bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal patterns of energy allocation to basal metabolism, activity and production for livestock in a nomadic pastoral ecosystem
Authors: Coppock D. L. , Swift D. M. , Ellis J. E. , Galvin K.
Published: March 2009

Energy budgets and estimates of forage intake requirements were developed for adult camels, cattle, sheep, and goats managed by nomads in the arid Turkana District of north-western Kenya. The estimates were developed by combining our field data on livestock activity patterns, diet quality, weight changes and milk yields with literature based estimates of the associated costs and efficiencies. On an annual basis, the average animal walked 17 km/day and had a total metabolizable energy (ME) allocation of 47% for basal metabolism, 16% for travel, 14% for other activities, and 23% for production. Season and species influenced patterns of energy demand and allocation. Average daily ME requirements ranged from 8·7 MJ (sheep) to 76·7 MJ (camels). ME demand for all species peaked during wet (April-May) or early-to mid-dry periods (June-October), and decreased considerably in the late-dry season (November-March). In the wet season the average sheep or goat allocated 45% of its ME budget to production of milk and gain, followed by cattle (36%) and camels (25%). All species were more similar in ME allocation for production during the late-dry season (7–13%; all to lactation), yet patterns of weight loss during this time indicated that camels experienced the lowest degree of negative energy balance. On an annual basis, camel budgets were the most deviant, as they allocated relatively more ME to activity and relatively less to basal metabolism or weight gain. Estimates of forage dry-matter intakes (per unit live weight per day) ranged from 3·8% (cattle, camels) to 4·6% (sheep, goats) throughout the year, and intakes declined for most species by an average of 50% from the wet to late-dry intervals. This approach has revealed ecological differences among livestock species that help explain the utility of multi-species holdings in this system.
Response of green gram (Vigna radiata(L.) Wilczek) to bacterial seed inoculation and application of phosphorus fertilizer
Authors: Kothari S. K. , Saraf C. S.
Published: March 2009

Nitrogen fixing, free-living, organisms likeAzotobacterandAzospirillumare known to increase the nodulation and efficiencyoiRhizobium(Krasilinikov & Korenyakov, 1944). The beneficial effect of incorporation ofAzotobacterwithRhizobiummay be due to the production of auxins (Vancura & Macura, 1960) and prolonged survival ofRhizobiumin the presence of a large amount of polysaccharide gums (Krasilinikov & Korenyakov, 1944). In green gram (Vigna radiataL. Wilczek), because of high temperature and unavoidable soil moisture stress during hot and dry summer months (April-June), survival of the seed-inoculatedRhizobiumis very poor (Lai, Dubey & Chandra, 1983). In the present study attempts were made to improve the efficiency cfRhizobiumas an inoculant by the use ofAzotobacter chroococcumandAzospirillum brasilense.
Use of wood ash, dry chilli pepper fruits and onion scale leaves for reducing Callosobruchus maculatus (Fabricius) damage in cow-pea seeds during storage
Authors: Ofuya T. I.
Published: March 2009

Callosobruchus maculatus (F.) is a very serious pest of cow pea in storage in Nigeria and many other oountries (Singh, 1977; Tindall, 1983). Damaged seeds are riddled with emergence holes, defaced with egg covers and have reduced viability. Heavy attack causes severe powdering and weight loss. In Nigeria, about 30–60% loss in cow pea is attributed to infestation and damage by bruchid beetles over a 3- to 6-month storage period, of which over 90% is caused by C. maculatus alone (Caswell, 1981).
Further effects of manurial treatments on yield, composition and nutrient uptake of potato tubers, and on soil properties (1976–9)
Authors: Sharma R. C. , Grewal J. S.
Published: March 2009

The efficient use of fertilizers is important because fertilizers are one of the costliest inputs in crop production. Compared with N fertilizers, P and K fertilizers are subject to less leaching and leave sufficient residues in the soil, which are utilized by the succeeding crop. Thus a knowledge of the residual effects of P and K fertilizers is essential when formulating a fertilizer programme. In order to test the 1st year residual as well as longer-term effects of P, K and farmyard manure (FYM) on tuber yield and soil properties, a manurial experiment was started in 1970 on an acid hill soil at Fagu, Shimla representing the North Western Himalayan hills of India, at an elevation of 2500 m above sea level. The results of the experiment from 1970 to 1975 have been reported by Sharma, Grewal & Singh (1980) and the results from 1976 to 1979 are reported in this paper.
Photochemical quenching of chlorophyll fluorescence and drought tolerance in different durum wheat (Triticum durum) cultivars
Authors: Flagella Z. , Pastore D. , Campanile R. G. , Fonzo N. Di
Published: March 2009

The aim of this study was to identify a fluorescence parameter whose estimate could be used reliably for a drought tolerance test in durum wheat (Triticum durum). Twenty-five cultivars were grown in a glasshouse over two seasons (1987/88 and 1988/89) at Foggia, Southern Italy. Photochemical and non-photochemical quenching (qQ and qE), the half time of fluorescence decay (tP½) and the initial slope of fluorescence decay (ISPS) were measured on control and dehydrated pre-darkened excised leaves; qQ and qE were measured twice: first at 14 s after actinic illumination and second at the steady state.

