bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical studies on the parameters influencing steel ladle heat loss rate, thermal stratification during holding and steel stream temperature during teeming
Authors: Pan Yuhua , Grip Carl‐Erik , Björkman Bo
Published: December 2004

Numerical experiments were performed on fluid flow and heat transfer in 107‐tonne steel ladles by 3‐step implementations of numerical models. In the first step, a 1‐dimensional numerical model was used to predict heat conduction fluxes through the ladle wall, bottom and top slag layer. In the second step, by means of computational fluid dynamics (CFD) modelling and employing the predicted heat loss fluxes as thermal boundary conditions, a 2‐dimensional CFD model was applied to simulate natural convection in steel ladles during the holding period before teeming. In the third step, a 3‐dimensional CFD model was implemented to further simulate fluid dynamics in the same ladles with drainage flows during teeming. Using these mathematical numerical models, the bulk cooling rate of the steel melt, the extent of thermal stratification during holding and the steel stream temperature during teeming were investigated for 2 types of 107‐tonne steel ladles lined, respectively, with alumina and spinel in walls. In these investigations, the following 4 parameters were considered: (i) ladle lining inside surface (hot‐face) temperature before tapping, (ii) top slag layer thickness, (iii) holding time and (iv) teeming rate. An important result of these investigations is that the concerned parameters all significantly influence the steel stream temperature during teeming, and the differences in teeming stream temperatures among different ladles, caused by these parameters, can be up to 20°C, which may be essential to temperature control in tundishes during continuous casting.
Comparison of Kistler 9861A force platform and Chattecx Balance System® for measurement of postural sway: correlation and test–retest reliability
Authors: Rogind H. , Simonsen H. , Era P. , Bliddal H.
Published: December 2004

Measurement of postural sway has several potential applications in sports medicine. Traditionally, however, rather complicated equipment has been applied. The purpose of the study was to compare two devices based on two different methods of measuring postural sway: (i) a sophisticated Kistler 9861A force platform (KIS)—which all but requires a laboratory setting—and (ii) Chattecx Balance System® (CBS)—which is particularly suited for measurement of sway in the dynamic environment of sports. Measurement of sway was performed in 29 subjects twice at baseline and twice at follow‐up 2–4 weeks later. One measurement consisted of four 25‐second sequences (eyes open, parallel feet; eyes closed, parallel feet; eyes open, tandem Romberg; eyes closed, tandem Romberg). Factor analysis revealed influence of sight and stance on sway, marked interaction between these two factors and a decrease in sway on retest on the same day. Coefficients of variation were—KIS: 0.13–0.23; CBS: 0.11–0.25. Body height was a covariate for all parameters. Kistler 9861A force platform and CBS were correlated (baseline: rs = 0.47; follow‐up: rs = 0.9). These findings suggest that, when the effects of acclimatization and covariance of body height were taken into account, CBS was as reliable and reproducible as KIS in our laboratory.
Recent advances in the understanding of the repeated bout effect: the protective effect against muscle damage from a single bout of eccentric exercise
Authors: McHugh Malachy P.
Published: December 2004

The repeated bout effect refers to the adaptation whereby a single bout of eccentric exercise protects against muscle damage from subsequent eccentric bouts. While the mechanism for this adaptation is poorly understood there have been significant recent advances in the understanding of this phenomenon. The purpose of this review is to provide an update on previously proposed theories and address new theories that have been advanced. The potential adaptations have been categorized as neural, mechanical and cellular. There is some evidence to suggest that the repeated bout effect is associated with a shift toward greater recruitment of slow twitch motor units. However, the repeated bout effect has been demonstrated with electrically stimulated contractions, indicating that a peripheral, non‐neural adaptation predominates. With respect to mechanical adaptations there is evidence that both dynamic and passive muscle stiffness increase with eccentric training but there are no studies on passive or dynamic stiffness adaptations to a single eccentric bout. The role of the cytoskeleton in regulating dynamic stiffness is a possible area for future research. With respect to cellular adaptations there is evidence of longitudinal addition of sarcomeres and adaptations in the inflammatory response following an initial bout of eccentric exercise. Addition of sarcomeres is thought to reduce sarcomere strain during eccentric contractions thereby avoiding sarcomere disruption. Inflammatory adaptations are thought to limit the proliferation of damage that typically occurs in the days following eccentric exercise. In conclusion, there have been significant advances in the understanding of the repeated bout effect, however, a unified theory explaining the mechanism or mechanisms for this protective adaptation remains elusive.
Predictors of 6‐minute walk test results in lean, obese and morbidly obese women
Authors: Hulens M. , Vansant G. , Claessens A. L. , Lysens R. , Muls E.
Published: December 2004

The aim of this study was first, to assess the presence of medical conditions that might interfere with walking; second, to assess the differences in walking capacity, perceived exertion and physical complaints between lean, obese and morbidly obese women; and third, to identify anthropometric, physical fitness and physical activity variables that contribute to the variability in the distance achieved during a 6‐minute walk test in lean and obese women.

A total of 85 overweight and obese females (18–65 years, body mass index (BMI) ≥ 27.5 kg m−2), 133 morbidly obese females (BMI ≥ 35 kg m−2) and 82 age‐matched sedentary lean female volunteers (BMI ≤ 26 kg m−2) were recruited. Patients suffering from severe musculoskeletal and cardiopulmonary disease were excluded from the study. Prior to the test, conditions that might interfere with walking and hours of TV watching were asked for. Physical activity pattern was assessed using the Baecke questionnaire. Weight, height, body composition (bioelectrical impedance method), isokinetic concentric quadriceps strength (Cybex) and peak oxygen uptake (peakVO2—bicycle ergometer) were measured. A 6‐minute walk test was performed and heart rate, walking distance, Borg rating scale of perceived exertion (RPE) and physical complaints at the end of the test were recorded.

