bluuebunny/crossref_metadata_2025 huggingface dataset:
Lipopolysaccharide-induced inflammation attenuates taste progenitor cell proliferation and shortens the life span of taste bud cells
Authors: Cohn Zachary J , Kim Agnes , Huang Liquan , Brand Joseph , Wang Hong
Published: June 2010

Background

The mammalian taste bud, a complex collection of taste sensory cells, supporting cells, and immature basal cells, is the structural unit for detecting taste stimuli in the oral cavity. Even though the cells of the taste bud undergo constant turnover, the structural homeostasis of the bud is maintained by balancing cell proliferation and cell death. Compared with nongustatory lingual epithelial cells, taste cells express higher levels of several inflammatory receptors and signalling proteins. Whether inflammation, an underlying condition in some diseases associated with taste disorders, interferes with taste cell renewal and turnover is unknown. Here we report the effects of lipopolysaccharide (LPS)-induced inflammation on taste progenitor cell proliferation and taste bud cell turnover in mouse taste tissues.

Results

Intraperitoneal injection of LPS rapidly induced expression of several inflammatory cytokines, including tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-6, in mouse circumvallate and foliate papillae. TNF-α and IFN-γ immunoreactivities were preferentially localized to subsets of cells in taste buds. LPS-induced inflammation significantly reduced the number of 5-bromo-2'-deoxyuridine (BrdU)-labeled newborn taste bud cells 1-3 days after LPS injection, suggesting an inhibition of taste bud cell renewal. BrdU pulse-chase experiments showed that BrdU-labeled taste cells had a shorter average life span in LPS-treated mice than in controls. To investigate whether LPS inhibits taste cell renewal by suppressing taste progenitor cell proliferation, we studied the expression of Ki67, a cell proliferation marker. Quantitative real-time RT-PCR revealed that LPS markedly reduced Ki67 mRNA levels in circumvallate and foliate epithelia. Immunofluorescent staining using anti-Ki67 antibodies showed that LPS decreased the number of Ki67-positive cells in the basal regions surrounding circumvallate taste buds, the niche for taste progenitor cells. PCR array experiments showed that the expression of cyclin B2 and E2F1, two key cell cycle regulators, was markedly downregulated by LPS in the circumvallate and foliate epithelia.

Conclusions

Our results show that LPS-induced inflammation inhibits taste progenitor cell proliferation and interferes with taste cell renewal. LPS accelerates cell turnover and modestly shortens the average life span of taste cells. These effects of inflammation may contribute to the development of taste disorders associated with infections.
Does self-management for return to work increase the effectiveness of vocational rehabilitation for chronic compensated musculoskeletal disorders? - Protocol for a randomised controlled trial
Authors: Ellis Niki , Johnston Venerina , Gargett Susan , MacKenzie Alison , Strong Jennifer , Battersby Malcolm , McLeod Rebecca , Adam Keith , Jull Gwendolen
Published: June 2010

Background

Musculoskeletal disorders are common and costly disorders to workers compensation and motor accident insurance systems and are a leading contributor to the burden of ill-health. In Australia, vocational rehabilitation is provided to workers to assist them to stay in, or return to work. Self-management training may be an innovative addition to improve health and employment outcomes from vocational rehabilitation.

Methods/Design

The research plan contains mixed methodology consisting of a single blind randomised controlled trial, an economic evaluation and qualitative research. Participants (n = 366) are volunteers with compensated musculoskeletal disorders of 3 months to 3 years in duration who were working at the time of the injury/onset of the chronic disorder. The trial tests the effectiveness of usual vocational rehabilitation plus the Chronic Disease Self-Management Program (CDSMP) to which two additional and newly-developed modules have been added, against vocational rehabilitation alone (control) The modules added to the CDSMP focus on how to navigate through compensation systems and manage the return to work process, and aim to be relevant to those in a vocational rehabilitation setting.

The primary outcome of this study is readiness for return to work which will be evaluated using the Readiness for Return-to-Work scale. Secondary outcomes include return to work status, health efficacy (heiQ™ questionnaire) and general health status (SF-12v2® Health Survey). Measures will be taken at baseline, immediately post-intervention and at 6- and 12- months post-intervention by an independent assessor. An economic evaluation will compare the costs and outcomes between the intervention and control groups in terms of cost-effectiveness and a partial cost-benefit or cost analysis. The impact of the intervention will also be evaluated qualitatively, in terms of its acceptability to stakeholders.

Discussion

This article describes the protocol for a single blind randomised controlled trial with a one year follow-up. The results will provide evidence for the addition or not of self-management training within vocational rehabilitation for chronic compensated musculoskeletal disorders.

Trial Registration

Australia and New Zealand Clinical Trials Registry ACTRN12609000843257
Native New Zealand plants with inhibitory activity towards Mycobacterium tuberculosis
Authors: Earl Emma A , Altaf Mudassar , Murikoli Rekha V , Swift Simon , O'Toole Ronan
Published: June 2010

Background

Plants have long been investigated as a source of antibiotics and other bioactives for the treatment of human disease. New Zealand contains a diverse and unique flora, however, few of its endemic plants have been used to treat tuberculosis. One plant, Laurelia novae-zelandiae, was reportedly used by indigenous Maori for the treatment of tubercular lesions.

Methods

Laurelia novae-zelandiae and 44 other native plants were tested for direct anti-bacterial activity. Plants were extracted with different solvents and extracts screened for inhibition of the surrogate species, Mycobacterium smegmatis. Active plant samples were then tested for bacteriostatic activity towards M. tuberculosis and other clinically-important species.

