bluuebunny/crossref_metadata_2025_split huggingface dataset:
POPULATION GENETICS OF DROSOPHILA AMYLASE. IV. SELECTION IN LABORATORY POPULATIONS MAINTAINED ON DIFFERENT CARBOHYDRATES
Authors: Powell Jeffrey R , Andjelković Marko 
Published: January 2021

ABSTRACT
Two polymorphic systems impinging on α-amylase in Drosophila pseudoobscura have been studied in laboratory populations maintained on medium in which the only carbohydrate source was starch (the substrate of amylase) and replicas maintained on medium in which the only carbohydrate source was maltose (the product of amylase). The two polymorphic systems were alleles at the structural gene (Amy) coding for the enzyme (allozymes) and variation in the tissue-specific expression along the adult midgut controlled by several genes. In the seven populations on maltose medium little consistent change was noted in either system. In the seven populations on starch medium, both polymorphisms exhibited selective changes. A midgut pattern of very limited expression of amylase rose in frequency in all starch populations, as did the frequency of the "fast" (1.00) Amy allele. The overall specific amylase activity did not differ between starch-adapted and maltose-adapted flies.—The results, along with previous studies, indicate that when a gene-enzyme system is specifically stressed in laboratory populations, allozymes often exhibit selective differences. Such results make the selectionist hypothesis at least tenable. Furthermore, the fact that both types of polymorphisms responded to selection indicates the role of structural gene vs. gene regulation changes in adaptive evolution is not an either/or question but one of relative roles and interactions.
GENE-CENTROMERE MAPPING IN RAINBOW TROUT: HIGH INTERFERENCE OVER LONG MAP DISTANCES
Authors: Thorgaard Gary H , Allendorf Fred W , Knudsen Kathy L 
Published: January 2021

ABSTRACT
Ten enzyme loci were mapped in relation to their centromeres in gynogenetic diploid rainbow trout. Gene-centromere map distances, calculated under the assumption of complete interference, range from 1.1 cM for Ldh4 to 50 cM for Sod1. The Idh2 and Est1 loci are linked on the same chromosome arm.—The observation of close to 100% heterozygous gynogenetic diploids for the Sod1 and Mdh3,4 loci suggests that near-complete interference occurs on the chromosome arms carrying these loci. The high interference observed in this study and in several other species of fish may be related to the small size of fish chromosome arms.—Comparisons of map locations for the Ldh3 and Ldh4 and the Mdh3 and Mdh4 loci, which were duplicated by a tetraploid event in the evolution of salmonid fish, reveal that they are located at similar distances from their centromeres. Comparative mapping of loci duplicated longer ago shows more variation in map location.—The high proportion of heterozygotes for some loci after gynogenesis involving second polar body retention demonstrates that this is not a practical method for producing homozygous inbred lines in rainbow trout; treatments suppressing the first cell division are more promising for this purpose.
ELECTROPHORETIC VARIATION FOR X CHROMOSOME-LINKED HYPOXANTHINE PHOSPHORIBOSYL TRANSFERASE (HPRT) IN WILD-DERIVED MICE
Authors: Chapman Verne M , Kratzer Paul G , Quarantillo Barbara A 
Published: January 2021

ABSTRACT
An electrophoretic variation for hypoxanthine phosphoribosyltransferase, HPRT, has been identified in samples of Mus spretus, a field mouse from southern Europe and in M. m. castaneus, a house mouse from southeast Asia. These mice will interbreed with laboratory mice to produce viable, fertile F1 progeny. The variation for HPRT segregates as an X chromosome gene in F1 and backcross progeny. Linkage analysis involving the markers Pgk-1 and Ags indicated a gene order of centromere—Hprt—Pgk-1—Ags in crosses involving both stocks of wild mice.
STRUCTURE OF GENETIC VARIATION WITHIN AND BETWEEN POPULATIONS OF MYCOPHAGOUS DROSOPHILA
Authors: Lacy Robert C 
Published: January 2021