No great difference in qQ and qE was apparent between control and dehydrated leaves at the steady state; however, at 14 s after illumination there was a decrease in qQ and in ISPS and an increase in tP½ in dehydrated leaves. The predictive capability of fluorescence parameters was assessed by comparison with a yield-based drought susceptibility index (DSI). The percentage decrease in qQ at 14 s showed the highest correlation with DSI (r = 0·75, significant at P < 0·001), so it may be considered a good indicator of drought tolerance in durum wheat. Results obtained at different developmental stages with different fluorescence levels (Fo, P and Fm) and parameters (qQ, qE and tP½) indicated that for maximum reliability the test must be applied at the vegetative phase.
Concentration and availability to sheep of N, P, K, Ca, Mg and Na in chickweed, dandelion, dock, ribwort and spurrey, compared with perennial ryegrass
Authors: Wilman D. , Derrick R. W.
Published: March 2009

The concentrations of water-soluble carbohydrate, N, nitrate-N, P, K, Ca, Mg and Na were determined in six plant species: chickweed (Stellaria media (L.) Vill.), dandelion (Taraxacum officinale Weber), dock (Rumex obtusifolius L.), ribwort (Plantago lanceolata L.), spurrey (Spergula arvensis L.) and perennial ryegrass (Lolium perenne L.). Field crops of these species were grown at Aberystwyth in 1985,1986 and 1987. In 1985 and 1986 the rumen contents and faeces of lambs fed artificially dried diets of the different species were analysed for N, P, K, Ca, Mg and Na. The intake, apparent availability and, in 1986, retention of each element by the lambs on each diet were calculated.

The results illustrate the potential of dicotyledonous species to extend the range of concentration of some major elements beyond that normally found in temperate grasses. Chickweed was particularly high in P and K, dandelion in K and Mg, dock in Mg, ribwort in Ca and spurrey in Mg and Na. The apparent availability of the elements studied was as high in chickweed, dandelion and spurrey as in ryegrass. The apparent availability of N and P was lower in dock and ribwort than in ryegrass, possibly due to heat damage during drying. All five dicotyledonous species had a higher Mg concentration in herbage than ryegrass (c. 70% higher, on average) and all led to a higher Mg concentration in rumen contents than ryegrass (c. 70% higher, on average). Retention of Mg was three times as great, on average, in sheep fed dicotyledonous diets as in sheep fed ryegrass. The concentration of water-soluble carbohydrate was lower in the dicotyledonous species than in ryegrass. The concentration of nitrate-N was rather high in ribwort when harvested at a leafy stage in October. Dock was moderately low in nitrate-N, despite a rather high concentration of total N.
The pattern of reproductive development and the leafiness of spring and early summer regrowths in two contrasting varieties of ryegrass
Authors: Davies Ieuan
Published: March 2009

Early stages in the development of reproductive tillers of S. 24 and S. 23 perennial ryegrass are described. The pattern of development of the stem apex and of the unemerged leaves present at the time of floral initiation is traced up to the time when internode extension results in the elevation of the stem apices above the level of defoliation. If tillers with stems about 10 cm long, or more, escape damage to the stem apex during defoliation, the regrowth may be expected to deteriorate rapidly in leafiness, since at this stage there are few or no unemerged leaves. Tillers with 3–4 cm stems generally bear 1–2 unemerged leaves, and hence the regrowth is more leafy.

For a given stem length apical development was slightly more advanced in S. 24 than in S. 23. Consideration is given to selection methods to be used in breeding for leafy regrowths in springtime.
Flavour differences in meat from sheep grazed on pasture or winter forage crops
Authors: Park R. J. , Spurway R. A. , Wheeler J. L.
Published: March 2009

Merino wethers grazed pure stands of rape, vetch or oats for 76 days in 1969 and 35 days in 1970. A laboratory taste panel found that the flavour characteristics of meat from these sheep differed significantly from those of meat from similar sheep grazing ryegrass-white-clover pasture or native pasture.

Grazing on rape often produced a meat with a nauseating aroma and flavour, and with significantly lower acceptability of flavour than the pastures. There was no significant difference in the acceptability of flavour of meat from pasture and vetch fed sheep, although vetch gave an intense meaty flavour. Meat from sheep grazing oats possessed a pungent odour and flavour, but with a flavour only slightly, but significantly, less acceptable than that of meat produced on pasture.
Effects of dietary deficiencies of energy, protein and calcium on the pregnant ewe. II. Body composition and mineral content of the lamb
Authors: Sykes A. R. , Field A. C.
Published: March 2009

The effects of low protein and low Ca intakes during pregnancy on lamb composition and mineral contents have been investigated. Twenty-eight 6½-year-old Blackface ewes were used in a 2 × 2 experiment in which semi-purified diets containing 11·8 and 6·0% crude protein and 1·2 and 0·11 % Ca in the dry matter were offered to maintain constant levels of non-esterified fatty acids (NEFA) and ketone bodies in the plasma, comparable to those found in hill sheep in winter. A further group, control, were fed a conventional diet containing adequate crude protein and Ca to maintain NEFA and ketone body levels typical of well-nourished sheep. The lambs were killed at birth and whole body fat, moisture, nitrogen, Ca, P, Mg, Na and K contents determined. Further data was obtained on the brain, liver and semitendinosus muscle.