Results

Extracts of six native plants were active against M. smegmatis. Many of these were also inhibitory towards M. tuberculosis including Laurelia novae-zelandiae (Pukatea). M. excelsa (Pohutukawa) was the only plant extract tested that was active against Staphylococcus aureus.

Conclusions

Our data provide support for the traditional use of Pukatea in treating tuberculosis. In addition, our analyses indicate that other native plant species possess antibiotic activity.
Composite functional module inference: detecting cooperation between transcriptional regulation and protein interaction by mantel test
Authors: Wu Chao , Zhang Fan , Li Xia , Zhang Shihua , Li Jiang , Su Fei , Li Kongning , Yan Yuqing
Published: June 2010

Background

Functional modules are basic units of cell function, and exploring them is important for understanding the organization, regulation and execution of cell processes. Functional modules in single biological networks (e.g., the protein-protein interaction network), have been the focus of recent studies. Functional modules in the integrated network are composite functional modules, which imply the complex relationships involving multiple biological interaction types, and detect them will help us understand the complexity of cell processes.

Results

We aimed to detect composite functional modules containing co-transcriptional regulation interaction, and protein-protein interaction, in our pre-constructed integrated network of Saccharomyces cerevisiae. We computationally extracted 15 composite functional modules, and found structural consistency between co-transcriptional regulation interaction sub-network and protein-protein interaction sub-network that was well correlated with their functional hierarchy. This type of composite functional modules was compact in structure, and was found to participate in essential cell processes such as oxidative phosphorylation and RNA splicing.

Conclusions

The structure of composite functional modules containing co-transcriptional regulation interaction, and protein-protein interaction reflected the cooperation of transcriptional regulation and protein function implementation, and was indicative of their important roles in essential cell functions. In addition, their structural and functional characteristics were closely related, and suggesting the complexity of the cell regulatory system.
Museum material reveals a frog parasite emergence after the invasion of the cane toad in Australia
Authors: Hartigan Ashlie , Phalen David N , Šlapeta Jan
Published: June 2010

Background

A parasite morphologically indistinguishable fromMyxidium immersum(Myxozoa: Myxosporea) found in gallbladders of the invasive cane toad (Bufo marinus) was identified in Australian frogs. Because no written record exists for such a parasite in Australian endemic frogs in 19thand early 20thcentury, it was assumed that the cane toad introduced this parasite. While we cannot go back in time ourselves, we investigated whether material at the museum of natural history could be used to retrieve parasites, and whether they were infected at the time of their collection (specifically prior to and after the cane toad translocation to Australia in 1935).

Results

Using the herpetological collection at the Australian Museum we showed that no myxospores were found in any animals (n= 115) prior to the cane toad invasion (1879-1935). The green and golden bell frog (Litoria aurea), the Peron's tree frog (Litoria peronii), the green tree frog (Litoria caerulea) and the striped marsh frog (Limnodynastes peronii) were all negative for the presence of the parasite using microscopy of the gallbladder content and its histology. These results were sufficient to conclude that the population was free from this disease (at the expected minimum prevalence of 5%) at 99.7% confidence level using the 115 voucher specimens in the Australian Museum. Similarly, museum specimens (n= 29) of the green and golden bell frog from New Caledonia, where it was introduced in 19thcentury, did not show the presence of myxospores. The earliest specimen positive for myxospores in a gallbladder was a green tree frog from 1966. Myxospores were found in eight (7.1%,n= 112) frogs in the post cane toad introduction period.

Conclusion

Australian wildlife is increasingly under threat, and amphibian decline is one of the most dramatic examples. The museum material proved essential to directly support the evidence of parasite emergence in Australian native frogs. This parasite can be considered one of the luckiest parasites, because it has found an empty niche in Australia. It now flourishes in > 20 endemic and exotic frog species, but its consequences are yet to be fully understood.
Randomized phase II exploratory study of prophylactic amifostine in cancer patients who receive radical radiotherapy to the pelvis
Authors: Katsanos Konstantinos H , Briasoulis Evangelos , Tsekeris Pericles , Batistatou Anna , Bai Maria , Tolis Christos , Capizzello Antonio , Panelos Ioannis , Karavasilis Vasileios , Christodoulou Dimitrios , Tsianos Epameinondas V
Published: June 2010

Background

This study aimed to investigate the efficacy of prophylactic amifostine in reducing the risk of severe radiation colitis in cancer patients receiving radical radiotherapy to the pelvis.

Methods

Patients with pelvic tumours referred for radical radiotherapy who consented participation in this trial, were randomly assigned to receive daily amifostine (A) (subcutaneously, 500 mg flat dose) before radiotherapy or radiotherapy alone (R). Sigmoidoscopy and blinded biopsies were scheduled to conduct prior to initiation and following completion of radiotherapy and again 6 to 9 months later. Radiation colitis was assessed by clinical, endoscopic and histolopathological criteria.

Results

A total 44 patients were enrolled in this trial, the majority with rectal (20 patients) and cervical cancer (12 patients) and were assigned 23 in R arm and 21 in the A arm. In total 119 sigmoidoscopies were performed and 18 patients (18/44, 40.9%) were diagnosed with radiation colitis (15 grade 1 and 2, and 3 grade 3 and 4). Of them, 6 patients belonged to the A group (6/21, 28.6%) and 12 to the R group (12/23, 52.2%). Acute and grade IV radiation colitis was only developed in four patients (17.4%) in the R group. Amifostine side effects were mild. Amifostine treated patients were less likely to develop histologically detectable mucosal lesions, which indicate protection from acute mucosal injury.