ABSTRACT
Patterns of genetic variation within and between populations of five species of mycophagous Drosophila were examined by gel electrophoresis of several polymorphic loci. Populations of the five species could not be shown to be subdivided into sympatric host-adapted races. Statistically significant, but small, between-host differences in gene frequencies were observed at three of 15 loci. Mean gene frequencies at all loci were similar in New York and Tennessee, and, with one exception, relatively little genetic differentiation was observed among study sites within those two regions. Gene frequencies generally were stable over several years of collecting as well. The unpredictable nature of the fungal hosts may preclude the site fidelity and continuity of diversifying selection necessary for adaptive divergence of populations.
EXTRACHROMOSOMAL INHERITANCE OF CARBON DIOXIDE SENSITIVITY IN THE MOSQUITO CULEX QUINQUEFASCIATUS
Authors: Shroyer Donald A , Rosen Leon 
Published: January 2021

ABSTRACT
Mosquitoes from a laboratory colony of Culex quinquefasciatus from Matsu Island, China, develop irreversible paralytic symptoms after exposure to carbon dioxide at 1°. This CO2 sensitivity is caused by an inherited infectious agent, probably a virus. Crossing studies between CO2-sensitive and -resistant mosquitoes showed that the sensitivity trait is inherited extrachromosomally in a fashion strictly analogous to the hereditary transmission of sigma virus in Drosophila melanogaster. Sensitivity could be maintained through maternal transmission alone, despite nine generations of backcrossing of "stabilized" CO2-sensitive females to males from a resistant strain. CO2-sensitive males crossed to resistant females transmitted sensitivity to a portion of their F1 progeny, and only the female F1 sensitives were capable of further hereditary transmission.—Matsu, or a very similar hereditary infectious agent, is common in natural populations of Cx. quinquefasciatus on Oahu, Hawaii. Fifty-nine percent of the families reared from field-collected egg rafts contained CO2-sensitive mosquitoes, and some families contained only sensitive mosquitoes.
LENGTH MUTATIONS IN HUMAN MITOCHONDRIAL DNA
Authors: Cann R L , Wilson A C 
Published: January 2021

ABSTRACT
By high-resolution, restriction mapping of mitochondrial DNAs purified from 112 human individuals, we have identified 14 length variants caused by small additions and deletions (from about 6 to 14 base pairs in length). Three of the 14 length differences are due to mutations at two locations within the D loop, whereas the remaining 11 occur at seven sites that are probably within other noncoding sequences and at junctions between coding sequences. In five of the nine regions of length polymorphism, there is a sequence of five cytosines in a row, this sequence being comparatively rare in coding DNA. Phylogenetic analysis indicates that, in most of the polymorphic regions, a given length mutation has arisen several times independently in different human lineages. The average rate at which length mutations have been arising and surviving in the human species is estimated to be many times higher for noncoding mtDNA than for noncoding nuclear DNA. The mystery of why vertebrate mtDNA is more prone than nuclear DNA to evolve by point mutation is now compounded by the discovery of a similar bias toward rapid evolution by length mutation.
GENETIC METHODS FOR ANALYSIS AND MANIPULATION OF INVERSION MUTATIONS IN BACTERIA
Authors: Schmid Molly B , Roth John R 
Published: January 2021

ABSTRACT
A number of genetic methods for the isolation, characterization and manipulation of large chromosomal inversions in Salmonella typhimurium are described. One inversion-carrying mutant is characterized in detail and used to demonstrate a number of unique genetic properties of bacterial inversions.—Contrary to expectation, it was found that large inversion mutations can be repaired by generalized transduction. The repair results from the simultaneous introduction of two wild-type transduced fragments into a single recipient cell. Homologous recombination between the two transduced fragments and the two inversion breakpoints causes the inverted segment to be reinverted. This results in regeneration of the wild-type orientation of this chromosome segment. Similar recombination events allow a large inversion mutation to be introduced into a wild-type strain; two transduced fragments from an inversion strain cause recombination events resulting in inversion of a large chromosome segment.—Genetic methods for mapping the extent of a large inversion mutation by generalized transduction are described and tested. The methods are operationally simple and allow good resolution of the two inversion breakpoints.
ON THE TIME FOR GENE SILENCING AT DUPLICATE LOCI
Authors: Watterson G A 
Published: January 2021

