bluuebunny/crossref_metadata_2025 huggingface dataset:
THE DEVELOPMENT AND ULTRASTRUCTURE OF ECTOMYCORRHIZAS
Authors: DUDDRIDGE J. A.
Published: May 2006

Summary

The effect of the presence of an exogenous carbon source in the synthesis medium on compatible and incompatible interactions between Suillus grevillei (Klotzsch) Sing, and a number of ectomycorrhizal hosts has been studied at the ultrastructural level. Comparisons are made with the results of the previous study in which carbohydrate was omitted. Observations suggest that the availability of an external source of carbon to the fungus upsets the balance of the symbiosis in favour of the fungal partner, even in compatible interactions, causing changes in the host cell wall and at the host‐fungus interface. The rate and degree of colonization of the root surface is also influenced by the presence of carbohydrate in the synthesis medium. These results suggest that any in vitro studies undertaken on compatibility and specificity in ectomycorrhizal associations should omit carbohydrate from the medium or use an aseptically synthesized donor host as the source of fungal inoculum.
WATER RELATIONS AND ULTRASOUND EMISSIONS OF PINUS SYLVESTRIS L. BEFORE, DURING AND AFTER A PERIOD OF WATER STRESS
Authors: PEÑA JOSÉ , GRACE JOHN
Published: May 2006

Summary

Using potted plants in a glasshouse, the relationship between ultrasound emission rate and water potential was investigated before, during and after a period of simulated drought. At the start of the experiment, just before budbreak, the plants emitted ultrasound pulses at rates of up to 25 c.p.m. During drought the rate increased to 60 c.p.m. Droughted plants displayed lower xylem density than the controls; and on this basis it was estimated that a third of the tracheids had emptied as a result of cavitation. On rewatering, the density of the xylem recovered and, after recovery, the plants that had been droughted failed to produce ultrasound emissions when water potential fell. By this time, the control plants, which had been well watered all the time, produced only a small number of ultrasound emissions when water potential fell.
INTERACTIVE EFFECTS OF CADMIUM, COPPER AND NICKEL ON THE GROWTH OF SITKA SPRUCE AND STUDIES OF METAL UPTAKE FROM NUTRIENT SOLUTIONS
Authors: BURTON K. W. , MORGAN E. , ROIG A.
Published: May 2006

Summary

The interactive effects of Cd, Cu, and Ni were studied in Sitka spruce [Picea sitchensis (Bong.) Carr] seedlings grown in nutrient solutions supplemented with combinations of these metals over three experiments of 3 × 3 × 3 factorial design. The results indicated that the toxic effects of Cd and Cu may be additive when both metals are present at concentrations which individually reduce yields, and that tree growth at several forestry sites in South Wales may be more severely affected than previously reported.

Analysis of variance of the concentrations of the added metals in the plants showed that concentrations of Cd in both roots and shoots were significantly reduced by Cu treatments (P < 0.01) and that this effect was especially pronounced at the highest concentrations of Cd and Cu (significant Cd × Cu interaction, P < 0.01). Analysis of variance of the concentrations of the nutrients Zn, Mg, Mn, and Ca in roots and shoots showed that both Cd and Cu significantly (P < 0.01) reduced the concentrations of Mn, and also interactively affected these (P < 0.01). Concentrations of Mg in the shoots were also significantly reduced by Cu treatments.
PHOTOSYNTHESIS OF COTYLEDONS OF SOYBEAN SEEDLINGS
Authors: HARRIS MARGARET , MACKENDER RICHARD O. , SMITH DAVID L.
Published: May 2006

Summary

The rate of net photosynthesis in each of the foliar organs present on seedlings of Glycine max (L.) Merrill was measured by infrared gas analysis on the fourth day after sowing and every third day thereafter until 5 d after cotyledon abscission. Dark respiration rates for the whole seedling were also measured. Estimates of the daily net carbon assimilation were made using the sum of the net CO2 assimilatory rates for each foliar organ present and the dark respiration rate for the whole seedling. Rates of cotyledon photosynthesis were very low in comparison to the leaves, whether expressed per unit chlorophyll or unit area. Although the cotyledon contribution to seedling assimilation remained small throughout their lifetime, it was enough to balance seedling respiratory losses during days 7 to 10 prior to leaf expansion. Marked increases in the CO2 budget only occurred once primary leaf photosynthesis began on day 10. Net assimilation then increased rapidly as first, second and third trifoliate leaves expanded.
CARBOXYLATING ENZYMES OF SOYBEAN COTYLEDONS
Authors: HARRIS MARGARET , MACKENDER RICHARD O. , SMITH DAVID L.
Published: May 2006

Summary

The in vitro activities of ribulose‐1,5‐bisphosphate (RuBP) carboxylase and phosphoenol pyruvate (PEP) carboxylase enzymes extracted from soybean [Glycine max (L.) Merrill cv. Amsoy'71] cotyledons are correlated with cotyledon chlorophyll development. High levels of PEP carboxylase activity were found in the spongy mesophyll tissues of young cotyledons before greening occurred, but as the cotyledons developed, the activity of this enzyme fell rapidly and 13 d after sowing it had almost disappeared. RuBP carboxylase activity, in contrast, was concentrated in the palisade mesophyll and increased with chlorophyll content, reaching a peak on day 10. RuBP carboxylase activity then declined and by the onset of senescence was very low. In cotyledons whose senescence had been arrested by epicotyl removal, chlorophyll recovery was found to precede that of the activity of both carhoxylase enzymes. After a lag of 5 d, both enzymes showed increased activity in the palisade mesophyll, RuBP carboxylase activity being greater than that of PEP carboxylase.
CARBOHYDRATES IN ROOTS AND RHIZOMES OF PERENNIAL GRASSES
Authors: STEEN ELIEL , LARSSON KJELL
Published: May 2006

