bluuebunny/crossref_metadata_2025 huggingface dataset:
VERTEBRAL OSTEOLOGY AND COMPLEXITY INLAGENORHYNCHUS ACUTUS(DELPHINIDAE) WITH COMPARISON TO OTHER DELPHINOID GENERA
Authors: Buchholtz Emily A. , Wolkovich Elizabeth M. , Cleary Richard J.
Published: August 2006

Abstract

The vertebral column of the Atlantic white‐sided dolphin,Lagenorhynchus acutus, reflects the radical reorganization of the cetacean column for locomotion in water. Both posterior thoracic and anterior caudal vertebrae have been “lumbarized,” and discontinuities occur within the caudal series at the synclinal point and fluke base. Morphology changes subtly as body size increases. Neural process height increases more rapidly, and centrum length more variably, than other vertebral parameters. As a result, large animals have disproportionately tall neural processes, short necks, long mid‐body regions, and short flukes. Vertebral columns of large animals also show greater complexity (range, irregularity, and polarization) of centrum length than do those of smaller animals. Comparisons among dolphins reveal that complexity trends with respect to differentiation of parts run counter to the trend with respect to number of parts, a relationship predicted by Williston in 1914.
ESTIMATES OF SPERM WHALE ABUNDANCE IN THE NORTHEASTERN TEMPERATE PACIFIC FROM A COMBINED ACOUSTIC AND VISUAL SURVEY
Authors: Barlow Jay , Taylor Barbara L.
Published: August 2006

Abstract

We estimate the abundance of sperm whales in a 7.8 million km2 study area in the eastern temperate North Pacific using data from a ship‐based acoustic and visual line‐transect survey in spring 1997. Sperm whales were detected acoustically using a hydrophone array towed at 15 km/h and 100 m depth. The hydrophone array was towed for 14,500 km, and locations were estimated acoustically for 45 distinct sperm whale groups. Whales producing slow clicks (>2‐s period) were detected at greater distance (up to 37 km), and the estimation of effective strip widths was stratified based on initial click period. Visual survey effort (using 25° binoculars and naked eyes) covered 8,100 km in Beaufort sea states 0–5 and resulted in only eight sightings. The effective strip width for visual detections was estimated from previous surveys conducted using the same methods and similar vessels in the eastern Pacific. Estimated sperm whale abundance in the study area was not significantly different between acoustic (32,100, CV = 0.36) and visual (26,300, CV = 0.81) detection methods. Acoustic techniques substantially increased the number of sperm whales detected on this line‐transect survey by increasing the range of detection and allowing nighttime surveys; however, visual observations were necessary for estimating group size.
THE GUNSHOT SOUND PRODUCED BY MALE NORTH ATLANTIC RIGHT WHALES (EUBALAENA GLACIALIS) AND ITS POTENTIAL FUNCTION IN REPRODUCTIVE ADVERTISEMENT
Authors: Parks Susan E. , Hamilton Philip K. , Kraus Scott D. , Tyack Peter L.
Published: August 2006

Abstract

North Atlantic right whales (Eubalaena glacialis) make a short, distinctive broadband sound that is produced internally called a Gunshot sound. This sound has been recorded in the Bay of Fundy, Canada from both single whales (n= 9) and social surface active groups (n=49). Those single whales producing Gunshot sounds whose sex could be determined (n= 9) were all mature males. Gunshot sounds were produced as part of a stereotyped behavioral sequence by these individuals, including frequent head‐lifts and flipper slapping at the surface. In surface active groups, Gunshot sounds were commonly recorded when males were present in the group. The rate of production of Gunshot sounds was weakly correlated with the total number of males present in the group. Given the behavioral context of Gunshot sound production, and production of the sound only by male whales, Gunshots may function in a reproductive context as an advertisement signal to attract females, an agonistic signal directed toward other males, or a combination of the two functions.
A CRITICAL REVIEW OF THE REGIME SHIFT‐“JUNK FOOD”‐NUTRITIONAL STRESS HYPOTHESIS FOR THE DECLINE OF THE WESTERN STOCK OF STELLER SEA LION
Authors: Fritz Lowell W. , Hinckley Sarah
Published: August 2006

Abstract

Steller sea lions (Eumetopias jubatus) in the central and western Gulf of Alaska, Aleutian Islands, and Bering Sea have declined by 80% in the last 30 yr. One hypothesis for the decline in this western Steller sea lion population is that a climate regime shift in 1976–1977 changed the species composition of the fish community and reduced the nutritional quality (energy density) of the sea lion prey field. This in turn led to nutritional stress and reduced individual fitness, survival, and reproduction of sea lions. Implications of this regime shift‐“junk food” hypothesis are that (1) the recruitment and abundance of supposed high quality species (e.g., Pacific herring, Clupea pallasi) decreased while those of supposed low quality (e.g., species in the family Gadidae) increased following the regime shift, (2) Steller sea lion diets shifted in response to this change in fish community structure, and (3) a diet composed principally of gadids (e.g., walleye pollock, Theragra chalcogramma) is detrimental to sea lion fitness and survival. We examine data relating to each of these implications and find little support for the hypothesis that increases in the availability and consumption of gadids following the regime shift are primarily responsible for the decline of the western population of Steller sea lion.
DUGONG (DUGONG DUGON) ABUNDANCE ALONG THE ANDAMAN COAST OF THAILAND
Authors: Hines Ellen M. , Adulyanukosol Kanjana , Duffus David A.
Published: August 2006

