Protection against cardiac ischemia-reperfusion injury by hypothermia and by inhibition of succinate accumulation and oxidation is additive.

Hypothermia induced at the onset of ischemia is a potent experimental cardioprotective strategy for myocardial infarction. The aim of our study was to determine whether the beneficial effects of hypothermia may be due to decreasing mitochondria-mediated mechanisms of damage that contribute to the pathophysiology of ischemia/reperfusion injury. New Zealand male rabbits were submitted to 30 min of myocardial ischemia with hypothermia (32 °C) induced by total liquid ventilation (TLV). Hypothermia was applied during ischemia alone (TLV group), during ischemia and reperfusion (TLV-IR group) and normothermia (Control group). In all the cases, ischemia was performed by surgical ligation of the left anterior descending coronary artery and was followed by 3 h of reperfusion before assessment of infarct size. In a parallel study, male C57BL6/J mice underwent 30 min myocardial ischemia followed by reperfusion under either normothermia (37 °C) or conventionally induced hypothermia (32 °C). In both the models, the levels of the citric acid cycle intermediate succinate, mitochondrial complex I activity were assessed at various times. The benefit of hypothermia during ischemia on infarct size was compared to inhibition of succinate accumulation and oxidation by the complex II inhibitor malonate, applied as the pro-drug dimethyl malonate under either normothermic or hypothermic conditions. Hypothermia during ischemia was cardioprotective, even when followed by normothermic reperfusion. Hypothermia during ischemia only, or during both, ischemia and reperfusion, significantly reduced infarct size (2.8 ± 0.6%, 24.2 ± 3.0% and 49.6 ± 2.6% of the area at risk, for TLV-IR, TLV and Control groups, respectively). The significant reduction of infarct size by hypothermia was neither associated with a decrease in ischemic myocardial succinate accumulation, nor with a change in its rate of oxidation at reperfusion. Similarly, dimethyl malonate infusion and hypothermia during ischemia additively reduced infarct size (4.8 ± 2.2% of risk zone) as compared to either strategy alone. Hypothermic cardioprotection is neither dependent on the inhibition of succinate accumulation during ischemia, nor of its rapid oxidation at reperfusion. The additive effect of hypothermia and dimethyl malonate on infarct size shows that they are protective by distinct mechanisms and also suggests that combining these different therapeutic approaches could further protect against ischemia/reperfusion injury during acute myocardial infarction.

Correction to: Protection against cardiac ischemia-reperfusion injury by hypothermia and by inhibition of succinate accumulation and oxidation is additive.

The original version of this article unfortunately contained a mistake.

ACE inhibition in goats under fixed-time artificial insemination protocol increases the pregnancy rate and twin births.

To assess the effect of the angiotensin-converting enzyme (ACE) inhibition on the efficiency of the fixed-time artificial insemination (TAI), 69 goats were divided randomly into two groups: enalapril (n = 35) and control (n = 34). In the experiment, all animals underwent the protocol of fixed-time artificial insemination for 12 days. Enalapril group received enalapril maleate dissolved in saline (Enalapril, Lab Teuto Ltda) subcutaneously at the following doses: 0.2 mg/kg/day in D0-D2; 0.3 mg/kg/day in D3-D6 and 0.4 mg/kg/day in D7-D11. The control group received the corresponding volume of 0.9% saline solution. We performed a single insemination 36 hr after sponge removal using frozen semen from two adult male goats with recognized fertility. The ultrasound pregnancy diagnosis was 30 days after the artificial insemination (AI). There was significant increase in pregnancy rates and twinning as well as a decrease in foetal loss in animals receiving enalapril (p < .01). The use of ACE inhibitors during the TAI protocol was shown to be a promising alternative to increase the efficiency of such reproductive biotechnology.

Analysis of genetic diversity of Laeliinae (Orchidaceae) in the State of Sergipe using ISSR markers.