Summary

Roots and rhizomes were sampled in a three‐year‐old grass ley during one year using a mesh bag method and soil coring. Samples, collected after different growth periods (1, 2, 3, 4, 5, 6 and 12 months) and at different times of the year, were analyzed for carbohydrates and Klason lignin. Throughout the year the rhizomes contained more non‐structural carbohydrates (20 to 40% of the organic matter) than the roots (1 to 8%). The non‐structural carbohydrate content varied over the year with a maximum in autumn and minimum in early spring and summer after the first grass cut. Fructan was the predominant constituent in this fraction. Structural carbohydrates and Klason lignin showed relatively small variations over the annual cycle. The ratio between structural carbohydrates and Klason lignin showed little variation with time but differed between roots (19) and rhizomes (2.5). The xylose content was higher in the roots than in the rhizomes. Only small changes occurred with time in the relative composition of the structural carbohydrates. This consistency in composition implies that there was a difference between subterranean and aerial parts. In the latter, ageing is characterized by increased lignification and systematic changes in structural carbohydrates owing to the formation of secondary cell walls.
YIELD TURGOR OF GROWING LEAVES OF BETULA AND ACER
Authors: TAYLOR GAIL , DAVIES W. J.
Published: May 2006

Summary

Leaf growth of first year seedlings of silver birch (Betula pendula Roth.) and sycamore (Acer pseudoplatanus L.) was measured continuously using linear variable transducers (LVTDs) when shoots were enclosed in small Perspex chambers, in which temperature, vapour pressure deficit (VPD) and photon fiuence rate were all controlled. A new method was used to measure the yield turgor (Y) of growing leaves. The VPD of air in the chamber was altered so that transpiration rate was changed. Turgor pressures, measured using thermocouple psychrometers, and growth rates varied as a result of this treatment, and the relationship between leaf growth and turgor pressure (P) and the turgor pressure at which growth ceased (Y) could be measured within a very short time period using well‐watered plants.

The value of Y was constant for illuminated and darkened leaves of both species, but Y was higher for sycamore leaves (Y= 0.250 MPa) compared with the value for birch leaves (K = 0.071 MPa).

Cell wall extensibility (w, MPa−1 h−1) was calculated from the slope of the line relating turgor pressure to growth. For leaves of birch, there was a significant increase in m when leaves were illuminated (m, dark = 1.3 × 10−2 MPa−1 h−1; m, light = 46 × 10−2 MPa−1), similar in magnitude to the increase in wall extensibility measured previously by mechanical analysis of killed leaf tissue (WEX, the plasticity of tissue subjected to a uniaxial stress). No change in m was detected when darkened sycamore leaves were illuminated (m, dark = 4.2 × 10−2 MPa−1 h−1; m, light = 4.4 × 10−2 MPa−1 h−1).

The results confirm earlier work on the factors controlling the diurnal patterns of leaf growth of these two species and suggest that leaf growth of birch is primarily limited by cell wall loosening but that the growth of sycamore leaves may be limited by leaf turgor.
UPTAKE AND TRANSLOCATION OF NITROGEN BY MILDEWED BARLEY SEEDLINGS
Authors: MURRAY A. J. S. , AYRES P. G.
Published: May 2006

Summary

The uptake of nitrogen (N) by roots, reciprocal transport of N between root and shoot, and reduction of nitrate in both root and shoot were examined in order to determine how the use of N in barley seedlings is affected by powdery mildew infection in both pre‐ and post‐sporulation phases. Plants were grown in culture solution supplying only nitrate‐N. The amount of N translocated in the xylem was calculated as the product of the concentration of N in the xylem sap and the flow rate of sap through the plant. The difference between this amount and the net increment of N in the shoot, which (like that of the root) was measured directly, was taken as being equal to the amount of N translocated in the phloem from the shoot to the root.

Infection inhibited N uptake and lowered total amounts of N in roots and shoots both before and during sporulation. Effects of mildew on N content per unit dry weight of tissue were more complex and depended on the stage of infection. The rates of nitrate reduction by the shoots and roots were also altered by infection. Before sporulation, nitrate reduction in the shoots was unaffected by infection, while the rate of reduction in the roots was depressed. After sporulation began, nitrate reduction stopped in the shoots but increased in the roots.

Relatively small amounts of N were measured in the fungal mycelium and conidia, and it was concluded that direct losses of N from leaves did not markedly affect the nitrogen budget. During sporulation, infection stopped the normally important recycling of N from the shoots to the roots. In both healthy and infected plants, the proportion of N recycled to the roots was higher when plants were grown on a low N supply than when grown on a high N supply. Root growth was affected by infection to a greater extent on the lower supply of N. The significance of the change in the rate of recycling of N to the roots for growth is discussed.
COMPARISON OF PROCHLORON FROM DIFFERENT HOSTS
Authors: COX GUY
Published: May 2006

Summary

Prochloron cells from a variety of ascidian hosts and from sites throughout the tropical Pacific and Indian Oceans have been studied by optical and electron microscopy. With a few exceptions, they can be placed into three typological groups which correlate closely with the type of host–symbiont relationship. This grouping is also compatible with the limited biochemical taxonomic data so far published on Prochloron. Some inferences can be drawn about the evolution of Prochloron and its symbiosis with ascidians.
THE ECOLOGICAL SPECIALIZATION OF DICOTYLEDONOUS FAMILIES WITHIN A LOCAL FLORA: SOME FACTORS CONSTRAINING OPTIMIZATION OF SEED SIZE AND THEIR POSSIBLE EVOLUTIONARY SIGNIFICANCE
Authors: HODGSON J. G. , MACKEY J. M. L.
Published: May 2006

Summary

Variation in seed size is an ecological paradox. Seed size, an important determinant of ecological distribution, is subject to considerable selection pressure, yet intra‐family variation in seed size in the Sheffield region of Central England is less than expected.

