bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of substrate concentration on the induction of amidases in herbicide degradation
Authors: Lechner U. , Straube G.
Published: July 2010

Two bacteria which are able to hydrolyze phenylamide herbicides show differences in the induction of amidases at very low inducer concentrations. In the strain 28/1 no amidase activity could be found at inducer concentrations below 0.01 to 0.05 mm in dependence on the inducer.

In the strain Rhodococcus spec. b3 a low level of a constitutive amidase was observed. With increasing inducer concentration from 0.001 to 0.5 mm an increasing amidase activity was measured.
Climate regionalization and rotation of principal components
Authors: White Dale , Richman Michael , Yarnal Brent
Published: July 2010

Climate regionalization studies have made intensive use of eigenvector analysis in recent literature. This analysis provides a motivation for examination of the efficacy and validity of variations of principal component analysis (PCA) for such tasks as an eigenvector‐based regionalization. Specifically, this study applies the results of an earlier statistical comparison of rotational schemes to monthly Pennsylvanian precipitation data (1958–1978) to analyse differences among the various solutions. Unrotated, orthogonally rotated, and obliquely rotated solutions (eight in total) are compared in order to assess the model and locational consistency among and within these solutions. Model correspondence and consistency are measured by a congruence coefficient used to match (i) the principal components (PC) of the total domain for the selected benchmark pattern with PCs from the total domains of the remaining seven solutions, and (ii) each PC of the total domain with PCs of 25 randomly selected subdomain pairs (a set of 10 and 11 years of data). Locational or geographical consistency among the PC patterns is determined by quantifying the changes in area and area boundary defined by a threshold loading.

The results from the Pennsylvanian data indicated that substantial differences in regionalization arose solely from the choice of a particular rotation algorithm, or lack thereof. Oblique rotations were generally found to be the most stable, whereas the orthogonally rotated and unrotated solutions were less stable. The quantitative areal differences among rotation schemes and the unrotated solution illustrate the inherent danger in blindly applying any given solution if physical interpretation of the regionalization is important. The quantitative areal and boundary differences may particularly influence PCA over global spatial domains.
Synoptic aspects of the central chile rainfall variability associated with the southern oscillation
Authors: Rutllant José , Fuenzalida Humberto
Published: July 2010

Central Chile winter (June, July, August (JJA)) rainfall shows positive anomalies during the developing stage of warm events of the Southern Oscillation. Conversely, cold events correspond quite closely to dry conditions.

A synoptic characterization of major storms during the most recent warm events is presented. Dry months during cold‐event years are described in terms of average 500‐hPa contour anomaly fields. Significant departures from this general behaviour are also discussed.

It is found that major winter storms associated with warm events are related to blocking highs frequently located around the Bellingshausen Sea (90°W) within hemispheric circulation anomaly patterns where zonal wavenumbers 4 and 3 dominate. This phenomenon seems consistent with observed teleconnection wavetrains stemming from the anomalous atmospheric heat source above the equatorial Pacific during ENSO events. Cold years, often immediately preceding or following a warm event, bring dry conditions in the study area owing to a well‐developed south‐east subtropical anticyclone with enhanced zonal westerly flow at middle latitudes.

Frequency distributions of 500‐hPa daily blocking indices (BI) at 90°W, derived from 1980 to 1987 European Centre for Medium Range Weather Forecasts hemispheric analyses, show a significant departure towards positive BI values for the available warm‐event winters; the opposite being also true. However, the JJA rainfall variability at Santiago (33.5°S) also seems to be related to the regional strength of the south‐east Pacific anticyclone, as represented by seasonal 500‐hPa geopotential anomalies at Puerto Montt, Chile (41.5°S).
Marine stratocumulus climatologies
Authors: Hanson Howard P.
Published: July 2010

Conditions favourable to the formation and maintenance of marine stratocumulus cloud decks commonly occur in the subtropical latitudes off the west coasts of the major continents. The cloud decks over the eastern North and South Pacific and the eastern South Atlantic are well‐established examples of the phenomenon; the eastern North Atlantic exhibits rather different behaviour. Large‐scale climatological averages based on data extracted from the Comprehensive Ocean‐Atmosphere Data Set are remarkably similar in the three of these regions that exhibit well‐established marine stratocumulus cloud decks. Off the coast of northwest Africa, however, the sea‐surface temperatures are higher and the cloud cover is less overcast than for the other regions.

The correlation between interannual changes in clouds and SST is negative in all four areas: years with lower than normal SST tend to be more cloudy. The implication of this for climate system feedbacks is that these clouds have the potential to exert positive feedback in the climate system. A zero‐order estimate of the strength of this positive feedback suggests that it could be comparable to that due to water vapour in the atmosphere.
Quantitative relationships of mean seasonal precipitation in the Tagus river basin (SPain)
Authors: Egido A. , Egido M. , Seco J. , Garmendia J.
Published: July 2010

The mean precipitation for each of the four season of the year (winter, spring, summer, and autumn) in the Tagus basin was estimated as a function of four geoclimatic parameters characteristics of the zone using data from 161 meteorological stations during an uninterrupted 16‐year period (1970–1985).
The variation of moisture conditions in China during the last 2000 years
Authors: Gong Gaofa , Hameed Sultan
Published: July 2010

Utilizing more than 50,000 reports of droughts and floods found in local records we have reconstructed the history of moisture conditions in eastern China for the last 2000 years. The area studied extends eastward of Gansu province and is situated between Inner Mongolia in the north and Zhejiang in the south. Separate analyses are presented for the semi‐arid, semi‐wet and wet subdivisions of this area. It was possible to develop moisture indices with a time resolution of 5 years in each subregion. The time series of the moisture index presented for the semi‐wet area extends over the period AD 1–1950, while for the other two subregions the period covered is AD 251–1950.

