bluuebunny/crossref_metadata_2025 huggingface dataset:
Strength of Esophageal Closure Techniques With and Without Tissue Reinforcement
Authors: Yeginsu Ali , Ergin Makbule , Erkorkmaz Unal
Published: May 2007

Objectives

The purpose of this study was to investigate the effects of esophagotomy closure techniques on the esophageal bursting pressure.

Materials and methods

Altogether, 122 freshly dead sheep esophagi received from the local slaughterhouse were prepared for manual closure. After esophagotomy, the specimens were divided into four groups. An interrupted mucosal suture pattern (n = 30), an interrupted mucosal‐submucosal suture pattern (n = 30), an interrupted mucosal‐submucosal + over‐over continuous muscular suture pattern (n = 32), and an interrupted mucosal‐submucosal + reinforcement with a diaphragmatic part with full‐thickness interrupted U suture pattern (n = 30) were used for esophagotomy closure; 4‐0 silk was used in all specimens. Bursting pressures were measured with a sphygmomanometer.

Results

We found a statistically significant difference among the bursting pressures of all groups (p < 0.001). The bursting pressure values gradually increased from group 1 to group 4 (47.6 ± 22.7, 86.2 ± 49.5, 185.4 ± 53.5, and 226.8 ± 62.4 mmHg, respectively). Reinforcing the esophageal suture line with tissue significantly increased the bursting pressure compared to the other groups.

Conclusions

Each layer of the esophagus significantly contributes to strengthening esophageal wall tension with primary esophageal closure, and reinforcement of the esophageal suture with tissue provides an additional significant increase in the bursting pressure of the esophagus.
Serum Levels of Uric Acid and Diabetes Mellitus Influence Survival after Surgery for Primary Hyperparathyroidism: A Prospective Cohort Study
Authors: Bergenfelz Anders , Bladström Anna , Their Mark , Nordenström Erik , Valdemarsson Stig , Westerdahl Johan
Published: May 2007

Background

Primary hyperparathyroidism (pHPT) is associated with an increased mortality attributable to cardiovascular disease (CVD), suggested to be alleviated by surgery. The exact mechanism of the beneficial influence of parathyroidectomy on survival is unknown. Furthermore, studies suggest that there is no increased mortality compared to the mortality rate in the general population during recent years. This study therefore investigated relative survival (RS), as well overall mortality associated with the clinical and biochemical variables in patients undergoing operation for sporadic pHPT. Furthermore, the influence of surgery on biochemical variables associated with pHPT was analyzed.

Methods

A group of 323 patients with sporadic pHPT operated between September 1989 and July 2003 were followed from surgery over a 10‐year period. The median and mean follow‐up time was 69 and 70 months, respectively (range: 1–120 months). Relative survival (RS) was calculated, and the impact of clinical and biochemical variables on overall death were evaluated.

Results

Postoperatively, serum levels of triglycerides and uric acid decreased. Glucose levels and glomerular filtration rate remained unchanged. A decreased RS was evident during the latter part of the 10 year follow‐up period. In the multivariate Cox‐analysis, diabetes mellitus (hazard ratio [HR] = 2.8, 95%; confidence interval [CI] 1.2–6.7), and the combination of an increased level of serum uric acid and cardiovascular disease (CVD) (HR = 8.6, 95%; CI 1.5–49.7) was associated with a higher mortality. The increased risk of death was evident for patients with persistently increased levels of uric acid postoperatively (HR = 4.8, 95%; CI = 1.4–16.01)

Conclusions

Patients undergoing operation for pHPT had a decreased RS during a 10‐year follow‐up compared to the general population. This decrease in RS is associated with diabetes mellitus and increased levels of uric acid pre‐and postoperatively.
The Influence of High Serum Testosterone Levels on the Long‐term Prognosis in Male Patients Undergoing Hepatectomy for Early Stage Hepatocellular Carcinoma without Vascular Invasion
Authors: Lin Min‐Che , Wu Cheng‐Chung , Cheng Shao‐Bin , Liu Tse‐Jia , P’eng Fang‐Ku
Published: May 2007

Background

The influence of high serum testosterone levels on the long‐term prognosis in male patients undergoing hepatectomy for hepatocellular carcinoma (HCC) remains to be fully elucidated. The aim of the present study was to conduct a retrospective investigation of the impact of high serum testosterone levels on the risk of tumor recurrence and long‐term prognosis in male patients undergoing hepatectomy for early stage HCC without vascular invasion.

Methods

Between August 1995 and March 1999, 42 male patients undergoing curative hepatectomy for HCC of tumor‐node‐metastasis (TNM) stages I and II without vascular invasion were enrolled in the study. Preoperative serum testosterone concentration was measured. The clinicopathological features, tumor recurrence rates, and 5‐year disease‐free and actuarial survival after hepatectomy were compared between the patients with serum testosterone levels in the upper half (group I, n = 21) and the patients in the lower half (group II, n = 21).

Results

The background and clinicopathological features did not differ significantly between groups I and group II. All survivors were followed up for more than 5 years. Until March 2005, patients in group I, with serum testosterone levels in the upper half, had a significantly higher percentage of 5‐year tumor recurrence than group II, with lower testosterone levels (76.2% versus 28.6%; p < 0.005). The patients in group I also had a significantly inferior 5‐year disease‐free (p < 0.01) and actuarial (p < 0.05) survival rates than patients in group II.

