Miracle-dz/UniFAR-FTUs huggingface dataset:
Dynamic behavior of the PV Grid-connected inverter based on L and LCL filter with active damping control

PV Grid-connected inverters must fulfill the standards specifications of current harmonics injected to the grid. In order to satisfy these grid requirements, passive filters are connected between the inverter and the grid. This paper compares the response characteristic of the traditional inductive (L) filter with the inductive-capacitive-inductive (LCL) filter. It is shown that the increasing the inductance L leads to a good ripple current suppression around the inverter switch frequency. The LCL filter provides better harmonic attenuation and reduces the filter size. The main drawback is the LCL filter impedance, which is characterized by a typical resonance peak, which has to be damped to avoid instability. Passive or active techniques can be used to damp the LCL resonance. To address this issue, this paper presents a comparison of passive and active damping strategies. Experimental results are given to support the theoretical analysis and to illustrate the performance of grid connected PV inverter system.
Automatic atlas-based segmentation of the breast in MRI for 3D breast volume computation.

PURPOSE Breast density is considered a significant risk factor and an important biomarker influencing the later risk of breast cancer. Prior breast segmentation is required when quantifying breast density with MRI in order to calculate the total breast volume and exclude nonbreast surrounding tissues. This paper describes an automatic 3D breast volume segmentation approach. METHODS The method is based on 3D local edge detection using phase congruency and Poisson surface reconstruction to extract the total breast volume. The boundary localization framework is integrated to a subsequent shape atlas-based segmentation using a Laplacian framework. RESULTS The 3D segmentation achieves breast-air and breast-chest wall boundary localization errors with a median of 1.36 mm and 2.68 mm, respectively, and an average volume error of 153.8 cm(3) when tested on 409 MRI datasets. Furthermore, the breast volume assessment technique will produce a 5.3% variability in the estimation of breast density in the tested population. CONCLUSIONS The fully automated segmentation approach of the breast in MRI allows the computation of total breast volume, a step required for breast density assessment. The use of features invariant to image intensity and a shape atlas to reinforce shape consistency are attractive characteristics of the method. Error analysis demonstrates that 5.3% variability in the estimation of breast density incurred by the method is an acceptable trade-off.
Exploring Conflicting Objectives with MADNS: Multiple Assessment Directed Novelty Search

Novelty search is an evolutionary approach which promotes phenotypic diversity in a population. Novelty search has been successfully applied to a wide range of domains and a number of variants have been proposed. Here we introduce Multiple Assessment Directed Novelty Search (MADNS), which exploits the notion that a diverse population optimised through phenotypic novelty may contain solutions to multiple conflicting objectives. We show that by utilising the MADNS algorithm, an evolutionary trajectory may be simultaneously directed towards conflicting objectives. We conclude that, through applying MADNS and MC-MADNS, a divergent evolutionary trajectory may be directed to provide simultaneous solutions to multiple conflicting problems in domains with large potential for exploration.
Crystal structure of Staphylococcus aureus Zn-glyoxalase I: new subfamily of glyoxalase I family

The crystal structures of protein SA0856 from Staphylococcus aureus in its apo-form and in complex with a Zn2+-ion have been presented. The 152 amino acid protein consists of two similar domains with α + β topology. In both crystalline state and in solution, the protein forms a dimer with monomers related by a twofold pseudo-symmetry rotation axis. A sequence homology search identified the protein as a member of the structural family Glyoxalase I. We have shown that the enzyme possesses glyoxalase I activity in the presence of Zn2+, Mg2+, Ni2+, and Co2+, in this order of preference. Sequence and structure comparisons revealed that human glyoxalase I should be assigned to a subfamily A, while S. aureus glyoxalase I represents a new subfamily B, which includes also proteins from other bacteria. Both subfamilies have a similar protein chain fold but rather diverse sequences. The active sites of human and staphylococcus glyoxalases I are also different: the former contains one Zn-ion per chain; the latter incorporates two of these ions. In the active site of SA0856, the first Zn-ion is well coordinated by His58, Glu60 from basic molecule and Glu40*, His44* from adjacent symmetry-related molecule. The second Zn3-ion is coordinated only by residue His143 from protein molecule and one acetate ion. We suggest that only single Zn1-ion plays the role of catalytic center. The newly found differences between the two subfamilies could guide the design of new drugs against S. aureus, an important pathogenic micro-organism.
Treatment-resistant Major Depressive Disorder with Psychotic Features is Associated with Impaired Processing Speed.

