Automated extraction of bank angles from bird‐borne video footage using open‐source software

The use of miniaturized video cameras to study the at‐sea behavior of flying seabirds has increased in recent years. These cameras allow researchers to record several behaviors that were not previously possible to observe. However, video recorders produce large amounts of data and videos can often be time‐consuming to analyze. We present a new technique using open‐source software to extract bank angles from bird‐borne video footage. Bank angle is a key facet of dynamic soaring, which allows albatrosses and petrels to efficiently search vast areas of ocean for food. Miniaturized video cameras were deployed on 28 Wandering Albatrosses (Diomedea exulans) on Marion Island (one of the two Prince Edward Islands) from 2016 to 2018. The OpenCV library for the Python programming language was used to extract the angle of the horizon relative to the bird’s body (= bank angle) from footage when the birds were flying using a series of steps focused on edge detection. The extracted angles were not significantly different from angles measured manually by three independent observers, thus being a valid method to measure bank angles. Image quality, high wind speeds, and sunlight all influenced the accuracy of angle estimates, but post‐processing eliminated most of these errors. Birds flew most often with cross‐winds (58%) and tailwinds (39%), resulting in skewed distributions of bank angles when birds turned into the wind more often. Higher wind speeds resulted in extreme bank angles (maximum observed was 94°). We present a novel method for measuring postural data from seabirds that can be used to describe the fine‐scale movements of the dynamic‐soaring cycle. Birds appeared to alter their bank angle in response to varying wind conditions to counter wind drift associated with the prevailing westerly winds in the Southern Ocean. These data, in combination with fine‐scale positional data, may lead to new insights into dynamic‐soaring flight.     

The uptake of liposome-entraped 125I-labelled poly(vinylpyrrolidone) by rat jejunum in vitro

The uptake of free and liposome-entrapped ¹²⁵I-labelled poly(vinylpyrrolidone) was measured in an intestinal sac preparation from adult rats. An an equal concentration of ¹²⁵I-labelled poly(vinylpyrrolidone), the rate of uptake of the liposome-entrapped material was four times that of the free macromolecule.     

Structure and function of the head in flabelligerid polychaetes

The functional anatomy of the head of Flabelliderma commensalis is described and compared to other flabelligerid polychaetes. Prostomial parts include the dorsal lip, the palps, two pairs of nuchal organs, four eyes and the prostomial lobe and ridge. The eyes are inverse pigment cup types with the medial portions of the sensory cells expanded to form a clear lens-like body. Peristomial parts include the median and ventral lips, the branchial membrane and the branchiae. The derivation of the nephridiopore is unknown. The spiraled branchiae of Coppingeria and the gill books of Diplocirrus are newly described variations in branchial structure. The head is retractable in some species and the anterior setigers are modified to form a protective setal cage. Two methods are employed for feeding: one for host fecal pellets and the other for detrital materials. Chemoreception, respiration, feeding and cleaning rely on a complex pattern of ciliary currents.     

In vitro study of lipid metabolism in the mealworm larval fat body

Lipid metabolism in Tenebrio larval fat body has been studied in vitro. Lipid release required the presence of diluted hemolymph in the incubation medium. This time-dependent release of lipid was strongly stimulated in a dose-dependent manner by Tenebrio corpora cardiaca (CC) extracts or synthetic adipokinetic hormone (AKH I). Furthermore, some glycerol was released when larval fat body was incubated without hemolymph, and this phenomenon was also dose dependent for added CC extracts. Lipid synthesis was estimated in vitro by following the incorporation of radioactivity from [6-¹⁴C] glucose into fatty acids. Lipogenesis occurred in the absence of added carbohydrates in the medium, but it was stimulated by the addition of glucose, and especially trehalose (10 mg ml^?1). Intestinal insulin-like peptide (ILP) also stimulated in vitro lipogenesis in a dose-dependent fashion. We conclude that lipolytic and lipogenetic activities of larval mealworm fat body in vitro are effectively under hormonal control.     

Modulatory role of substance P on gonadotropin and prolactin secretion in the rabbit.

Substance P (SP) is present in large quantities in the brainstem and hypophysiotropic areas of the brain, but its roles in gonadotropin and prolactin secretion are controversial. The aim of this study was to measure luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin (PRL) release from the pituitary after either intracerebroventricular (ICV) injection or infusion of SP or its C- and N-terminal fragments in intact (INT) and ovariectomized (OVX) conscious rabbits. A single injection of SP into the 3rd cerebral ventricle (3CVT) in INT and OVX rabbits augmented plasma LH concentrations, especially when SP was applied during the initial phase of an LH peak. Injection of SP during the declining phase of LH release was not effective. Injection of SP into the 3CVT was followed by increased plasma PRL concentrations in OVX but not in INT rabbits. Both SP 1-11 and SP 1-7 failed to alter LH, FSH, and PRL secretion when the peptides were slowly infused into the 3CVT, although ICV infusion of SP 6-11 did cause a delayed increase in LH release. The results support a stimulatory role of SP on LH and prolactin release. The results further indicate that although the stimulatory effect of SP on LH is ovarian steroid-independent, in the absence of ovarian steroids, SP is stimulatory only during the rising phase of an LH pulse. A dual role of SP-ergic transmission in modulating LH secretion is discussed.     