Taxonomically‐linked constraints of variation result from: number of ovules per carpel (solitary or numerous); placentation type (apical, basal or axile, parietal); presence or absence of endosperm in the ripe seed and the pattern of embryogenesis (Asterad, Chenopodiad or Caryophyllad, Onagrad, Solanad). These character states are not readily modified and tend to be conservatively expressed in families. The smaller‐ and larger‐seeded families of the local flora are characterized by different combinations of these features. Larger‐seeded families may be further subdivided into those from moist or relatively dry habitats. It is suggested that the presence of a starchy endosperm, an unusual feature in the dicotyledons, may allow the development of a high root/shoot ratio in the young seedling. From extrapolation, it is suggested that (a) optimization of ecologically important characteristics and (b) adaptive radiation of major taxa during the evolutionary history of the angiosperms may have been restricted by these relatively stable groups of characters.
Caesarean section on request: a comparison of obstetricians’ attitudes in eight European countries
Authors: Habiba M , Kaminski M , Da Frè M , Marsal K , Bleker O , Librero J , Grandjean H , Gratia P , Guaschino S , Heyl W , Taylor D , Cuttini M
Published: May 2006

Objective  To explore the attitudes of obstetricians to performe a caesarean section on maternal request in the absence of medical indication.

Design  Cluster sampling cross‐sectional survey.

Setting  Neonatal Intensive Care Unit (NICU) associated maternity units in eight European countries.

Population  Obstetricians with at least 6 months clinical experience.

Methods  NICU‐associated maternity units were chosen by census in Luxembourg, Netherlands and Sweden and by geographically stratified random sampling in France, Germany, Italy, Spain and UK. An anonymous, self‐administered questionnaire was used for data collection.

Main outcome measures  Obstetricians’ willingness to perform a caesarean section on maternal request.

Results  One hundred and five units and 1530 obstetricians participated in the study (response rates of 70 and 77%, respectively). Compliance with a hypothetical woman’s request for elective caesarean section simply because it was ‘her choice’ was lowest in Spain (15%), France (19%) and Netherlands (22%); highest in Germany (75%) and UK (79%) and intermediate in the remaining countries. Using weighted multivariate logistic regression, country of practice (P < 0.001), fear of litigation (P= 0.004) and working in a university‐affiliated hospital (P= 0.001) were associated with physicians’ likelihood to agree to patient’s request. The subset of female doctors with children was less likely to agree (OR 0.29, 95% CI 0.20–0.42).

Conclusions  The differences in obstetricians’ attitudes are not founded on concrete medical evidence. Cultural factors, legal liability and variables linked to the specific perinatal care organisation of the various countries play a role. Greater emphasis should be placed on understanding the motivation, values and fears underlying a woman’s request for elective caesarean delivery.
Studies of P accumulation in soil/sediment profiles used for large‐scale wastewater reclamation
Authors: Lin C. , Eshel G. , Roehl K. E. , Negev I. , Greenwald D. , Shachar Y. , Banin A.
Published: May 2006

We studied the long‐term accumulation processes and material balances of phosphorus (P) in the soil/sediment profiles of large‐scale effluent recharge basins used for wastewater reclamation by the soil aquifer treatment (SAT) system. The objective was to quantify and clarify the long‐term performance of soil/sediment in the SAT system as a sorbent to filter out P from the recharged effluent. Total P concentration in the soil/sediment profiles of the Shafdan wastewater treatment plant (WWTP) increased over 25 years of operation (1977–2001) by 20–220 mg kg−1, as a result of adding loads of 0.17–6.2 kg m−2of P. Retained P in the 0–2.0 m soil layer increased from 0.06 to 0.31 kg m−2with increasing cumulative load of P while the retained percentage gradually decreased from 19 to 5% of the cumulative P load. Accumulation rate of P in the 0–0.15 m horizon in the basins was inversely proportional to recharge time, decreasing from ∼28 mg P kg−1 year−1during the first 3 years of operation, to <2.3 mg P kg−1 year−1between the 20th and 25th years of operation. Thus, P content in this horizon approached a steady state after about 10–15 years of effluent recharge under the operational conditions of the Shafdan WWTP. Phosphorus concentration in deeper horizons increased at constant rates of approximately 7.8, 5.9 and 2.9 mg P kg −1 year−1in the 0.15–0.30, 0.30–0.60 and 1.80 to 2.10‐m horizons, respectively, over the 25 years of effluent recharge. However, the accumulation front of P appears gradually to have moved deeper in the soil profile. In general, this phenomenon may be explained by kinetic limitations to the achievement of full adsorption equilibrium for P between the flowing solution and the solid phase components of the soil. In addition, both the increase of EPC0(the equilibrium P concentration in solution at which there is no sorption or desorption to or from the soil under the given conditions), caused by long‐term effluent recharge, and gradual decrease of the annual average concentration of P in the effluent input after 1995, may result in the steady‐state level of P in the topsoil of the basin.
Towards a World Soil Survey Archive and Catalogue
Authors: Hallett S. H. , Bullock P. , Baillie I.
Published: May 2006

An extensive collection of soil, land resource and land suitability surveys undertaken worldwide over the last 80 years by soil surveyors and scientists at the behest of the British government and others has been archived and catalogued using internationally recognized bibliographic standards. The World Soil Survey Archive and Catalogue (WOSSAC) consisting of over 13 000 reports and maps is now available for consultation and use by the international soil science community.
Impact of pegylated interferon α‐2B and ribavirin on hepatic fibrosis in liver transplant patients with recurrent hepatitis C: an open‐label series
Authors: Mukherjee Sandeep , Lyden Elizabeth
Published: May 2006

Abstract: Background: Patients with recurrent hepatitis C virus (HCV) are often treated with interferon‐based therapy in an attempt to eradicate HCV and prevent cirrhosis requiring retransplantation. We describe our experience with pegylated interferon and ribavirin and the impact of this therapy on hepatic fibrosis.