Conclusions

Amifostine given subcutaneously can lower the risk of acute severe radiation colitis in patients who receive radical radiotherapy to pelvic tumors.
Peptidyl arginine deiminase type IV (PADI4) haplotypes interact with shared epitope regardless of anti-cyclic citrullinated peptide antibody or erosive joint status in rheumatoid arthritis: a case control study
Authors: Bang So-Young , Han Tae-Un , Choi Chan-Bum , Sung Yoon-Kyoung , Bae Sang-Cheol , Kang Changwon
Published: June 2010

Introduction

Anti-cyclic citrullinated peptide autoantibodies (anti-CCP) are the most specific serologic marker for rheumatoid arthritis (RA). Genetic polymorphisms in a citrullinating (or deiminating) enzyme, peptidyl arginine deiminase type IV (PADI4) have been reproducibly associated with RA susceptibility in several populations. We investigated whether PADI4 polymorphisms contribute to anti-CCP-negative as well as -positive RA, whether they influence disease severity (erosive joint status), and whether they interact with two major risk factors for RA, Human Leukocyte Antigen-DRB1 (HLA-DRB1) shared epitope (SE) alleles and smoking, depending on anti-CCP and erosive joint status.

Methods

All 2,317 unrelated Korean subjects including 1,313 patients with RA and 1,004 unaffected controls were genotyped for three nonsynonymous (padi4_89, padi4_90, and padi4_92) and one synonymous (padi4_104) single-nucleotide polymorphisms (SNPs) in PADI4 and for HLA-DRB1 by direct DNA sequence analysis. Odds ratios (OR) were calculated by multivariate logistic regression. Interaction was evaluated by attributable proportions (AP), with 95% confidence intervals (CI).

Results

A functional haplotype of the three fully correlated nonsynonymous SNPs in PADI4 was significantly associated with susceptibility to not only anti-CCP-positive (adjusted OR 1.73, 95% CI 1.34 to 2.23) but also -negative RA (adjusted OR 1.75, 95% CI 1.15 to 2.68). A strong association with both non-erosive (adjusted OR 1.62, 95% CI 1.29 to 2.05) and erosive RA (adjusted OR 1.62, 95% CI 1.14 to 2.31) was observed for PADI4 haplotype. Gene-gene interactions between the homozygous RA-risk PADI4 haplotype and SE alleles were significant in both anti-CCP-positive (AP 0.45, 95% CI 0.20 to 0.71) and -negative RA (AP 0.61, 95% CI 0.29 to 0.92). Theses interactions were also observed for both non-erosive (AP 0.48, 95% CI 0.25 to 0.72) and erosive RA (AP 0.46, 95% CI 0.14 to 0.78). In contrast, no interaction was observed between smoking and PADI4 polymorphisms.

Conclusions

A haplotype of nonsynonymous SNPs in PADI4 contributes to development of RA regardless of anti-CCP or erosive joint status. The homozygous PADI4 haplotype contribution is affected by gene-gene interactions with HLA-DRB1 SE alleles.
Incidence and prognostic impact of new-onset atrial fibrillation in patients with septic shock: a prospective observational study
Authors: Meierhenrich Rainer , Steinhilber Elisa , Eggermann Christian , Weiss Manfred , Voglic Sami , Bögelein Daniela , Gauss Albrecht , Georgieff Michael , Stahl Wolfgang
Published: June 2010

Introduction

Since data regarding new-onset atrial fibrillation (AF) in septic shock patients are scarce, the purpose of the present study was to evaluate the incidence and prognostic impact of new-onset AF in this patient group.

Methods

We prospectively studied all patients with new-onset AF and all patients suffering from septic shock in a non-cardiac surgical intensive care unit (ICU) during a 13 month period.

Results

During the study period, 687 patients were admitted to the ICU, of which 58 patients were excluded from further analysis due to pre-existing chronic or intermittent AF. In 49 out of the remaining 629 patients (7.8%) new-onset AF occurred and 50 out of the 629 patients suffered from septic shock. 23 out of the 50 patients with septic shock (46%) developed new-onset AF. There was a steady, significant increase in C-reactive protein (CRP) levels before onset of AF in septic shock patients. ICU mortality in septic shock patients with new-onset AF was 10/23 (44%) compared with 6/27 (22%) in septic shock patients with maintained sinus rhythm (SR) (P = 0.14). During a 2-year follow-up there was a trend towards an increased mortality in septic shock patients with new-onset AF, but the difference did not reach statistical significance (P = 0.075). The median length of ICU stay among surviving patients was longer in patients with new-onset AF compared to those with maintained SR (30 versus 17 days, P = 0.017). The success rate to restore SR was 86%. Failure to restore SR was associated with increased ICU mortality (71.4% versus 21.4%, P = 0.015).

Conclusions

AF is a common complication in septic shock patients and is associated with an increased length of ICU stay among surviving patients. The increase in CRP levels before onset of AF may support the hypothesis that systemic inflammation is an important trigger for AF.
Arterial pressure-based cardiac output in septic patients: different accuracy of pulse contour and uncalibrated pressure waveform devices
Authors: Monnet Xavier , Anguel Nadia , Naudin Brice , Jabot Julien , Richard Christian , Teboul Jean-Louis
Published: June 2010

Introduction

We compared the ability of two devices estimating cardiac output from arterial pressure-curve analysis to track the changes in cardiac output measured with transpulmonary thermodilution induced by volume expansion and norepinephrine in sepsis patients.