Abstract

In 2000 and 2001, dugong abundance was estimated using aerial surveys in three provinces along the Andaman coast of Thailand. A microlite aircraft was used to fly aerial transects over seagrass areas. All surveys were done during rising tides as the dugongs came to the seagrass beds to feed. The largest population was found in Trang province. In Trang, the total number of sightings during 22 surveys was 264, out of which 31.5% were single dugongs. The largest group seen in 2000 was 30, and in 2001, 53. The maximum number of calves seen in one day was 13. The best minimum estimate of population abundance is 123 animals (CV = 60.8%) in Trang province. Higher numbers of dugong sightings and group sizes corresponded with higher tides until water turbidity impeded sightings after the highest spring tide. In other areas the number of animals seen was too small for population estimates.
Current research priorities in chronic fatigue syndrome/myalgic encephalomyelitis: disease mechanisms, a diagnostic test and specific treatments
Authors: Kerr J R , Christian P , Hodgetts A , Langford P R , Devanur L D , Petty R , Burke B , Sinclair L I , Richards S C M , Montgomery J , McDermott C R , Harrison T J , Kellam P , Nutt D J , Holgate S T
Published: August 2006

Chronic fatigue syndrome (CFS) is an illness characterised by disabling fatigue of at least 6 months duration, which is accompanied by various rheumatological, infectious and neuropsychiatric symptoms. A collaborative study group has been formed to deal with the current areas for development in CFS research—namely, to develop an understanding of the molecular pathogenesis of CFS, to develop a diagnostic test and to develop specific and curative treatments. Various groups have studied the gene expression in peripheral blood of patients with CFS, and from those studies that have been confirmed using polymerase chain reaction (PCR), clearly, the most predominant functional theme is that of immunity and defence. However, we do not yet know the precise gene signature and metabolic pathways involved. Currently, this is being dealt with using a microarray representing 47 000 human genes and variants, massive parallel signature sequencing and real-time PCR. It will be important to ensure that once a gene signature has been identified, it is specific to CFS and does not occur in other diseases and infections. A diagnostic test is being developed using surface-enhanced, laser-desorption and ionisation-time-of-flight mass spectrometry based on a pilot study in which putative biomarkers were identified. Finally, clinical trials are being planned; novel treatments that we believe are important to trial in patients with CFS are interferon-β and one of the anti-tumour necrosis factor-α drugs.
A new look at chronic fatigue syndrome/myalgic encephalomyelitis
Authors: Gibson I
Published: August 2006

It has been 3 years since the Chief Medical Officer reported on chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) and the time has come for a thorough investigation by an All Party Group drawn from the House of Commons and the House of Lords. We have received many written submissions and are engaged in taking oral evidence in 2-h sessions, which we open to the public as well as interested groups. The group has received a fantastic response to its requests for written evidence over the past few months. Questions that arise for a government response are the lack of provision and support for patients with CFS/ME, the issue of the clinical definition of CFS/ME, the need for a diagnostic test for CFS/ME, effectiveness of the National Institute for Clinical Excellence guidelines, and criteria used to decide which treatments are best for patients with CFS or myalgic encephalomyelitis.
GAGA protein: a multi-faceted transcription factorThis paper is one of a selection of papers published in this Special Issue, entitled 27th International West Coast Chromatin and Chromosome Conference, and has undergone the Journal's usual peer review process.
Authors: Adkins Nicholas L. , Hagerman Thomas A. , Georgel Philippe
Published: August 2006

The transition from transcription activation to repression is regulated at multiple levels by the DNA sequence and DNA modification to its compaction through chromatin packaging. The GAGA factor (GAF) is one of a few transcription factors that can regulate gene expression at multiple levels. It displays both activator/antirepressor and repressor activity, depending on its target genomic location. The GAF-mediated modulation of expression appears to be intimately linked with modifications of the chromatin structure. The GAF can associate with highly compacted heterochromatin, contributing to gene repression, or participate in nucleosome remodeling to activate specific genes. In this review, we are attempting to elucidate the contribution(s) of the various domains of the GAF to the recruitment of its functional partners, leading to seemingly opposite functions. We surveyed the current scientific literature for evidence of GAF involvement in regulatory events associated with changes of chromatin composition or conformation.
From transcription to transport: emerging roles for nuclear myosin IThis paper is one of a selection of papers published in this Special Issue, entitled 27th International West Coast Chromatin and Chromosome Conference, and has undergone the Journal's usual peer review process.
Authors: Hofmann Wilma A. , Johnson Terezina , Klapczynski Marcin , Fan Ji-Lao , de Lanerolle Primal
Published: August 2006

Myosins are a superfamily of actin-activated ATPases that, in the cytoplasm, work together with actin as molecular motors. The presence of actin in the nucleus has been known for many years. The demonstration of a nuclear isoform of a myosin, nuclear myosin I (NMI), stimulated a great deal of interest in possible intranuclear motor functions of an acto–NMI complex. NMI has been shown to be involved in transcription by RNA polymerases I and II. In both cases, NMI interacts with the respective polymerase and is critically involved in the basic process of transcription. A recent study on intranuclear long-range chromosome movement has now demonstrated a role for NMI in the translocation of chromosome regions as well. Moreover, this movement is based on an active and directed process that is facilitated by an acto–NMI complex, establishing for the first time a functional role for a motor complex consisting of actin and a myosin in the nucleus.
Transcriptional repression by Tup1–Ssn6This paper is one of a selection of papers published in this Special Issue, entitled 27th International West Coast Chromatin and Chromosome Conference, and has undergone the Journal's usual peer review process.
Authors: Malavé Tania M. , Dent Sharon Y.R.
Published: August 2006

