An analysis of the association between various synaptic parameters during cortical development

Summary Stellate cells in the rabbit adenohypophysis were observed electron microscopically under normal and experimental conditions such as lactation, thyroidectomy, adrenalectomy, or castration.In control animals stellate cells had a scanty cytoplasm surrounding the nucleus and possessed slender processes extending between granulated cells. The processes were interconnected by desmosomes to form a meshwork. In the cytoplasm, abundant microfilaments were present as well as ill-developed ordinary cell organelles, but secretory granules were absent.In the adenohypophysis of experimental groups, in which the granulated cells underwent characteristic changes, stellate cells also showed remarkable morphological alterations which were similar in all groups. In general, they became hypertrophied, and contained a well-developed Golgi apparatus and rough-surfaced endoplasmic reticulum. Lysosomes or lipid droplets were frequently encountered. Between adjacent stellate cells, intercellular canals were markedly developed and many microvilli were noticed.Based on the above data, it is suggested that the stellate cells are not only sustentacular elements, but play an important role in the function of the adenohypophysis, such as the supply of materials to granulated cells or the disposal of waste products.This investigation was supported in part by the Ministry of Education, Science and Culture, Japan     

Wildflower plantings promote blue orchard bee,Osmia lignaria (Hymenoptera: Megachilidae), reproduction in California almond orchards

Concerns over the availability of honeybees (Apis mellifera L.) to meet pollination demands have elicited interest in alternative pollinators to mitigate pressures on the commercial beekeeping industry. The blue orchard bee, Osmia lignaria (Say), is a commercially available native bee that can be employed as a copollinator with, or alternative pollinator to, honeybees in orchards. To date, their successful implementation in agriculture has been limited by poor recovery of bee progeny for use during the next spring. This lack of reproductive success may be tied to an inadequate diversity and abundance of alternative floral resources during the foraging period. Managed, supplementary wildflower plantings may promote O. lignaria reproduction in California almond orchards. Three wildflower plantings were installed and maintained along orchard edges to supplement bee forage. Plantings were seeded with native wildflower species that overlapped with and extended beyond almond bloom. We measured bee visitation to planted wildflowers, bee reproduction, and progeny outcomes across orchard blocks at variable distances from wildflower plantings during 2015 and 2016. Pollen provision composition was also determined to confirm O. lignaria wildflower pollen use. Osmia lignaria were frequently observed visiting wildflower plantings during, and after, almond bloom. Most O. lignaria nesting occurred at orchard edges. The greatest recovery of progeny occurred along the orchard edges having the closest proximity (80 m) to managed wildflower plantings versus edges farther away. After almond bloom, O. lignaria nesting closest to the wildflower plantings collected 72% of their pollen from Phacelia spp., which supplied 96% of the managed floral area. Phacelia spp. pollen collection declined with distance from the plantings, but still reached 17% 800 m into the orchard. This study highlights the importance of landscape context and proximity to supplementary floral resources in promoting the propagation of solitary bees as alternative managed pollinators in commercial agriculture.     

A total crapshoot? Evaluating bioinformatic decisions in animal diet metabarcoding analyses

Metabarcoding studies provide a powerful approach to estimate the diversity and abundance of organisms in mixed communities in nature. While strategies exist for optimizing sample and sequence library preparation, best practices for bioinformatic processing of amplicon sequence data are lacking in animal diet studies. Here we evaluate how decisions made in core bioinformatic processes, including sequence filtering, database design, and classification, can influence animal metabarcoding results. We show that denoising methods have lower error rates compared to traditional clustering methods, although these differences are largely mitigated by removing low‐abundance sequence variants. We also found that available reference datasets from GenBank and BOLD for the animal marker gene cytochrome oxidase I (COI) can be complementary, and we discuss methods to improve existing databases to include versioned releases. Taxonomic classification methods can dramatically affect results. For example, the commonly used Barcode of Life Database (BOLD) Classification API assigned fewer names to samples from order through species levels using both a mock community and bat guano samples compared to all other classifiers (vsearch‐SINTAX and q2‐feature‐classifier's BLAST + LCA, VSEARCH + LCA, and Naive Bayes classifiers). The lack of consensus on bioinformatics best practices limits comparisons among studies and may introduce biases. Our work suggests that biological mock communities offer a useful standard to evaluate the myriad computational decisions impacting animal metabarcoding accuracy. Further, these comparisons highlight the need for continual evaluations as new tools are adopted to ensure that the inferences drawn reflect meaningful biology instead of digital artifacts.     

Rates and Characteristics of Sleep Paralysis in the General Population of Denmark and Egypt

In the current research we report data from two studies that examined rates and characteristics of sleep paralysis (SP) in the general population of Denmark and Egypt. In Study I, individuals from Denmark and Egypt did not differ in age whereas there were more males in the Egyptian sample (47 vs. 64 %); in Study II, individuals from Denmark and Egypt were comparable in terms of age and gender distribution. In Study I we found that significantly fewer individuals had experienced SP in Denmark [25 % (56/223)] than in Egypt [44 % (207/470)] p < .001. In Study II we found that individuals who had experienced at least one lifetime episode of SP from Denmark (n = 58) as compared to those from Egypt (n = 143) reported significantly fewer SP episodes in a lifetime relative to SP experiencers from Egypt (M = 6.0 vs. M = 19.4, p < .001). SP in the Egyptian sample was characterized by high rates of SP (as compared to in Denmark), frequent occurrences (three times that in the Denmark sample), prolonged immobility during SP, and great fear of dying from the experience. In addition, in Egypt, believing SP to be precipitated by the supernatural was associated with fear of the experience and longer SP immobility. Findings are discussed in the context of cultural elaboration and salience theories of SP.     

