Remarks on anomalous dissipation for passive scalars.

We consider the problem of anomalous dissipation for passive scalars advected by an incompressible flow. We review known results on anomalous dissipation from the point of view of the analysis of partial differential equations, and present simple rigorous examples of scalars that admit a Batchelor-type energy spectrum and exhibit anomalous dissipation in the limit of zero scalar diffusivity. This article is part of the theme issue 'Scaling the turbulence edifice (part 1)'.

Bulk RNA-Seq analysis to dissect the regulation of stigma position in tomato.

KEY MESSAGE: Transcriptomic analysis of tomato genotypes contrasting for stigma position suggests that stigma insertion occurred by the disruption of a process that finds a parallel in Arabidopsis gynoecium development. Domestication of cultivated tomato (Solanum lycopersicum L.) included the transition from allogamy to autogamy that occurred through the loss of self-incompatibilty and the retraction of the stigma within the antheridial cone. Although the inserted stigma is an established phenotype in modern tomatoes, an exserted stigma is still present in several landraces or vintage varieties. Moreover, exsertion of the stigma is a frequent response to high temperature stress and, being a cause of reduced fertility, a trait of increasing importance. Few QTLs for stigma position have been described and only one of the underlying genes identified. To gain insights on genes involved in stigma position in tomato, a bulk RNA sequencing (RNA-Seq) approach was adopted, using two groups of contrasting genotypes. Phenotypic analysis confirmed the extent and the stability of stigma position in the selected genotypes, whereas they were highly heterogeneous for other reproductive and productive traits. The RNA-Seq analysis yielded 801 differentially expressed genes (DEGs), 566 up-regulated and 235 down-regulated in the genotypes with exserted stigma. Validation by quantitative PCR indicated a high reliability of the RNA-Seq data. Up-regulated DEGs were enriched for genes involved in the cell wall metabolism, lipid transport, auxin response and flavonoid biosynthesis. Down-regulated DEGs were enriched for genes involved in translation. Validation of selected genes on pistil tissue of the 26 single genotypes revealed that differences between bulks could both be due to a general trend of the bulk or to the behaviour of single genotypes. Novel candidate genes potentially involved in the control of stigma position in tomato are discussed.

Fine mapping of the parthenocarpic fruit ( pat) mutation in tomato.

The parthenocarpic fruit ( pat) gene of tomato is a recessive mutation conferring parthenocarpy, which is the capability of a plant to set seedless fruits in the absence of pollination and fertilization. Parthenocarpic mutants offer a useful method to regulate fruit production and a suitable experimental system to study ovary and fruit development. In order to map the Pat locus, two populations segregating from the interspecific cross Lycopersicon esculentum x Lycopersicon pennellii were grown, and progeny plants were classified as parthenocarpic or wild-type by taking into account some characteristic aberrations affecting mutant anthers and ovules. Through bulk segregant analysis, we searched for both random and mapped AFLPs linked to the target gene. In this way, the Pat locus was assigned to the long arm of chromosome 3, as also confirmed by the analysis of a set of L. pennellii substitution and introgression lines. Afterwards, the Pat position was refined by using simple sequence repeats (SSRs) and conserved ortholog set (COS) markers mapping in the target region. The tightest COSs were converted into CAPS or SCAR markers. At present, two co-dominant SCAR markers encompassing a genetic window of 1.2 cM flank the Pat locus. Considering that these markers are orthologous to Arabidopsis genes, a positional cloning exploiting the tomato- Arabidopsis microsynteny seems to be a short-term objective.

The parthenocarpic fruit (pat) mutant of tomato (Lycopersicon esculentum Mill.) sets seedless fruits and has aberrant anther and ovule development.

