bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of Sexual Functioning and Quality of Partnership in Patients in Cardiovascular Rehabilitation—A Gender Perspective
Authors: Günzler Cindy , Kriston Levente , Harms Anja , Berner Michael M.
Published: October 2008

Introduction

In the general population, studies indicate a strong association between sexual dysfunction and partnership quality. Despite a high prevalence of sexual problems in patients with cardiovascular diseases, this association has not yet been examined in this sample.

Aim

The central task of this paper is to determine the association between sexual dysfunction and quality of partnership under a gender-specific view.

Methods

A written survey was handed out to all newly admitted patients in five participating inpatient rehabilitation centers for cardiovascular diseases in Germany. The survey included a gender-specific questionnaire to assess sexual functioning (International Index of Erectile Function for men, and Female Sexual Function Index for women), and a Partnership Questionnaire.

Main Outcome Measures

Correlations were calculated between sexual function and relationship satisfaction, and differences between groups (cardiovascular diseased men and women with and without sexual problems) were tested using covariance analyses.

Results

Overall, 44.3% of 98 female participants and 52.7% of 395 male participants stated to have at least one sexual problem. Patients with sexual problems showed significantly more quarrelling (P = 0.001), significantly less tenderness (P < 0.001), communication (P < 0.001), as well as significantly lower overall quality of partnership (P < 0.001), compared with cardiac men and women without sexual problems. Suffering from a sexual problem impaired partnership quality for women to a significantly greater extent than for men.

Conclusions

Possible shortcomings of our study are selection bias, i.e., it is unknown whether all newly admitted patients received the questionnaire by their physician, as well as an overall low response rate, probably because of the private character of questions. This study suggests for the first time that men and women who suffer from cardiovascular diseases and sexual problems show a significantly decreased partnership satisfaction compared with those without sexual dysfunction. Further longitudinal studies might confirm the causal nature of found correlations.
The Effects of Treating Male Hypogonadism on Couples’ Sexual Desire and Function
Authors: Conaglen John V. , Conaglen Helen M.
Published: October 2008

Introduction

Hypogonadism is a common endocrine condition characterized by low levels of testosterone (T) and marked by numerous symptoms, one of which is low sexual desire. Studies comparing T delivery systems have suggested that hypogonadal men’s partners may be at risk from exposure to T gels. Little other mention is found of the impact of hypogonadism and its treatment on a man’s partner and the couple’s sexual function.

Aim

To assess sexual desire and sexual function in hypogonadal men and their woman partners before and after treatment with T replacement therapy.

Methods

Twenty-one hypogonadal men and 18 partners were recruited from a tertiary endocrine clinic, and were compared with a control group of 20 eugonadal age-matched men and their partners. All men had baseline blood tests to confirm their status as hypogonadal or eugonadal, and hypogonadal men repeated tests at 3-month intervals. All participants completed the Sexual Desire Inventory (SDI) and sexual function questionnaires at baseline and at 3-month intervals until the hypogonadal men attained normal T levels.

Main Outcome Measures

Pre- and post-treatment SDI and sexual function questionnaires were compared once T normalization was achieved. Between- and within-group comparisons were carried out.

Results

Pretreatment hypogonadal men recorded lower levels of sexual desire and function than controls, but significantly improved once hypogonadism was corrected. Eugonadal controls recorded no significant changes in either sexual desire or function during the study. Partners of the hypogonadal men reported no changes on the SDI, but significant improvements in sexual function as their partners recovered.

Conclusion

SDI and sexual function measures reflect sexual changes that accompany rising serum T levels during correction of male hypogonadism. Women partners reported more satisfaction, less pain, and improved sexual function following the men’s treatment. Treatments affecting one partner potentially have important effects on the other.
Recommendations for Improving Sexual Health Curricula in Medical Schools: Results from a Two-Arm Study Collecting Data from Patients and Medical Students
Authors: Wittenberg Alyssa , Gerber Judith
Published: October 2008

Introduction

Although patients commonly have sexual concerns, providers often feel uncomfortable or inadequately trained to address these concerns.

Aims

The first aim of this study was to determine how patients most prefer to receive sexual health information and how provider characteristics affect patient comfort. The second aim was to look at the sexual health curriculum at one medical school and determine its effectiveness. The third aim was to incorporate student and patient responses to create guidelines for more effective sexual health curricula.

Methods

Undergraduate and graduate students served as the study sample in arm one (N = 501). Medical students in their third and fourth year served as the study sample in arm two (N = 125). Participants were surveyed anonymously using standard forms.

Main Outcome Measures

A cross-sectional descriptive analysis was generated from all collected data using SPSS software.

Results

Patients most prefer to receive sexual health information from their provider who initiates the conversation (45.1%) and least prefer information from the Internet (25.4%). Patients are most comfortable with providers who are “knowledgeable about sexual concerns” (74.5%) and “seem comfortable addressing sexual concerns” (68.3%). The majority of medical students (75.2%) feels that taking a sexual history will be an important part of their future careers, yet only 57.6% feel adequately trained to do so. Furthermore, 68.8% feel that addressing and treating sexual concerns will be an important part of their future careers, and only 37.6% feel adequately trained to do so.

