Mirror Symmetry and Other Miracles in Superstring Theory

The dominance of string theory in the research landscape of quantum gravity physics (despite any direct experimental evidence) can, I think, be justified in a variety of ways. Here I focus on an argument from mathematical fertility, broadly similar to Hilary Putnam's 'no miracles argument' that, I argue, many string theorists in fact espouse. String theory leads to many surprising, useful, and well-confirmed mathematical 'predictions' - here I focus on mirror symmetry. These predictions are made on the basis of general physical principles entering into string theory. The success of the mathematical predictions are then seen as evidence for framework that generated them. I attempt to defend this argument, but there are nonetheless some serious objections to be faced. These objections can only be evaded at a high (philosophical) price.Comment: For submission to a Foundations of Physics special issue on "Forty Years Of String Theory: Reflecting On the Foundations" (edited by G. `t Hooft, E. Verlinde, D. Dieks and S. de Haro)

What are Friends For? The Impact of Friendship on Communicative Efficiency and Cortisol Response during Collaborative Problem Solving Among Younger and Older Women

Conversation is a skilled activity that depends on cognitive and social processes, both of which develop through adulthood. We examined the effects of age and partner familiarity on communicative efficiency and cortisol reactivity. Younger and older women interacted with familiar or unfamiliar partners in a dyadic collaborative conversation task (N = 8 in each group). Regardless of age, referential expressions among familiar and unfamiliar partners became more efficient over time, and cortisol concentrations were lower for speakers interacting with familiar partners. These findings suggest that communicative effectiveness is largely preserved with age, as is the stress-buffering effect of a familiar partner

High-throughput amplicon sequencing datasets of coastal sediments from three locations of the Gulf of Mexico, USA

We present high-throughput amplicon sequence (HTS) datasets of the purified microbial metacommunity DNA of coastal surface sediments from Portersville Bay (PVB) (n = 3), Bayou La Batre (BLB) (n = 3), and Mobile Bay (MOB) (n = 3) of the U.S. Gulf of Mexico (U.S. Gulf Coast). The PVB samples were collected from the oyster aquaculture Shellevator™ system; the BLB samples were from locations on the shoreline adjacent to wild oysters attached to rocks and likely polluted from sewage and possibly chemical contamination from boats, shipyards, and seafood processing facilities; and MOB samples were adjacent to aquaculture oysters in bottom cages. The amplicons of the V4 hypervariable segment of the 16S rRNA gene from each sample were sequenced on an Illumina MiSeq to generate these HTS datasets. The raw sequences were quality-checked, demultiplexed into FASTQ files, denoised using DADA2, and subsampled. Then, the FASTA formatted sequences were assigned the taxonomic ids to amplicon sequence variants (ASVs) against the silva-138–99-nb-classifier using the Quantitative Insights Into Microbial Ecology (QIIME2 v2022.2). The applicability of the HTS datasets was confirmed by microbial taxa analysis at the phylum level using the ''qiime taxa collapse'' command. All HTS datasets are available through the BioSample Submission Portal under the BioProject ID PRJNA876773 (https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA876773)

Dissemination of imidacloprid through dairy cattle manure and its effect on the biological control agent, Spalangia endius (Hymenoptera: Pteromalidae), and a filth fly host, Musca domestica (Diptera: Muscidae)

Filth flies, including house flies, Musca domestica L. (Diptera: Muscidae), develop in animal manure. Adult house flies often are controlled with pesticides such as imidacloprid. How imidacloprid disseminates and persists after it contaminates manure was measured at a dairy farm. A week after application of imidacloprid via fly bait to cattle manure, a mean of approximately 4 ppm of imidacloprid, and as high as 15 ppm, was quantifiable up to 12 cm from the application site, but not farther. Laboratory experiments addressed the impact of 15 ppm of imidacloprid in manure on egg-to-adult development of house flies and on the biological control ability of a house fly pupal parasitoid, Spalangia endius Walker (Hymenoptera: Pteromalidae). In uncontaminated manure, 93% of eggs developed to adults, versus 7% in contaminated manure. In the parasitoid experiment, fly pupae were placed in contaminated or uncontaminated manure with or without S. endius. In the absence of S. endius, nearly 100% of flies emerged, with or without imidacloprid. In the presence of S. endius, only 11% of flies emerged from uncontaminated manure, versus 36% from contaminated manure; and parasitoids emerged from 82% of hosts in uncontaminated manure versus 53% in contaminated manure. These results suggest that realistic concentrations of imidacloprid in filth fly breeding habitat may interfere with house flies developing to the pupal stage, but also with parasitoids locating and utilizing house flies. However, after 1 wk, the effects on parasitoids will be low 12 cm beyond where bait was applied

Theoretical influence of female mating status and remating propensity on male sperm allocation patterns

Engqvist L, Reinhold K. Theoretical influence of female mating status and remating propensity on male sperm allocation patterns. JOURNAL OF EVOLUTIONARY BIOLOGY. 2006;19(5):1448-1458.Theoretical models predict that males should allocate more sperm in matings where the immediate risk of sperm competition is high. It has therefore often been argued that males should invest less sperm in matings with virgin females compared with matings with already mated females. However, with relatively polyandrous females, high sperm competition risk will covary with high sperm competition intensity leading to more unpredictable conditions, as high competition intensity should favour smaller ejaculates. With the use of a genetic algorithm, we found that males should allocate more sperm in matings with virgin females when female mating frequency is relatively high, whereas low remating rates will select for higher effort in matings with nonvirgin females. At higher remating rates, first male sperm precedence favours larger ejaculates in matings with virgin females and second male precedence favours the reverse. These results shed some light on several findings that have been difficult to explain adaptively by the hitherto developed theory on sperm allocation

Prevalência de Salmonella sp em suínos abatidos em frígoríficos do Rio Grande do Sul Prevalence of Salmonella sp. carrier pigs in slaughterhouses of Rio Grande do Sul, Brazil

Este estudo foi realizado com o objetivo de determinar a prevalência de Salmonella sp em suínos abatidos em frigoríficos sob inspeção federal no Rio Grande do Sul. Amostras de fezes e linfonodos foram coletadas em três diferentes frigoríficos no Estado. A partir da análise microbiológica das amostras de 300 animais, encontrou-se uma prevalência de Salmonella sp de 55,66%, com 17,6% de isolamentos a partir dos linfonodos, 18,3% das fezes e 19,6% em ambos os materiais. Foram identificados 26 sorovares diferentes em 226 isolados de Salmonella sp. Os sorovares mais prevalentes foram: Typhimurium (24,3%), Agona (19,9%), Derby (13,2%) e Bredeney (12%). Estes resultados indicam a necessidade de implementar programas de controle com o objetivo de diminuir a prevalência de animais portadores ao abate.<br>This study aimed to determine the prevalence of Salmonella positive pigs at slaughterhouses under federal inspection in Rio Grande do Sul, Brazil. Samples of feces and lymph nodes of 300 animals were collected in three different slaughterhouses, and submitted to bacteriological analysis. The prevalence of Salmonella carrier animals was 55.66%, being 17.6% of the animals Salmonella positive in lymph nodes, 18.3% in feces and 19.6% in both materials. Twenty-six different serovars were identified among 226 Salmonella isolates. The most prevalent serovars were: Typhimurium (24.3%), Agona (19.9%), Derby (13.2%) e Bredeney (12%). These results point out the need of control programs to reduce the prevalence of carrier pigs at slaughter