Methods

In 80 patients with septic circulatory failure, we administered volume expansion (40 patients) or introduced/increased norepinephrine (40 patients). We measured the pulse contour-derived cardiac index (CI) provided by the PiCCO device (CIpc), the arterial pressure waveform-derived CI provided by the Vigileo device (CIpw), and the transpulmonary thermodilution CI (CItd) before and after therapeutic interventions.

Results

The changes in CIpc accurately tracked the changes in CItd induced by volume expansion (bias, -0.20 ± 0.63 L/min/m2) as well as by norepinephrine (bias, -0.05 ± 0.74 L/min/m2). The changes in CIpc accurately detected an increase in CItd ≥ 15% induced by volume expansion and norepinephrine introduction/increase (area under ROC curves, 0.878 (0.736 to 0.960) and 0.924 (0.795 to 0.983), respectively; P < 0.05 versus 0.500 for both). The changes in CIpw were less reliable for tracking the volume-induced changes in CItd (bias, -0.23 ± 0.95 L/min/m2) and norepinephrine-induced changes in CItd (bias, -0.01 ± 1.75 L/min/m2). The changes in CIpw were unable to detect an increase in CItd ≥ 15% induced by volume expansion and norepinephrine introduction/increase (area under ROC curves, 0.564 (0.398 to 0.720) and 0.541 (0.377 to 0.700, respectively, both not significantly different from versus 0.500).

Conclusions

The CIpc was reliable and accurate for assessing the CI changes induced by volume expansion and norepinephrine. By contrast, the CIpw poorly tracked the trends in CI induced by those therapeutic interventions.
FAN (factor associated with neutral sphingomyelinase activation), a moonlighting protein in TNF-R1 signaling
Authors: Montfort Anne , Martin Pascal G P , Levade Thierry , Benoist Hervé , Ségui Bruno
Published: June 2010

Review discusses recent findings on the role of FAN, a TNF receptor 1 adaptor protein, in TNFα-induced cell signaling and biological responses.

TNF-α is a pleiotropic cytokine involved in the regulation of various biological effects, including cell survival and proliferation, cell differentiation, and cell death. Moreover, TNF-α triggers proinflammatory responses, essentially through its ability to promote the expression of various proinflammatory genes. Most of the biological effects initiated by TNF-α rely on its ability to bind to and activate TNF-R1. As a consequence, molecular complexes are being formed, resulting from the recruitment of multiple adaptor proteins to the intracellular TNF-R1 DD. The adaptor protein FAN constitutively binds to a proximal membrane domain of TNF-R1 called NSD. Herein, the role of FAN in TNF-α-induced cell signaling and biological responses is discussed.
Reduced Ghrelin Secretion in the Hypothalamus of Rats due to Cisplatin-Induced Anorexia
Authors: Yakabi Koji , Sadakane Chiharu , Noguchi Masamichi , Ohno Shino , Ro Shoki , Chinen Katsuya , Aoyama Toru , Sakurada Tomoya , Takabayashi Hideaki , Hattori Tomohisa
Published: June 2010

Although chemotherapy with cisplatin is a widely used and effective cancer treatment, the undesirable gastrointestinal side effects associated with it, such as nausea, vomiting, and anorexia, markedly decrease patients’ quality of life. To elucidate the mechanism underlying chemotherapy-induced anorexia, focusing on the hypothalamic ghrelin secretion-anorexia association, we measured hypothalamic ghrelin secretion in fasted and cisplatin-treated rats. Hypothalamic ghrelin secretion changes after vagotomy or administration of cisplatin. Cisplatin + rikkunshito, a serotonin 2C receptor antagonist or serotonin 3 receptor antagonist, was investigated. The effects of intracerebroventricular (icv) administration of ghrelin or the serotonin 2C receptor antagonist SB242084 on food intake were also evaluated in cisplatin-treated rats. Hypothalamic ghrelin secretion significantly increased in 24-h-fasted rats compared to freely fed rats and was markedly reduced 24 and 48 h after cisplatin treatment in cisplatin-treated rats compared to saline-treated rats, although their plasma ghrelin levels were comparable. In cisplatin-treated rats, icv ghrelin administration reversed the decrease in food intake, vagotomy partially restored hypothalamic ghrelin secretion, and hypothalamic serotonin 2C receptor mRNA expression increased significantly. Administration of rikkunshito (an endogenous ghrelin enhancer) or a serotonin 2C receptor antagonist reversed the decrease in hypothalamic ghrelin secretion and food intake 24 h after cisplatin treatment. Cisplatin-induced anorexia is mediated through reduced hypothalamic ghrelin secretion. Cerebral serotonin 2C receptor activation partially induces decrease in hypothalamic ghrelin secretion, and rikkunshito suppresses cisplatin-induced anorexia by enhancing this secretion.
Cortisol Is Involved in Temperature-Dependent Sex Determination in the Japanese Flounder
Authors: Yamaguchi Toshiya , Yoshinaga Norifumi , Yazawa Takashi , Gen Koichiro , Kitano Takeshi
Published: June 2010