The Tup1–Ssn6 complex from budding yeast is one of the best studied corepressors and has served as a model for the study of similar corepressor complexes in higher eukaryotes. Tup1–Ssn6 represses multiple subsets of genes when recruited to promoters by sequence-specific DNA binding repressors. Tup1–Ssn6 mediated repression involves interactions among the corepressor and hypoacetylated histones, histone deacetylases, and the RNA transcriptional machinery. Nucleosome positioning is also involved in repression of a subset of Tup1–Ssn6 regulated genes. These findings highlight the importance of chromatin modification states in Tup1–Ssn6 mediated repression. Here we review the multiple mechanisms involved in repression and discuss Tup1–Ssn6 homolog functions in higher organisms. We also present a model for how repression by Tup1–Ssn6 may be established.
How to build a centromere: from centromeric and pericentromeric chromatin to kinetochore assemblyThis paper is one of a selection of papers published in this Special Issue, entitled 27th International West Coast Chromatin and Chromosome Conference, and has undergone the Journal's usual peer review process.
Authors: Vos Larissa J. , Famulski Jakub K. , Chan Gordon K.T.
Published: August 2006

The assembly of the centromere, a specialized region of DNA along with a constitutive protein complex which resides at the primary constriction and is the site of kinetochore formation, has been puzzling biologists for many years. Recent advances in the fields of chromatin, microscopy, and proteomics have shed a new light on this complex and essential process. Here we review recently discovered mechanisms and proteins involved in determining mammalian centromere location and assembly. The centromeric core protein CENP-A, a histone H3 variant, is hypothesized to designate centromere localization by incorporation into centromere-specific nucleosomes and is essential for the formation of a functional kinetochore. It has been found that centromere localization of centromere protein A (CENP-A), and therefore centromere determination, requires proteins involved in histone deacetylation, as well as base excision DNA repair pathways and proteolysis. In addition to the incorporation of CENP-A at the centromere, the formation of heterochromatin through histone methylation and RNA interference is also crucial for centromere formation. The assembly of the centromere and kinetochore is complex and interdependent, involving epigenetics and hierarchical protein–protein interactions.
Epigenetic regulation of centromere formation and kinetochore functionThis paper is one of a selection of papers published in this Special Issue, entitled 27th International West Coast Chromatin and Chromosome Conference, and has undergone the Journal's usual peer review process.
Authors: Heit Ryan , Underhill D. Alan , Chan Gordon , Hendzel Michael J.
Published: August 2006

In the midst of an increasingly detailed understanding of the molecular basis of genome regulation, we still only vaguely understand the relationship between molecular biochemistry and the structure of the chromatin inside of cells. The centromere is a structurally and functionally unique region of each chromosome and provides an example in which the molecular understanding far exceeds the understanding of the structure and function relationships that emerge on the chromosomal scale. The centromere is located at the primary constriction of the chromosome. During entry into mitosis, the centromere specifies the assembly site of the kinetochore, the structure that binds to microtubules to enable transport of the chromosomes into daughter cells. The epigenetic contributions to the molecular organization and function of the centromere are reviewed in the context of structural mechanisms of chromatin function.
The nucleosome: a little variation goes a long wayThis paper is one of a selection of papers published in this Special Issue, entitled 27th International West Coast Chromatin and Chromosome Conference, and has undergone the Journal's usual peer review process.
Authors: Bernstein Emily , Hake Sandra B.
Published: August 2006

Changes in the overall structure of chromatin are essential for the proper regulation of cellular processes, including gene activation and silencing, DNA repair, chromosome segregation during mitosis and meiosis, X chromosome inactivation in female mammals, and chromatin compaction during apoptosis. Such alterations of the chromatin template occur through at least 3 interrelated mechanisms: post-translational modifications of histones, ATP-dependent chromatin remodeling, and the incorporation (or replacement) of specialized histone variants into chromatin. Of these mechanisms, the exchange of variants into and out of chromatin is the least well understood. However, the exchange of conventional histones for variant histones has distinct and profound consequences within the cell. This review focuses on the growing number of mammalian histone variants, their particular biological functions and unique features, and how they may affect the structure of the nucleosome. We propose that a given nucleosome might not consist of heterotypic variants, but rather, that only specific histone variants come together to form a homotypic nucleosome, a hypothesis that we refer to as the nucleosome code. Such nucleosomes might in turn participate in marking specific chromatin domains that may contribute to epigenetic inheritance.
Structure and function of nucleosome assembly proteinsThis paper is one of a selection of papers published in this Special Issue, entitled 27th International West Coast Chromatin and Chromosome Conference, and has undergone the Journal's usual peer review process.
Authors: Park Young-Jun , Luger Karolin
Published: August 2006

