bluuebunny/crossref_metadata_2025 huggingface dataset:
Inter-household and intra-household patterns of fish and meat consumption in fishing communities in two states in Nigeria
Authors: Gomna Ahmed , Rana Krishen
Published: January 2007

Fish is generally regarded as a primary source of protein for many poor African fishing communities. The present study compared the relative importance of fish as a high-quality dietary protein source with meat in fishing communities in two states in Nigeria. Fifty fishing households in which active fishing was the primary activity and fifty non-fishing households (agriculture being stated as primary activity) in traditional fishing communities were randomly selected in the coastal state of Lagos and the inland state of Niger. A simple weighing balance was designed and given to each household to measure fish or meat entering the household for consumption. A comparison of consumption using this method against the 24 h recall method revealed that the recall method accounted for only one third of actual fish consumed. Overall, the price of fish was higher and consumption lower in Lagos compared with Niger State. At the household level in both states, the consumption of fish in fishing households was twice that of non-fishing households, whereas meat consumption was similar. A total of thirty-nine different fish species were consumed, with Tilapia contributing 24 % by weight of the fish consumed. In both states, beef was the most frequently consumed meat, followed by goat meat. The study revealed a high preference for fresh fish. The highest fish consumption occurred in March, corresponding to the period of lowest meat consumption. On a unit weight basis, heads of households consumed 59 % more fish than their wives or children.
Deposition of dietary fatty acids,de novosynthesis and anatomical partitioning of fatty acids in finishing pigs
Authors: Kloareg Maela , Noblet Jean , van Milgen Jaap
Published: January 2007

Predicting aspects of pork quality becomes increasingly important from both a nutritional and technological point of view. The aim of the present study was to provide quantitative information on the relation between nutrient intake and whole-body fatty acid (FA) deposition. This information is essential to develop mechanistic models predicting the FA content of tissues. A serial slaughter study was carried out in which thirty pigs were slaughtered between 90 and 150 kg. The diet included 15 g/kg soyabean oil and contained 44 g/kg fat. Only 0·31 and 0·40 of the digestedn-6 andn-3 FA were deposited, respectively. Approximately one-third of then-3 supply that was deposited resulted from the conversion of 18 : 3 to other metabolites (i.e. EPA, docosapentaenoic acid and DHA). This proportion was affected by the pig genotype.De novo-synthesised FA represented 0·86 of the total non-essential FA deposition, and its average composition corresponded to 0·017, 0·286, 0·025, 0·217 and 0·454 for 14 : 0, 16 : 0, 16 : 1, 18 : 0 and 18 : 1, respectively. Although the average whole-body FA composition was relatively constant during the finishing period, this was not so for the tissues. In the carcass (without backfat), the content of 18 : 1 increased during the finishing period, whereas that of 16 : 0 and 18 : 0 decreased. Backfat captured a proportionally greater fraction of 18 : 2 than did the carcass or the residual tissues. In contrast, a proportionally greater fraction of the dietary 18 : 3 supply was deposited in the carcass compared to other tissues.
The Driselase-treated fraction of rice bran is a more effective dietary factor to improve hypertension, glucose and lipid metabolism in stroke-prone spontaneously hypertensive rats compared to ferulic acid
Authors: Ardiansyah  , Shirakawa Hitoshi , Koseki Takuya , Hashizume Katsumi , Komai Michio
Published: January 2007

The aim of this study is to investigate the effects of dietary supplementation with the Driselase-treated fraction (DF) of rice bran and ferulic acid (FA) on hypertension and glucose and lipid metabolism in stroke-prone spontaneously hypertensive rats (SHRSP). Male SHRSP at 4 weeks of age were divided into three groups, and for 8 weeks were fed (1) a control diet based on AIN-93M, (2) a DF of rice bran-supplemented diet at 60 g/kg and (3) an FA-supplemented diet at 0·01 g/kg. Means and standard errors were calculated and the data were tested by one-way ANOVA followed by a least significance difference test. The results showed that both the DF and FA diets significantly improved hypertension as well as glucose tolerance, plasma nitric oxide (NOx), urinary 8-hydroxy-2′-deoxyguanosine and other parameters. In particular, compared to the FA diet, the DF diet produced a significant improvement in urinary NOx, hepatic triacylglycerol and several mRNA expressions of metabolic parameters involved in glucose and lipid metabolisms. The results of the metabolic syndrome-related parameters obtained from this study suggest that the DF diet is more effective than the FA diet.
Calcium absorption in postmenopausal Chinese women: a randomized crossover intervention study
Authors: Chen Yu-ming , Teucher Birgit , Tang Xin-yi , Dainty Jack R. , Lee Kenneth K. C. , Woo Jean L. F. , Ho Suzanne C.
Published: January 2007