Within the context of the experiment the most important factor in determining the mineral content of the lambs was the protein intake of the ewe, mainly due to its effect on lamb body weight. The mean Ca content of lambs from the control ewes was 47·8 g. By comparison that of lambs from the high and low protein groups was reduced by 4·9 and 12·9 g respectively.

Calcium intakes as low as 27 mg/kg ewe body weight/day had no significant effect on lamb birth weight or mineral composition.

The mean concentrations (g/kg) of minerals in the fat-free bodies of the lambs ranged from 12·1 to 14·6 for Ca, 6·6 to 7·4 for P, 0·49 to 006 for Mg and from 1·9 to 1·6 for K in the control and double deficiency groups respectively. It was concluded that these changes in lamb composition could be interpreted according to classical studies on the influence of undernutrition on the relative growth and development of animal tissues.

The livers of the lambs, although significantly reduced in weight by the protein deficiency showed no evidence of being relatively more severely affected than muscle tissue.
Effects of dietary deficiencies of energy, protein and calcium on the pregnant ewe. III. Some observations on the use of biochemical parameters in controlling energy undernutrition during pregnancy and on the efficiency of utilization of energy and protein for foetal growth
Authors: Sykes A. R. , Field A. C.
Published: March 2009

Twenty-eight 6½-year-old Scottish Blackface ewes were used in a 2 × 2 factorial experiment and given semi-purified diets containing 11·8 or 6·0% crude protein (CP) and 1·2 or 0·11 % calcium (Ca) in the dry matter (DM). The amounts of diet offered were adjusted to maintain non-esterified fatty acids (NEFA) and ketone bodies in the plasma at levels comparable to those found in hill sheep in winter. Mean group values of NEFA during the final 6 weeks of pregnancy were maintained at these levels (1100–1300 μ-equiv/1) and ketone bodies at approximately 4·8 mg/100 ml. A further six sheep were fed a conventional diet containing adequate CP and Ca, to maintain NEFA and ketone bodies at levels typical of well-nourished sheep. Ewes and lambs from the undernourished groups were slaughtered after parturition and the chemical compositions of their bodies and those of six ewes slaughtered at the commencement of the experiment determined.
Statistical research on the digestibility in the cow. II. Nitrogen and ether extract
Authors: Paquay R. , de Baere R. , Lousse A.
Published: March 2009

The results obtained for nitrogen and ether extract digestibility with 116 different rations fed to 242 non-pregnant dry cows and 96 lactating cows were studied.

A hyperbolic relation exists between nitrogen digestibility (Y) and crude protein content (X), with the equation:

Y = 88·6–(301/X)(r = – 0·928**, RSD = 4·78).

Digestible protein content ( Y) is linearly related to crude protein content(X):

Y = 0·90X-3·10 (r = 0·982**, RSD = 0·823).

From dry-matter intake and crude protein content it is possible to estimate accurately the amount of digestible nitrogen. With all the experimental rations the mean metabolic faecal nitrogen was 496 mg/100 g of ingested dry matter, and the true nitrogen digestibility was conspicuously constant up to 90%.

Digestibility of ether extract depends on the nature of the feeds. When the concentrate percentage of the ration is high, the digestibility of ether extract obeys the same laws as that of nitrogen.
Production of root axes and leaf elongation in perennial ryegrass in relation to dryness of the upper soil layer
Authors: Troughton A.
Published: March 2009

During a period without rainfall the upper layers of the soil may become dry whilst the lower layers provide sufficient moisture for the plant to continue growing. In experimental conditions simulating such a soil environment, new main root axes ceased to be produced by plants of perennial ryegrass. Shoot growth and leaf elongation rate were little affected during the first 2 weeks of the treatment. The subsequent introduction of moisture round the base of the plant resulted in the rapid production of new root axes and increase in the leaf elongation rate. Although there was considerable intra-varietal genetic variation in the rate of development of new root axes and leaf elongation after wetting it is concluded that this would be of doubtful value as a selection criterion.
On satisfying the radiation condition in free-surface flows
Authors: BINDER B. J. , VANDEN-BROECK J.-M. , DIAS F.
Published: March 2009

Binder & Vanden-Broeck (2005) showed there are no subcritical or critical solutions satisfying the radiation condition for steady flows past a flat plate. By using a weakly nonlinear analysis, it is shown that such flows exist for a curved plate. Fully nonlinear solutions are computed by a boundary integral equation method, and new nonlinear solutions for supercritical and generalized critical flows past a curved plate are presented.
A free-surface and blockage correction for tidal turbines
Authors: WHELAN J. I. , GRAHAM J. M. R. , PEIRÓ J.
Published: March 2009