Homologues of nucleosome assembly protein 1 (NAP1) have been identified in all eukaryotes. Although initially identified as histone chaperones and chromatin-assembly factors, additional functions include roles in tissue-specific transcription regulation, apoptosis, histone shuttling, and cell-cycle regulation, and extend beyond those of a simple chaperone and assembly factor. NAP1 family members share a structurally conserved fold, the NAP domain. Here we review current knowledge of the NAP family of proteins within the context of the recently determined crystal structure of the NAP1 family's first representative, NAP1 from yeast.
Heart failure-associated alterations in troponin I phosphorylation impair ventricular relaxation-afterload and force-frequency responses and systolic function
Authors: Bilchick Kenneth C. , Duncan Jennifer G. , Ravi Rajashree , Takimoto Eiki , Champion Hunter C. , Gao Wei Dong , Stull Linda B. , Kass David A. , Murphy Anne M.
Published: August 2006

Recent studies have found that selective stimulation of troponin (Tn)I protein kinase A (PKA) phosphorylation enhances heart rate-dependent inotropy and blunts relaxation delay coupled to increased afterload. However, in failing hearts, TnI phosphorylation by PKA declines while protein kinase C (PKC) activity is enhanced, potentially augmenting TnI PKC phosphorylation. Accordingly, we hypothesized that these site-specific changes deleteriously affect both rate-responsive cardiac function and afterload dependence of relaxation, both prominent phenotypic features of the failing heart. A transgenic (TG) mouse model was generated in which PKA-TnI sites were mutated to mimic partial dephosphorylation (Ser22 to Ala; Ser23 to Asp) and dominant PKC sites were mutated to mimic constitutive phosphorylation (Ser42 and Ser44 to Asp). The two highest-expressing lines were further characterized. TG mice had reduced fractional shortening of 34.7 ± 1.4% vs. 41.3 ± 2.0% ( P = 0.018) and slight chamber dilation on echocardiography. In vivo cardiac pressure-volume studies revealed near doubling of isovolumic relaxation prolongation with increasing afterload in TG animals ( P < 0.001), and this remained elevated despite isoproterenol infusion (PKA stimulation). Increasing heart rate from 400 to 700 beats/min elevated contractility 13% in TG hearts, nearly half the response observed in nontransgenic animals ( P = 0.005). This blunted frequency response was normalized by isoproterenol infusion. Abnormal TnI phosphorylation observed in cardiac failure may explain exacerbated relaxation delay in response to increased afterload and contribute to blunted chronotropic reserve.
Heterogeneous gap junction remodeling stabilizes reentrant circuits in the epicardial border zone of the healing canine infarct: a computational study
Authors: Cabo Candido , Boyden Penelope A.
Published: August 2006

The ventricular tachycardias (VTs) that originate in the 5-day epicardial border zone (EBZ) of the healing canine infarcted heart are due to reentrant excitation. In cells surviving in the EBZ, both sarcolemmal ionic channels and gap junction conductance and distribution are remodeled. We previously showed that the heterogeneities in sodium current ( INa) and L-type calcium channel current ( ICaL) of the center and outer pathway cells result in a homogenization of the refractory period that in turn stabilizes reentrant VTs for ∼10 beats. To understand how heterogeneities in transverse gap junctional conductance remodeling reported experimentally contribute to the stability of these tachycardias, we studied the dynamics of reentering waves in two-dimensional computer models of the EBZ. First we used a computer model with homogeneous ionic channel properties [infarcted border zone cell model (IZ)]. These simulations show that, in the absence of heterogeneities in ionic channel properties, reentrant waves tend to drift to localized regions of uncoupling and stabilize there. Second, we used a computer model with a more realistic representation of the heterogeneous EBZ, including cellular models for both the center (IZc) and outer (IZo) pathway cells. These simulations show that neither a region of uniform uncoupling nor a step transition between two regions with different side-to-side (transverse) cell coupling stabilizes reentry in this substrate. However, an area of localized uncoupling did stabilize reentry in such a model. We propose that in addition to the heterogeneities in INa and ICaL properties, heterogeneities in gap junctional conductance in the EBZ causing regions of localized uncoupling stabilize VT in the EBZ. Previous experimental in situ activation maps of the 5-day EBZ show that the lines of block form in regions of slow transverse propagation. This is consistent with our findings that areas of localized uncoupling stabilize reentry.
Toll-like receptor 3 is an essential component of the innate stress response in virus-induced cardiac injury
Authors: Hardarson Hordur S. , Baker J. Scott , Yang Zhao , Purevjav Enkhsaikhan , Huang Chien-Hua , Alexopoulou Lena , Li Na , Flavell Richard A. , Bowles Neil E. , Vallejo Jesus G.
Published: August 2006

Enterovirus-induced myocardial injury can lead to severe heart failure. To date, little is known about the early innate stress response that contributes to host defense in the heart. Toll-like receptor 3 (TLR3) is important in the initiation of the innate antiviral response. We investigated the involvement of TLR3, which recognizes viral double-stranded RNA, on encephalomyocarditis virus (EMCV) infection. To examine the contribution of TLR3 in protection from EMCV infection, we infected mice deficient in TLR3 with 50 plaque-forming units of EMCV. TLR3-deficient (TLR3−/−) mice were more susceptible to EMCV infection and had a significantly higher viral load in the heart compared with TLR3+/+mice. Histopathological examination showed that the inflammatory changes of the myocardium were less marked in TLR3−/−than in TLR3+/+mice. TLR3−/−mice had impaired proinflammatory cytokine and chemokine expression in the heart following EMCV infection. However, the expression of interferon-β was not impaired in EMCV-infected TLR3−/−mice. EMCV infection leads to a TLR3-dependent innate stress response, which is involved in mediating protection against virus-induced myocardial injury.
Modeling of IK1 mutations in human left ventricular myocytes and tissue
Authors: Seemann Gunnar , Sachse Frank B. , Weiss Daniel L. , Ptáček Louis J. , Tristani-Firouzi Martin
Published: August 2006

