bluuebunny/crossref_metadata_2025 huggingface dataset:
Insulin‐like growth factor‐1 in psoriatic plaques treated with PUVA and methotrexate
Authors: El‐Komy M. , Amin I. , Zidan A. , Kadry D. , Zeid O.A. , Shaker O.
Published: January 2011

Background  The pathogenesis of psoriasis is thought to depend on the activation of immune cells and their secreted cytokines, chemokines and growth factors like IGF‐1 which may contribute to the epidermal hyperplasia of psoriasis. Treatment of psoriasis with PUVA and methotrexate are associated with clinical improvement and decrease in epidermal hyperplasia.

Objective  To examine the effects of PUVA and methotrexate therapy on IGF‐1 expression in psoriatic plaques and whether this change correlates with clinical response.

Methods  For 24 psoriatic patients, the PASI score and levels of lesional IGF‐1 and its mRNA were determined by RT‐PCR before and after treatment with either methotrexate or PUVA. Skin biopsies from 12 healthy volunteers served as control for IGF‐1 levels in normal skin.

Results  Lesional skin of psoriatic patients showed a statistically significant elevation in IGF‐1 and its mRNA levels in comparison to control (P = 0.0001). Both methotrexate and PUVA treatment were associated with a significant decrease in both PASI scores and lesional IGF‐1 after 10 month treatment.

Conclusion  Both methotrexate and PUVA therapy for psoriasis are associated with a decrease in PASI score and IGF‐1. The IGF‐1 down‐regulation may possibly be a consequence of the decrease in cytokines and inflammatory cellular infiltrate that occur following treatment with either modalities or due to their effect on local fibroblast activity and proliferation.
The chimera of national identity
Authors: MALEŠEVIĆ SINIŠA
Published: January 2011

ABSTRACT.In both popular discourse and many academic works, the existence of national identity is largely taken as given. Although researchers disagree on whether national identities are modern or perennial, and how best to gauge the intensity of identification with a particular nation, there is near unanimity on the view that national identities are real and perceptible entities. In contrast to this view I argue not only that there was no national identity before modernity but also that there is little empirical evidence for the existence of national identities in the modern age either. While it is obvious that many individuals show great affinity for their nations and often express sincere devotion to the ‘national cause’, none of these are reliable indicators of the existence of a durable, continuous, stable and monolithic entity called ‘national identity’. To fully understand the character of popular mobilisation in modernity it is paramount to refocus our attention from the slippery and non‐analytical idiom of ‘identity’ towards well‐established sociological concepts such as ‘ideology’ and ‘solidarity’. In particular, the central object of this research becomes the processes through which large‐scale social organisations successfully transform earnest micro‐solidarity into an all‐encompassing nationalist ideology.
Adaptability and vulnerability of high flying Neotropical aerial insectivorous bats to urbanization
Authors: Jung Kirsten , Kalko Elisabeth K. V.
Published: January 2011

Aim  Urbanization is a dominant demographic trend throughout the world that involves massive habitat alterations. Understanding how urbanization affects biota is a crucial prerequisite for development and application of effective species conservation programmes. Our study focuses on Neotropical high flying aerial insectivorous bats, an ecologically important, but so far seriously understudied group of vertebrates.

Location  Panama.

Methods  Using acoustic monitoring, we assessed and compared species occurrence, composition and activity of aerial insectivorous bats at three site categories located on the isthmus in Panama: forest, urban areas and a forest–town interface.

Results  In 2 years of field work, we recorded 44,744 bat passes over the microphone and identified a total of 25 aerial insectivorous bat species. Species richness was highest in the forest, decreased towards the forest–town interface and was lowest at the urban sites, while dominance (Berger‐Parker‐Index) increased from the forest to the urban sites. Overall, general bat activity (passes min−1) was highest at the forest–town interface and lowest at the urban sites. Multivariate analysis suggests compositional differences in species occurrence and activity among site categories with mainly molossid species occurring in urban areas.

Main conclusions  Our results clearly demonstrate species‐specific differences between high flying aerial insectivorous bats concerning their adaptability and vulnerability to urban areas. Our results suggest that a suite of morphological traits including species mobility determine persistence of aerial insectivorous species in cities. Our results underline the necessity for detailed assessments of species‐specific habitat requirements and dynamics of species occurrence and activity over time to develop meaningful conservation tools targeted at aerial insectivorous bats.
Blood gas analysis and cooximetry in retired racing Greyhounds
Authors: Zaldivar‐Lopez Sara , Chisnell Hope K. , Couto C. Guillermo , Westendorf‐Stingle Nicole , Marin Liliana M. , Iazbik Maria C. , Cooper Edward S. , Wellman Maxey L. , Muir III William W.
Published: January 2011

Objective –The purposes of this study were to evaluate the oxygen affinity of hemoglobin (Hb) in healthy retired racing Greyhounds via cooximetry, and to establish reference intervals for blood gases and cooximetry in this breed.

Design –Prospective clinical study.

Setting –University Teaching Hospital.

Animals –Fifty‐seven Greyhounds and 30 non‐Greyhound dogs.

Interventions –Venous blood samples were collected from the jugular vein and placed into heparinized tubes. The samples were analyzed within 30 minutes of collection using a blood gas analyzer equipped with a cooximeter.