In vertebrates, sex is normally determined by genotype. However, in poikilothermal vertebrates, including reptiles, amphibians, and fishes, sex determination is greatly influenced by environmental factors, such as temperature. Little is known about the molecular mechanisms underlying environmental sex determination in these species. The Japanese flounder (Paralichthys olivaceus) is a teleost fish with an XX/XY sex determination system. However, XX flounder can be induced to develop into predominantly either phenotypic females or males, by rearing at 18 or 27 C, respectively, during the sex differentiation period. Therefore, the flounder provides an excellent model to study the molecular mechanisms underlying temperature-dependent sex determination. We previously showed that an aromatase inhibitor, an antiestrogen, and 27 C treatments cause masculinization of XX flounder, as well as suppression of mRNA expression of ovary-type aromatase (cyp19a1), a steroidogenic enzyme responsible for the conversion of androgens to estrogens in the gonads. Furthermore, estrogen administration completely inhibits masculinization by these treatments, suggesting suppression of cyp19a1 mRNA expression, and the resultant estrogen biosynthesis may trigger masculinization of the XX flounder induced by high water temperature. Here, we demonstrated that cortisol causes female-to-male sex reversal by directly suppressing cyp19a1 mRNA expression via interference with cAMP-mediated activation and that metyrapone (an inhibitor of cortisol synthesis) inhibits 27 C-induced masculinization of XX flounder. Moreover, cortisol concentrations in 27 C-reared juveniles were significantly higher than in 18 C-reared fishes during sexual differentiation. These results strongly suggest that masculinization by high water temperature is ascribable to elevation of cortisol concentration during gonadal sex differentiation in the flounder.
Hyperglycemia-Induced p66shc Inhibits Insulin-Like Growth Factor I-Dependent Cell Survival via Impairment of Src Kinase-Mediated Phosphoinositide-3 Kinase/AKT Activation in Vascular Smooth Muscle Cells
Authors: Xi Gang , Shen Xinchun , Radhakrishnan Yashwanth , Maile Laura , Clemmons David
Published: June 2010

Hyperglycemia has been shown to induce the p66shc expression leading to increased reactive oxygen species (ROS) generation and apoptosis. In the present study, we demonstrated that hyperglycemia induced p66shc expression in vascular smooth muscle cells. This induction was associated with an increase in apoptosis as assessed by the increase of capspase-3 enzymatic activity, cleaved caspase-3 protein, and the number of dead cells. The ability of IGF-I to inhibit apoptosis was also attenuated. Further studies showed that hyperglycemia-induced p66shc inhibited IGF-I-stimulated phosphoinositide (PI)-3 kinase and AKT activation. Mechanistic studies showed that knockdown of p66shc enhanced IGF-I-stimulated SHPS-1/p85, p85/SHP-2, and p85/Grb2 association, all of which are required for PI-3 kinase/AKT activation. These responses were attenuated by overexpression of p66shc. IGF-I-stimulated p85 and AKT recruitment to the cell membrane fraction was altered in the same manner. Disruption of p66shc-Src interaction using either a blocking peptide or by expressing a p66shc mutant that did not bind to Src rescued IGF-I-stimulated PI-3 kinase/AKT activation as well as IGF-I-dependent cell survival. Although the highest absolute level of ROS was detected in p66shc-overexpressing cells, the relative increase in ROS induced by hyperglycemia was independent of p66shc expression. Taken together, our data suggest that the increase in p66shc that occurs in response to hyperglycemia is functioning to inhibit IGF-I-stimulated signaling and that the incremental increase in SMC sensitivity to IGF-I stimulation that occurs in response to p66shc induction of ROS is not sufficient to overcome the inhibitory effect of p66shc on Src kinase activation.
When Parametric Sensitivity Analysis Isn't Enough
Authors: Caulkins Jonathan P.
Published: June 2010

This article addresses the issue of structural vs. parametric sensitivity analysis in three parts. The first part, intended for instructors, offers some conjectures about why structural sensitivity analysis is relatively neglected. It is intended to stimulate debate about the way sensitivity analysis is taught. The second gives an example from a real and interesting decision domain (drug legalization) in which structural uncertainty swamps parametric uncertainty. I have presented some variation of this example in a variety of graduate courses, both OR related and not, as well as to drug policy makers and researchers. I have not used it as a formal case but believe it could be taught in that format and two variants of the case questions are given in the third part. Elementary microeconomics would be a prerequisite to using the material in case format.
Using Digital Video Technology to Reduce Communication Apprehension in Business Education
Authors: Leeds Elke M. , Maurer Ruth A.
Published: June 2010

Several studies have shown that communication apprehension (CA) plays a significant role in reducing the effectiveness of oral communication in business settings. To compound this problem, environmental needs for large classes deny students the opportunity to present in the classroom and prevent universities from adequately addressing CA. In this study, digital video was used as a multimedia replacement for in-class oral presentations. A digital video treatment was designed and tested on a sample of second year management information systems (MIS) students at a large southeastern state university to determine its impact on CA. McCroskey's [McCroskey, J. C. 1982. An Introduction to Rhetorical Communication, 4th ed. Prentice-Hall, Englewood Cliffs, NJ] Personal Report of Communication Apprehension (PRCA-24) was used to measure CA in a pretreatment/posttreatment design. Results showed that the treatment is associated with a reduction in CA. A feedback survey indicated that participants in the treatment group spent more time on average practicing oral communication skills and most felt the treatment prepared them to present again. Digital video can benefit students through reduced CA, increased practice time, and the ability to review their presentation delivery. In a large class environment digital video may be used as an alternative to in-class presentation in order to benefit students who would otherwise not have the opportunity to present.
Process Simulation in Excel for a Quantitative Management Course
Authors: Hill Raymond R.
Published: June 2010

A nagging limitation of teaching spreadsheet-based quantitative decision-making courses is the sometimes stilted view of simulation presented, a view that overly emphasizes sampling simulation at the expense of process simulation. Without a viable spreadsheet-based process simulation package, the best efforts aimed at overcoming this emphasis on sampling simulation have provided passing references to special purpose simulation packages focused on process simulation. We introduce and discuss SimQuick as an alternative approach for teaching process simulation within the context of a spreadsheet-based approach to teaching simulation. Although an early tool, and somewhat limited when compared to special purpose simulation packages, SimQuick provides a viable means for teaching the process of simulation modeling and reinforcing the salient features of process modeling as a quantitative technique.
An Introduction to Queuing Theory in an Interactive Text Format
Authors: Ashley David W.
Published: June 2010

This paper presents an interactive tutorial on queuing that uses Microsoft Excel as a platform. The unique features of this tutorial are related to a pedagogical plan that is appropriate for students of business. Implementation of the features in Excel is also discussed.
Formulating Integer Linear Programs: A Rogues' Gallery
Authors: Brown Gerald G. , Dell Robert F.
Published: June 2010

“Convincing yourself is easy, persuading a colleague is harder, but proving it to a computer is hardest of all!”—R. Hamming, ca 1985.