The Orchidaceae represent one of the largest and most diverse families on the planet. However, this family is constantly threatened by predators and by the advancement of urban centers over its natural habitats. The objective of this study was to use inter-simple sequence repeat markers to evaluate the genetic diversity between orchid accessions of the Laeliinae subtribe, which comprise part of the Orchidaceae study collection at the Department of Agronomic Engineering of the Federal University of Sergipe. DNA was extracted from each specimen by using an adapted 2% cetyltrimethyl ammonium bromide protocol. Similarity between individuals was calculated using the Jaccard method. Clustering was carried out by the unweighted pair group method with arithmetic mean method, with resampling and 10,000 bootstraps. Eighty-seven fragments were obtained, all of which were polymorphic, revealing high variability between accessions. The mean similarity was 35.77% between Encyclia sp individuals, and 35.90% between specimens of Cattleya tigrina. For Epidendrum secundum, a relationship between geographic and genetic distances was observed, and the accession collected in the southern part of the State of Sergipe (Serra de Itabaiana National Park) was more divergent than that of the other parts of the state. The data generated in this study will guide further research aimed at the ex situ conservation of these materials.

Assessing families' and patients' attitudes toward brain donation for research purposes in a Brazilian population sample.

The neuropathological examination of postmortem human brain tissue is an essential resource for the definitive diagnosis and research on neurodegenerative diseases. Due to the growing need of donated brains to supply the Brain Banks, the understanding of the factors associated with the consent for the donation in our context is an important aspect of the process of brain donation. The verbal answers and the donation consent rate were evaluated in three groups: 30 relatives of patients who underwent verification of the cause of death, 14 patients assisted at a neurology ambulatory outpatient clinic, and 18 patients' relatives. The donation consent rates were of 46.6, 92.8 and 88.8 %, respectively. The main reasons for refusal were the disagreement with the autopsy, philosophical and religious issues, objections from other family members, and the consideration of the wishes of the deceased. The consent was specially motivated by the interest in the advances of scientific knowledge, altruistic reasons and the personal experiences with the disease. Factors as the emotional fragility at the moment of death, the beliefs, family matters, and the lack of knowledge are key elements in the donation process. Future goals include the establishment of a brain donor program with the support of academic institutions, hospitals, scientists, community, patient's associations and autopsy assistants. Approaching patients and relatives in specialized ambulatories clinic during assistance is probably the most efficient mean of obtaining brains for research.

Inhibition of angiotensin-converting enzyme increases oestradiol production in ewes submitted to oestrous synchronization protocol.

This study aimed at evaluating the effects of angiotensin-converting enzyme inhibitor (enalapril) and angiotensin II antagonist (valsartan) on the oestradiol and progesterone production in ewes submitted to oestrous synchronization protocol. The animals were weighed and randomly divided into three groups (n = 7). A pre-experiment conducted to verify the effectiveness and toxicity of enalapril (0.5 mg/kg LW) and valsartan (2.2 mg/kg LW) showed that, in the doses used, these drugs were effective in reducing blood pressure without producing toxic effects. In the experiment, all animals were subjected to oestrous synchronization protocol during 12 days. On D10, D11 and D12, animals received saline, enalapril or valsartan (same doses of the pre-experiment), according to the group randomly divided. The hormonal analysis showed an increase in oestradiol on the last day of the protocol (D12) in animals that received enalapril (p < 0.05), but not in other groups, without changing the concentration of progesterone in any of the treatments. It is concluded that valsartan and enalapril are safe and effective subcutaneously for use in sheep and that the angiotensin-converting enzyme (ACE) inhibition with enalapril leads to an increase in oestradiol production near ovulation without changing the concentration of progesterone. This shows that ACE inhibition may be a useful tool in reproductive biotechnologies involving induction and synchronization of oestrus and ovulation in sheep.

Sex-Specific Patterns of Cerebral Atrophy and Enlarged Perivascular Spaces in Patients with Cerebral Amyloid Angiopathy and Dementia.