The effects of free-surface proximity on the flow field around tidal stream turbines are modelled using actuator disc theory. Theoretical results are presented for a blocked configuration of tidal stream turbines such as a linear array that account for the proximity of the free surface and the seabed. The theoretical results are compared to open channel flow experimental results in which the flow field has been simulated using a porous disc and strip. These results are complemented by more detailed measurements of the performance of a model horizontal-axis turbine carried out in a water flume and a wind tunnel. The two sets of experiments represent highly blocked and effectively unblocked cases, respectively. The theoretical model of the effects of free-surface proximity provides a blockage correction for axial induction that can be incorporated in blade element momentum codes. The performance predictions obtained with such a code are in good agreement with the experimental results for CP and CT at low tip-speed ratios. The agreement weakens with increasing tip-speed ratio, as the wake of turbine enters a reversed flow state. A correction following the philosophy of Maskell is applied to CT in this region, which provides a better agreement.
Global stability of a jet in crossflow
Authors: BAGHERI SHERVIN , SCHLATTER PHILIPP , SCHMID PETER J. , HENNINGSON DAN S.
Published: March 2009

A linear stability analysis shows that the jet in crossflow is characterized by self-sustained global oscillations for a jet-to-crossflow velocity ratio of 3. A fully three-dimensional unstable steady-state solution and its associated global eigenmodes are computed by direct numerical simulations and iterative eigenvalue routines. The steady flow, obtained by means of selective frequency damping, consists mainly of a (steady) counter-rotating vortex pair (CVP) in the far field and horseshoe-shaped vortices close to the wall. High-frequency unstable global eigenmodes associated with shear-layer instabilities on the CVP and low-frequency modes associated with shedding vortices in the wake of the jet are identified. Furthermore, different spanwise symmetries of the global modes are discussed. This work constitutes the first simulation-based global stability analysis of a fully three-dimensional base flow.
Resource allocation and health technology assessment in Australia: Views from the local level
Authors: Gallego Gisselle , van Gool Kees , Kelleher Dianne
Published: March 2009

Objectives:Several studies have shown that a key determinant of successful health technology assessment (HTA) uptake is a clear, fair, and consistent decision-making process for the approval and introduction of health technologies. The aim of this study was to gauge healthcare providers' and managers' perceptions of local level decision making and determine whether these processes offer a conducive environment for HTA. An Area Health Service (AHS) aimed to use the results of this study to help design a new process of technology assessment and decision making.

Methods:An online survey was sent to all health service managers and healthcare providers working in one AHS in Sydney, Australia. Questions related to perceptions of current health technology decisions in participants' own institution/facility and opinions on key criteria for successful decision-making processes.

Results:Less than a third of participants agreed with the statements that local decision-making processes were appropriate, easy to understand, evidence-based, fair, or consistently applied. Decisions were reportedly largely influenced by total cost considerations as well as by the central state health departments and the Area executive.

Conclusions:Although there are renewed initiatives in HTA in Australia, there is a risk that such investments will not be productive unless policy makers also examine the decision-making contexts within which HTA can successfully be implemented. The results of this survey show that this is especially true at the local level and that any HTA initiative should be accompanied by efforts to improve decision-making processes.
War and garrison towns in the Dutch Republic: the cases of Gorinchem and Doesburg (c. 1570–c. 1660)
Authors: VERMEESCH GRIET
Published: March 2009

This article examines three important aspects of how the Dutch Republic organized warfare during the Dutch Revolt. The regulations for the billeting of soldiers, the building of fortifications and the collection of direct taxes are analysed in two garrison towns, namely, Gorinchem and Doesburg. The billeting of soldiers and the collection of taxes usually caused troubles in neighbouring countries. In comparison to more centralized neighbouring countries, the Dutch polity's decentralized nature, in which cities held positions of strong power, entailed better arrangements for billeting and higher tax compliance. Yet this decentralized nature did not hamper the emergence of central administrative bodies for co-ordinating and organizing the building of fortifications. The Dutch account of organizing warfare challenges existing views about the role of cities in state building within a context of protracted warfare.
Controlling corruption: regulating meat consumption as a preventative to plague in seventeenth-century London
Authors: DOREY MARGARET
Published: March 2009

Seventeenth-century medical theory saw epidemic diseases like the plague as being caused by stinking miasmas resulting from putrefying matter polluting the air. The butchers' trade was singled out in London as a major polluter, implicated in both the regulatory literature and popular images as corrupting both the physical and moral health of the City and its citizens. Controlling the food trades, especially the butchers', was therefore an essential part of containing environmental pollution and preventing disease.
Between anxiety and admiration: views of British cities in Germany, 1835–1914
Authors: LEES ANDREW
Published: March 2009

Examination of writings about British cities that appeared in Germany between the mid-1830s and 1914 runs counter to emphasis either on German anti-urbanism or on growing hostility among Germans to their neighbours across the North Sea. Although it takes into account strong disparagement of flaws and failings that had, in the view of critics, resulted from the chaotic nature of urban growth in Britain, it points to increasing recognition – particularly after mid-century – of efforts to ameliorate conditions about which critics had complained. Much of what was singled out for commendation involved voluntary efforts by men and women who sought to improve working-class life via philanthropic uplift. During the 1850s and 1860s, the conservative social reformer Victor Aimé Huber sang the praises of the co-operative movement, both from an economic and from a moral standpoint. Later on, other observers, such as the liberal economist Gerhart Schulze-Gävernitz, lauded the most famous of the British settlement houses, Toynbee Hall in East London, on account of the activities it promoted in the area of adult education. Favourable commentary on municipal government rounded out a picture of the urban scene as a sphere in which local forces exemplified a spirit of civic-mindedness that ought to inspire admiration rather than enmity.
‘Calculating class’: housing, lifestyle and status in the provincial English city, 1900–1950
Authors: HAYES NICK
Published: March 2009

