Novel observations of midge and mosquito larval population dynamics in leaves of the northern pitcher plant,Sarracenia purpurea L.

The invertebrate communities in Sarracenia purpurea were characterized by surveying the contents of 474 leaves from six pitcher plant populations in the eastern United States. More than 8200 invertebrate specimens, both living and dead, were recovered. Midge and mosquito larvae comprised 7907 (96%) of the specimens, with a mean of 16.9 dipteran larvae per leaf. Although midge larvae were present at all collection sites, mosquito larvae were absent from two of the sites. In the latter sites, the number of midge larvae per leaf was greater. This report documents for the first time that there is no statistical difference between the average number of Diptera larvae per leaf for sites that contain both midge and mosquito larvae compared to sites that contain only midge larvae. It appears that pitcher plants maintain an average number of larvae per leaf based on a number of interacting factors which we do not fully understand. This investigation documents that in the absence of mosquito larvae, more midge larvae are found per leaf per leaf than would be predicted based on data from sites that contain both larval taxa.     

Biodegradable Monocrystalline Silicon Photovoltaic Microcells as Power Supplies for Transient Biomedical Implants

Bioresorbable electronic materials serve as foundations for implantable devices that provide active diagnostic or therapeutic function over a timeframe matched to a biological process, and then disappear within the body to avoid secondary surgical extraction. Approaches to power supply in these physically transient systems are critically important. This paper describes a fully biodegradable, monocrystalline silicon photovoltaic (PV) platform based on microscale cells (microcells) designed to operate at wavelengths with long penetration depths in biological tissues (red and near infrared wavelengths), such that external illumination can provide realistic levels of power. Systematic characterization and theoretical simulations of operation under porcine skin and fat establish a foundational understanding of these systems and their scalability. In vivo studies of a representative platform capable of generating ≈60 µW of electrical power under 4 mm of porcine skin and fat illustrate an ability to operate blue light‐emitting diodes (LEDs) as subdermal implants in rats for 3 d. Here, the PV system fully resorbs after 4 months. Histological analysis reveals that the degradation process introduces no inflammatory responses in the surrounding tissues. The results suggest the potential for using silicon photovoltaic microcells as bioresorbable power supplies for various transient biomedical implants.     

The Relationship between Gene Network Structure and Expression Variation among Individuals and Species

Variation among individuals is a prerequisite of evolution by natural selection. As such, identifying the origins of variation is a fundamental goal of biology. We investigated the link between gene interactions and variation in gene expression among individuals and species using the mammalian limb as a model system. We first built interaction networks for key genes regulating early (outgrowth; E9.5–11) and late (expansion and elongation; E11-13) limb development in mouse. This resulted in an Early (ESN) and Late (LSN) Stage Network. Computational perturbations of these networks suggest that the ESN is more robust. We then quantified levels of the same key genes among mouse individuals and found that they vary less at earlier limb stages and that variation in gene expression is heritable. Finally, we quantified variation in gene expression levels among four mammals with divergent limbs (bat, opossum, mouse and pig) and found that levels vary less among species at earlier limb stages. We also found that variation in gene expression levels among individuals and species are correlated for earlier and later limb development. In conclusion, results are consistent with the robustness of the ESN buffering among-individual variation in gene expression levels early in mammalian limb development, and constraining the evolution of early limb development among mammalian species.     

Design and Validation of a Periodic Leg Movement Detector

Periodic Limb Movements (PLMs) are episodic, involuntary movements caused by fairly specific muscle contractions that occur during sleep and can be scored during nocturnal polysomnography (NPSG). Because leg movements (LM) may be accompanied by an arousal or sleep fragmentation, a high PLM index (i.e. average number of PLMs per hour) may have an effect on an individual’s overall health and wellbeing. This study presents the design and validation of the Stanford PLM automatic detector (S-PLMAD), a robust, automated leg movement detector to score PLM. NPSG studies from adult participants of the Wisconsin Sleep Cohort (WSC, n = 1,073, 2000–2004) and successive Stanford Sleep Cohort (SSC) patients (n = 760, 1999–2007) undergoing baseline NPSG were used in the design and validation of this study. The scoring algorithm of the S-PLMAD was initially based on the 2007 American Association of Sleep Medicine clinical scoring rules. It was first tested against other published algorithms using manually scored LM in the WSC. Rules were then modified to accommodate baseline noise and electrocardiography interference and to better exclude LM adjacent to respiratory events. The S-PLMAD incorporates adaptive noise cancelling of cardiac interference and noise-floor adjustable detection thresholds, removes LM secondary to sleep disordered breathing within 5 sec of respiratory events, and is robust to transient artifacts. Furthermore, it provides PLM indices for sleep (PLMS) and wake plus periodicity index and other metrics. To validate the final S-PLMAD, experts visually scored 78 studies in normal sleepers and patients with restless legs syndrome, sleep disordered breathing, rapid eye movement sleep behavior disorder, narcolepsy-cataplexy, insomnia, and delayed sleep phase syndrome. PLM indices were highly correlated between expert, visually scored PLMS and automatic scorings (r² = 0.94 in WSC and r² = 0.94 in SSC). In conclusion, The S-PLMAD is a robust and high throughput PLM detector that functions well in controls and sleep disorder patients.     