The Ca intake and food sources of Chinese postmenopausal women are quite different from those of their Western counterparts. But, little information on Ca metabolism is available in Chinese populations. We determined true fractional calcium absorption (TFCA), true Ca absorption ( = TFCA × Ca intake,Va), urinary Ca excretion (Vu) and the difference betweenVaandVu(Va − u), in response to three dietary Ca intake levels. Twenty-one healthy postmenopausal Chinese women aged 49–64 years were recruited for this randomized crossover trial from a general community, Guangzhou, China. Subjects were randomly assigned to receive 0, 500 and 1000 mg Ca/d for 5 weeks separated by 2-week washout periods. TFCA using Ca stable isotopes, total urinary Ca excretion and Ca intake were determined after 4 weeks of adaptation. Mean values for total Ca intake (Vi) of the three phases were 391 (sd197), 880 (sd130) and 1382 (sd160) mg/d. On usual diet, TFCA,Vu,VaandVa − uwere 0·57 (sd0·12), 175 (sd59) mg/d, 216 (sd98) mg/d and 41 (sd99) mg/d, respectively. With the supplementations of 500 and 1000 mg Ca/d, TFCA significantly decreased to 0·52 (sd0·12) and 0·43 (sd0·13) (P < 0·001); whereas urinary Ca (P = 0·003),VaandVa − uincreased significantly (P < 0·001). Using a mixed-effects nonlinear regression model, it was estimated thatVa − uwas approaching a plateau when mean Ca intake reached 1300 mg/d. In conclusion, the present findings suggest postmenopausal Chinese women have high Ca absorption efficiency and a mean Ca intake of about 1300 mg/d is required to maximize theVa − u.
Dietary supplementation with an extract of lycopene-rich tomatoes does not reduce atherosclerosis in Watanabe Heritable Hyperlipidemic rabbits
Authors: Frederiksen Hanne , Rasmussen Salka E. , Schrøder Malene , Bysted Anette , Jakobsen Jette , Frandsen Henrik , Ravn-Haren Gitte , Mortensen Alicja
Published: January 2007

Tomatoes are rich in lycopene and other carotenoids which have shown beneficial effects on CVD in epidemiological and intervention studies. In the present study the effect of an extract of lycopene-rich tomatoes, Lyc-O-Mato®on atherosclerosis was studied in Watanabe Heritable Hyperlipidemic rabbits. The rabbits were fed a control diet, a control diet supplemented with the tomato extract or a control diet supplemented with a mixture of plant oils for 16 weeks. Lycopene was detected only in plasma of rabbits receiving tomato extract. The tomato extract had no effect on cholesterol and triacylglycerol levels measured in total plasma, lipoprotein fractions and on aortic atherosclerosis evaluated biochemically and by microscopy. Oxidation of lipids in unfractionated plasma also was unaffected by the intake of tomato extract. In conclusion, the tomato extract increased plasma levels of lycopene in rabbits, but had no effect on hypercholesterolaemia, oxidation of plasma lipids or aortic atherosclerosis.
Composition and metabolism of the intestinal microbiota in consumers and non-consumers of yogurt
Authors: Alvaro Elise , Andrieux Claude , Rochet Violaine , Rigottier-Gois Lionel , Lepercq Pascale , Sutren Malène , Galan Pilar , Duval Yvonne , Juste Catherine , Doré Joël
Published: January 2007

The objective of the present study was to evaluate the impact of a regular consumption of yogurt on the composition and metabolism of the human intestinal microbiota. Adult subjects were selected on the basis of daily food records and divided into two groups: yogurt consumers (at least 200 g yogurt consumed per d,n30); non-consumers (no yogurt,n21). Their faecal microbiota was analysed using molecular methods (in situhybridisation and PCR amplification combined with separation by denaturing gel electrophoresis) and its metabolic characteristics were assessed by measuring glycosidase, β-glucuronidase and reductase activities and profiling SCFA, neutral sterols and bile acids. The yogurt starterLactobacillus delbrueckiissp.bulgaricus(identity confirmed by 16S rRNA sequencing) was detected in 73 % of faecal samples from fermented milk consumersv. 28 % from non-consumers (P = 0·003). In yogurt consumers, the level of Enterobacteriaceae was significantly lower (P = 0·006) and β-galactosidase activity was significantly increased (P = 0·048). In addition, within this group, β-galactosidase activity and theBifidobacteriumpopulation were both positively correlated with the amount of fermented milk ingested (r0·66,P < 0·0001 andr0·43,P = 0·018, respectively). Apart from these effects, which can be considered beneficial to the host, no other major differences could be detected regarding the composition and metabolic activity of intestinal microbiota.
Dietary soya protein during pregnancy and lactation in rats with hereditary kidney disease attenuates disease progression in offspring
Authors: Cahill Leah E. , Peng Claudia Yu-Chen , Bankovic-Calic Neda , Sankaran Deepa , Ogborn Malcolm R. , Aukema Harold M.
Published: January 2007

Dietary soya protein substitution for casein initiated at weaning slows disease progression in animal models of chronic renal disease. As there is increasing evidence that fetal programming can have a significant impact on kidney physiology and function in offspring, the objective of the current study was to determine whether exposure to soya protein in the diet earlier than weaning would have further benefits. Han:SPRD-cy(cy/+) breeder rats were fed a casein-based or soya protein-based diet 2 weeks prior to mating, throughout pregnancy and during lactation. Following this maternal period, 3-week-old pups were given either the same or the alternate diet for a 7-week weaning period. Dietary soya protein compared with casein in the maternal or weaning period both independently resulted in less renal inflammation (macrophage infiltration lower by 24 % (P = 0·0003) and 32 % (P < 0·0001), respectively). When soya protein was given in both feeding periods, the effect was additive. Soya protein substitution for casein resulted in less oxidative damage as indicated by 28 % lower oxidized-LDL staining (P = 0·013) when present in the maternal period, or in the weaning period (by 56 %,P < 0·0001). Renal cell proliferation was reduced by 29–33 % (P < 0·05) in rats given soya protein whether the exposure was during the maternal or weaning period. Soya protein compared with casein in the maternal period also resulted in 33 % (P = 0·0013) less proteinuria, indicating superior renal function. Dietary soya protein during pregnancy and lactation represents a potential preventative approach in treating for those with congenital kidney diseases.
Long-term dietary compensation for added sugar: effects of supplementary sucrose drinks over a 4-week period
Authors: Reid Marie , Hammersley Richard , Hill Andrew J. , Skidmore Paula
Published: January 2007

