bluuebunny/crossref_metadata_2025 huggingface dataset:
Predictors of mortality among HIV infected patients taking antiretroviral treatment in Ethiopia: a retrospective cohort study
Authors: Biadgilign Sibhatu , Reda Ayalu A , Digaffe Tesfaye
Published: May 2012

Background

Studies indicate that there is high early mortality among patients starting antiretroviral treatment in sub-Saharan Africa. However, there is paucity of evidence on long term survival of patients on anti-retroviral treatment in the region. The objective of this study is to examine mortality and its predictors among a cohort of HIV infected patients on anti-retroviral treatment retrospectively followed for five years.

Methods

A retrospective cohort study was conducted among HIV infected patients on ART in eastern Ethiopia. Cox regression and Kaplan-Meier analyses were performed to investigate factors that influence time to death and survival over time.

Result

A total of 1540 study participants were included in the study. From the registered patients in the cohort, the outcome of patients as active, deceased, lost to follow up and transfer out was 1005 (67.2%), 86 (5.9%), 210 (14.0%) and 192 (12.8%) respectively. The overall mortality rate provides an incidence density of 2.03 deaths per 100 person years (95% CI 1.64 - 2.50). Out of a total of 86 deaths over 60 month period; 63 (73.3%) died during the first 12 months, 10 (11.6%) during the second year, and 10 (11.6%) in the third year of follow up. In multivariate analysis, the independent predictors for mortality were loss of more 10% weight loss, bedridden functional status at baseline, ≤ 200 CD4 cell count/ml, and advanced WHO stage patients.

Conclusion

A lower level of mortality was detected among the cohort of patients on antiretroviral treatment in eastern Ethiopia. Previous history of weight loss, bedridden functional status at baseline, low CD4 cell count and advanced WHO status patients had a higher risk of death. Early initiation of ART, provision of nutritional support and strengthening of the food by prescription initiative, and counseling of patients for early presentation to treatment is recommended.
Survivin regulates the expression of VEGF-C in lymphatic metastasis of breast cancer
Authors: Cai Xiaopeng , Ma Shuai , Gu Ming , Zu Cong , Qu Wenzhi , Zheng Xinyu
Published: May 2012

Background

As a known regulator of apoptosis, survivin has positive relationship with lymphatic metastasis in breast cancer. This study aims to detect the difference in expression between survivin and vascular endothelial growth factor-C (VEGF-C) in treated breast cancer cells and tissues, and to analyze the correlation among survivin, VEGF-C and lymphatic metastasis.

Methods

Plasmid with survivin and VEGF-C shRNA and lentivirus with survivin gene were constructed and transfected into breast cancer cell ZR-75-30. Then the expressions of the two genes were examined using western blot analysis and real-time PCR. The change of invasiveness of breast cancer cells was assessed using matrigel invasion assay. Using immunohistochemistry, the expression of survivin and VEGF-C were analyzed in 108 clinical breast cancer cases with breast cancer tissue and lymph node.

Results

Survivin regulated the expression of VEGF-C at both protein and mRNA levels in breast cancer cells. Immunohistochemical analysis showed that the level of VEGF-C expression was significantly related with that of survivin in breast cancer tissues (p<0.05). VEGF-C was found to participate in the process of breast cancer cells invasion mediated by survivin. The co-expression of the two and the single expression of any one took significant difference in positive lymph node (p<0.05).

Conclusions

Survivin takes an important part in regulating the expression of VEGF-C. VEGF-C could influence the invasive ability mediated by survivin. The co-expression of survivin and VEGF-C is more statistically significant to assess lymphatic metastasis in breast cancer.

Virtual slides

The virtual slide(s) for this article can be found here:http://www.diagnosticpathology.diagnomx.eu/vs/9193530897100952
Polycystic ovary syndrome resembling histopathological alterations in ovaries from prenatal androgenized female rats
Authors: Wang Fang , Yu Bolan , Yang Wenjing , Liu Jianqiao , Lu Jiachun , Xia Xuefeng
Published: May 2012

Background

The polycystic ovary syndrome ( PCOS) affects approximately 6-10% of women of reproductive age and is characterized by chronic anovulation and hyperandrogenism. However, a comprehensive understanding of the mechanisms that dictate androgen overproduction is lacking, which may account for inconsistencies between measures of androgen excess and clinical presentation in individual cases.

Methods

A rat model of PCOS was established by injecting dehydroepiandrosterone sulfoconjugate (DHEAS) into pregnant females. Rats were administered with DHEAS (60 mg/kg/d) subcutaneously (s.c.) for all 20 days of pregnancy (Group A), or for the first 10 days (Group B), or from day 11 to day 20 (Group C). Controls were administered with injection oil (0.2 ml/day) s.c. throughout pregnancy (Group D). The litter rate, abortion rate, and offspring survival rate in each group were recorded. Serum androgen and estrogen were measured and the morphological features of the ovaries were examined by light and electron microscopy in the offspring of each group.

