First CLAS12 Measurement of Deeply Virtual Compton Scattering Beam-Spin Asymmetries in the Extended Valence Region.

Deeply virtual Compton scattering (DVCS) allows one to probe generalized parton distributions describing the 3D structure of the nucleon. We report the first measurement of the DVCS beam-spin asymmetry using the CLAS12 spectrometer with a 10.2 and 10.6 GeV electron beam scattering from unpolarized protons. The results greatly extend the Q^{2} and Bjorken-x phase space beyond the existing data in the valence region and provide 1600 new data points measured with unprecedented statistical uncertainty, setting new, tight constraints for future phenomenological studies.

First Measurement of Λ Electroproduction off Nuclei in the Current and Target Fragmentation Regions.

We report results of Λ hyperon production in semi-inclusive deep-inelastic scattering off deuterium, carbon, iron, and lead targets obtained with the CLAS detector and the Continuous Electron Beam Accelerator Facility 5.014 GeV electron beam. These results represent the first measurements of the Λ multiplicity ratio and transverse momentum broadening as a function of the energy fraction (z) in the current and target fragmentation regions. The multiplicity ratio exhibits a strong suppression at high z and an enhancement at low z. The measured transverse momentum broadening is an order of magnitude greater than that seen for light mesons. This indicates that the propagating entity interacts very strongly with the nuclear medium, which suggests that propagation of diquark configurations in the nuclear medium takes place at least part of the time, even at high z. The trends of these results are qualitatively described by the Giessen Boltzmann-Uehling-Uhlenbeck transport model, particularly for the multiplicity ratios. These observations will potentially open a new era of studies of the structure of the nucleon as well as of strange baryons.

Early evidence of establishment of the tropical bedbug (Cimex hemipterus) in Central Europe.

In recent decades, the world has witnessed a remarkable resurgence of bedbugs (Hemiptera: Cimicidae). Although populations of the common bedbug, Cimex lectularius L., expanded in temperate regions of its original distribution, the tropical bedbug, C. hemipterus (F.), increased its abundance in warmer regions, where it also had been historically distributed. However, C. hemipterus has recently been observed to be expanding to other areas, e.g. North Australia, Middle East, the United States and Russia. In other parts of Europe, few sporadic and ephemeral introductions of C. hemipterus were recorded until recently. We conducted an extensive sampling of European bedbug populations starting in 2002 and found that C. hemipterus has recently become locally established. Among 566 examined infestations, nearly all of which involved C. lectularius, C. hemipterus occurred in six infestations collected since 2019. In at least three cases, the social background of inhabitants of the infested properties indicated that tropical bedbugs likely spread within local communities. Using cytochrome oxidase subunit I, we linked five of the infestations to the most common haplotype found globally, and one to an African haplotype. In all infestations, we observed two kdr-associated mutations in the sodium channel gene, which are also commonly found across the world.

Venom Complexity in a Pitviper Produced by Facultative Parthenogenesis.

Facultative parthenogenesis (FP) is asexual reproduction in plant and animal species that would otherwise reproduce sexually. This process in vertebrates typically results from automictic development (likely terminal fusion) and is phylogenetically widespread. In squamate reptiles and chondrichthyan fishes, FP has been reported to occur in nature and can result in the production of reproductively viable offspring; suggesting that it is of ecological and evolutionary significance. However, terminal fusion automixis is believed to result in near genome-wide reductions in heterozygosity; thus, FP seems likely to affect key phenotypic characters, yet this remains almost completely unstudied. Snake venom is a complex phenotypic character primarily used to subjugate prey and is thus tightly linked to individual fitness. Surprisingly, the composition and function of venom produced by a parthenogenetic pitviper exhibits a high degree of similarity to that of its mother and conspecifics from the same population. Therefore, the apparent loss of allelic diversity caused by FP appears unlikely to have a significant impact on the prey-capturing ability of this snake. Accordingly, the pitviper offspring produced by FP retained complex phenotypic characteristics associated with fitness. This result reinforces the potential ecological and evolutionary importance of FP and questions our understanding of the inheritance of venom-associated genes.

Motion-insensitive carotid intraplaque hemorrhage imaging using 3D inversion recovery preparation stack of stars (IR-prep SOS) technique.

