Description of pereiopod setae of scyllarid lobsters, Scyllarides aequinoctialis, Scyllarides latus, and Scyllarides nodifer, with observations on the feeding during consumption of bivalves and gastropods

The morphological and behavioral aspects of slipper lobster (Scyllaridae) feeding have remained largely unexplored. Using scanning electron microscopy, the gross morphological structure of all segments of the pereiopods were described for three species of scyllarid lobsters. Five types of setae within three broad categories were found: simple (long and miniature), cuspidate (robust and conate), and teasel (a type of serrulate setae). Setae were arranged in a highly-organized, row-like pattern on the ventral and dorsal surfaces. Cuspidate setae were found on all surfaces of all segments. Simple setae were found only on the dactyl, whereas teazel setae were concentrated on the lateral-most edge of the alate carina on the merus in only one species [Scyllarides aequinoctialis (Lund, 1793)]; this species also differed from the other two [Scyllarides nodifer (Stimpson, 1866), Scyllarides latus (Latreille, 1803)] in setal patterning. All examined slipper lobsters differed in setal types and patterns from nephropid and palinurid lobsters, likely due to the more rigorous use of their pereiopods in accessing food. Feeding sequences of two of the slipper lobster species were videotaped and analyzed, and demonstrated a complex set of behaviors involving contact chemoreception by the antennules as part of an initial assessment of the food item, followed by extensive manipulation, probing, and eventual wedging behavior by the pereiopods as previously described for Scyllarides. Use of the antennules for food assessment and heavy reliance on the pereiopods, rather than the mouthparts, for food handling contrasts with nephropid and palinurid lobsters.https://doi.org/10.5343/bms.2017.1125Published versio

Usefulness of nabilone as an antiemetic in persistent vomiting due to refractory gastrointestinal disorders

Nabilone, a synthetic analogue of delta-9-Tetrahydrocannabinol, is an agonist of cannabinoid receptors (CB-1 and CB-2) approved to treat chemotherapy-induced vomiting refractory to antiemetics. Its use in patients with refractory vomiting due to gastrointestinal dysmotility (GID) has not been reported. Our study aims are to assess nabilone usefulness and side-effects in patients with refractory vomiting due to GID. Patients prescribed nabilone at St. Mark's intestinal rehabilitation unit (January 2017 to September 2022) due to GID vomiting have been retrospectively reviewed. Descriptive analysis has been done. Variables measured: age, sex, comorbidities, antiemetics/prokinetics, enteral or parenteral nutrition, nabilone prescription, subjective symptom improvement and side-effects. Seven patients received nabilone. 5/7 (72%) were females. Median age:25 years (23-37). 3/7 (43%) had gastroparesis (1/3 related to postural orthostatic tachycardia syndrome -POTS- , 1/3 to Ehlers-Danlos' Syndrome, POTS, Crohn's Disease and adrenal insufficiency -AI- and 1/3 to sinus node ablation and AI), 2/7 (29%) had gastroparesis and intestinal dysmotility (1/2 related to POTS and 1/2 related to EDS and other connective tissue diseases) and 2/7 (29%) had intestinal dysmotility (1/2 because of polyglucosan body visceral myopathy and 1/2 to intestinal surgery). All patients had received antiemetics or prokinetics before (median of 5 drugs; 2-11). 1/7 (14%) received enteral supplements, 5/7 (72%) enteral nutrition through enteral tubes and 4/7 (57%) parenteral nutrition. 5/7 (72%) patients received 1mg of nabilone bd orally, 1/7 (14%) 2 mg bd through jejunostomy and 1/7 (14%) started nabilone at 2 mg bd orally, but had to be switched to 1 mg bd because of side-effects. The median treatment's duration was 9 days (7-35). Regarding the efficacy of nabilone, 3/7 (43%) had symptomatic improvement. In terms of side-effects 4/7 (57%) patients reported some incidence under the treatment such as headache, light-headedness, drowsiness, dizziness or hallucinations. Patients with refractory GID vomiting despite multiple anti-sickness are difficult to treat. Nabilone improved symptoms in almost half of the patients although adverse effects appeared in more than 50%. Doses higher than 1 mg bd po did not show benefit. Although our study has important limitations, nabilone might be a temporary measure in these patients. Side-effects should be taken into consideration