The art of formulating linear and integer linear programs is, well, an art: It is hard to teach, and even harder to learn. To help demystify this art, we present a set of modeling building blocks that we call “formulettes.” Each formulette consists of a short verbal description that must be expressed in terms of variables and constraints in a linear or integer linear program. These formulettes can better be discussed and analyzed in isolation from the much more complicated models they comprise. Not all models can be built from the formulettes we present. Rather, these are chosen because they are the most frequent sources of mistakes. We also present Naval Postgraduate School (NPS) format; a define-before-use formulation guide we have followed for decades to express a complete formulation.
Lessons from Modeling Sudoku in Excel
Authors: Weiss Howard J. , Rasmussen Rasmus A.
Published: June 2010

In a previous paper, Chlond [Chlond, M. J. 2005. Classroom exercises in IP modeling: Sudoku and the log pile. INFORMS Trans. Ed. 5(2), http://ite.pubs.informs.org/Vol5No2/Chlond/ (last accessed on May 11, 2006)] presented the formulation of Sudoku as an integer program. Chlond claims that a spreadsheet formulation is not straightforward but we present a simple Excel formulation. In light of the current use of Excel in the classroom it can be highly instructive to formulate the problem using Excel. In addition, the formulation of this relatively simple model enables instructors to introduce students to the capability of programming Solver using VBA. In a follow-on paper (Rasmussen and Weiss [Rasmussen, R. A., H. J. Weiss. 2007. Advanced lessons on the craft of optimization modeling based on modeling sudoku in excel. INFORMS Trans. Ed. To appear]), we demonstrate advanced lessons that can be learned from using Premium Solver's powerful features to model Sudoku.
Influência do tipo de amostragem na constante dielétrica do solo e na calibração de sondas de TDR
Authors: Santos Marcelo Rocha dos , Zonta João Henrique , Martinez Mauro Aparecido
Published: June 2010

A técnica da TDR é uma importante ferramenta para o estudo do teor de água no solo. Para o correto emprego dessa técnica, é necessário calibrar modelos que relacionam o conteúdo volumétrico de água no solo com a constante dielétrica deste, considerando as características de cada solo. Assim, objetivou-se avaliar a influência do tipo de solo e da forma de amostragem (amostra deformada e não deformada) na constante dielétrica (Ka) do solo e no desempenho de modelos para a estimativa do conteúdo volumétrico de água no solo (), usando a técnica TDR. Os solos utilizados foram um Cambissolo Háplico Tb distrófico (CX), um Latossolo Vermelho ácrico típico (LV) e um Neossolo Quartzarênico (RQ), que apresentam diferenças quanto à textura. As amostras de solo referentes a CX e LV foram coletadas com estruturas deformadas e não deformadas, e as de RQ, apenas deformadas, devido à baixa agregação deste. A calibração foi realizada com sondas compostas de três hastes com 0,10 m de comprimento efetivo e 0,05 m de resina, com espaçamento entre hastes de 0,017 m e sem resistor na haste central, conectadas a um equipamento TDR 100 da Campbell Cientific. Os valores de Ka, para um mesmo valor de , foram alterados somente pela variação do tipo de solo, não sendo influenciados pelo tipo de amostragem do solo (deformada e não deformada). Em relação aos modelos testados para estimativa de em função de Ka, o polinomial cúbico foi o que apresentou melhor ajuste aos dados de determinados por gravimetria para o Neossolo Quartzarênico e para o Cambissolo Háplico, enquanto para o Latossolo Vermelho um modelo linear apresentou melhor ajuste.
Nutrient supply by mass flow and diffusion to maize plants in response to soil aggregate size and water potential
Authors: Oliveira Ermelinda Maria Mota , Ruiz Hugo Alberto , Alvarez V Víctor Hugo , Ferreira Paulo Afonso , Costa Fernanda Oliveira , Almeida Ivan Carlos Carreiro
Published: June 2010

Nutrients are basically transported to the roots by mass flow and diffusion. The aim of this study was to quantify the contribution of these two mechanisms to the acquisition of macronutrients (N, P, K, Ca, Mg, and S) and cationic micronutrients (Fe, Mn, Zn, and Cu) by maize plants as well as xylem exudate volume and composition in response to soil aggregate size and water availability. The experiment was conducted in a greenhouse with samples of an Oxisol, from under two management systems: a region of natural savanna-like vegetation (Cerradão, CER) and continuous maize under conventional management for over 30 years (CCM). The treatments were arranged in a factorial [2 x (1 + 2) x 2] design, with two management systems (CER and CCM), (1 + 2) soil sifted through a 4 mm sieve and two aggregate classes (< 0.5 mm and 0.5 - 4.0 mm) and two soil matric potentials (-40 and -10 kPa). These were evaluated in a randomized block design with four replications. The experiment was conducted for 70 days after sowing. The influence of soil aggregate size and water potential on the nutrient transport mechanisms was highest in soil samples with higher nutrient concentrations in solution, in the CER system; diffusion became more relevant when water availability was higher and in aggregates < 0.5 mm. The volume of xylem exudate collected from maize plants increased with the decrease in aggregate size and the increased availability of soil water in the CER system. The highest Ca and Mg concentrations in the xylem exudate of plants grown on samples from the CER system were related to the high concentrations of these nutrients in the soil solution of this management system.
Teores e características da matéria orgânica de solos hidromórficos do Espírito Santo
Authors: Nascimento Paulo César do , Lani João Luis , Mendonça Eduardo de Sá , Zoffoli Hugo José de Oliveira , Peixoto Henrique Theodoro Martins
Published: June 2010