Conclusion

Patients prefer to receive sexual health information from knowledgeable providers who are comfortable with sexual health. Current medical students see value in sexual health curricula and feel this training will be important to their future careers, however, they feel inadequately trained. Sexual health curricula must be modified for increased effectiveness with additional lectures and opportunity for students to practice these skills.
Relative Roles of Disturbance and Propagule Pressure on the Invasion of Humid Tropical Forest by Cordia alliodora (Boraginaceae) in Tanzania
Authors: Edward Ezekiel , Munishi Pantaleo K. T. , Hulme Philip E.
Published: October 2008

Current understanding of the vulnerability of tropical forests to plant invasion is limited but is widely believed to increase where forests: (1) suffer marked natural or man‐made disturbance; and/or (2) are exposed to high propagule pressure of alien species. This study aimed, for the first time, to address the importance of propagule pressure and disturbance by examining the spread of an introduced tree, Cordia alliodora, from a single plantation into a surrounding mosaic of humid forest in the East Usambara Mountains, Tanzania. By assessing vulnerability to invasion along transects radiating from the plantation, the effects of distance (measure of propagule pressure), and disturbance could be discerned. For all life stages, distance from source population was the strongest correlate of density. A marked influence of disturbance was only evident for C. alliodora seedlings. Spatial variation in the densities of later life stages may be a function of past disturbances, less easy to assess from current surveys, especially following the marked self‐thinning between seedling and adult densities. Nevertheless, the evidence suggests that propagule pressure is a more important determinant of Cordia density than disturbance. If this is true for other alien tree species in tropical forests, controlling for introduction effort is essential to assess the drivers of plant invasion. Given an annual population growth rate of ca 3.5 percent, equivalent to the population doubling every 20 yr, C. alliodora poses a significant threat to the East Usambaras as well as other humid forests where it is promoted for agroforestry.
Barriers to health care and health‐seeking behaviors faced by Black men
Authors: Cheatham Cessaly T. , Barksdale Debra J. , Rodgers Shielda G.
Published: October 2008

Purpose: To describe unique barriers to health care and health‐seeking behaviors faced by Black men and to make recommendations to healthcare providers for improving healthcare access for Black men.

Data sources: A PubMed search for research articles published after 1999 was conducted.

Conclusions: The articles selected for this state of the science clinical paper addressed barriers to access faced by Black men and/or management strategies used to mitigate barriers and improve access. The barriers identified include socioeconomic status, masculinity, racism, lack of awareness of the need for primary care, religious beliefs, and peer influences. As singular entities, these may not appear unique, but when viewed collectively, they represent an overwhelming constellation of obstacles for Black men.

Implications for practice: Individual, community, state, and national level recommendations for nurse practitioner actions to improve healthcare access for Black men include public service announcements, radio commercials, and billboards aimed at raising awareness of healthcare issues in the Black community, provision of preventive services through health fairs, and development of positive provider–patient relationships.
The importance of managing cardiovascular risk in the treatment of hypertension: The role of ACE inhibitors and ARBs
Authors: Pierson Charon A. , Epstein Benjamin J. , Roberts Mary Ellen
Published: October 2008

Disclosure: This work was supported by Boehringer Ingelheim Pharmaceuticals, Inc. Each participant received an honorarium from Boehringer Ingelheim Pharmaceuticals, Inc. for time and effort involved in participating in the discussion and reviewing the transcript for accuracy of content and readability prior to publication. The participants retained full control of the discussion and the resulting content of this article. The content was not reviewed or changed by Boehringer Ingelheim Pharmaceuticals, Inc. in any way.
Intra‐carotid hyperosmotic stimulation increases Fos staining in forebrain organum vasculosum laminae terminalis neurones that project to the hypothalamic paraventricular nucleus
Authors: Shi Peng , Martinez Michelle A. , Calderon Alfredo S. , Chen Qinghui , Cunningham J. Thomas , Toney Glenn M.
Published: October 2008