In obese and particularly in morbidly obese women suffering from skin friction, urinary stress incontinence, varicose veins, foot static problems and pain, wearing insoles, suffering from knee pain, low back pain or hip arthritis were significantly more prevalent than in lean women (P < 0.05). Morbidly obese women (BMI > 35 kg m−2N = 133) walked significantly slower (5.4 km h−1) than obese (5.9 km h−1) and lean women (7.2 km h−1, P < 0.05), were more exerted (RPE 13.3, 12.8 and 12.4, respectively, P < 0.05) and complained more frequently of dyspnea (9.1%, 4.7% and 0% resp., P < 0.05) and musculoskeletal pain (34.9%, 17.7% and 11.4% resp., P < 0.05) at the end of the walk. In a multiple regression analysis, 75% of the variance in walking distance could be explained by BMI, peakVO2, quadriceps muscle strength age, and hours TV watching or sports participation.

These data suggest that in contrast with lean women, walking ability of obese women is hampered not only by overweight, reduced aerobic capacity and a sedentary life style, but also by perceived discomfort and pain. Advice or programs aimed at increasing walking for exercise also need to address the conditions that interfere with walking, as well as perceived symptoms and walking difficulties in order to improve participation and compliance.
Identification of ribosomal proteins S2 and L10a as tumor antigens recognized by HLA‐A26‐restricted CTL
Authors: Koga M. , Shichijo S. , Yamada A. , Ashihara J. , Sawamizu H. , Kusukawa J. , Itoh K.
Published: December 2004

Abstract: Recent identification of cytotoxic T lymphocyte (CTL)‐directed peptides binding to the HLA‐A2 and ‐A24 alleles has opened the door to peptide‐based cancer immunotherapies. However, subsequent studies have succeeded in identifying no more than a few CTL‐directed peptides that bind to alleles other than HLA‐A2 and ‐A24, thus hampering development of immunotherapies directed at other alleles. We have shown in this study that two genes coding for ribosomal proteins (S2 and L10a) encoded tumor antigens recognized by HLA‐A26‐restricted CTLs. The S2 mRNA was expressed in all of the cancer cells and non‐malignant cell lines tested, but was not expressed in normal tissues except for the testis, muscle, and peripheral mononuclear leukocyte cell (PBMC). In contrast, the L10a mRNA was expressed in all of these cancer and non‐malignant cell lines, and also normal tissues, although the expression levels in normal tissues were mostly low. One S2‐derived peptide and two L10a‐derived peptides had the ability to induce HLA‐A26‐restricted and peptide‐specific CTLs reactive to tumor cells in PBMCs of cancer patients, respectively. These ribosomal protein‐derived peptides, and particularly the S2‐derived peptide, could be suitable for use in peptide‐based immunotherapy for HLA‐A26+ cancer patients.
Identification of a novel DPB1 allele, DPB1*9301, by sequence‐based typing in a Lahu ethnic minority of China
Authors: Liu Z.‐H. , Fan X. , Lin J. , Fu Y. , Liu X. , Xu A.
Published: December 2004

Abstract: A novel DPB1 allele (DPB1*9301) has been identified in an individual from the Lahu ethnic minority of China. Its sequence was confirmed by sequencing the PCR products and clones. This allele differs from DPB1*0601, *1701 and *3701 by two nucleotides in each, and results in amino acids substitution.
Estimating Percentiles of Uncertain Computer Code Outputs
Authors: Oakley Jeremy
Published: December 2004

A deterministic computer model is to be used in a situation where there is uncertainty about the values of some or all of the input parameters. This uncertainty induces uncertainty in the output of the model. We consider the problem of estimating a specific percentile of the distribution of this uncertain output. We also suppose that the computer code is computationally expensive, so we can run the model only at a small number of distinct inputs. This means that we must consider our uncertainty about the computer code itself at all untested inputs. We model the output, as a function of its inputs, as a Gaussian process, and after a few initial runs of the code use a simulation approach to choose further suitable design points and to make inferences about the percentile of interest itself. An example is given involving a model that is used in sewer design.
Statistical Image Analysis for a Confocal Microscopy Two-Dimensional Section of Cartilage Growth
Authors: Al-Awadhi Fahimah , Jennison Christopher , Hurn Merrilee
Published: December 2004

Images are the source of information in many areas of scientific enquiry. A common objective in these applications is the reconstruction of the true scene from a degraded image. When objects in the image can be described parametrically, reconstruction can proceed by fitting a high level image model. We consider the analysis of confocal fluorescence microscope images of cells in an area of cartilage growth. Biological questions that are posed by the experimenters concern the nature of the cells in the image and changes in their properties with time. Our model of the imaging process is based on a detailed analysis of the data. We treat the true scene as a realization of a marked point process, incorporating this as the high level prior model in a Bayesian analysis. Inference is by simulation using reversible jump versions of Markov chain Monte Carlo algorithms which can handle the varying dimension of the image description arising from an unknown number of cells, each with its own parameters.
Higher Hb level is associated with better early functional recovery after hip fracture repair
Authors: Lawrence Valerie A. , Silverstein Jeffrey H. , Cornell John E. , Pederson Thomas , Noveck Helaine , Carson Jeffrey L.
Published: December 2004

BACKGROUND: The benefits and indications for blood transfusion are controversial. One possible reason to transfuse is to improve functional recovery after major surgery. However, the data linking improved function with higher Hb concentration are limited.