Radiative decay of a massive particle and the non-thermal process in primordial nucleosynthesis

We consider the effects on big bang nucleosynthesis (BBN) of the radiative decay of a long-lived massive particle. If high-energy photons are emitted after the BBN epoch ($t \sim 1 - 10^3$ sec), they may change the abundances of the light elements through photodissociation processes, which may result in a significant discrepancy between standard BBN and observation. Taking into account recent observational and theoretical developments in this field, we revise our previous study constraining the abundance of the radiatively-decaying particles. In particular, on the theoretical side, it was recently claimed that the non-thermal production of $^6$Li, which is caused by the photodissociation of \hefour, most severely constrains the abundance of the radiatively-decaying particle. We will see, however, it is premature to emphasize the importance of the non-thermal production of $^6$Li because (i) the theoretical computation of the $^6$Li abundance has large uncertainty due to the lack of the precise understanding of the $^6$Li production cross section, and (ii) the observational data of $^6$Li abundance has large errors.Comment: 15 pages, using REVTeX and 3 postscript figure

Radio-Frequency Spectroscopy

Contains reports on four research projects

Radio-Frequency Spectroscopy

Contains reports on four research projects

Microwave Physics

Contains reports on five research projects

Microwave Physics

Contains reports on six research projects

Radio-Frequency Spectroscopy

Contains reports on four research projects

Late Replicating Domains Are Highly Recombining in Females but Have Low Male Recombination Rates: Implications for Isochore Evolution

In mammals sequences that are either late replicating or highly recombining have high rates of evolution at putatively neutral sites. As early replicating domains and highly recombining domains both tend to be GC rich we a priori expect these two variables to covary. If so, the relative contribution of either of these variables to the local neutral substitution rate might have been wrongly estimated owing to covariance with the other. Against our expectations, we find that sex-averaged recombination rates show little or no correlation with replication timing, suggesting that they are independent determinants of substitution rates. However, this result masks significant sex-specific complexity: late replicating domains tend to have high recombination rates in females but low recombination rates in males. That these trends are antagonistic explains why sex-averaged recombination is not correlated with replication timing. This unexpected result has several important implications. First, although both male and female recombination rates covary significantly with intronic substitution rates, the magnitude of this correlation is moderately underestimated for male recombination and slightly overestimated for female recombination, owing to covariance with replicating timing. Second, the result could explain why male recombination is strongly correlated with GC content but female recombination is not. If to explain the correlation between GC content and replication timing we suppose that late replication forces reduced GC content, then GC promotion by biased gene conversion during female recombination is partly countered by the antagonistic effect of later replicating sequence tending increase AT content. Indeed, the strength of the correlation between female recombination rate and local GC content is more than doubled by control for replication timing. Our results underpin the need to consider sex-specific recombination rates and potential covariates in analysis of GC content and rates of evolution

Black Girls Speak STEM: Counterstories of Informal and Formal Learning Experiences

This study presents the interpretations and perceptions of Black girls who participated in I AM STEM – a community-based informal science, technology, engineering, and mathematics (STEM) program. Using narrative inquiry, participants generated detailed accounts of their informal and formal STEM learning experiences. Critical race methodology informed this research to portray the dynamic and complex experiences of girls of color, whose stories have historically been silenced and misrepresented. The data sources for this qualitative study included individual interviews, student reflection journals, samples of student work, and researcher memos, which were triangulated to produce six robust counterstories. Excerpts of the counterstories are presented in this article. The major findings of this research revealed that I AM STEM ignited an interest in STEM learning through field trips and direct engagement in scientific phenomena that allowed the girls to become agentic in continuing their engagement in STEM activities throughout the year. This call to awaken the voices of Black girls to speak casts light on their experiences and challenges as STEM learners ⎯ from their perspectives. The findings confirm that when credence and counterspaces are given to Black girls, they are poised to reveal their luster toward STEM learning. This study provided a space for Black girls to reflect on their STEM learning experiences, formulate new understandings, and make connections between the informal and formal learning environments within the context of their everyday lives, thus offering a more holistic approach to STEM learning that occurs across settings and over a lifetime