Measurements and Main Results –Greyhounds had significantly higher pH, PO2, oxygen saturation, oxyhemoglobin, total Hb, oxygen content, and oxygen capacity and significantly lower deoxyhemoglobin and P50when compared with non‐Greyhound dogs.

Conclusion –These findings support the fact that this breed is able to carry a higher concentration of total oxygen in the blood. As reported previously, this breed also has lower P50and, therefore, high oxygen affinity. In light of recent findings suggesting that in certain tissues a high affinity for oxygen is beneficial, this adaptation may be of benefit during strenuous exercise.
The Duty to Take Care: President Obama, Public Administration, and the Capacity to Govern
Authors: Cooper Phillip J.
Published: January 2011

President Barack Obama inherited many challenges as he entered the White House. One of the most important obligations he faced was the constitutional duty to “take care that the laws be faithfully executed.” Meeting that commitment has been rendered more difficult because Obama seems not to have recognized that the people and organizations of the executive branch are facing a crisis in the capacity to govern. This essay argues that no matter how talented President Obama may be in public policy or on the stump, he likely will not accomplish his constitutional duty unless he engages that capacity crisis.
Trends in the Study of Public Administration: Empirical and Qualitative Observations from Public Administration Review, 2000–2009
Authors: Raadschelders Jos C. N. , Lee Kwang‐Hoon
Published: January 2011

What are the apparent research and methodological trends in PAR’s content over the past decade? From the perspective of the journal’s 70‐year history, with its aim to “mesh” practitioner and academic knowledge creation, topical coverage since 2000 reflects striking continuity, emphasizing many of the “bread and butter” administrative issues such as planning, human resources, budgeting, and public management. A marked increase in coverage is apparent in the application of more sophisticated quantitative statistical methodology, as well as in the number of female authors, while the number of practitioner authors declined sharply. Throughout the first turbulent decade of the twenty‐first century, three intellectual themes stood out: evaluations of New Public Management, connections between practitioners and academicians, and responsiveness to immediate social, economic, and political challenges. Given the constant demand for usable knowledge, scholars seem to have marginalized attention to the historical context and epistemological foundations of the study. The central challenge in the years ahead will be to effectively use research methods in response to the big questions of government and society that defy measurement.

Since many [empiricists], especially the younger, do not know very much about epistemology, they tend to be quite dogmatic about the one set of canons that dominate them.

—C. Wright Mills, 1959
Soldiers to Citizens: The Link between Military Service and Volunteering
Authors: Nesbit Rebecca , Reingold David A.
Published: January 2011

Research shows that military service is linked with political engagement, such as voting. This connection is strongest for minorities. The authors explore the relationship between military service and volunteering. They conclude that military service helps overcome barriers to volunteering by socializing people with civic responsibility norms, by providing social resources and skills that compensate for the lack of personal resources, and by making veterans aware of opportunities to volunteer as well as asking them to do so. Military service is positively related to volunteering among blacks and Hispanics. Married veterans are more likely to volunteer than nonveterans. Veterans who served during wartime are more likely to volunteer than those who served in peacetime.
Public Administration as an Interdisciplinary Field: Assessing Its Relationship with the Fields of Law, Management, and Political Science
Authors: Wright Bradley E.
Published: January 2011

Public administration is an interdisciplinary field, building on a variety of disciplinary approaches and values. But how well does the field of public administration reflect those values and processes? In contrast to previous arguments regarding the degree to which the field does or should incorporate values and lessons from other academic disciplines, this study provides a systematic assessment of the field’s reliance on research and theory from the fields of law, management, and political science. An analysis of journal citations across these fields suggests that research in public administration is largely isolated from the three disciplines that are commonly believed to form its foundation.
Origins of Electro‐Mechanical Coupling in Polycrystalline Ferroelectrics During Subcoercive Electrical Loading
Authors: Pramanick Abhijit , Damjanovic Dragan , Daniels John E. , Nino Juan C. , Jones Jacob L.
Published: January 2011

The electromechanical coupling in ferroelectric materials is controlled by several coexisting structural phenomena which can include piezoelectric lattice strain, 180° and non‐180° domain wall motion, and interphase boundary motion. The structural mechanisms that contribute to electromechanical coupling have not been readily measured in the past, particularly under the low‐to‐medium driving electric field amplitudes at which many piezoelectric materials are used. In this feature, results from in situ, high‐energy, and time‐resolved X‐ray diffraction experiments are interpreted together with macroscopic piezoelectric coefficient measurements in order to better understand the contribution of these mechanisms to the electromechanical coupling of polycrystalline ferroelectric materials. The compositions investigated include 2 mol% La‐doped PbZr0.60Ti0.40O3, 2 mol% La‐doped PbZr0.52Ti0.48O3, 2 mol% La‐doped PbZr0.40Ti0.60O3, undoped PbZr0.52Ti0.48O3, and 2 mol% Fe‐doped PbZr0.47Ti0.53O3. In all compositions, a strong correlation is found between the field‐amplitude‐dependence of the macroscopic piezoelectric coefficient and the contribution of non‐180° domain wall motion determined from the diffraction data. The results show directly that the Rayleigh‐like behavior of d33 piezoelectric coefficient is predominantly due to a Rayleigh‐like behavior of non‐180° domain wall motion. Furthermore, after separating contributions from lattice (atomic level) and domain wall motion (nanoscale level) to the measured macroscopic piezoelectric properties, we show that previously ignored intergranular interactions (microscopic level) account for a surprisingly large portion of the electromechanical coupling. These results demonstrate that electromechanical coupling in polycrystalline aggregates is substantially different from that observed in single crystalline materials. The construct of emergence is used to describe how averaged macrolevel phenomena are different from the material response observed in an isolated subcomponent of the material. Consequently, and due to its size‐scale complexity, the description of grain‐to‐grain interactions is presently inaccessible in most ab initio and phenomenological approaches. Results presented here demonstrate the need to account for these interactions in order to completely describe macroscopic electromechanical properties of polycrystalline materials.
Parenting Coordination: The Risks of a Hybrid Conflict Resolution Process
Authors: Barsky Allan E.
Published: January 2011