Elucidation of the cellular basis of arrhythmias in ion channelopathy disorders is complicated by the inherent difficulties in studying human cardiac tissue. Thus we used a computer modeling approach to study the mechanisms of cellular dysfunction induced by mutations in inward rectifier potassium channel (Kir)2.1 that cause Andersen-Tawil syndrome (ATS). ATS is an autosomal dominant disorder associated with ventricular arrhythmias that uncommonly degenerate into the lethal arrhythmia torsade de pointes. We simulated the cellular and tissue effects of a potent disease-causing mutation D71V Kir2.1 with mathematical models of human ventricular myocytes and a bidomain model of transmural conduction. The D71V Kir2.1 mutation caused significant action potential duration prolongation in subendocardial, midmyocardial, and subepicardial myocytes but did not significantly increase transmural dispersion of repolarization. Simulations of the D71V mutation at shorter cycle lengths induced stable action potential alternans in midmyocardial, but not subendocardial or subepicardial cells. The action potential alternans was manifested as an abbreviated QRS complex in the transmural ECG, the result of action potential propagation failure in the midmyocardial tissue. In addition, our simulations of D71V mutation recapitulate several key ECG features of ATS, including QT prolongation, T-wave flattening, and QRS widening. Thus our modeling approach faithfully recapitulates several features of ATS and provides a mechanistic explanation for the low frequency of torsade de pointes arrhythmia in ATS.
5′-AMP-activated protein kinase activation prevents postischemic leukocyte-endothelial cell adhesive interactions
Authors: Gaskin F. Spencer , Kamada Kazuhiro , Yusof Mozow , Korthuis Ronald J.
Published: August 2006

Preconditioning (PC) with nitric oxide (NO) donors or agents that increase endothelial NO synthase (eNOS) activity 24 h before ischemia-reperfusion (I/R) prevents postischemic leukocyte rolling (LR) and stationary leukocyte adhesion (LA). Since 5′-AMP-activated protein kinase (AMPK) phosphorylates eNOS at Ser1177, resulting in activation, we postulated that AMPK activation may trigger the development of a preconditioned anti-inflammatory phenotype similar to that induced by NO donors. Wild-type (WT) C57BL/6J and eNOS−/−mice were treated with the AMPK agonist 5-aminoimidazole-4-carboxamide 1-β-d-furanoside (AICAR) 30 min (early AICAR PC) or 24 h (late AICAR PC) before I/R; LR and LA were quantified in single postcapillary venules in the jejunum using intravital microscopy. I/R induced comparable marked increases in LR and LA in WT and eNOS−/−mice relative to sham-operated (no ischemia) animals. Late AICAR PC prevented postischemic LR and LA, whereas early AICAR PC prevented LA in WT mice. Late AICAR PC was ineffective in preventing I/R-induced LR but not LA in the eNOS−/−mice, and the same pattern was seen in WT animals treated with the NOS inhibitor Nω-nitro-l-arginine. Early AICAR PC remained effective in preventing LA in eNOS−/−mice. Our results indicate that both early and late PC with an AMPK agonist produces an anti-inflammatory phenotype in postcapillary venules. Since the protection afforded by late AICAR PC on postischemic LR was prevented by NOS inhibition in WT mice and absent in eNOS-deficient mice, it appears that eNOS triggers this protective effect. In stark contrast, antecedent AMPK activation prevented I/R-induced LA by an eNOS-independent mechanism.
Effect of IL-6 trans-signaling on the pro-remodeling phenotype of airway smooth muscle
Authors: Ammit Alaina J. , Moir Lyn M. , Oliver Brian G. , Hughes J. Margaret , Alkhouri Hatem , Ge Qi , Burgess Janette K. , Black Judith L. , Roth Michael
Published: August 2006

Increased levels of IL-6 are documented in asthma, but its contribution to the pathology is unknown. Asthma is characterized by airway wall thickening due to increased extracellular matrix deposition, inflammation, angiogenesis, and airway smooth muscle (ASM) mass. IL-6 binds to a specific membrane-bound receptor, IL-6 receptor-α (mIL-6Rα), and subsequently to the signaling protein gp130. Alternatively, IL-6 can bind to soluble IL-6 recpetor-α (sIL-6Rα) to stimulate membrane receptor-deficient cells, a process called trans-signaling. We discovered that primary human ASM cells do not express mIL-6Rα and, therefore, investigated the effect of IL-6 trans-signaling on the pro-remodeling phenotype of ASM. ASM required sIL-6Rα to activate signal transducer and activator 3, with no differences observed between cells from asthmatic subjects compared with controls. Further analysis revealed that IL-6 alone or with sIL-6Rα did not induce release of matrix-stimulating factors (including connective tissue growth factor, fibronectin, or integrins) and had no effect on mast cell adhesion to ASM or ASM proliferation. However, in the presence of sIL-6Rα, IL-6 increased eotaxin and VEGF release and may thereby contribute to local inflammation and vessel expansion in airway walls of asthmatic subjects. As levels of sIL-6Rα are increased in asthma, this demonstration of IL-6 trans-signaling in ASM has relevance to the development of airway remodeling.
Redundant Toll-like receptor signaling in the pulmonary host response toPseudomonas aeruginosa
Authors: Skerrett Shawn J. , Wilson Christopher B. , Liggitt H. Denny , Hajjar Adeline M.
Published: August 2006