Methods: Patients were treated with pegylated interferon α‐2b 1.5 mcg/kg/week and ribavirin 800 mg/day for 6–12 months according to genotype. HCV ribonucleic acid (HCV RNA) was repeated at 3 months, end of treatment (EOT) and 6 months after EOT for patients HCV RNA negative at EOT. Liver biopsies were performed prior to treatment and at EOT.

Results: Thirty nine patients were eligible. Twenty two completed treatment and 17 (43.6%) were intolerant. Eleven of 22 (50%) patients who completed treatment developed sustained viral response (SVR). Two patients intolerant to treatment also developed SVR. Serial biopsies were performed in 17 patients and refused in five. Improved fibrosis scores were present in four patients (non‐responders, n=2), unchanged in 10 (non‐responders, n=4), and worse in three (all non‐responders).

Conclusions: Side effects are an important limiting factor in recurrent HCV treatment with SVR only 33.3% in an intention‐to‐treat analysis. However, improved or stable fibrosis scores were also demonstrated in 66.7% of non‐responders. This suggests failure to eradicate HCV should not necessarily lead to treatment discontinuation as a subgroup of patients may benefit from maintenance therapy.
Therapeutic advances in systemic lupus erythematosus
Authors: MOK C. C.
Published: May 2006

Despite the improvement in survival of patients with systemic lupus erythematosus (SLE) in the past few decades, manifestations that are refractory to conventional therapies, and complications as a result of treatment, are still major concerns in SLE management. Novel therapeutic modalities for SLE should aim at enhancing treatment efficacy, reducing the risk of disease flares, as well as decreasing the incidence of short‐term and long‐term toxicities. This article summarizes the newer therapeutic modalities that have been used in patients with SLE and those which are undergoing clinical trials.
Guidelines for diagnosing, prevention and treatment of osteoporosis in Asia
Authors: LAU E. M. C. , SAMBROOK P. , SEEMAN E. , LEONG K. H. , LEUNG P. C. , DELMAS P.
Published: May 2006

According to the World Health Organization criteria, osteoporosis can be defined as a bone mineral density of −2.5 or more. Dual X‐ray densitometry is the recognised method for diagnosing osteoporosis. Drugs which have been shown to be efficacious in treating osteoporosis include alendronate, residronate, ibandronate, raloxifene, teriparitide and strontium ranleate. Patients with established osteoporosis should be treated. Primary prevention of osteoporosis is important at the community level.
Quality of life in young fibromyalgia patients and effect of depression
Authors: GUR Ali , CEVIK Remzi , NAS Kemal , SARAC Aysegul Jale , OZEN Sakir
Published: May 2006

Aim:  The purpose of this study was to compare the depression and quality of life (QOL) scores of fibromyalgia (FM) patients and control subjects. We also aimed to detect relationships between different QOL scales, depression and clinical symptoms.

Method:  Ninety‐eight fibromyalgia patients and 48 healthy volunteers were included in the study. Depression was evaluated by a psychiatrist according to the Hamilton Depression Rating Scale and Diagnostic and Statistical Manual for Mental Disorders Edition 4 (DSM‐IV) criteria. QOL of the FM patients was assessed according to the Nottingham Health Profile (NHP), Health Assessment Questionnaire (HAQ), and Fibromyalgia Impact Questionnaire (FIQ).

Results:  We found significantly higher scores of depression, NHP, FIQ and HAQ in FM patients compared with controls (P < 0.000). Pain, tender point count (TPC), pain intensity, skinfold tenderness, FIQ, HAQ, and NHP scores were higher in patients with depression than in those without depression. Depression scores correlated with FIQ (r = 0.39, P < 0.01), HAQ (r = 0.35, P < 0.01), NHP (r = 0.55, P < 0.01) scores, TPC (r = 0.34, P < 0.01) and duration of disease (r = 0.21, P < 0.05). Fibromyalgia Impact Questionnaire scores correlated with HAQ scores (r = 0.45, P < 0.01), NHP scores (r = 0.49, P < 0.01) and TPC (r = 0.21, P < 0.05). HAQ scores correlated with NHP scores (r = 0.40, P < 0.01) and TPC (r = 0.29, P < 0.05). Nottingham Health Profile scores correlated with TPC (r = 0.43, P < 0.01) and duration of disease (r = 0.22, P < 0.05).