STUDY DESIGN AND METHODS: A retrospective cohort study was performed in 5793 patients at least 60 years old undergoing hip fracture repair at 20 academic and community hospitals. The primary outcome was distance walked at the time of discharge from the hospital. The mean postoperative Hb concentration was the main exposure variable and was defined as the average value from Day 1 after surgery to discharge. We used robust regression to assess the association between postoperative Hb level with distance walked, controlling for other preoperative variables that could influence functional recovery.

RESULTS: On bivariate analysis, the predicted distance walked at discharge in feet (95% CI) increased with higher Hb levels (7 g/dL, 56 feet [42‐70]; 8 g/dL, 61 feet [54‐68]; 9 g/dL, 67 feet [64‐70]; 10 g/dL, 74 feet [72‐77]; 11 g/dL, 83 feet [80‐85]; 12 g/dL, 92 feet [87‐96]). After adjustment for other factors associated with ability to walk, higher average postoperative Hb level was independently associated with walking greater distance (p < 0.001).

CONCLUSIONS: Higher postoperative Hb level may improve functional recovery after hip fracture repair. If confirmed with clinical trials, this finding would provide a rationale to maintain higher Hb concentrations in elderly patients recovering from surgery.
Mutations in GYPB exon 5 drive the S–s–U+var phenotype in persons of African descent: implications for transfusion
Authors: Storry Jill R. , Reid Marion E. , Fetics Susan , Huang Cheng‐Han
Published: December 2004

BACKGROUND: The S–s–U– phenotype in African Americans is due to a GYPB deletion, however the molecular basis for the S–s–U+var phenotype is poorly understood. Variable reactivity of S–s–U+var RBCs with monoclonal anti‐He or by anti‐U has been demonstrated, however the underlying molecular bases for this phenotype remain to be established.

STUDY DESIGN AND METHODS: Hemagglutination was performed on 104 S–s– blood samples using monoclonal anti‐He and anti‐U. GYPB was sequenced from selected samples. Allele and exon‐specific PCR analysis was used to identify wild‐type and mutant alleles.

RESULTS: The RBCs of 49‐percent S–s– samples were identified as S–s–U+var by hemagglutination. Sequencing analysis of 41 samples revealed 1) a point mutation at +5 (g > t) of intron 5 that resulted in skipping of exon 5 in 34 samples; 2) two mutations (208G > T and 230C > T) caused partial skipping of exon 5 in four samples due to activation of a cryptic 3′ splice site that resulted from a C > G transversion at nt251 present in all GYPB*S alleles and most GYPB*s alleles tested. Three samples were heterozygous for the mutated alleles.

DISCUSSION: T he S–s–U+var phenotype arises from changes in or around GYPB exon 5. The weak expression of U and in most examples, He, may be due to low levels of normal transcription of the variant gene or to posttranscriptional down regulation.
Autoantibody formation after alloimmunization: are blood tranfusions a risk factor for autoimmune hemolytic anemia?
Authors: Young Pampee P. , Uzieblo Alison , Trulock Elbert , Lublin Doug M. , Goodnough Lawrence T.
Published: December 2004

BACKGROUND:  The development of RBC autoanti‐bodies resulting from or associated with allogeneic blood transfusions (i.e., RBC autoimmunization) is not a well‐recognized complication of RBC transfusions.

STUDY DESIGN AND METHODS:  T he presentation, laboratory evaluation, clinical course, and management of two patients whose autoimmune hemolytic anemia followed allogeneic blood transfusion and occurred in association with the development of one or more alloantibodies is described. A retrospective analysis was performed of our blood‐bank records over 1 year to determine the frequency of RBC autoimmunization associated with alloimmunization.

RESULTS:  Out of 2618 patients who had a positive DAT or IAT, 121 were identified with RBC autoantibodies; 41 of these patients had both allo‐ and autoantibodies to RBC antigens, whereas the remainder, 80, had only autoantibodies. At least 34 percent (12/41) of these patients (none with hemoglobinopathy) developed their autoantibodies in temporal association with alloimmuni‐zation after recent blood transfusion(s).

CONCLUSION:  RBC autoimmunization and the development of autoimmune hemolytic anemia should be recognized as a complication of allogeneic blood transfusion. The need for additional blood transfusion was successfully avoided in one patient by treatment with recombinant human EPO and corticosteroid therapy. Once RBC autoimmunization is identified, subsequent management should incorporate a strategy that minimizes subsequent exposure to allogeneic blood.
Universal leukoreduction decreases the incidence of febrile nonhemolytic transfusion reactions to RBCs
Authors: King Karen E. , Shirey R. Sue , Thoman Sandra K. , Bensen‐Kennedy Debra , Tanz Warren S. , Ness Paul M.
Published: December 2004

BACKGROUND:  Febrile nonhemolytic transfusion reactions (FNHTR) is a relatively common complication associated with allogeneic transfusion. Because WBCs have been implicated in the mechanism of FNHTRs, it has been proposed that the transfusion of leukoreduced RBCs should be associated with a decreased incidence of FNHTRs. These reactions are generally not life threatening, but they are expensive in their management, evaluation, and associated blood‐product wastage. Over the past several years, the proportion of leukoreduced RBCs has increased at Johns Hopkins Hospital in an effort to move toward complete leuko‐reduction. A retrospective analysis is reported here of FNHTRs in RBC recipients as the inventory increased in percentage of leukoreduced RBC units.

