The predominant SW aspect of the enigmatic dragonblood tree under

The predominant SW aspect of the enigmatic dragonblood tree underlines the importance of fog. Long-term weather observations by Socotri put these short-term meteorological observations into a longer perspective. Socotri informants also described the 3-MA purchase drought years when livestock populations crashed, after which windows of opportunities for the regeneration of dragonblood and other grazing-sensitive trees may have occurred. (C) 2010 Elsevier Ltd. All rights reserved.”
“In the current health care climate, economic and cultural conditions have created an

optimal opportunity to envision a new direction for nursing as a profession. Nurses find themselves at the formative stages of charting this new direction. The articulation of a professional practice model provides a framework for setting this new direction and thus the achievement of exemplary clinical outcomes. In this article, the authors describe the evolution of the professional

LY2606368 nmr practice model at the Massachusetts General Hospital and how the model continues to be evaluated and modified over time by the nurses within the system.”
“Epilepsy remains a major medical problem for which there is no effective treatment. Oxidative damage plays an important role in epilepsy pathogenesis and may represent a target for treatment of epilepsy. Recent studies have suggested that nuclear factor LY3023414 chemical structure erythroid 2-related factor 2 (Nrf2) binds to antioxidant response element (ARE) to induce antioxidant and phase II detoxification enzymes under conditions of oxidative stress, which reduces oxidative damage and accumulation of toxic metabolites. This study evaluated the role of Nrf2-ARE signal pathway in protecting the brain from seizure-mediated damage. Wistar rats and Nrf2-deficient or control mice were chronic kindled in the amygdala. Sulforaphane (SF) was used to activate Nrf2-ARE signal pathway. The progression of kindling, the cognitive impairment and oxidative stress parameters were assessed to determine the extent of seizure-mediated

brain damage. Our results indicate that activation Nrf2-ARE signal pathway with SF in hippocampus suppressed the progression of amygdala kindling, and also ameliorated the cognitive impairment and oxidative stress induced by epileptic seizure. These observations suggest that Nrf2-ARE signal pathway may represent a strategic target for epilepsy therapies. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.”
“Background: Surrogate decision makers (SDMs) face difficult decisions at end of life (EOL) for decisionally incapacitated intensive care unit (ICU) patients. Purpose: To identify and describe the underlying psychological processes of surrogate decision making for adults at EOL in the ICU. Methods: Qualitative case study design using a cognitive task analysis interviewing approach.

33%); and Streptomyces spp (36 20%) Depths

of collectio

33%); and Streptomyces spp. (36.20%). Depths

of collection of sediment samples does not appear to affect the distribution of the actinomycetes genera, but choice of media appears to be a contributing factor to consider in cultivating marine actinomycetes as the M1 agar appears to support actinomycetes growth than CSPY-ME agar. We conclude that Algoa Bay sediment promises to be an important reservoir of marine actinomycetes of potentially biotechnological relevance.”
“This study aimed to analyze seasonal variations in the antioxidant defence systems of Torin 2 cell line the seminal plasma and fluids of the cauda epididymis and vesicular glands of the boar. The analyzed antioxidants included superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and total L-glutathione (GSH+GSSG). Seasonal changes in total protein content and total antioxidant status

(TAS) of the seminal plasma and reproductive fluids were also analyzed. RG-7388 concentration Compared with the spring-summer period, total protein content in the seminal plasma was significantly higher during the autumn-winter period. Among the antioxidants analyzed, only SOD activity showed marked seasonal variations, being significantly higher during the spring-summer period. Likewise, the fluid of the cauda epididymis exhibited greater SOD and CAT activity during the spring-summer period, whereas TAS levels were markedly higher during the autumn-winter period. Neither GPx activity nor total GSH+GSSG content in the cauda epididymal fluid was significantly affected by the seasonal periods. The vesicular gland fluid exhibited an approximately 4-fold greater level of SOD activity during the autumn-winter period, as compared with the spring-summer period. By contrast, greater CAT and GPx activity, and a higher level of total GSH+GSSG were observed in the vesicular gland fluid during the spring-summer