OBJECTIVE A proportion of patients with major depressive disorder (MDD) show cognitive impairment that is associated with treatment nonresponse and poorer functional recovery. A broader range of cognitive dysfunction has been found to be associated with treatment-resistant depression (TRD) and with the presence of psychotic symptoms. Thus far, the effects of psychotic symptoms on the neuropsychological profile of patients with treatment-resistant MDD have not been investigated. METHOD In the present study, 44 treatment-resistant MDD patients with (n = 12) or without (n = 32) psychotic symptoms-based on the Structured Clinical Interview (SCID I)-were compared with regard to their clinical status and performance in a neuropsychological test battery. The neuropsychological test battery assessed verbal skills, processing speed, executive functions and memory functions. RESULTS Patients with psychotic TRD displayed lower performance in processing speed than non-psychotic patients. The group differences were not associated with the severity or pervasiveness of depressive symptoms. The duration of depression (from the onset of depressive symptoms) was longer in the group of non-psychotic TRD patients, but no other group differences with respect to sociodemographic characteristics, age at the onset of symptoms or symptom severity were found. CONCLUSIONS The results imply that among individuals suffering from MDD, patients with the psychotic subtype who are unresponsive to standard pharmacological and psychosocial treatments have an increased vulnerability to cognitive dysfunction in the area of processing speed. Further research with larger sample size is warranted to determine whether these group differences persist after remission.
Matrix Metalloproteinase-13 (MMP-13) Directly and Indirectly Promotes Tumor Angiogenesis*

Background: Angiogenesis is an important step in the metastatic cascade of tumors. Results: MMP-13 itself as well as VEGF-A secretion from fibroblasts promotes angiogenesis. Indeed, MMP-13 is well correlated with blood vessel density in human cancer tissues. Conclusion: MMP-13 can be a marker for prediction of malignant behaviors and a therapeutic target in cancer. Significance: This work provides new insights regarding the role of MMP-13 in tumor angiogenesis. Matrix metalloproteinases (MMPs) are extracellular zinc-dependent endopeptidases involved in the degradation and remodeling of extracellular matrix in physiological and pathological processes. MMPs also have a role in cell proliferation, migration, differentiation, angiogenesis, and apoptosis. We previously identified cancer invasion-related factors by comparing the gene expression profiles between parent and the highly invasive clone of cancer cells. Matrix metalloproteinase-13 (MMP-13) was identified as a common up-regulated gene by cancer invasion-related factors. Although MMP-13 slightly promoted tumor invasion, we found that MMP-13 was involved in tumor angiogenesis. Conditioned medium from MMP-13-overexpressing cells promoted capillary formation of immortalized human umbilical vein endothelial cells. Furthermore, treatment with recombinant MMP-13 protein enhanced capillary tube formation both in vitro and in vivo. MMP-13-promoted capillary tube formation was mediated by activation of focal adhesion kinase and ERK. Interestingly, MMP-13 promoted the secretion of VEGF-A from fibroblasts and endothelial cells. By immunohistochemical analysis, we found a possible correlation between MMP-13 expression and the number of blood vessels in human cancer cases. In summary, these findings suggest that MMP-13 may directly and indirectly promote tumor angiogenesis.
Comparable increase of B-type natriuretic peptide and amino-terminal pro-B-type natriuretic peptide levels in patients with severe sepsis, septic shock, and acute heart failure*