Among the different sources of genetic parthenocarpy described in tomato, the mutation referred to as parthenocarpic fruit (pat) is of particular interest because of its strong expressivity and because it confers earlier ripening, higher fruit set and enhanced fruit quality. As a pleiotropic effect, pat flowers have aberrantly developing androecia and reduced male and female fertility. In this work we extend the early description of the pat phenotype by investigating the expression of parthenocarpy in three different environments and by using light and scanning electron microscopy to analyse the development of male and female floral organs. The degree of parthenocarpy was high in the three experimental environments and was characterised by a precocious initiation of ovary growth to pre-anthesis floral stages. Aberrations in anther development were evident at flower bud stages and resulted in shorter, irregular and teratoid organs. Ectopic production of carpel-like structures bearing external ovules was evident in the most severely altered androecia. Analysis of ovule development revealed that a fraction of pat ovules becomes aberrant from very early stages, having defective integument growth. Meiosis was irregular in aberrant ovules and megaspore or gamete production was severely hampered. The described pat syndrome suggests that parthenocarpy in this mutant could be a secondary effect of a gene controlling, at early stages, organ identity and development.

Disappearance of human platelet factor 4 (PF4) in rabbits: does an immediate component exist?

Twelve male New Zealand rabbits were injected with 21 micrograms/kg of human platelet factor 4 antigen (PF4). The decay of the protein followed a monoexponential curve for the first 5 mins, with a half-life (t 1/2) of 1.94 mins and a calculated concentration at 0 time (CO) of 79.4 ng/ml. Five rabbits were pre-treated with heparin (2.500 I.U. i.v.) and 3 mins later were injected with the same amount of PF4. PF4 decay followed a monoexponential curve with a t 1/2 of 25.3 mins, and with CO of 380.8 ng/ml. This value is not greatly different from the one calculated assuming an immediate and uniform distribution in plasma (482.7 ng/ml for a plasma volume of 43.5 ml/kg). The 12 rabbits injected with PF4 were divided in 3 groups, in which heparin was given at 10', 30' or 60' after PF4, respectively. After heparin the peak levels of PF4 were 139.9 ng/ml, 65.3 ng/ml and 52.7 ng/ml, respectively. The following monoexponential PF4 decay had t 1/2 of 20.7, 25.6 and 26.0 mins, respectively. In a separate group of 4 animals, we studied heparin decay after an intravenous bolus of 2.500 I.U. Heparin decay could not be described by a monoexponential equation and was different from the decay of PF4 injected after heparin. On the basis of the present data we suggest the presence of an immediate component of PF4 decay, most likely due to uptake by the tissues. Heparin pretreatment may avoid this uptake process.

Evidence of reduced atherosclerotic lesions in broad breasted white turkeys treated with oxprenolol.

Male Broad Breasted White Turkeys (BBWT) are naturally hypertensive and prone to develop atherosclerosis. Hypertension is characterized by high levels of circulating and tissue catecholamines; atherosclerosis affects mainly the aorto-iliac tract. To evaluate the effect of a beta-blocker on both hypertension and atherosclerosis, 2 groups of BBWT were studied. First group: 12 BBWT treated from the 8th week of age with daily p.o. placebo; second group: 6BBWT treated from the 8th week with 2 mg/kg p.o. daily oxprenolol. Blood pressure (BP) and heart rate (HR) were periodically measured with an indirect method. Seven and 5 BBWT of the first group were sacrificed at 24 and 51 weeks respectively. The 6 animals of the second group were sacrificed at 51 weeks. No significant difference in mean BP and HR values was found between the two groups of animals. On the contrary the oxprenolol treated group displayed a significant reduction in extent and severity of the atherosclerotic lesions. These results seem to substantiate that oxprenolol might positively interfere with the setting of atherosclerosis in these animals independently of BP reduction. One possible explanation could be a direct effect of oxprenolol on the arterial wall.

[Evaluation of the efficacy of various hypotensive drugs in broad-breasted white turkeys as an experimental model of arterial hypertension with high catecholamine levels]. / Valutazione dell'efficacia ipotensiva di farmaci diversi sul tacchino BBWT, modello sperimentale di ipertensione arteriosa ad alte catecolami ne.