Each of the climatic subdivisions is found to undergo prolonged periods of dryness and wetness. The frequency of alternation between dry and wet conditions increases from the semi‐arid region to the semi‐wet region to the wet region. The variations of moisture conditions in the whole area of eastern China is compared with known changes in the level of the Caspian Sea. The variations in the two regions are found to be coherent.
Tree‐ring reconstructed sunshine duration over central USA
Authors: Stahle David W. , Cleaveland Malcolm K. , Cerveny Randall S.
Published: July 2010

Tree‐ring chronologies of baldcypress (Taxodium distichum) and post oak (Quercus stellata) from the central United States of America are directly correlated with precipitation, and inversely with percentage possible sunshine during the growing season (March‐June). Partial correlation analysis indicates that precipitation is the most important climate signal in the growth of these trees, but sunshine duration accounts for an additional 22 per cent of the radial growth variance independently of the growth influences of precipitation or temperature. Because the internal moisture balance of trees and ultimately the width of annual tree‐rings assimilate the direct and interactive effects of sunshine duration, temperature, and especially precipitation, the tree‐ring chronology can explain 60 per cent of the variance in regional sunshine duration. Consequently, the derived reconstruction retains more sunshine duration information than is reflected by the simple covariance between rainfall, cloud cover, and sunshine. A tree‐ring reconstruction of sunshine duration from AD 1700 to AD 1980 suggests that short‐period changes in the mean, variance, and persistence of cloud cover have occurred over the past 281 years. Analysis of the reconstruction indicates that strong El Niño events are often associated with cloudy growing season conditions over the central USA. The full 281‐year reconstruction and the 85‐year instrumental sunshine data also contain prominent 5‐ to 10‐year sunshine oscillations, which frequently help to induce trends lasting up to 20 years. The sunshine reconstruction does not, however, reveal any statistically significant 30‐year‐long linear trends in sunshine duration since 1700.
The influence of daytime heating and nocturnal cooling on surface airflow patterns over central Japan
Authors: Suzuki Rikie
Published: July 2010

Focus is placed on the two factors that dominate surface airflow patterns; the thermal effect (solar heating and nocturnal cooling) and the synoptic pressure gradient. The relationship between surface airflow patterns and these two factors is investigated, using a dense network of observation sites in central Japan at 0300, 0900, 1500, and 2100 LST over 3 years. The analysis consisted of the construction of 1464 airflow pattern maps, which were then classified using cluster analysis into 15 airflow pattern types. The thermal effect was parameterized by the diurnal component of surface temperature change using a high‐pass filter. The relationship between airflow patterns and the thermal effect was then examined. As a result, detailed relationships between airflow patterns and distributions of heated and cooled areas were statistically revealed. Furthermore, the dependency of airflow patterns on the thermal effect and the synoptic pressure gradient was evaluated, and it was concluded that they were the main factors in controlling the airflow patterns in the majority of cases.
Dust storm frequency in Asia: Climatic control and variability
Authors: Littmann Thomas
Published: July 2010

The dimension and environmental impact of the dust storm phenomenon has been realized only recently. There are few previous works on the climatic control of dust storm frequency, especially in the field of time series analysis. Actually, there is a poor correspondence of climatic parameter mean values and dust storm data. Although generally negative, rainfall — dust‐storm correlations do not reveal the physical causes of dust storm generation, as is shown by lagged cross‐correlation and spectral analysis. Temperature data may indicate seasonal variation of dust storms by extreme values, but they are no reliable defining factor owing to high persistence over shorter time series. The same is found for mean wind speeds, but negative interrelations with atmospheric pressure point to the importance of cyclogenesis and convective cells in dust storm generation in Asia.

Three different seasonality patterns are described: (i) a single dust storm maximum in spring typical of summer rain areas; (ii) a single storm maximum in summer in areas with bimodal (winter and monsoonal) rainfall; (iii) an extended spring and summer dust storm maximum in areas with unimodal winter rains. Additional data from northern Africa fit into this pattern.

