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The conquest of Mexico and the Aztecs by Hernan Cortes in 1521 is one of the classic chapters in any world history textbook. And, wow, what a classic turning point in history. One of the most power...

The Social Studies, with this issue, celebrates—if this is the correct word—the 500th anniversary of King Henry VIII of England's ascension to the throne. He was born in 1491, a year before Columbu...

Background: Myelofibrosis (MF) is recognized for its debilitating constitutional symptoms, splenomegaly, profound cytopenias and inflammatory state. Current MPN PROs (MF-SAF, MPN-SAF and MPN-10) have proven sensitive for symptom detection. Formal FDA qualification requires that these tools integrate a comprehensive literature search of previously reported symptoms as well as complete physician cognitive debriefing. Aims: In this investigation, we aimed to complete these required steps to ascertain the most prevalent and pertinent MPN symptoms for PRO inclusion. Methods: Literature Search: An initial review of the published literature was performed using OVID Medline®. The Medical Subject Headings (MeSH) terms included 'primary myelofibrosis' or 'MF', 'Myeloid metaplasia' and 'agnogenic myeloid metaplasia' which were meshed with 'symptom' or 'signs and symptoms' and limited from 1980 to 2011. Articles that were not original research or in the English language were excluded. Articles were then individually reviewed for content with further exclusion of case reports where search terms occurred concurrently with other medical conditions, articles presenting in-vitro data and articles with a primary focus on pharmacotherapy that utilized the MPN-SAF, MPN-SAF TSS or MF-SAF. Articles were then evaluated for all symptoms and recorded by the number of publications they were reported in. Cognitive Debriefing: International MPN specialists were contacted via email to complete the Physician Cognitive Debriefing Evaluation via a REDCAP® survey. Implied consent was provided through survey completion and demographic data was recorded. Responders were asked a series of questions on each symptom acquired through the literature search, along with three free-standing questions on MF PRO development. Thirteen responders were also contacted to complete an in-person interview and respond to eight questions on MF-PRO development. Descriptive statistics were used for data analysis. Results: The OVID Medline search yielded 166 articles for MF which were then individually reviewed. A total of 30 symptoms were extracted from the literature and recorded for incorporation into the REDCAP survey. The survey was distributed to 48 MPN specialists and 17 (35.4%) agreed to participate. Most responders were Caucasian (94.1%) and male (76.5%) with >5 years experience (94.1%) as physicians. Providers saw between 1-5 (58.8%), 6-10 (23.5%) or >10 (11.8) MF patients per week and most held primary practices in Europe (70.6%). Survey responses to symptom questions are provided in Figure 1. During in-person interviews, some providers felt that a different list of symptoms should be provided to patients with: early vs late MF (61.5%), primary vs secondary MF (7.7%) and clinical trial settings vs office environments (23.1%). Most providers felt that 'inactivity' (100%), 'fever' (92.3%) and 'weight loss' (92.3%) were signs as opposed to symptoms of the disease, though should still be included in the PRO (92.3% for each). Most providers believed that the ideal survey length should be between 10-20 questions. Two providers believed that 'health economics' and 'activities of daily living' should be integrated into a final PRO. Summary/Conclusions: Results of the literature search and Physician Cognitive Debriefing support that the MPN-SAF currently addresses the most frequent and symptomatic MF symptoms, with the exception of four items (dyspnea, easy bruising, arthralgias, nausea). Addition Patient Cognitive Debriefing is required to ensure that the final PRO is comprehensive of the most important symptoms to patients. (Figuer Presented).

The author presents five classroom activities that involve students in the settlement at Jamestown. Activity 1 simulates the problems encountered on the Godspeed, a fifty-two-foot foot boat with fifty-two passengers traveling across the Atlantic in 1607 for three slow months. In Activity 2, students plot their route, ocean currents, and wind affecting the speed of their 1607 boat crossing the Atlantic from London to Jamestown. In Activity 3, student teams analyze and try to solve problems encountered in the first year at Jamestown when over 70 percent of the adventurers died. In Activity 4, students participate in a skit describing the interesting relationship between Captain Smith and Pocahontas. In Activity 5, students compare and contrast information about Malinche, Pocahontas, and Sacajawea, three Native American women who played significant roles in the history of North America.