Conclusions

Male patients with high serum testosterone levels undergoing hepatectomy for early stage HCC without vascular invasion have significantly higher 5‐year tumor recurrence rates and an inferior long‐term prognosis than patients with low testosterone levels. These findings signal a strategy of adjuvant anti‐androgen treatment selectively targeted for the male patients with high serum testosterone levels after hepatectomy for early stage HCC without vascular invasion to achieve better long‐term outcome.
Inhibition of oxidation in 10% oil‐in‐water emulsions by β‐carotene with α‐ and γ‐tocopherols
Authors: Heinonen Marina , Haila Katri , Lampi Anna‐Maija , Piironen Vieno
Published: May 2007

The effects of low concentrations of β‐carotene, α‐, and γ‐tocopherol were evaluated on autoxidation of 10% oil‐in‐water emulsions of rapeseed oil triacylglycerols. At concentrations of 0.45, 2, and 20 µg/g, β‐carotene was a prooxidant, based on the formation of lipid hydroperoxides, hexanal, or 2‐heptenal. In this emulsion, 1.5, 3, and 30 µg/g of γ‐tocopherol, as well as 1.5 µg/g of α‐tocopherol, acted as antioxidants and inhibited both the formation and decomposition of lipid hydroperoxides. Moreover, at a level of 1.5 µg/g, γ‐tocopherol was more effective as an antioxidant than α‐tocopherol. At levels of 0.5 µg/g, both α‐ and γ‐tocopherol significantly inhibited the formation of hexanal but not the formation of lipid hydroperoxides. Oxidation was effectively retarded by combinations of 2 µg/g β‐carotene and 1.5 µg/g γ‐ or α‐tocopherol. The combination of β‐carotene and α‐tocopherol was significantly better in retarding oxidation than α‐tocopherol alone. While γ‐tocopherol was an effective antioxidant, a synergistic effect between β‐carotene and γ‐tocopherol could not be shown. The results indicate that there is a need to protect β‐carotene from oxidative destruction by employing antioxidants, such as α‐ and γ‐tocopherol, should β‐carotene be used in fat emulsions.
Consumption of cholesterol oxides from fast foods fried in beef fat in New Zealand
Authors: Lake R. J. , Scholes P.
Published: May 2007

Levels of cholesterol oxides were determined in samples of beef dripping used for deep frying in retail fast‐food outlets in Christchurch, New Zealand. The average levels (n = 8) of cholesterol oxides were: β‐epoxy cholesterol (15 mg/kg), α‐epoxy cholesterol, 7β‐hydroxy cholesterol, 7‐keto cholesterol (10 mg/kg each), 7α‐hydroxy cholesterol (5 mg/kg), and cholestane triol, 25‐hydroxy cholesterol (1 mg/kg each). Based on the amount of fat in a typical deep‐fried “fish and chips” meal, the amounts of individual cholesterol oxides consumed would then range from 0.05–0.7 mg. This is three to nine times less than reported in a test meal experiment with humans but could still be expected to cause detectable increases in plasma cholesterol oxide levels.
Isomerization of α‐pinene to camphene
Authors: Findik S. , Gündüz G.
Published: May 2007

The catalytic isomerization reaction of α‐pinene to camphene over a clinoptilolite catalyst was investigated in a batch reactor open to the atmosphere between 130 and 155°C. The catalyst was selective to the isomerization of α‐pinene to camphene. The effects of several variables, such as reaction temperature, amount of catalyst, stirring speed and catalyst particle size, on the conversion of α‐pinene and selectivity to camphene were determined. The reaction fits a first‐order parallel reaction with rate constants of k1 = 3.020·10−2e−33381.6/RT for the production of camphene and of k2 = 1.576·10−2e−31096.53/RT for the production of limonene.
Relationship between seed mass and linolenic acid in progeny of crosses between cultivated and wild soybean
Authors: Pantalone V. R. , Rebetzke G. J. , Wilson R. F. , Burton J. W.
Published: May 2007

Soybean [Glycine max (L.) Merr.] oil from current commercial cultivars typically contains ca. 8% linolenic acid (18:3). Applications of plant biotechnology have enabled plant breeders to develop germplasm having as low as 2.0% 18:3. Oils that are naturally low in 18:3 exhibited improved flavor characteristics and greater oxidative stability in high‐temperature frying applications compared to hydrogenated soybean oil. As an extension of that research, efforts are underway to characterize genes in soybean that govern expression of higher than normal 18:3 concentration. Such oils may be of interest to the oleochemicals industry for various nonfood applications. Relatively high 18:3 in seed oil is a characteristic trait of the ancestor of modern soybean cultivars, Glycine soja (Sieb. and Zucc.). Accessions of this species have rarely been utilized in soybean improvement, and thus represent a virtually untapped genetic resource for genes governing 18:3 synthesis. We have hybridized cultivated soybean with wild soybean plant introductions. F3:4 seed from the resultant G. max × G. soja populations exhibited a wide segregation pattern for 18:3 and seed mass. A strong negative association was found between 18:3 concentration and seed mass. Oil concentration was positively correlated with seed mass. Evaluation of glycerolipid composition revealed that high 18:3 was not associated with an altered proportion of phospholipid and triacylglycerol among lines segregating for seed mass. Thus, smaller seed mass may be a convenient trait to distinguish future soybean cultivars with highly polyunsaturated oils from other cultivars in production.
Utilization of high‐melting palm stearin in lipase‐catalyzed interesterification with liquid oils
Authors: Ghosh S. , Bhattacharyya D. K.
Published: May 2007