PURPOSE: Carotid artery imaging is important in the clinical management of patients at risk for stroke. Carotid intraplaque hemorrhage (IPH) presents an important diagnostic challenge. 3D magnetization prepared rapid acquisition gradient echo (MPRAGE) has been shown to accurately image carotid IPH; however, this sequence can be limited due to motion- and flow-related artifact. The purpose of this work was to develop and evaluate an improved 3D carotid MPRAGE sequence for IPH detection. We hypothesized that a radial-based k-space trajectory sequence such as "Stack of Stars" (SOS) incorporated with inversion recovery preparation would offer reduced motion sensitivity and more robust flow suppression by oversampling of central k-space. MATERIALS AND METHODS: A total of 31 patients with carotid disease (62 carotid arteries) were imaged at 3T magnetic resonance imaging (MRI) with 3D IR-prep Cartesian and SOS sequences. Image quality was determined between SOS and Cartesian MPRAGE in 62 carotid arteries using t-tests and multivariable linear regression. Kappa analysis was used to determine interrater reliability. RESULTS: In all, 25 among 62 carotid plaques had carotid IPH by consensus from the reviewers on SOS compared to 24 on Cartesian sequence. Image quality was significantly higher with SOS compared to Cartesian (mean 3.74 vs. 3.11, P < 0.001). SOS acquisition yielded sharper image features with less motion (19.4% vs. 45.2%, P < 0.002) and flow artifact (27.4% vs. 41.9%, P < 0.089). There was also excellent interrater reliability with SOS (kappa = 0.89), higher than that of Cartesian (kappa = 0.84). CONCLUSION: By minimizing flow and motion artifacts and retaining high interrater reliability, the SOS MPRAGE has important advantages over Cartesian MPRAGE in carotid IPH detection. LEVEL OF EVIDENCE: 1 J. Magn. Reson. Imaging 2017;45:410-417.

Extensive Mitochondrial Heteroplasmy in Natural Populations of a Resurging Human Pest, the Bed Bug (Hemiptera: Cimicidae).

Homoplasmy, the occurrence of a single mitochondrial DNA haplotype within an individual, has been the accepted condition across most organisms in the animal kingdom. In recent years, a number of exceptions to this rule have been reported, largely due to the ease with which single nucleotide polymorphisms can be detected. Evidence of heteroplasmy-two or more mitochondrial variants within a single individual-has now been documented in a number of invertebrates; however, when present, heteroplasmy usually occurs at low frequencies both within individuals and within populations. The implications of heteroplasmy may be far reaching, both to the individual in relation to its health and fitness, and when considering the evolutionary dynamics of populations. We present novel evidence for frequent mtDNA heteroplasmy in the bed bug, Cimex lectularius L. (Hemiptera: Cimicidae). Our findings show that heteroplasmy is common, with 5 of 29 (17%) populations screened exhibiting two mitochondrial variants in a ∼1:2 ratio within each individual. We hypothesize that the mechanism underlying heteroplasmy in bed bugs is paternal leakage because some haplotypes were shared among unrelated populations and no evidence for nuclear mitochondrial DNA sequences was detected.

Genome size and ploidy of Thysanoptera.

Flow cytometry was used to study the genome sizes and ploidy levels for four thrips species: Franklinothrips orizabensis Johansen (Thysanoptera: Aeolothripidae), Frankliniella occidentalis Pergande, Frankliniella fusca Hinds, and Thrips tabaci Lindeman (Thysanoptera: Thripidae). F. orizabensis males and females had 1C genome sizes of 426 Mb and 422 Mb, respectively. Male and female F. fusca had 1C genome sizes of 392 Mb and 409 Mb, whereas F. occidentalis males and females had smaller 1C genomes that were 345 Mb and 337 Mb, respectively. Male F. orizabensis, F. occidentalis and F. fusca were haploid and females diploid. Five isofemale lines of T. tabaci, initiated from parthenogenetic, thelytokous females and collected from different locations in North Carolina, were included in this study; no males were available. One isofemale line was diploid with a genome size of 1C = 310 Mb, and the other four had a mean genome size of 1C = 482 Mb, which is consistent with evidence from microsatellite data of diploidy and polyploidy, respectively, in these same five thelytokous lines. This is the first study to produce genome size estimates for thysanopteran species, and report polyploidy in T. tabaci populations.