This article deals with the development of the expert system WIP (WIssensbasierte Prozessmodellierung = knowledge-based process modeling) for the configuration of process sequences in the field of process engineering.

(2008). How Can We Forget Rudolf II?: Book Review. The Social Studies: Vol. 99, No. 3, pp. 142-144.

Cf Article en Anglais dans Chemical Engineering & Technology, 1998, Vol 21 No 2, pp. 149-153

When working with disperse solid matter systems, one uses the effect of vibration in numerous processes. Solid matter mixing with vibration has only occurred in very simple units up to now. By means of the 3D-vibrational mixer from the company Kuston, Kleve, the influence of vibration on bulk materials and new mixing techniques are demonstrated. The 3D-vibrational mixer is suitable for liquids and solids, does not require mixing tools that need to be cleaned, and does not carry out rotary motions which would hinder incoming lines. It is used for mixing small amounts, where the mixing tank can be used simultaneously as the transportation container, so that a transfer is unnecessary. With the aid of 4 linear motors, the vibrational amplitudes and the frequencies can be varied within wide boundaries in all three spatial directions. By analyzing the vibrational system by means of Lissajous figures, it can be demonstrated that the optimal mixing effect occurs in the case of small frequency differences between the three axes. For freeflowing bulk materials, the best possible mixing state, the uniform coincidence mixing, is achieved after 2 min.

To investigate the transient processes by the mechanical foam destruction, a horizontal lamella is loaded with a falling drop. It is shown, that the drop can pass the lamella without destruction. The motion of the lamella is calculated numerically on the base of the describing differential equations, by considering the interia, surface tension and the Gibbs/Marangoni elasticity. The reduction of lamella thickness does not increase inevitably the rupture probability. A change between stable and unstable regions is found. The calculations show that high rupture probability occur when the minimum density of coverage has small values.

Mechanical design of agitation equipment requires information about the hydrodynamic stresses acting on impeller shafts, baffles, and vessels. In particular, vibrations induced in the generally freely supported impeller shafts impose very strong stresses on the shaft bearings at the natural frequency of the assembly and can lead to shaft fracture in extreme cases. Depending upon the speed of rotation, the surrounding medium acts as variable damping member owing to the differing flow conditions. This situation is examined in the present article.

For highly viscous products, multiple shaft agitators represent an interesting alternative to expensive special mixers. A triple shaft agitator with a volume of 250 liters is used to determine the powder consumption of the impellers and its relationship with the process parameters. The result shows that the power consumption of a single impeller running in multiple shaft mode is significantly smaller than of one running in single shaft mode. But the power required for the whole multiple shaft machine is much higher than that for a single shaft machine. A model is presented for detailed description of the interactions between the individual agitators in multiple shaft mode.

The purpose of this study was to investigate knee flexion torque and changes in electro myographic (EMG) activity of the medial and lateral hamstrings during isometric knee flexion at different angles. Thirty-four subjects, 17 female and 17 male, between 21 and 33 years of age, with no history of right knee pathology volunteered to participate. Subjects were positioned prone on the Cybex II with their right lower extremity secured in knee flexion. Surface electrodes were placed over the medial and lateral hamstring muscles. Each test session consisted of nine maximal isometric knee flexion contractions. Three contractions, of six seconds each, were recorded at 30, 60, and 90 degrees of knee flexion. Recordings of maximum torque and averaged EMG were made by the Cybex II and the Bioscope, respectively. The results showed statistically significant findings: (1) decreased torque as knee flexion increased (P < 0.0005); (2) men demonstrated greater torque than women (P < 0.05); and (3) EMG activity for both the medial and lateral hamstrings decreased as knee flexion increased with differences between 90 and 30°, and 90 and 60° (P < 0.05). We concluded that the decrease in torque output with increased knee flexion is consistent with present knowledge. The coordinated pattern of declining EMG activity with increased knee flexion for both the medial and lateral hamstring muscles requires further investigation. Copyright © 1996 Elsevier Science Ireland Ltd.