Body fluid hyperosmolality has long been known to elicit homeostatic responses that range from drinking to inhibition of salt appetite to release of neurohypohyseal hormones (i.e. vasopressin and oxytocin). More recently, it has been recognized that hyperosmolality is capable of also provoking a significant increase of sympathetic nerve activity (SNA). It has been reported that neurones in the forebrain organum vasculosum laminae terminalis (OVLT) and hypothalamic paraventricular nucleus (PVN) each contribute significantly to this response. Here we sought to determine if sympathoexcitatory levels of hyperosmolality activate specifically those OVLT neurones that form a monosynaptic pathway to the PVN. First, we established in anaesthetized rats that graded concentrations of hypertonic NaCl (1.5 and 3.0 osmol kg−1) elicit graded increases of renal SNA (RSNA) when infused at a rate of 0.1 ml min−1 through an internal carotid artery (ICA) – the major vascular supply of the forebrain. Next, infusions were performed in conscious rats in which OVLT neurones projecting to the PVN (OVLT‐PVN) were retrogradely labelled with cholera toxin subunit B (CTB). Immunostaining of the immediate early gene product Fos and CTB was performed to quantify osmotic activation of OVLT‐PVN neurones. ICA infusions of hypertonic NaCl and mannitol each significantly (P < 0.01–0.001) increased the number of Fos immunoreactive (Fos‐ir) neuronal nuclei in the dorsal cap (DC) and lateral margins (LM) of OVLT. In the LM, infusions of 1.5 and 3.0 osmol kg−1 NaCl produced similar increases in the number of Fos‐ir neurones. In the DC, these infusions produced graded increases in Fos expression. Among OVLT neurones with axons projecting directly to the PVN (i.e. CTB‐ir), graded hypertonic NaCl infusions again produced graded increases in Fos expression and this was observed in both the DC and LM. Although the DC and LM contained a similar number of OVLT‐PVN neurones, the proportion of such neurones that expressed Fos‐ir in responses to ICA hypertonic NaCl infusions was greater in the DC (P < 0.001). These findings support the conclusion that PVN‐projecting neurones in the DC and LM of OVLT could participate in behavioural, neuroendocrine, and sympathetic nervous system responses to body fluid hyperosmolality.
A Better Way to Choose?
Authors: McLean Iain
Published: October 2008

Mathematics and Democracy
. Designing Better Voting and Fair-Division Procedures.
By Steven J. Brams
. Princeton University Press, Princeton, NJ, 2008. 389 pp. Paper, $27.95, £16.95. ISBN 9780691133218.

Brams uses social choice and game theory to argue for procedures that allow voters to better express their preferences and disputants to divide goods more fairly.
Elective Inequality
Authors: Grafstein Robert
Published: October 2008

Unequal Democracy
. The Political Economy of the New Gilded Age.
By Larry M. Bartels
. Russell Sage Foundation, New York, and Princeton University Press, Princeton, NJ, 2008. 341 pp. $29.95, £17.95. ISBN 9780691136639.

Bartels explores the political causes and consequences of the growing economic inequality in the United States.
Gastric emptying in preterm infants.
Authors: Ewer A K , Durbin G M , Morgan M E , Booth I W
Published: October 2008

An ultrasonic technique was used to compare gastric emptying after a feed of expressed breast milk and formula milk in a blind, cross over study of preterm infants. Fourteen infants (median gestational age 33 weeks) were studied on 46 occasions. Each infant received a nasogastric feed of either expressed breast milk or formula milk, and the alternative at the next feed. Real time ultrasound images of the gastric antrum were obtained and measurements of antral cross sectional area (ACSA) were made before the feed and then sequentially after its completion until the ACSA returned to its prefeed value. The half emptying time (50% delta ACSA) was calculated as the time taken for the ACSA to decrease to half the maximum increment. On average, expressed breast milk emptied twice as fast as formula milk: mean 50% delta ACSA expressed breast milk 36 minutes; formula milk 72 minutes. The technique was reproducible and there was no significant difference between the emptying rates of feeds of the same type for an individual infant. These data show that breast milk has a major effect on gastric emptying, which may have important implications for preterm infants who have a feed intolerance due to delayed gastric emptying.
Factors affecting survival and outcome at 3 years in extremely preterm infants.
Authors: Cooke R W
Published: October 2008

A total of 823 infants born at 28 weeks' gestation or less were admitted to a regional referral unit between 1980 and 1989. Four hundred and sixty five (56.5%) survived to be discharged home. Twenty one subsequently died and two were lost to follow up. Four hundred and forty two (53.7%) were assessed for disabilities at the age of 3 years. Eighty four (19%) had major disabilities, of which 40 (9%) were severe. A further 39 (9%) had lesser disabilities. Three hundred and nineteen (63%) survivors appeared to be functioning normally. Logistic regression showed the likelihood of survival to be independently related to gestational age, birthweight ratio, and more recent year of birth, and inversely related to male sex and ultrasound evidence of cerebral haemorrhage or infarction. The likelihood of later disability in survivors was only independently related to cerebral ultrasound appearances.
First thoracic vertebral body as reference for endotracheal tube placement.
Authors: Blayney M P , Logan D R
Published: October 2008

After intubation in newborn infants, the placement of the endotracheal tube in the trachea must be checked by a chest radiograph. The most commonly used reference point for placement is the medial ends of the clavicles. The position of the clavicles may be variable. The present study was carried out to determine whether the body of the first thoracic vertebra should be used instead of the clavicles because its position on chest radiographs is more constant. Seventy eight radiographs obtained from 35 neonates were examined prospectively. The carina was situated between T3 and T5, most commonly at T3-4 or T4 (85%). The position of the clavicles varied markedly from patient to patient and within the same patient on different days, and this variation was significantly higher than that of the carina. On 65 (83%) examinations the clavicles lay above the first thoracic vertebra. It is recommended that, for accurate placement within the trachea, the tip of the endotracheal tube should be placed at the level of the body of the first thoracic vertebra; this could be used as the sole reference point on chest radiographs obtained in the neonatal period.
High plasma vitamin C concentrations at birth associated with low antioxidant status and poor outcome in premature infants.
Authors: Silvers K M , Gibson A T , Powers H J
Published: October 2008