Identification and characterization of 15 polymorphic microsatellite loci in the western drywood termite, Incisitermes minor (Hagen).

Despite recognition of the western drywood termite, Incisitermes minor (Hagen), as one of the most economically important and destructive termite species in the USA, both its population and colony breeding structure genetically remain unclear. Here, we present primer sequences and initial characterization for 15 polymorphic microsatellite loci. In a sample of 30 individuals, representing six geographically distinct locations collected in California, USA, three to 15 alleles were detected segregating per locus. Within a single population observed heterozygosity ranged from 0.050 to 0.866.

Succession of fungi on dead and live wood in brackish water in Brunei.

We observed the sequence of fungi appearing on submerged wood of Hibiscus tiliaceus that initially was either dead or alive. Branches that were dead, but still attached to the tree, and live branches were cut from H. tiliaceus in the riparian vegetation in a brackish habitat on the Tutong River, Brunei. Branch segments were connected to the riverbank using monofilament line. Samples were examined for fungi before the branches were placed in the river and after the branches had been submerged 3 or 6 mo. Fifty taxa were found on the samples. Before being placed in the water different fungal assemblages were found on live as compared to deadwood. Branches that were alive when cut supported a distinctly different fungal assemblage after 3 mo in the water. Dead branches after 3 mo and both dead and initially live samples after 6 mo had been colonized by a fungal assemblage that is typical at this site. It is unknown whether the differences in colonization of dead and initially live wood can be attributed to differences in the substratum (i.e., the presence or absence of bark), inhibitory substances in more recently live wood or to assembly rules resulting from the different fungi that already were present in dead and live branches.

Laparoscopic incisional and ventral herniorraphy: our initial 100 patients.

A review of our initial 100 patients upon whom we attempted a laparoscopic repair of either a ventral and incisional hernia is presented. The average follow-up period of these individuals was 51 months. The operation was completed with the laparoscopic technique in 96 cases. The average defect size was 155 cm2 and the average prosthetic biomaterial size to repair these defects was 214.8 cm2. The major complication rate was 4.1%. The incidence of recurrence in these patients was 9.3%. In all of these cases of recurrence, the method of attachment was that of staples or spiral tacks alone. In 5 patients, it appeared that the prosthesis was too small to cover the defect adequately. We believe that this is an effective operation but one that has two technical mandates. The prosthetic biomaterial (DualMesh) must cover the fascial edges by a minimum of a three-centimeter overlap. Additionally, the attachment of the patch by staples or tacks alone is inadequate; consequently, the herniorraphy must include the use of through and through sutures to assure adequate fixation of the prosthesis.

Laparoscopic incisional and ventral herniorrhaphy in 100 patients.

BACKGROUND: Laparoscopic incisional and ventral herniorrhaphy, a procedure first described 7 years ago, continues to gain acceptance. A series of about 100 patients who underwent the operation is described. Follow-up in this series was longer (mean 51 months) than that in previously reported series. METHODS: A retrospective review was conducted of operative and follow-up records of a series of patients scheduled to undergo laparoscopic incisional or ventral herniorrhaphy between 1992 and 1997. RESULTS: Laparoscopic repair was completed in 96 of 100 patients. The complication rate was 14%, with seromas accounting for half of the postoperative problems. Mean hospital stay was 1 day. The late recurrence rate was 9%, with 4 of the 9 recurrences developing >2 years postoperatively. CONCLUSIONS: Laparoscopic incisional and ventral herniorrhaphy is safe and effective. Most patients require hospitalization for /=3 years.

Building sickness syndrome in healthy and unhealthy buildings: an epidemiological and environmental assessment with cluster analysis.