Male Broad Breasted White Turkeys (BBWT) represent an experimental model of arterial hypertension characterized by high levels of circulating and tissue catecholamines. We thought interesting to evaluate the efficacy of the long term treatment with different antihypertensive drugs. 59 male BBWT were studied, divided in five groups. The first group (13 animals) was treated with placebo; the second (14 animals) with oxprenolol 4 mg/Kg/q.d.; the third (10 animals) with labetalol 25 mg/Kg/q.d.; the fourth (11 animals) with verapamil 15 mg/Kg/ q.d.; the fifth (11 animals) with captopril 8 mg/Kg/ q.d. and furosemide 2,5 mg/Kg/q.d. All drugs were given p.o, from the 8th to the 33rd week of age. Weekly or every two weeks Blood Pressure (BP) and Heart Rate (HR) were measured by an indirect method. In all animals BP progressively increased and HR progressively decreased with age. Only the labetalol-treated animals showed a significant reduction of BP and HR through the study period as compared with the placebo-treated animals. These results confirm the preminent role played by the high levels of circulating catecholamines in determining and maintaining the arterial hypertension.

[Use of labetalol in the treatment of hypertensive crises]. / Uso del labetalolo nel trattamento delle crisi ipertensive.

Labetalol, a combined alpha and beta adrenoceptor blocking drug, has been shown to be effective in the treatment of hypertensive crises when given intravenously. It also offers the advantage that treatment can be continued with the oral preparation. The purpose of our study was to evaluate if the administration of an intravenous bolus followed by an iv infusion and subsequently by the oral preparation might increase the efficacy of the drug without reducing its tolerance. Thirteen patients with severe essential hypertension and one with pheochromocytoma were treated during one or more hypertensive crises with Labetalol, 100 mg bolus i.v. injection in two minutes, followed by an intravenous infusion (2-4 mg/min for 60-90 minutes) and, one hour after the end of the infusion, by the oral preparation (200 mg t.i.d.). In 11 subjects with essential hypertension and in the patient with pheochromocytoma a 30% fall in systolic and diastolic blood pressure [from 240 +/- 10/155 +/- 6 mmHg (mean +/- 1 s.e.m.), to 162 +/- 8/111 +/- 6, p less than 0.01] was achieved within five minutes from the beginning of the treatment. Blood pressure remained well controlled thereafter, throughout the infusion period and during the first 24 hours of the oral administration. Heart rate fell simultaneously with the fall in blood pressure. Only in one patient blood pressure was not adequately controlled despite of the bolus and of an infusion at the rate of 4 mg/min for 20 minutes. In another case the fall in pressure caused near-fainting and the infusion was therefore not started. No other side effects were encountered except for transient orthostatic hypotension. We conclude that the administration of a bolus plus infusion of Labetalol is more effective than single or repeated boluses or graded infusions and it is equally well tolerated.

Changes in ventricular myosin properties during broad breasted white turkey (BBWT) development.

This paper reports the following data with regard to the BBWT cardiovascular system: 1) Arterial Blood pressure progressively increases from 1 to 12 month of age, accompanied by marked left ventricular hypertrophy; 2) The myosin ATPase activity is enhanced about three times; 3) No differences in myosin light chain pattern is observed; 4) The peptide pattern obtained after chymotryptic digestion of the myosin molecule shows that some peptides, which are not evident or barely discernible, in 1 month old animal, are present in the adult one. These findings are surprising because it is well known that the ATPase activity decreases with age and hypertrophy. It is possible that other factors, as the levels of circulating cathecolamines or the thyroid hormones, are involved in the control of myosin synthesis and consequently in its ATPase activity.

[Changes of the permeability of the aortic endothelium in renovascular hypertension in the rat (preliminary data)]. / Modificazioni della permeabilita' dell'endotelio aortico nell'ipertensione renovascolare del ratto (dati preliminari).

The permeability of the endothelium of the aorta in hypertensive rats with normal and high plasma renin activity was studied with colloidal iron. In the former it was normal while in the latter it was markedly increased. It is concluded that the increased permeability is due to the high renin and not to the elevated blood pressure.