Results

We found that rats injected with DHEAS throughout pregnancy (group A) lost fertility. Rats injected with DHEAS during early pregnancy (group B) exhibited more serious aberrations in fertility than both Group C, in which rats were injected with DHEAS during late pregnancy (P < 0.05), and Group D (controls). There was a statistical difference of ovarian weight among female offspring in Group B, C and D (P < 0.01). By light and electron microscopy, a significant morphological difference among the female offspring in the three groups was observed.

Conclusions

Our results indicate that androgen excess during pregnancy can decrease rat fertility. Excess androgen at the early stage of pregnancy causes high reproductive toxicity, leading to abnormality of ovarian morphology and functions in female offspring.
Outcome of match related allogeneic stem cell transplantation procedures performed from 2004 till 2011
Authors: Ali Natasha , Adil Salman Naseem , Shaikh Mohammad Usman , Moosajee Munira , Masood Nehal
Published: May 2012

We present our initial experience of allogeneic stem cell transplant procedure performed between April 2004 and August 2011 for various haematological disorders. All patients with non-malignant and malignant haematological disorders with HLA matched donors were selected after pre-transplant workup. Ninety seven patients underwent the procedure. Most common indications for transplant were aplastic anaemia in n = 34 (35%), followed by β-Thalassemia major in n = 21 (21.6%) and chronic myeloid leukemia in n = 11 patients (11.3%). Primary graft failure present was present in 2.06%. Incidence of graft versus host disease (GvHD) in our patients was 34%. After median follow-up of five years the overall survival was 71.3% with a mean survival time of 51.2 ± 3.3 months.
C-Type Natriuretic Peptide Stimulates Ovarian Follicle Development
Authors: Sato Yorino , Cheng Yuan , Kawamura Kazuhiro , Takae Seido , Hsueh Aaron J.W.
Published: May 2012

C-type natriuretic peptide (CNP) encoded by the NPPC (Natriuretic Peptide Precursor C) gene expressed in ovarian granulosa cells inhibits oocyte maturation by activating the natriuretic peptide receptor (NPR)B (NPRB) in cumulus cells. RT-PCR analyses indicated increased NPPC and NPRB expression during ovarian development and follicle growth, associated with increases in ovarian CNP peptides in mice. In cultured somatic cells from infantile ovaries and granulosa cells from prepubertal animals, treatment with CNP stimulated cGMP production. Also, treatment of cultured preantral follicles with CNP stimulated follicle growth whereas treatment of cultured ovarian explants from infantile mice with CNP, similar to FSH, increased ovarian weight gain that was associated with the development of primary and early secondary follicles to the late secondary stage. Of interest, treatment with FSH increased levels of NPPC, but not NPRB, transcripts in ovarian explants. In vivo studies further indicated that daily injections of infantile mice with CNP for 4 d promoted ovarian growth, allowing successful ovulation induction by gonadotropins. In prepubertal mice, CNP treatment alone also promoted early antral follicle growth to the preovulatory stage, leading to efficient ovulation induction by LH/human chorionic gonadotropin. Mature oocytes retrieved after CNP treatment could be fertilized in vitro and developed into blastocysts, allowing the delivery of viable offspring. Thus, CNP secreted by growing follicles is capable of stimulating preantral and antral follicle growth. In place of FSH, CNP treatment could provide an alternative therapy for female infertility.
Terrorism and Patriotism: On the Earnings of US Veterans following September 11, 2001
Authors: Dávila Alberto , Mora Marie T
Published: May 2012

Using data from the 2000 census and the 2001-08 American Community Surveys, this paper examines the impact of 9/11 on the earnings of US veteran men. Our hypothesis is that the surge in patriotism after 9/11 improved their relative earnings, but this earnings effect was short-lived. In addition, we further consider whether this effect was equally felt across race/ethnicity and along regional dimensions. Consistent with our hypothesis, we find a significant short-term improvement in the relative earnings of US veteran men following 9/11. However, additional analyses suggest that this earnings effect did not evenly occur across demographic and geographic dimensions.
Efficient Auctions and Interdependent Types
Authors: Bergemann Dirk , Morris Stephen , Takahashi Satoru
Published: May 2012

We consider the efficient allocation of a single good with interdependent values in a quasilinear environment. We present an approach to modeling interdependent preferences distinguishing between “payoff types” and “belief types” and report a characterization of when the efficient allocation can be partially Bayesian implemented on a finite type space. The characterization can be used to unify a number of sufficient conditions for efficient partial implementation in this classical auction setting. We report how a canonical language for discussing interdependent types - developed in a more general setting by Bergemann, Morris and Takahashi (2011) - applies in this setting and note by example that this canonical language will not allow us to distinguish some types in the payoff type - belief type language.
Prospect Theory as Efficient Perceptual Distortion
Authors: Woodford Michael
Published: May 2012

The paper proposes a theory of efficient perceptual distortions, in which the statistical relation between subjective perceptions and the objective state minimizes the error of the state estimate, subject to a constraint on information processing capacity. The theory is shown to account for observed limits to the accuracy of visual perception, and then postulated to apply to perception of options in economic choice situations as well. When applied to choice between lotteries, it implies reference-dependent valuations, and predicts both risk-aversion with respect to gains and risk-seeking with respect to losses, as in the prospect theory of Kahneman and Tversky (1979).
Trade, Labor Market Frictions, and Residual Wage Inequality across Worker Groups
Authors: Krishna Pravin , Poole Jennifer P , Senses Mine Zeynep
Published: May 2012