OBJECTIVES: Building sickness syndrome remains poorly understood. Aetiological factors range from temperature, humidity, and air movement to internal pollutants, dust, lighting, and noise factors. The reported study was designed to investigate whether relations between symptoms of sick building syndrome and measured environmental factors existed within state of the art air conditioned buildings with satisfactory maintenance programmes expected to provide a healthy indoor environment. METHODS: Five buildings were studied, three of which were state of the art air conditioned buildings. One was a naturally ventilated control building and one a previously studied and known sick building. A questionnaire was administered to the study population to measure the presence of building related symptoms. This was followed by a detailed environmental survey in identified high and low symptom areas within each building. These areas were compared for their environmental performance. RESULTS: Two of the air conditioned buildings performed well with a low prevalence of building related symptoms. Both of these buildings out performed the naturally ventilated building for the low number of symptoms and in many of the environmental measures. One building (C), expected to perform well from a design viewpoint had a high prevalence of symptoms and behaved in a similar manner to the known sick building. Environmental indices associated with symptoms varied from building to building. Consistent associations between environmental variables were found for particulates (itchy eyes, dry throat, headache, and lethargy) across all buildings. There were persisting relations between particulates and symptoms (headache, lethargy, and dry skin) even in the building with the lowest level of symptoms and of measured airborne particulates (building B). There were also consistent findings for noise variables with low frequency noise being directly associated with symptoms (stuffy nose, itchy eyes, and dry skin) and higher frequency noise being relatively protective across all buildings. CONCLUSIONS: This is the first epidemiological study of expected state of the art, air conditioned buildings. These buildings can produce an internal environment better than that of naturally ventilated buildings for both reported symptoms and environmental variables. The factors associated with symptoms varied widely across the different buildings studied although consistent associations for symptoms were found with increased exposure to particulates and low frequency noise.

Against the odds: growing up with parents who have learning difficulties.

For this article we drew on material from a study in which we explored how people who were brought up in a family headed by a parent or parents with learning difficulties managed the transition to adulthood. Using evidence from in-depth interviews, we provided an assessment of how the now-adult children came through what would generally be seen as a risk-filled upbringing. Despite the problems they encountered in their childhood, many of which originated outside the home, most of the informants had maintained a valued relationship with their family and remained close to their mother.

In vivo study of meshes implanted over the inguinal ring and external iliac vessels in uncastrated pigs.

BACKGROUND: The effects of placing a prosthesis directly on the internal inguinal ring and external iliac vessels in inguinal hernia repair are unknown. We compared tissue responses to five prostheses implanted in this position in uncastrated male pigs. METHODS: Three types of polypropylene and two types of expanded polytetrafluoroethylene (ePTFE) mesh were implanted in 20 pigs (n = 8 for each prosthesis type). Specimens of the implants and surrounding tissue were obtained 30 and 90 days after implantation and assessed histologically. RESULTS: The polypropylene implants had more adhesions, more surface area covered by adhesions, and more tenacious adhesions than did the ePTFE implants. Perivascular cuffing was observed in eight polypropylene and one ePTFE specimen; ossification, necrosis, and testicular venous congestion were seen in polypropylene specimens. CONCLUSIONS: Abnormal healing processes after implantation of polypropylene mesh may increase complications of the transabdominal preperitoneal and total extraperitoneal approaches in laparoscopic inguinal hernia repair, whereas the minimal response to ePTFE meshes may make them safer for use in the preperitoneal space.

The amino Acid sequence glutamine-628 to valine-646 within the A1 repeat domain mediates binding of von Willebrand factor to bovine brain sulfatides and equine tendon collagen.