Objective:B-type natriuretic peptide (BNP) and N-terminal pro-BNP measurements are used for the diagnosis of congestive heart failure (HF). However, the diagnostic value of these tests is unknown under septic conditions. We compared patients with severe sepsis or septic shock and patients with acute HF to unravel the influence of the underlying diagnosis on BNP and N-terminal pro-BNP levels. Design:Prospective, clinical study. Setting:Academic medical intensive care unit (ICU). Patients:A total of 249 consecutive patients were screened for the diagnosis of sepsis or HF. Sepsis was defined according to published guidelines. HF was diagnosed in the presence of an underlying heart disease and congestive HF, pulmonary edema, or cardiogenic shock. Interventions:BNP and N-terminal pro-BNP were measured from blood samples that were drawn daily for routine analysis. Measurements and Main Results:We identified 24 patients with severe sepsis or septic shock and 51 patients with acute HF. At admission, the median (range) BNP and N-terminal pro-BNP levels were 572 (13–1,300) and 6,526 (198–70,000) ng/L in patients with sepsis and 581 (6–1,300) and 4,300 (126–70,000) ng/L in patients with HF. The natriuretic peptide levels increased during the ICU stay, but the differences between the groups were not significant. Nine patients with sepsis and eight patients with HF were monitored with a pulmonary artery catheter. Mean (sd) pulmonary artery occlusion pressure were 16 (4.2) and 22 (5.3) mm Hg (p = .02), and cardiac indexes were 4.6 (2.8) and 2.2 (0.6) L/min/m2 (p = .03) in patients with sepsis and HF, respectively. Despite these clear hemodynamic differences BNP and N-terminal pro-BNP levels were not statistically different between the two groups. Conclusion:In patients with severe sepsis or septic shock, BNP and N-terminal pro-BNP values are highly elevated and, despite significant hemodynamic differences, comparable with those found in acute HF patients. It remains to be determined how elevations of natriuretic peptide levels are linked to inflammation and sepsis-associated myocardial dysfunction.
Life course determinants of insulin secretion and sensitivity at age 50 years: the Newcastle thousand families study

Suboptimal nutrition during fetal life and infancy is suggested to increase insulin resistance in adulthood. This study investigated the proportion of variance in insulin secretion and resistance accounted for by factors operating at different stages of life using a cohort of all 1142 births in the city of Newcastle, UK in May and June 1947.
Generation of an anti‐tumour immune response in a non‐immunogenic tumour: HSVtk killing in vivo stimulates a mononuclear cell infiltrate and a Th1‐like profile of intratumoural cytokine expression

Direct delivery of the herpes simplex virus thymidine kinase (HSVtk) gene, in combination with the prodrug ganciclovir (GC), has been used for the treatment of localised, inoperable tumours. Several groups have shown that when rodent tumours are ablated in vivo with suicide genes, antitumour immunity can also be generated. Hence, this approach may also be useful in treating disseminated disease. Here we have studied the mechanisms associated with this anti‐tumour immunity. In B16 HSVtk+ tumours being killed in vivo with GSC treatment, we observed the induction of a pronounced intratumoural infiltrate of macrophages, CD4+ and CD8+ T cells. In addition, using reverse transcriptase polymerase chain reaction, expression of interleukin (IL)‐2, IL‐12, interferon‐γ (IFN‐γ), tumor necrosis factor‐α (TNF‐α) and granulocyte/macrophage colony‐stimulating factor (GM‐CSF) but not IL‐4, IL‐6 or IL‐10, was observed, a profile of cytokine expression which resembles that of a Th1 immune response. To complement these findings, we also investigated the mechanisms by which expression of HSVtk leads to cell death. Our data show that B16/HSVtk+ cells die predominantly by necrosis, rather than apoptosis, on exposure to GC, a process which may be associated with the generation of anti‐tumour inflammatory responses. From these data we propose a model for the induction of anti‐tumour immunity using suicide genes and discuss the development of improved vectors for gene therapy to augment these effects in vivo. Int. J. Cancer 71:267–274, 1997. © 1997 Wiley‐Liss, Inc.
Development of standard reference materials for diagnosis of p53 mutations: Analysis by slab gel single strand conformation polymorphism

