated. The bootstrap resampling method and two-sample permutation procedure are applied to simulate sampling distributions and conduct statistical tests, respectively. Results from the hypothesis testing indicate that the above-normal TC frequency over the SCS occurs during June–August (JJA) for the El Niño Modoki years, whereas the below-normal TC frequency is significant during September–November (SON) for the canonical El Niño years. The remarkably opposite modulations can be attributed to the different large-scale circulation anomalies, which are consistent with Matsuno–Gill-type responses to the tropical heating source/sink over the western North Pacific (WNP) and Maritime Continent for two kinds of Pacific Ocean warming events. In response to a broad-scale convection anomaly over the WNP during JJA for El Niño Modoki, a zonally elongated cyclonic anomaly dominates the WNP and SCS, leading to enhanced TC activity. In contrast, during SON for the canonical El Niño, a markedly strengthened cooling source centered in the Maritime Continent induces an anticyclonic anomaly over the SCS, resulting in suppressed TC activity.
Reply
Authors: Penny S. M. , Roe G. H. , Battisti D. S.
Published: April 2011

Penny et al. recently showed that the midwinter suppression in storminess over the western and central Pacific Ocean is due to a reduction in the number and amplitude of “seed” disturbances entering the Pacific storm track from midlatitude Asia. In this reply, the authors strengthen the conclusions that were originally put forth and show that the apparent departure from this behavior presented in a recent comment originates in the commenters having undersampled the full dataset of interannual variability. It is shown that when the Pacific storm track is only weakly “seeded” by an upstream source, as is common during winter and uncommon during fall and spring, it is likely to be weaker than average, and this reduction is highly statistically significant and the amplitude compares well with the midwinter suppression.
Observed Interaction between Pacific Sea Ice and the Western Pacific Pattern on Intraseasonal Time Scales
Authors: Matthewman N. Joss , Magnusdottir Gudrun
Published: April 2011

The relationship between North Pacific sea ice and the Western Pacific (WP) pattern is examined using wintertime observational data between 1978 and 2008. Weekly averaged data are chosen to capture the characteristically short time scale of the WP. A clear relationship is found between the WP and sea ice concentrations in the Bering Sea, where the positive polarity of the WP is accompanied by increasing sea ice concentrations and the negative WP by decreasing sea ice concentrations. Sea ice concentrations in the Sea of Okhotsk, however, are shown to be largely insensitive to the strength of the WP. Feedback of Bering Sea sea ice concentrations onto the WP is tested by fitting weekly averaged observations to a vector autoregressive (VAR) model. Results from the VAR model indicate that feedback of Bering Sea sea ice onto the WP plays a significant role in the dynamics of the WP and that this feedback is positive; that is, WP-induced changes in Bering Sea sea ice concentrations help sustain existing WP conditions, thereby lengthening the time scale of variability of the WP.
The Skill of Seasonal Ensemble Prediction Systems to Forecast Wintertime Windstorm Frequency over the North Atlantic and Europe
Authors: Renggli Dominik , Leckebusch Gregor C. , Ulbrich Uwe , Gleixner Stephanie N. , Faust Eberhard
Published: April 2011

The science of seasonal predictions has advanced considerably in the last decade. Today, operational predictions are generated by several institutions, especially for variables such as (sea) surface temperatures and precipitation. In contrast, few studies have been conducted on the seasonal predictability of extreme meteorological events such as European windstorms in winter. In this study, the predictive skill of extratropical wintertime windstorms in the North Atlantic/European region is explored in sets of seasonal hindcast ensembles from the Development of a European Multimodel Ensemble System for Seasonal-to-Interannual Prediction (DEMETER) and the ENSEMBLE-based predictions of climate changes and their impacts (ENSEMBLES) projects.

The observed temporal and spatial climatological distributions of these windstorms are reasonably well reproduced in the hindcast data. Using hindcasts starting on 1 November, significant predictive skill is found for the December–February windstorm frequency in the period 1980–2001, but also for the January–April storm frequency. Specifically, the model suite run at Météo France shows consistently high skill.

