A new species of thrips-parasitic nematode, Thripinema usitatum n. sp. (Tylenchomorpha: Allantonematinae), is described from thrips collected from flowers in Hainan Province, China. The species is identified using an integrative approach combining detailed morphology, molecular phylogenetic analyses, and biological observations. Thripinema usitatum n. sp. exhibits pronounced sexual dimorphism and a complex life cycle, including obese parasitic females, vermiform infective females, and free-living males with degenerate feeding structures within the body of thrips. The new species is distinguished from its congeners by the absence of a stylet in free-living males, a distinctive two-part bursa extending nearly to the tail terminus, and characteristic shapes of parasitic females and male tails. Molecular characterization was performed using three markers (18S rRNA, 28S D2–D3 rRNA, and mitochondrial cytochrome c oxidase subunit I, mtCOI). Phylogenetic analyses based on 28S D2–D3 rRNA and mtCOI partial sequences consistently recovered T. usitatum n. sp. as a well-supported, monophyletic lineage clearly separated from other entomophilic nematodes. Among the markers examined, mtCOI provided the highest discriminatory power. Biological observations revealed that T. usitatum n. sp. infects thrips at all developmental stages, with a strong prevalence in adult females. Multiple nematode life stages frequently co-occurred within individual hosts, and infection intensities ranged from 1 to 433 nematodes per thrips. These results expand the known diversity of Thripinema and provide a robust framework for future systematic and ecological studies of thrips-parasitic nematodes.

A class of sequences called L-sequences is introduced, each one being a subsequence of a Collatz sequence. Every ordered pair $(v,w)$ of positive integers determines an odd positive integer P such that there exists an L-sequence of length n for every positive integer n, each term of which is congruent to P modulo $2^{v+w+1}$. The smallest possible initial term of such a sequence is described. If $3^v>2^{v+w}$ the L-sequence is increasing. Otherwise, it is decreasing, except if it is the constant sequence P. A central role is played by Bezout’s identity.

During investigation of common linnet (Linaria cannabina) blood using the buffy coat method one bird with microfilariae in the blood was found. The morphometric description of adult worms corresponded to the Chandlerella sinensis. This species was found for the first time in common linnets. DNA sequences of cox1 and 28S gene fragments of adult worm recovered during necropsy was identical to that from the microfilariae in the bird blood. Phylogenetic analysis of the cox1 gene fragment clustered this parasite with Chandlerella quiscali. Histological examination revealed the presence of microfilariae in the lumen of small capillaries and other blood vessels in different organs, but no inflammations were notice. The greatest number of microfilariae was in the lungs. Even if there was no inflammation, but vessels associated with the lungs were markedly distended with blood, parabronchial walls were thickened and, in some cases, almost completely obstructing the lumen. The large number of microfilariae in lungs indicates possible disturbance of gas exchange in the lungs adversely affected the ability of the bird to exercise and made breathing difficult at rest. The investigation of circadian rhythm of the microfilariae showed that C. sinensis microfilariae in blood of common linnet were more numerous at night and morning and less numerous at midday. The survival rate of mosquitoes infected with C. sinensis microfilariae was significantly lower than that of uninfected mosquitoes.

Let $S=\{s_{1}, s_{2}, \ldots \}$ be an unbounded sequence of positive integers with $s_{n+1}/s_{n}$ approaching $\alpha $ as $n\rightarrow \infty $ and let $\beta>\max (\alpha , 2)$. We show that for all sufficiently large positive integers l, if $A\subset [0, l]$ with $l\in A$, $\gcd A=1$ and $|A|\geq (2-{k}/{\lambda \beta })l/(\lambda +1)$, where $\lambda =\lceil {k}/{\beta }\rceil $, then $kA\cap S\neq \emptyset $ for $2<\beta \leq 3$ and $k\geq {2\beta }/{(\beta -2)}$ or for $\beta>3$ and $k\geq 3$.

Prior studies have found that subjects prefer an improving sequence of incomeover a constant sequence, even if the constant sequence offers a largerpresent-discounted value. However, little is known about how these preferencesvary with the size of the wage payments. In each of four studies, we find apositive relationship between the preference for increasing payments and thesize of the payments. We find no evidence that our measure of the decreasingmarginal utility of money is associated with this relationship. Additionally, wefind weak evidence in support of a theoretical prediction that the differencebetween the preference for increasing wage payments and the preference forincreasing nonwage payments will be largest for intermediate amounts. We do notfind a relationship between the preference for increasing payments and thepreference for improving nonmonetary sequences. Finally, the relationshipbetween the preference for increasing payments and the size of the payments doesnot appear to be sensitive to the precise specification of the increases.

Recently, Scholten and Read (2014) found new violations of dominance in intertemporal choice. Although adding a small receipt before a delayed payment or adding a small delayed receipt after an immediate receipt makes the prospect objectively better, it decreases the preference for that prospect (better is worse). Conversely, although adding a small payment before a delayed receipt or adding a small delayed payment after an immediate payment makes the prospect objectively worse, it increases the preference for that prospect (worse is better). Scholten and Read explained these violations in terms of a preference for improvement. However, to produce violations such as these, we find that the temporal sequences need not be constructed as Scholten and Read suggested. In this study, adding a small receipt before a dated receipt (thus constructed as improving) or adding a receipt after a dated payment (thus constructed as improving) decreases preferences for those prospects. Conversely, adding a small payment after a dated receipt (thus constructed as deteriorating) or adding a small payment before a delayed payment (thus constructed as deteriorating) increases preferences for those prospects.

A new species of dorylaimid nematode, Aporcelinus abeokutaensis sp. n., collected from a watermelon field in Nigeria, is described, illustrated and molecularly (D2–D3 28S ribosomal DNA) studied. It is characterized by its 1.18–1.52-mm-long body, lip region offset by weak constriction, 15.5–17.5 μm broad with perioral liplets, odontostyle 18–21.5 μm long at its dorsal side or 1.1–1.3 times the lip region diameter, neck 333–401 μm long, pharyngeal expansion occupying 45–51% of total neck length, uterus simple and 0.7–1.5 times the corresponding body diameter long, V = 48–53, tail conical with finely rounded tip (33–52 μm long, c = 26–41, c′ = 1.3–1.9) and a variably distinct dorsal concavity, and male unknown. Molecular analysis reveals that the new species grouped with other species of Aporcelinus in a highly supported clade, confirming the monophyly of the genus.

Let β>1 be a real number, and let {ak} be an unbounded sequence of positive integers such that ak+1/ak≤β for all k≥1. The following result is proved: if n is an integer with n>(1+1/(2β))a1 and A is a subset of {0,1,…,n} with , then (A+A)∩(A−A)contains a term of {ak }. The lower bound for |A| is optimal. Beyond these, we also prove that if n≥3is an integer and A is a subset of {0,1,…,n} with , then (A+A)∩(A−A)contains a power of 2. Furthermore, cannot be improved.