BACKGROUND AND PURPOSE: Cerebral amyloid angiopathy is characterized by amyloid ß deposition in leptomeningeal and superficial cortical vessels. Cognitive impairment is common and may occur independent of concomitant Alzheimer disease neuropathology. It is still unknown which neuroimaging findings are associated with dementia in cerebral amyloid angiopathy and whether they are modulated by sex. This study compared MR imaging markers in patients with cerebral amyloid angiopathy with dementia or mild cognitive impairment or who are cognitively unimpaired and explored sex-specific differences. MATERIALS AND METHODS: We studied 58 patients with cerebral amyloid angiopathy selected from the cerebrovascular and memory outpatient clinics. Clinical characteristics were collected from clinical records. Cerebral amyloid angiopathy was diagnosed on MR imaging on the basis of the Boston criteria. Visual rating scores for atrophy and other imaging features were independently assessed by 2 senior neuroradiologists. RESULTS: Medial temporal lobe atrophy was higher for those with cerebral amyloid angiopathy with dementia versus those cognitively unimpaired (P = .015), but not for those with mild cognitive impairment. This effect was mainly driven by higher atrophy in men with dementia, compared with women with and without dementia (P = .034, P = .012; respectively) and with men without dementia (P = .012). Enlarged perivascular spaces in the centrum semiovale were more frequent in women with dementia versus men with and without dementia (P = .021, P = .011; respectively) and women without dementia (P = .011). CONCLUSIONS: Medial temporal lobe atrophy was more prominent in men with dementia, whereas women showed a higher number of enlarged perivascular spaces in the centrum semiovale. Overall, this finding suggests differential pathophysiologic mechanisms with sex-specific neuroimaging patterns in cerebral amyloid angiopathy.

Investigation of colloidal stability and insulation characteristics of magnetic oils.

Superparamagnetic iron-oxide (SPIO) particles were synthesized by the co-precipitation method and the oleic acid-coated SPIO (OA-SPIO) was then obtained by a surface grafting procedure. A stock sample of magnetic oil (MO) with 1.6% particle volume fraction (VF) was obtained by dispersing the OA-SPIO in insulating naphthenic oil. The MO stock sample was diluted in the same naphthenic oil to yield MO with 0.1, 0.04, 0.02, and 0.01% VF. Moreover, the 0.04% VF MO sample was manipulated to yield MO samples with water content of 26, 37, and 63 mg L(-1). The spinel structure of OA-SPIO was assessed by XRD and the average diameter of 8.3 nm was provided by TEM analysis. The saturation magnetization at room temperature (RT) was 70 emu/g and no remanence or coercivity was observed. The average hydrodynamic diameter (D(H)) of the colloidal particles suspended within the 0.04% VF MO sample was 58 nm. After aging for 30 days at RT no change was observed for the lowest water content MO sample (26 mg L(-1)). However, D(H) equals to 270 nm was observed for the highest water content MO sample (63 mg L(-1)). The MO samples with 26 mg L(-1) water content were found stable under heating at 90 degrees C for all VF investigated. We found the insulation resistance dropping significantly as VF and temperature increases. The lowest value found was 11 GOhms for the 0.1% VF at 60 degrees C, which is an acceptable value for MO.

Microbial diversity in the larval gut of field and laboratory populations of the sugarcane weevil Sphenophorus levis (Coleoptera, Curculionidae).

The sugarcane weevil, Sphenophorus levis, is a wide-spread sugarcane pest in Brazil. Sphenophorus levis may depend on microorganisms that inhabit its intestinal tract. We examined the diversity of the gut microbiota of S. levis, which was characterized using culture-dependent and culture-independent methods. Analysis of 16S rRNA amplified directly from the gut community revealed the presence of 14 genera, one group from the Candidatus category, one uncultured group assigned to the family Flavobacteriaceae, and one uncultured group assigned to the family Enterobacteriaceae; all of them are members of the Alpha-Proteobacteria, Beta-Proteobacteria, Gamma-Proteobacteria, Firmicutes, and Bacteroidetes phyla. Microorganisms isolated through culture-dependent methods were classified according to morphological parameters and by 16S rRNA gene sequences. In addition to bacteria, four filamentous fungi were isolated. A higher bacterial diversity was observed in field populations of larvae than in laboratory populations, according to the Shannon index (Field H' = 3.36; Laboratory H' = 3.26). Five genera of bacteria and two filamentous fungi were found to have cellulolytic activity. This is the first report of S. levis gut microbiota; it may contribute to development of strategies for controlling this sugarcane pest.

Inhibition of starch digestion by flavonoids: Role of flavonoid-amylase binding kinetics.