Palm stearin with a melting point (m.p.) of 49.8°C was fractionated from acetone to produce a low‐melting palm stearin (m.p.=35°C) and a higher‐melting palm stearin (HMPS, m.p.=58°C) fraction. HMPS was modified by interesterification with 60% (by weight) of individual liquid oils from sunflower, soybean, and rice bran by means of Mucor miehei lipase. The interesterified products were evaluated for m.p., solid fat content, and carbon number glyceride composition. When HMPS was interesterified individually with sunflower, soybean or rice bran at the 60% level, the m.p. of the interesterified products were 37.5, 38.9, and 39.6°C, respectively. The solid fat content of the interesterified products were 30–35 at 10°C, 17–19 at 20°C, and 6–10 at 30°C, respectively. The carbon number glyceride compositions also changed significantly. C48 and C54 glycerides decreased remarkably with a corresponding increase of the C50 and C52 glycerides. All these interesterified products were suitable for use as trans acid‐free and polyunsaturated fatty acid‐rich shortening and margarine fat bases.
Medium‐chain fatty acid‐rich glycerides by chemical and lipase‐catalyzed polyester‐monoester interchange reaction
Authors: Ghosh S. , Bhattacharyya D. K.
Published: May 2007

Medium‐chain triglycerides (MCT) that contain caprylic acid (C8:0) and capric acid (C10:0) have immense medicinal and nutritional importance. Coconut oil can be used as a starting raw material for the production of MCT. The process, based on the interchange reaction between triglycerides and methyl esters of medium‐chain fatty acids by chemical catalyst (sodium methoxide) or lipase (Mucor miehei) catalyst, appears to be technically feasible. Coconut oils with 25–28.3% (w/w) and 22.1–25% (w/w) medium‐chain fatty acids have been obtained by chemical and lipase‐catalyzed interchange reactions. Coconut olein has also been modified with C8:0 and C10:0 fatty acids, individually as well as with their mixtures, by chemical and lipase‐catalyzed interchange reactions. Coconut olein is a better raw material than coconut oil for production of mediumchain fatty acid‐rich triglyceride products by both chemical and lipase‐catalyzed processes.
Δ5‐olefinic acids in the edible seeds of nut pines (Pinus cembroides edulis) from the United States
Authors: Wolff Robert L. , Marpeau Anne M.
Published: May 2007

The fatty acid composition of the edible seeds from Pinus cembroides edulis (a nut pine), that might have been a commercial source of Δ5‐olefinic acids in the United States, has been established. The dehulled seeds are rich in oil (64% by weight) and are characterized by high levels of both oleic and linoleic acids (ca. 47 and 41%, respectively), with only 10% of saturated acids. Δ5‐Olefinic acids, which were not reported previously in this species, are exceptionally low as compared to most other conifer species: 5,9‐18:2 acid, 0.1%; 5,9,12‐18:3 acid, 0.4%; 5, 11, 14‐20:3 acid, 0.3%. In this respect, P. cembroides edulis seed oil closely resembles that of P. pinea (a circum‐Mediterranean species), which emphasizes the morphological and taxonomic relationship between the sections to which the two species belong (Parryana and Pinea, respectively).
The magnetic field as an additional selectivity parameter in fat hydrogenation
Authors: Jart Aage
Published: May 2007

An investigation of the influence of a magnetic field on selectivity ratios (SR) in the nickel‐catalyzed hydrogenation process of fats is presented. Sesame oil and soybean oil were hydrogenated in an AC field of 300 oersted. The SR SR=K2/K3 and linolenic SR=K1/K2 obtained were higher than those without a field because the magnetization of the nickel particles reduced the concentration of hydrogen on the catalyst surface.
Synthesis of 6‐hydroxy δ‐lactones and 5,6‐dihydroxy eicosanoic/docosanoic acids from meadowfoam fatty acids via a lipase‐mediated self‐epoxidation
Authors: Frykman Hans B. , Isbell Terry A.
Published: May 2007

Meadowfoam fatty acids were reacted with hydrogen peroxide in a lipase‐catalyzed autocatalytic system, forming a mixture of 5,6‐epoxyeicosanoic, 13,14‐epoxydocosanoic, 5,6‐epoxydocosanoic, and 5,6‐13,14‐diepoxydocosanoic acids in 98% yield. The 5,6‐epoxy acids were cyclized to 6‐hydroxy δ‐eicosanoic/docosanoic lactones by sulfuric acid catalysis in high yield (99%). 5,6‐Dihydroxy acids could be obtained from 6‐hydroxy δ‐lactones by a simple alkaline work‐up procedure. Meadowfoam fatty acids were converted (77% yield) in a one‐pot reaction to 6‐hydroxy δ‐lactones by in situ performic acid epoxidation and subsequent addition of sulfuric acid.
Identification of cyclopentenyl fatty acids by1H and13C nuclear magnetic resonance
Authors: Blaise Pierre , Farines Marie , Soulier Jacques
Published: May 2007

Gorlic, chaulmoogric and hydnocarpic fatty acids, specific to the seed oil of the genusHydnocarpussp. (Flacourtiaceae), are determined only with difficulty by gas chromatography. These fatty acids were isolated in their methyl ester form by a combination of different chromatographic techniques (thin‐layer chromatography/Ag+and high‐pressure liquid chromatography). The proton and carbon nuclear magnetic resonance analysis of these fatty acid methyl esters showed some characteristic signals of the cyclopentenyl ring. The presence of these signals in the proton and/or carbon nuclear magnetic resonance spectrum of an oil thus will allow us to confirm the presence of these cyclopentenyl fatty acids in lipids.
Antioxidant efficacy of methanolic extracts of peanut hulls in soybean and peanut oils
Authors: Duh Pin‐Der , Yen Gow‐Chin
Published: May 2007