Parenting coordination is a conflict resolution process that blends the roles of mediator, decision maker, monitor, assessor, educator, counselor, and enforcer for families involved in high‐conflict divorces. This article explores the potential benefits and risks of blending roles in terms of efficiency, effectiveness, trust, posturing, dual roles, self‐determination, and allegations of bias.
Female Infertility Related to Thyroid Autoimmunity: The Ovarian Follicle Hypothesis
Authors: Monteleone Patrizia , Parrini Donatella , Faviana Pinuccia , Carletti Elena , Casarosa Elena , Uccelli Alessia , Cela Vito , Genazzani Andrea Riccardo , Artini Paolo Giovanni
Published: January 2011

Citation  Monteleone P, Parrini D, Faviana P, Carletti E, Casarosa E, Uccelli A, Cela V, Genazzani AR, Artini PG. Female infertility related to thyroid autoimmunity: the ovarian follicle hypothesis. Am J Reprod Immunol 2011; 66: 108–114

Problem  The aim of this study was to verify whether anti‐thyroid antibodies are present in the follicular milieu of euthyroid infertile women with thyroid autoimmunity undergoing in vitro fertilization (IVF) and whether IVF outcome is different in affected women with respect to negative controls. A secondary endpoint was to check whether there are changes in thyroid hormone levels during the IVF cycle.

Method of study  Anti‐thyroglobulin and anti‐thyroperoxidase levels were measured in both follicular fluid and serum on the day of oocyte retrieval in women with thyroid autoimmunity. Serum TSH, FT3, and FT4 levels were measured in all patients before treatment initiation, on the day of oocyte retrieval and of pregnancy test. IVF outcome parameters were recorded in all women.

Results  Oocyte fertilization, grade A embryos, and pregnancy rates were lower in women with thyroid autoimmunity than in negative controls, while early miscarriage rate was higher. Anti‐thyroid antibodies were measurable in follicular fluid in all affected women and were strongly correlated with serum levels. No significant changes in thyroid hormone levels were recorded in any women.

Conclusion  The presence of anti‐thyroid antibodies in ovarian follicles, as demonstrated for the first time in this study, may play a critical role in female infertility related to thyroid autoimmunity.
Breast cancer risk among patients with Klinefelter syndrome
Authors: Brinton Louise A
Published: January 2011

Aim:  To evaluate male breast cancer (MBC) risk among patients with Klinefelter syndrome (KS) and relate this to possible biological explanations.

Methods:  A literature review was conducted to identify case series and epidemiologic studies that have evaluated MBC risk among patients with KS.

Results:  Case reports without expected values have often led to false impressions of risk. Problems include that a diagnosis of cancer can prompt a karyotypic evaluation and that many cases of KS are unrecognized, resulting in incomplete denominators. Few carefully conducted epidemiologic studies have been undertaken given that both KS and MBC are rare events. The largest study found 19.2‐ and 57.8‐fold increases in incidence and mortality, respectively, with particularly high risks among 47,XXY mosaics. These risks were still approximately 70% lower than among females, contradicting case reports that patients with KS have breast cancer rates similar to females. Altered hormone levels (especially the ratio of oestrogens to androgens), administration of exogenous androgens, gynaecomastia and genetic factors have been offered as possible explanations for the high risks.

Conclusions:  Additional well‐designed epidemiologic studies are needed to clarify which patients with KS are at a high risk of developing MBC and to distinguish between possible predisposing factors, including altered endogenous hormones.
Transcutaneous blood gas monitoring during neonatal intensive care
Authors: Sandberg Kenneth L , Brynjarsson Hrolfur , Hjalmarson Ola
Published: January 2011

Aim:  To evaluate the accuracy in transcutaneous (Tc) blood gas monitoring in newborn infants, including extremely low birth weight infants, during neonatal intensive care.

Methods:  Tc PO2/PCO2 was monitored in the neonatal intensive care unit (NICU) during stable infant conditions. In comparison, simultaneous arterial PO2 and PCO2 was measured. Sixty measurements were taken in 46 infants with median (range) birth weight of 0.93 (0.53–4.7) kg and at median (range) age of 8.5 (1–44) days. Comparison of measurements was performed using Bland–Altman plots, and the mean (95% CI) of the difference was calculated. Comparison was also performed in relation to body weight, postnatal age and oxygen requirement.

Results:  The mean (95% CI) difference in PO2 (TcPO2–aPO2) was 0.3 (−0.2–0.9) kPa, and the corresponding difference in PCO2 (TcPCO2–aPCO2) was 0.4 (0.03–0.8, p < 0.05) kPa. Some differences were related to body weight, age and oxygen requirement, but these differences were small.