The long-term physiological effects of refined carbohydrates on appetite and mood remain unclear. Reported effects when subjects are not blind may be due to expectations and have rarely been studied for more than 24 h. The present study compared the effects of supplementary soft drinks added to the diet over 4 weeks on dietary intake, mood and BMI in normal-weight women (n133). Subjects were categorised as ‘watchers’ or ‘non-watchers’ of what they ate then received sucrose or artificially sweetened drinks (4 × 250 ml per d). Expectancies were varied by labelling drinks ‘sugar’ or ‘diet’ in a counter-balanced design. Sucrose supplements provided 1800 kJ per d and sweetener supplements provided 67 kJ per d. Food intake was measured with a 7 d diary and mood with ten single Likert scales. By 4 weeks, sucrose supplements significantly reduced total carbohydrate intake (F(1,129) = 53·81;P < 0·001), fat (F(2,250) = 33·33;P < 0·001) and protein intake (F(2,250) = 28·04;P < 0·001) compared with sweetener supplements. Mean daily energy intake increased by just under 1000 kJ compared with baseline (t(67 df) = 3·82;P < 0·001) and was associated with a non-significant trend for those receiving sucrose to gain weight. There were no effects on appetite or mood. Neither dietary restraint status as measured by the Dutch Eating Behaviour Questionnaire nor the expectancy procedure had effects. Expectancies influenced mood only during baseline week. It is concluded that sucrose satiates, rather than stimulates, appetite or negative mood in normal-weight subjects.
The B'Active programme for overweight primary school children in Glasgow: determining the prevalence of overweight and obesity and piloting an activity intervention
Authors: Hughes Adrienne R. , McLaughlin Ruth , Mckay Jane , Lafferty Kevin , McKay Tony , Mutrie Nanette
Published: January 2007

The aim of this study was to determine the prevalence of overweight and obesity in primary school children in Glasgow and to evaluate a pilot activity programme for overweight and obese children. BMI was measured in 1548 children. Overweight, obesity and severe obesity were defined as BMI ≥ 85th, 95th and 98th centile, respectively. Overweight and obese children were then invited to participate in a 10-week school-based activity programme. The programme was evaluated by recording weekly attendance, intensity (using the Children's Effort Rating Scale) and enjoyment (scale 1–10). Focus groups were used to explore the experiences and views of the children, teachers, coaches and parents. Of the 1548 children, 31·4 % were overweight, 19·1 % were obese and 12·4 % were severely obese; 38 % of those invited attended the activity programme. Weekly programme attendance was 83 % (range 56–99 %). Mean enjoyment rating (scale 1–10) was 8 for boys and 9 for girls. The intensity of activity sessions were rated ‘very easy’ by boys and ‘just feeling a strain’ by girls. Common themes emerging from the focus groups related to perceived positive and negative aspects of the programme (fun, concerns about stigmatising children); physical and psychological outcomes (fitter, more confident); and future recommendations (involve parents). In summary, the prevalence of overweight and obesity was high. The activity programme was successful in terms of attendance and enjoyment, and overall views of the initiative were positive and there was compelling support for its continuation.
Vegetation structure and ungulate abundance over a period of increasing elephant abundance in Hwange National Park, Zimbabwe
Authors: Valeix Marion , Fritz Hervé , Dubois Ségolène , Kanengoni Kwanele , Alleaume Samuel , Saïd Sonia
Published: January 2007

This study investigates whether increases in elephant populations may influence the structure of African savannas, and consequently may affect other herbivores through changes in habitats. Two contrasting periods in terms of elephant population densities were compared in Hwange National Park, Zimbabwe: the early 1980s and the late 1990s. Elephant population density and other ungulate population densities were estimated for a c. 400-km2 area from road counts. Vegetation structure at the landscape scale was assessed using aerial photographs for the same area. All browsers and grazers declined between the early 1980s and the late 1990s, whereas elephants experienced a 16-fold increase. At the landscape scale, vegetation structure changed little with no evidence of an opening of the habitats. These results do not support any kind of medium-term facilitation between elephants and other herbivores. They rather suggest a negative effect of elephants on other herbivore species when elephants are present at high densities. This study rules out a scenario where the decrease of the different herbivore populations was caused by large changes in vegetation structure due to elephant activity.
Predation on artificial nests and caterpillar models across a disturbance gradient in Subic Bay, Philippines
Authors: Posa Mary Rose C. , Sodhi Navjot S. , Koh Lian Pin
Published: January 2007