The multifarious ‘objective’ indicators used to place individuals by class (for example, occupation, wealth, income), or proxies thereof, capture only a part of who we are. More important is our ‘style of life’: our tastes, how we spend what we earn and how this interplays socially to include or exclude us from ‘society’. Of these the most significant cultural site was an individual's house and home, against which, using local property tax records, we can place a defined numeric value. This article analyses class in relation to housing and property values in Nottingham in the first half of the twentieth century.
Sustainable development with stock pollution
Authors: HEDIGER WERNER
Published: March 2009

Optimal pollution control is an important challenge for sustainable development with three distinct cases. First, the situation where nature's assimilative capacity is completely destroyed involves normative problems that require further research. Second, environmental restoration with initial pollution above the steady-state stock requires an economy to initially allocate a relatively high share of its resources to cleaning-up activities. In return, this generally results in an intertemporally efficient development path that is both environmentally and economically sustainable. Third, optimal trajectories in situations with initial stocks of pollution below the long-term optimum generally imply an increase in pollution and a decline of optimal consumption. In this case, the investment of the environmental rents accruing from nature's assimilative capacity into man-made capital is required in analogy to the famous Hartwick rule to maintain a constant flow of instantaneous welfare. This would facilitate growth in consumption sufficient to compensate for the rising disutility of pollution.
On the Dimensional Structure of Personality, Ideological Beliefs, Social Attitudes, and Personal Values
Authors: von Collani Gernot , Grumm Mandy
Published: March 2009

In this paper, the common dimensional-structure of measures of Big Five personality, social attitudes, personal values, conservatism, and ideological beliefs (right-wing authoritarianism and social dominance orientation) was investigated in two convenience samples of adults (Study 1, paper-and-pencil, N = 302; Study 2, Internet, N = 154). A principal components analysis resulted in a three-factor solution in both samples. In particular, a strong ideology factor emerged that can be interpreted as representing an ideological belief system. It is characterized by a right-wing, conservative orientation, social prejudice, ideological beliefs, the value orientations of self-enhancement, low self-transcendence, and the personality trait of low Openness to Experience. The other two factors comprised socially desirable personality traits and values, and a blend of personality and personal-value orientations characterized by energy, activity, openness, and curiosity, respectively. The results are interpreted in relation to recent structural and process models of personality, ideological beliefs, and social attitudes.
Personality as Predictor of Achievement
Authors: Hartmann Peter , Larsen Lars , Nyborg Helmuth
Published: March 2009

General intelligence, g, is a powerful predictor of education, job status and income, but the predictive power of personality is less clear. The objective of the present paper was to investigate the predictive power of personality (and g) with respect to education, job status, and income. We derived Eysenckian personality factors (P, E, N, L) from MMPI data; g was distilled from a large number of highly diverse cognitive variables. Linear, nonlinear, and interaction power in predicting socioeconomic achievement in 4200+ middle-aged American males was tested. In the present study, broad personality factors provided little incremental validity to g, in predicting socioeconomic achievement across type of education and job categories. This is at odds with previous studies, and does not exclude the possibility that certain personality factors (higher or lower order) have more predictive validity within certain job categories and education types.
States vs. Traits
Authors: Hagemann Dirk , Naumann Ewald
Published: March 2009

Hans-Jürgen Eysenck suggested that introverts are characterized by greater cortical arousal or arousability than extraverts. This prediction was tested in several studies that used the electroencephalogram (EEG) to index cortical activity, but the relations between the EEG measures and Extraversion are typically small. Possibly, situational factors that are external to the laboratory may act as nuisance variables and affect cortical activity, thus, mitigating the relation between arousal or arousability and Extraversion. To test this hypothesis, resting EEG was acquired on four occasions of measurement and Extraversion was assessed by questionnaire. A structural equation model (SEM) represented cortical arousal, arousability, and external factors. This analysis suggested that (1) arousal and arousability are independent factors, (2) external factors only marginally contribute to the variance of the EEG measures, and (3) the relations between the EEG measures and Extraversion were insignificant even if external factors were statistically controlled.
Reproducibility of minor and trace element determinations in Porites coral skeletons by secondary ion mass spectrometry
Authors: Allison Nicola , Finch Adrian A.
Published: March 2009