Using a matched employer-employee data set, we study the effects of trade liberalization on wage dispersion in Brazil across heterogeneous worker groups, keeping in mind that the assignment of workers to firms may be non-random and determined by the time-invariant productivity of workers specific to the firms with which they are matched. We find differential effects of trade reform on residual wage inequality across worker groups. High education workers experience greater increases in wage dispersion relative to low education workers following trade liberalization. This finding is broadly consistent with the theoretical predictions that emerge from models with heterogeneous firms, heterogeneous workers, and labor market frictions.
Hand osteoarthritis
Authors: Falconer Judith
Published: May 2012

This short report presents a view of osteoarthritis (OA) as cumulative microtrauma mediated by physical activity. The view, grounded in principles of hand pathomechanics, places physical activity at the centre of the process through which problems in the joint (originating from many possible sources) result in a cascade of symptoms and hand impairments. The view points towards opportunities to expand treatment options and improve treatment outcomes for patients with hand OA.
Gonadotrophin receptor hormone analogues in combination with add-back therapy: an update
Authors: McLaren James Samuel , Morris Edward , Rymer Janice
Published: May 2012

Gonadotrophin receptor hormone analogues (GnRHa) have been used in a range of sex hormone-dependent disorders. In the management of premenstrual syndrome, they can completely abolish symptoms. The success of GnRHa in the treatment of endometriosis and adjuvant therapy in the management of fibroids is proven. This efficacy does not come without a cost and the side-effects of the hypo-estrogenic state have limited their application. The use of add-back therapy to counter these effects has enabled wider application, longer durations of treatment and an increase in compliance. This review article is an update on the evidence supporting gonadotrophin receptor hormone analogues in combination with add-back therapy.
Psychotropic medications and other non-hormonal treatments for premenstrual disorders
Authors: Pearlstein Teri
Published: May 2012

Selective serotonin re-uptake inhibitors have well-established efficacy for severe premenstrual syndrome and premenstrual dysphoric disorder. Efficacy has been reported with both continuous dosing (all cycle) and intermittent or luteal phase dosing (from ovulation to menses). Efficacy may be less with intermittent dosing, particularly for premenstrual physical symptoms. The efficacy of symptom-onset dosing (medication taken only on luteal days when symptoms occur) needs further systematic study. Women going through the menopausal transition may need to adjust their antidepressant dosing regimen due to the change in frequency of menstruation. Anxiolytics, calcium, chasteberry and cognitive-behaviour therapy may also have a role in the treatment of premenstrual symptoms.
Treatment of premenstrual disorders by suppression of ovulation by transdermal estrogens
Authors: Studd John
Published: May 2012

The understanding of the cause and treatment of premenstrual disorders is confused but it is essentially the result of cyclical ovarian activity, usually ovulation, and an effective treatment should be by suppressing ovulation. This can be done by an oral contraceptive but as these women are progestogen intolerant the symptoms may persist becoming constant rather than cyclical. Alternatively, transdermal estradiol by patch, gel or implant effectively removes the cyclical hormonal changes, which produce the cyclical symptoms. A shortened seven-day course of a progestogen is required each month for endometrial protection but it can reproduce premenstrual syndrome-type symptoms in these women. Gonadotropin-releasing hormone with ‘add-back’ is effective in the short term. Laparoscopic hysterectomy and bilateral oophorectomy with adequate replacement of estrogen and testosterone should be considered in the severe cases with progestogenic side-effects.
Potential strategies to avoid progestogen-induced premenstrual disorders
Authors: Baker Lucy J , O'Brien P M S
Published: May 2012

Non-hormonal approaches to premenstrual syndrome (PMS) treatment such as selective serotonin reuptake inhibitors are by no means effective for all women and frequently we must resort to endocrine therapy. During many of the hormonal approaches, PMS-like symptoms can be introduced or re-introduced during the necessary cyclical or continuous progestogen component of the therapy. This is seen with combined oral contraception, progestogen only contraception, progestogen therapy for heavy menstrual bleeding and endometriosis, sequential hormone replacement therapy and any therapeutic strategy for premenstrual syndrome where it is necessary to provide endometrial protection, including estrogen suppression of ovulation or add-back during gonadotrophin releasing hormone suppression. The link to progestogen is very often missed by health professionals. When the pattern of symptoms mimics the cyclicity of PMS, it is termed progestogen-induced premenstrual disorder. The need to use progestogen to protect the endometrium from the proliferative actions of estrogen can pose insurmountable difficulties in managing premenstrual disorders. In the absence of any really useful evidence, nearly all practice in this area depends on clinician experience. We cannot afford to wait for adequate research evidence to be produced – it never will – and so we must rely on empirical findings, clinical experience, theoretical strategies and common sense.
Classification of premenstrual disorders as proposed by the International Society for Premenstrual Disorders
Authors: Kadian Suman , O'Brien Shaughn
Published: May 2012