STUDY DESIGN AND METHODS:  Between July 1994 and December 2001, all transfusion reactions (TRs) associated with the transfusion of allogeneic RBCs were retrospectively analyzed. Both computerized data and individual TR reports were reviewed. Patients who had both allergic and febrile features were included as part of both categories. TRs were reported as a percentage of total units transfused. Two time periods were selected for direct comparison. July to December 1994 represents the time period before the initiation of an increase in leuko‐reduction. July to December 2001 represents a time period when almost complete leukoreduction (99.5%) had been achieved. The TR data were compared between these two time periods, comparing a time before leuko‐reduction to a time period after leukoreduction had been achieved. The trends in TRs over the entire 7.5‐year period of July 1994 to December 2001 were also assessed.

RESULTS:  In the initial period before the initiative to move toward leukoreduction, 96 percent of our RBC inventory was non‐leukoreduced. In the study period after leukoreduction, 99.5 percent of our RBC inventory was leukoreduced. When comparing these two time periods, the incidence of FNHTRs decreased from 0.37 percent to 0.19 percent (p = 0.0008). The trend over the entire 7.5‐year study period confirms the decrease in FNHTRs as the percentage of leukoreduced RBCs increased. The incidence of allergic TRs has remained unchanged over this time period.

CONCLUSIONS:  As our institution has increased its inventory of leukoreduced RBCs to approximately 100 percent, selective leukoreduced protocols have been discontinued. The incidence of FNHTRs has decreased significantly and the rate of allergic reactions has essentially remained unchanged. Leukoreduction is effective in decreasing FNHTRs associated with the transfusion of allogeneic RBCs.
A Correlation Between Migraine, Histamine and Immunoglobulin E
Authors: Gazerani P. , Pourpak Z. , Ahmadiani A. , Hemmati A. , Kazemnejad A.
Published: December 2004

Although migraine affects about 15% of population and many studies have been performed to find the mechanism and a successful management, the physiopathology of migraine is still largely unknown. The possibility of an immunoglobulin E (IgE)‐mediated allergic mechanism and the role of histamine remain controversial.

The aim of the present study was to evaluate serum total IgE and histamine levels in migraine patients and the influence of allergy on them.

Seventy patients (18–58 years) with migraine without aura were divided into two groups according to their history of allergy (60% with and 40% without allergy). Serum samples were collected during fasting without allowing any premedication during the two periods of attack and remission. There was a control group containing 45 healthy volunteers. Serum total IgE and histamine levels were measured by enzyme‐linked immunosorbent assay and fluorimetric methods, respectively.

Mean and standard errors of serum histamine (ng/ml) and total IgE (IU/ml) levels were found in the control group to be 48.16 ± 2.70 and 38.31 ± 3.20, in the migraine with allergy group 159.11 ± 4.60 and 303.30 ± 42.50 and in the migraine without allergy group 105.01 ± 8.50 and 79.07 ± 2.70, respectively.

Total IgE levels in migraine with allergy group were found to be significantly (P < 0.0001) above that in the control and another group, suggesting an influence of an IgE‐mediated mechanism on migraine. Although the plasma histamine levels, which were significantly elevated (P < 0.0001) in patients with migraine, both during headache and symptom‐free periods, when compared with the control group, indicate that there is an increased susceptibility to histamine in allergic conditions, this molecule has also an unrelated role in migraine.

The relationship between allergy and migraine can be based, in part, on an IgE‐mediated mechanism, and histamine release plays an important role.

Thus, the avoidance of allergic conditions in migraine patients may be a simple, helpful way for prophylaxis or their treatment.
Infection of Human Mononuclear Phagocytes and Macrophage‐Like THP1 Cells with Leishmania donovani Results in Modulation of Expression of a Subset of Chemokines and a Chemokine Receptor
Authors: Dasgupta B. , Roychoudhury K. , Ganguly S. , Akbar M. A. , Das P. , Roy S.
Published: December 2004

The expression of chemokines and chemokine receptors was studied in Leishmania donovani (LD)‐infected human mononuclear phagocytes and the human monocytic cell line THP1. Our studies showed that LD infection caused the upregulation of three β chemokines (macrophage inflammatory protein‐1 alpha (MIP‐1α), MIP‐1β and RANTES (regulated on activation normal T cell expressed and secreted)), one α chemokine (interleukin‐8 (IL‐8)) and the CC chemokine receptor 5 (CCR5) but not CCR1, as evident from reverse transcriptase‐polymerase chain reaction (RT‐PCR) analysis. The CCR5 upregulation in human mononuclear phagocytes and THP1 cells was also evident by confocal microscopy. The possible association of such upregulation in relation to Leishmania and human immunodeficiency virus (HIV) coinfection was discussed.
A Novel Function for Chemokines: Downregulation of Neutrophil Migration
Authors: Lang K. , Hatt H. , Niggemann B. , Zaenker K. S. , Entschladen F.
Published: December 2004