One possible mechanism underlying species losses in the tropics is an increase in predation due to habitat degradation. Relative levels of predation at three heights (ground, 1–1.5 m, > 5 m for nests and > 3 m for caterpillars) were compared across a gradient of disturbance in the Subic Bay Watershed Forest Reserve, Philippines over a 2-mo period. Four 750-m transects were established in each habitat type (closed-canopy forest, open-canopy forest, rural areas) where artificial nests and caterpillar models were placed within 10-m-radius plots and checked after a 5-d exposure period. Nests in open-canopy forest were least predated (16.7%), with predation in rural areas (58.3%) being higher than in closed-canopy forest (32.8%). Predation on nests at 1–1.5 m was significantly lower than ground nests. General linear mixed model analysis suggested that effects of habitat type on nest predation differed among heights. Attacks on caterpillars increased with disturbance (46.1–59.4%), but height was not found to have a significant effect on predation. Markings on plasticine models, camera traps and live traps were used to establish possible predators. Shifts in predator dominance among the habitats were observed. Vegetation cover, tree density and small mammal abundance were not correlated with mean predation in the transects.
Drivers of rain-forest boundary dynamics in Kakadu National Park, northern Australia: a field assessment
Authors: Banfai Daniel S. , Bowman David M. J. S.
Published: January 2007

Understanding the causes of savanna–forest dynamics is vital as small but widespread changes in the extent of tropical forests can have major impacts on global climate, biodiversity and human well-being. Comparison of aerial photographs for 50 rain-forest patches in Kakadu National Park had previously revealed a landscape-wide monotonic expansion of rain-forest boundaries between 1964 and 2004. Here floristic, structural, environmental and disturbance attributes of the changes were investigated by sampling 588 plots across 30 rain-forest patches. Areas that had changed from savanna to rain forest were associated with a significantly higher abundance of rain-forest trees and less grasses, relative to stable savanna areas. Ordination analyses showed that overall floristic composition was not significantly different between newly established rain forest and longer established rain forest. Generalized linear models also indicated that contemporary levels of disturbance (fire and feral animal impact) and environmental variables (slope and soil texture) were poor predictors of historical vegetation change. We concluded that (1) the rain-forest boundaries are highly dynamic at the decadal scale; (2) rain-forest expansion is consistent with having been driven by global environmental change phenomena such as increases in rainfall and atmospheric CO2; and (3) expansion will continue if current climatic trends and management conditions persist.
Effect of three species of climber on the performance of Ceiba pentandra seedlings in gaps in a tropical forest in Ghana
Authors: Toledo-Aceves Tarin , Swaine M. D.
Published: January 2007

The proliferation of climbers can have deleterious effects on tree regeneration, especially in forest canopy gaps where climbers increase in abundance. In response to the colonization by climbers, the supporting tree can suffer a reduction in growth and its allometric relationships may be modified. We evaluated the effects of three species of climber on the performance of the pioneer tree Ceiba pentandra in a moist semi-deciduous tropical forest in Ghana. In each of three gaps, four plots were set up, each with eight Ceiba seedlings paired with a single plant of one of three climber species, planted within 5–10 cm of the tree seedling, plus a control (no climber). The climber species were: Centrosema pubescens, a nitrogen-fixing woody climber; Combretum racemosum, a woody climber and Dioscorea praehensilis, an herbaceous climber. After 12 mo, Centrosema and Combretum had about four to five times more biomass than Ceiba seedlings. There was no effect of climber competition on Ceiba biomass growth, and no relationship between climber biomass and Ceiba growth rate. Individual climber species, however, had other effects: Combretum caused a significant reduction in the height and diameter growth of Ceiba, whilst competition with Centrosema was associated with significant reduction in the crown area and increase in internode length in Ceiba. The results indicate that even very different climber species appear to cause negative effects on trees during regeneration.
Effect of ingestion by two frugivorous bat species on the seed germination of Ficus racemosa and F. hispida (Moraceae)
Authors: Tang Zhan-Hui , Mukherjee Aeshita , Sheng Lian-Xi , Cao Min , Liang Bing , Corlett Richard T. , Zhang Shu-Yi
Published: January 2007

Frugivorous bats are important seed dispersers for many plant species (Cox et al. 1991, Fleming & Heithaus 1981, Hodgkison et al. 2003a, McConkey & Drake 2006, Nyhagen et al. 2005, Utzurrum 1995). They regularly consume figs in the wild (Fujita & Tuttle 1991, Kalko et al. 1996, Shilton et al. 1999). Various species of pteropodid bats have been reported foraging on the fruits of more than 30 fig species in tropical and subtropical Asia, Africa and Australia (Bhat 1994, Fujita & Tuttle 1991, Marshall & McWilliam 1982, Thomas 1984). Food transit times in frugivorous bats are relatively rapid; generally less than 30 min (Laska 1990, Tedman & Hall 1985). Several studies have demonstrated that seed germination was either enhanced or unaffected after passage through the digestive tract of bats (Figueiredo & Perin 1995, Fleming & Heithaus 1981, Lieberman & Lieberman 1986).
A helium isotope cross‐section study through the San Andreas Fault at seismogenic depths
Authors: Wiersberg Thomas , Erzinger Jörg
Published: January 2007