Premenstrual disorders have been recognized as affecting innumerable women for decades but unlike most other medical conditions universally accepted criteria for definition and diagnosis are not established. Although premenstrual syndrome (PMS) occurs throughout reproductive life, there are some women who become particularly troubled. Those approaching the menopause may also have a mixture of PMS and menopause symptoms, not to mention heavy periods. Furthermore, some of the symptoms are similar in nature and so it is a challenge to identify which set of symptoms belongs to which spectrum. This is an area that has not been explored well. Various classifications have been proposed over the last few decades. A further effort towards the classification was made by an international multidisciplinary group of experts established as the International Society for Premenstrual Disorders (ISPMD) in Montreal in September 2008. Their deliberations resulted in a unified diagnosis, classification of premenstrual disorders (PMD) along with their quantification and guidelines on clinical trial design. This classification of PMS is far more comprehensive and inclusive than previous attempts. PMD in the ISPMD Montreal consensus are divided into two categories: Core and Variant PMD. Core PMD are typical, pure or reference disorders associated with spontaneous ovulatory menstrual cycles while Variant PMD exist where more complex features are present. Further, the consensus group considered that PMD may be subdivided into three subgroups predominantly physical, predominantly psychological and mixed. Variant PMD encompass primarily four different types; premenstrual exacerbation, PMD with anovulatory ovarian activity, PMD with absent menstruation and progestogen-induced PMD.
Severe premenstrual syndrome and bipolar disorder: a tragic confusion
Authors: Studd John
Published: May 2012

Bipolar disorder and severe premenstrual syndrome (PMS) have many symptoms in common, but it is important to establish the correct diagnosis between a severe psychiatric disorder and an endocrine disorder appropriately treatable with hormones. The measurement of hormone levels is not helpful in making this distinction, as they are all premenopausal women with normal follicle-stimulating hormone and estradiol levels. The diagnosis of PMS should come from the history relating the occurrence of cyclical mood and behaviour changes with menstruation, the improvement during pregnancy, postnatal depression and the presence of runs of many good days a month and the somatic symptoms of mastalgia, bloating and headaches. Young women with severe PMS do not respond to the antidepressants and mood-stabilizing drugs typically used for bipolar disorder.
Treatment of premenstrual syndrome: a decision-making algorithm
Authors: Panay Nick
Published: May 2012

The aim of this short paper will be to guide the clinician through the plethora of possible interventions to help them to individualize treatment for their patients with PMS. The discussion will highlight management principles rather than evidence per se. It uses as its basis an updated version of the treatment algorithm published by the RCOG in its Green Top Guideline no. 48 on the management of PMS.
Zero-Sum Risk-Sensitive Stochastic Differential Games
Authors: Basu Arnab , Ghosh Mrinal K.
Published: May 2012

We study zero-sum risk-sensitive stochastic differential games on the infinite horizon with discounted and ergodic payoff criteria. Under certain assumptions, we establish the existence of values and saddle-point equilibria. We obtain our results by studying the corresponding Hamilton–Jacobi–Isaacs equations. Finally, we show that the value of the ergodic payoff criterion is a constant multiple of the maximal eigenvalue of the generators of the associated nonlinear semigroups.
Twenty-Five Years of Hub Location Research
Authors: Campbell James F. , O'Kelly Morton E.
Published: May 2012

Last year was the 25th anniversary of two seminal transportation hub location publications, which appeared in 1986 in Transportation Science and Geographical Analysis. Though there are related hub location and network design articles that predate these works, the 1986 publications provided a key impetus for the growth of hub location as a distinct research area. This paper is not intended as a comprehensive review of hub location literature; rather, our goal is to reflect on the origins of hub location research, especially in transportation, and provide some commentary on the present status of the field. We provide insight into early motivations for analyzing hub location problems and describe linkages to problems in location analysis and network design. We also highlight some of the most recent research, discuss some shortcomings of hub location research and suggest promising directions for future effort.
Identification of heat shock protein 60 as the regulator of the hypoxia-inducible factor subunit HIF-1α
Authors: Ban Hyun Seung , Shimizu Kazuki , Minegishi Hidemitsu , Nakamura Hiroyuki
Published: May 2012

The hypoxia-inducible factor (HIF) takes part in transcriptional activation of hypoxia-responsive genes such as vascular endothelial growth factor (VEGF), insulin-like growth factor, and inducible nitric oxide synthase. Since VEGF plays an important role in pathological angiogenesis such as tumor growth and ischemic diseases, the inhibition of VEGF inducer HIF is an attractive approach for the inhibition of pathological angiogenesis. Recently, we have reported that the introduction of boronic acid and a carborane moiety into phenoxyacetanilide induced a potent inhibitory effect on HIF-1α activation under hypoxic conditions. In the present study, to clarify the mechanism of action of carboranylphenoxyacetanilide GN26361 against HIF inhibition, we designed and synthesized molecular probes of GN26361 substituted with benzophenone to induce covalent binding with the target protein by UV (photoaffinity labeling) and an acetylenic moiety to conjugate with the green-fluorescent Alexa Fluor 488-azide by click reaction. In-gel fluorescent imaging of target protein bound with the probe was identified as heat shock protein 60 (HSP60). Moreover, direct binding in gel fluorescent imaging was observed by photoaffinity labeling and click reaction of the probe with recombinant HSP60. These results indicate that HSP60 is the target protein of GN26361 and might be a new molecular target for HIF inhibition.
Special Issue: Labor in American Politics
Authors: La Raja Raymond J. , Shafer Byron E.
Published: May 2012

This special issue of The Forum focuses on the changing place of organized labor in American politics.