In this study, kinetics of binding between α-amylase and green tea flavonoids were investigated by fluorescence quenching (FQ). Their effect on α-amylase inhibition was evaluated. Whereas epicatechin (EC) and epigallocatechin (EGC) exhibited slow binding kinetics (in the order of minutes), epicatechin gallate (ECG) and epigallocatechin gallate (ECGC) exhibited very rapid binding (in the order of seconds) with Human Salivary α-amylase (HSA) and Porcine Pancreatic α-amylase (PPA). EGCG reached maximum inhibition of HSA and PPA with short incubation time whereas maximum inhibition of HSA and PPA by EC was reached only after 45 to 60 min of incubation. Similar results with ECG and EGC, but not in line with FQ kinetics, highlighted possible interferences of starch-flavonoid interaction in the binding and inhibition process. These results suggest that incubation times of enzymes and flavonoids shall be evaluated prior to enzyme inhibition testing in order to ensure consistent and reliable results.

Metabolic Reprogramming and Oncogenesis: One Hallmark, Many Organelles.

The process of tumorigenesis can be described by a series of molecular features, among which alteration of cellular metabolism has recently emerged. This metabolic rewiring fulfills the energy and biosynthetic demands of fast proliferating cancer cells and amplifies their metabolic repertoire to survive and proliferate in the poorly oxygenated and nutrient-deprived tumor microenvironment. During the last decade, the complex reprogramming of cancer cell metabolism has been widely investigated, revealing cancer-specific metabolic alterations. These include dysregulation of glucose and glutamine metabolism, alterations of lipid synthesis and oxidation, and a complex rewiring of mitochondrial function. However, mitochondria are not the only metabolically active organelles within the cell, and other organelles, including lysosomes, peroxisomes, and endoplasmic reticulum, harbor components of the metabolic network. Of note, dysregulation of the function of these organelles is increasingly recognized in cancer cells. However, to what extent these organelles contribute to the metabolic reprogramming of cancer is not fully understood. In this review, we describe the main metabolic functions of these organelles and provide insights into how they communicate to orchestrate a coordinated metabolic reprogramming during transformation.

Murine melanoma cells incomplete reprogramming using non-viral vector.

OBJECTIVES: The reprogramming of cancer cells into induced pluripotent stem cells or less aggressive cancer cells can provide a modern platform to study cancer-related genes and their interactions with cell environment before and after reprogramming. Herein, we aimed to investigate the reprogramming capacity of murine melanoma B16F10 cells. MATERIALS AND METHODS: The B16F10 was transfected using non-viral circular DNA plasmid containing the genes Sox-2, Oct4, Nanog, Lin28 and green fluorescent protein (GFP). These cells were characterized by immunofluorescence, analysis RT-PCR and cell cycle. RESULTS: Our results demonstrated for the first time that reprogramming of B16F10 may be induced using non-viral minicircle DNA containing the four reprogramming factors Oct4, Sox2, Lin 28, Nanog (OSLN) and the GFP reporter gene. The resulting clones are composed by epithelioid cells. These cells display characteristics of cancer stem cells, thus expressing pluripotent stem cell markers and dividing asymmetrically and symmetrically. Reprogrammed B16F10 cells did not form teratomas; however, they showed the suppression of tumourigenic abilities characterized by a reduced tumour size, when compared with parental B16F10 cell line. In contrast to parental cell line that showed accumulation of the cells in S phase of cell cycle, the cells of reprogrammed clones are accumulated in G1 phase. Long-term cultivation of reprogrammed B16F10 cells induces regression of their reprogramming. CONCLUSIONS: Our data imply that in result of reprogramming of B16F10 cells less aggressive Murine Melanoma Reprogrammed Cancer Cells may be obtained. These cells represent an interesting model to study mechanism of cells malignancy as well as provide a novel tool for anti-cancer drugs screening.

Repercussions of growth path on carcass characteristics, meat colour and shear force in Alentejana bulls.

The aim of this study was to evaluate the carcass and meat characteristics of eight muscles from bulls with distinct growth paths. A total of 40 Alentejana male calves were allocated to two distinct feeding regimes. In the continuous growth (CG) system, the animals were fed concentrates plus hay and were slaughtered at 18 months of age. On the other hand, in the discontinuous growth (DG) system, the animals were fed hay until 15 months of age; the cattle were then fed the same diet provided to the CG group from 15 to 24 months of age. The DG reduced hot carcass weight, fatness and dressing %, but the proportions of fat, bone and muscle tissues in the leg were not affected. In contrast, there was a positive impact of compensatory growth on supraspinatus, triceps brachii, semitendinosus, biceps femoris muscle tenderness, overcoming the negative effects of age at slaughter. The reasons for such improvement in meat tenderness were not related to intra-muscular fat content or myofibrillar protein degradation values. An association between tenderness and muscle collagen properties was not established. The results indicate that the compensatory growth has a muscle-dependent effect.