Association of polymorphisms in the HLA-B region with extended haplotypes

Genomic probes from the HLA-B region of the major histocompatibility complex (MHC) were used to study the association of restriction fragment length polymorphisms (RFLPs) with various MHC alleles, complotypes, and extended haplotypes. The two DNA probes, M20A and R5A, were derived from previously cloned cosmids and are located 38 and 110 kilobases (kb) centromeric to HLa-B, respectively. Five different RFLP variants occuring in five different haplotypic combinations were detected within a panel of 40 homozygous-typing cells and cells from 21 families using Bst EII. In two informative families with HLA-B/DR recombinations the inheritance of the RFLP variants was consistent with their mapping between HLA-B and complotypes. The R5A/M20A haplotypic pattern 6.5 kb/3.0 kb (A) had a normal Caucasian frequency of approximately 0.43 and was found in all independent examples of the extended haplotypes [HLA-B8,SC01,DR3], [HLA-B18,F1C30, DR3], [HLa-Bw62,SC33,Dr4], [HLa-B44,SC30,Dr4], and [HLA-Bw47,FC91,0DR7]. The patterns of 6.9 kb/ 3.0 kb (B), 6.5 kb/4.7 kb (C), 1.45 kb/3.0 kb (D), and 6.9 kb/4.7 kb (E) had normal Caucasian frequencies of approximately 0.23, 0.15, 0.15, and 0.04 and were found on all independent examples of [HLA-B38,SC21, DR4], [HLA-Bw57,SC61,DR7], [HLA-B7,SC31,DR2], and [HLA-B44,FC31,DR7], respectively. Individual complotypes or HLA-B alleles which were markers of extended haplotypes showed variable associations. For example, HLA-B7 and the complotype SC31 were associated with all R5A/M20A RFLP haplotypes except haplotype E, although [HLA-B7,SC31,DR7] was associated exclusively with haplotype D. HLA-B27, not known to be part of an extended haplotype, was suprisingly exclusively associated with the 6.5 kb/4.7 kb or C haplotypic pattern in all five instances tested. These findings support the concept of regional conservation of DNA on independent examples of extended haplotypes. The results also further characterize these haplotypes.     

New genes in the MHC that encode proteins for antigen processing

Most cells process proteins into short peptides that are displayed on the cell surface bound to class I or class II proteins encoded by the major histocompatibility complex (MHC). These protein-peptide complexes can then be recognized by the circulating lymphocytes of the immune system. Several genes found recently in the MHC encode proteins with possible roles in the supply of peptides to class I molecules. The results imply that the peptides are produced in the cytoplasm by proteasomes and are translocated into the endoplasmic reticulum by 'peptide transporters' related to the multidrug resistance proteins. While there is little biochemical evidence to validate these ideas, Robert DeMars and Thomas Spies discuss here the arguments supporting this view. New data indicate that there may also be factors for class II peptide-processing hidden in the MHC.     

SB subregion of the human major histocompatibility complex: gene organization, allelic polymorphism and expression in transformed cells

The SB region of the human major histocompatibility complex (MHC) has been cloned from cosmid and lambda phage libraries made from the human B-lymphoblastoid cell line Priess (DR4/4, DC4/4, SB3/4). Two alpha genes and two beta genes are encoded in the 100 kb long SB region in the order SB alpha-SB beta-SX alpha-SX beta. The SB alpha and SB beta genes encode the alpha and beta subunits of the SB subset of class II MHC molecules. Both the SX alpha and the SX beta genes are pseudogenes in the haplotype examined. From the isolated clones, the two haplotypes of the Priess cell line, SB3 and SB4, are distinguished by nucleotide sequencing and blot hybridization analyses. Restriction site polymorphisms between the SB3 and SB4 clones were observed only in relatively small regions of the SB beta and SX beta genes. A mouse macrophage cell line was transfected with one of the cosmid clones containing both SB alpha and SB beta genes. Expression of the alpha and beta genes was detected by fluorescene-activated cell sorting (FACS) and two-dimensional gel electrophoresis using SB-specific monoclonal antibodies.     

The DNA replication origins of herpes simplex virus type 1 strain Angelotti

The nucleotide sequences of the origins of DNA replication (ori) of the S- and L-component (oriS, oriL) of the herpes simplex virus type 1 (HSV-1) standard genome were determined from HSV-1 strain Angelotti (ANG). In contrast to other HSV-1 strains, the ANG oriS sequence revealed an insertion of an TA-dinucleotide in an otherwise very conserved but imperfect palindromic sequence of 47 bp. The oriL sequence of the standard ANG genome was found to be identical to that of an ANG class II defective genome which exhibits a duplication of a 144 bp palindrome. A model is presented to explain the origination of the amplified ANG oriL sequences from the parental genome with a single copy of oriL via illegitimate recombination. Alignment of the ori sequences of HSV, adeno- and papovaviruses unveiled that the HSV ori region can be subdivided into two distinct sites of homology to the DNA initiation signals of papova- and adenoviruses, suggesting that the HSV origins of replication comprise elements for DNA replication by both, cellular and virus-encoded DNA polymerases.