In remembrance of James Q. Wilson,
The Return of Judicial Repression: What Has Happened to the Strike?
Authors: Rhomberg Chris
Published: May 2012

Discussions of the current state of American labor have overlooked the fact that the strike, a principal form of union and working class power, has virtually disappeared from American life. The rise of an anti-union institutional legal regime has undermined the right to strike and effectively reversed the structure of incentives for collective bargaining envisioned under the National Labor Relations Act. The dynamics of the current regime are illustrated by one of the largest and longest strikes of recent decades, the 1995 Detroit Newspapers strike. The consequences go beyond unionized labor and constitute a de-democratization of workplace governance in the United States.
Solidarities and Restrictions: Labor and Immigration Policy in the United States
Authors: Fine Janice , Tichenor Daniel J.
Published: May 2012

In American labor’s response to immigration over time, one can observe “a movement wrestling” between restrictionist and solidaristic positions. A crucial transformation of American labor’s response to immigration occurred from the 1930s to the 1960s which is attributed to four factors: changes in the structure and composition of the labor market, shifts in immigration flows, shifts in the attitudes of the labor movement toward immigrants, and the changing disposition of the American state toward unions. In this article we look at the policy choices and dilemmas that have faced the American labor movement since the 1940’s, putting forth a conceptual framework for understanding labor’s shifting positions over time and identifying critical moments in American political development. Having laid this foundation, we move on to a consideration of labor’s most recent positions concerning contemporary policy debates.
The Most Powerful Political Force in the Country
Authors: Siegel Fred
Published: May 2012

The rising power of public sector unions, long overlooked, came into full view with the bitter clash in Wisconsin. But it has been building since the mid-1990s when government unions took the helm of the AFL-CIO. The ground operations of the public sector unions make them an enormous asset for the Democratic Party. But their insatiable demands create conflicts that are difficult to resolve.
Separable ultrametric spaces and their isometry groups
Authors: Malicki Maciej
Published: May 2012

The paper is devoted to a study of isometry groups of Polish ultrametric spaces. We explicitly describe isometry groups of spaces that are non-locally rigid and satisfy the property that distances between orbits under the action of the isometry group are realized by points. The type of group construction appearing here is a variant of the generalized wreath product. We prove that it has a natural universality and uniqueness property. As an application, we characterize Polish ultrametric spaces satisfying the above properties, whose isometry groups have uncountable strong cofinality.
Determination of Porosity Distributions of Water Saturated Granular Media Using Spatial Time Domain Reflectometry (Spatial TDR)
Authors: Scheuermann Alexander
Published: May 2012

A sensor has been developed for the investigation of erosion processes in cylindrical specimens that permits the determination of porosity distributions using spatial time domain reflectometry (spatial TDR). Spherical glass beads saturated with water were used as a model material. The porosity was varied by mixing different size glass beads, and a physical mixing rule was optimized to determine a temperature dependent calibration function between dielectric permittivity and porosity. Homogeneous specimens were used to calibrate the sensor. An inversion algorithm was used for the analysis of the TDR signals. Both the sensor and the procedure were tested using specimens of glass beads comprised of layers with different porosities. The comparison between the measured and predefined porosity distributions shows satisfactory agreement.
Measurement of the Shear Strength of an Expansive Soil by Combining a Filter Paper Method and Direct Shear Tests
Authors: Bai F. Q. , Liu S. H.
Published: May 2012

The measurement of the shear strength of unsaturated soils in terms of two independent stress state variables is usually difficult, expensive, and time-consuming. This paper presents a proposal to combine a filter paper method and a conventional direct shear test to obtain this measurement. The feasibility of this approach is illustrated through tests on an expansive soil. First, the filter paper method is used to establish the soil-water characteristic curve of the soil, and a series of conventional direct shear tests is subsequently conducted to measure the shear strength of the soil. The matric suction of the soil at failure is estimated from the soil-water characteristic curve based on the water content of the soil tested. The test results show that the failure envelopes of the expansive soil are nonlinear on the shear strength versus the matric suction plane for different net normal stresses. The unsaturated shear strength parameter ϕb is equal to the effective friction angle ϕ′ when the soil is close to being saturated, and ϕb decreases as the soil becomes drier. The combined method proposed in this paper may be a practical technique for analyzing the shear strength of unsaturated soils in terms of two independent stress state variables because it can be conducted in most geotechnical laboratories.
A Comparison of Density-Based and Modulus-Based In Situ Test Measurements for Compaction Control
Authors: Meehan Christopher L. , Tehrani Faraz S. , Vahedifard Farshid
Published: May 2012