Some aspects of the variability of skill are discussed. Predictive skill in the 1980–2001 period is usually higher than for the 1960–2001 period. Furthermore, the level of skill turns out to be related to the storm frequency of a given winter. Generally, winters with high storm frequency are better predicted than winters with medium storm frequency. Physical mechanisms potentially leading to such a variability of skill are discussed.
Ensemble State Estimation for Nonlinear Systems Using Polynomial Expansions in the Innovation
Authors: Hodyss Daniel
Published: April 2011

A new framework is presented for understanding how a nonnormal probability density function (pdf) may affect a state estimate and how one might usefully exploit the nonnormal properties of the pdf when constructing a state estimate. A Bayesian framework is constructed that naturally leads to an expansion of the expected forecast error in a polynomial series consisting of powers of the innovation vector. This polynomial expansion in the innovation reveals a new view of the geometric nature of the state estimation problem. It is shown that this expansion in powers of the innovation provides a direct relationship between a nonnormal pdf describing the likely distribution of states and a normal pdf determined by powers of the forecast error. One implication of this perspective is that when state estimation is performed on a nonnormal pdf it leads to state estimates based on the mean to be nonlinear functions of the innovation. A direct relationship is shown between the degree to which the state estimate varies with the innovation and the moments of the distribution. These and other implications of this new view of ensemble state estimation in nonlinear systems are illustrated in simple scalar systems as well as on the Lorenz attractor.
Hurricane Gustav (2008) Waves and Storm Surge: Hindcast, Synoptic Analysis, and Validation in Southern Louisiana
Authors: Dietrich J. C. , Westerink J. J. , Kennedy A. B. , Smith J. M. , Jensen R. E. , Zijlema M. , Holthuijsen L. H. , Dawson C. , Luettich R. A. , Powell M. D. , Cardone V. J. , Cox A. T. , Stone G. W. , Pourtaheri H. , Hope M. E. , Tanaka S. , Westerink L. G. , Westerink H. J. , Cobell Z.
Published: April 2011

Hurricane Gustav (2008) made landfall in southern Louisiana on 1 September 2008 with its eye never closer than 75 km to New Orleans, but its waves and storm surge threatened to flood the city. Easterly tropical-storm-strength winds impacted the region east of the Mississippi River for 12–15 h, allowing for early surge to develop up to 3.5 m there and enter the river and the city’s navigation canals. During landfall, winds shifted from easterly to southerly, resulting in late surge development and propagation over more than 70 km of marshes on the river’s west bank, over more than 40 km of Caernarvon marsh on the east bank, and into Lake Pontchartrain to the north. Wind waves with estimated significant heights of 15 m developed in the deep Gulf of Mexico but were reduced in size once they reached the continental shelf. The barrier islands further dissipated the waves, and locally generated seas existed behind these effective breaking zones.

The hardening and innovative deployment of gauges since Hurricane Katrina (2005) resulted in a wealth of measured data for Gustav. A total of 39 wind wave time histories, 362 water level time histories, and 82 high water marks were available to describe the event. Computational models—including a structured-mesh deepwater wave model (WAM) and a nearshore steady-state wave (STWAVE) model, as well as an unstructured-mesh “simulating waves nearshore” (SWAN) wave model and an advanced circulation (ADCIRC) model—resolve the region with unprecedented levels of detail, with an unstructured mesh spacing of 100–200 m in the wave-breaking zones and 20–50 m in the small-scale channels. Data-assimilated winds were applied using NOAA’s Hurricane Research Division Wind Analysis System (H*Wind) and Interactive Objective Kinematic Analysis (IOKA) procedures. Wave and surge computations from these models are validated comprehensively at the measurement locations ranging from the deep Gulf of Mexico and along the coast to the rivers and floodplains of southern Louisiana and are described and quantified within the context of the evolution of the storm.