Os teores e as características da matéria orgânica do solo (MOS) são resultados das taxas de produção e incorporação, decomposição ou alteração e mineralização, de acordo com as condições do ambiente. Nos solos hidromórficos, a dinâmica da MOS é influenciada pelo déficit de oxigênio, o que diminui a taxa de decomposição e gera produtos diferenciados em relação aos solos bem drenados. O presente trabalho teve por objetivo determinar os teores e características da matéria orgânica do solo em três diferentes localidades do Estado do Espírito Santo. Foram realizadas determinações de C orgânico total (COT) por três métodos, além de fracionamento das substâncias húmicas (SH), com determinação de teores das frações humina (FHU), ácidos húmicos (FAH) e ácidos fúlvicos (FAF), e determinações de matéria orgânica leve (MOL) e resíduos mínimos. Os resultados mostraram altos teores de C orgânico para a maioria dos horizontes superficiais dos perfis estudados, com ocorrência de material de constituição orgânica; altos valores na relação SH/COT e baixos valores para EA/FHU, indicando a fração humina como a predominante entre os compartimentos da MOS; maior mobilidade da fração ácidos fúlvicos, expressa por teores relativamente maiores em subsuperfície; e altos teores de MOL, indicando incipiente humificação, em razão do hidromorfismo.
Seleção de bactérias promotoras de crescimento no abacaxizeiro cultivar Vitória durante a aclimatização
Authors: Baldotto Lílian Estrela Borges , Baldotto Marihus Altoé , Olivares Fábio Lopes , Viana Alexandre Pio , Bressan-Smith Ricardo
Published: June 2010

A propagação in vitro do abacaxizeiro (Ananas comosus L. Merril) resulta na produção de uma grande quantidade de mudas sadias e homogêneas. Apesar dessas vantagens, a necessidade de um longo período de aclimatização onera essa prática agrícola. A aceleração do crescimento das plantas pela inoculação de bactérias diazotróficas endofíticas e epifíticas pode ser útil para diminuir esse período. O objetivo deste trabalho foi avaliar o potencial de 20 estirpes de bactérias diazotróficas em sintetizar indol, solubilizar fosfato de Ca e óxido de Zn e atuar antagonicamente ao fungo fitopatogênico Fusarium subglutinans f. sp. ananas, bem como, posteriormente, avaliar o desempenho do abacaxizeiro 'Vitória' propagado por cultura de tecidos em resposta à inoculação bacteriana durante o período de aclimatização em casa de vegetação. Foram medidas as características de crescimento da parte aérea e do sistema radicular e o conteúdo de nutrientes de folhas do abacaxizeiro. Os resultados mostraram diferenças na capacidade das bactérias de sintetizar indol, solubilizar fosfato de Ca e óxido de Zn e atuar antagonicamente ao Fusarium. Foram também constatadas diferenças na capacidade das bactérias em promover o crescimento da parte aérea e do sistema radicular e o acúmulo de N, P, K, Ca e Mg em folhas do abacaxizeiro. A inoculação das bactérias diazotróficas selecionadas pode promover o crescimento das mudas durante o período de aclimatização, melhorando a adaptação do abacaxizeiro ao ambiente ex vitro
Bermuda grass sod production as related to nitrogen rates
Authors: Lima Claudinei Paulo de , Backes Clarice , Villas Bôas Roberto Lyra , Oliveira Mauricio Roberto de , Kiihl Tammy Aparecida Manabe , Freitag Elisa Eni
Published: June 2010

Of all nutrients, N has the strongest effect on grass growth and an adequate N fertilization can reduce the time required for the formation of high-quality mats. This study aimed to evaluate the influence of N fertilization on Bermuda grass sod production and quality. The experiment was conducted in an area of commercial sod production, in Capela do Alto, state of São Paulo. Cynodon dactylon (Pers) L., known as Bermuda grass, was evaluated in a randomized complete block design with five treatments and four replications. Treatments consisted of five N rates: 0, 150, 300, 450 and 600 kg ha-1. Increasing N applications to Bermuda grass increased the soil cover rate, reducing the time required for mat formation. The accumulation of rhizome + root + stolon dry matter was highest at a rate of 354 kg ha-1 N and the mat resistance to breakage at a rate of 365 kg ha-1 N. Nitrogen rates between 354 and 365 kg ha-1 increased mat resistance and consequently the suitability for postharvest handling, tending to improve the efficiency in the area.
Soil-applied silicon decreases severity of wheat spot blotch on silicon-deficient soils
Authors: Zanão Júnior Luiz Antônio , Fontes Renildes Lúcio Ferreira , Coelho Paulo Henrique Moreira , Korndörfer Gaspar Henrique , Zambolim Laércio
Published: June 2010