Secondary ion mass spectrometry (SIMS) can be used to analyze selectively the geochemistry of pristine structures in diagenetically altered fossil corals allowing accurate reconstruction of past climates. However, only a small fraction of the aragonite precipitated by a single coral polyp is analyzed by SIMS. We evaluate the reproducibility of SIMS‐generated Sr/Ca, Mg/Ca, and Ba/Ca records, both within and between modern corals. We find no evidence that crystal orientation in the analyzed volume affects these determinations. Corals are heterogeneous with respect to Sr, Mg, and Ba (at the scale analyzed by SIMS) and we are unable to correlate the trace and minor element variations observed between individual analyses along two parallel transects in the same coral. We observe good agreement in mean Sr/Ca and Ba/Ca between SIMS transects analyzing skeleton deposited over comparable periods, both within and between coral skeletons of comparable growth rates. Our data indicate that SIMS analysis can be used to produce a reproducible estimate of skeletal Sr and Ba both within and between corals. We observe good agreement in mean Mg/Ca between parallel SIMS transects within a coral but significant differences in the mean Mg/Ca between different corals. The typical error (2σ) of 100 SIMS Sr/Ca analyses across single annual bands of modern Hawaiian corals is equivalent to an SST error of ±0.6°C under the conditions used here.
Locations and types of ruptures involved in the 2008 Sichuan earthquake inferred from SAR image matching
Authors: Kobayashi Tomokazu , Takada Youichiro , Furuya Masato , Murakami Makoto
Published: March 2009

We have detected detailed ground displacements in the proximity of the Longmen Shan fault zone (LMSFZ) by applying a SAR offset‐tracking method in the analysis of the 2008 Sichuan earthquake. An elevation‐dependent correction is indispensable for achieving sub‐meter accuracy. A sharp displacement discontinuity with a relative motion of ∼1–2 m appears over a length of 200 km along the LMSFZ, which demonstrates that the main rupture has proceeded on the Beichuan fault (BF) among several active faults composing the LMSFZ, and a new active fault is detected on the northeastward extension of the BF. The rupture on the BF is characterized by a right‐lateral motion in the northeast, while in the southwest an oblique right‐lateral thrust slip is suggested. In contrast to the northeast, where a major rupture proceeded on the BF only, in the southwest multiple thrust ruptures have occurred in the southeastern foot of the Pengguan massif.
Effect of aqueous and carbonic fluids on the dislocation creep strength of quartz
Authors: Chernak Linda J. , Hirth Greg , Selverstone Jane , Tullis Jan
Published: March 2009

Dislocation creep experiments conducted on quartzite indicate that the presence of CO2 can cause strengthening or weakening depending on the oxygen fugacity of the deformation environment. Under oxidizing conditions (ferrosilite‐hematite‐quartz), the presence of CO2 reduces the water fugacity and results in strengthening of the quartz. Under moderately reducing conditions (∼Ni‐NiO), CO2 reacts with H2 from the sample assembly to form graphite; the water produced by this reaction causes weakening. Under extremely reducing conditions (quartz‐fayalite‐iron), CO2 is reduced to methane, a reaction that consumes original water, thereby increasing the strength of quartz. Our results show that increasing at constant confining pressure, by changing fluid composition, has a similar effect as increasing by increasing confining pressure. The exponent suggested by our data for the dislocation creep flow law is 0.375 to 1 (assuming a stress exponent of 3 to 4), which is on the low side of previously reported values. Differences in deformation behavior over small length scales may thus be related to local differences in the that effectively change the in the presence of CO2.
Riser diachroneity, lateral erosion, and uncertainty in rates of strike‐slip faulting: A case study from Tuzidun along the Altyn Tagh Fault, NW China
Authors: Gold Ryan D. , Cowgill Eric , Arrowsmith J Ramón , Gosse John , Chen Xuanhua , Wang Xiao‐Feng
Published: March 2009

At late Quaternary timescales, offset fluvial terrace risers are among the most common landforms used to determine rates of strike‐slip faulting. Although diachroneity in the age of riser segments on opposite sides of the fault has been noted previously, an unexplored source of uncertainty associated with deriving slip rates from these markers centers on quantifying the size of the displacement uncertainty such diachroneity introduces. To evaluate the impact of riser diachroneity, we investigated the Tuzidun site (37.73°N, 86.72°E) along the Cherchen He reach of the active central Altyn Tagh Fault. The east bank of the channel is flanked by a left‐laterally offset terrace riser. While the measured offset is 54 ± 3 m, geochronologic measurements and analysis of riser topography indicate that the downstream riser segment formed between 6.0 ± 0.8 ka and 5.7 ± 0.4 ka, while the upstream riser segment may have been laterally refreshed as recently as 0.5 ± 0.2 ka. A valley wall on the west bank of the channel places a maximum limit of 38 ± 6 m on the amount of possible lateral erosion of the upstream riser. This bound, in turn, limits the total offset since formation of the downstream riser to range from 54 ± 3 to 89 ± 7 m. Together, these observations bracket the millennial Altyn Tagh Fault slip rate to range from 9.0 ± 1.3 to 15.5 ± 1.7 mm a−1. More generally, this investigation shows that the observed riser displacement does not necessarily correlate with the age of either riser segment (downstream or upstream of the fault) in cases where one segment is displaced while the other is subjected to lateral erosion. If this diachroneity goes undetected, erroneous slip rate measurements are likely to result.
Toward an estimation of global land surface heat fluxes from multisatellite observations
Authors: Jiménez Carlos , Prigent Catherine , Aires Filipe
Published: March 2009