Antioxidant activity of methanolic extracts of peanut hulls (MEPH) was evaluated in soybean and peanut oils after accelerated oxidation at 60°C. Results showed that the oils with 0.12, 0.48, and 1.20% MEPH had significantly (P<0.05) lower peroxide values and acid values than the control after storage at 60°C. Moreover, oils with 0.48 and 1.20% MEPH were significantly (P<0.05) superior to 0.02% butylated hydroxyanisole (BHA) in reducing oxidation of both oils. Negative synergism was observed when 0.48 and 1.20% MEPH were mixed with 0.01% dl‐α‐tocopherol or 0.01% BHA in soybean oil compared to MEPH alone.
Experimental characterization of emulsion formation and coalescence by nuclear magnetic resonance restricted diffusion techniques
Authors: Lee H.‐Y. , McCarthy M. J. , Dungan S. R.
Published: May 2007

Nuclear magnetic resonance (NMR) is explored as a technique for noninvasively monitoring emulsion droplet formation and destabilization. The method makes use of the fact that the diffusion of oil molecules within oil‐in‐water emulsion droplets results in attenuation of a coherent magnetic signal that emanates from those molecules. If oil diffusion is limited by the size of the droplet, the shape of a plot of attenuation over time is directly affected by the droplet radius. We use this approach to determine noninvasively the effect of surfactant type, surfactant concentration, pH, and ionic strength on droplet sizes within a 40 wt% octane and water emulsion, stabilized by Tween 20 or β‐lactoglobulin (β‐Lg). We find that addition of the low‐molecular‐weight Tween 20 forms finer emulsion droplets than does addition of the protein, and that the Tween 20 emulsion is sensitive to surfactant concentration below a threshold “saturation” concentration. The droplet sizes in β‐Lg‐containing emulsions increase as pH increases above the isoelectric point and as ionic strength increases. The fact that the NMR technique does not mistake clusters of droplets for single large droplets makes the analysis of these effects unambiguous. We further extend the use of NMR diffusion techniques to monitor the effect of surfactant type, surfactant concentration, and convection on the rate of droplet coalescence. The ability of NMR methods to distinguish between large single droplets and droplet clusters makes it well‐suited to monitor coalescence processes independently from flocculation.
Lipid and fatty acid biosynthesis by Rhodotorula minuta
Authors: Saxena Vani , Sharma C. D. , Bhagat S. D. , Saini V. S. , Adhikari D. K.
Published: May 2007

Demand for fatty acids is increasing at an annual rate of 17%, due to their increased use in the oleochemical and transport industries. Presently, vegetable oils are the major source of fatty acids, whereas lipids with fatty acids similar to those of some vegetable oils have been reported to be synthesized by oleaginous microorganisms. In the present study, the culturing conditions for the oleaginous yeast Rhodotorula minuta IIP‐33 have been optimized. In contrast to the lipid accumulation characteristics of most oleaginous yeasts, a carbon‐to‐nitrogen ratio of 30 was favorable for maximal accumulation of lipids (48%) with 22.5% conversion of glucose as carbon substrate. The lipids contained fatty acids in the C7–C18 range, the relative composition of which varied with culture temperature.
In Vitro hydrolysis of fungal oils: Distribution of arachidonic acid‐containing triacylglycerol molecular species
Authors: Liu Jim‐Wen , Bobik Emi G. , Huang Yung‐Sheng
Published: May 2007

Four commercially prepared arachidonic acidrich oils from the fungus Mortierella alpina were analyzed by high‐performance liquid chromatography and gas chromatography. The levels of arachidonic acid and the distribution of triacylglycerol (TG) molecular species varied significantly among these oils. The major arachidonate‐containing TG species were AAA, LAA, DAA, OAA, PAA, SAA, OLA, PGA, PLA, POA, and SOA where the abbreviations A, D, G, L, O, P, and S represent arachidonic (20:4n‐6), dihomo‐γ‐linolenic (20:3n‐6), γ‐linolenic (18:3n‐6), linoleic (18:2n‐6), oleic (18:1n‐9), palmitic (16:0), and stearic (18:0) acids, respectively. In vitro incubation of the TG fractions, purified from these oils with porcine pancreatic lipase for 5 min, yields a mixture of intermediate products, such as 1,2‐ and 2,3‐diacylglycerols (1,2‐ and 2,3‐DG), 2‐monoacylglycerol (2‐MG) and free fatty acids (FFA), as well as residual TG. The degrees of hydrolysis varied significantly among the four oil preparations, ranging from 35 to 57%. The levels of arachidonic acid in the residual TG and 1,2(2,3)‐DG were significantly higher than those in the original TG, whereas those in the FFA fraction were significantly lower than those in 1,2(2,3)‐DG and 2‐MG. Results from this study suggest that the bioavailability of arachidonic acid differs among fungal oils prepared by different suppliers. These differences could be attributed to the arachidonic acid content of the oil as well as to the association of arachidonic acid with other fatty acids in the same TG molecule.
Screening catalytic lipase activities with an analytical supercritical fluid extractor
Authors: Frykman Hans B. , Snyder Janet M. , King Jerry W.
Published: May 2007