We have analyzed noble gas isotopes in 19 mud gas samples from 116–3943 m borehole depth of the San Andreas Fault Observatory at Depth (SAFOD) Main Hole in the context of origin and spatial variability of fluids occurring at seismogenic depths. The measured 3He/4He ratios range between 0.40 and 1.02 Ra (Ra is the atmospheric 3He/4He ratio of 1.39 × 10−6), with 4He/20Ne values between 0.33 and 4.92, revealing a mixture of three components to the total helium: (1) atmospheric helium, (2) helium with a crustal signature, and (3) mantle‐derived helium. The air‐corrected 3He/4He ratios fall between 0.2 Ra and 0.9 Ra. Samples from the 2117–3196 m depth show a relatively constant helium isotope composition (0.35–0.46 Ra), indicating that ∼5% of the helium in this section the Pacific Plate is derived from the mantle. The contribution of mantle‐derived helium increases slightly in the transition from the Pacific Plate to the North American Plate and reaches maximal values of ∼12% on the North American Plate (below ∼3500 m borehole depth). On the basis of our observations, we suggest that the San Andreas Fault plays a role for fluid flux from greater depths, but higher amounts of mantle‐derived fluids rise up through other, more permeable faults, situated on the North American Plate of the San Andreas Fault Zone (SAFZ). Lateral fluid dispersion at shallow depths through permeable country rock of the North American Plate may explain the observed increase in 3He/4He ratios with increasing distance to the SAF.
Reconstruction of seismic faulting by high‐velocity friction experiments: An example of the 1995 Kobe earthquake
Authors: Mizoguchi Kazuo , Hirose Takehiro , Shimamoto Toshihiko , Fukuyama Eiichi
Published: January 2007

High‐velocity friction experiments on a fault gouge collected from the Nojima fault activated during the 1995 Kobe earthquake showed that the friction coefficient decreased from 0.63 to 0.18 over a slip weakening distance, Dc, at high slip rates of ∼ 1 m/s. The dramatic drop in friction coefficient of more than 0.3 is consistent with that for the Kobe earthquake estimated from seismological observations. Experimentally determined Dc becomes 5 m at a higher normal stress of 1.85 MPa, close to the order of magnitude of seismologically determined Dc of 0.5 to 1 m. The difference in Dc is not significant because the fracture energy consumed during frictional slip is the same order of 106 N/m for both cases. Here we show that frictional behavior of a fault during an earthquake can be predicted by conducting high‐velocity friction experiments.
A single model ensemble versus a dynamic modeling platform: Semi‐distributed rainfall runoff modeling in a Hierarchical Mixtures of Experts framework
Authors: Marshall Lucy , Sharma Ashish , Nott David
Published: January 2007

One way to address the perceived biases in many hydrological model simulations is to incorporate the information from several models at once. In this study we present an alternative where the catchment can be modeled as existing under a number of discrete states, which are chosen in a probabilistic manner based on selected catchment indicators. We present an application of the approach in the context of a semi‐distributed catchment simulation model. We compare the predictive performance of several observed and simulated catchment indicators for aggregating the models via three catchments in different continental, geographic and climatic settings. Two main conclusions are drawn: (a) the multiple state representation of catchment behavior is an attractive alternative to single model parameterizations in terms of predictive power, and (b) each of the discrete probabilistic states is predictable using catchment indicators that reflect the lower order runoff producing mechanisms.
Shock‐induced compaction, melting, and entrapment of atmospheric gases in Martian meteorites
Authors: Beck P. , Ferroir T. , Gillet P.
Published: January 2007

The strongest evidence for a Martian origin of the SNC meteorites is the strong correlation between the rare gas abundances and isotopic compositions in shock‐induced melt pockets, and those measured for the Martian atmosphere. However, the formation of melt pockets and the entrapment of atmospheric gases remain poorly understood. Here we report the presence in the melt pockets of three Martian meteorites of the hollandite‐structured high‐pressure polymorph of feldspar. These occurrences set constraints on the continuum pressure (21–25 GPa), the local temperature increase (2000–2500 K) and the energy delivered during shock. We then test a mechanism for melt pocket formation by compaction of pre‐existing porous precursors. The model explains the local temperature increase required for melting and the presence of an atmospheric component in pores that were connected with the Martian atmosphere prior to the shock event.
Thermal properties across the Chelungpu fault zone and evaluations of positive thermal anomaly on the slip zones: Are these residuals of heat from faulting?
Authors: Tanaka H. , Chen W. M. , Kawabata K. , Urata N.
Published: January 2007

Thermal properties of the fault zone materials are of fundamental importance for estimate of frictional heat generation during earthquake. The properties across the Chelungpu fault zone activated by 1999 Chi‐Chi earthquake, Taiwan, are measured using the drilled core penetrating the fault zone at around 1100 m depth. The fault zone contains four distinct fracture zones, each of which includes thin slip zones. Thermal conductivity (K) lies between 1.0 and 3.0 Wm−1K−1 and shows the lowest value at the slip zones. Thermal diffusivity (α) varies between 0.8 to 2.0 × 10−6 m2s−1, and is relatively low at the slip zones. Density (ρ) varies between 2200 to 2800 kgm−3 and shows the lowest values at a particular slip zone (1110 m depth). Specific heat (c) is calculated by using above data resulting in the values from 300 to 1000 Jkg−1K−1, and lowest values for slip zones. Using these data and spectral gamma ray logs, reported positive thermal anomalies at the slip zones are re‐examined whether they are regarded as residual heat from friction by faulting.
On the formation of near‐Earth X‐line at substorm expansion onset
Authors: Kan J. R.
Published: January 2007