Concentrations of circulating antioxidants may be important in the aetiology of disease in premature infants. Blood samples were taken from 49 premature infants within two hours of birth. Plasma ascorbic acid, caeruloplasmin, and the ability of plasma to prevent lipid peroxidation in vitro were measured. Plasma ascorbic acid concentrations at birth ranged from 26.3 to 185.4 mumol/l. Plasma antioxidant activity at birth (microliter plasma required to inhibit lipid peroxidation) showed a strong negative correlation with plasma ascorbic acid and the plasma ascorbic acid to caeruloplasmin ratio. After correcting for gestational age and birth weight, plasma antioxidant activity at birth remained a significant predictor of mortality. Such plasma antioxidant activity is partly determined by the ferroxidase activity of caeruloplasmin. This may be modulated by high concentrations of ascorbic acid which may inhibit the antioxidant activity of plasma and thereby influence outcome.
Dose conversion from aminophylline to theophylline in preterm infants.
Authors: Reese J , Prentice G , Yu V Y
Published: October 2008

Twenty two preterm infants were prospectively evaluated to assess the need for dose adjustment when converting enteral and parenteral routes of methylxanthine administration. Serum theophylline concentrations remained unchanged in 18 infants after conversion from intravenous aminophylline to theophylline by mouth without dose reduction, as is currently recommended. Intravenous aminophylline and theophylline by mouth may therefore be prescribed at equivalent doses, with a possible reduction in drug errors, and improved stability of serum concentrations.
Effects of polycythaemia and haemodilution on circulation in neonates.
Authors: Mandelbaum V H , Guajardo C D , Nelle M , Linderkamp O
Published: October 2008

Haemodilution in nine neonates resulted in significant mean (SEM) decrease of packed cell volume (0.67 (0.01) to 0.55 (0.01)) and increases in cardiac output (250 (16) to 308 (25) ml/min/kg) and blood flow velocities of the internal carotid artery and the coeliac artery (+20%). However, red cell flows in the aorta, carotid and coeliac arteries did not change during haemodilution, thereby indicating that haemodilution did not improve oxygen transport.
Trisomy 22 and intersex.
Authors: Nicholl R M , Grimsley L , Butler L , Palmer R W , Rees H C , Savage M O , Costeloe K
Published: October 2008

Complete trisomy 22, with or without mosaicism, has been reported as a distinct syndrome. In this report an infant is described who was externally male but with female rudimentary internal organs and whose karyotype was 47,XX+22.
Empirical developments in retraction
Authors: Redman B K , Yarandi H N , Merz J F
Published: October 2008

This study provides current data on key questions about retraction of scientific articles. Findings confirm that the rate of retractions remains low but is increasing. The most commonly cited reason for retraction was research error or inability to reproduce results; the rate from research misconduct is an underestimate, since some retractions necessitated by research misconduct were reported as being due to inability to reproduce. Retraction by parties other than authors is increasing, especially for research misconduct. Although retractions are on average occurring sooner after publication than in the past, citation analysis shows that they are not being recognised by subsequent users of the work. Findings suggest that editors and institutional officials are taking more responsibility for correcting the scientific record but that reasons published in the retraction notice are not always reliable. More aggressive means of notification to the scientific community appear to be necessary.
Socioeconomic differences in smoking trends among pregnant women at first antenatal visit in Sweden 1982–2001: increasing importance of educational level for the total burden of smoking
Authors: Moussa K , Östergren P O , Grahn M , Kunst A E , Eek F , Essén B
Published: October 2008

Background:

There was a decrease in smoking during early pregnancy in Swedish women between 1982 and 2001. We sought to determine whether there was a parallel decrease in socioeconomic inequality in smoking.

Methods:

Registry data indicating educational level and smoking status at first antenatal visit in all 2 022 469 pregnancies in Sweden 1982–2001 were analysed. Prevalence differences, odds ratios based on prevalences and total attributable fractions were compared for five-year intervals.

Results:

The prevalence differences of smoking showed a greater decrease at the lowest and middle educational level compared with the highest educational level (14.5%, 15.7% and 10.2%, respectively) indicating reduced inequality in absolute terms. However, odds ratios regarding low educational attainment versus high, increased from 5.6 to 14.2, signifying increased inequality in relative terms. Moreover, the total attributable fraction of low and intermediate educational level regarding smoking at first antenatal visit increased from 61% to 76% during the period studied.