Two different screenings of several commercial lipases were performed to find a lipase with superior performance for the conversion of lipid moieties to their fatty acid methyl ester (FAME) derivatives under supercritical conditions. The first screening was done under hydrolytic conditions in a buffer. The second screening was done under supercritical conditions with CO2, utilizing some of the same lipases for the methanolysis of different lipids. For the substrates studied, there was a significant difference in lipase activity under the two above conditions. Significant hydrolytic activity was demonstrated for three different lipid types (triglycerides, sterols, and phospholipids) with Lipase PS30, but when the same lipase was immobilized on an Accurel carrier (polypropylene), the activity decreased considerably. The opposite was found for Lipase G, which showed strong activity when immobilized and under supercritical conditions. Furthermore, Chirozyme L‐1 was superior under supercritical conditions. The altered substrate specificity that some of these lipases show in supercritical CO2 suggests several interesting synthetic options and applications under these conditions.
Functionalization at the double‐bond region of jojoba oil. 9. solid‐state nuclear magnetic resonance characterization of substituted jojoba wax chemically bonded to a polystyrene matrix
Authors: Binman Sofia , Vega Shimon , Belfer Sofia , Shani Arnon
Published: May 2007

Solid extractants for metal ions have been prepared by chemical bonding of jojoba wax to a polystyrene backbone, followed by phosphonation or sulfur‐chlorination of the jojoba moiety. In this study, the intermediates and final solid products of the reactions were characterized by solid‐state 13C and 31P nuclear magnetic resonance spectroscopy. The spectra showed the expected chemical shifts of the atoms involved in the chemical reactions, as well as other parts of the reacting molecules. Thus, the carbonyl carbon of the jojoba chain appears at 175 ppm, the methyl carbons at 15 ppm, the polystyrene backbone at 40–42 ppm (aliphatic carbons) and 128, 137, 143–147 (aromatic carbons). Carbons adjacent to N, S, and P appear at 45–55, 60, and 48 ppm, respectively.
Remarks on official methods employing boron trifluoride in the preparation of methyl esters of the fatty acids of fish oils
Authors: Ackman R. G.
Published: May 2007

Some “official methods” for preparing methyl esters of the fatty acids from oils or fats may be referred to by users as the boron trifluoride (BF3) method and invariably have two stages. The first stage, brief treatment with alkali [commonly NaOH in methanol (MeOH), sometimes NaOCH3] and heat has been popularly described as a saponification step for over 30 yr. In fact, the disappearance of visible fat or oil is mostly transesterification, which can be accomplished in a few minutes under mild conditions. Free fatty acids (FFA) originally present, or produced by saponification, are not converted to methyl esters at this stage. The second stage, heating in BF3‐MeOH, has in practice been as short as 2 min. It can convert all FFA to methyl esters, but this step requires at least 30 min. Examples from the recent literature illustrate the necessity of extending the time for BF3‐MeOH transesterification of lipids or oils and methylation of FFA. No alkali transesterification is needed.
Dietary patterns in infancy: the importance of maternal and family influences on feeding practice
Authors: Robinson Siân , Marriott Lynne , Poole Jason , Crozier Sarah , Borland Sharon , Lawrence Wendy , Law Catherine , Godfrey Keith , Cooper Cyrus , Inskip Hazel ,   The Southampton Women's Survey Study Group
Published: May 2007

It is not known what constitutes an optimal diet in infancy. There are relatively few studies of weaning practice in the UK, and there is a need for prospective data on the effects of infant diet and nutrition on health in later life. We describe the dietary patterns, defined using principal components analysis of FFQ data, of 1434 infants aged 6 and 12 months, born between 1999 and 2003. The two most important dietary patterns identified at 6 and 12 months were very similar. The first pattern was characterised by high consumption of fruit, vegetables and home-prepared foods (‘infant guidelines’ pattern). The second pattern was characterised by high consumption of bread, savoury snacks, biscuits and chips (‘adult foods’ pattern). Dietary pattern scores were correlated at 6 and 12 months (r0·46 ‘infant guidelines’;r0·45 ‘adult foods’). These patterns, which reflect wide variations in weaning practice, are associated with maternal and family characteristics. A key influence on the infant diet is the quality of the maternal diet. Women who comply with dietary recommendations, and who have high intakes of fruit and vegetables, wholemeal bread and rice and pasta, are more likely to have infants who have comparable diets – with high ‘infant guidelines’ pattern scores. Conversely, women whose own diets are characterised by high intakes of chips, white bread, crisps and sweets are more likely to have infants who have high ‘adult foods’ pattern scores. The effects of these patterns on growth and development, and on long-term outcomes need to be investigated.
Naturalistic follow-up of co-morbid substance use in schizophrenia: the West London first-episode study
Authors: Harrison I. , Joyce E. M. , Mutsatsa S. H. , Hutton S. B. , Huddy V. , Kapasi M. , Barnes T. R. E.
Published: May 2007

Background

The impact of co-morbid substance use in first-episode schizophrenia has not been fully explored.

Method

This naturalistic follow-up of a cohort of 152 people with first-episode schizophrenia examined substance use and clinical outcome in terms of symptoms and social and neuropsychological function.

Results

Data were collected on 85 (56%) of the patient cohort after a median period of 14 months. Over the follow-up period, the proportion of smokers rose from 60% at baseline to 64%. While 30% reported lifetime problem drinking of alcohol at baseline, only 15% had problem drinking at follow-up. Furthermore, while at baseline 63% reported lifetime cannabis use and 32% were currently using the drug, by the follow-up assessment the latter figure had fallen to 18.5%. At follow-up, persistent substance users had significantly more severe positive and depressive symptoms and greater overall severity of illness. A report of no lifetime substance use at baseline was associated with greater improvement in spatial working memory (SWM) at follow-up.