Activation of pulmonary defenses against Pseudomonas aeruginosa requires myeloid differentiation factor 88 (MyD88), an adaptor for Toll-like receptor (TLR) signaling. To determine which TLRs mediate recognition of P. aeruginosa, we measured cytokine responses of bone marrow cells from wild-type mice and mice lacking TLR2 (TLR2−/−), TLR4 (TLR4−/−), TLR2 and TLR4 (TLR2/4−/−), or MyD88 (MyD88−/−) to wild-type P. aeruginosa and to fliC P. aeruginosa, which lacks the TLR5 ligand flagellin. Mice also were challenged with aerosolized bacteria to determine cytokine responses, lung inflammation, and bacterial clearance. TNF induction required MyD88 and was absent in TLR2/4−/−cells in response to fliC but not wild-type P. aeruginosa, whereas TLR2−/−cells exhibited augmented responses. In vivo, TLR4−/−mice responded to wild-type P. aeruginosa with reduced cytokine production and inflammation, but intact bacterial clearance, while TLR2−/−mice had partially impaired cytokine responses and delayed bacterial killing despite normal inflammation. When challenged with fliC, MyD88−/−mice failed to mount early cytokine and inflammatory responses or control bacterial replication, resulting in necrotizing lung injury and lethal disseminated infection. TLR4−/−and TLR2/4−/−mice responded to fliC infection with severely limited inflammatory and cytokine responses but intact bacterial clearance. TLR2−/−mice had partially reduced cytokine responses but augmented inflammation and preserved bacterial killing. These data indicate that TLR4- and flagellin-induced signals mediate most of the acute inflammatory response to Pseudomonas and that TLR2 has a counterregulatory role. However, MyD88-dependent pathways, in addition to those downstream of TLR2, TLR4, and TLR5, are required for pulmonary defense against P. aeruginosa.
Toxicity of PAHs and jelly protection of eggs in the Common frog Rana temporaria
Authors: Marquis Olivier , Guittonneau Sylvie , Millery Annie , Miaud Claude
Published: August 2006

Polycyclic Aromatic Hydrocarbons (PAHs) are damaging for aquatic organisms such as amphibians. In this study, toxicity of a mixture of three PAHs (naphthalene (2 rings), phenanthrene (3 rings) and pyrene (4 rings)) was tested on Common frog (Rana temporaria) embryos. The protective role of the jelly coat surrounding the eggs was studied by exposing embryos with and without jelly coat to PAHs dissolved in an aqueous solution without organic solvent. Results showed that the mixture of these three PAHs significantly increase embryonic mortality rate after a few hours of exposure. Embryos with jelly coat tend to suffer a lower mortality rate than embryos without jelly. The jelly surrounding eggs is filled by water of the breeding site, which can contain pollutants. Because jelly characteristics vary among species, sensitivity to environmental pollutants and levels of embryonic protection could be different among amphibian species.
New parental care behaviours in two telmatobiine genera from temperate Patagonian forests: Batrachyla and Eupsophus (Anura: Leptodactylidae)
Authors: Úbeda Carmen , Nuñez José
Published: August 2006

Parental care behaviour is described for the first time for two frog species of Batrachyla and three species of Eupsophus, from the Patagonian forests of Chile and Argentina. Males of Batrachyla species attend to eggs which are hidden under shelters on damp soil. Males of Eupsophus species remain by the clutch, and later on also by the tadpoles, in small aquatic microhabitats in the ground. The fact that some male of Eupsophus were found in advanced stages of weight loss confirms the hypothesis that they remain by the clutch until metamorphosis takes place. The parental care behaviour observed in Eupsophus and Batrachyla complements the reproductive strategy of their species, which have few eggs relatively rich in yolk and conceal the clutch in semi-terrestrial environments, and in Eupsophus, have unpigmented endotrophic tadpoles which remain confined to a dark, aquatic microhabitat until their metamorphosis is complete.
Phylogeography of the genus Blanus (worm lizards) in Iberia and Morocco based on mitochondrial and nuclear markers — preliminary analysis
Authors: Vaconcelos Raquel , Harris D. James , Carretero Miguel
Published: August 2006

The evolutionary relationships of amphisbaenians of the genus Blanus have long been controversial. Presently two species are recognized for Morocco — Blanus tingitanus and B. mettetali and one for Iberia — B. cinereus. Using mitochondrial and nuclear DNA sequences, 25 samples from Portugal, Spain and Morocco were analysed. Both markers indicate the existence of three well-separated clades: one for the Northern Moroccan samples, corresponding to B. tingitanus and two to the B. cinereus samples. One sample from Taza, Morocco, was identical to specimens from one of the Iberian forms. These results point to the necessity of a systematic revision. These new groups reinforce the need for geographically broader sampling accompanied by morphological studies to fully determine the phylogenetic history of this species complex.
A new snake of the genus Tropidophis (Tropidophiidae) from the Guanahacabibes Peninsula of Western Cuba
Authors: Moreno Luis , Hedges S. Blair , Domínguez Michel
Published: August 2006