The influence of temperature and the extent of curing on the viscosity of a ,reactive epoxy resin adhesive is described and a mathematical model for the behavior is introduced. The temperature dependence of viscosity can be described by the WLF equation. The parameters required for the WLF equation are obtained from experiments in the temperature range where the crosslinking reaction has not yet been initiated. The viscosity and glass transition temperature increase with increasing curing. The glass transition temperature can also be described with an equation of the WLF type. Kinetic experiments on the epoxy resin adhesive enable a time and temperature dependent description of the extent of curing with a series reaction of the type A→B→C, where each partial reaction is of order n. The viscosity model and reaction kinetics enable calculation of the viscosity as a function of time and temperature, which agrees well with the experimental data.

Cross-flow filtration is a filtration process for separation of a disperse phase from liquids. Suspension flows tangentially to a membrane and the filtrate is drawn off perpendicular to the direction of flow. Formation of a filter cake on the membrane is thus prevented, reduced, or its composition modified. The principle of the separation is based on two opposing effects: on the one hand, the particles are transported by the filtration flux to the membrane where they cause an increase in concentration; on the other hand, concentration differences are again reduced by the turbulence of the cross-flow and by Brownian motion of the particles. The two mechanisms compete with each other and depend upon particle size in different ways. An energetic comparison of the two effects yields the separation law of cross-flow filtration as a steady state solution of the Fokker-Planck equation. The separation law has an exponential form and assigns each particle size a separation probability with which it reaches the membrane. Once on the membrane the particles may form a filter cake, flow through the pores or return to the bulk flow. If the particles remain on the membrane the ranges of layer-free and cake-forming filtration can be calculated from the hydrodynamic and geometric conditions of the cross-flow filter. Conventional cake filtration is regarded as limiting case. In continuous cross-flow filtration processes a low separation probability through the filtration pressure on selection of the filter medium resistance.

Foam and Foam Breaking – A Review. Many technical processes produce foams which complicate the performance of a given process or even make it possible. Foam breaking, therefore, becomes necessary. This paper outlines well known and new methods of foam breaking as well as the breaking principles. For the example of sprinkling, the influence of selected parameters on the destruction efficiency and the formation of secondary foam can be demonstrated. After a discussion the properties of foam, stabilizing and destabilizing effects, possibilities of foam characterization and foam avoidance are presented.

Background. Symptom burden in MPNs is severe and a risk factor for mortality in some disease subtypes (Blood 2010;115(9):1703-8). A recent trial comparing JAK2 treatment to best available therapy revealed that patients receiving conventional MPN therapies experienced no difference or worsening of symptoms (Blood 2011;118(21):a6501). No studies have evaluated the specific associations of conventional therapies on individual MPN symptoms using a validated patient-reported measure of symptom burden. Aims. We aimed to assess associations between conventional therapies on specific MPN symptoms using the MPN-SAF TSS (Blood 2011;118(21):a3839). Methods. Patient demographics, symptom burden and disease traits including therapies were collected from MPN patients and physicians at a single time point during therapy. MPN-SAF TSS included "worst"fatigue from the BFI and MPN-SAF items of concentration, early satiety, inactivity, night sweats, itching, bone pain, abdominal discomfort, weight loss and fever. MPN-SAF TSS was calculated as the total 10-item score, reported in a range of 0 to 100 for patients completing at least 6 of the 10 items. Results. Demographics: 1433 MPN patients were prospectively enrolled, including 594 essential thrombocythemia(ET), 538 polycythemia vera(PV) and 293 myelofibrosis(MF) patients from 11 countries. Of these, 1408 patients completed at least 6 of the 10 required items. Patients were 54% female with a median age of 63.Therapies: Common therapies included hydroxyurea/hydroxycarbamide(47.7%), salicylates(43.8%), interferon/pegylated- interferon(9.4%), and phlebotomies(5.3%) with 12.6% receiving no therapy. MPN-SAF TSS variations were observed between patients receiving and not receiving each therapy, although only one reached statistical significance (Table 1). Overall Treatment Effects: When comparing the overall effects of current therapy, worst fatigue was significantly more severe among PV patients undergoing treatment as compared to patients not receiving treatment (4.5(n=497) vs. 3.4(n=30), p=0.03). Among MF patients, abdominal comfort was significantly worse among patients not receiving therapy (3.3(n=57) vs. 2.3(n=230),p=0.02) .Aspirin: ET patients receiving aspirin reported significantly less weight loss than patients not receiving salicylates (0.62(n=298) vs. 0.98(n=283),p=0.03). Additionally, aspirin among ET patients reduced pruritus (1.5(n=296) vs. 2.0(n=284),p=0.02). PV patients receiving aspirin reported more concentration difficulties than patients on a non-aspirin regimen (3.0(n=254) vs. 2.4(n=264),p=0.01). MF patients receiving aspirin reported decreased bone pain (1.5(n=58) vs. 2.4(n=228),p=0.04) and abdominal discomfort (1.9(n=58) vs. 2.7(n=229),p=0.04). Hydroxyurea/hydroxycarbamide: PV patients receiving hydroxyurea/hydroxycarbamide reported decreased itching than patients not on this therapy, although this effect was of borderline significance (2.5(n=272) vs. 3.0(n=255),p=0.05). Phlebotomies: PV patients being given phlebotomies had significantly decreased problems with concentration compared to non-phlebotomized patients (1.9(n=71) vs. 2.8(n=447),p=0.02). Interferon/pegylatedinterferon: PV patients receiving interferon therapy reported increased early satiety (3.1(n=69) vs. 2.4(n=257),p=0.04), fever (0.7(n=67) vs. 0.3(n=455), p=0.02), and MPN-SAF TSS (25.5(n=69) vs. 21.2(n=460),p=0.04) than noninterferon- receiving counterparts. Conclusions. Few significant effects in overall symptom burden were observed in patients undergoing traditional MPN therapies. Though some effects reached nominal statistical significance, a portion may be spurious given the large number of tests performed. Further studies are needed to determine whether treatments impart additional symptom burden or if patients with specific symptom characteristics are selected to receive a particular treatment. Prospective serial assessment of conventional therapy impact is ongoing as part of a new clinical trial.