Conclusion:  There was good agreement between TcPO2/TcPCO2 and corresponding arterial measurements. The mean difference between the methods was small and clinically acceptable in a current NICU. Tc blood gas monitoring could be recommended as a valuable complement for blood gas monitoring also in extremely low birth weight infants.
Identification of Ewing’s sarcoma protein as a G‐quadruplex DNA‐ and RNA‐binding protein
Authors: Takahama Kentaro , Kino Katsuhito , Arai Shigeki , Kurokawa Riki , Oyoshi Takanori
Published: January 2011

The Ewing’s sarcoma (EWS) oncogene contains an N‐terminal transcription activation domain and a C‐terminal RNA‐binding domain. Although the EWS activation domain is a potent transactivation domain that is required for the oncogenic activity of several EWS fusion proteins, the normal role of intact EWS is poorly characterized because little is known about its nucleic acid recognition specificity. Here we show that the Arg‐Gly‐Gly (RGG) domain of the C‐terminal in EWS binds to the G‐rich single‐stranded DNA and RNA fold in the G‐quadruplex structure. Furthermore, inhibition of DNA polymerase on a template containing a human telomere sequence in the presence of RGG occurs in an RGG concentration‐dependent manner by the formation of a stabilized G‐quadruplex DNA–RGG complex. In addition, mutated RGG containing Lys residues replacing Arg residues at specific Arg‐Gly‐Gly sites and RGG containing Arg methylated by protein arginine N‐methyltransferase 3 decrease the binding ability of EWS to G‐quadruplex DNA and RNA. These findings suggest that the RGG of EWS binds to G‐quadruplex DNA and RNA via the Arg residues in it.
Application of a New Vertical Profiling Tool (ESASS) for Sampling Groundwater Quality During Hollow‐Stem Auger Drilling
Authors: Harte Philip T. , Flanagan Sarah M.
Published: January 2011

A new tool called ESASS (Enhanced Screen Auger Sampling System) was developed by the U.S. Geological Survey. The use of ESASS, because of its unique U.S. patent design (U.S. patent no. 7,631,705 B1), allows for the collection of representative, depth‐specific groundwater samples (vertical profiling) in a quick and efficient manner using a 0.305‐m long screen auger during hollow‐stem auger drilling. With ESASS, the water column in the flights above the screen auger is separated from the water in the screen auger by a specially designed removable plug and collar. The tool fits inside an auger of standard inner diameter (82.55 mm). The novel design of the system constituted by the plug, collar, and A‐rod allows the plug to be retrieved using conventional drilling A‐rods. After retrieval, standard‐diameter (50.8 mm) observation wells can be installed within the hollow‐stem augers. Testing of ESASS was conducted at one waste‐disposal site with tetrachloroethylene (PCE) contamination and at two reference sites with no known waste‐disposal history. All three sites have similar geology and are underlain by glacial, stratified‐drift deposits. For the applications tested, ESASS proved to be a useful tool in vertical profiling of groundwater quality. At the waste site, PCE concentrations measured with ESASS profiling at several depths were comparable (relative percent difference <25%) to PCE concentrations sampled from wells. Vertical profiling with ESASS at the reference sites illustrated the vertical resolution achievable in the profile system; shallow groundwater quality varied by a factor of five in concentration of some constituents (nitrate and nitrite) over short (0.61 m) distances.
Synthesis and Biological Evaluation of New Quinoxaline Derivatives as Antioxidant and Anti‐Inflammatory Agents
Authors: Burguete Asunción , Pontiki Eleni , Hadjipavlou‐Litina Dimitra , Ancizu Saioa , Villar Raquel , Solano Beatriz , Moreno Elsa , Torres Enrique , Pérez Silvia , Aldana Ignacio , Monge Antonio
Published: January 2011

We report the synthesis, anti‐inflammatory, and antioxidant activities of novel quinoxaline and quinoxaline 1,4‐di‐N‐oxide derivatives. Microwave‐assisted methods have been used to optimize reaction times and to improve yields. The tested compounds presented important scavenging activities and promising in vitro inhibition of soybean lipoxygenase (LOX). Two of the best LOX inhibitors (compounds 7b and 8f) were evaluated as in vivo anti‐inflammatory agents using the carrageenin‐induced edema model. One of them (compound 7b) showed important in vivo anti‐inflammatory effect (41%) similar to that of indomethacin (47%) used as the reference drug.
Proportion of prey consumed can be determined from faecal DNA using real‐time PCR
Authors: BOWLES ELLA , SCHULTE PATRICIA M. , TOLLIT DOMINIC J. , DEAGLE BRUCE E. , TRITES ANDREW W.
Published: January 2011

