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In 2013, the Qt Project announced a move away from Google’s V8 JavaScript engine to their own internal V4 JavaScript engine. Despite this, even today Qt still contains a V8 interpretation layer and V8 code in other parts of Qt. This paper aims to investigate why the decision to change interpreters was made and also to evaluate the aspects of Qt interpreted by V4 and what is interpreted by V8. With this defined, differences in secure coding techniques between these systems is examined and highlighted and why these techniques are important in the Qt environment.

It has been recognized that most of the Internet is not accessible through regular search engines and web browsers. This part of the web is known as dark web, and the surface is about 400 to 500 times larger than the size of the web that we know [1]. The goal of this project is to design a dark web crawler that can uncover any suspicious and malicious websites from the TOR (The Onion Router) network. The proposed system will create a database of suspicious and malicious websites by scraping relative linking attributes that may be contained within TOR network web pages. The proposed database automatically updates itself and it will archive previous versions of TOR sites while saving available working links. This will give law enforcement authorities the ability to search both the current TOR database and previous versions of the Database to detect suspicious and malicious websites.

The myotropic activity and mode of action of an endogenous corticotropin-releasing factor (CRF)-related diuretic peptide ( Acheta -DP) was investigated using isolated denervated foreguts from the house cricket, Acheta domesticus . Acheta -DP increased the frequency and amplitude of contractions of the foregut at a threshold concentration of 3.74 ± 0.002 n m . The response to the peptide was unaffected by tetrodotoxin (TTX), and is likely to be a direct action on the muscle cells. Acheta -DP caused a 10-fold increase in cyclic AMP production by isolated foreguts. The ability of IBMX to potentiate the myotropic activity of Acheta -DP suggests the peptide acts via a cyclic AMP-dependent mechanism. In support of this, forskolin produced a peptide-like response, and enhanced the effect of Acheta -DP. Myotropic activity was dependent on extracellular calcium, and was inhibited by the L-type calcium channel antagonist, nifedipine. Bay K 8644 enhanced the response of the foregut to both Acheta -DP and to dibutyryl cyclic AMP, suggesting that the physiological response arose from calcium influx through L-type calcium channels. It is proposed that Acheta -DP binds to a receptor on muscle fibre membranes activating adenylyl cyclase. The resultant increase in intracellular cyclic AMP is thought to open L-type calcium channels and thereby stimulate gut contractions.

An identical CRF-related diuretic peptide (Musca-DP) was isolated and characterized from whole-body extracts of the house fly, Musca domestica, and stable fly, Stomoxys calcitrans. The peptide stimulates cyclic AMP production in Manduca sexta Malpighian tubules and increases the rate of fluid secretion by isolated Musca domestica tubules. The 44-residue peptide, with a mol.wt. of 5180, is amidated, and has the primary structure: NKPSLSIVNPLDVLRQRLLLEIARRQMKENTRQVELNRAILKNV-NH2. Musca-DP has a high percentage of sequence identity with other characterized CRF-related insect diuretic peptides.

A diuretic peptide (Periplaneta-DP) has been isolated from extracts of whole heads of the cockroach, Periplaneta americana. The purified peptide increases cyclic AMP production and the rate of fluid secretion by isolated Malpighian tubules in vitro. In the fluid secretion assay, the response to native Periplaneta-DP is comparable to that obtained with crude extracts of cockroach corpora cardiaca, and the EC50 lies between 10(-8) and 10(-9) M. The primary structure of Periplaneta-DP was established as a 46-residue amidated peptide: T G S G P S L S I V N P L D V L R Q R L L L E I A R R R M R Q S Q D Q I Q A N R E I L Q T I-NH2. Periplaneta-DP is a further member of the recently established family of CRF-related insect diuretic peptides.

Previously, a corticotropin releasing factor (CRF)-like diuretic peptide (Man-duca-DH) has been isolated from Manduca sexta and shown to stimulate fluid excretion in vivo in post-eclosion Pieris rapae adults and in pre-wandering postfeeding Manduca sexta larvae. However, Manduca-DH was reported to have no effect on Malpighian tubules in vitro. Manduca-DH and [Nle2,11]-Manduca-DH were synthesized in Texas and assayed in London on isolated Malpighian tubules of Acheta domesticus. Man-duca-DH stimulated fluid secretion by about 60% of the maximum response achievable with extracts of corpora cardiaca and increased the production of cyclic AMP. In combination with 10−4moll−1 3-isobutyl-l-methyl xanthine (IBMX), Manduca-DH stimulated maximal secretion. A number of CRF-related peptides also stimulated fluid secretion and cyclic AMP production in cricket tubules, and the CRF antagonist α-helical-CRF[9–41] blocked the stimulation of fluid secretion by Manduca-DH. [Nle2,11]-Manduca-DH was more active than Manduca-DH in both assays, suggesting that methionine residues in the natural peptide may become oxidized. Taken in conjunction with previous in vivo studies, the present findings suggest that a Manduca-DH-like diuretic peptide is the hormone controlling post-eclosion diuresis in butterflies, and Manduca-DH was shown to stimulate both fluid secretion and cyclic AMP production in Malpighian tubules from 1–12 h posteclosion Pieris rapae adults. The function of the peptide in Manduca sexta is discussed.