Tropidophis xanthogaster, new species, is described from Guanahacabibes Peninsula, Pinar del Río Province, Cuba. It has a grayish-brown or greenish-gray dorsum with eight rows of dark brown spots and a yellow venter which lacks spots on the anterior one-third. It is placed in the pardalis group mainly because of its small size, low number of ventral scales (155-164), eight spot rows, and 23 scale rows at midbody. It differs from its closest relative, T. pardalis, by a combination of color, pattern, and scale differences.
Why do males and females of Python regius differ in ectoparasite load?
Authors: Luiselli Luca
Published: August 2006

A recent study of Python regius from Togo (Aubret et al., 2005) has demonstrated that male pythons suffered for a much higher ectoparasite load than the females. The authors hypothesized that these intersexual differences may depend on increased male movements in the mating season relative to females, thus increasing their chances of meeting with ectoparasites. On the other hand, they suggested that differences in habitat use are unlikely to explain this pattern because males and females are found within the same type of burrows. Based on previously published data on food habits of P. regius in Nigeria, as well as on radiotracking data, I showed that males were more arboreal-dwelling than females. I suggest that ectoparasite load differences between sexes depend on a different use of the space, with males being more arboreal than females, and hence collecting ticks from low tree-branches as well as from the ground levels, whereas the same is less true for the females which are infested mainly by the terrestrial ticks.
Assessing the phylogenetic signal of the nuclear β-Fibrinogen intron 7 in salamandrids (Amphibia: Salamandridae)
Authors: Sequeira Fernando , Ferrand Nuno , Harris D. James
Published: August 2006

The potential of the seventh intron of the β-subunit of the fibrinogen gene (β-fibint 7) for phylogenetic analysis within the Salamandridae family was explored, comparing the topologies of trees based on this marker to those based on mitochondrial 12S rRNA gene previously published. Using primers designed specifically for amphibians, we amplified 25 sequences of β-fibint 7 corresponding to 15 species of salamandrids and one plethodontid species. There was considerable length variation among the β-fibint 7 sequences examined, ranging from 1123 bp in S. atra to 400 bp in P. waltl. Many aspects of the phylogenetic relationships estimated by the two independent loci were congruent and corroborate current taxonomic hypothesis. Although the number of taxa analysed is small, the data obtained in this work suggested that β-fibint 7 is a useful marker for assessing phylogenetic relationships within the Salamandridae family, and is probably appropriate for phylogenetic studies among closely related salamanders that have diverged over the last 20 Myr.
A Relational Turbulence Model of Communication About Irritations in Romantic Relationships
Authors: Theiss Jennifer A. , Solomon Denise Haunani
Published: August 2006

The authors examined the impact of intimacy, relational uncertainty, and a partner’s interference on the directness of communication about relational irritations. The authors hypothesized that directness has (a) a positive association with the perceived negativity of irritations, intimacy, and self uncertainty; (b) a negative association with relationship uncertainty; (c) a negative association with partner uncertainty that is mediated by relationship uncertainty; and (d) a positive association with a partner’s interference that is mediated by the perceived negativity of irritations. The authors conducted a longitudinal Web-based survey in which individuals in romantic associations reported on qualities of their relationships once per week for 6 weeks. A structural equation model of data from the first week was consistent with the authors’ hypotheses. Longitudinal analyses of the full data set using hierarchical linear modeling provided mixed support for the authors’ predictions. The article discusses the implications of the findings for understanding both communicative directness and turbulence within developing dating relationships.
Do Prior Trauma and Victimization Predict Weapon Carrying Among Delinquent Youth?
Authors: Vaughn Michael G. , Howard Matthew O. , Harper-Chang Lisa
Published: August 2006

This investigation tested whether weapon carrying is a response to a perceived threat posed by prior victimization and traumatic experiences in a state population of incarcerated youth. Structured interviews of 723 youth (ageM = 15.5,SD = 1.23; 87% male) residing in all Missouri Division of Youth Services facilities were conducted. Multivariate analyses revealed that although prior victimization and trauma did increase the likelihood of weapon carrying, the probability of weapon carrying was higher with respect to gang fighting and polysubstance use. And although prior victimization and trauma did possess incremental validity in predicting weapon carrying, having been in a gang fight and lifetime polysubstance use were more potent predictors of weapon carrying. Results provide clear social policy implications in that strategies capable of reducing gang involvement and substance abuse may in turn interrupt the cycle of violence via the mechanism of weapon carrying reduction in high-risk youth.
Preliminary Findings from an Outcome Evaluation of an Intimate Partner Violence Prevention Program for Adjudicated, African American, Adolescent Males
Authors: Salazar Laura F. , Cook Sarah L.
Published: August 2006

This study evaluated the efficacy of a five-session intimate partner violence (IPV) prevention program for adjudicated African American male adolescents. The program was guided by feminist theory and was culturally focused and gender specific. An experimental design was used to assess changes in knowledge of IPV and patriarchal attitudes at posttest and to test for the moderating effects of committing IPV and witnessing parental IPV. Results indicated higher levels of knowledge and less patriarchal attitudes among the intervention group as compared to the control group. Committing violence was not a significant moderator of intervention effectiveness; a witnessing parental violence by group interaction revealed that adolescents in the intervention group had significantly lower patriarchal attitudes compared with adolescents in the control group, but only for those who witnessed high levels of parental male-to-female violence.
Nozzle-Adjuvant Formulation Interactions: Implications on Herbicide Efficacy
Authors: McMullan PM , Thurman S , McManic G , Brigance M
Published: August 2006