Spectral energy of dust storm, rainfall, and temperature series for northern India and northern China (1976–1986) is mainly concentrated in the wavelength of seasonal variations, but some supra‐seasonal signals indicate fluctuations between 3·6 and 5·5 years with various phase dislocations. In China, this interannual variability is supposed to be linked with dynamic shifts in circumpolar vortex dynamics.
Precipitation pegionalization: An application using a meteorological network in catalonia (Ne Spain)
Authors: Periago M. C. , Lana X. , Serra C. , Mills G. Fernàndez
Published: July 2010

Three different precipitation regionalizations based on 80 stations in Catalonia (north‐eastern Spain), with a recording period over the last 50 years, are produced. The first classification is achieved by using monthly average precipitation and some concepts of mathematical information theory applied to precipitation frequency histograms. The clustering procedure is based on an ‘average linkage’ algorithm. The results are discussed in terms of orographic features and rainfall regime and compared with the other two classifications, which are briefly described. One of them is obtained from only monthly average values and the other is based directly on frequency histograms of precipitation. Several reasons lead us to accept the first one, based on monthly average data and information theory, as the best method. Another important aspect of this paper is the definition of the optimal interval amplitude when dealing with precipitation frequency histograms.
Southern hemisphere sea‐level pressure data: An analysis and reconstructions back to 1951 and 1911
Authors: Jones P. D.
Published: July 2010

The reliability of Australian (1972–1985) and NOTOS (1951–1962) gridded monthly mean sea‐level pressure data sets over the Southern Hemisphere (15‐60°S) is examined by comparison with station mean sea‐level pressure data from 77 sites. The station data are used in a principal components regression scheme to reconstruct gridded data back to 1951 and to 1911 using different sets of station data. The reconstructions are best near the continental areas but useful reconstructions are possible near the many ocean islands that have data since 1951. The reconstructions that extend back to 1911 are only useful near the continental areas and over the south‐western Pacific Ocean. The reconstructions are used to compare the Australian, NOTOS data sets and a New Zealand gridded set available for the Southern Hemisphere (60°E‐150°W) since 1954, and to assess changes in the strength of the three subtropical anticyclones and the southern westerlies since 1951.
Atmospheric circulation controls and characteristics of a flood event in central South Africa
Authors: Lindesay J. A. , Jury M. R.
Published: July 2010

Factors contributing to the synoptic‐scale forcing of flood‐producing rainfall over central South Africa in February 1988 are identified as tropical convection over southern Africa, easterly waves and an anticyclone over the south‐west Indian Ocean and Mozambique Channel, and mid‐latitude westerly wave disturbances to the south of Africa. Tropical moisture was advected over southern Africa during this period by barotropic perturbations that originated over the south‐west Indian Ocean as easterly waves. The area of tropical convection was linked to a mid‐latitude westerly wave to the south of the subcontinent by a tropical‐temperate trough and attendant cloud band during the flood episode. The development and persistence of a lower tropospheric anticyclone over the Mozambique Channel during the rainfall event slowed the progress of westerly troughs across the region and contributed to the increased residence time of strong, organized convection over central South Africa. The thermodynamic and kinematic characteristics of the atmosphere over the subcontinent in the presence of the tropical‐temperate trough are typical of enhanced convection in a tropical environment. Distinctive features associated with the presence of the well‐developed tropical‐temperate trough during the flood event are increased westerly relative angular momentum generation around 20°S, the forcing of an anomalous Hadley‐type circulation over eastern southern Africa, strong poleward fluxes of momentum in the upper troposphere, and poleward displacement of the subtropical jet in the region of Marion Island.
Simulations of the USA drought of 1988
Authors: Hunt B. G. , Gordon H. B.
Published: July 2010

A global general circulation model has been used to investigate the impact of the observed sea‐surface temperature anomalies in the Pacific Ocean in 1988. A primary objective was to evaluate the importance and relevance of these anomalies to the 1988 USA drought. A series of experiments was conducted to this end, involving fixed sea‐surface temperature anomalies, seasonally varying anomalies for 1987 and 1988, and seasonally varying anomalies for 1988 alone. In all experiments large‐scale droughts were simulated over parts of the USA. The most realistic experiments, where results are presented in some detail, reproduced the overall spatial and temporal rainfall anomalies observed over North America in 1988 in encouraging detail. The rainfall variations over North America were found to be sensitive to initial conditions, indicating the need to conduct multiple experiments so that composites of results can be derived. No attempt was made to initialize the model experiments with conditions appropriate to January 1988, hence considerable potential exists for improving the realism of the simulations presented here.
Some indications of 18·6 year LUNI‐Solar and 10–11 year solar cycles in rainfall in North‐West India, the plains of Uttar Pradesh and North‐Central India
Authors: Mitra Kumares , Mukherji Subhasish , Dutta S. N.
Published: July 2010

Rainfall data available in the form of books published by the India Meteorological Department for 115 rain‐gauge stations in north‐west India, the Plains of Uttar Pradesh, and north‐central India for the period 1901–1950 have been subjected to maximum entropy spectral analysis (MESA). The results of the analysis indicate that 91 out of 115 rain‐gauge stations appear to respond to 18·6‐year luni‐solar nodal (MN) signal. The statistical average value of the signal periodicity (T̄L) in rainfall proves to be 18·3 + 1·6 years.