This paper presents and compares the results from a series of in situ density-based and modulus-based compaction control tests that were conducted during construction of a coarse-grained soil embankment. To simulate current construction practices as closely as possible, these in situ tests were performed on an embankment that was constructed and compacted by a vibratory smooth drum roller in a series of lifts. During construction of the test embankment, the compaction process was monitored using the nuclear density gauge device and a number of alternative modulus-based devices, including the lightweight deflectometer, the dynamic cone penetrometer, and the soil stiffness gauge. Comparison of the in situ test results illustrates that point-to-point variability in measured values is quite common for each of these test devices, to varying degrees for the different devices that were examined. Consistent increases in measured soil properties from pass-to-pass of the compactor are considered critical for proper control of the compaction process, with some devices faring better than others in this area of performance. The measured modulus values correlated poorly to the nuclear density gauge dry unit weights, and also correlated poorly with other measured moduli when the results from different devices were compared. This lack of agreement was likely caused by a variety of factors including: variations in the magnitude of strain and rate of strain application between the different modulus-based devices, variations in the tested volume between the different devices, and variations in the local moisture content and matrix suction conditions. Finally, the effect of soil moisture content was shown to be critically important when interpreting the results from modulus-based tests, and the utility of multiple regression analyses was explored for including this effect.
A Comparative Study on the Shear Behavior of an Interlayer Material Based on Laboratory and In Situ Shear Tests
Authors: Xu Ding-Ping , Feng Xia-Ting , Cui Yu-Jun , Jiang Ya-Li , Huang Ke
Published: May 2012

In order to evaluate the overall stability of the underground powerhouse at the future Baihetan hydropower station in China, the shear strength of a weak intercalation soil in the host rock has been investigated via in situ direct shear and laboratory shear tests. A comparative study was performed based on the two test results. It has been observed that both tests show elastic perfect-plastic behavior. A significant heterogeneity of the samples has been identified under both laboratory and field conditions. The samples’ disturbance seems to be a less important factor than the samples’ variability. The size effect has been evidenced by the friction angle obtained in the laboratory on small samples, which is greater than that obtained in the field on larger samples. The clay fraction has been found to be an important factor; its increase reduces the friction angle and increases the cohesion. Without considering some particular data due to the soil heterogeneity, a negligible effect of the initial degree of saturation has been identified. Comparisons between the results of the field tests and those from the laboratory tests show good consistency in terms of the effects of the clay fraction and the initial degree of saturation, indicating a relatively secondary effect of the sample size and variability.
Apparatus for Constant Rate-of-Strain Consolidation of Slurry Mixed Soils
Authors: Sample Kristin M. , Shackelford Charles D.
Published: May 2012

A constant rate-of-strain (CRS) consolidation apparatus was developed to allow testing of slurry mixed soils prepared within 102-mm (4-in) inner diameter acrylic columns with varying lengths using a laboratory mixing apparatus. The laboratory mixing apparatus was previously developed to mimic the mixing process associated with the use of slurries containing bentonite and granular zero-valent iron (ZVI) for in situ remediation at sites contaminated with chlorinated solvents. Example consolidation results are provided for specimens of dry sand mixed with bentonite-ZVI slurry with lengths of 305 mm (12 in), 457 mm (18 in), or 610 mm (24 in). After mixing, all of the specimens except for the 610-mm specimen were consolidated directly within the same columns to minimize sampling disturbance. The 610-mm specimen was sectioned into thirds before consolidation testing to evaluate effects of vertical heterogeneity. As expected, all specimens were highly compressible, with maximum (large) strains ranging from 10.7 % to 48.0 %. For specimens prepared and tested within the same columns, the effects of differences in column length and strain rate were minor. The CRS testing apparatus offered a convenient, rapid (< 3 day), and economical approach for evaluating the consolidation behavior of the bentonite-ZVI slurry mixed sand.
Discussion on “Stress Concentration Ratio of Model Stone Columns in Soft Clays” by Fattah, M., Shlash, K., and Al-Waily, M., Geotechnical Testing Journal, Vol. 34, No. 1, Paper ID GTJ 103060
Authors: Hamidi Babak
Published: May 2012

The authors state that “Most researchers consider the stone column to behave as a pile. Therefore, the criteria proposed for defining the failure load of the pile can be adopted for stone columns.” The writer does not agree with this statement.
Application of a Hydraulic Gradient Technique for Modeling the Uplift Behavior of Piles in Sand
Authors: Leshchinsky Dov , Vahedifard Farshid , Meehan Christopher L.
Published: May 2012