period. In conclusion, the findings of this study indicate that seasonal variations could have varying effects on the antioxidant defence systems in the seminal plasma and fluids of the boar reproductive tract. Reproductive Biology 2011 11 1: 37-47.”
“Several benign, premalignant, and malignant lesions may arise on the vulva, and multiple types of procedures may be used to diagnose and treat these conditions. Punch and shave biopsies may be used to diagnose most vulvar conditions, but lesions suspected of being melanomas may best be diagnosed with narrow-margin excisional biopsies. Bartholin gland cysts and abscesses may be treated with several different treatment modalities, the most common of which are fistulization and marsupialization. Genital warts may be treated with several medical and surgical modalities to relieve symptoms.”
“Enzymes acting on beta-linked arabinofuranosides have been unknown until recently, in spite of wide distribution of beta-L-arabinofuranosyl oligosaccharides in plant cells.

05) Aconitate hydratase 2 (ACO2), which catalyzes the conversion

05). Aconitate hydratase 2 (ACO2), which catalyzes the conversion of citrate to isocitrate in TCA cycle, was down-regulated in animals of the high-fat group (p smaller than 0.05). Inflammatory markers annexin A3 (ANXA3) and annexin A5 (ANXA5) were up-regulated by the high-fat diet (p smaller than 0.05). Moreover, enzymes involved in the urea cycle were suppressed by high-fat diet, including carbamoyl phosphate synthase 1 (CPS1), ornithine transcarbamoylase (OTC), argininosuccinate synthase (ASS), argininosuccinate lyase (ASL), and arginase 1 (ARG 1). Post-translational modifications

(PTM) of ANXA3, ANXA5, and XDH were also analyzed. A set of differentially expressed proteins were identified as molecular markers Volasertib concentration for elucidating the pathological mechanism

of high-fat diet.”
“Background & Aims: Induced pluripotent stem click here (iPS) cells exert phenotypic and functional characteristics of embryonic stem cells even though the gene expression pattern is not completely identical. Therefore, it is important to develop procedures which are specifically oriented to induce iPS cell differentiation.\n\nMethods: In this study, we describe the differentiation of mouse iPS cells to hepatocyte-like cells, following a directed differentiation procedure that mimics embryonic and fetal liver development. The sequential differentiation was monitored by real-time PCR, immunostaining, and functional assays.\n\nResults: By sequential stimulation with cytokines known to play a role in liver Smoothened Agonist manufacturer development, iPS cells were specified to primitive streak/mesendoderm/definitive endoderm. They were then differentiated into two types of cells: those with hepatoblast features and those with hepatocyte characteristics. Differentiated hepatocyte-like cells showed functional properties of hepatocytes, such as albumin secretion, glycogen storage, urea production, and inducible cytochrome activity. Aside from hepatocyte-like cells, mesodermal cells displaying some characteristics of liver sinusoidal

endothelium and stellate cells were also detected.\n\nConclusions: These data demonstrate that a protocol, modeled on embryonic liver development, can induce hepatic differentiation of mouse iPS cells, generating a population of cells with mature hepatic phenotype. (C) 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.”
“No effective vaccine has been developed against the subgroup J avian leukosis virus (ALV-J). The genetic diversity of ALV-J might be related to the env gene, therefore, we selected conserved sequences of the env gene and designed interference sequence. In this study, microRNAs (miRNAs) were designed and synthesized, corresponding to conserved regions of the env gene. These miRNAs were cloned into the linearized eukaryotic expression vector. The recombinant plasmids were transfected into DF-1 cells. After transfection, the cells were inoculated with ALV-J.

We conclude that enkephalin elevations may contribute to cognitiv

We conclude that enkephalin elevations may contribute to cognitive impairments in hAPP mice and possibly in humans with AD. The therapeutic potential of reducing enkephalin production or signaling merits further exploration.”
“A series of substituted (benzamidostyryl) benzimidazole (3a-r) were synthesized and evaluated for their possible anti-inflammatory and ulcerogenicity. The structures of the synthesized compounds were confirmed on the basis of their spectral

data and elemental analysis. Majority of the compounds were active in carrageenan-induced hind paw edema method test and compounds 3b, 3k had shown high potency after 3 and 4 h time intervals (P < 0.001) almost equipotent to the standard drug indomethacin and showed less severity index than it.”
“Stimulating lymphocytes with