Maximum entropy spectral analysis results also appear to indicate the existence of a 10–11‐year solar cycle (Sc) in 77 rain‐gauge stations out of 115. Application of MESA apparently splits the solar signal term, resulting in its absence from the spectral results of some stations and the presence of an 8–9‐year component in almost every station result. The statistical average value of the solar signal periodicity (T̄S) in rainfall proves to be 10·9±0·7 years.
Global warming and regional rainfall: The difference between average and high intensity rainfalls
Authors: Yu B. , Neil D. T.
Published: July 2010

Comparison of rainfall during cold and warm periods within instrumental records has been useful in developing quantitative climate scenarios in the face of prospective global warming. In south‐eastern Australia, it is known that a warm period in the Southern Hemisphere in the latter part of this century coincided with greater rainfall, especially during summer months. In this study, based on daily rainfall data from 17 stations with longest record lengths on the Southern Tablelands, Australia, it is observed that high intensity rainfall does not necessarily follow the same pattern. In fact, the difference between rainfall in a warm and wet and a cold and dry period could decrease as the critical rainfall intensity increases.
Kriging and intraregional rainfall variability in England
Authors: Bigg Grant R.
Published: July 2010

Using a tool of regionalized variable theory, the semi‐variogram, to remove large‐scale trends, the intraregional spatial variability during 1980 of annual, seasonal, monthly, and extreme‐event rainfall is investigated for two contrasting rainfall regimes within the UK. These are hydrological areas within East Anglia and south‐west England. Altitude is shown to be the dominant factor influencing rainfall variability on these temporal scales in South‐west England for space scales of 2–60 km. In East Anglia altitude is again the dominant factor, but in a much more subtle way, for spatial variability on time‐scales of a month or more. This more subtle influence does, however, allow information on storm structure to be obtained for individual rain events, as is illustrated by a case study.
The changing frequency of gales on the swedish west coast and its possible relation to the increased damage to coniferous forests of Southern Sweden
Authors: Franzén Lars G.
Published: July 2010

This paper deals with the frequency of gales on the Swedish west coast over a period of 130 years. The results show that gale frequency was very high in the 1870s and in the 1920s. During the period 1940–1960, relatively few gales were recorded. From about 1970 and onward, the frequency has again risen to very high levels in the late 1980s.

The changing frequency of gales is discussed in connection with the increased damage to coniferous forests observed in southern Sweden over the last two decades. To find possible explanations for the fluctuations in the wind climate, the wind data series were compared with other climatic data and solar radiation variations. Correlation tests and harmonic analyses of the time series investigated indicate the existence of a relationship between seasonal fluctuations of gale frequency, air pressure, air temperature, temperature of surface waters of the sea to the west of Sweden, and solar radiation.
The meteorological control on the anthropogenic ion content of precipitation at three sites in the UK: The utility of lamb weather types
Authors: Davies T. D. , Dorling S. R. , Pierce C. E. , Barthelmie R. J. , Farmer G.
Published: July 2010

Daily observations of concentrations of non‐marine sulphate, nitrate, ammonium, and hydrogen ion in precipitation at three sites in the UK (south‐west England, eastern England, southern Scotland) have been used to attribute proportions of the total annual depositions of these ions to various Lamb Weather Types (LWTs). The LWT classification is a convenient description of the daily atmospheric circulation over the British Isles. In terms of affecting the annual character of total annual deposition of the ions, it is Cyclonic, Westerly, and Anticyclonic weather types that play the dominant roles. These roles vary from station to station. Other LWTs can also play important roles, but there is much site‐to‐site and year‐to‐year variation. The patterns of the relationships for each of the stations are explained in terms of the ‘average’ back‐trajectories from each station for precipitation events associated with each of the major LWTs. It is the relative dispositions of these average trajectories with respect to the major pollutant source regions that allows the use of LWTs as simple tools in the interpretation of precipitation composition. There are indications that atmospheric circulation changes may play a part in the variations of precipitation composition over years to decades.
Monthly mean upper tropospheric humidities in cloud‐free areas from meteosat observations
Authors: van de Berg Leo , Pyomjamsri Angkana , Schmetz Johannes
Published: July 2010

The purpose of this paper is to study the annual variation of the upper tropospheric relative humidity fields extracted from radiance measurements in the water vapour channel (in the thermal infra‐red at wavelengths around 6.3 μm) aboard the geostationary satellite METEOSAT. Monthly mean fields for April, July and October 1988 and January 1989 have been created from the operational Upper Tropospheric Humidity (hereafter UTH) product derived routinely at the European Space Operations Centre (ESOC). The present product retrieval is confined to cloud‐free areas in the upper troposphere, thus the monthly means represent an average over cloud‐free cases.

Principally the patterns of the monthly mean UTH fields reflect the large‐scale circulation of the atmosphere. In the low latitudes, belts with relatively high and low UTH values are located over the ascending and descending branches of the ‘Hadley cell’, respectively. The distinct patterns of monthly mean UTH fields can be used to characterize the geographical structure of the Hadley cell.

The UTH fields complement existing data on atmospheric humidity for use in numerical weather prediction and climatological research. The monthly mean fields presented in this paper may be useful for validating upper tropospheric water vapour fields in climate models.
An examination of atmospheric mechanisms that may be responsible for the annual reversal of the beaufort sea ice field
Authors: Ledrew Ellsworth F. , Johnson Douglas , Maslanik James A.
Published: July 2010

The late‐summer reversal of the Beaufort Sea Gyre and the overlying sea ice cover is an intriguing phenomenon that may reveal some insight into atmosphere‐cryosphere interactions through a detailed diagnostic analysis.