Background: In lymphoproliferative disorders serum β2-microglobulin (β2m) can be useful as a clinical marker. Material and Methods: β2m measurements were carried out with a new assay of Hoffmann-La Roche, which is a one-step solid-phase enzyme immunoassay with competitive inhibition. Sera of 81 healthy subjects, 42 patients with renal failure, 108 patients with monoclonal gammopathies [3 monoclonal gammopathies of undetermined significance (MGUS), 91 multiple myeloma (MM), 14 macroglobulinemia (MG)], and 11 patients with non-Hodgkin lymphoma (NHL) were tested. In addition β2m was determined during follow-up of 29 patients with myeloma and lymphoma. Results: β2m values of normal sera ranged from 1.0 to 3.0 mg/l in 97.5%. Patients with renal malfunction had the highest β2m concentrations (60 mg/l) with significant correlation (ρ 2m levels when compared to healthy controls. Serum β2m values did not correlate with the serum levels of monoclonal immunoglobulins. Using the myeloma staging system of Durie and Salmon, a strong association of pretreatment serum β2m with advanced stage of disease was found. In stages II and III, β2m levels were significantly higher than in stage I (p 2m concentrations within the normal range. No association with histologic cell types of myeloma was found. In the follow-up of patients with myeloma, β2m values decreased with response to chemotherapy and were low in stable remission. At relapse very high β2m concentrations were associated with a poor prognosis. Conclusion: Serum β2m appears to be a good prognostic marker in MM independent of the paraprotein concentration. In MM and also in other NHL, β2m determination helps to optimize therapy.

(1990). Review of Teaching for and Learning Social Studies Outcomes. The Social Studies: Vol. 81, No. 6, pp. 271-277.

Objectives To investigate the effect of a single low dose of mifepristone on ovarian function, when administered in the preovulatory period.Methods Healthy women with regular menstrual cycles were studied during two consecutive menstrual cycles. Either mifepristone or placebo was given in a randomized double-blind order when the leading follicle reached a diameter between 15 and 17 mm. Daily ultrasound and serum hormone measurements were obtained until follicular collapse. Statistical analysis was performed using Wilcoxon signed-rank test.Results Eight women entered the study, although one woman had to be excluded afterwards from analysis because her LH surge had already appeared on the day of treatment. The LH surge was delayed from day 14 to 17 (P = 0.01). Mifepristone caused a 3-day delay in follicular collapse, occurring on day 16 in control cycles and on day 19 in mifepristone treatment cycles (P = 0.02). The median cycle length was 26 days in control cycles and 30 days in mifepristone treatment cycles (P = 0.03). Progesterone measurement 7 days after follicular collapse did not differ significantly between both cycles.Conclusions A single 10-mg dose of mifepristone administered during the preovulatory phase of the cycle delays the LH surge and postpones ovulation.