Migration is a key function of stem cells during ontogenesis, of fibroblasts in wound healing and of immune cells in host defence. The signals that initiate migration are as important as signals that terminate migration, once the destination has been reached. We now show that formyl‐methionyl‐leucyl‐phenylalanine (fMLP)‐induced migration of neutrophils was inhibited by increasing concentrations of interleukin‐8 (IL‐8). IL‐8 dose dependently increased the frequency and the duration of stop‐periods, whereas the percentage of cells of a population that was locomotory active remained constant. The stop‐signal delivered by IL‐8 was intracellularly transduced by a dichotomic pathway: (i) the activation of the adenylyl cyclase leads to an increase of cytosolic cyclic adenosine monophosphate, which results in an activation of the sarcoplasmatic/endoplasmatic reticulum calcium ATPase pump and a calcium sequestration; (ii) the activation of the phospholipase Cβ (PLCβ) generates inositol‐1,4,5‐phosphate (IP3) and diacylglycerol (DAG), which results in IP3‐mediated release of intracellularly stored calcium in the endoplasmatic reticulum and DAG‐mediated activation of protein kinase C. Thus, we show for the first time that a chemokine, IL‐8, in concert with fMLP, downregulates the neutrophil migration through the regulation of the intracellular calcium concentration via the adenylyl cyclase and the PLCβ2.
Susceptibility of Mice Deficient in the MHC Class II Transactivator to Infection with Mycobacterium tuberculosis
Authors: Repique C. J. , Li A. , Brickey W. J. , Ting J. P. Y. , Collins F. M. , Morris S. L.
Published: December 2004

Major histocompatibility complex (MHC) class II antigen presentation and subsequent CD4+ T‐cell activation are critical for acquired immunity to Mycobacterium tuberculosis infection. MHC class II gene expression is primarily controlled by the master transactivator CIITA protein. Without functional CIITA protein, MHC class II expression is lost, impairing immune responses and increasing susceptibility to infection. In this study, we compared protective immune responses of CIITA‐deficient mice and wild‐type C57BL/6 controls with low dose aerosol M. tuberculosis infection. After aerogenic challenge, CIITA–/– mice failed to limit mycobacterial growth (2.5 and 2.0 log10 > WT lung and spleen CFUs, respectively, at day 58). Lung histopathology involved extensive necrosis, severe pneumonitis and overwhelming inflammation in the gene knockout mice. Mean survival time for CIITA–/– mice was significantly reduced (57 versus >300 days for WT). This extreme sensitivity to tuberculous infection was largely attributed to the absence of CD4+ cells. Flow cytometric studies detected virtually no CD4+ cells in CIITA–/– mouse spleens after infection versus elevated numbers in WT spleens. Failed CD4+ T‐cell expansion markedly reduced interferon‐γ (IFN‐γ production in CIITA–/– mice versus WT controls. These results suggest the necessity of a functional CIITA pathway for controlling tuberculous infections and that interventions targeting CIITA expression may be useful antimycobacterial therapeutics.
Suppression of Interleukin‐12 Production through Endogenously Secreted Interleukin‐10 in Activated Dendritic Cells: Involvement of Activation of Extracellular Signal‐Regulated Protein Kinase
Authors: Xia C.‐Q. , Kao K. J.
Published: December 2004

Our recent study suggested the reverse relationship between the production of interleukin‐10 (IL‐10) and IL‐12 in dendritic cells (DCs) activated by lipopolysaccharide (LPS) or LPS plus interferon (IFN)‐γ. In the present study, a series of experiments were performed to investigate the mechanisms responsible for this reverse relationship. Our results showed that neutralization of the secreted IL‐10 by antibody could enhance the production of IL‐12. Neutralization of IL‐12 by antibody did not affect the IL‐10 production. Addition of exogenous IL‐10 suppressed the production of IL‐12 by activated DCs, and addition of exogenous IL‐12 did not affect IL‐10 production. TaqMan real‐time reverse transcriptase‐polymerase chain reaction supported the fact that the observed effects occurred at mRNA transcription level. We also found that LPS or LPS plus IFN‐γ significantly enhanced the phosphorylation of extracellular signal‐regulated protein kinase (ERK) and p38 mitogen‐activated protein kinase. In addition, inhibition of ERK by PD98059 significantly suppressed IL‐10 and increased the IL‐12 production. Exogenous IL‐10 reversed the upregulated production of IL‐12 induced by PD98059. The above findings suggest a unidirectional negative autocrine regulation of IL‐12 by IL‐10 in activated DCs and that activation of ERK involves the differential production of IL‐10 and IL‐12 by activated DCs. Thus, the regulation of differential production of IL‐10 and IL‐12 may play an important role for DCs in priming T helper 1 (Th1) or Th2 in the immune responses.
Temperature Alters Lipopolysaccharide‐Induced Cytokine Secretion by RAW 264.7 Cells
Authors: Kirkley J. E. , Thompson B. J. , Coon J. S.
Published: December 2004

Local and systemic temperature change is associated with the immune response to infection, but the role of temperature remains poorly understood. To study the effect of temperature on macrophage activation by lipopolysaccharide (LPS), RAW 264.7 cells were incubated with LPS at different temperatures and secretion of three cytokines was measured. Incubation at 31 °C increased tumour necrosis factor (TNF) secretion when compared with 37 °C, while cells exposed at 39 °C secreted less TNF. Interleukin‐6 (IL‐6) secretion was less at 31 °C than at 37 °C and remained unchanged at 39 °C. Interleukin‐10 secretion was depressed on either side of 37 °C. Only IL‐6 secretion was sensitive to preincubation temperature effects. The kinetics of cytokine secretion and steady‐state mRNA analysis indicated potentially different mechanisms of temperature regulation for TNF and IL‐6.
Retroviral Transfer of T‐Cell Receptor Genes Produces Cells with a Broad Range of Lytic Activity
Authors: Orentas R. J. , Bircher L. A. , Roskopf S.
Published: December 2004