We have amplified by polymerase chain reaction (PCR) a 2.0 kbp region of the p53 gene containing exons 5–9 from seven cell lines reported in the literature to contain the majority of mutations reported for this gene. Sequence analysis of these products show that all seven cell lines contain mutations within the mutational hot spots of the p53 gene. Six of the seven clones have single base substitutions and the seventh has a single base delection. We have analyzed the seven p53 single point mutations by single strand conformation polymorphism (SSCP) analysis using fluorescence slab gel electrophoresis (SG‐SSCP). Fluorescent‐labeled PCR primers were used for amplification of specific exons for mutation detection. SG‐SSCP was conducted using Model 373 and Model 377 DNA sequencers with GeneScan Software (Perkin Elmer, Applied Biosystem Division). Nine different gel systems were first tested for their ability to resolve the p53 mutations using the Model 373 instrument. Two gel systems were capable of resolving all of the mutations that were screened. Optimal results were obtained with 12% w/v acrylamide 50:1 plus 10% v/v glycerol. This gel system was used to evaluate the effect of temperature on the ability to resolve the mutations. The separation with respect to wild type varied for each mutation examined. Subambient temperature (20°C) was preferable overall for discrimination of these mutations as a group. We intend to use this system to examine a much larger panel of p53 mutation standards that are now under development.
Effect of Dietary Putrescine on Whole Body Growth and Polyamine Metabolism

Abstract Putrescine (1,4-diaminobutane) is the simplest of the mammalian polyamines. These are small, positively charged molecules which are essential for cell growth and are thought to play a role in regulation of anabolic events such as synthesis of DNA, RNA, and protein. Recent reports have indicated the potential for dietary precursor amino acids of putrescine to alter tissue putrescine concentrations. The current study was conducted to determine the physiologic significance of these effects by feeding up to flooding doses of putrescine to determine any influence on whole body growth and polyamine metabolism. A total of 96 chicks were fed purified crystalline amino acid diets containing 0.0, 0.2, 0.4, 0.6, 0.8, or 1.0% purified putrescine (four birds per pen, four pens per diet) for 14 days. The feeding of 0.2% putrescine increased growth rate beyond that of controls while further supplements reduced growth and were toxic when 0.8 and 1.0% putrescine were fed. Hepatic and muscle concentrations of ornithine increased with dietary putrescine while the effect in kidney was much less. Putrescine concentrations in liver, kidney, and muscle rose when 0.4% putrescine or more was fed. This effect was particularly obvious in muscle in which there were also increases in the concentrations of spermidine and spermine. In a subsequent similar experiment, putrescine was fed at 0.0, 0.1, 0.2, 0.3, 0.4, or 0.5% to determine the effect on the activities of the key enzymes regulating polyamine synthesis. The feeding of putrescine at even 0.1% caused a rapid reduction in hepatic ornithine decarboxylase activity while S-adenosylmethionine decarboxylase and arginase activities were not influenced by diet. It was concluded that excess tissue putrescine can be toxic to whole organisms but small, orally administered doses of this metabolite can promote growth.
Molecular and serological assessment of parvovirus B19 infections among sickle cell anemia patients.

INTRODUCTION Parvovirus B19 is a cause of hemolysis and red blood cell aplasia in patients with sickle cell anemia. The present study aimed to assess parvovirus B19 infection among sickle cell anemia patients. METHODOLOGY All patients (n = 138) included in the study were sickle cell anemia patients. Blood donors were used as a control group. Assessment of parvovirus B19 antibodies and viral DNA was performed using established methods of detection and B19 recomBlot assay. RESULTS Detectable levels of parvovirus B19 IgG were found in 52 samples (37.6%) whereas anti-parvovirus B19 IgM antibodies were detected in four (2.89 %) patients of the sickle-cell anemia group. Anti-B19 IgM-positive samples contained B19-viral DNA. These four patients presented with fever, malaise, pallor and no cutaneous rash. Anti-parvovirus B19 antibodies were detected in 22 (39.3%) of the control blood donors group. Anti-parvovirus B19 IgM antibodies were not detected in the control group. Using the recomBlot assay, 58 test samples (42%) were found to contain detectable levels of Parvovirus B19 antibodies. All the samples that were positive for parvovirus B19 IgG by the ELISA were also positive by the recomBlot assay. Six samples were only positive by the recomBlot assay and not by the ELISA. Two of these six samples were positive for B19 viral DNA. CONCLUSIONS Establishing the extent of parvovirus B19 infection in sickle cell anemia patients will help in proper management of aplastic crisis in such patients. The B19 recomBlot assay may be suitable as a confirmatory assay.
Mot protein assembly into the bacterial flagellum: a model based on mutational analysis of the motB gene.

