925 research outputs found
Current Policies and Practices around Public High School Advanced Mathematics Course Taking
The present article is a national overview of current policies and practices around advanced mathematics course taking in public high schools. It begins with an explanation of the mathematics courses in public high schools. Importance of course taking in mathematics in general and advanced mathematics course taking in particular is highlighted. Then, academic excellence and educational equity concerns surrounding advanced mathematics course taking are discussed. A major part of the article is a detailed account of current policies and practices as they are related to excellence and/or equity in advanced mathematics course taking. Under this section, three topics are discussed: graduation requirements in mathematics, course offerings in advanced mathematics, and factors that make up the decision making mechanism for advanced mathematics course placements. Under the section on graduation requirements, three dimensions are examined: Carnegie units required, specific courses required, and high school exit exams. Based on a detailed and careful examination of these policies and practices, the article concludes with recommendations on how to enhance equity and excellence in advanced mathematics course taking
Setting Realistically High Academic Standards and Expectations
The present article is an overview of current academic expectations in the U.S. education system. It starts with a brief introduction highlighting the importance of expectations in education. Then, the current, undesirable situation of the U.S. education system is illustrated through international comparisons of student achievement and academic expectations followed by a discussion of how well schools in the U.S. prepare students for the future in the face of a highly competitive global workforce. The paper proceeds with its central argument, presenting evidence from all levels of the education ladder, that low expectations play a crucial role in the overall low student achievement. Given the pervasiveness of low expectations, the article concludes with original recommendations that will help create a pool of high but realistic academic standards and expectations for all levels and populations in the education system
Simulation studies of spectral subtraction based temperature compensation of FBG sensor for structural health monitoring based on principal component analysis
NAPO as a novel marker for apoptosis
Apoptosis or programmed cell death plays a pivotal role in embryonic development and maintenance of homeostasis. It is also involved in the etiology of pathophysiological conditions such as cancer, neurodegenerative, autoimmune, infectious, and heart diseases. Consequently, the study of apoptosis is now at center of both basic and clinical research applications. Therefore, sensitive and simple apoptosis detection techniques are required. Here we describe a monoclonal antibody–defined novel antigen, namely NAPO (negative in apoptosis), which is specifically lost during apoptosis. The anti-NAPO antibody recognizes two nuclear polypeptides of 60 and 70 kD. The antigen is maintained in quiescent and senescent cells, as well as in different phases of the cell cycle, including mitosis. Thus, immunodetection of NAPO antigen provides a specific, sensitive, and easy method for differential identification of apoptotic and nonapoptotic cells
Učinak eksrakta kore brucijskog bora (Pinus brutia) na čiste i mješovite kulture buražnih bakterija i arheja te na fermentacijske značajke buraga in vitro
The aim of the study was to investigate the effects of Pinus brutia bark extract, which is rich in polyphenolic compounds of tannins, on both pure and mixed continuous cultures of rumen bacteria and archaea, as well as on rumen fermentation characteristics in vitro. Antimicrobial susceptibility assay with pure cultures was carried out in an anaerobic chamber. Pinus brutia bark extract exhibited a potential inhibitor activity (P<0.05) against pure cultures of Ruminococcus flavefaciens, Eubacterium ruminantium, and Methanobacterium formicicum while a growth stimulatory effect (P<0.05) was observed for Ruminoccocus albus, Butyrivibrio fibrisolvens, and Streptococcus bovis. Pinus brutia bark extract only had a potential inhibitor effect (P<0.05) on R. albus at the highest dose (1200 μg/mL). Pinus brutia bark extract also stimulated (P<0.05) the growth of pure cultures of Fibrobacter succinogenes, while it did not affect Megasphaera elsdenii, except at the highest dose. The effects of two doses (75 and 375 mg/L) of P. brutia bark extract on in vitro mixed cultures and rumen fermentation parameters were determined by the rumen simulation technique (Rusitec). Supplementation with P. brutia bark extract led to a quadratic decrease (P<0.05) in the cell numbers of R. flavefaciens. Production of total and individual short chain fatty acids (SCFA), acetate to