Conclusions

Past substance use may impede recovery of SWM performance in people with schizophrenia in the year or so following first presentation to psychiatric services. The prevalence of substance use other than tobacco tends to diminish over this period, in the absence of specific interventions. Persistent substance use in first-episode schizophrenia is associated with more severe positive and depressive symptoms but not negative symptoms, and should be a target for specific treatment intervention.
A new approach to the fight against desertification in Inner Mongolia
Authors: LI GANG , JIANG GAOMING , LI YONGGENG , LIU MEIZHEN , PENG YU , LI LINGHAO , HAN XINGGUO
Published: May 2007

The world's arid and semi-arid regions are severely affected by desertification. In China, wind erosion, water erosion, soil salinization and the freezing and melting processes have contributed to 2.64 million km2 of desertified land, covering 27.5% of the country's land surface (State Forestry Administration, Peoples' Republic of China 2005). Although climate change could be a reason for desertification, anthropogenic factors such as overgrazing and overcultivation also contribute to degradation in grassland areas (Millennium Ecosystem Assessment 2005; Zheng et al. 2006). The Chinese government has adopted afforestation as the main measure to control desertification. Major projects, including the ‘Three North Shelterbelt Programme’ (also known as the ‘Green Great Wall’) and the ‘Sandstorm Source Control Project around Beijing and Tianjin’, are necessary to shield northern and eastern agricultural ecosystems against sand and dust (Zhou 2002). However, these countermeasures require substantial effort and investment, and, in the semi-arid and arid regions of Inner Mongolia, newly planted trees have often died of drought, while tree planting could also be responsible for exhausting the precious groundwater resources of these regions (Jackson et al. 2005). Alternative and more practical ways of combating desertification by using multi-disciplinary approaches observing both social and ecological principles are required. The Hunshandake Sandy Land restoration demonstration project conducted by the Chinese Academy of Sciences was an attempt to restore desertified grassland mainly through natural processes, and requiring limited investment.
Freely draining gravity currents in porous media: Dipole self-similar solutions with and without capillary retention
Authors: MATHUNJWA JOCHONIA S. , HOGG ANDREW J.
Published: May 2007

We analyse the two-dimensional, gravitationally-driven spreading of fluid through a porous medium overlying a horizontal impermeable boundary from which fluid can drain freely at one end. Under the assumption that none of the intruding fluid is retained within the pores in the trail of the current, the motion of the current is described by the dipole self-similar solution of the first kind derived by Barenblatt and Zel'dovich (1957). We show that small perturbations of arbitrary shape imposed on this solution decay in time, indicating that the self-similar solution is linearly stable. We use the connection between the perturbation eigenfunctions and symmetry transformations of the self-similar solution to demonstrate that variables can always be specified in terms of which the rate of decay of the perturbations is maximised. Unsaturated flow can be modelled by assuming that a constant fraction of the fluid is retained within the pores by capillary action in the trail of the current. It has been shown (Barenblatt and Zel'dovich, 1998; Ingerman and Shvets, 1999) that in this case, the motion of the current is described by a self-similar solution of the second kind characterised by an anomalous exponent. We derive leading-order analytic expressions for the anomalous exponent and the self-similar quantities valid for small values of the fraction of fluid retained using direct asymptotic analysis and by using a novel application of the method of multiple scales. The latter offers a number of advantages and permits the evolution of the current to be clearly connected with its initial conditions in a way not possible with conventional approaches. We demonstrate that the theoretical predictions provided by these expressions are in excellent agreement with results from the numerical integration of the governing equations.
Averaging of flows with capillary hysteresis in stochastic porous media
Authors: SCHWEIZER BEN
Published: May 2007

Fluids in unsaturated porous media are described by the relationship between pressure (p) and saturation (u). Darcy's law and conservation of mass provides an evolution equation for u, and the capillary pressure provides a relation between p and u of the form p∈ pc(u,∂tu). The multi-valued function pc leads to hysteresis effects. We construct weak and strong solutions to the hysteresis system and homogenize the system for oscillatory stochastic coefficients. The effective equations contain a new dependent variable that encodes the history of the wetting process and provide a better description of the physical system.
Population status and distribution of Taita White-eye Zosterops silvanus in the fragmented forests of Taita Hills and Mount Kasigau, Kenya
Authors: Mulwa Ronald K , Bennun Leon A , Ogol Callistus K. P. O. , Lens Luc
Published: May 2007

Our study focused on the Taita White-eye Zosterops silvanus, one of three bird species endemic to the Taita Hill forests, south-east Kenya. Formerly considered Critically Endangered, Taita White-eye has been down-listed to Endangered following the findings of this study. Between November 1998 and September 1999 we counted this species along line transects to establish their current population status and distribution in its entire range. White-eye censuses were conducted in nine forest fragments of the Taita Hills and the virtually undisturbed Mt Kasigau forest. The total global population of Taita White-eyes was estimated to be c. 7,100 birds. Mt Kasigau was shown to be the species' main stronghold, maintaining a very high density (26 birds ha−1) and holding 80% (5,600 individuals) of the entire population. In the Taita Hills forests, densities were consistently higher in the small isolated fragments than in the large ones, though the former held only a small population (3% of total). At Mt Sagala, a large isolated block where indigenous trees have been largely replaced with exotic plantation, this species was not encountered. We found no evidence of interchange between the White-eye populations on Mt Kasigau and the Taita Hills forests, probably because of the separation by a low-altitude, dry woodland habitat barrier. While prioritization for conservation action should focus more on the Taita Hills forest fragments, Mt Kasigau should be treated as fragile ecosystem which holds a huge, apparently insular population of Taita White-eyes.
Conservation Status of the Chilean Woodstar Eulidia yarrellii
Authors: Estades Cristián F. , Aguirre Juan , Escobar Martín A. H. , Tomasevic Jorge A. , Vukasovic María Angélica , Tala Charif
Published: May 2007