Ifn-gamma, anti-CD3, and interleukin-2 Acalabrutinib promotes the proliferation of a cell population coexpressing T-lymphocyte surface antigens such as CD3, CD8a, and CD25 as well as natural killer cell markers such as NK1.1, CD49, and CD69. These cells, referred to as cytokine-induced killer cells (CIKs), display cytotoxic activity against tumour cells, even without prior antigen presentation, and offer a new cell-based approach to the treatment of malignant diseases. Because CIKs are limited in vivo, strategies to optimize in vitro culture yield are required. In the last 10 years, mesenchymal stem cells (MSCs) have gathered considerable attention. Aside from their uses in tissue engineering and as support in haematopoietic stem cell transplantations,

MSCs show notable immunomodulatory characteristics, providing further possibilities for therapeutic applications. In this study, we investigated the influence of murine MSCs on proliferation, phenotype, vitality, and cytotoxicity of murine CIKs in a coculture system. We found that CIKs in coculture proliferated within 7 days, with an average growth factor of 18.84, whereas controls grew with an average factor of 3.7 in the same period. Furthermore, higher vitality was noted in cocultured Belnacasan inhibitor CIKs than in controls. Cell phenotype was unaffected by coculture with MSCs and, notably, coculture did not impact cytotoxicity against the tumour cells analysed. The findings suggest that cell-cell contact is primarily responsible for these effects. Humoral interactions play only a minor role. Furthermore, no phenotypical MSCs were detected after coculture for 4 h, suggesting the occurrence of immune reactions between CIKs and MSCs. Further investigations with DiD-labelled MSCs revealed that the observed disappearance of MSCs appears not to be due to differentiation processes.”
“Objective: To evaluate the association between mucin 2 (MUC2) expression and clinicopathological characters of colorectal cancer.\n\nMethods: A literature search was performed on December 31, 2010 according to defined selection criteria.

Third primer TdDHN16 (T durum L ) has shown entirely different P

Third primer TdDHN16 (T. durum L.) has shown entirely different PCR amplification prototype, specially showing two strong DNA bands while fourth primer RAB16C (O. saliva L.) failed to amplify buy PU-H71 DHN gene in any of the cultivars. Examination of DNA sequences revealed several interesting features. First, it identified the two exon/one intron structure of this gene (complete sequences were not shown), a feature not previously described in the two database cDNA sequences available from T. aestivum L. (gi vertical bar 21850). Secondly, the analysis identified several single nucleotide polymorphisms (SNPs), positions in gene sequence. Although complete gene sequence was not obtained for all

the cultivars, yet there were a total of 38 variable positions in exonic (coding region) sequence, from a total gene length of 453 nucleotides. Matrix of SNP shows these 37 positions with individual sequence at positions given for each of the 14 cultivars (sequence of two cultivars was not obtained) included in this analysis. It demonstrated a considerable diversity for this gene with only three cultivars i.e. TJ-83, Marvi and TD-1 being similar to the selleck chemicals llc consensus

sequence. All other cultivars showed a unique combination of SNPs. In order to prove a functional link between these polymorphisms and drought tolerance in wheat, it would be necessary to conduct a more detailed study involving directed mutation of this gene and DHN gene expression.”
“Resistance to isoniazid, ethambutol, and streptomycin was

detected in a Mycobacterium tuberculosis strain, belonging to the Beijing family lineage, isolated from two nodule exudates of a Yorkshire terrier with generalized tuberculosis. This report alerts medical practitioners to the risk of dissemination of pre-multidrug-resistant tuberculosis (preMDR-TB) through exposure to M. tuberculosis-shedding pets.”
“Purpose: This study aimed to assess the impact of transoral incisionless fundoplication (TIF) on patients with chronic gastroesophageal reflux disease (GERD) at 12-month follow-up. Methods: Clinical outcomes of 100 consecutive patients check details with chronic GERD who underwent TIF between January 2010 and February 2011 were analyzed. Results: There were no major complications reported. Esophageal acid exposure was normalized in 14/27 (52%) of patients who underwent 12-month pH testing. Seventy-four percent of all patients were off proton pump inhibitors versus 92% on daily proton pump inhibitors before TIF, P smaller than 0.001. Daily bothersome heartburn and regurgitation symptoms were eliminated in 66/85 (78%) and 48/58 (83%) of patients. Median reflux symptom index score was reduced from 20 (0 to 41) to 5 (0 to 44), P smaller than 0.001. Two patients reported de novo dysphagia and 1 patient reported bloating (scores 0 to 3). Six patients underwent revision; 5 laparoscopic Nissen fundoplication and 1 TIF.