Conclusions:

Smoking at first antenatal visit in Sweden between 1982 to 2001 decreased in a way that conclusions regarding trends in inequalities in smoking at first antenatal visit depend on the type of measure applied. However, using the measure of total attributable fraction, which takes into consideration the impact of the exposure on the individual as well as the effect of the varying size of the group of exposed, the growing importance of educational level for the behaviour in the population was demonstrated.
The Mid-Atlantic Ridge near 45 °N. VI. Remanent intensity, susceptibility, and iron content of dredged samples
Authors: Irving E. , Robertson W. A. , Aumento F.
Published: October 2008

Results from 27 dredge hauls (75 samples) spaced from 150 km west to 70 km east of the Median Valley of the Mid-Atlantic Ridge at about 45 °N are reported. Basalt is the most common rock type. The basalts have a mean remanent intensity of 92 × 10−4 and a mean susceptibility of 0.9 × 10−4 cgs cm−3. The remanence varies with distance from the axis, samples from the Median Valley (mean 574 × 10−4) being ten times more magnetic than samples at a greater distance. Most of this decrease of intensity occurs within a few kilometers (less than 6 km) of the central axis and within the zone of active volcanism. It is suggested that this dramatic drop in intensity is caused by viscous decay enhanced by thermal cycling or by chemical change in the narrow volcanic axial zone.Certain other properties of the basalts vary with distance; the blocking temperatures and stability (versus a.f. demagnetization) increase, and the ratio FeO/Fe2O3 decreases with distance. These changes are most marked at the inner slopes of the Crestal Mountains not within the narrow axial zone, and it is possible that they reflect sampling bias, the samples from the Median Valley being from flow margins, whereas the collections from the flanks contain material from the centers of flows.Non-basaltic rocks include serpentinized peridotite, greenstone, gabbro, and diabase. Serpentinized peridotite samples are strongly magnetic and have a mean intensity of 23 × 10−4 cgs cm−3. Greenstones, gabbros, and diabases are weakly magnetized, with mean intensities of about 10−4. Moreover, basalt showing partial alteration to greenstone has intermediate intensities showing that such a metamorphic process effectively demagnetizes a rock. This result is more consistent with the idea that Layer 3 is composed predominantly of gabbro and metamorphosed basalt rather than of serpentinized peridotite. The remanence and susceptibilities of 18 "erratic" samples, which are thought from other evidence to have been deposited by Pleistocene icebergs, have a wide and irregular spread.
Post-glacial uplift and substrate age at Cape Henrietta Maria, southeastern Hudson Bay, Canada
Authors: Webber P. J. , Richardson J. W. , Andrews J. T.
Published: October 2008

As a basis for future ecological and biogeographical studies, the post-glacial emergence history of Cape Henrietta Maria was required. This was obtained by fitting a post-glacial emergence curve to a number of radiocarbon dated marine strandlines of known elevation. Analysis shows that the elevation of lower samples is critical for a reasonable prediction of higher relative sea levels. This emergence curve suggests that during the last 1000 y uplift has been about 1.2 m per century. Extrapolation to likely dates of deglaciation (8000−7000 BP) indicates a maximum marine inundation of > 300 m. The current rate of uplift, and the hypothetical elevation of the marine limit are the highest estimations to date for eastern and arctic Canada and support the hypothesis that a center of uplift and ice-loading is situated in southeastern Hudson Bay and northern James Bay. The derived emergence curve was used to construct an isochrone map of Polar Bear Park, in eastern northern Ontario. This map provides the basis for future biological studies of community migration and succession and demonstrates that the uplift curve is a useful chronological tool.
The Odd-twins magnetic anomaly and its possible relationship to the Humber Arm Klippe of Western Newfoundland, Canada
Authors: Ruffman Alan , Woodside John
Published: October 2008

A distinctive twin-peaked magnetic anomaly known as Odd-twins magnetic anomaly has been traced for a distance of 65 km parallel to the coast of western Newfoundland about 10 km offshore. The magnetic anomaly is associated with a bathymetric high in some areas. It is interpreted as having been produced by two parallel basic dikes (or sills) dipping 30–40° W. Such dikes would be near the base of the Long Point Formation and may delineate the western boundary of the Humber Arm Klippe.
Rb/Sr isochrons for some Precambrian rocks in the Hanson Lake area, Saskatchewan
Authors: Coleman L. C.
Published: October 2008

Rb–Sr whole rock analyses of rocks from the Hanson Lake area; Saskatchewan, combined with geological evidence suggest that there were three thermal events in that region during Precambrian time. During Archean time, a period of volcanism about 2520 m.y. ago was followed by a period of granite intrusion about 2445 m.y. ago. During Aphebian time, the rocks of the area were intruded by pegmatites about 1800 m.y. ago. If the analytical data alone are considered, the two earlier events should be considered as one that took place about 2425 m.y. ago.
Crystal growth and nucleation in two large diabase dikes
Authors: Gray N. H.
Published: October 2008