Convection in the plasma sheet can be enhanced by the MDXL (middle‐to‐distant X‐line) during the growth phase and by the NEXL (near‐Earth X‐line) during the expansion phase. Cowling current intensifies by the blockage of the northward Hall current due to lack of the radial currents or azimuthal pressure gradient in the midnight sector of the near‐Earth plasma sheet. Interaction of intensified Cowling current loop with the near‐Earth plasma sheet causes dipolarization. Dipolarization‐induced thinning tailward of the dipolarizing region can cause the NEXL formation to drive the substorm expansion phase. Further intensifications of the Cowling current in the substorm current wedge, the tailward expansion of dipolarization region, and the expansion of the auroral bulge are all driven by the NEXL during the expansion phase.
Training in the Timeshare Industry
Authors: Hicks G. Jane , Walker Misti D.
Published: January 2007

The timeshare industry's special challenges and its related needs for training are reviewed. Existing sources of timeshare industry training are outlined. Prospective applications for computer-based training are discussed; particularly online training that lends itself to just-in-time instruction.
The Perceived Influence of Centralising Operations in Chain Hotels
Authors: Espino-Rodríguez Tomás F. , Taylor J. Stephen
Published: January 2007

This paper makes an exploratory study of the centralisation of operations in hotels that belong to a chain and are located in a tourist destination. Although hotels are increasingly using a strategy of operations centralisation, little research has addressed the impact of that centralisation on the strategic business units (hotels). First, this study analyses the degree of centralisation of the hotel operations across the hotel chains examined. These operations constitute the activities or business processes that are necessary to provide the hotel service. Secondly, this work examines the perceived influence that operations centralisation has on the operation's competitive value for the strategic business unit from the resource-based view of the firm. Thirdly, it analyses the influence of operations centralisation on the operational performance of the hotel. A survey instrument was developed and data were collected from a field study of 32 hotels belonging to 16 different hotel chains operating in a European tourist destination. The results of this study indicate that the most centralised operations are those that require specific skills and knowledge, as well as those that are less valuable for the hotels. They also show that the degree of centralisation has an influence on some aspects of operational performance related to human resources. This work shows the influence that each operation has on operational performance, depending on its degree of centralisation.
Quality Management Initiatives in Irish Hotels — Emerging Agendas in a Changing Environment
Authors: Harrington Denis , Keating Mary
Published: January 2007

This paper reports a quantitative study on the implementation of quality programmes in the Irish hotel industry. An extensive survey was carried out of all hotels registered with the Irish Tourism board. The study assesses the level to which Irish hotels use formal quality methodologies to manage quality in their organisations. Analysis of the data indicates that adoption of formal methodologies within the sector is limited. While quality management is focused on involvement, communication, and teamwork, the study suggests that the management of quality in contemporary Irish hospitality organisations is lacking in precisely these dimensions. The paper concludes that training and development for quality is fragmented and intermittent at best. Irish hoteliers while recognising the importance of quality have few specific quality mechanisms in place.
A Canonical Correlation Analysis of E-Relationship Marketing and Hotel Financial Performance
Authors: Jang SooCheong (Shawn) , Hu Clark , Bai Billy
Published: January 2007

Hotel companies have used their websites to nurture customer relationships. One question is whether or not relationship marketing (RM) pays. The evidence of this empirical study involving 39 top hotel companies indicated a strong canonical correlation between the level of website development in relationship marketing and financial performance. In the proposed three-level e-relationship marketing ‘financial’ model (Basic, Accountable, and Partnership), a significant canonical variate disclosed that the ‘basic’ level and the ‘partnership’ level were positively correlated to the changes in sales revenue but negatively correlated to net income. This finding may imply that relatively more capital investment is necessary to create basic e-relationships and upgrade online customers to the partnership level than to maintain e-relationships at the ‘accountable’ level.
Influence of initial surface reconstruction on nitridation of Al2O3 (0001) using low pressure ammonia
Authors: Agnarsson B. , Göthelid M. , Olafsson S. , Gislason H. P. , Karlsson U. O.
Published: January 2007

The purpose of this study is to investigate the effect of initial surface reconstruction on the nitridation process of Al2O3 (0001). This was done by exposing differently reconstructed sapphire substrates at different temperatures to low pressure ammonia (NH3). Structural and chemical analysis were carried out using low-electron energy diffraction and x-ray photoelectron spectroscopy. The experiments revealed that using low pressure ammonia (PNH3<1×10−5 Torr), no nitridation takes place on (1×1) unreconstructed surfaces. However, when the unreconstructed surface starts to change to a (31×31)R±9° reconstructed surface, with increasing substrate temperature, the nitridation becomes successful. When using the initially reconstructed surface, the nitridation is successful even from the lowest temperature used. These results suggest that the initial surface reconstruction has a major effect on the nitridation process. This kinetic behavior has not been reported before, with most nitridation studies mainly focusing on the effect of surface temperature on the resulting surface morphology, rather than the actual kinetics of the process itself.
Attachment loss of micromechanical and nanomechanical resonators in the limits of thick and thin support structures
Authors: Judge John A. , Photiadis Douglas M. , Vignola Joseph F. , Houston Brian H. , Jarzynski Jacek
Published: January 2007