The ability to transfer the T‐cell receptor (TCR) for antigen using a retroviral vector has opened the door to a new paradigm for T‐cell‐based immunotherapy. Using recombinant TCRs, a population of activated T cells can now be redirected to recognize and lyse cellular targets according to the specificity afforded by the transduced TCR genes. To examine the range of lytic activity displayed by the transduced TCRs, transduced T cells were re‐cloned by limiting dilution and quantitatively analysed for lytic activity. The lytic activity of the transduced TCRs varied considerably, as determined by the Km and Vmax of lysis. The lytic activity seen in the secondary clones generated from vector‐transduced peripheral blood mononuclear cell demonstrated that one of the clones approached the lytic activity of the parental ‘TCR donor’ cytotoxic T‐cell lymphocyte (CTL) clone, whereas the remainder demonstrated either reduced Vmax or reduced Vmax and Km. Thus, the lytic activity of a transduced TCR depends not only on its genetic sequence but also on the cellular context within which it is expressed. Analysis of TCR Vβ transcript levels by real time polymerase chain reaction revealed that while total Vβ gene expression was fairly constant, expression of the retrovirally transduced Vβ chain varied greatly in transduced CD8+ CTL clones.
Palaeoenvironmental reconstruction of a middle Miocene alluvial fan to cyclic shallow lacustrine depositional system in the Calatayud Basin (NE Spain)
Authors: Abdul Aziz Hayfaa , Sanz‐Rubio Enrique , Calvo Jose P. , Hilgen Fredirik J. , Krijgsman Wout
Published: December 2004

ABSTRACT The middle Miocene sedimentary fill of the Calatayud Basin in north‐eastern Spain consists of proximal to distal alluvial fan‐floodplain and shallow lacustrine deposits. Four main facies groups characteristic of different sedimentary environments are recognized: (1) proximal and medial alluvial fan facies that comprise clast‐supported gravel and subordinate sandstone and mudstone, the latter exhibiting incipient pedogenic features; (2) distal alluvial fan facies, formed mainly of massive mudstone, carbonate‐rich palaeosols and local carbonate pond deposits; (3) lake margin facies, which show two distinct lithofacies associations depending on their distribution relative to the alluvial fan system, i.e. front (lithofacies A), comprising massive siliciclastic mudstone and tabular carbonates, or lateral (lithofacies B) showing laminated and/or massive siliciclastic mudstone alternating with tabular and/or laminated carbonate beds; and (4) mudflat–shallow lake facies showing a remarkable cyclical alternation of green‐grey and/or red siliciclastic mudstone units and white dolomitic carbonate beds. The cyclic mudflat–shallow lake succession, as exposed in the Orera composite section (OCS), is dominantly composed of small‐scale mudstone–carbonate/dolomite cycles. The mudstone intervals of the sedimentary cycles are interpreted as a result of sedimentation from suspension by distal sheet floods, the deposits evolving either under subaerial exposure or water‐saturated conditions, depending on their location on the lacustrine mudflat and on climate. The dolomite intervals accumulated during lake‐level highstands with Mg‐rich waters becoming increasingly concentrated. Lowstand to highstand lake‐level changes indicated by the mudstone/dolomite units of the small‐scale cycles reflect a climate control (from dry to wet conditions) on the sedimentation in the area. The spatial distribution of the different lithofacies implies that deposition of the small‐scale cycles took place in a low‐gradient, shallow lake basin located in an interfan zone. The development of the basin was constrained by gradual alluvial fan aggradation. Additional support for the palaeoenvironmental interpretation is derived from the isotopic compositions of carbonates from the various lithofacies that show a wide range of δ18O and δ13C values varying from −7·9 to 3·0‰ PDB and from −9·2 to −1·7‰ PDB respectively. More negative δ18O and δ13C values are from carbonate‐rich palaeosols and lake‐margin carbonates, which extended in front of the alluvial fan systems, whereas more positive values correspond to dolomite beds deposited in the shallow lacustrine environment. The results show a clear trend of δ18O enrichment in the carbonates from lake margin to the centre of the shallow lake basin, thereby also demonstrating that the lake evolved under hydrologically closed conditions.
Field measurement and numerical modelling of aeolian mass flux distributions on a sandy beach
Authors: Namikas Steven L.
Published: December 2004

ABSTRACT The vertical and horizontal distributions of aeolian mass flux were measured at Oceano Dunes, California, and these data were used to evaluate a numerical model of saltation. Grain‐size analyses showed that the distributions of the modal sediment size class corresponded closely to those of the total sediment population, and modelling thus focused on replicating the distributions of the mean grain size. Although much previous work has assumed that the mean launch speed of saltating particles varies in proportion to shear velocity, simulations using a constant mean launch speed were found to yield the closest approximations to the mass flux distributions observed in the field. Both exponential and gamma distributions of launch velocity produced realistic simulations, although the latter approach required the inclusion of an additional reptation component to achieve good results. A range of mean launch angles and an equivalent sphere correction were also found to generate comparable results, providing the other input parameters could be varied freely. All the modelling approaches overestimated the proportion of mass flux occurring at the bottom of the vertical distributions, and underestimated the proportion occurring at the upwind end of the horizontal distributions. No theoretical shortcoming that would account for these small, but systematic, discrepancies could be identified, and experimental error thus represents a more plausible explanation. The conclusion that mean grain launch speeds are essentially constant and independent of shear velocity suggests that the additional kinetic energy extracted by grains under more energetic wind conditions is largely transferred to the bed, and that increases in the transport rate are therefore driven primarily by the ejection of additional grains. It is suggested that the kinetic energy of rebounding grains is constrained by the ability of the bed to resist deformation, equivalent to a plastic limit. Hence, grains of larger mass (diameter) rebound from the bed at lower speeds, and follow shorter, lower trajectories, as has been widely observed previously.
Deep to shallow lacustrine evaporites in the Libros Gypsum (southern Teruel Basin, Miocene, NE Spain): an occurrence of pelletal gypsum rhythmites
Authors: Ortí Federico , Rosell Laura , AnadÓN Pere
Published: December 2004