Reconstructing the diets of pinnipeds by visually identifying prey remains recovered in faecal samples is challenging because of differences in digestion and passage rates of hard parts. Analysing the soft‐matrix of faecal material using DNA‐based techniques is an alternative means to identify prey species consumed, but published techniques are largely nonquantitative, which limits their usefulness for some applications. We further developed and validated a real‐time PCR technique using species‐specific mitochondrial DNA primers to quantify the proportion of prey in the diets of Steller sea lions (Eumetopias jubatus), a pinniped species thought to be facing significant diet related challenges in the North Pacific. We first demonstrated that the proportions of prey tissue DNA in mixtures of DNA isolated from four prey species could be estimated within a margin of ∼12% of the percent in the mix. These prey species included herring Clupea palasii, eulachon Thaleichthyes pacificus, squid Loligo opalescens and rosethorn rockfish Sebastes helvomaculatus. We then applied real‐time PCR to DNA extracted from faecal samples obtained from Steller sea lions in captivity that were fed 11 different combinations of herring, eulachon, squid and Pacific ocean perch rockfish (Sebastes alutus), ranging from 7% to 75% contributions per meal (by wet weight). The difference between the average percentage estimated by real‐time PCR and the percentage of prey consumed was generally < 12% for all diets fed. Our findings indicate that real‐time PCR of faecal DNA can detect the approximate relative quantity of prey consumed for complex diets and prey species, including cephalopods and fish.
Reducing the backlash effect: Self‐monitoring and women's promotions
Authors: O’Neill Olivia A. , O’Reilly III Charles A.
Published: January 2011

Previous research shows that masculine (agentic) women suffer from a backlash effect in which they are sanctioned for violating the feminine gender role stereotype. We examine the impact of self‐monitoring on the promotion rates of MBA men and women over an 8‐year period following graduation. Results show that women who were more masculine as well as high on self‐monitoring received more promotions, suggesting that self‐monitoring is associated with an absence of backlash effects.
A dual action of saturated fatty acids on electrical activity in rat pancreatic β‐cells. Role of volume‐regulated anion channel and KATP channel currents
Authors: Best L. , Jarman E. , Brown P. D.
Published: January 2011

Non‐technical summary  Saturated free fatty acids (FFAs) have been shown to exert initial stimulatory actions on insulin‐producing cells, followed by a gradual impairment of insulin release. In this study we have investigated the effects of FFAs on the electrical properties of rat insulin‐secreting cells. We have demonstrated an initial stimulation followed by a gradual and prolonged inhibition of electrical activity by FFAs, actions that could account for the effects of FFAs on insulin release. We have also explored the underlying changes in ionic currents in insulin‐producing cells in response to FFAs. The results of the study could be relevant to the development of metabolic abnormalities brought about by high levels of FFAs in the circulation.
The Power of Women’s Tears
Authors: Stern Peter R.
Published: January 2011

Merely sniffing women's negative emotional tears reduces sexual arousal in men.
Gas patterns on plain abdominal radiographs: a pictorial review
Authors: Musson Rachel E , Bickle Ian , Vijay Ram K P
Published: January 2011

Abdominal radiographs are one of the most commonly performed radiological examinations and have an established role in the assessment of the acute abdomen. The main indication is for suspected bowel obstruction and in conjunction with an erect chest x-ray for suspected visceral perforation. Often, the pattern of gas points to a particular pathology, and accurate interpretation is important for prompt diagnosis. The diagnosis in most cases will be confirmed by further imaging studies such as ultrasound, contrast studies or, most commonly in contemporary practice, CT. This pictorial review summarises the various types of intraluminal and extraluminal gas patterns, illustrates some of the common clinical diagnoses made from plain films, describes some commonly encountered clinical problems with radiographs, and discusses the role of advanced imaging techniques.
Sterilisation of hybrid Galapagos tortoises (Geochelone nigra) for island restoration. Part 2: phallectomy of males under intrathecal anaesthesia with lidocaine
Authors: Rivera S. , Divers S. J. , Knafo S. E. , Martinez P. , Cayot L. J. , Tapia‐Aguilera W. , Flanagan J.
Published: January 2011

Lidocaine intrathecal anaesthesia was used to perform phallectomies in 15 hybrid Galapagos tortoises (Geochelone nigra) in a field setting as part of a conservation and ecosystem restoration project in the Galapagos Islands. The intrathecal injection was performed in the dorsal intercoccygeal region of the tail. Once the tail and hindlimbs were relaxed and the phallus was easily exteriorised, phallectomy was performed in a routine manner. All the animals recovered well from the procedure and were walking 30 to 60 minutes after surgery. No adverse effects were noted as a result of lidocaine intrathecal anaesthesia. One of the larger animals had evidence of haemorrhage from the surgical site 48 hours postoperatively. All tortoises continued to make full recoveries and were released on to the island of Pinta in May 2010.
Tectono-stratigraphic terranes and the metamorphic history of the northeastern part of the crystalline core of the North Cascades: evidence from the Twisp Valley Schist
Authors: Miller Robert B. , Whitney Donna L. , Geary Edward E.
Published: January 2011