The 308 residue MotB protein anchors the stator complex of the Escherichia coli flagellar motor to the peptidoglycan of the cell wall. Together with MotA, it comprises the transmembrane channel that delivers protons to the motor. At the outset of the mutational analysis of MotB described here, we found that the non-motile phenotype of a DeltamotAB strain was rescued better by a pmotA(+)B(+) plasmid than the non-motile phenotype of a DeltamotB strain was rescued by a pmotB(+) plasmid. Transcription in each case was from the inducible tac promoter but relied on the native ribosome-binding site (RBS). This result confirms that translational coupling to motA is important for normal translation of the motB mRNA, since overproduction of MotA in trans did not improve complementation by pmotB. However, introduction of an optimized RBS into pmotB (to generate pmotB(o)) did. To dissect the function of the periplasmic domain of MotB, site-directed mutagenesis was used to replace Gln, Ser, and Tyr codons scattered throughout motB with amber (UAG) codons. Plasmid-borne motB(am) genes were introduced into sup(o), supE, and supF strains to see what motility defects were imposed by particular amber mutations and whether the defects could be suppressed by amber-suppressor tRNAs inserting the native or heterologous amino acids. Amber mutations at codon 268 or earlier in pmotB, and at codon 261 or earlier in pmotB(o) or pmotAB, eliminated motility. Thus, in agreement with the deletion analysis of motB by another laboratory, we conclude that the portion of MotB carboxyl-terminal to its peptidoglycan-binding motif (residues 161 to 264) is not essential. In strains containing supE or supF alleles, motility defects associated with motB(am) mutations were suppressed weakly, if at all, in pmotB. In contrast, motility defects conferred by most motB(am) mutations in pmotB(o) or pmotAB could be suppressed to a significant extent. However, the S18(am), Q100(am), Q112(am), Q124(am), Y201(am), and Y208(am) mutations were still suppressed extremely poorly. Full-length MotB was present at very low levels in suppressor strains containing the first four mutations, but Y201(am) and Y208(am) were suppressed efficiently at the translational level. We suggest that a translational pause by suppressor tRNAs reading UAG at these two positions may divert the nascent polypeptide into an alternative folding pathway that traps MotB in a non-functional conformation. We further propose that MotA and MotB form a stable pre-assembly complex in the membrane. In this complex, MotB exists in a form that cannot associate with peptidoglycan and blocks the proton-conducting channel. Opening of the channel and attachment to the cell wall may occur when the complex collides with a flagellar basal body and MotA makes specific contacts with the C ring and/or the MS ring.
Investor overreaction on the Johannesburg Stock Exchange

Extracted from text . Number 49 - Part 1 C Muller* Investor overreaction on the Johannesburg Stock Exchange 1. Introduction Turning historic share price time series into profits has long been the aim of technical financial alchemists. Discovering the silver bullet trading rule, or the optimal leading indicator, has been the elusive lure for those who believed that the stock markets were inefficient and that price information held the key to future price movements. Several investigations (for example Roberts, 1959 and Fama, 1965) have shown the major stock markets to be weak-form efficient markets, and the Johannesburg Stock Exchange (JSE) is no exception. However, .
Academic Integrity and Pastoral Care: Dealing with Unprofessional Conduct in Engineering Students

This paper reports on an approach to unprofessional conduct such as cheating or computer abuse by engineering students. Students who violate behaviour norms are interviewed, and given a chance to explain. The department's Academic Integrity Officer advises on a suitable penalty, and the offence is recorded in the department's Register of Unprofessional Conduct. More serious cases are taken to the University Discipline Committee. Pastoral care is used to pre-empt breaches of discipline. At-risk students are identified early in the course, by diagnostic testing. They are offered remedial, 'foundation' classes, with monitored attendance. Staff are encouraged to identify 'problem' students, who are interviewed and may be referred to specialist help. Initial results show that such interventions are successful in retaining students who would otherwise fail their courses. Instances of unprofessional conduct show a significant decline in the last three years.