We assessed the conservation status of the Chilean Woodstar Eulidia yarrellii, a small hummingbird endemic to a few desert valleys of northern Chile and southern Peru. Although no population studies had been conducted, this rare species was presumed to have undergone a severe population decline during the past decades. Fieldwork in Chile produced a population estimate for September 2003 of 1,539 individuals (929–2,287; 90% CI), located in just two valleys: Azapa and Vitor. There was no evidence of stable populations elsewhere. Our observations tend to confirm the hypothesis of a past decline and evidence points to three main factors driving that trend: (1) Most natural habitat has disappeared and the species relies mostly on artificial resources for feeding and nesting. (2) The start of heavy use of pesticides in the Azapa valley in the 1960s in order to control the Mediterranean fruit fly and other crop pests coincides with the last reports describing the species as abundant. (3) The irruption in the last two decades of the Peruvian Sheartail Thaumastura cora has apparently exerted serious competition pressure on the species. These findings support the classification of the species as globally Endangered. We describe the main lines of action of the recently approved Recovery Plan for the Chilean Woodstar.
Geomagnetic field modeling from satellite attitude control magnetometer measurements
Authors: Kim Jeong Woo , Hwang Jong Sun , von Frese Ralph R. B. , Kim Hyung Rae , Lee Seon‐Ho
Published: May 2007

To demonstrate the utility of satellite attitude control magnetometer measurements for mapping main field variations, we analyzed the three‐axis magnetometer (TAM) measurements that provide attitude control for the KOMPSAT‐1 satellite. Initial processing involved transforming the TAM's magnetic measurements from the Earth‐Centered Inertial coordinates (ECI) to the Earth‐Centered Earth‐Fixed coordinates (ECEF) and then to spherical coordinates. The magnetic field of the satellite body produces symmetric signatures in the ascending and descending orbital measurements and thus can be readily removed. Spectral correlation filtering of the orbital observations helped to eliminate the dynamic external field and solar activity noise components. The ascending and descending data were then spectrally reconstructed to estimate the total magnetic field with minimum track line noise. Correlation coefficients of 0.97 and 0.96 mark the correlation of the KOMPSAT‐1 total geomagnetic intensity map with the Ørsted and IGRF2000 core magnetic field models, respectively. Power spectra from Gauss coefficients of KOMPSAT‐1 model showed closeness with the models from Ørsted data and IGRF2000 model. The spherical harmonic coefficients calculated from the KOMPSAT‐1 model by conjugate gradient inversion are strongly coherent with the Ørsted and IGRF2000 coefficients through degree 9.
Quantitative bedrock geology of Brazil
Authors: Peucker‐Ehrenbrink Bernhard , Miller Mark W.
Published: May 2007

We quantitatively analyze the area‐age distribution of sedimentary, igneous, metamorphic, and ultramafic bedrock on the basis of data from the digital geologic map of Brazil, published as a GIS map by the Brazilian Geological Survey. Bedrock units exclusively encompassing sedimentary rocks, igneous rocks, or metamorphic rocks cover 40.4%, 31.5%, and 17.7%, respectively, of the total bedrock area. These numbers have to be considered minimum estimates of the areal abundance of sedimentary, igneous, and metamorphic bedrock because polygons defined by mixed lithologies cover ∼8.5–9.5% of the total bedrock area. These mixed units are sedimentary rocks with igneous and/or metamorphic contributions (1.4%), metamorphic rocks with sedimentary contributions (1.2%), metamorphic rocks with igneous contributions (1.5%), igneous rocks with sedimentary and/or metamorphic contributions (4.4%), and ultramafic units with sedimentary, igneous, and/or metamorphic contributions (∼1–2%). The average ages of major lithologic units, weighted according to bedrock area, are as follows: sedimentary rocks (average stratigraphic age of 248 ± 5 [1σ] Myr; median stratigraphic age of 87.5 Myr), igneous rocks (1153 ± 13 [1σ] Myr), metamorphic rocks (1678 ± 30 [1σ] Myr), and ultramafic rocks (∼1227 ± 25 [1σ] Myr). The average bedrock age of Brazil is 946 ± 7 [1σ] Myr. The range in lithologic composition and age structure of the various bedrock units reflects the complex tectonic makeup of Brazil that ranges from Neogene sedimentary cover in the Amazon Basin to Precambrian cratons (Guyana and Brazilian shields) and Transamazonian greenstone belts. The average spatial resolution of the data is 232 km2 polygon−1 and is sufficient to perform area‐age analyses of individual river drainage basins larger than ∼5,000 km2.
Comparative study of Geomagnetic Sudden Commencement (SC) between Oersted and ground observations at different local times
Authors: Han De‐Sheng , Araki T. , Yang H.‐G. , Chen Z.‐T. , Iyemori T. , Stauning P.
Published: May 2007