Cyanoseq: A database of cyanobacterial 16S rRNA gene sequences with curated taxonomy

Cyanobacteria are photosynthetic bacteria that occupy various habitats across the globe, playing critical roles in many of Earth's biogeochemical cycles both in both aquatic and terrestrial systems. Despite their well-known significance, their taxonomy remains problematic and is the subject of much research. Taxonomic issues of Cyanobacteria have consequently led to inaccurate curation within known reference databases, ultimately leading to problematic taxonomic assignment during diversity studies. Recent advances in sequencing technologies have increased our ability to characterize and understand microbial communities, leading to the generation of thousands of sequences that require taxonomic assignment. We herein propose CyanoSeq ( https://zenodo.org/record/7569105 ), a database of cyanobacterial 16S rRNA gene sequences with curated taxonomy. The taxonomy of CyanoSeq is based on the current state of cyanobacterial taxonomy, with ranks from the domain to genus level. Files are provided for use with common naive Bayes taxonomic classifiers, such as those included in DADA2 or the QIIME2 platform. Additionally, FASTA files are provided for creation of de novo phylogenetic trees with (near) full-length 16S rRNA gene sequences to determine the phylogenetic relationship of cyanobacterial strains and/or ASV/OTUs. The database currently consists of 5410 cyanobacterial 16S rRNA gene sequences along with 123 Chloroplast, Bacterial, and Vampirovibrionia (formally Melainabacteria) sequences.     

HEDONIC SCALES ARE A BETTER PREDICTOR THAN JUST-ABOUT-RIGHT SCALES OF OPTIMAL SWEETNESS IN LEMONADE1

A comparison of hedonic scales and just-about-right (JAR) scales is needed because data in previous studies using JAR scales suggest that predicted optimum levels of ingredients often are not the same as the levels in products that currently are sold successfully. Thus, in this research, consumers tested lemonade varying in sugar concentration from 6% to 14%, using (1) a JAR scale formed by boxes or a line and (2) a hedonic box-type scale. Predicted “optimum” levels of sweetness for the lemonade and differences in liking for the formulations were determined. The JAR line and box scales gave similar predicted optimal results (9.2% and 9.4% sucrose, respectively), which were significantly lower than the hedonic scale results (10.3% sucrose). In a preference test, consumers significantly preferred the 10.3% sugar lemonade over the 9.3% concentration, indicating that, based on paired preference testing, the hedonic scale resulted in better prediction of optimal sweetness than the JAR scale.     

Stage-specific nitrogen metabolism in developing carrot somatic embryos

The physiology of individual somatic embryo developmental stages otDaucus carota L. was examined by in vivo nuclear magnetic resonance (NMR) spectroscopy, amino acid analysis and ¹⁴C-labeling. ¹⁵N NMR spectroscopy was used to examine the uptake and incorporation of ¹⁵N isotopically labeled inorganic nitrogen sources. NMR spectra of proembryogenic masses (PEMs) contained resonances for histidine, amino sugars, glutamine, arginine, urea, alanine. α-amino nitrogen, serine, aliphatic amines and several unknowns. Similar resonances were found in various embryo developmental stages. However, resonances for arginine and aliphatic amines peaked during globular and torpedo stages and substantially decreased in germinating stage embryos. The dominant resonances observed in non-embryogenic cells and germinating embryos were glutamine and α-amino nitrogen. Amino acid analysis of the various embryo stages showed that glutamate, glutamine and arginine were the major contributors to the soluble amino acid profiles. During development, glutamate and glutamine continued to increase in concentration whereas arginine and its related metabolites (i.e. ornithine and y-aminobutyric acid [GABA]) were biphasic; increasing in globular and torpedo stage embryos and decreasing in germinating embryos. Carbon-14 labeling indicated that labeled glutamine pools in non-embryogenic and germinating embryos were greatest compared to other embryo stages, whereas labeled GABA pools were greatest in globular and torpedo stage embryos. Taken together, these data indicate that the physiology of each embryo developmental stage is distinct. They also suggest that during somatic embryo development, a switch takes place in metabolism whereby the glutamine synthetase/glutamate synthase (GS/GOGAT) pathway is predominant in non-embryogenic cells and germinating stage embryos. Furthermore, during early to mid-embryo development (PEMs, globular and torpedo stage embryos), metabolism utilizing the omithine cycle is enhanced and predominant.     

Drift and upstream movement of invertebrates in a springbrook community ecosystem

Structure, drift, and upstream movement of populations of benthic macroinvertebrates, in particular Synurella dentata Hubricht and Lirceus fontinalis Raf., were examined within a temperate spring ecosystem. Chemical and physical aspects of the springbrook were also investigated and life histories of the gammarids and asellids noted.Chemically and physically the spring proved both constant and predictable, much more so than other lotic systems.Species diversity was low from November through February and increased in March, April, and May. Equitability followed the same trends as species diversity. Both indices were most affected by large fluctuations in the populations of aquatic insects.Significant changes in the numbers of amphipods, isopods, and total macroinvertebrates was evident over a seven month period. Males were present in the isopod population year-round, but only from November to January in the amphipod population. Breeding by the isopods occurred throughout the year and peaked during winter. Amphipods copulated only in the late fall and early winter.Significant diel peaks in the amphipod, isopod, and total invertebrate drift negatively correlated with light intensity levels. Amphipods and isopods did not exhibit any preferential upstream movement during either the day or night; however, total macroinvertebrate upstream movement was greater at night. The total number of invertebrates moving upstream were lower than values reported from other lotic environments.