Analytical expressions are provided for the energy loss from vibrating mechanical resonators into their support structures for two limiting cases: supports that can be treated as plates, and supports that act as semi-infinite elastic media, with effectively infinite thickness. The former case is applicable to many microscale resonators, while the latter is appropriate for nanoscale devices. General formulations are given, applicable to a wide range of resonator geometries. These formulations are then applied to two geometries commonly used in microelectromechanical systems and nanelectromechanical systems applications: cantilevered beams and doubly fixed beams. Experimental data are presented to validate the finite-thickness support theory, and the predictions of the theory are also compared to data from existing literature for a microscale rectangular paddle oscillator.
Effective optical properties of absorbing nanoporous and nanocomposite thin films
Authors: Garahan Anna , Pilon Laurent , Yin Juan , Saxena Indu
Published: January 2007

This paper aims at developing numerically validated models for predicting the through-plane effective index of refraction and absorption index of nanocomposite thin films. First, models for the effective optical properties of such materials are derived from previously reported analysis applying the volume averaging theory (VAT) to Maxwell’s equations. The transmittance and reflectance of nanoporous thin films are computed by solving Maxwell’s equations and the associated boundary conditions at all interfaces using finite element methods. The effective optical properties of the films are retrieved by minimizing the root mean square of the relative errors between the computed and theoretical transmittance and reflectance. Nanoporous thin films made of SiO2 and TiO2 consisting of cylindrical nanopores and nanowires are investigated for different diameters and various porosities. Similarly, electromagnetic wave transport through dielectric medium with embedded metallic nanowires are simulated. The numerical results are compared with predictions from widely used effective property models including (1) the Maxwell-Garnett theory, (2) the Bruggeman effective medium approximation, (3) the parallel, (4) series, (5) Lorentz-Lorenz, and (6) the VAT models. Very good agreement is found with the VAT model for both the effective index of refraction and absorption index. Finally, the effect of volume fraction on the effective index of refraction and absorption index predicted by the VAT model is discussed. For certain values of wavelengths and volume fractions, the effective index of refraction or absorption index of the composite material can be smaller than that of both the continuous and dispersed phases. These results indicate guidelines for designing nanocomposite materials with desired optical properties.
Very high-cycle fatigue failure in micron-scale polycrystalline silicon films: Effects of environment and surface oxide thickness
Authors: Alsem D. H. , Timmerman R. , Boyce B. L. , Stach E. A. , De Hosson J. Th. M. , Ritchie R. O.
Published: January 2007

Fatigue failure in micron-scale polycrystalline silicon structural films, a phenomenon that is not observed in bulk silicon, can severely impact the durability and reliability of microelectromechanical system devices. Despite several studies on the very high-cycle fatigue behavior of these films (up to 1012cycles), there is still an on-going debate on the precise mechanisms involved. We show here that for devices fabricated in the multiuser microelectromechanical system process (MUMPs) foundry and Sandia Ultra-planar, Multi-level MEMS Technology (SUMMiT V™) process and tested under equi-tension/compression loading at ∼40kHz in different environments, stress-lifetime data exhibit similar trends in fatigue behavior in ambient room air, shorter lifetimes in higher relative humidity environments, and no fatigue failure at all in high vacuum. The transmission electron microscopy of the surface oxides in the test samples shows a four- to sixfold thickening of the surface oxide at stress concentrations after fatigue failure, but no thickening after overload fracture in air or after fatigue cycling in vacuo. We find that such oxide thickening and premature fatigue failure (in air) occur in devices with initial oxide thicknesses of ∼4nm (SUMMiT V™) as well as in devices with much thicker initial oxides ∼20nm (MUMPs). Such results are interpreted and explained by a reaction-layer fatigue mechanism. Specifically, moisture-assisted subcritical cracking within a cyclic stress-assisted thickened oxide layer occurs until the crack reaches a critical size to cause catastrophic failure of the entire device. The entirety of the evidence presented here strongly indicates that the reaction-layer fatigue mechanism is the governing mechanism for fatigue failure in micron-scale polycrystalline silicon thin films.
Large two-photon absorptivity of hemoglobin in the infrared range of 780–880nm
Authors: Clay G. Omar , Schaffer Chris B. , Kleinfeld David
Published: January 2007

Porphyrin molecules have a highly conjugated cyclic structure and are theorized to have unusually large two-photon absorptivities (σTPA), i.e., σTPA∼102GM. The authors tested this claim. Ultrafast two-photon absorption (TPA) spectroscopy was performed on solutions of hemoglobin, which contains a naturally occurring metaloporphyrin. They used a pump-probe technique to directly detect the change in transmission induced by TPA over the wavelength range of λ0=780–880nm. As controls, they measured the TPA of the dyes rhodamine 6G and B; their measurements both verify and extend previously reported values. In new results, hemoglobin was found to have a peak two-photon absorptivity of σTPA∼150GM at λ0=825nm, near a resonance of the Soret band. This value supports theoretical expectations. They also found a significant difference in the TPA of carboxyhemoglobin versus oxyhemoglobin, e.g., σTPA=61GM versus σTPA=18GM, respectively, at λ0=850nm, which shows that the ligand affects the electronic states involved in TPA.
Influence of TiO2 and ZnO on the conductivity and dielectric properties of copper-bismuth glasses
Authors: Shukla D. K. , Mollah S. , Kumar Ravi
Published: January 2007