Conclusion:  We found higher scores of TPC, pain intensity, skinfold tenderness, NHP, FIQ, and HAQ in depressive FM patients as compared with non‐depressive FM patients. Our study indicates that there is an important relationship between pain, depression and QOL scales in young FM patients. Therefore; these patients should be managed using a multidisciplinary approach including psychiatric support.
Infections in patients with systemic lupus erythematosus
Authors: NG Woon‐Leung
Published: May 2006

Infection is a major contributor to morbidity and mortality in patients with systemic lupus erythematosus (SLE). In most clinical series, infection ranks first or second as the most common cause of death in SLE patients worldwide, including Hong Kong. In this article, the spectrum of infections and their protean manifestations in lupus patients will be reviewed with emphasis on clinical data from Hong Kong and other Asian countries. A high index of suspicion and dedicated work‐up to identify the causative pathogens is pivotal to the early diagnosis and effective management of infective complications in patients with SLE.
Clinical approach to patients with joint disease: importance of distinguishing inflammatory from non‐inflammatory conditions
Authors: MALAVIYA Anand N.
Published: May 2006

The widening gap between demand and supply of trained rheumatologists to deal with enormous numbers of patients with musculoskeletal (MSK) diseases, especially in the South‐East Asian region, was the topic of a recent oration. A possible temporary solution to the problem was offered. It was suggested that the entire time and energy of available rheumatologists may be focused only toward patients with systemic inflammatory autoimmune diseases. The argument was that these are serious life‐threatening conditions requiring urgent specialist (rheumatologist‐physician) referrals for early aggressive treatment with disease modifying antirheumatic drugs/biologicals to save permanent MSK damage and premature death. Crucial to this arrangement would be to have primary care physicians and orthopaedic surgeons who could quickly recognize serious systemic inflammatory MSK diseases (the so‐called ‘red‐flag’ conditions) from local/regional/biomechanical structural damage‐related MSK diseases (the so‐called ‘green‐flag’ conditions). Only the ‘red‐flag’ conditions may then be referred to the rheumatologist‐physician for detailed evaluation and appropriate drug therapy. This article describes a simple clinical approach for quick distinction between these two categories of MSK diseases. Rheumatologists may like to use this approach to conduct continuing medical education (CME) programs targeted towards primary care physicians and orthopaedic surgeons so that ‘red flag’ MSK disease patients reach rheumatologist‐physicians as soon as possible.
Reflex sympathetic dystrophy syndrome: a clinicoradiologic study
Authors: HANDA Rohini , SHANKAR S. , BAL C. S.
Published: May 2006

Aim:  To describe the clinico‐radiologic profile of patients with reflex sympathetic dystrophy syndrome.

Methods:  Patients diagnosed with RSDS according to criteria proposed by the International Association for Study of Pain and attending a large rheumatology clinic in north India are described.

Results:  Fourteen patients (8 male, 6 female) were seen over a 3‐years period. Clinical features included extremity pain (100%), vasomotor symptoms (79%), hyperalgesia (72%), allodynia (36%), sudomotor symptoms (14%) and motor dysfunction (14%). Radiologic features included osteopenia (50%) and soft tissue swelling (7%). As many as 43% of patients exhibited normal radiographs. Technetium 99 m 3‐phase bone scintigraphy was abnormal in all patients in our series. Eleven of the 14 patients exhibited symptomatic response to non‐steroidal anti‐inflammatory drugs and corticosteroids.

Conclusions:  Reflex sympathetic dystrophy syndrome is a pain syndrome occasionally encountered by rheumatologists. Extremity pain is the most common presenting feature. Bone scintigraphy is very useful in corroborating the diagnosis even when radiographs are normal.
HeartQuest Ventricular Assist Device Magnetically Levitated Centrifugal Blood Pump
Authors: Bearnson Gill B. , Jacobs Gordon B. , Kirk John , Khanwilkar Pratap S. , Nelson Karl E. , Long James W.
Published: May 2006

Abstract:  Improvements in implantable ventricular assist device (VAD) performance will be required to obtain patient outcomes that are comparable with those of heart transplantation. The HeartQuest VAD (WorldHeart, Oakland, CA, U.S.A.) is an advanced device, with full magnetic suspension of the rotor, designed to address specific clinical shortcomings in existing devices and to maximize margins of safety and performance for an implantable assist device. The device dimensions are 35 × 75 mm, with a total weight of 440 g. The system was designed using extensive computer modeling of device function; a total of two iterations of device prototypes were built before building the clinical version. Animal study results have been very promising, with over 30 calf studies completed. Plasma‐free hemoglobin levels returned to preoperative levels, and other hematology results were in the normal ranges. Highlights include clean surfaces seen in a 116‐day experiment with no anticoagulation after day 43. Feasibility clinical trials are planned to start in 2006.
A Review of Leakage Flow in Centrifugal Blood Pumps
Authors: Chan Weng‐Kong , Wong Yew‐Wah
Published: May 2006

Abstract:  This article presents a new approach in determining the functional relationship between the leakage flow in a centrifugal blood pump and various parameters that affect it. While high leakage flow in a blood pump is essential for good washout and can help prevent thrombus formation, excessive leakage flow will result in higher fluid shear stress that may lead to hemolysis. Dimensional analysis is employed to provide a functional relationship between leakage flow rate and other important parameters governing the operation of a centrifugal blood pump. Results showed that pump performance with a smaller gap clearance is clearly superior compared to those of two other similar pumps with larger gap clearances. It was also observed that the nondimensional leakage flow rate varies almost linearly with dimensionless pump head. It also decreases with increasing volume flow rate. A smaller gap clearance will also increase the flow resistance and hence, decrease the nondimensional leakage flow rate. Increasing surface roughness, length of the gap clearance passage, or loss coefficient of the gap geometry will increase losses and hence, decrease the leakage flow rate. It is also interesting to note that for a given pump and gap clearance geometry, the nondimensional leakage flow rate is almost independent of the Reynolds number when specific speed is constant.
Allele Frequencies for Three STR Loci D10S1418, D8S1477, and D10S1426 in a Chinese Population
Authors: Tian Li , Bai Peng , Hong Song Xiao , Jia Jing , Yuan Wan An , Yun Li Bing , Zhang Ji , Wu Jin , Li Ying Bi
Published: May 2006

POPULATION: Chinese (n=100).
Population Genetics for Five STR Loci in Tibetan Group of Chinese Population
Authors: Huang Jin , Fan Hong , Li Hong , Jiang Fei , Ying Bin Wu
Published: May 2006