The total number of nuclei, Z, of a single phase formed in a unit volume of a crystallizing magma at the distance y from the contact of a semi-infinite intrusion is[Formula: see text]where n is a numerical constant determined by growth controlling process during the nucleation period and the value of m in the expression assumed for the nucleation rate, J[Formula: see text]The observed variation of Z for clinopyroxene and plagioclase from the contact towards the center of two large dikes appears to follow this relation. In the 106 m wide Kigaviarluk olivine tholeiite dike the value of n is significantly greater for the clinopyroxene (−2.2) than the plagioclase (−0.84). In the 60 m Grenville dike, a quartz tholeiite, the n value (−1.5) is the same for both minerals. The growth-controlling mechanisms of plagioclase and clinopyroxene appears to be sensitive to the bulk composition of the magma from which it is crystallizing.
Metamorphic framework and plutonic styles in the Prince Rupert region of the Central Coast Mountains, British Columbia
Authors: Hutchison W. W.
Published: October 2008

The metamorphic framework in Prince Rupert – Skeena region of the Coast Mountains of British Columbia comprises schist, gneiss, and migmatite displaying progressive regional metamorphism that overlaps the Barrovian and Idahoan Facies Series. Although part of the circum-Pacific metamorphic zone, the Coast Mountain metamorphic belt is apparently not paired. Plutonic rocks, which were probably an integral part of the early metamorphic framework, have apparently been mobilized during metamorphism and continued to move out of their original environment while metamorphism waned, some even deforming the pre-existing fabric.Within the framework, four main plutonic styles have been recognized:1) Autochthonous, migmatitic, plutonic complexes.2) Para-autochthonous, steep-walled (tadpole) plutons.3) Para-autochthonous, tongue-shaped, recumbent plutons.4) Allochthonous, intrusive plutons.Quartz diorite and granodiorite are the most common plutonic rocks. Diorite and quartz monzonite are less common: gabbro and especially granite are rare.In the course of moving from the sites of generation to the zones of emplacement, the plutonic rock became:1) more homogeneous.2) less migmatitic and impoverished in inclusions.3) less foliated.4) more acidic, more biotite-rich.5) a rock containing plagioclase of lower average anorthite content and more complex oscillatory zoned crystals.The complex oscillatory zoning appears in a gross way to reflect the variable history accompanying (pulsative ?) movement during crystallization.Time of emplacement of most of the plutonic rock is not known. The potassium–argon age dates (between 53° N and 55° N) display a consistent pattern, with a westerly zone yielding the oldest dates (84 to 140 m.y.), a median zone, intermediate dates (64 to 79 m.y.) and the eastern zone, youngest dates (chiefly 40 to 50 m.y.). These dates may reflect sequential emplacement from west to east but some evidence also suggests that they may reflect sequential uplift and unroofing from west to east.
The finite-amplitude instability in the folding of layered rocks
Authors: Chapple William M.
Published: October 2008

Examination and comparison of several computational studies of finite-amplitude single-layer folding bring to light an important unifying concept, that of the finite-amplitude instability. If the fold-causing stresses are constant throughout the development of a fold, the overall shortening strain-rate due to the folding will first show a marked increase with increasing fold amplitude and then decrease as the fold becomes tightly appressed; on the other hand, if the shortening strain-rate is held constant, the stresses necessary to maintain the constant shortening rate will decrease and then increase again. Considering the layer-in-medium system as a whole, this instability results in a bulk-effective viscosity with respect to layer-parallel compression, which is first high, then decreases to a minimum, and then rises again, These changes in bulk-effective viscosity are large, nearly two orders of magnitude.Effects of the finite-amplitude instability on the internal stresses within the layer and surrounding medium are as follows. First, there will probably be an early, low-amplitude stage with high layer-parallel stresses within the competent layer. The major development of deformation fabrics may occur during (his early stage. Second, development of plastic yield in the crestal region of the fold is strongly controlled by the details of external load pattern and therefore by the mechanism causing the folding. Third, the increase in effective bulk viscosity of the layer-in-medium system corresponds to a major rearrangement of the deformation patterns in both the medium and the layer.Consideration of décollement folding and multi-layer folding suggests that the concept of finite-amplitude instability may be applicable, at least qualitatively, to these more common fold types. If this is true, then the concept is important in considering more general geologic questions such as the dating of an orogenic episode by angular unconformity.
Seismic magnitudes of high-yield underground explosions
Authors: Basham P. W.
Published: October 2008

The seismic magnitude of the October 2, 1969 high-yield underground explosion (Milrow) in the Aleutian Islands, when compared to the magnitude of the smaller 1965 Long Shot explosion, suggests that in the yield range near 1 megaton the yield exponent in the amplitude-yield relationship is significantly less than the value of unity which applies for yields less than 100 kilotons. The lower exponent is shown to apply equally well to Nevada Test Site high-yield explosions. A general Aleutian site effect is observed to produce seismic magnitudes for Aleutian explosions that are about m0.3 larger than those of similar-yield explosions at the Nevada Test Site.
Recent crustal movements on the Labrador Shelf
Authors: Grant A. C.
Published: October 2008