The quenching of T526GST intrinsic fluorescence allowed for the d

The quenching of T526GST intrinsic fluorescence allowed for the determination of the dissociation constants (K-D) for all ligands. Obtained data indicate that T526GST binds to all ligands but with different affinity. Porphyrins and lipid peroxide products inhibited T526GST catalytic activity up to 100% in contrast with only 20-30% inhibition observed for bile acids and two saturated fatty acids. Non-competitive type inhibition was observed for all enzyme inhibitor ligands except for transtrans-2,4-decadienal, which exhibited uncompetitive type inhibition. The dissociation constant value K-D = 0.7 mu M A for the hematin ligand, determined

Bafilomycin A1 in vitro by competitive fluorescence assays with ANS, was in good agreement with its inhibition kinetic value Ki 0.3 mu M and its intrinsic fluorescence quenching K-D = 0.7 mu M. The remaining ligands did not displace ANS from the enzyme suggesting the existence of different binding sites. In addition to the catalytic

activity of Ts26GST the results obtained suggest that the enzyme exhibits a ligandin function with broad specificity towards nonsubstrate ligands. (C) 2014 Elsevier Inc. All rights reserved.”
“Protein-protein interactions defined by affinity purification and mass spectrometry (APMS) suffer from high false discovery rates. Consequently, lists of potential interactions must be pruned of contaminants before network construction and interpretation, historically an expensive, time-intensive, and error-prone

task. In recent ICG-001 years, numerous computational methods were developed to identify genuine interactions from the hundreds of candidates. Here, comparative analysis of three popular algorithms, click here HGSCore, CompPASS, and SAINT, revealed complementarity in their classification accuracies, which is supported by their divergent scoring strategies. We improved each algorithm by an average area under a receiver operating characteristics curve increase of 16% by integrating a variety of indirect data known to correlate with established protein-protein interactions, including mRNA coexpression, gene ontologies, domain-domain binding affinities, and homologous protein interactions. Each APMS scoring approach was incorporated into a separate logistic regression model along with the indirect features; the resulting three classifiers demonstrate improved performance on five diverse APMS data sets. To facilitate APMS data scoring within the scientific community, we created Spotlite, a user-friendly and fast web application. Within Spotlite, data can be scored with the augmented classifiers, annotated, and visualized (

In 158 (12) procedures, cryomapping (38 cases) or cryoablation (1

In 158 (12) procedures, cryomapping (38 cases) or cryoablation (120 cases) were stopped due to transient AV block (first-degree AV block 74 cases, second-degree AV block 67 cases, and third-degree AV block 17 cases) after which another site was tested. Transient AV block occurred within seconds of mapping up to 3 min of ablation. The incidence of AV block was similar for different substrates. In most cases, AV nodal conduction was restored within seconds but in two cases transient AV block lasted

21 and 45 min, respectively. There were no cases of acute permanent AV blocks. No late AV blocks occurred during follow-up (mean 24 months, range 696 months).\n\nCryoablation adjacent to the AV node carries a negligible risk PF-04929113 concentration of permanent AV block. Transient AV block during ablation is a benign finding.”
“Thickness dependent Pendellosung oscillations are highly sensitive to strain fields from defects in a host crystal. Based on this, we present a novel technique to measure the precipitation kinetics of oxygen in silicon already

at its early stage of clustering at high temperatures. At 900 degrees C, precipitates with a radius smaller than 4 nm and with a density of 1 +/- 0.5 x 10(13) 1/cm(3) were observed. The technique was calibrated by complementary scanning transmission electron microscope and energy dispersive X-ray measurements in the range of normal diffusivity yielding a diffusion constant of 1.7 +/- 0.1 x 10(-12)cm(2)/s, which is close to the literature value of 2.074 x 10(-12)cm(2)/s. The measurements