POPULATION: Chinese (n=131).
Population Data for Four Population Groups from the United States for the Eleven Y‐Chromosome STR Loci Recommended by SWGDAM
Authors: Shewale Jaiprakash G. , Bhushan Anurag , Nasir Huma , Schneida Elaine , Washington Brandi , Fleming Alison , Sinha Siddartha K. , Gross Ann M. , Budowle Bruce , Sinha Sudhir K.
Published: May 2006

POPULATIONS: Caucasian (n=1243), African American (n=1605), Hispanic (n=454), and Native American (n=104).
Partisanship, Party Coalitions, and Group Support, 1952‐2004
Authors: STANLEY HAROLD W. , NIEMI RICHARD G.
Published: May 2006

Recent changes in partisan support suggest the beginning of a new group basis for the party coalitions. For the Republicans, the changes define group support more sharply than has been the case for many years—a combination of southern whites and a strong religious base of Catholics, regular church‐goers, and Protestant fundamentalists. For Democrats, the changes are defined in terms of losses—of Catholic, union household, and regular church‐going voters—not sufficiently offset by the increased support of women and the growing Hispanic population. The problem for Republicans is to maintain and enhance a heterogeneous coalition, including a fragile religious combination. The problem for Democrats is to find new coalition partners or regain support that the party has lost.
A post-mortem investigation of the Type IIb supernova 2001ig
Authors: Ryder Stuart D. , Murrowood Clair E. , Stathakis Raylee A.
Published: May 2006

We present images taken with the Gemini Multi-Object Spectrograph on Gemini-South, in excellent (<0.5 arcsec) seeing, of supernova (SN) 2001ig in NGC 7424, ∼1000 d after explosion. A point source seen at the site of the SN is shown to have colours inconsistent with being an H ii region or a SN 1993J-like remnant, but can be matched to a late-B through late-F supergiant with AV < 1. We believe this object is the massive binary companion responsible for periodic modulation in mass-loss material around the Wolf–Rayet progenitor which gave rise to significant structure in the SN radio light curve.
COMPOSITIONAL HETEROGENEITY OF BUTADIENE–ACRYLONITRILE COPOLYMERS PREPARED IN EMULSION AT 5°C
Authors: Embree W. H. , Mitchell J. M. , Williams H. Leverne
Published: May 2006

The copolymerization of butadiene and acrylonitrile is very similar to the copolymerization of butadiene and styrene. Polymers predominantly butadiene may be studied by conventional solution techniques but the study of polymers rich in acrylonitrile requires improved solvents for these materials. Polymerization rates are greatest for monomer ratios approximating equal proportions. The mercaptan modifier disappears much more slowly than in the butadiene–styrene system, the regulating index approximating unity. The number average molecular weights calculated from the mercaptan disappearance curves indicate uniform polymer molecular weights to relatively high conversions after which there is a decrease. The viscosity data indicate a rise in viscosity with conversion, which effect is overcome for charges rich in acrylonitrile by the lessening of branching, the more rapid disappearance of mercaptan at high conversion, and the tendency of polymers containing over 50% acrylonitrile to show very low dilute solution viscosities in the solvents tested. Viscosity molecular weights have been calculated and estimates of the molecular weight distribution made. These distributions appear to be quite narrow and the usual broadening at higher conversions is prevented by the increased modifier consumption and increased vinyl content of the polymer prepared with 50 parts acrylonitrile in the charge. The bound acrylonitrile has been determined at various conversions and the reactivity ratios have been found to be r1 = 0.28 and r2 = 0.02 for emulsions and r1 = 0.18 and r2 = 0.03 for oil phase portion only. Q is 0.74 and e is 1.47 as calculated by the Alfrey–Price equations.
THE PAPILIONACEOUS ALKALOIDS: XI. IDENTITY OF GENISTEINE WITH l-α-ISOSPARTEINE
Authors: Marion Léo , Leonard Nelson J.
Published: May 2006

Genisteine has been shown to be identical with l-α-isosparteine by means of a direct comparison of the physical properties of the alkaloids and their corresponding derivatives.
THE SEPARATION OF THE RARE EARTHS BY ION-EXCHANGE PROCEDURES
Authors: Fitch F. T. , Russell D. S.
Published: May 2006

The iminodiacetic acids have been examined as possible complexing agents in the chromatographic separation of the rare earths with cation exchange resins. The ammonium salts of these acids form complex ions involving both one and two iminodiacetate ions of increasing stability with the rare earth elements of greater atomic number. Methods greatly reducing the time and material requirements are presented for the separation of the cerium group elements with nitrilotriacetic acid.
PREPARATION OF SUBSTITUTED NITROGUANIDINES AND THE CYCLIZATION OF N-γ-NITROXYBUTYL-N′-NITROGUANIDINE
Authors: Mckay A. F. , Thomas H. P.
Published: May 2006

Several new substituted nitroguanidines were prepared by the reaction of amines with N-methyl-N-nitroso-N′-nitroguanidine. N-γ-Nitroxybutyl-N′-nitroguanidine was cyclized to 1-nitro-2-amino-6-methyl-Δ2-tetrahydropyrimidinium nitrate by refluxing in water.
HYDROGEN PEROXIDE AND ITS ANALOGUES: III. ABSORPTION SPECTRUM OF HYDROGEN AND DEUTERIUM PEROXIDES IN THE NEAR ULTRAVIOLET
Authors: Phibbs M. K. , Giguère Paul A.
Published: May 2006