The Twisp Valley Schist (TVS) is important for both the correlation of terranes in the Cascades crystalline core and for the determination of the metamorphic pressure–temperature–time history of the northeastern part of the core. The TVS is a chaotically mixed unit of mainly siliceous schist (metachert) with significant amounts of metabasite, calc-silicate rock, and marble, and minor ultramafite and metapsammite. Geochemical analyses of metabasites indicate that the TVS contains both ocean-island basalts (OIB) and mid-ocean-ridge basalts (MORB). The TVS is lithologically similar to the Napeequa unit of the Chelan Mountains terrane in the Cascades core and is broadly correlative with units outside of the core, including the Mississippian–Jurassic Bridge River – Hozameen terrane of the eastern Coast belt, and coeval OIB-bearing terranes in the Northwest Cascades thrust system. Much of the northeastern Cascades core thus consists of oceanic rocks that probably originally lay between the Insular and the Intermontane superterranes, or were part of the latter superterrane.The TVS experienced polyphase deformation and greenschist to middle amphibolite facies metamorphism during the interval from 90 Ma (and possibly earlier) to ca. 50 Ma. Paleocene (ca. 65–58 Ma) dynamothermal metamorphism is the best documented event and in part resulted from forcible emplacement of plutons and from broadly distributed deformation in the Ross Lake fault zone. Major crustal loading of the TVS is inferred from the replacement of andalusite by kyanite, the presence of garnets that record an increase in pressure of 1.5–3.0 kbar (1 kbar = 100 MPa) from cores to rims, and the deeper emplacement levels of younger plutons. Loading may record thrusting in the northeastern core that is bracketed between 88 and 65 Ma and is younger than previously recognized, major contractional deformation in the North Cascades.
Regional setting and kinematic features of the Needle Falls Shear Zone, Trans-Hudson Orogen
Authors: Stauffer Mel R. , Lewry John F.
Published: January 2011

Needle Falls Shear Zone is the southern part of a major northeast-trending ductile shear system within the Paleoproterozoic Trans-Hudson Orogen in Saskatchewan. Throughout its exposed length of ~400 km, the shear zone separates reworked Archean continental crust and infolded Paleoproterozoic supracrustals of the Cree Lake Zone, to the northwest, from mainly juvenile Paleoproterozoic arc terrains and granitoid plutons of the Reindeer Zone, to the southeast. It also defines the northwest margin of the ca. 1855 Ma Wathaman Batholith, which forms the main protolith to shear zone mylonites. Although not precisely dated, available age constraints suggest that the shear zone formed between ca. 1855 and 1800 Ma, toward the end of peak thermotectonism in this part of the orogen.In the Needle Falls study area, shear zone mylonites exhibit varied, sequentially developed, ductile to brittle fabric features, including C–S fabrics, winged porphyroclasts (especially delta type), small-scale compressional and extensional microfaults ranging from thin ductile shear zones to late brittle faults, early isoclinal and sheath folds, later asymmetric folds related to compressional microfaults, and variably rotated and (or) folded quartz veins. All ductile shear-sense indicators suggest dextral displacement, as do most later ductile–brittle transition and brittle features. In conjunction with a gently north–northeast-plunging extension lineation, such data indicate oblique east-side-up dextral movement across the shear zone. However, preexisting structures in country rock protoliths rotate into the shear zone in a sense contrary to that predicted by ideal dextral simple shear, a feature thought to reflect significant flattening across the shear zone. Other ductile to brittle fabric elements in the mylonites are consistent with general noncoaxial strain, rather than ideal simple shear. Amount of displacement cannot be measured but indirect estimates suggest approximately 40 ± 20 km.The Needle Falls Shear Zone is too small and has developed too late in regional tectonic history to be considered a crustal suture. Rather, it is interpreted as either a late-tectonic oblique collisional structure or as the result of counterclockwise oroclinal rotation of the southern part of the orogen.
The analysis of three-dimensional orientation data
Authors: Starkey John
Published: January 2011

For many observed orientation patterns of three-dimensional geological data no statistical tests are available that define the probability with which a measured sample represents the parent population. Consequently, there is no accepted definition of an appropriate sample size and patterns can only be compared qualitatively by visual inspection. Empirical solutions to these problems are proposed and applied to quartz c-axis orientation patterns. An estimate of the distribution of orientations in a parent population is provided by an orientation diagram prepared by contouring a measured sample represented on the surface of a sphere using a counting circle 100/n% of the area of the projected hemisphere, where n is the sample size. Contouring the sample as it is accumulated allows identification of the sample size beyond which there is no significant change in the measured pattern. Data from similar-sized samples of computer-simulated random patterns provide outside estimates of the likely differences between the measured sample and the parent population. Pairs of patterns are compared using the mean absolute difference between the matrices used to prepare the contoured diagrams. A measure of their similarity is provided by the magnitude of this difference as a function of the departure of the two patterns from randomness, as indicated by the amount of empty space present. Characterization of the traditionally recognized types of quartz c-axis orientation patterns, using the parameters of the orientation patterns or their normalized eigenvectors, is successful only with point maximum, partial girdle, girdle, and random orientation patterns.
Late Quaternary paleoceanography of deep and intermediate water masses off Gaspé Peninsula, Gulf of St. Lawrence: foraminiferal evidence
Authors: Rodrigues Cyril G. , Ceman James A. , Vilks Gustavs
Published: January 2011

Radiocarbon-dated benthonic foraminiferal zones in three cores provide new information on the evolution of the deep and intermediate water masses off Gaspé Peninsula. The deglacial phase in the deep Laurentian Channel began before 14 000 BP and was characterized by low-salinity (<20‰) or alternating low-salinity and saline (~35‰) water. This was followed by a cold saline phase, which ended ca. 13 500 BP, and a salinity minimum (30–33.5‰), which began ca. 12 100 BP. Between 8700 and 7900 BP, the temperature and salinity of the deep water mass increased, resulting in the modern deep water mass (temperature 4–6 °C, salinity 34.5–34.9‰) at the end of the Goldthwait Sea episode. The salinity of the deep water was apparently controlled by the meltwater flux from the ice front during the deglacial phase. After the deglacial phase the characteristics of the deep water mass were determined by the composition of offshore water entering the Laurentian Channel. Runoff from the Lake Agassiz – Great Lakes system does not appear to have mixed with the deep water of the Goldthwait Sea. The deglacial phase in Chaleur Trough, which is within the intermediate water mass, began before 12 200 BP. The temperature of the intermediate water mass has remained close to 0 °C after deglaciation; however, the salinity has increased from 25–30‰ at 12 200 BP to about 33.5‰ by 5900 BP.
Early Proterozoic (1.88–1.87 Ga) tholeiitic magmatism in the New Québec orogen
Authors: Skulski Thomas , Wares Robert P. , Smith Alan D.
Published: January 2011