propionate ratio (C2/C3), total protozoa, ruminal pH, and dry matter digestibility (DMD) did not change in the presence of P. brutia bark extract. Supplementation with both doses of P. brutia bark extract decreased (P<0.05) the ammonia-N concentrations. Ammonia-N concentration was lowest in the high-supplemented group (P<0.05). As a conclusion, inhibitory effects of P. brutia bark extract on some species in the pure cultures were in the same direction as with mixed ruminal cultures, while stimulatory effects disappeared. The lack of inhibitory effects on protozoa and on a large number of Gram-positive rumen bacteria in the mixed cultures suggests that its mechanism of action is not exactly similar to antibiotics. Although P. brutia bark extract did not alter ruminal SCFA, it could have potential to improve ruminal protein utilization without depressing rumen microbial fermentation.Cilj ovog rada bio je istražiti učinak ekstrakta kore brucijskog bora (Pinus brutia), koji je bogat polifenolnim sastojcima tanina, na čiste i mješovite kulture buražnih bakterija i arheja kao i na in vitro fermentacijske značajke buraga. Proveden je test antimikrobne osjetljivosti s čistim kulturama u anaerobnim uvjetima. Ekstrakt kore brucijskog bora pokazao je potencijalnu inhibitornu aktivnost (P < 0,05) protiv čistih kultura bakterija Ruminococcus flavefaciens, Eubacterium ruminantium i Methanobacterium formicicum, a stimulacijski učinak na rast (P < 0,05) opažen je za bakterije Ruminoccocus albus, Butyrivibrio fibrisolvens i Streptococcus bovis. Ekstrakt kore brucijskog bora imao je potencijalan inhibitorni učinak (P < 0,05) na R. albus samo u najvećoj dozi (1200 μg/mL). Također je imao stimulacijski učinak (P < 0,05) na čiste kulture Fibrobacter succinogenes, a nije utjecao na Megasphaera elsdenii osim u najvećoj dozi. Učinak dviju doza (75 i 375 mg/L) ekstrakta kore brucijskog bora na in vitro mješovite culture i pokazatelje fermentacije u buragu određen je simulacijskom tehnikom (Rusitec). Dodatak ekstrakta kore brucijskog bora doveo je do kvadratnog smanjenja (P < 0,05) broja stanica R. flavefaciens. Nije bilo promjena u proizvodnji ukupnih i pojedinačnih kratkolančanih masnih kiselina (SCFA), omjeru acetata i propionata (C2/C3), ukupnom broju protozoa, buražnom pH i probavljivosti suhe tvari (DMD). Suplementacija objema dozama ekstrakta kore brucijskog bora smanjila je (P < 0,05) koncentracije amonijaka-N. Koncentracija amonijaka-N bila je najniža u skupini s najvećom dozom suplementa (P < 0,05). Zaključujemo da je inhibitorni učinak ekstrakta kore brucijskog bora na neke vrste u čistim kulturama bio jednak onomu u mješovitim buražnim kulturama, a nije bilo stimulacijskog efekta. Manjak inhibitornih učinaka na protozoe i na mnoge Gram-pozitivne buražne bakterije u mješovitim kulturama upućuje na to da njihov mehanizam djelovanja nije jednak onomu kod antibiotika. Premda ekstrakt kore brucijskog bora nije promijenio buražni SCFA, mogao bi poboljšati iskorištavanje proteina u buragu a da pritom ne suprimira mikrobnu fermentaciju
Predictive value of admission red cell distribution width-platelet ratio for no-reflow phenomenon in acute ST segment elevation myocardial infarction undergoing primary percutaneous coronary intervention
Background: The red cell distribution width–platelet ratio (RPR), a novel inflammatory marker is currently used to predict inflammation in chronic diseases. It may be associated with adverse outcomes among artery disease but its prognostic value in ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI) has not been fully investigated. There is no data regarding the association between RPR and in-hospital major adverse cardiovascular events (MACEs). This study evaluated the relations between pre-procedural RPR and the in-hospital and long-term outcomes in STEMI patients undergoing primary PCI.
Methods: This study included 580 STEMI patients (77% men, mean age: 59 ± 12 years). The patients were divided into two groups according to thrombolysis in myocardial infarction (TIMI) flow grades after primary PCI. No-reflow was defined as a post-PCI TIMI flow grade of 0, 1 or 2 (group 1). Angiographic success was defined as TIMI flow grade 3 (group 2).
Results: Whole blood cell count, neutrophil and lymphocyte percentages, red cell distribution width, platecrit, neutrophil–lymphocyte ratio (NLR) and RPR values were higher among patients with no-reflow. On multivariate analysis, pain to balloon time, multivessel disease, TIMI thrombus grade, tirofiban, aspirin, previous coronary artery disease, NLR, platecrit and RPR remained independent predictors of no-reflow after primary PCI. Patients in no-reflow group tended to be higher percent in-hospital MACE, including nonfatal myocardial infarction and cardiovascular mortality compared to the reflow patients.
Conclusions: Admission NLR, platecrit and RPR are independent correlates of no-reflow and in-hospital MACEs among patients with STEMI undergoing primary PCI.