have been made with the characteristic AZD5582 ic50 K-alpha 1-line of a high voltage tungsten X-ray tube at 59.31 keV, which provides the opportunity to illuminate through complex sample environments like high temperature scattering furnaces. (C) 2013 American Institute of Physics. []“
“Purpose: The general gap in the BIRADS lexicon between lesion description and categorization leads to Selleckchem Small molecule library very different recommendations in clinical breast radiology. This is particularly true for breast MRI. The third consensus meeting of course directors in breast imaging aimed at an increase in standardization of breast MRI.\n\nMaterials and Methods: Between 166 and 344 participants in the audience (A) and 9 and 13 expert panel participants (P) took part in an electronic wireless voting system. The audience consisted of 98% radiologists and 2% gynecologists (A: n =295; P: n = 12: radiologists 92 %/gynecologists 8 %). Of all participants, 62% had more than 10 years of experience in breast imaging and only 9% had less than 3 years of experience (P: 100% > 10 years of experience). The day before 44, clinically relevant, though unresolved questions were formulated by the expert panel.

All EBV-infected cells were found to be B lymphocytes About 90%

All EBV-infected cells were found to be B lymphocytes. About 90% of the infected B cells are found in the interfollicular regions of tonsils and adenoids and the remaining 10% are found within the follicles. There is no significant association between EBV infection, age (P = 0.324) and gender (P = 0.442).\n\nConclusion: EBV is associated with tonsillar hypertrophy and

is prevalent in 43% of our cases. EBV is only detected in B lymphocytes and we believe that B lymphocytes are sites of primary infection and latency. In situ hybridization is the gold standard for the detection of EBV in tissue. (C) 2011 Elsevier Ireland Ltd. All rights reserved.”
“The central dogma of gene expression is that DNA is transcribed into messenger RNAs, which in turn serve as the MK-1775 template for protein synthesis. The discovery of extensive transcription of large RNA transcripts that do not code for proteins, termed long noncoding RNAs (lncRNAs), provides an important new perspective on the centrality of RNA in gene regulation. Here, we

discuss genome-scale strategies to discover and characterize lncRNAs. An emerging theme from multiple model systems is that lncRNAs form extensive networks of ribonucleoprotein (RNP) complexes with numerous chromatin regulators and then target these enzymatic activities to appropriate locations in the genome. Consistent with this notion, lncRNAs can function as modular scaffolds to selleck chemicals specify higher-order organization in RNP complexes and in chromatin states. The importance of these modes of regulation is underscored by the newly recognized roles of long RNAs for proper gene control across all kingdoms of life.”
“A 7 yr old spayed female

Chihuahua presented for right hind limb lameness and reduced stifle range of motion. Radiographs showed a marked patella baja of the right stifle and evidence of a previous surgery to correct a medial patellar luxation. A tibial tuberosity osteotomy was performed to allow proximal translation of the tibial tuberosity, which was stabilized with a tibial tuberosity advancement plate. Four weeks postoperatively, lameness and articular range of motion were improved, and the use of anti-inflammatory and analgesic medications was discontinued. PFTα The dog was still ambulating well and had no lameness 12 mo postsurgically. (J Am Anim Hosp Assoc 2012; 48:113-117. DOI 10.5326/JAAHA-MS-5686)”
“Background and purpose: The aetiopathogenesis of fatigue in multiple sclerosis (MS) is not clear. It could be associated with structural changes of the central nervous system, but also with mood and sleep disorders. The purpose of the study was to evaluate frequency of fatigue and its association with sleep and mood disorders in MS patients.\n\nMaterial and methods: The examined group consisted of 122 MS patients (mean age 37.7 +/- 10.8 years).

Species heterogeneity (beta-diversity) among archaeological conte

Species heterogeneity (beta-diversity) among archaeological contexts was similar for the whole set of species, but markedly different when only native Amazonian species were included, suggesting the influence of pre-conquest

indigenous occupations on current homegarden species composition. Our findings show that the legacy of pre-Columbian occupations is visible in the most dynamic of all agroecosystems, adding another dimension to the human footprint in the Amazonian landscape.”
“The partitioning locus STB of the selfish plasmid, the 2 mu m circle, of Saccharomyces cerevisiae is essential for the propagation of this multi-copy extra-chromosomal DNA element with nearly chromosome-like stability. The functional competence of STB requires the plasmid-coded partitioning proteins Rep1 and Rep2 as well as host-coded proteins. Host factors that associate with STB in Selleckchem VX-689 a Rep1- and Rep2-dependent manner