In this study we examine the atmospheric processes that may give rise to this reversal and maintain it through a case by case study of selected days during the late‐August‐early‐September reversal in 1980. We inspect the fields of total vertical motion and the contributions by advective, diabatic, and frictional mechanisms, as well as the isentropic potential vorticity, in order to identify the forcing functions.

This episode is an example of the classic cold low with a central cold pool, the surface and 500‐mbar fields aligned vertically, yet indications in the ageostrophic field of significant potential for baroclinic development, and a depression that remains anchored in the region for a significant period (27 days).

The episode occurs during a transition period from the summer regime with sluggish upper air anticyclonic circulation to the vigorous winter regime of a cyclonic vortex extending up through the stratosphere with concomitant increase of potential vorticity available for surface development. This transition, which appears to occur during a period that typically experiences rapid upper atmosphere cooling, may be the trigger for the creation of the low.

The surface heat flux appears to be a significant factor in the maintenance of the low although there are two factors at work. The first is the anomalous heat flow from the ocean along the ice‐ocean boundary and from open water in the diverging ice pack, but this primarily appears to result in a regional modulation of the synoptic‐scale effect. At the synoptic scale, there is significant heat flux associated with the very cold core of the depression and the associated pattern of the lower atmospheric heating moves with the wandering migration of the system within the region. In addition, there is an important dynamic contribution to development owing to the ageostrophic advection and convergence of cold air out of the core. The long duration of this feature within the Canada Basin must be traced to a complex interplay of heat flow processes related to the nature of the surface as well as the formation of the cold core of the depression, dynamic properties of mid‐tropospheric air flow, and the increase of upper air potential vorticity.
Deterministic signals in tree‐rings from North America
Authors: Currie Robert G.
Published: July 2010

Maximum entropy spectrum analysis of 305 tree‐ring chronologies from North America yields evidence for two terms with periods 18.6 ± 1.3 years (in 286 out of 305 series) and 10.5 ± 0.5 years in 244 instances. Statistical tests show the terms to be significant at confidence levels of 99.9 and 98 per cent, respectively. These signals are identified as the luni‐solar 18.6‐year Mnand the 10–11 year solar cycle Scterms. Amplitude and phase of the Mnsignal are non‐stationary with respect to both time and geography. In particular, abrupt 180° phase changes in wave polarity are often observed. During the seventeenth, and most of the eighteenth century, most of western North America experienced wet ‘W’ conditions at epochs of maximum in tidal forcing. At epochs 1787.2 and 1805.8 radical changes in phasing occurred, and from 1805.8 to present most of the region has been dry ‘D’ at epochs. A physical mechanism that can explain these phenomena is described briefly, and the implications for economic science briefly discussed.
Distribution of rainfall by synoptic type over natal, South Africa
Authors: Diab R. D. , Preston‐Whyte R. A. , Washington R.
Published: July 2010

Total rainfall over Natal, South Africa is the composite of rainfall from a number of synoptic rainfall‐producing systems. This paper identifies eight synoptic types and employs discriminant analysis in order to determine whether the defined synoptic types are statistically distinct. Eighty‐one per cent of the total rainfall is shown to be associated with four of the eight synoptic types. The dynamic characteristics of each synoptic type are examined and the seasonal and spatial rainfall patterns of the principal rainfall‐producing systems are described.
Temperature fluctuations in the mediterranean area during the last 120 years
Authors: Metaxas D. A. , Bartzokas A. , Vitsas A.
Published: July 2010

Based upon sea‐surface temperature (SST) data, recently corrected for bucket‐intake observational change, the SST fluctuations since 1873 in the Mediterranean are studied and compared with air temperature (AT) fluctuations at some land stations of this area and for the Northern Hemisphere (ATNH). Instead of the actual temperature, we used the frequency difference (per cent) of the number of the warm minus cold months, (fw—fc) annually and seasonally, smoothed using 10‐year moving averages. This frequency difference was found to be a linear function of the actual temperature.

For the whole Mediterranean, the trend of the SST is simple enough, with a minimum in about 1910 and a double maximum in about 1940 and 1965. A secondary minimum follows in 1975–1980, very strong in the eastern Mediterranean, with a rise after that to the present. This trend when compared with ATNH presents some differences: in the ATNH a minimum appears earlier, in 1890, but this is shown only slightly in the Mediterranean SST. The second SST maximum, in 1965, is not shown in ATNH, and the general rise of recent years starts in the ATNH about 10 years earlier.