Seismic profiler investigations have confirmed that the marginal channel that occurs on the Labrador Shelf separates crystalline Precambrian rocks underlying the inner shelf from sedimentary rocks on the outer shelf. The relief of the channel is thought to be mainly the result of glacial erosion, but there is also evidence of structural disturbance associated with this feature. Most seismic profiler transects show pronounced upwarping of the sedimentary strata underlying the seaward side of the marginal channel. One explanation offered for this upwarping is that it may possibly be due to isostatic adjustment following removal of material by glacial erosion.
Postglacial faulting and seismicity in New York and Quebec
Authors: Oliver Jack , Johnson Tracy , Dorman James
Published: October 2008

Within the last few years studies of relationships among faulting, fault creep, and seismicity in active areas such as California and Nevada have progressed rapidly, and have contributed greatly to our understanding of tectonics and the earthquake mechanism. This success prompted a field and literature search for similar phenomena in New York State and adjoining areas, a region of only moderate seismicity but of sufficient population density so that the seismic hazard should be thoroughly studied using all relevant information.Evidence for postglacial bedrock faulting, dated by offset striations, is common on outcrops of a belt of Paleozoic shales and slates that extends from near Hyde Park, New York, northerly along the east side of the Hudson and Champlain valleys, and continues northeasterly into Quebec at least as far as St. Georges. Faults tend to be in the plane of slaty cleavage with the south or east side upthrown in postglacial time. The observed faults are thus high-angle reverse faults with little or no postglacial strike–slip component. Displacement along a single fault is usually of the order of an inch or less, but commonly several such faults are seen in an outcrop only a few feet across. Thus, the faults seem very numerous, and cumulative displacement across a belt tens of miles in width could be quite substantial.An important question is whether this faulting is associated with glacial loading or unloading, with tectonic stresses, or with some other effect such as thermal changes, hydration, or a chemical process in the shales. Present data do not seem adequate to resolve this point, and a major purpose of this paper is to request similar information on other areas, particularly those adjoining the region of interest here. Casual observation of such faults would probably be dismissed by a geologist as slumping, frost heaving, or some other local disturbance in most cases if he were unaware of the regional pattern.Correlation between the pattern of observed faults and that of recent seismic activity is not highly convincing, but this could be because of inadequacies in either or both sets of data, so this question also remains open.
Isostatic response to loading of the crust in Canada
Authors: Walcott R. I.
Published: October 2008

A smoothed free air anomaly map of Canada indicates that the central part of the region occupied by the Laurentide Ice Sheet is over-compensated. Due to the close association of the free air gravity, the apparent crustal warping, the time of deglaciation, and the congruence of the gravity anomalies and the Wisconsin Glaciation, it is concluded that the over-compensation is due to incomplete recovery of the lithosphere from the displacement caused by the Pleistocene ice loads. The amplitude of the anomalies, about –50 milligals, suggests that a substantial amount of uplift has yet to occur and that the relaxation time of crustal warping is of the order of 10 000 to 20 000 y.The profile of the ground surface at the edge of a continental ice sheet on an elastic lithosphere is assessed using a value of the flexural parameter of the lithosphere calculated from gravity and deformation studies in the Interior Plains. The conclusions are: (a) a purely elastic forebulge is not likely to reach an amplitude of more than a few tens of meters; (b) the crust will be depressed for a considerable distance beyond the edge of the ice sheet; and (c) for large ice sheets crustal failure will probably occur in a preferential zone several hundred kilometers inside the maximum ice limit.
Evolutionary implications of tooth replacement in the Paleocene mammal Pararyctes
Authors: Fox Richard C.
Published: October 2008

A specimen of the palaeoryctid Pararyctes (Mammalia: Eutheria), from Paleocene strata of Alberta, shows nearly the complete replacement pattern of the dentition. Unexpectedly, premolars at two positions are seen replacing dP4, whereas the premolars at the anteriormost three positions seem not replaced or shed. The resulting total of concurrently functional teeth at five premolar and three molar positions, while mimicking that in certain ancestral eutherians, is clearly a derived character state, achieved independently. Furthermore, this pattern is inconsistent with the assumptions that deciduous and permanent teeth need belong to the same tooth families and that identical adult dental formulae are secure guides to homology.
Late Quaternary sediments and geomorphic history of northern Vancouver Island, British Columbia
Authors: Howes D. E.
Published: October 2008

Materials from two glacial intervals and one nonglacial interval have been identified on northern Vancouver Island, British Columbia. The oldest Pleistocene unit, termed "older drift," consists of glaciomarine silt and clay >38 000 years BP in age that overlie a till that has only been recorded in well logs. "Older drift" is tentatively correlated with Dashwood drift of the Semiahmoo Glaciation (early Wisconsin or older). No sediments of the succeeding Olympia nonglacial interval (mid-Wisconsin) have been found in the area. It is thought that this interval was characterized by a period of degradation in which Olympia-age sediments were deposited in transient sedimentary environments and subsequently eroded, in part during the Fraser Glaciation (late Wisconsin). The youngest Pleistocene unit, termed Port McNeill drift, includes advance deposits, till, and deglacial sediments, all deposited during Fraser Glaciation. Ice of this glaciation did not cover most of northern Vancouver Island until after 20 600 ± 330 years BP. At the maximum, which probably occurred about 15 000 years ago, Coast Mountain ice coalesced with and overrode Vancouver Island ice, and flowed in a westerly to northwesterly direction across northern Vancouver Island. Deglaciation commenced prior to 12 930 ± 160 years BP and possibly as early as 13 630 years ago on the eastern coast. Maximum sea level during and immediately following deglaciation was about 92 and 20 m elevation on the east and west coasts, respectively. This suggests that ice thickness at the Fraser maximum decreased westward across the study area. Deposits of Recent time include colluvial sediments formed by weathering and mass movement processes, alluvial fan and floodplain deposits, eolian sands associated with active beaches on the west coast, and organic deposits.
The Pliensbachian ammonite Dayiceras dayiceroides and Early Jurassic paleogeography
Authors: Smith Paul L.
Published: October 2008