A series of adjuvants were developed to improve herbicide performance when applied through air induction nozzles. A series of research trials were conducted in 2004 and 2005 with clethodim, foramsulfuron, and glyphosate. Efficacy of these herbicides was reduced in over 30 % of all cases when applied through air induction nozzles compared to conventional flatfan nozzles. However, when modified forms of the adjuvants were used, efficacy increased approximately 25 % of cases with glyphosale, 40 % of cases with clethodim, and 90 % of cases with foramsulfuron when using air induction nozzles. A separate series of oil-based adjuvants developed had over 20 % air entrapment whereas conventional oil-based adjuvants had 5 % or less air entrapment when using air induction nozzles. Research conducted in the field in 2005 indicated that these novel formulations may improve herbicide efficacy.
Effect of Dynamic Aircraft Gear Loads on Asphalt Concrete Strain Responses
Authors: Gopalakrishnan K , Thompson MR
Published: August 2006

Asphalt strain gauges were installed in both the longitudinal and transverse directions at the Federal Aviation Administration's National Airport Pavement Test Facility (NAPTF) to measure the load-induced Asphalt Concrete (AC) tensile strains during full-scale traffic testing with a dual-tridem Boeing 777 gear configuration and a dual-tandem Boeing 747 gear configuration. The results are presented for four flexible test sections; two sections with 127 mm of AC and two with 254 mm of AC. An axisymmetric finite element pavement analysis software was used to model the NAPTF flexible test sections and compute the AC strain responses. The measured AC strain magnitudes were significantly influenced by AC temperature variations. Dramatic increase in peak strain responses were observed as the NAPTF flexible test sections approached structural failure. There was a good agreement between the field-measured and computed strains during the early life of the test sections.
Nitrogen Mobility in Biosolid‐Amended Glaciated Soil
Authors: Nikolaidis Nikolaos P. , Chheda Pradeep , Lackovic Jeffrey A. , Guillard Karl , Simpson Barbara , Pedersen Tom
Published: August 2006

The potential leaching and availability of nitrogen in biosolids and biosolid‐amended glaciated soil were investigated using mineralization and column studies. Aerobic and anaerobic mineralization studies were conducted to assess nitrogen mineralization potential from biosolid‐amended glaciated soils and estimate long‐ and short‐term mineralization rates of products. Semicontinuous column studies were conducted to assess the leachability of nitrogen from biosolid‐amended soil under simulated unsaturated soil conditions. This study used a Paxton soil because its characteristics are typical of glaciated soil found in New England. Three types of biosolids, which are representative of biosolids currently available in Connecticut, were evaluated: composted biosolids (compost), cement kiln dust stabilized (CKD) biosolids, and heat‐dried biosolids (pellet). Results indicate that the pellet product had the greatest mineralization potential (based on unmixed biosolids) at 5 317 mg N/kg, followed by compost (324 mg N/kg) and CKD biosolids (58 mg N/kg). Nitrogen mineralized for the anaerobic test (mixed with soil) varied from 56 to 90% of the total nitrogen and for the aerobic test varied from 19 to 57%. The CKD biosolids percolate consisted primarily of nitrate and nitrite, whereas the predominant nitrogen species found in compost and pellet biosolids percolate was ammonium. Results suggest that one‐time application of biosolids at agronomic or liming rates (whichever is limiting) will cause minimal effects to groundwater.
The Effect of Low Temperatures on Ammonia Removal in a Laboratory‐Scale Constructed Wetland
Authors: Lee M.A. , Stansbury J.S. , Zhang T.C.
Published: August 2006

The effect of low temperatures on ammonia removal in constructed wetlands was studied by running a synthetic wastewater through a model, laboratory‐scale gravel‐filled constructed wetland (in which no plants were grown). The wetland was operated at temperatures of 5, 11.5, 15, and 23 °C in an environmentally controlled chamber. An influent ammonia concentration of 45 mg/L as nitrogen was used to simulate typical domestic wastewater. For temperatures of 5, 11.5, 15, and 23 °C, the wetland model achieved ammonia removal and nitrification of 45, 44, 56, and 65%, respectively. Thus, over the 18 °C temperature range ammonia‐nitrogen removal and nitrification rates varied only 20%. There was a net decrease in nitrogen as water passed through the wetland; this could be the result of cell growth or denitrification. Measurements were taken at the inlet, outlet, and four additional locations along the length of the reactor. Measurements were also taken at three different depths. Along the length of the reactor, nearly all nitrification was achieved in the first half of the reactor, then stopped because of low dissolved oxygen concentrations. Nitrification occurred slightly faster at the top of the reactor than at the bottom.
Kinetics of p‐Aminoazobenzene Degradation by Bacillus subtilis Under Denitrifying Conditions
Authors: Zissi Urania S. , Kornaros Michael E. , Lyberatos Gerasimos C.
Published: August 2006

Bacillus subtilis is an organism capable of degrading an azo dye, such as p‐aminoazobenzene (pAAB), under both aerobic and anoxic conditions. In both cases, pAAB is co‐metabolized with a main carbon source and under anoxic conditions denitrification is observed. Kinetic experiments were carried out with a pure culture of B. subtilis and a mathematical model that accurately describes both biodegradation of pAAB under anoxic conditions and the denitrification process under both carbon‐ and nitrate‐ or nitrite‐limited conditions is developed. Presence of pAAB in culture medium causes an inhibition of bacterial growth and of nitrite accumulation. Bacterial growth and pAAB degradation rates are found to be slower under anoxic conditions compared to the corresponding rates under aerobic conditions.