(1995). The Image of Africa in Our Classrooms. The Social Studies: Vol. 86, No. 6, pp. 245-247.

The maintenance concepts adopted in South Africa are used to illustrate some of the strategies available to a telephone network operator in Africa. Attention is given to preventive vs. corrective maintenance and to maintenance staffing strategy. Maintenance aids and management of resources are also considered, with emphasis on tools and testers, manpower, maintenance instructions, training and replacement equipment.

How many major figures in history have been forgotten? We certainly want our children in school to know the full history of humankind, but how can they do this when so much of history has been forg...

A 15-year-old boy presented with a gunshot wound in the left cerebellar hemisphere. He was confused and left cerebellar signs were noted. The patient underwent the first surgery for debridement of the entry wound in the left parietal region and second surgery to remove the bullet. However, the bullet could not be located via a left unilateral suboccipital craniectomy in the park bench position, because it had migrated to the opposite side due to the effects of gravity in just a few hours. Skull radiography obtained just before the third surgery showed that the bullet had returned to the left side, and it was removed easily via the previous craniectomy in the sitting position. The clinical course suggests that in removing a bullet, skull radiography or computed tomography should be obtained just before surgery, or even intraoperatively, and that those findings should be the basis for the surgical procedure and operative position.

(1992). How Should We Teach about Columbus—as a Hero or a Villain? A Commentary on Hans Koning's Columbus: His Enterprise—Exploding the Myth. The Social Studies: Vol. 83, No. 1, pp. 27-29.

We studied the relevance of CEA, CA 19-9, CA 72-4 and the common classical prognostic factors (age, sex, tumor infiltration, N-classification, staging, grading and Lauren classification) in gastric carcinoma.Survival function estimates were calculated according the method to Kaplan-Meier. The patients were separated into two groups according to preoperative marker levels. Fixing specificity at 100% for healthy people, cut off levels were calculated. Survival curve differences were assessed using the log-rank-test. Multivariate Cox proportional hazards regression analysis was performed. The mantel-Haenszel method was used to assess the 2-year survival rate of patients with gastric carcinoma and high versus low levels of tumor-associated antigens adjusted to tumor stages. The study was performed on the frozen sera (stored at -80 degrees C) of 103 patients with histologically proven gastric carcinoma.The tumor stage (log-rank chi-square = 55.9; P0.0001) represents the best prognostic factor besides preoperative values of CA 19-9 (log-rank chi-square = 13.9; P0.001) and CEA (log-rank chi-square = 12.2; P0.001). CA 72.4 shows a log-rank chi-square of 6.9 (P0.01). We found no statistically significant correlation between survival and sex, tumor grade and Lauren classification. The importance of different parameters in providing additional prognostic information was evaluated by multivariate analysis. Only patients after curative surgical intervention (n = 55, R0) were considered. Cox proportional hazards regression analysis yielded an adjusted relative risk of 2.4 in patients with a preoperative CEA concentrationsor = 4 ng/mL vs.4 ng/mL, of 2.8 in patients with a preoperative CA 19-9 concentrationor = 60 U/mL vs.CA 19-9 and of 1.8 for stage III/IV vs. stage I/II (P0.05). For CEA the 2-year survival rates in the group of patients with preoperative serum concentrationsor = 4 ng/mL versus4 ng/mL and stadium III/IV were 14% versus 29% and in stadium I/II 50% versus 83% (P0.05). For CA 19-9 the 2-years survival rates in the group of patients with preoperative serum concentrationsor = 60 U/mL versus60 U/mL and stadium III/IV were 14% versus 28% and in stadium I/II 40% versus 83% (P0.05).The postoperative R-classification and the tumor stage represent the best prognostic information besides the preoperative values of CA 19-9 or CEA, respectively. The predictive information provided by preoperative CEA and CA 19-9 serum levels is additional to that obtained from other factors investigated.