3,3-Dimethyl-2-benzofuran-1(3H)-one
In the title compound, C10H10O2, all the non-H atoms except the methyl C atoms lie on a crystallographic mirror plane. In the crystal, C—H⋯O hydrogen bonds link the molecules into zigzag chains running parallel to [100]. Weak π–π stacking interactions between the benzene rings [centroid–centroid distance = 3.9817 (5) Å] link the chains in the [010] direction
The first clinical case due to AP92 like strain of Crimean-Congo Hemorrhagic Fever virus and a field survey
<p>Abstract</p> <p>Background</p> <p>Crimean-Congo Hemorrhagic Fever (CCHF) is a fatal infection, but no clinical case due to AP92 strain was reported. We described the first clinical case due to AP92 like CCHFV.</p> <p>Methods</p> <p>A case infected by a AP92 like CCHFV was detected in Balkanian part of Turkey. Diagnosis was confirmed by RT-PCR and sequencing. A human serologic and tick survey studies were performed in the region, where the case detected.</p> <p>Results</p> <p>Thirty eight individuals out of 741 were found to be anti CCHFV IgM positive. The attack rate for overall CCHFV was calculated as 5.2%. In univariate analyses, CCHFV IgM positivity was found to be associated with the age (p < 0.001), male gender (p = 0.001), agricultural activity (p = 0.036), and history of tick bite (p = 0.014). In multivariate analysis, older age (OR: 1.03, CI:1.01–1.05, p < 0.001), male gender were found to be the risk factors (OR: 2.5, CI:1.15–5.63, p = 0.020) for CCHFV infection.</p> <p>Conclusion</p> <p>This is the first human case with AP92 like CCHFV infection. Furthermore, this is the first report of AP92 like strain in Turkey. In the region, elderly males carry the highest risk for CCHFV infection.</p
Imported Crimean-Congo hemorrhagic fever cases in Istanbul
We described a series of imported cases of Crimean-Congo Hemorrhagic Fever (CCHF) in Istanbul and investigated the genetic diversity of the virus. All the suspected cases of CCHF, who were applied to the health centers in Istanbul, were screened for CCHF virus (CCHFv) infection by using semi-nested Polymerase Chain Reaction (PCR) following RT-PCR. Simultaneous blood samples were also sent to the national reference laboratory in Ankara for serologic investigation. In 10 out of 91 patients, CCHFv was detected by PCR, and among 9 out of 10, anti-CCHFv IgM antibodies were also positive. Clinical features were characterized by fever, myalgia, and hemorrhage. The levels of liver enzymes, creatinine phosphokinase, and lactate dehydrogenase were elevated, and bleeding markers were prolonged. All the cases were treated with ribavirin. There was no fatal case. All the strains clustered within the same group as other Europe/Turkey isolates
The Ability to Generate Senescent Progeny as a Mechanism Underlying Breast Cancer Cell Heterogeneity
Background Breast cancer is a remarkably heterogeneous disease. Luminal, basal-like, "normal-like", and ERBB2+ subgroups were identified and were shown to have different prognoses. The mechanisms underlying this heterogeneity are poorly understood. In our study, we explored the role of cellular differentiation and senescence as a potential cause of heterogeneity. Methodology/Principal Findings A panel of breast cancer cell lines, isogenic clones, and breast tumors were used. Based on their ability to generate senescent progeny under low-density clonogenic conditions, we classified breast cancer cell lines as senescent cell progenitor (SCP) and immortal cell progenitor (ICP) subtypes. All SCP cell lines expressed estrogen receptor (ER). Loss of ER expression combined with the accumulation of p21Cip1 correlated with senescence in these cell lines. p21Cip1 knockdown, estrogen-mediated ER activation or ectopic ER overexpression protected cells against senescence. In contrast, tamoxifen triggered a robust senescence response. As ER expression has been linked to luminal differentiation, we compared the differentiation status of SCP and ICP cell lines using stem/progenitor, luminal, and myoepithelial markers. The SCP cells produced CD24+ or ER+ luminal-like and ASMA+ myoepithelial-like progeny, in addition to CD44+ stem/progenitor-like cells. In contrast, ICP cell lines acted as differentiation-defective stem/progenitor cells. Some ICP cell lines generated only CD44+/CD24-/ER-/ASMA- progenitor/stem-like cells, and others also produced CD24+/ER- luminal-like, but not ASMA+ myoepithelial-like cells. Furthermore, gene expression profiles clustered SCP cell lines with luminal A and "normal-like" tumors, and ICP cell lines with luminal B and basal-like tumors. The ICP cells displayed higher tumorigenicity in immunodeficient mice. Conclusions/Significance Luminal A and "normal-like" breast cancer cell lines were able to generate luminal-like and myoepithelial-like progeny undergoing senescence arrest. In contrast, luminal B/basal-like cell lines acted as stem/progenitor cells with defective differentiation capacities. Our findings suggest that the malignancy of breast tumors is directly correlated with stem/progenitor phenotypes and poor differentiation potential. © 2010 Mumcuoglu et al
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