The sensitivity of a suite of satellite observations to land surface heat fluxes and the estimation of satellite‐derived fluxes using a statistical model are investigated. The satellite data include visible and near‐infrared reflectances (Advanced Very High Resolution Radiometer [AVHRR]), thermal infrared surface skin temperature and its diurnal cycle (International Satellite Cloud Climatology Project [ISCCP]), active microwave backscatter (European Remote‐sensing Satellite [ERS] scatterometer), and passive microwave emissivities (Special Sensor Microwave/Imager [SSM/I]). Fluxes at the global scale are taken from Land Surface Models (LSM): the GSWP‐2 multimodel analysis, the ISBA, and ORCHIDEE participating models, along with the National Centers for Environmental Prediction/the National Center for Atmospheric Research (NCEP/NCAR) reanalysis, on a monthly timescale from 1993 to 1995. The simulated LSM fluxes and the satellite observations are linked through a statistical model. Once calibrated, the statistical model reproduces the LSM latent and sensible fluxes for all types of snow‐free environments, with global RMS errors <25 W/m2, proving that the satellite data contain relevant information for flux estimation. The estimated fluxes have realistic spatial and seasonal patterns, although some local differences between the original and estimated fluxes are found. These differences are used to reveal potential problems in the LSMs, for instance, an anomaly in the GSWP‐2 radiative forcings. Comparisons between the original and estimated fluxes and 76 tower fluxes over North America are carried out, and the differences show similar statistics. However, the largest differences between the original and estimated fluxes do not occur in these regions. Demonstrating the superiority of the proposed technique outside of these regions remains difficult in the absence of validation data sets.
Observations of periglacial landforms in Utopia Planitia with the High Resolution Imaging Science Experiment (HiRISE)
Authors: Lefort A. , Russell P. S. , Thomas N. , McEwen A. S. , Dundas C. M. , Kirk R. L.
Published: March 2009

The region of western Utopia Planitia (80–105°E, 40–55°N) displays several types of landforms similar to Earth periglacial features, including scallop‐shaped depressions and networks of polygonal terrains. The scalloped depressions have been proposed to originate from thermokarstic processes such as sublimation and/or melting of near‐surface ground ice. Using HiRISE imagery, we characterize these depressions and several associated, distinct polygon networks in unprecedented morphologic and topographic detail and investigate support for an ice‐based degradation process. The scalloped depressions and interior polygons and ridges are found to evolve together, mainly influenced by sublimation, local proximity of ground ice to the surface, and obliquity variations.
Regionally compartmented groundwater flow on Mars
Authors: Harrison Keith P. , Grimm Robert E.
Published: March 2009

Groundwater flow on Mars likely contributed to the formation of several types of morphologic and mineralogic features, including chaotic terrains, valley networks, Meridiani Planum geologic units and, potentially, sulfate and phyllosilicate deposits. A central issue for these features is the spatial scale of groundwater flow required for their formation. For groundwater simulation purposes, a global Martian aquifer has frequently been assumed, but the validity of this assumption has not been tested. Chaotic terrains, thought to have formed owing to the disruption of a cryosphere under high aquifer pore pressures, provide the basis for such a test. Specifically, we use groundwater models to predict regions of cryosphere disruption due to recharge‐driven pore pressure increases, and we compare these regions to observed Martian chaotic terrains. Our results suggest that a globally connected aquifer cannot give rise to cryosphere disruption at the two locations where large chaotic terrains are observed (the circum‐Chryse region and the eastern Hellas Planitia). Conversely, modeled cryosphere disruption occurs in locations such as Amazonis Planitia and west Hellas Planitia where no supporting evidence is present, suggesting again that groundwater flow was likely regionally compartmented. Furthermore, the consistent occurrence of modeled breakouts in the Valles Marineris canyon system suggests that large‐scale fractures there likely discharged most of the groundwater required for circum‐Chryse outflow channel formation, with only minor contributions from chaotic terrains. The fractures are close to a likely source of recharge over Tharsis, and their low elevations lead to high pore pressures even if groundwater flow is regionally compartmented.
Morphodynamic regime and long‐term evolution of meandering rivers
Authors: Frascati Alessandro , Lanzoni Stefano
Published: March 2009

In the present contribution we focus our attention on the long‐term behavior of meandering rivers, a very common pattern in nature. This class of dynamical systems is driven by the coexistence of various intrinsically nonlinear mechanisms which determine the possible occurrence of two different morphodynamic regimes: the subresonant and the superresonant regimes. Investigating the full range of morphodynamic conditions, we objectively compare the morphologic characteristics exhibited by synthetically generated and observed planimetric patterns. The analysis is carried out examining, through principal component analysis, a suitable set of morphological variables. We show that even in the presence of the strong filtering action exerted by cutoff processes, a closer, although not yet complete, similarity with natural meandering planforms can be achieved only by adopting a flow field model which accounts for the full range of morphodynamic regimes. We also introduce a new morphodynamic length scale, m, associated with spatially oscillating disturbances. Once normalized with this length scale, the relevant morphologic features of the simulated long‐term patterns (e.g., the probability density function of local curvature and the geometric characteristics of oxbow lakes) tend to collapse on two distinct behaviors, depending on the dominant morphologic regime.
Stochastic analysis of transport in a combined heterogeneous vadose zone–groundwater flow system
Authors: Russo David , Fiori Aldo
Published: March 2009