A scale modeling technique is presented for simulating the uplift behavior of piles in sand, which satisfies stress and strain similitude with full-scale prototypes. A hydraulic gradient approach was used to increase the body forces in the scale model tests, until the stresses became representative of reasonable field-scale conditions. The associated model scaling laws that are used with this technique are presented and discussed. Eight pile pullout tests were conducted, at varying magnitudes of hydraulic gradient; one of these tests was conducted on a pile instrumented with strain gages. From the results of this study, it was concluded that the hydraulic gradient technique can be effectively applied to induce reasonable prototype stresses in a scale model, allowing for reasonable simulation of the uplift behavior of piles in sand. The hydraulic gradient technique was found to be particularly sensitive to the distribution of the hydraulic gradient in the soil profile, which is not surprising, given the nature of the scaling laws for this particular modeling technique. Analysis of the results from the pile instrumented with strain gages indicated that (1) very little shear stress was mobilized in the upper 25 % of the pile, even at applied uplift loads approaching the ultimate pullout force; (2) the largest amount of shear stress for each applied uplift force was typically mobilized at a point somewhere between 60 % and 80 % of the length of the pile; and (3) at failure, the mobilized shear stress distribution was clearly not triangular, as is postulated by commonly used pile uplift design approaches. Post-failure investigations conducted after the completion of each pullout test indicated that the failure shear surface in each of the model tests developed along the pile-soil interface.
A Modified Triaxial Apparatus for Measuring the Stress Path-Dependent Water Retention Curve
Authors: Ng Charles W. W. , Lai C. H. , Chiu C. F.
Published: May 2012

This article reports a modified triaxial apparatus for measuring the stress path-dependent water retention curve (SDWRC) of unsaturated soils under isotropic and deviatoric stress conditions. In this modified triaxial apparatus, an open-ended, bottle-shaped inner cell is installed together with a differential pressure transducer to measure the total volume change of a specimen accurately for the correct determination of the degree of saturation of an SDWRC. Details of the calibration and test procedures are described and discussed. Some test results from compacted samples of a completely decomposed tuff, i.e., silt of low plasticity, are also presented in order to demonstrate the key features of the modified apparatus.
Laboratory Evaluation Method for the Functional Performance of Total Knee Replacements
Authors: Walker Peter S. , Glauber Samuel M. , Wang Haoting
Published: May 2012

In activities of daily living, the normal anatomic knee moves through a range of flexion of up to 155°, and at all angles there are ranges of laxity in both the anterior-posterior direction and internal-external rotation. The ideal situation is that after a total knee replacement (TKR), the knee moves in a similar way, providing normal kinematics, stability, and freedom of motion. Our goal was to formulate a simple standard testing method for evaluating proposed new TKR designs or existing designs that would relate to clinical performance. We developed a Desktop Knee Machine with which combinations of forces and moments were applied to knee models at a range of flexion angles while the neutral path of motion and the laxities about the neutral path were measured. In order to develop and demonstrate the method, three representative TKR types were modeled using computer-assisted design software, and then stereolithographic (SLA) models were made for testing. Different combinations of loads and flexion angles were applied so as to represent a full spectrum of activities and positions. The magnitudes of the forces were less than what would occur in vivo due to the limitations of SLA models, but they were chosen to reach the laxity limits of the TKR models tested. It was concluded that the testing method was a valid and efficient means of comparing the kinematic characteristics of different TKR designs and providing possible indicators of clinical performance.
ASTM F2624-07—Evaluating an Alternate Fixture for Testing Extra Discal Motion Preserving Implants
Authors: Anderson M. C. , Lissy C. J.
Published: May 2012

ASTM F2624-07 prescribes applying flexion/extension, lateral bending, and axial rotation moments to test and evaluate extra discal motion preserving implants (EDMPI). The standard provides a suggested laterally oriented construct (LOC) for conducting flexion/extension (FE) testing. The suggested construct does not have a fixed center of rotation (COR). An alternate set of fixtures to conduct FE testing using a vertically oriented construct (VOC) with a fixed COR is presented. Testing was conducted to quantify the loads applied to an EDMPI using both types of fixtures, quantify shear loading applied to the actuator, determine whether results are frequency dependent, and evaluate whether the fixtures can differentiate between EDMPI using a measure of displacement amplitude. A miniature load cell was mounted to both fixtures to quantify load applied to an EDMPI during testing at several different applied loads or torques and at two testing frequencies (2 Hz and 5 Hz). Lateral actuator shear was measured using a dial indicator. The load cell was replaced with cylindrical test specimens made of stainless steel, titanium, polyether ether ketone, or a polyethylene cable slipped inside a polyurethane tube, and the testing repeated. Results indicated that both fixtures generated similar tensile/compressive loads at an EDMPI. The LOC fixture generated more actuator shear than the VOC. Using a VOC fixture rather than the LOC suggested in ASTM F2624-07 in FE testing may be a reasonable alternative for certain types of devices.
Historical Survey on Ecolabeling Efforts and Criteria for Green Inert or Other Ingredients: EPA Design for the Environment
Authors: Lindner G. , Kaziska A.
Published: May 2012