von Willebrand Factor (vWF) is a multifunctional glycoprotein in plasma and vascular subendothelial matrix which plays a major role in cellular adhesion. vWFdependent adhesion of platelets to the subendothelium at high shear rates involves a specific platelet membrane receptor, the glycoprotein (GP) Ib-IX complex. We have previously purified a 39/34-kiloDalton (kDa) dispase fragment of vWF (Leu-480/Val-481 to Gly-718) and demonstrated that this fragment contains the binding site for the GP Ib-IX complex [Andrews R K, et al. Biochemistry 1989; 28: 8326-83361. vWF also mediates agglutination of erythrocytes by a mechanism that appears to involve binding to membrane sulfatides. In this study, we demonstrate that the 39/34-kDa vWF fragment also contains an exclusive discrete binding domain for membrane sulfatides and that the sulfatide-binding sequence also mediates binding of vWF to equine tendon collagen. Specific binding of (125)I-vWF to sulfatides immobilized on microtiter wells was completely inhibited by unlabeled vWF (IC(50)∼0.02 µ;M) and by the isolated 39/34-kDa vWF fragment (IC(50)∼0.8 µ;M). A specific anti-39/34-kDa fragment rabbit polyclonal antibody, but not nonimmune immunoglobulin, also strongly inhibited the vWF-sulfatide interaction in this assay. Using synthetic peptides corresponding to hydrophilic sequences from within the 39/34-kDa vWF fragment, a positively-charged sequence, Gln-628 to Val-646, was identified as mediating specific binding of vWF to sulfatides, since it competitively inhibited this interaction (IC(50)∼0.6 µ;M) comparable on a molar basis to the 39/34-kDa vWF fragment (IC, -0.8 µ;M). The inhibition by the Gln-626 to Val-646 peptide was specific since neither other peptides from the 39/34-kDa domain of vWF nor another highly basic peptide, polylysine, at comparable concentrations to the Gln-628 to Val-646 peptide blocked vWF binding to sulfatides. Similarly, the Gln-628 to Val-646 peptide blocked binding of vWF to equine tendon type I collagen (IC(50) of 0.6 µ;M) suggesting that this interaction probably involves recognition of a sulfatide-like impurity in the collagen preparation. The specific binding of vWF to sulfatides via a discrete peptide sequence, Gln-628 to Val-646, within the A1 repeat domain suggests the potential for involvement of sulfatides as a class of receptors for vWF in cellular adhesion.

Inhibition of Binding of von Willebrand Factor to the Platelet Glycoprotein Ib-IX Complex, Heparin and Sulfatides by Polyanionic Compounds. The Mechanism of Modulation of the Adhesive Function of von Willebrand Factor.

The interaction of the multimeric glycoprotein von Willebrand Factor (vWF) with its platelet membrane receptor, the glycoprotein (GP) Ib-IX complex plays a key role in the initial adhesion of platelets to the vascular subendothelium at high shear blood flow. The GP Ib-IX-binding site is only expressed following activation of vWF, a process that regulates vWF-mediated platelet adhesion. Binding of vWF to the GP Ib-IX complex involves the vWF A1 internal repeat domain, which also contains distinct binding sites for sulfatides, heparin, and the non-physiological modulators of the vWF-GP Ib-IX interaction, ristocetin and botrocetin. With the ultimate aim of further defining the mechanism of vWF modulation, we have analyzed the ability of various polyanionic compounds, including aurintricarboxylic acid, Evans blue, fucoidan, and a range of sulfated and phosphorylated sugars, to inhibit specific binding of purified vWF to immobilized sulfatides and heparin, and the ristocetin- and botrocetindependent binding of vWF to the platelet GP Ib-IX complex. Firstly, it was confirmed using a solid-phase binding assay that, like sulfatides, heparin specifically bound to a purified 39/WkiloDalton fragment of vWF (Leu-480 to Gly-718) that encompasses the A1 domain. Secondly, the ability of a number of polyanionic compounds to inhibit binding of vWF to heparin, but not to immobilized sulfatides, supported previous data suggesting that heparin and sulfatides bind to distinct sites on vWF. In addition, aurintricarboxylic acid, Evans blue and fucoidan all inhibited binding of vWF to both heparin and sulfatides with similar ICso values. Thirdly, many of the compounds tested that inhibited binding of vWF to heparin also effectively inhibited both ristocetin- and botrocetin-dependent binding of vWF to the GP Ib-IX complex on platelets, whereas none of the compounds tested blocked vWF binding to sulfatides and GP Ib-IX but not heparin. The majority of compounds tested inhibited the vWF-platelet interaction to a comparable degree in the presence of ristocetin or botrocetin, suggesting a similar mechanism for inhibition irrespective of the modulator used. These combined experiments provide evidence for an electrostatic model of vWF modulation, and suggest that the heparin-binding domain of vWF may be an important regulatory site involved in the adhesion of vWF to the platelet GP Ib-IX complex.

The use of depth interviewing with vulnerable subjects: lessons from a research study of parents with learning difficulties.

This paper explores the practicalities of using the technique of depth interviewing with people who have learning difficulties. The authors set out to provide other researchers with guidance in the use of the life story approach and to demonstrate its utility with this vulnerable and devalued group of informants. They conclude that depth interviewing can provide new knowledge not accessible through other methods of data collection, and offers a way of giving people with learning difficulties a voice in the making of their own history.