Exogenous cAMP, cAMP analogues and forskolin all stimulated fluid secretion by the isolated Malpighian tubules of Acheta domesticus . IBMX potentiated the effects of 8-bromo cAMP and forskolin, and the diuretic activity of extracts of corpora cardiaca. The effects of forskolin and corpora cardiaca on cAMP production were determined on isolated tubules both in the presence and absence of IBMX. Such treatments increased intracellular levels of cAMP, with this response paralleling or preceding the increase in fluid secretion. Fluid secretion increased with intracellular cAMP concentrations up to about 8 μM, but further increases in cAMP were not associated with any further increases in fluid secretion. The adenylyl cyclase activity of Malpighian tubule plasma membrane preparations was investigated and shown to be stimulated in a dose-dependent manner by extracts of whole heads. Results are discussed in relation to the role of cAMP as a second messenger in the Malpighian tubules of Acheta , and consideration is given to the establishment of a convenient assay for diuretic peptides which stimulates adenylyl cyclase activity.

Manduca sexta diuretic peptide II (Mas-DPII) stimulates fluid secretion by adult Malpighian tubules and cyclic AMP production by larval proximal and adult tubules of M. sexta in a dose-dependent manner. Mas-DPII has no effect on fluid transport across the larval cryptonephric complex. M. sexta diuretic hormone (Mas-DH) and CRF-related insect diuretic peptides from Acheta domesticus, Locusta migratoria, and Periplaneta americana also cause similar increases in the production of cyclic AMP by the Malpighian tubules of both larval and adult M. sexta. Insect CRF-related diuretic peptides exhibit varying degrees of potency when assayed on Malpighian tubules from L. migratoria and A. domesticus. Sauvagine, bovine-CRF, and human-CRF have only a small, but significant, effect on cyclic AMP production by M. sexta Malpighian tubules. However, sauvagine, bovine-CRF, and sucker fish urotensin-I have no effect on L. migratoria tubules. Stimulation of cyclic AMP production by M. sexta Malpighian tubules could potentially be used as a screening assay to identify other insect CRF-related diuretic peptides.

Acheta diuretic peptide (Acheta-DP) is a corticotropin-releasing factor (CRF)-related peptide found in head extracts of the house cricket Acheta domesticus. The peptide causes a dose-dependent increase in fluid secretion by cricket Malpighian tubules isolated in vitro, and the apparent EC50 is 1.3 nmol l−1, which is within the physiological range for a peptide hormone. The CRF antagonist α-helical CRF(9-41) blocks the action of Acheta-DP in a dose-dependent manner, and the IC50 is estimated to be in the micromolar range. Addition of Acheta-DP to isolated Malpighian tubules is followed by a rapid and marked increase in the level of intracellular cyclic AMP. This precedes any change in voltage or fluid secretion, which strongly suggests that cyclic AMP is the intracellular mediator of Acheta-DP activity. Consistent with this, diuretic activity is potentiated by the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine, and there is a close relationship between the dose–response curves for cyclic AMP production and for fluid secretion. However, exogenous 8-bromo-cyclic AMP does not mimic all the effects of Acheta-DP, and the peptide may have a dual action on isolated tubules. Fluid secretion by tubules dosed repeatedly with Acheta-DP returns to near basal levels after 3–5 h. This cannot be explained by degradation of the peptide, but might be due in part to oxygen and/or metabolite deficiency. However, tubules that are refractory to Acheta-DP can be stimulated by forskolin, 8-bromo-cyclic AMP and extracts of corpora cardiaca, which is indicative of a homologous desensitization of membrane receptors for the diuretic peptide. Differences in the rate of secretion by morphologically distinct regions of cricket Malpighian tubules have been assessed. In unstimulated tubules, the rate of secretion per unit length by the short distal segment is about twice that of the main tubule. However, diuretic peptides (Acheta-DP and achetakinin-I) have little effect on distal tubule secretion, but evoke a two-to fourfold increase in fluid secretion by the main tubule segment.

A diuretic peptide Locusta-DP, identified by its ability to increase cyclic AMP production in locust Malpighian tubules in vitro, has been isolated and characterized from whole heads of Locusta migratoria. The purified peptide stimulates fluid secretion by Malpighian tubules maximally in vitro. The primary structure of Locusta-DP was established as a 46 residue amidated peptide: MGMGPSLSIVNPMDVLRQRLLLEIARRRLRDAEEQIKANKDFLQQI-NH2. Locusta-DP has 48% sequence identity with Acheta-DP and 49% identity with Manduca-DH, and provides further evidence for the presence of a family of diuretic peptides in insects.