Uptonia? dayiceroides Mouterde is placed in the genus Dayiceras and its age established as latest Jamesoni Zone to possibly earliest Domerian. The species is abundant and associated with faunas of Tethyan aspect along the northeastern Pacific margin. First occurrences in Oregon and Nevada and new occurrences in British Columbia are reported. Localities at apparently high paleolatitudes are attributed to post-early Pliensbachian transcurrent fault displacements. Genetic continuity with a disjunct population in Portugal is postulated via a central Atlantic seaway, here named the Hispanic Corridor, connecting the eastern Pacific and western Tethys Oceans. The existence of this corridor during the Pliensbachian is supported by several lines of independent paleobiogeographic evidence.
The age and origin of Grenville Province uraniferous granites and pegmatites
Authors: Fowler A. D. , Doig Ronald
Published: October 2008

Uranium mineralization in pegmatites and granites occurs widely in the Grenville Province but is especially important near Bancroft, Ontario and north of Mont Laurier and Johan Beetz in Quebec. Most investigators have concluded that these rocks were produced by anatexis of a uranium-enriched sedimentary protolith. We have used Rb–Sr isotopic methods to test this and other hypotheses and have reexamined the petrologic and structural features that led to these hypotheses.Rb–Sr whole-rock isochron ages from all three areas range from 937 to 980 Ma, some 150 Ma younger than the age of the peak of Grenville metamorphism as inferred from numerous ages from syntectonic intrusive rocks and high-grade metasediments. The ages of the pegmatites are similar to or just slightly greater than K–Ar ages from this region. The initial 87Sr/86Sr ratios range from 0.7028 to 0.7054, plus one poorly defined value of 0.709. Excluding this last one, these values are only slightly greater than mantle ratios, and calculations show that these rocks could not have been derived from the quartzofeldspafhic gneisses of these areas and certainly not from Grenville Supergroup sediments.The late timing of the emplacement of these rocks and the popularity of a continental collision model for the Grenville Province producing a very thick crust lead us to suggest an origin by deep melting due to isothermal decompression during rapid uplift. This suggestion is supported by the location of all the occurrences near zones interpreted to be paleorift systems.
Paleomagnetic results from the upper Keweenawan Chequamegon Sandstone: implications for red bed diagenesis and Late Precambrian apparent polar wander of North America
Authors: McCabe Chad , Voo Rob Van der
Published: October 2008

Two components of magnetization have been isolated from Chequamegon Sandstone samples using chemical demagnetization. A characteristic magnetization resides in magnetite of detrital origin. The pole calculated from this magnetization is 12.3°S, 177.7°E (K = 111.5, A95 = 4.6°). This pole lies with other poles of late Keweenawan age and is very close to the Jacobsville Sandstone poles. A secondary magnetization resides in authigenic hematite and yields a pole close to the present north pole. This high-latitude pole is known from an earlier study of the Chequamegon and has been used as evidence for the Hadrynian APW track. However, most if not all of the high-latitude poles that define the Hadrynian track are secondary and undated. Our preferred alternative to the Hadrynian track is that the high-latitude poles are recent remagnetizations and that the antipodal equatorial poles that mark its end points represent field reversals.
Downward water movement into frozen ground, western arctic coast, Canada
Authors: Mackay J. Ross
Published: October 2008

Field studies carried out mainly since 1975 in permafrost areas of Alaska, Canada, China, and the Soviet Union have been combined with the results of laboratory investigations to show that in summer water can move from the thawing active layer into the subjacent frozen active layer and under certain conditions even into the top of permafrost. Direct field evidence discussed includes: data from drilling and neutron probe logging, which show a summer increase in the ice content of already frozen ground; summer heave of heavemeters, with heave occurring in the frozen active layer; and increase in the ice content of the subjacent frozen ground in both permafrost and non-permafrost areas, caused by snowmelt infiltration. Indirect field and laboratory evidence is also added to support the direct lines of evidence. The conditions that favor the downward migration of water from thawed to frozen ground are examined in terms of thermally induced hydraulic gradients, hydraulic conductivity, content of unfrozen pore water, temperature gradients, ice content, and gravity. Some geocryologic implications of the summer growth of ice in frozen ground, including the effects on water balance calculations and the origin of patterned ground, are briefly mentioned.