When considering the AT of the Mediterranean stations, it can be seen that the rise, after the minimum of 1910, stops 15 years earlier than the SST and ATNH. Then, an anomalous and slow decrease follows until about 1975–1980, followed by a rise to the present, which is delayed in the eastern Mediterranean.
Kinematics of medial osteoarthritic knees before and after posterior cruciate ligament retaining total knee arthroplasty
Authors: Yue Bing , Varadarajan Kartik M. , Moynihan Angela L. , Liu Fang , Rubash Harry E. , Li Guoan
Published: July 2010

Total knee arthroplasty (TKA) is a widely accepted surgical procedure for the treatment of patients with end‐stage osteoarthritis (OA). However, the function of the knee is not always fully recovered after TKA. We used a dual fluoroscopic imaging system to evaluate the in vivo kinematics of the knee with medial compartment OA before and after a posterior cruciate ligament‐retaining TKA (PCR‐TKA) during weight‐bearing knee flexion, and compared the results to those of normal knees. The OA knees displayed similar internal/external tibial rotation to normal knees. However, the OA knees had less overall posterior femoral translation relative to the tibia between 0° and 105° flexion and more varus knee rotation between 0° and 45° flexion, than in the normal knees. Additionally, in the OA knees the femur was located more medially than in the normal knees, particularly between 30° and 60° flexion. After PCR‐TKA, the knee kinematics were not restored to normal. The overall internal tibial rotation and posterior femoral translation between 0° and 105° knee flexion were dramatically reduced. Additionally, PCR‐TKA introduced an abnormal anterior femoral translation during early knee flexion, and the femur was located lateral to the tibia throughout weight‐bearing flexion. The data help understand the biomechanical functions of the knee with medial compartment OA before and after contemporary PCR‐TKA. They may also be useful for improvement of future prostheses designs and surgical techniques in treatment of knees with end‐stage OA. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:40–46, 2011
Risk factors for recurrence following radical cystectomy for pathologic node negative bladder cancer
Authors: Hugen Cory M. , Polcari Anthony J. , FitzGerald Mary P. , Dauw Casey , Flanigan Robert C. , Quek Marcus L.
Published: July 2010

Background and Objectives

To evaluate for risk factors associated with bladder cancer recurrence in patients with pathologically negative lymph nodes.

Methods

A retrospective review of 405 patients undergoing radical cystectomy for bladder cancer between 1996 and 2008 was performed. Patients with node‐positive disease and <6 months of follow up were excluded. Clinical and pathological characteristics including stage, lymphadenectomy type (standard vs. extended), number of nodes removed, margin status, lymphovascular invasion (LVI), perineural invasion (PNI), presence of carcinoma in situ, and site of recurrence were evaluated. Kaplan–Meier analysis was used to calculate 5‐year recurrence‐free survival stratified by lymph node yield.

Results

Two hundred sixty patients met the inclusion criteria. Overall, 80 (30.8%) patients recurred within 5 years. Univariate analysis identified LVI, PNI, extravesical disease, positive margins, and lymph node yield <14 to be significant predictors of disease recurrence. On multivariate analysis LVI, PNI, and node yield <14 retained significance (P = 0.01, 0.037, 0.038, respectively). There was no difference in 5‐year recurrence free survival when stratified by node yield using the Kaplan–Meier method (P = 0.138).

Conclusions

We identified LVI, PNI, and lymph node yield <14 as three independent risk factors for bladder cancer recurrence in patients with node‐negative bladder cancer. J. Surg. Oncol. 2010;102:334–337. © 2010 Wiley‐Liss, Inc.
Analysis of E‐Selectin S128R gene polymorphism in pancreatic cancer
Authors: Panoussopoulos George S. , Theodoropoulos George , Michalopoulos Nikolaos V. , Gazouli Maria , Flessas John , Taka Stela , Stamopoulos Paraskevas , Manouras Andreas , Zografos George C.
Published: July 2010

Background

E‐selectin, an intercellular adhesion molecule that plays important roles in metastasis of tumor cells, has a polymorphism in exon 4 that results in the substitution of a serine by an arginine within the extracellular domain of the receptor, which increases its affinity for ligands. No evidence exist on the role of E‐selectin polymorphism in pancreatic cancer.

Methods

Eighty pancreatic cancer patients and 160 cases of normal healthy control subjects were investigated for genotype and allelic frequencies of S128R polymorphism of E‐selectin gene by PCR–RFLPs.

Results

The frequencies for “AA,” “CA,” and “CC” genotypes were 46.25%, 50%, and 3.75% in patients, and 63.75%, 26.9%, and 9.4% in healthy subjects, respectively. The “C” carriers group of patients (“CA + CC” genotype) and the “C” allele were over‐represented among the pancreatic cancer cases (P = 0.012 and 0.096, respectively). Advanced T stage, the presence of lymph node and other adverse pathologic characteristics were not significantly correlated with either the “CA + CC” genotype group of patients or the presence of “C” allele.

Conclusions

E‐selectin S128R “C” allele may confer an increased susceptibility to pancreatic cancer development, while its carriage status does not appear to be related to the aggressive features of this malignancy. J. Surg. Oncol. 2010;102:604–607. © 2010 Wiley‐Liss, Inc.
Preoperative chest computerized tomography in patients with locally advanced mid or lower rectal cancer: Its role in staging and impact on treatment strategy
Authors: Choi Dong Jin , Kwak Jung Myun , Kim Jin , Woo Si Uk , Kim Seon Hahn
Published: July 2010

Objectives

Pulmonary metastasis is frequent in rectal cancer. Some guidelines recommend chest computerized tomography (CT) for preoperative workup in rectal cancer patients, which have no solid evidence to support this recommendation. This study was designed to evaluate the role of chest CT on preoperative staging in rectal cancer patients and to assess the impact on treatment strategy.