Oersted is a low‐altitude (638–849 km) polar‐orbiting satellite. Using vector magnetic field measurements obtained from Oersted, we identified more than 20 geomagnetic sudden commencement (SC) events on both dayside (0600–1800 MLT) and nightside (1800–0600 MLT). The unique properties reflected by these events have never been reported before. The SCs observed by Oersted in the B// (compressional) component on the nightside had the nearly same waveforms as those observed on the ground in the H (northward) component. We suggest that the SCs observed by Oersted on the nightside were dominantly caused by the enhanced magnetopause currents, which were transmitted by the compressional hydromagnetic waves, and the effects of the ionospheric current (IC) were negligible on the nightside. The SC waveforms observed by Oersted on the dayside were apparently different from those observed on the ground. Near the dayside dip equator (DDE), corresponding to preliminary reverse impulses (PRIs) observed in the ground H component, Oersted always observed positive impulses in the B// component, which suggest that the PRIs at the DDE are generated by westward ICs. On the dayside, corresponding to positive main impulses (MIs) of SCs observed in the ground H component, the Oersted B// component always presented clear decreases, which implies that an eastward IC was excited after the PRI. The generation mechanism for the westward and eastward ICs are discussed according to previously proposed models. On the dayside, we suggest that the waveforms observed both on the ground and at Oersted during the time period of PRI and MI were superposition of the incident compressional waves and the disturbance fields caused by the ICs. The features observed by Oersted just above the ionosphere are significant complementary to our empirical knowledge for SCs.
Application of rate‐and‐state friction laws to creep compaction of unconsolidated sand under hydrostatic loading conditions
Authors: Hagin Paul , Sleep Norman H. , Zoback Mark D.
Published: May 2007

Rate‐and‐state variable friction laws describe the time‐dependent fault‐normal compaction that occurs during holds in slide‐hold‐slide friction tests on unconsolidated materials. This time‐dependent deformation is qualitatively similar to that observed during volumetric creep strain tests on unconsolidated sands and shales under hydrostatic loading conditions. To test whether rate‐and‐state friction laws can be used to model volumetric creep processes in unconsolidated sands, the rate‐and‐state formulation is expanded to include deformation under hydrostatic stress boundary conditions. Results show that the hydrostatic stress form of the rate‐and‐state friction law successfully describes the creep strain of unconsolidated sand. More importantly, values obtained for rate‐and‐state friction parameters by fitting these data are in the same range as those obtained from more traditional tests by fitting the fault‐normal compaction of simulated gouge during a hold in a laboratory friction experiment.
Tropospheric phase delay in interferometric synthetic aperture radar estimated from meteorological model and multispectral imagery
Authors: Puysségur Béatrice , Michel Rémi , Avouac Jean‐Philippe
Published: May 2007

ENVISAT Medium Resolution Imaging Spectrometer Instrument (MERIS) multispectral data and the mesoscale meteorological model MM5 are used to estimate the tropospheric phase delay in synthetic aperture radar (SAR) interferograms. MERIS images acquired simultaneously with ENVISAT Advanced Synthetic Aperture Radar data provide an estimate of the total water vapor content W limited to cloud‐free areas based on spectral bands ratio (accuracy 0.17 g cm−2 and ground resolution 300 m). Maps of atmospheric delay, 2 km in ground resolution, are simulated from MM5. A priori pertinent cumulus parameterization and planetary boundary layer options of MM5 yield near‐equal phase correction efficiency. Atmospheric delay derived from MM5 is merged with available MERIS W product. Estimates of W measured from MERIS and modeled from MM5 are shown to be consistent and unbiased and differ by ∼0.2 g cm−2 (RMS). We test the approach on data over the Lebanese ranges where active tectonics might contribute to a measurable SAR signal that is obscured by atmospheric effects. Local low‐amplitude (1 rad) atmospheric oscillations with a 2.25 km wavelength on the interferograms are recovered from MERIS with an accuracy of 0.44 rad or 0.03 g cm−2. MERIS water product overestimates W in the clouds shadow due to mismodeling of multiple scattering and underestimates W on pixels with undetected semitransparent clouds. The proposed atmospheric filter models dynamic atmospheric signal which cannot be recovered by previous filtering techniques which are based on a static atmospheric correction. Analysis of filter efficiency with spatial wavelength shows that ∼43% of the atmospheric signal is removed at all wavelengths.
Plate kinematic evidence for the existence of a distinct plate between the Nubian and Somalian plates along the Southwest Indian Ridge
Authors: Horner‐Johnson Benjamin C. , Gordon Richard G. , Argus Donald F.
Published: May 2007

Previously, we estimated the angular velocity of the Nubian plate relative to the Somalian plate from an updated set of spreading rates and transform fault azimuths. We found that the Nubia‐Somalia plate boundary intersects the Southwest Indian Ridge (SWIR) between ≈26°E and ≈32°E if both the Nubian and Somalian plates are rigid and if the boundary between them is narrow. These prior results are not completely satisfactory mainly for two reasons: (1) The four‐plate circuit Somalia‐Antarctica‐Nubia‐Arabia does not close. (2) The largest (Mw ≤ 6.8) recorded “African” earthquakes that are near, but not along, the SWIR occur near 48°E, well east of the intersection with the Nubia‐Somalia boundary. Here we investigate these problems through detailed analysis of plate motion data, especially those along the SWIR east of the Andrew Bain Transform Fault Complex. We find an improved fit to the data and improved plate circuit closure if a region of the African lithosphere is interpreted as a new component plate. This new plate lies between the Nubian and Somalian plates along the SWIR and is separated from the latter by a diffuse boundary that includes the locations of the largest off‐ridge earthquakes. Following C. J. H. Hartnady, we call this new plate “Lwandle.” Use of this new plate geometry shifts the Nubia‐Somalia pole of rotation northeastward to just south of South Africa and thus alters estimates of current India‐Eurasia plate motion.