PMR5, an acetylation protein at the intersection of pectin biosynthesis and defense against fungal pathogens

Powdery mildew (Golovinomyces cichoracearum), one of the most prolific obligate biotrophic fungal pathogens worldwide, infects its host by penetrating the plant cell wall without activating the plant's innate immune system. The Arabidopsis mutant powdery mildew resistant 5 (pmr5) carries a mutation in a putative pectin acetyltransferase gene that confers enhanced resistance to powdery mildew. Here, we show that heterologously expressed PMR5 protein transfers acetyl groups from [¹⁴C]‐acetyl‐CoA to oligogalacturonides. Through site‐directed mutagenesis, we show that three amino acids within a highly conserved esterase domain in putative PMR5 orthologs are necessary for PMR5 function. A suppressor screen of mutagenized pmr5 seed selecting for increased powdery mildew susceptibility identified two previously characterized genes affecting the acetylation of plant cell wall polysaccharides, RWA2 and TBR. The rwa2 and tbr mutants also suppress powdery mildew disease resistance in pmr6, a mutant defective in a putative pectate lyase gene. Cell wall analysis of pmr5 and pmr6, and their rwa2 and tbr suppressor mutants, demonstrates minor shifts in cellulose and pectin composition. In direct contrast to their increased powdery mildew resistance, both pmr5 and pmr6 plants are highly susceptibile to multiple strains of the generalist necrotroph Botrytis cinerea, and have decreased camalexin production upon infection with B. cinerea. These results illustrate that cell wall composition is intimately connected to fungal disease resistance and outline a potential route for engineering powdery mildew resistance into susceptible crop species.     

Can Healthy Sleep Improve Long‐Term Bariatric Surgery Outcomes? Results of a Pilot Study and Call for Further Research

Healthy sleep is associated with lower body weight and could improve and sustain weight loss following bariatric surgery. To support this premise, preliminary data on the relation between sleep duration and quality and long‐term weight change in a subsample of participants from the Longitudinal Assessment of Bariatric Surgery are presented. Results indicate a relation between sleep duration and BMI and percent weight loss 9 years after surgery. Additionally, sleep quality explained 25% of the variance in weight change between 6‐ and 9‐year follow‐up visits. These data from a small exploratory study, in combination with the known effects of sleep on energy balance, suggest that sleep may play an important role in both immediate and sustained weight loss following bariatric surgery. Herein, a model of the proposed bidirectional relation between sleep and weight loss is presented as well as a call for systematic investigations of the influence of sleep on long‐term weight management following bariatric surgery.     

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS): high-resolution physical and transcript map of the candidate region in chromosome region 13q11

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS or SACS) is a neurodegenerative disease frequent in northeastern Québec. In a previous study, we localized the disease gene to chromosome region 13q11 by identifying excess sharing of a marker allele in patients followed by linkage analysis and haplotyping. To create a detailed physical map of this region, we screened CEPH mega-YACs with 41 chromosome 13 sequence-tagged-sites (STSs) known to map to 13q11-q12. The YAC contig, composed of 27 clones, extends on the genetic map from D13S175 to D13S221, an estimated distance of at least 19.3 cM. A high-resolution BAC and PAC map that includes the ARSACS critical region flanked by D13S1275 and D13S292 was constructed. These YAC and BAC/PAC maps allowed the accurate placement of 29 genes and ESTs previously mapped to the proximal region of chromosome 13q. We confirmed the position of two candidate genes within the critical region and mapped the other 27 genes and ESTs to nearby intervals. Six BAC/PAC clones form a contig between D13S232 and D13S787 for sequencing within the ARSACS critical region.     

Structure-function analysis of Escherichia coli DNA helicase I reveals non-overlapping transesterase and helicase domains

TraI (DNA helicase I) is an Escherichia coli F plasmid-encoded protein required for bacterial conjugative DNA transfer. The protein is a sequence-specific DNA transesterase that provides the site- and strand-specific nick required to initiate DNA strand transfer and a 5' to 3' DNA helicase that unwinds the F plasmid to provide the single-stranded DNA that is transferred from donor to recipient. Sequence comparisons with other transesterases and helicases suggest that these activities reside in the N- and C-terminal regions of TraI, respectively. Computer-assisted secondary structure probability analysis identified a potential interdomain region spanning residues 304-309. Proteins encoded by segments of traI, whose N or C terminus either flanked or coincided with this region, were purified and assessed for catalytic activity. Amino acids 1-306 contain the transesterase activity, whereas amino acids 309-1504 contain the helicase activity. The C-terminal 252 amino acids of the 1756-amino acid TraI protein are not required for either helicase or transesterase activity. Protein and nucleic acid sequence similarity searches indicate that the occurrence of both transesterase- and helicase-associated motifs in a conjugative DNA transfer initiator protein is rare. Only two examples (other than R100 plasmid TraI) were found: R388 plasmid TrwC and R46 plasmid (pKM101) TraH, belonging to the IncW and IncN groups of broad host range conjugative plasmids, respectively. The most significant structural difference between these proteins and TraI is that TraI contains an additional region of approximately 650 residues between the transesterase domain and the helicase-associated motifs. This region is required for helicase activity.