In addition to the active ingredient, pesticide formulations typically contain surfactants, solvents, diluents, fillers, adjuvant substances, and utility additives such as foam control agents. Over the past several decades, innovations in pesticide formulation have yielded accelerated evolution toward reduced environmental impact and improved sustainability. These provide the key benefits of what are considered “greener” formulations. An example of how this approach manifests in the marketplace is end product ecolabeling as practiced in the consumer products industry. A review of a 2010 global survey of certifying organizations is included in order to provide perspective on how criteria and standards can vary. The range of materials available that might offer either or both the desired reductions in environmental impact and/or improved sustainability varies based on the definition of “green” applied. Important aspects to consider include selecting a definition, deciding which ingredients to use, screening replacements for non-green or less green ingredients, and measuring performance against appropriate benchmarks. Various criteria can be applied in order to define targets for “greener” inert ingredients. The Environmental Protection Agency’s Design for Environment program (DfE) focuses on individual ingredients in addition to formulations. For materials offering similar performance, the underlying chemical, toxicological, or environmental data affect selection. DfE utilizes a third-party ingredient review system (by National Sanitation Foundation [NSF] International and ToxServices) and database (CleanGredients, as managed by GreenBlue) that can provide a basis on which to select materials for evaluation and development as part of formulating safer pesticides with reduced environmental impact and greater sustainability.
Characterization of the Master Curve Based Fracture Toughness of ORNL TSE5 Steel and Unirradiated and Irradiated ASTM A203D 3.5 % Ni Steel by the IGCAR Procedure
Authors: Sreenivasan P. R.
Published: May 2012

The Indira Gandhi Centre for Atomic Research (IGCAR) procedure for predicting the master curve (MC) reference temperature T0 has been further validated via its application to ORNL thermal shock experiment (TSE) 5 steel, an A508 Cl.2 steel that has been widely characterized in the literature. The procedure also was applied to ASTM A203D 3.5% Ni steel tested at IGCAR in virgin and irradiated states. The IGCAR procedure involves the application of the inverse Wallin strain rate equation to TQSchdy, the dynamic reference temperature obtained from Charpy tests using the modified Schindler procedure corresponding to a stress intensity factor rate of ∼106 MPa√m.s−1. A direct correlation of TQSchdy to T0 is also used. The larger of the estimates from these two, namely, TQSchW, provides an accurate and acceptably conservative estimate of the reference temperature TQ-est for steels with TQSchdy ≤ 60°C; for steels with TQSchdy>60°C, TQ-est=the larger of TQSchW and TQM2. The value of TQ-est obtained via the IGCAR procedure is termed TQ-IGC. Mostly, TQM2 gives the most conservative estimate, and TQBT (based on the value of TD obtained from instrumented Charpy V-notch impact tests) has a tendency toward accuracy, provided a robust estimate of TD can be obtained (which is not always the case). The IGCAR procedure was compared with two other conservative lower-bound (LB) procedures (Schindler-LB and Merkle-LB procedures), and it was shown that the IGCAR procedure with a 1% MC provides an LB curve without the difficulties involved in using the more tortuous calculations necessary for applying the Schindler- and Merkle-LB procedures. For the irradiated A203D steel, the shift in the estimated T0 was ΔTQ-IGC=340°C.
Influence Analysis of Application-Specific Phenomena on the Creep-Fatigue Life of Turbine Housings of Turbochargers
Authors: Laengler F. , Mao T. , Scholz A.
Published: May 2012

The turbine housing of a turbocharger is exposed to extensive cyclic thermo-mechanical loading. This leads to multiaxial stress states with local plastifications, so that the design of the turbine housing becomes a major challenge in ensuring the guaranteed lifetime in relation to the high-temperature behavior of the materials. In a first step, a phenomenological lifetime approach in conjunction with a constitutive material model applied in a preceding finite-element analysis was developed and validated for application on the casting materials Ni-resist D5S and vermicular cast iron GJV. The present study deals with the adaption for turbine housing design together with the more detailed analysis of application-specific phenomena to improve the description of both the deformation behavior and the creep-fatigue damage behavior. The influence of different strain rates, mean strain conditions, and aging has been evaluated. Moreover, a critical plane approach has been investigated to handle multiaxial stress and strain states. A more accurate damage ratio is derived by use of specimens subjected to characteristic thermo-mechanical load conditions, which leads to an improved estimation of the cycle number until crack initiation on critical component positions.
Fatigue Crack Growth Rate Behavior of A36 Steel using ASTM Load-Reduction and Compression Precracking Test Methods
Authors: Newman J. C. , Ziegler B. M. , Shaw J. W. , Cordes T. S. , Lingenfelser D. J.
Published: May 2012

Eccentrically-loaded single-edge crack tension, ESE(T), specimens made of A36 structural steel were tested over a wide range in stress ratios (R=0.1 and 0.7) in laboratory air. Two test methods were used: (1) ASTM Standard E647 load-reduction method and (2) compression precracking. After compression precracking (CP), three different loading sequences were used: (1) constant amplitude (CPCA), (2) load reduction (CPLR), and (3) constant stress-intensity factor (CPCK). The crack-compliance method was used to determine that the specimens had no residual stresses; and that the effects of tensile residual stresses from compression precracking dissipated in about 2 compressive plastic-zone sizes. Agreement was found between the A36 and TC-128B steel ΔK-rate data tested at both low and high stress ratio (R) conditions. At R=0.1 loading, the CPCA and CPLR tests generated lower thresholds and faster rates than using the standard ASTM load-reduction method. All load-reduction tests exhibited an accumulation of debris at the crack front near threshold conditions. A crack-closure analysis was preformed to calculate the effective stress-intensity factor range (ΔKeff) against rate using measured 1 % offset (OP1) values for all R=0.1 tests. The ΔKeff-rate data correlated well with the high-R results.