ABSTRACT A number of non‐marine evaporite units composed of primary gypsum were deposited in saline lakes that developed in the southern Teruel Basin (NE Spain) during the Miocene. In the basin depocentre, a continuum of lacustrine evaporite lithofacies influenced by the activity of organisms is displayed. The Libros Gypsum was deposited in a deep lake, in which water stratification became unstable with progressive shoaling. Rhythmites, composed of laminae of pelletal gypsum and laminae of very fine lenticular gypsum crystals mixed with siliceous microorganisms, formed in addition to gypsum turbidites, intraformational gypsum breccias and slump structures. The pelletal laminae originated from the faecal activity of animals (crustaceans?) ingesting gypsum crystallites in the lake water during episodes of maximum evaporation, whereas the laminae of very fine lenticular gypsum mixed with microorganisms accumulated during episodes of relative dilution. In the wide marginal zones of the basin, the Libros Gypsum unit consists of massive to thin‐bedded bioturbated gypsum and thin‐bedded clotted gypsum, which formed in intermediate to very shallow (palustrine) water depths. The bioturbated gypsum lithofacies were produced by the action of diverse organisms, presumably worms and coleopterans, and chironomid larvae to a lesser extent; the massive lithofacies precipitated in very shallow water; and the thin‐bedded lithofacies formed in shallow to deeper settings. The thin‐bedded clotted gypsum is a relatively deep facies that may have diverse origins (e.g. bioturbation, compaction, disruption of soft sediments and early diagenesis). There is a well‐developed metre‐scale cyclicity in the marginal lake sequences, which is not observed in the inner lake deposits. This suggests a depth control in the various lacustrine subenvironments to record cyclic evaporitic processes. The isotopic composition of the gypsum indicates early sulphate‐reducing bacterial activity in the bottom of the lake and suggests that the sulphate was derived from the chemical recycling of Triassic evaporites of the country rocks.
Provenance analysis and tectonic setting of the Ordovician clastic deposits in the southern Puna Basin, NW Argentina
Authors: Zimmermann Udo , Bahlburg Heinrich
Published: December 2004

Provenance studies on Early to Middle Ordovician clastic formations of the southern Puna basin in north‐western Argentina indicate that the sedimentary detritus is generally composed of reworked crustal material. Tremadoc quartz‐rich turbidites (Tolar Chico Formation, mean composition Qt89 F7 L4) are followed by volcaniclastic rocks and greywackes (Tolillar Formation, mean Qt33 F42 L25). These are in turn overlain by volcaniclastic deposits (mean Qt24 F30 L46) of the Diablo Formation (late Arenig–early Llanvirn) that are intercalated by lava flows. All units were deformed in the Oclóyic Orogeny during the Middle and Late Ordovician. Sandstones of the Tolar Chico Formation are characterized by Th/Sc ratios > 1, La/Sc ratios ≈ 10, whereas associated fine‐grained wackes show slightly lower values for both ratios. LREE (light rare earth elements) enrichment of the arenites is ≈ 50× chondrite, Eu/Eu* values are between 0·72 and 0·92, and flat HREE (heavy rare earth elements) patterns indicate a derivation from mostly felsic rocks of typical upper crustal composition. The εNd(t = sed) values scatter around −11 to −9. The calculated Nd‐TDM residence ages vary between 1·8 and 2·0 Ga indicating contribution by a Palaeoproterozoic crustal component. The Th/Sc and La/Sc ratios of the Tolillar Formation are lower than those of the Tolar Chico Formation. Normalized REE (rare earth elements) patterns display a similar shape to PAAS (post‐Archaean average Australian shale) but with higher abundances of HREEs. Eu/Eu* values range between 0·44 and 1·17, where the higher values reflect the abundance of plagioclase and feldspar‐bearing volcanic lithoclasts. Average εNd(t = sed) values are less negative at −5·1, and Nd‐TDM are lower at 1·6 Ga. This is consistent with characteristics of regional rocks of upper continental crust composition, which most probably represent the sources of the studied detritus. The rocks of the Diablo Formation have the lowest Th/Sc and La/Sc ratios, lower LREE abundances than the average continental crust and are slightly enriched in HREEs. Eu/Eu* values are between 0·63 and 1·17. The Nd isotopes (εNd(t = sed) = −3 to −1; TDM = 1·2 Ga) indicate that one source component was less fractionated than both the underlying Early Ordovician and the overlying Middle Ordovician units. Synsedimentary vulcanites in the Diablo Formation show the same isotopic composition. Our data indicate that the sedimentary detritus is generally composed of reworked crustal material, but that the Diablo Formation appears to contain ≈ 80% of a less fractionated component, derived from a contemporaneous continental volcanic arc. There are no data indicating an exotic detrital source or the accretion of an exotic block at this part of the Gondwana margin during the Ordovician.
‘Pseudobreccias’ revealed as calcrete mottling and bioturbation in the Late Dinantian of the southern Lake District, UK
Authors: Horbury Andrew D. , Qing Hairuo
Published: December 2004