Methods

Data were prospectively collected from 103 clinically T3/T4 mid or lower rectal cancer patients who had chest X‐ray (CXR) and CT to evaluate lung metastasis. The chest images were classified into four groups: metastasis, indeterminate, benign, and negative. Patients showing indeterminate lesions had follow‐up CTs at 3‐ to 6‐month intervals.

Results

Nine patients (8.7%) had pulmonary metastases detected on CT. CXR did not reveal any pulmonary metastatic lesions in four of the nine patients. Of these four, treatment was changed in three patients because of these findings. Forty (38.8%) patients had indeterminate nodules on chest CT. Of these, 37 patients had follow‐up CTs and four patients (10.8%) showed interval changes that were confirmed as pulmonary metastasis.

Conclusions

It seems reasonable to perform chest CT for preoperative staging in patients with T3/T4 mid or lower rectal cancer. J. Surg. Oncol. 2010;102:588–592. © 2010 Wiley‐Liss, Inc.
Validation and evaluation of an HPLC methodology for the quantification of the potent antimitotic compound (+)‐discodermolide in the Caribbean marine sponge Discodermia dissoluta
Authors: Valderrama Katherine , Castellanos Leonardo , Zea Sven
Published: July 2010

The sponge Discodermia dissoluta is the source of the potent antimitotic compound (+)‐discodermolide. The relatively abundant and shallow populations of this sponge in Santa Marta, Colombia, allow for studies to evaluate the natural and biotechnological supply options of (+)‐discodermolide. In this work, an RP‐HPLC‐UV methodology for the quantification of (+)‐discodermolide from sponge samples was tested and validated. Our protocol for extracting this compound from the sponge included lyophilization, exhaustive methanol extraction, partitioning using water and dichloromethane, purification of the organic fraction in RP‐18 cartridges and then finally retrieving the (+)‐discodermolide in the methanol–water (80:20 v/v) fraction. This fraction was injected into an HPLC system with an Xterra RP‐18 column and a detection wavelength of 235 nm. The calibration curve was linear, making it possible to calculate the LODs and quantification in these experiments. The intra‐day and inter‐day precision showed relative standard deviations lower than 5%. The accuracy, determined as the percentage recovery, was 99.4%. Nine samples of the sponge from the Bahamas, Bonaire, Curaçao and Santa Marta had concentrations of (+)‐discodermolide ranging from 5.3 to 29.3 μg/g−1 of wet sponge. This methodology is quick and simple, allowing for the quantification in sponges from natural environments, in situ cultures or dissociated cells.
MEKC determination of IgG in human serum via a pH‐mediated acid stacking method
Authors: Wu Yi‐Wei , Liu Jun‐Feng , Deng Zhen‐Li , Zhang Jing , Jiang Feng , Xiong Kun , Zhang Haili
Published: July 2010

An on‐column preconcentration technique, pH‐mediated acid stacking, was used in this study to improve the sensitivity of MEKC‐UV analysis of IgG in human serum. Various parameters affecting pH‐mediated acid stacking were optimized systematically. To eliminate the matrix interferences of human serum and to combine the sample pretreatment procedure with the detection methodology, silica‐coated Fe3O4 magnetic nanoparticles modified with N‐(2‐aminoethyl)‐3‐aminopropyl‐trimethoxysilane were prepared and employed as solid phase extraction adsorbent to remove the abundant HSA from human serum. HSA was quantitatively removed by silica‐coated Fe3O4 magnetic nanoparticles modified with N‐(2‐aminoethyl)‐3‐aminopropyl‐trimethoxysilanes without retaining IgG at pH 9.3. Under the optimum conditions, the sensitivity of IgG was improved 40.3‐fold using a 100 s electrokinetic injection as compared with a 6 s hydrodynamic injection. The detection limit of IgG was found to be 0.1 mg/L, and the proposed method was successfully applied for the determination of IgG in human serum with satisfactory results.
RP‐HPLC method with fluorescence detection for amino acids D/L ratio determination in fossil bones as a marker of DNA preservation
Authors: Iuliani Piera , Di Federico Lucia , Fontecchio Gabriella , Carlucci Giuseppe
Published: July 2010

Only a small proportion of old specimens contain DNA that can be amplified by PCR. Therefore, rapid screening methods are crucial to identify the large fraction of samples that are so badly preserved that there is no need to attempt DNA extraction. In particular, the extent of racemization of some amino acids has proved to be a very useful proxy for DNA preservation. In this study, a rigorous method for the determination of the D/L ratio for aspartic acid and alanine by RP‐HPLC with fluorescence detection was developed with the aim to obtain a fast and cheap procedure for both sample preparation and amino acids analysis, without compromising precision and accuracy.
Determination of fluoride as fluorosilane derivative using reversed‐phase HPLC with UV detection for determination of total organic fluorine
Authors: Musijowski Jacek , Szostek Bogdan , Koc Mariusz , Trojanowicz Marek
Published: July 2010