The New Québec orogen contains two volcano-sedimentary sequences bounded by unconformities. Each sequence records a change from continental sedimentation and alkaline volcanism to marine sedimentation and tholeiitic volcanism. The first sequence records 2.17 Ga rifting and the development, by 2.14 Ga, of a passive margin along the eastern part of the Superior craton. The second sequence developed between 1.88 and 1.87 Ga in pull-apart basins that reflect precollisional dextral transtension along the continental margin. Second-sequence magmatism comprises (i) carbonatitic and lamprophyric intrusions and mildly alkaline mafic to felsic volcanic rocks; (ii) widespread intrusion of tholeiitic gabbro sills, and submarine extrusion of plagioclase glomeroporphyritic basalts and younger aphyric basalts and picrites; and (iii) late-stage, mafic to felsic volcanism and intrusion of carbonatites. Crustal thinning allowed primitive tholeiitic magmas to equilibrate at progressively lower pressures before more buoyant derivative liquids could erupt. Early primitive melts were trapped at the base of the crust and crystallized olivine and orthopyroxene with minor crustal contamination. Derivative melts, similar to transitional mid-ocean-ridge basalts, migrated upward into mid-crustal magma chambers where they became saturated in calcic plagioclase. Subsequent tapping of these magma chambers allowed plagioclase ultraphyric magmas to intrude the sedimentary pile and erupt on the sea floor. Prolonged lithospheric extension resulted in more voluminous mantle melting and eruption of picrites and basalts in the south. Primitive magmas in the north were trapped beneath thicker crust and crystallized wehrlite cumulates. Resulting basaltic melts intruded the volcano-sedimentary pile, or erupted as aphyric basalts.
The Deer Cove deposit, Baie Verte Peninsula, Newfoundland, a Paleozoic mesothermal lode-gold occurrence in the northern Appalachians
Authors: Patey Karen S. , Wilton Derek H. C.
Published: January 2011

The Siluro-Devonian Deer Cove deposit, Baie Verte Peninsula, Newfoundland, is hosted by volcanic cover rocks of the Point Rousse Complex ophiolite. Mineralization consists of quartz vein lodes with gold, pyrite, lesser chalcopyrite, and minor arsenopyrite. Gold occurs as relatively pure gold intergrown with pyrite, and as solitary grains within the quartz gangue. Host rocks include basalt and gabbro at greenschist-facies metamorphic grade. The volcanic rocks have a general calcalkaline affinity, with (anhydrous) SiO2, TiO2, MgO, Al2O3, and Zr contents of 34–62%, 0.36–0.9%, 2.8–9%, 13.4–18.5%, and 28–48 ppm, respectively; Mg # ranges from 37 to 61. The host basaltic rocks were the products of island-arc or back-arc volcanism. Well-developed alteration haloes surround the quartz veins; the alteration grades from quartz–chlorite–carbonate in the veins, through sericitic wall rock, into propylitic (chlorite–epidote–carbonate–leucoxene) host rock. Trace-element geochemistry indicates that the ore fluids had large-ion lithophile element relationships similar to average crustal values. δ13C and δ18O values of carbonate separates range from −7 to −8‰ and 10 to 12‰, respectively. On the basis of geochemical, alteration, and isotopic data, the Deer Cove deposit should be classified as a typical mesothermal lode-gold occurrence. The veins apparently formed from mesothermal fluids with average crustal compositions that flowed along brittle fracture systems within the cover sequence during Siluro-Devonian Acadian deformation. As such the veins were unrelated to either sea-floor processes or Taconic ophiolite obduction. The vein systems apparently formed during transpressive tectonism which followed ocean closure and ophiolite obduction.
Toe erosion of glacial till bluffs: Lake Erie south shore
Authors: Amin Shahalam M. N. , Davidson-Arnott Robin G. D.
Published: January 2011

Toe erosion and rates of recession of the toe were measured at four sites along a 3.5 km long stretch of shoreline on the south shore of Lake Erie from April to December 1986. The shoreline consists of bluffs ranging from 5 to 12 m in height and developed in overconsolidated till. Toe erosion was measured at peg lines consisting of pins driven horizontally into the face of the bluff at 0.25 m intervals to a height of 1.75 m above the beach, and steel rods driven vertically into the beach with a spacing of 1.5 m. At each site three lines were established and monitored at 1–2 week intervals. Because of record high lake levels, beaches in front of the bluffs were generally <5 m wide, and some erosion was measured on all but three occasions. Recession of the toe during any measurement period was generally 2–6 cm, with the maximum recorded being about 12 cm. Wave action during high-magnitude storms resulted in erosion occurring much higher up the bluff face than for low-magnitude events, but the actual recession of the toe was not substantially greater. A multiple regression model shows that there is a significant relationship between toe recession and several variables that indirectly control wave energy at the bluff toe. However, factors such as beach width and thickness of beach sediment did not have a significant influence on recession rates in this study, likely because the high lake levels resulted in very narrow beaches at all four sites throughout the study period.
Tetrapod remains from the late Mississippian Pomquet Formation near Grand Étang, Nova Scotia
Authors: Holmes Robert , Godfrey Stephen , Baird Donald
Published: January 2011