The absorption of ultraviolet light between 3000 and 4000 Å by solutions of hydrogen peroxide in water and of deuterium peroxide in heavy water has been measured at various concentrations. Both peroxides show slight but real deviations from Beer's law at high concentrations. Substitution of hydrogen by deuterium shifts the absorption continuum by about 390 cm.−1 towards shorter wave lengths. This shift is of the same order as that calculated from the difference in zero-point energy of the two isotopic molecules.
THE SYNTHESIS OF AMINO ACIDS FROM 2, 3-DIHYDROFURAN DL-ORNITHINE, DL-PROLINE, AND DL-α-AMINO-δ-HYDROXYVALERIC ACID
Authors: Gaudry Roger
Published: May 2006

not available
THE INFLUENCE OF CATION RADIUS AND SALT CONCENTRATION IN THE SALTING OUT OF ETHYL ETHER FROM AQUEOUS NITRATE SOLUTIONS AT 25°C.
Authors: Heal H. G.
Published: May 2006

The solubility of ethyl ether in aqueous solutions of the nitrates of the alkali metals, the alkaline earths and magnesium, and ammonium, tetramethyl, tetraethyl, and tetra-n-propyl ammonium has been measured with high precision. The salting out at infinite dilution of salt, estimated by extrapolation from data for salt concentrations below 0.1 molal, conforms in a general way to the Debye theory, with some discrepancies. Data for high salt concentrations are also given.
THE CHEMISTRY OF ETHYLENE OXIDE: III. REACTION OF ETHYLENE OXIDE IN AMINE SOLUTION
Authors: Eastham A. M. , Darwent B. deB.
Published: May 2006

A kinetic study has been made of the reaction of ethylene oxide in pyridine solution in the presence of strong acids. The rate has been found to be dependent upon the concentration of acid and of oxide over a wide range of concentrations at 25°C. The specific rate constant, however, varies markedly with the nature of the acid anion and appears to decrease with increasing basic strength of the anion. The absence of large salt effects seems to indicate that the anion effect is of a physical rather than chemical nature and the results are therefore tentatively attributed to the nature of solutions of electrolytes in solvents of low dielectric constant.
CONTRIBUTION TO THE THEORY OF DIFFUSION FLAMES
Authors: Cvetanović R. J. , Roy D. J. Le
Published: May 2006

In order to evaluate the rate constant for the reaction of atomic sodium with halides using the diffusion flame method, Hartel and Polanyi introduced three simplifying assumptions: that the mass flow of the carrier gas could be neglected, that there was a spherical distribution of sodium vapor in the reaction zone, and that the halide concentration was constant throughout the reaction zone. In an attempt to maintain the validity of the third assumption previous workers limited their experimental determinations to cases in which the collision yield was considerably less than unity. In the present contribution equations arc developed which remove this restriction and permit the evaluation of the rate constant without assuming a constant halide concentration. On carrying out the computation for a relatively slow reaction (Na + C2H5Cl) it was found that the error introduced by the third assumption was only of the order of 20%. The error for fast reactions would be considerably larger but can always be evaluated from the equations given. In some cases an approximate value of the error can be obtained without carrying out the complete computation.
THE ROLE OF AMORPHOUS INTERMEDIATE PRODUCTS IN THE DEHYDRATION OF CERTAIN HYDRATED SALTS
Authors: Frost G. B. , Moon K. A. , Tompkins E. H.
Published: May 2006

Following the dehydration of certain hydrated salts in high vacuum, an evolution of energy occurs. X-ray studies have shown that this energy liberation is due to an amorphous to crystalline transition in the products of dehydration. Measurements have been made of the integral heats of solution of the dehydration products of copper sulphate pentahydrate and zinc sulphate hexahydrate formed at a series of low dehydration pressures. From these measurements, the fractional amounts of relatively high energy amorphous products formed at a series of low dehydration pressures have been calculated. It has been found that as the water vapor pressure near the reaction interface is increased, the fractional amount of high energy product decreases to a minimum, then increases, passes through a maximum, followed by a slow decrease. These results are interpreted in terms of a possible dehydration mechanism, and an estimation made of the effect of water vapor pressure on the over-all reaction rate. In the course of this study, the integral heats of solution of the crystalline hydrates involved have been determined. The heats of transition of the amorphous to crystalline forms of copper and zinc sulphate monohydrates are reported.
STUDIES ON RDX AND RELATED COMPOUNDS: IV. THE BACHMANN OR COMBINATION PROCESS
Authors: Williams H. L. , Winkler C. A.
Published: May 2006

The effect of varying the concentrations of nitric acid and ammonium nitrate on the yield of RDX has been determined at 35°C., using hexamine, hexamine mononitrate, and hexamine dinitrate. The activation energies for the formation of RDX from hexamine, hexamine mononitrate, and hexamine dinitrate were found to be approximately 11 kcal., 12.5 kcal., and 16.5 kcal., respectively.
Aryldiguanidines
Authors: McKay A. F. , Hatton W. G.
Published: May 2006

Some aryldiguanidines were prepared by treating aryldiamines with cyanamide. These are described below in the experimental section.
ASSOCIATION OF CERIC IONS WITH SULPHATE (A SPECTRAL STUDY)
Authors: Hardwick T. J. , Robertson E.
Published: May 2006

Ceric ion has been shown to associate with sulphate ion to form successively Ce(SO4++, Ce(SO4)2, and Ce(SO4)3−. The association constants relating these species have been determined at 25 °C. The molar extinction coefficients of each associated complex have been found between 395 and 430 mμ. Migration experiments bear out the results qualitatively.
ELECTRONIC INTERPRETATION OF THE UNCATALYZED REACTION BETWEEN RESORCINOL AND FORMALDEHYDE IN ALCOHOLS AND DIOXANE
Authors: Ingram A. R.
Published: May 2006