A quantitative method for fluoride determination using RP HPLC and UV detection was developed. The method is based on the reaction of fluoride with triphenylhydroxysilane in highly acidic conditions and extraction of the reaction product into n‐heptane. Chromatographic conditions as well as the derivatization parameters were optimized. LOQ for fluoride ion was evaluated as 0.25 μM (4.75 ppb) and linear range of response up to 75 μM (1.42 ppm) was obtained. The method was developed as a part of a procedure designed for the determination of total organic fluorine in natural waters, using SPE on a carbon sorbent and sodium biphenyl reagent for the defluorination reaction. LOD for a model compound, perfluorooctanoic acid, calculated for the complete procedure with 2000‐fold preconcentration, is 20 ppt (n=4). Initial results show feasibility of total organic fluorine determination for environmental purposes.
The clinical significance of nasal irrigation bottle contamination
Authors: Keen Mark , Foreman Andrew , Wormald Peter‐John
Published: July 2010

Objectives/Hypothesis:

This study aimed to assess the clinical relevance of contamination of nasal irrigation bottles in patients with recalcitrant chronic rhinosinusitis (CRS). Secondary investigations to identify the presence of bacterial biofilms on the inner surface of the bottles and to assess different sterilization methods were also undertaken.

Study Design:

Prospective, observational.

Methods:

Eleven patients with recalcitrant CRS who were already using nasal irrigation as part of their treatment regimen were examined every 2 weeks for a period of 6 weeks. At each visit, a culture sample was taken from their irrigation bottle and middle meatus, and they were given a new irrigation bottle. Irrigation bottles from six patients were analyzed with scanning electron microscopy (SEM) to detect biofilm formation. Finally, new bottles were inoculated with different strains of Staphylococcus aureus and then cleaned with different methods. The bottles were cultured immediately after cleaning and 48 hours later.

Results:

Overall, 42 of 43 (97%) bottles collected demonstrated bacterial growth. Concurrent sinonasal and bottle infection with S. aureus was seen in 51% of patients during the study. Bacterial biofilms were demonstrated on the inner surface of four of the six irrigation bottles tested. Treatment with Milton's solution (1% NaOCl plus 19% NaCl) and microwaving were found to be effective methods for sterilizing the bottles both initially after the cleaning and 48 hours later.

Conclusions:

Patients who irrigate their nose and sinuses commonly contaminate their irrigation bottle, most often with S. aureus, which can be in the biofilm form. Simple cleaning methods could reduce contamination of the bottles. Laryngoscope, 2010
Head and neck cancer stem cells: The side population
Authors: Tabor Mark H. , Clay Matthew R. , Owen John H. , Bradford Carol R. , Carey Thomas E. , Wolf Gregory T. , Prince Mark E.
Published: July 2010

Objectives/Hypothesis:

The cancer stem cell (CSC) theory concludes that a subpopulation of cancer cells, the cancer stem cells, can self‐renew and are responsible for tumor growth. Previous studies have identified cells able to efflux Hoechst 33342 dye as the side population (SP). SP cells and CSCs share many characteristics, suggesting the SP isolated from malignant tumors contains CSCs.

Study Design:

Experimental Study.

Methods:

The SP was isolated from a head and neck cancer cell line and analyzed for CSC‐like characteristics.

Results:

The SP demonstrated the ability to reproduce both SP and non‐side population (NSP) cells from as few as one cell. The SP had lower expression of active β‐catenin and more resistance to 5‐fluorouracil; the SP also demonstrated greater expression of Bmi‐1 (4.3‐fold) and ABCG2 (1.4‐fold). SP cells were able to produce tumors in an animal model, whereas NSP were not. SPs were identified in two primary human tumors.

Conclusions:

This work adds to the evidence that the SP in head and neck cancer represents cells with CSC properties and provides a method by which CSCs can be isolated and studied. Laryngoscope, 2011
Symptomatic maxillary sinus retention cysts: Should they be removed?
Authors: Albu Silviu
Published: July 2010

Objectives/Hypothesis:

Recently, endoscopic sinus surgery (ESS) endoscopic sinus surgery (ESS) okay? has become the surgical procedure of choice for removing retention cysts from the maxillary sinus. The aim of our study was to determine the relationship between symptomatic relief and ESS with or without endoscopic excision of maxillary cysts.

Study Design:

Prospective, randomized study.

Methods:

Inclusion criteria were symptomatic maxillary cysts filling at least 50% of the sinus space. We conducted a prospective, randomized study comprising 80 patients. Of the patients, 41 underwent endoscopic ethmoidectomy, middle meatus antrostomy, and excision of the cysts (group A); and 39 underwent ethmoidectomy and antrostomy without cyst detachment (group B). During follow‐up an attempt was made to correlate symptomatic failure with type of surgery, computed tomography (CT) score, cyst size, and ratio of cyst size/antral size.

Results:

Symptomatic failure occurred in nine cases: four in the group A and five in group B. There was no relationship between success rates and type of surgery, CT score, cyst size, and ratio of cyst size/antral size.

Conclusions:

Endoscopic ethmoidectomy and middle meatus antrostomy without cyst detachment yielded similar outcomes with cyst extirpation through the antrostomy. Our treatment should be aimed in restoring ventilation and drainage of the dependent maxillary sinus. Laryngoscope, 2010