First‐order analysis was used to investigate the effect of a few characteristics of the vadose zone and the solute source at the soil surface on the expected breakthrough curves (BTCs) of tracer solutes in a combined unsaturated‐saturated spatially heterogeneous formation with a three‐dimensional, statistically anisotropic structure. The analysis is based on a stochastic continuum representation of the stationary and nonstationary Eulerian velocity vectors in the unsaturated and saturated domains, respectively, and a general Lagrangian description of the solute mass flux in steady state flow. Results of the present analysis suggest that the length scales and the flow characteristics of the spatially heterogeneous, unsaturated zone that affect the travel time probability density function between the soil surface and the water table also affect the expected solute BTC at a control plane located downstream in the groundwater. The flow in the unsaturated zone might enhance the early arrival time and the spreading of the expected solute BTC in the groundwater, especially when the vertical extent of the unsaturated zone is relatively large; when the unsaturated zone consists of relatively dry, coarse‐textured, stratified soil material; and when the horizontal extent of the solute source in the direction of the mean groundwater flow is relatively large. The effect of the characteristics of the vadose zone and the solute source at the soil surface on the expected solute BTC in the groundwater decreases as the distance to the control plane increases and as the process of the solute breakthrough is more advanced. The relatively good agreement between the results of the present first‐order, stochastic analysis with the results of detailed, numerical analyses of flow and transport in a three‐dimensional heterogeneous, combined vadose zone–groundwater flow domain suggests that the first‐order stochastic analyses may be sufficiently reliable to show appropriate trends which might occur in realistic combined vadose zone–groundwater flow systems.
Simple physics‐based predictor for the number of river bars and the transition between meandering and braiding
Authors: Crosato Alessandra , Mosselman Erik
Published: March 2009

The number of bars that form in an alluvial channel cross section can be determined from a physics‐based linear model for alluvial bed topography. The classical approach defines separators between ranges in which river planform styles with certain numbers of bars are linearly stable and linearly unstable. We propose an alternative method that is easier to apply. Instead of defining separators between stable and unstable conditions for certain river planform styles, the method directly estimates the most likely number of bars. It is based on a demonstration that conditions of zero spatial damping in a linear model for steady bars are representative for the bar mode that develops inside a river channel. We argue that a method based on steady bars is more appropriate for real rivers than a method based on free migrating bars. We verified the method by applying it to several existing rivers at bankfull conditions. The results are good for width‐to‐depth ratios up to 100 but deteriorate for higher width‐to‐depth ratios. We explain the deficiencies for large width‐to‐depth ratios from the linearity of the model. The results show that our method can be used as a reliable predictor for whether reducing or enlarging the width of a river will lead to a meandering, transition, or braided planform.
Is transmissivity a meaningful property of natural formations? Conceptual issues and model development
Authors: Dagan G. , Lessoff S. C. , Fiori A.
Published: March 2009

At regional scale, it is common to model groundwater flow as 2‐D in the x, y, horizontal plane, by integrating the full 3‐D equations over the vertical. Furthermore, adopting the Dupuit assumption results in the local transmissivity T as a formation property, equal to the vertically integrated hydraulic conductivity K. In practice, the related block transmissivity Tb, defined for a volume of area ω (square of side L) in the horizontal plane and height D, is the property of interest. However, most aquifers are of a heterogeneous 3‐D structure, and Y = lnK is commonly modeled as a normal and stationary random function which is characterized by the variance σY2, the horizontal I, and vertical Iv integral scales. The Dupuit assumption is generally not obeyed for formations of 3‐D spatially variable Y, and transmissivity is no more a meaningful property, independent of flow conditions. Useful generalizations of local and block transmissivity are possible for steady mean uniform flow in the horizontal direction and formations of constant thickness. In that case T and Tb become random stationary variables characterized by their mean, variance, and integral scales. These moments are determined for the first time in an analytical form or by a few quadratures, by adopting a first‐order approximation in σY2, and they depend on the ratio D/Iv, e = Iv/I and L/I. The block conductivity expected values are compared with the numerical solutions of Dykaar and Kitanidis (1993), and the agreement is very good for σY2 ≤ 1. The main conclusion of the study is that for this simple flow configuration and for common parameter values, Tb is practically deterministic and equal to Keff(e) D, where Keff is the effective conductivity in uniform flow in an unbounded formation. At regional scale, Tb may be regarded as a local property which changes slowly in the horizontal plane. Analysis of numerous field data shows that this variation is also random and characterized by integral scales Ireg, of the order of kilometers. The separation of scales makes possible to regard the local Tb, as determined along the lines of the present study in a support volume of extent of a few D, as a point value at the regional scale. Practical implications and topics for future investigations are outlined.