The condensation of resorcinol and formaldehyde in aqueous alcohols and dioxane is interpreted on the basis of competing electrophilic reactions of the hydroxymethyl carbonium ion with the resorcinol aromatic ring and with the oxygen atoms of the resorcinol and the solvents. The reaction of the carbonium ion and the alcohol groups leads to oxonium ions which may then form hemiacetals.
COMPONENT FATTY ACIDS OF RAPESEED OIL
Authors: Youngs C. G. , Mallard T. M. , Craig B. M. , Sallans H. R.
Published: May 2006

The fatty acid composition of the oil from Argentine rapeseed grown in Western Canada was investigated by converting the glyceride esters to methyl esters and distilling the latter in a Podbielniak Heligrid distillation column. Analyses of the fractions showed 6 to 10% more eicosenoic acid and 7 to 10% less erucic acid than was previously reported for rapeseed oils.
THE ADDITION COMPOUNDS OF SILICON TETRACHLORIDE AND AMINES
Authors: Trost W. R.
Published: May 2006

Addition compounds formed between silicon tetrachloride and some amines have been prepared and analyzed. Molecular ratios of 4/1, 2/1, and 1/1 were established for amine to silicon tetrachloride in these compounds. It is suggested that these molecular compounds use 4s, 3d, 4p orbitals only, in forming the coordinate bonds that establish the compound, and that the configuration of the silicon tetrachloride remains essentially undisturbed. Use of these assumptions permits definite structural predictions to be made about the compounds.
PHYSICAL CONSTANTS AND ESTIMATION OF STEREOISOMERIC 2,3-BUTANEDIOLS
Authors: Watson R. W. , Coope J. A. R. , Barnwell J. L.
Published: May 2006

The refractive index – temperature relation for optically active and racemic diols is linear, with [Formula: see text] from 25° to 40°C.: for the meso-isomer [Formula: see text] from 25° to 50°C. The specific rotation [Formula: see text]. Measurements of [Formula: see text] and [Formula: see text] in suitably purified mixtures of stereoisomers allow calculation of the percentage of each isomer present. Tests of the method on known mixtures of all three stereoisomers show an experimental error of ±3%. Analyses of five diol samples from pilot plant fermentations of beet molasses by Aerobacter aerogenes reveal 65–87% meso-, from 2 to 16% dextro-, and from 0 to 33% racemic 2,3-butanediol.
THE STRUCTURE OF RYANODINE. I
Authors: Kelly R. B. , Whittingham D. J. , Wiesner K.
Published: May 2006

Ryanodine consumes one mole of periodic acid and gives oxoryanodine C25H33O9N. Splitting off water from ryanodine gives anhydroryanodine C25H33O8N. The analyses of these two derivatives are therefore in agreement with the formula for ryanodine C25H35O9N. Alkaline hydrolysis of ryanodine gives pyrrole-α-carboxylic acid and an alcohol C20H32O8. This alcohol splits off water to give a compound C20H30O7. Alkaline hydrolysis of oxoryanodine consumes three moles of alkali and gives a mixture of low molecular acidic products. Alkaline fusion of oxoryanodine gives a neutral aromatic nitrogen-free crystalline substance.
RELATIVE STABILITIES OF THE ISOMERIC CYCLOHEXANE-1,2,3-TRIOL TRINITRATES AND 1,2-DIOL DINITRATES
Authors: Christian W. R. , Purves C. B.
Published: May 2006

Of the above trinitrates, the cis-cis-cis and the cis-trans-cis isomers melted at 70° and 88°C, respectively, but the racemic cis-cis-trans form remained as a colorless viscid oil. When dissolved in excess 0.105 N aqueous–alcoholic sodium hydroxide at 20°C, the cis-cis-cis isomer hydrolyzed most rapidly but formed least nitrite, and the solution developed most color. The same isomer evolved the smallest amount of oxides of nitrogen when kept at 106°C., but was more readily detonated by shock than was the cis-trans-cis-trinitrate. The relative reactivities toward alkali and heat of the much more stable cis and tran-cyclo-hexane-1,2-diol dinitrates, which melted at 24° and 18.5°C., respectively, were as described for the trinitrates, but their relative sensitivities to shock were no less. All five compounds were new.
THE ROLE OF ALPHA-KETOLS IN THE LOW-SUGAR REDOX RECIPE FOR LOW TEMPERATURE EMULSION COPOLYMERIZATION
Authors: Orr R. J. , Williams H. Leverne
Published: May 2006

It was found that the induced decomposition of peroxy compounds could lead to faster rates of polymerization or practical rates of polymerization at lower temperatures. In Germany polymerization recipes were developed containing a peroxy compound in the oil phase, a reducer in the aqueous phase and a metal carrier. This idea was transferred to America after the war and became the basis of the present recipes used in the production of cold rubbers. As reducers the most commonly used appear to be digested d-glucose or an excess of ferrous iron but recently the polyamines and other amine compounds have been found to be quite effective. The mixture of amine and sugar was better than either alone. It has been shown that this mixture will function in the presence of reactive monomers such as acrylonitrile. The role of such reducers is of considerable interest so that further studies were undertaken. The results obtained may be illustrated by acetoin. As the amount of acetoin is increased in the recipe the amount of ferrous iron required for maximal conversion in a given time is decreased. This is because at higher than the optimal amounts, although the reaction rate is still increasing, the catalyst system is rapidly exhausted so that the reaction dies at a lower conversion. The data can be explained by assuming formation of free radicals by the induced decomposition of the peroxide either by the acetoin, the ferrous iron, or a complex between the iron and acetoin. This free radical then initiates polymerization. The acetoin free radical residue can induce the further decomposition of the peroxide or possibly can reduce ferric iron to ferrous. Other compounds yield similar results.