Shortcuts in genome-scale cancer pharmacology research from multivariate analysis of the National Cancer Institute gene expression database.

Application of a soft multivariate statistical procedure, called PLS, partial least squares modelling in latent variables or projections to latent structures, allows extensive exploitation of the enormous amount of information embedded in the National Cancer Institute gene expression and antitumour screen databases. Interpretation of the statistical results provides new significant biological insights such as classification of human tumour cell lines based on their gene expression patterns, evaluation of the influence of gene transcripts on drug efficacy and assessment of their selectivity for classes of compounds which act by the same mechanism, and identification of uncharacterized gene expression targets involved in cancer chemotherapy. Among them, the transcripts GC11121, GC17689, and GC18564 (unknown gene products extremely selective for RNA/DNA antimetabolites) are indicated by the present work as deserving high priority in future molecular studies.

Contrasting cellularity on fat deposition in the subcutaneous adipose tissue and longissimus lumborum muscle from lean and fat pigs under dietary protein reduction.

The production of pork with high amounts of intramuscular fat (IMF) without an increase in subcutaneous fat is highly desirable for the pig industry and consumers. Herein, we question the impact of dietary protein reduction (18% v. 13%) on fat deposition in the subcutaneous adipose tissue (SAT) and longissimus lumborum (LL) muscle using genetically diverse pigs for body fatness (lean v. fat). A clear effect of genotype was observed on plasma insulin (P=0.004) and leptin (P<0.001), as well as on backfat thickness (P<0.001), with the fat pigs having higher values. Accordingly, IMF was higher in the fat pigs, when compared with their lean counterparts (P=0.003), which was supported by enlarged adipocytes (P<0.001). The area of lipid droplets within the LL fibres (P=0.039) and extramyocellular lipids number (P=0.017) were increased in pigs fed reduced protein diets, regardless of genotype, which is consistent with higher levels of plasma triacylglycerols (P=0.002). The gene-expression pattern of lipogenic factors in the SAT was distinct from the LL muscle. In the SAT, PPARG expression was similar among genotypes (P>0.05), whereas in the LL muscle it was higher in the lean pigs (P=0.023), especially when fed on low protein diet (P=0.057). The CEBPA and FABP4 mRNA levels were increased in the SAT of fat pigs (P<0.001), without changes in the LL muscle (P>0.05). The influence of diet on FABP4 expression in the SAT was dependent on pig's genetic background (P=0.005). In conclusion, fat deposition was clearly influenced by genotype and, to a lesser extent, by dietary protein level, the SAT being more sensitive than the LL muscle. One can speculate that the pathways involved in lipid metabolism are downregulated in intramuscular adipocytes when compared with SAT fat cells. This result might be a direct consequence of the relatively low proportion of adipocytes found in the LL muscle.

Negative correlation between phospholipase and esterase activity produced by Fusarium isolates.

Fusarium species have emerged as one of the more outstanding groups of clinically important filamentous fungi, causing localized and life-threatening invasive infections with high morbidity and mortality. The ability to produce different types of hydrolytic enzymes is thought to be an important virulence mechanism of fungal pathogens and could be associated with the environment of the microorganism. Here, we have measured the production of two distinct lipolytic enzymes, phospholipase and esterase, by sixteen Fusarium isolates recovered from the hospital environment, immunocompromised patients' blood cultures, foot interdigital space scrapings from immunocompromised patients, and foot interdigital space scrapings from immunocompetent patients (4 isolates each). Fourteen of these 16 isolates were identified as Fusarium solani species complex (FSSC) and two were identified as F. oxysporum species complex (FOSC). Some relevant genus characteristics were visualized by light and electron microscopy such as curved and multicelled macroconidia with 3 or 4 septa, microconidia, phialides, and abundant chlamydospores. All Fusarium isolates were able to produce esterase and phospholipase under the experimental conditions. However, a negative correlation was observed between these two enzymes, indicating that a Fusarium isolate with high phospholipase activity has low esterase activity and vice versa. In addition, Fusarium isolated from clinical material produced more phospholipases, while environmental strains produced more esterases. These observations may be correlated with the different types of substrates that these fungi need to degrade during their nutrition processes.