Influence of TiO2 and ZnO oxides has been investigated elaborately on the conductivity and dielectric properties of unconventional and technologically important 40CuO–40Bi2O3–20X (where X=TiO2 and ZnO) glasses. The dc electrical conductivity of ZnO containing glass is found to be higher than that of TiO2 containing one at all temperatures (300–600K). A change from adiabatic to nonadiabatic small polaron hopping conduction is observed due to the influence of TiO2 and ZnO oxides. It has been perceived that the ZnO doped glass shows relatively more ac conductivity compared to that of the TiO2 doped one, consistent with the dc conductivity data. Random-free-energy barrier model of Dyre [J. Appl. Phys. 64, 2456 (1988)] is suited to be the most appropriate one for explaining the frequency dependence of ac conductivity data and frequency exponent. The large dielectric constant in both the glasses can be explained by the response of Bi3+ ions to ac.
Effect of free volume and temperature on the structural relaxation in polymethylphenylsiloxane: A positron lifetime and pressure-volume-temperature study
Authors: Dlubek G. , Shaikh M. Q. , Krause-Rehberg R. , Paluch M.
Published: January 2007

The microstructure of the free volume and its temperature dependence in polymethylphenylsiloxane (PMPS) have been examined using positron annihilation lifetime spectroscopy (PALS) and pressure-volume-temperature experiments. The hole-free volume fraction h and the specific hole-free and occupied volumes, Vf=hV and Vocc=(1−h)V, were estimated employing the Simha-Somcynsky (SS) lattice-hole theory. From the PALS spectra analyzed with the new routine LT9.0 the hole size distribution, its mean, ⟨νh⟩, and mean dispersion, σh, were calculated. A comparison of ⟨νh⟩ with V and Vf delivered a constant specific hole number Nh′. Using a fluctuation approach the temperature dependency of the volume of the smallest representative freely fluctuating subsystem, ⟨VSV⟩, is estimated to vary from ∼8.5nm3 at Tg to ∼3nm3 at T∕Tg⩾1.15. Unlike other polymers, the segmental relaxation from dielectric spectroscopy of PMPS follows the Cohen-Turnbull free volume theory almost perfectly in the temperature and pressure ranges between 243 and 279K and 0 and ∼100MPa. This behavior correlates with the small mass of the SS lattice mer which indicates the high flexibility of the PMPS chain. Above 293K and ∼150MPa, the free volume prediction gives relaxation times that are too small, which indicates that effects of thermal energy must be included in the analysis. To quantify the degree to which volume and thermal energy govern the structural dynamics the ratio of the activation enthalpies, Ei=R[(dlnτ∕dT1)]i (τ-relaxation time of α relaxation), at constant volume V and constant pressure P,EV∕EP, is frequently determined. The authors present arguments for necessity to substitute EV with EVf, the activation enthalpy at constant (hole) free volume, and show that EVf∕EP changes as expected: increasing with increasing free volume, i.e., with increasing temperature and decreasing pressure. EVf∕EP(=0.04–0.1) exhibits remarkably smaller values than EV∕EP(=0.44– 0.53), which leads to the inference that the free volume plays a distinctly larger role in dynamics than traditionally concluded from EV∕EP. This conclusion is in agreement with the results of our more direct Cohen-Turnbull free volume analysis.
Theoretical study on high-speed modulation of Fabry-Pérot and distributed-feedback quantum-dot lasers: K-factor-limited bandwidth and 10Gbit∕s eye diagrams
Authors: Ishida Mitsuru , Sugawara Mitsuru , Yamamoto Tsuyoshi , Hatori Nobuaki , Ebe Hiroji , Nakata Yoshiaki , Arakawa Yasuhiko
Published: January 2007

This paper presents a theoretical study of the high-speed modulation response of Fabry-Pérot (FP) and distributed-feedback (DFB) quantum-dot lasers based on the rate equation models, making reference to available experimental data. We show that the K-factor-limited maximum modulation bandwidth increases with the maximum optical gain and that there is an optimum cavity loss to maximize the bandwidth at a given maximum gain, enabling us to design the bandwidth of FP lasers as well as DFB lasers with and without a phase shift. We present modulation wave forms of FP quantum-dot lasers to indicate that the maximum modal gain of 30–40cm−1 is sufficient for 10Gbit∕s eye opening, which explains the recent success of 10Gbit∕s modulation of the quantum-dot laser with ten dot layers in the active region having the maximum modal gain of 35cm−1. We show a design for low-driving-current 10Gbit∕s operation by shortening the cavity length with the optimum cavity loss maintained by the high-reflectivity coating.
Persistent photoconductivity in highly porous ZnO films
Authors: Reemts Jens , Kittel Achim
Published: January 2007

ZnO and ZnO-dye hybrid films prepared by electrochemical deposition are highly porous if fabricated in the presence of structure directing agents and they can easily be sensitized by various molecules. If the material is sensitized with the appropriate molecules, it becomes interesting for various sensor applications, i.e., gas sensors and biosensors, or as an electrode material for solar energy conversion in dye sensitized solar cells. In the present work, the focus is on dye sensitized ZnO as a model system. The long term photoconductivity transients have been investigated in such kind of material. Upon excitation with different wavelengths, the conductivity increases already under sub-band-gap illumination due to widely distributed trap states within the band gap. The slow photoconductivity transients follow a stretched exponential law if the illumination is rapidly changing in a dry atmosphere. The underlying mechanism of persistent photoconductivity can be attributed to a lattice relaxation process of surface states, immediately after electrons have been photoexcited into distributed surface states located inside the band gap of the ZnO thin film.