Spot bloth caused by Bipolaris sorokiniana is an important wheat desease mainly in hot and humid regions. The aim of this study was to evaluate the response of wheat to different sources and modes of Si application, as related to the severity of wheat spot blotch and plant growth, in two Si-deficient Latosols (Oxisols). An greenhouse experiment was arranged in a 2 x 5 factorial completely randomized design, with eight replications. The treatments consisted of two soils (Yellow Latosol and Red Latosol) and five Si supply modes (no Si application; Si applied as calcium silicate and monosilicic acid to the soil; and Si applied as potassium silicate or monosilicic acid to wheat leaves). No significant differences were observed between the two soils. When Si was applied to the soil, regardless the Si source, the disease incubation period, the shoot dry matter yield and the Si content in leaves were greater. Additionally, the final spot blotch severity was lower and the area under the spot blotch disease progress curve and the leaf insertion angle in the plant were smaller. Results of Si foliar application were similar to those observed in the control plants.
Rugosidade da superfície do solo sob diferentes sistemas de manejo e influenciada por chuva artificial
Authors: Panachuki Elói , Bertol Ildegardis , Alves Sobrinho Teodorico , Vitorino Antônio Carlos Tadeu , Souza Cristiano Márcio Alves de , Urchei Mário Artemio
Published: June 2010

A rugosidade da superfície do solo é influenciada pelo manejo, formada em especial pelo tipo de preparo e reduzida pela ação da chuva, principalmente. O objetivo deste estudo foi avaliar a influência de diferentes sistemas de manejo do solo e da aplicação de chuva artificial na rugosidade da superfície do solo. Os tratamentos estudados resultaram da combinação de três sistemas de manejo do solo, semeadura direta (SD), preparo convencional (PC) e cultivo mínimo (CM), com três doses de resíduo vegetal seco de soja (Glycine max L. Merrill): 0, 2 e 4 Mg ha-1. Nas unidades experimentais foram aplicadas sete chuvas, com intensidade de precipitação pluvial de 60 mm h-1 e duração de 60 min cada, totalizando 420 mm de lâmina de chuva. A rugosidade foi avaliada imediatamente antes e após o preparo do solo e imediatamente após a aplicação de cada uma das sete chuvas artificiais. Obtiveram-se valores do índice de rugosidade ao acaso entre 1,88 e 5,41 mm na semeadura direta; entre 3,88 e 8,30 mm no preparo convencional; e entre 8,99 e 17,45 mm no cultivo mínimo. Concluiu-se que: as operações de preparo do solo aumentaram a rugosidade da sua superfície, em geral; o cultivo mínimo foi o sistema de preparo do solo que proporcionou os maiores valores de rugosidade ao acaso; e nos tratamentos semeadura direta com cobertura do solo a ação da chuva não promoveu decaimento do microrrelevo do solo.
Esterco de gado leiteiro associado à adubação mineral e sua influência na fertilidade de um latossolo sob plantio direto
Authors: Silva José Carlos Peixoto Modesto da , Motta Antônio Carlos Vargas , Pauletti Volnei , Veloso Cristina Mattos , Favaretto Nerilde , Barcellos Milena , Oliveira André Soares de , Silva Luiz Fernando Costa e
Published: June 2010

A produção de gado de leiteiro no sul do Brasil ocorre em grande parte em sistema de semi ou completo confinamento dos animais, o que gera uma produção significativa de resíduos. Os resíduos gerados vêm sendo utilizados como única fonte de nutrientes ou associados a fontes minerais na produção de grãos e silagem, mas sua influência nas características de solo não tem sido bem caracterizada. Este trabalho foi realizado com o objetivo de avaliar a influência de doses de adubação com esterco líquido de gado leiteiro, associadas com adubação mineral, sobre os níveis de P, K, C e condutividade elétrica (CE) de um Latossolo Bruno, em sistema plantio direto e rotação de culturas de inverno e verão (sorgo/aveia-preta/milho/azevém/milho/azevém), para produção de silagem, nas camadas de 0-5, 5-10, 10-30, 30-50 e 50-80 cm de profundidade. Os tratamentos foram distribuídos em três blocos casualizados, divididos em 12 parcelas cada bloco, em arranjo fatorial 3 x 4, sendo três níveis de adubação mineral (0, 50 e 100 % da dose recomendada para as culturas) e quatro níveis de adubação orgânica (0, 30, 60 e 90 m³ ha-1 ano-1). A adubação mineral proporcionou maiores valores de P disponível (Mehlich-1 e resina) até a profundidade de 10 cm, dada a adição em profundidade pela plantadeira, enquanto, com esterco aplicado em superfície, os maiores valores ficaram restritos à profundidade de 0-5 cm. Constatou-se esgotamento de K ao longo do perfil devido à elevada extração via silagem, tendo o esterco líquido aplicado uma relação linear com teor de K disponível, em todas as profundidades analisadas. A ausência de efeito da adubação mineral sobre o K deve-se, provavelmente, à baixa dose de K adicionada. Foi observada relação direta entre doses de esterco e teores de C orgânico na camada de 0-5 cm, o mesmo não sendo observado quando do uso de adubo mineral. Baixos valores de CE sugerem grande exportação de nutrientes pela produção de silagem. Os resultados obtidos indicam que não houve movimentação significativa de P no perfil do Latossolo, mesmo após seis anos sob altas doses de esterco de gado leiteiro, e que o K aplicado via esterco e adubação mineral não é suficiente para manter os níveis deste nutriente em sistemas em que a extração de K pela silagem é alta. Nessas situações, o aumento dos teores de C orgânico é restrito à camada superficial do solo em plantio direto e diretamente relacionado com a dose de esterco aplicada.