A green strategy for desorption of trihalomethanes adsorbed by humin and reuse of the fixed bed column.

The objective of the present work was to develop a thermal desorption method for the removal of trihalomethanes (THM) adsorbed by humin, followed by multiple recycling of the fixed bed column in order to avoid excessive consumption of materials and reduce operating costs. The results obtained for adsorption on a fixed bed column confirmed the effectiveness of humin as an adsorbent, extracting between 45.9% and 90.1% of the total THM (TTHM). In none of the tests was the column fully saturated after 10h. Experiments involving thermal desorption were used to evaluate the potential of the technique for column regeneration. The adsorptive capacity of the humin bed increased significantly (p<0.05) between the first and fifth desorption cycle, by 18.9%, 18.1%, 24.2%, 20.2% and 24.2% for CHBr(3), CHBr(2)Cl, CHBrCl(2), CHCl(3) and TTHM, respectively.

Effect of low- and high-forage diets on meat quality and fatty acid composition of Alentejana and Barrosã beef breeds.

This study investigated the effects of genotype and diet on meat fat composition and palatability obtained from Alentejana (AL) and Barrosã (BA) breeds. Herein, 20 males from each breed allocated at 11 months of age were fed ad libitum a low-forage diet or a high-forage diet and slaughtered at 18 months of age. Trained sensory panel analysis found that the longissimus lumborum (Ll) muscle from BA had higher tenderness, juiciness and overall acceptability scores than the AL breed. The highest scores for those attributes were observed in the BA breed fed the high-forage diet. Regarding the semitendinosus (St) muscle, breed was a source of variation of tenderness scores. In contrast to the Ll muscle, the highest tenderness scores for the St muscle were observed in the AL breed. The intramuscular fat (IMF) content was positively correlated with tenderness, juiciness and overall acceptability in Ll muscle and negatively correlated with flavour in the St muscle. The levels of 14:0 and 16:0, 16:1c9, 18:1c9 and 18:1c11 were positively correlated to juiciness, tenderness and overall acceptability in the Ll muscle. These correlations were not observed in the St muscle, which may be related to its low IMF content. Nonetheless, negative correlations were observed for the St muscle between flavour and 14:0, 16:0 and 18:0 FA contents.The IMF varied widely in the Ll but not in the St muscle. The latter had higher levels of 16:1c9 and trans fatty acids (∑TFA) in the BA than in the AL breed. Regarding the Ll muscle, the BA had higher amounts of 14:0, 16:0, 16:1c9, 18:0, 18:1c9, 18:1c11, saturated fatty acids (∑SFA), cis monounsaturated fatty acids (∑cis MUFA), ∑TFA and n-3 polyunsaturated fatty acids (∑n-3 PUFA) than the AL breed. The diet exerted an influence on the IMF content and on the levels of 14:0, 16:0, 16:1c9, 18:0, 18:1c9, 18:1c11, ∑SFA, ∑cis MUFA and ∑TFA in both Ll and St muscles. Moreover, the levels of ∑n-3 PUFA in the Ll muscle and 18:2n-6, 20:4n-6, ∑n-6 PUFA and ∑PUFA in the St muscle were influenced by diet. The results obtained in this study, with two Portuguese breeds, confirm that genetic background plays a major role in the determination of meat eating quality.

Environmental strategies to remove volatile aromatic fractions (BTEX) from petroleum industry wastewater using biomass.

This work investigates the potentials of peat and angico hardwood sawdust to remove BTEX (benzene, toluene, ethylbenzene, and isomers of xylene) from the produced water discharged into aquatic systems during petroleum extraction. Peat and angico sawdust samples were pyrolyzed at 500°C, and found to contain n-alkenes, n-alkanes and pentacyclic triterpenes (peat), and 4-methoxyphenol, 1,4-dimethoxyphenol and 1,3,4-trimethoxyphenol (angico sawdust). In batch experiments, the removal capacities using peat were 32.4%, 50.0%, 63.0%, 67.8%, and 61.8% for benzene, toluene, ethylbenzene, m,p-xylenes and o-xylene, respectively. This compared with removal capacities using angico sawdust of 20.2%, 36.4%, 52.8%, 57.8%, and 53.7% for these compounds respectively, demonstrating the superior performance of the peat.