also interact with centromeres, AZD2014 ic50 and play important roles in chromosome segregation. They include the cohesin complex and the centromere-specific histone H3 variant Cse4. The genetically defined point centromere of S. cerevisiae differs starkly from the much more widespread epigenetically specified regional centromeres of eukaryotes. The particularly small size of the S. cerevisiae centromere and the association of chromosome segregation factors with STB raise the possibility of an evolutionary link between these two partitioning loci. The unusual positive supercoiling harboured by the S. cerevisiae centromere and AZD7762 STB in vivo in their functional states, unveiled by recent experiments,

bolsters the notion of their potential descent from an ancestral plasmid partitioning locus.”
“Recent studies have reported high levels of fecal indicator enterococci in marine beach sand. This study aimed to determine the spatial and temporal variation of enterococcal abundance and to evaluate its relationships with microbial community parameters in Hawaii beach sand and water. Sampling at 23 beaches on the Island of Oahu detected higher levels of enterococci in beach foreshore sand than in beach water on a mass unit basis. Subsequent 8-week consecutive samplings at two selected beaches (Waialae and Kualoa) consistently detected significantly higher levels of enterococci in backshore sand than in foreshore/nearshore sand and beach water. Comparison between the abundance of enterococci and the microbial communities showed that enterococci correlated significantly with total Vibrio in all beach zones but less significantly with total bacterial density and Escherichia coli. Samples from the different zones of Waialae beach were sequenced by 16S rRNA gene pyrosequencing to determine the microbial community structure and diversity.

However, pathological evidence of the association between inflamm

However, pathological evidence of the association between inflammatory mediators and human anaphylaxis is insufficient.\n\nThe aim of this study was to better understand the relationship between in vivo production of inflammatory mediators and the pathogenesis of anaphylaxis. We also sought to evaluate mast cell activation in anaphylaxis.\n\nWe measured the Barasertib cell line concentrations of various inflammatory mediators in urine samples, which were collected from 32 anaphylactic patients during the onset of anaphlaxis and during clinical remission, 21 patients with asthma on acute

exacerbation and 15 healthy control subjects. Blood and urine specimens were collected from the patients after provocation test. Urinary leukotriene E4 (LTE4), 9 alpha, 11 beta-prostaglandin F2 (9 alpha, 11 beta-PGF2), eosinophil-derived neurotoxin (EDN) and leukotriene B4 glucuronide (LTBG) concentrations were determined by enzyme immunoassay, and the activity of plasma platelet-activating factor acetylhydrolase and serum tryptase concentration were

measured using commercially available kits.\n\nSignificantly higher concentrations of urinary LTE4 and 9 alpha, 11 beta-PGF2, which immediately decreased during clinical remission, were observed in the anaphylactic patients than in asthmatic patients on acute exacerbation and healthy control subjects. Concentrations of EDN and LTBG were not significantly different among the anaphylactic patients, asthmatic patients on

acute exacerbation and healthy subjects. There was a significant correlation between urinary LTE4 and 9 alpha, 11 beta-PGF2 concentrations in the anaphylactic patients (r=0.672, P=0.005, n=32). In addition, ABT-263 ic50 LTE4 concentration in patients with anaphylactic shock is significantly elevated compared with that in patients without anaphylactic shock.\n\nThis is a report on the significant increase in urinary LTE4 and 9 alpha, 11 beta-PGF2 concentrations during anaphylaxis. Urinary LTE4 and 9 alpha, 11 beta-PGF2 concentrations may be a reliable marker of endogenous production of inflammatory mediators associated with anaphylaxis.”
“A well established Napabucasin nmr method to analyze dynamical systems described by coupled nonlinear differential equations is to determine their normalmodes and reduce the dynamics, by adiabatic elimination of stable modes, to a much smaller system for the amplitudes of unstable modes and their nonlinear interactions. So far, this analysis is possible only for idealized symmetric model systems. We aim to build a framework in which realistic systems with less symmetry can be analyzed automatically. In this paper we present a first example of mode analysis with the assistance of numerical computation. Our method is illustrated using a model system for the ontogenesis of retinotopy, and the results reproduce those from theoretical analysis precisely. Aspects of organization generalized from this model system are discussed.”