Isolated amphibian bones are preserved in freshwater sediments of the Namurian A Pomquet Formation near Grand Étang, Nova Scotia. This assemblage resembles other late Mississippian lakebed or estuarine faunas in that most of the remains can be confidently attributed to one or more taxa of embolomere (order Anthracosauria) or to the order Colosteoidea, although they are indeterminate at the level of genus and species. However, a number of tetrapod elements of uncertain affinities suggests a much more diverse fauna.
The hydrologic regime of Mackenzie River and connection of "no-closure" lakes to distributary channels in the Mackenzie Delta, Northwest Territories
Authors: Burn C. R.
Published: January 2011

Mackenzie Delta lakes have been classified by the seasonal duration of their connection to Mackenzie River. "No-closure" lakes are determined on the basis of minimum summer water level. Such lakes may become disconnected from the Mackenzie in autumn or winter, as water level falls or if the sills between lakes and distributary channels are frozen through and so sealed. Water level in the central delta rises continuously after late November–early December, at first because discharge into the delta increases once the Mackenzie drainage basin has frozen over, and then as sea and channel ice thickens in the outer delta, impounding discharge. Since 1973 this seasonal increase in stage from its minimum in early December to the level on 1 April has been between 29 and 95 cm. Between 1987 and 1994, the rise in stage near Inuvik has been slightly greater than increases in lake-ice thickness (30–68 cm). Channels and lakes that are connected to the Mackenzie discharge system in December may remain connected throughout winter. A critical sill elevation for connection of such lakes to the river system is the minimum stage minus mid-December ice thickness. Recently, these elevations have been from 1.0 to 1.6 m lower than late summer water levels. Lakes with sill elevations still lower may remain connected to the Mackenzie throughout the year. In 1993-1994, only 3 of 16 "no-closure" lakes surveyed near Inuvik remained open to the Mackenzie discharge throughout winter, representing 2% of the lakes in this portion of the delta.
Chronology of Avalonian events on Presqu'île du Cap Miquelon (Le Cap), Saint-Pierre et Miquelon (France)
Authors: Dunning G.R. , Lepvrier C. , O'brien S.J. , Colman-Sadd S.P. , Maluski H.
Published: January 2011

U/Pb geochronology and field studies on Presqu'île du Cap Miquelon demonstrate that amphibolite-grade metamorphism, ductile deformation, and subsequent plutonism in this part of the Appalachian Avalon Zone are of Proterozoic age. Clear, crosscutting relationships between a dated granite dyke (part of the Cap Blanc granite) and foliated, amphibolite-grade metasedimentary and metaigneous rocks provide a younger age limit of [Formula: see text] Ma for tectonism. Proterozoic titanite and hornblende ages indicate that no significant younger thermal overprint occurred such as those recorded in nearby southern Newfoundland. Deformation and metamorphism of the country rocks and intrusion of the Cap Blanc granite are at least 30 Ma older than the onset of deposition of the youngest Proterozoic volcano-sedimentary successions in adjacent insular Newfoundland. Possible equivalents of these younger sequences occur near Cap Blanc, and contain what may be interpreted as clasts of granite, dated at 620 ± 3 Ma. The Miquelon metamorphic sequence is unique with respect to the southern Newfoundland Appalachians in representing a significant area of Proterozoic migmatite, not observably affected by tectonothermal events after 580 Ma.
Dégradation et lessivage des hydrocarbures de la formation ordovicienne de Thumb Mountain encaissant le gîte Zn–Pb de Polaris (Territoires du Nord-Ouest, Canada)
Authors: Disnar J.R. , Héroux Y.
Published: January 2011

Carbonate rocks of the Ordovician Thumb Mountain Formation, host to the Zn–Pb Polaris deposit, contain hydrocarbons that show types of alteration classically attributed to biodegradation and water washing. The hydrocarbons of the upper part of this formation and of the overlying Irene Bay Formation indicate alterations due to water washing only. The hydrocarbons of the impermeable shales of the overlying Cape Phillips Formation display indices of only higher thermal maturity than the underlying units. Contrary to classical concepts of hydrocarbon biodegradation, n-alkanes, cyclohexylalkanes, even isoprenoids and perhaps also steranes seem to have been degraded simultaneously and not successively in this sequence. This alteration process is mainly responsible for a log-linear decrease of the amounts of n-alkanes and cyclohexylalkanes with increasing depth. The severe and uniform alteration of aromatic hydrocarbons throughout the interval, which is opposite to the progressive alteration of associated n-alkanes, can be attributed solely to water washing. This conclusion necessitates a reconsideration of previous interpretations attributing the loss of short-side chain substituted polyaromatic compounds to microbial activity. Hopanes, tri-and tetra–cyclic terpanes as well as aromatic steroids and hopanoids seem to have been unaffected by the alteration phenomena. The increase in the degree of alteration of the hydrocarbons with increasing depth implies that the responsible migrating fluid circulated per ascensum.