Two types of ‘pseudobreccia’, one with grey and the other with brown mottle fabrics, occur in shoaling‐upward cycles of the Urswick Limestone Formation of Asbian (Late Dinantian, Carboniferous) age in the southern Lake District, UK. The grey mottle pseudobreccia occurs in cycle‐base packstones and developed after backfilling and abandonment of Thalassinoides burrow systems. Burrow infills consist of a fine to coarse crystalline microspar that has dull brown to moderate orange colours under cathodoluminescence. Mottling formed when an early diagenetic ‘aerobic decay clock’ operating on buried organic material was stopped, and sediment entered the sulphate reduction zone. This probably occurred during progradation of grainstone shoal facies, after which there was initial exposure to meteoric water. Microspar calcites then formed rapidly as a result of aragonite stabilization. The precipitation of the main meteoric cements and aragonite bioclast dissolution post‐date this stabilisation event. The brown mottle pseudobreccia fabrics are intimately associated with rhizocretions and calcrete, which developed beneath palaeokarstic surfaces capping cycle‐top grainstones and post‐date all depositional fabrics, although they may also follow primary depositional heterogeneities such as burrows. They consist of coarse, inclusion‐rich, microspar calcites that are always very dull to non‐luminescent under cathodoluminescence, sometimes with some thin bright zones. These are interpreted as capillary rise and pedogenic calcrete precipitates. The δ18O values (−5‰ to −8‰, PDB) and the δ13C values (+2‰ to −3‰, PDB) of the ‘pseudobreccias’ are lower than the estimated δ18O values (−3‰ to −1‰ PDB) and δ13C values of (+2‰ to +4‰ PDB) of normal marine calcite precipitated from Late Dinantian sea water, reflecting the influence of meteoric waters and the input of organic carbon.
Thresholds of aeolian sand transport: establishing suitable values
Authors: Wiggs G.f.S. , Atherton R.J. , Baird A.J.
Published: December 2004

This paper assesses the practical use and applicability of the time fraction equivalence method (TFEM; Stout & Zobeck, 1996) of calculating a wind speed threshold for sand grain entrainment in field situations. A modification of the original method is used and is applied to 1 Hz measurements of wind speed and sand transport on a beach surface. Calculated grain entrainment thresholds are tested in terms of the percentage of sand transport events that they explain. It was found that the calculated thresholds offered a poor representation of the occurrence of saltation activity, explaining only about 50% of the measured transport events. Results are discussed in terms of system response time, wind speed measurement height, undetected events and sampling period. A shear velocity threshold for grain entrainment was also calculated, but this also failed to explain a high proportion of the sand transport events. The best results (67–91% of transport events explained) were found by calculating a threshold based on time‐averaged (≈ 40 s) wind velocity measurements. The applicability of a single threshold to a natural grain population is discussed. A natural surface is likely to possess a range of thresholds varying over short time scales in response to parameters such as grain rearrangement and changes in moisture conditions. The results show that calculated thresholds based on 40 s time‐averaged data consistently explain a high proportion of the recorded sand transport events. This is because such a time‐averaged approach accounts for higher frequency variability inherent in the sand transport system.
Low‐grade metamorphic alteration of feldspar minerals: a CL study
Authors: Leichmann J. , Broska I. , Zachovalová K.
Published: December 2004

ABSTRACT Two styles of feldspar alteration – carbonatization and albitization – were investigated using a cathodoluminescence (CL) technique. The nature of the alteration depends on the composition of the fluids. The infiltration of CO2‐rich fluids causes decomposition of An‐rich zones in plagioclase followed by the formation of secondary calcite, albite and white mica. K‐feldspar is more resistant to CO2‐induced alteration. The circulation of aqueous fluids results in decomposition of primary oligoclase into albite and clinozoisite. Secondary K‐feldspar exsolved as small independent grains on the rim of the primary oligoclase, if the primary plagioclase was enriched in the orthoclase component. The fluids easily penetrate the crystals using, crystallographic plains, e.g., twinning or cleavage or simply along cracks. These migration pathways enable the fluids to enter the inner parts of the grain, which would otherwise not be affected by grain‐surface alteration.
Pleistocene/Holocene climate change, re‐establishment of fluvial drainage network and increase in relief in the Swiss Alps
Authors: Schlunegger Fritz , Hinderer Matthias
Published: December 2004

ABSTRACT Data are presented about modern sediment discharge of the Swiss rivers and related to the size of catchments. The information reveals that the Central Alps have experienced denudation rates of ≈0.15 mm yr−1 in the foreland, and ≈0.5 mm yr−1 in the Alpine core. Mapping, however, indicates that modern erosion only affects 30–50% of the Alpine surface, and that fluvial and associated hillslope processes have focused erosion in 50–200‐m‐deep valleys. These valleys are incised into the glacial surface. If this limited spatial extent of erosion is considered, then effective erosion rates are significantly higher than average denudation rates. These effective rates equal or locally exceed modern rates of rock uplift. This implies that the modification of erosional processes related to the Pleistocene/Holocene climate change has resulted in an increase in the relief at a local scale. At a drainage basin scale, however, the relief appears not to change at present.