ABSTRACT
A simple approximate formula is found for the mean time for mutant genes to first fix at one or another of two duplicate loci. The fixation is a result of one-way mutation from the wild-type to the mutant alleles, but is retarded by strong selection against the doubly homozygous mutants. The two-dimensional diffusion that models the evolution of the mutant allele frequencies at the two loci is studied by means of a transformation to two univariate diffusions having different time scales. Most of the results, but not all, agree well with the numerical studies by previous authors. Some new simulation results are presented, which agree well with the analytical results and, therefore, cast doubt on some previous simulations.
MALE-SPECIFIC LETHAL MUTATIONS OF DROSOPHILA MELANOGASTER. II. PARAMETERS OF GENE ACTION DURING MALE DEVELOPMENT
Authors: Belote John M 
Published: January 2021

ABSTRACT
The male-specific lethal mutations (msl's) identify loci whose wild-type gene products are essential for male, but not female, viability. Earlier studies in which X-linked gene activities were monitored in msl/msl male larvae demonstrated that these genes are responsible for setting and/or maintaining the level of X chromosome transcription in males (i.e., they are necessary for proper dosage compensation). The present study examines several important questions concerning their mode of action during development—The results of an examination of the effects of an msl-1 deficiency on male-lethal phase and female viability suggest that this mutation is an amorph, or a severe hypomorph. The effects of rendering a fly mutant for more than one male-lethal mutation were also examined. Multiply mutant flies were no more severely affected than singly mutant ones. A gynandromorph analysis revealed that the male-limited lethality associated with msl-2 has no single lethal focus. Somatic clones of homozygous msl-2 cells were initiated at various times during development by X-ray-induced mitotic recombination. An examination of the viability, growth patterns and morphology of marked clones demonstrated that: (1) msl-2 + acts in a cell autonomous manner, (2) msl-2 + function is required not only in larval (polytene) cells as was shown in previous work but is also needed in the diploid cells that give rise to adult structures, (3) the msl-2 + gene is needed fairly late in development and perhaps continuously, (4) the msl-2 mutation does not affect sexual differentiation.
Efficient seismic ray tracing based on the shortest path method
Authors: Sekiguchi Shoji 
Published: January 2021

SUMMARYLimiting the number of valid nodes around a reference ray can greatly reduce the calculation time of the shortest-path method (SPM). The calculation is executed by increasing the number of cells and/or nodes in the target area, step by step, until the rays converge. The ray obtained in the previous step is used as a reference ray, and the initial reference rays are given by the ordinary SPM. The Dijkstra algorithm and binary heap sorting method are used, as in the ordinary SPM. As the cell and node numbers increase, the calculation time for the modified SPM (mSPM) is reduced compared to that for the ordinary SPM. In the 3-D (100 × 100 × 100 km3) checkerboard velocity pattern model, the relative calculation time becomes two to four orders of magnitude smaller. The calculation time for the mSPM itself is approximately proportional to E log2(V), where E is the edge (ray path segment) number and V is the vertex (node) number, as seen in the heap sorting algorithm. The mean traveltime and ray path differences between the mSPM and pseudo-bending method (PBM) are small, less than 0.005 s and around 0.6 km, respectively, and slightly larger than those with respect to the ordinary SPM. The total differences from the exact solution are estimated to be less than 0.01 s and 1.0 km, which are sufficiently small for traveltime tomography. The traveltime and ray path can be improved by utilizing iterative calculations, shifting of the starting point and more neighbour nodes. The ray path obtained by the mSPM can be a local minimum, according to velocity models. The relative mean traveltime and ray path differences between adjacent cells and nodes generally show trends similar to those of the traveltime and ray path differences from the PBM. Hence, these relative differences can help reveal the behaviour of the differences from the PBM.
Is the ‘never event’ concept a useful safety management strategy in complex primary healthcare systems?
Authors: Bowie Paul , Baylis Diane , Price Julie , Bradshaw Pallavi , McNab Duncan , Ker Jean , Carson-Stevans Andrew , Ross Alastair 
Published: January 2021

Abstract

Why is the area important?
A sub-group of rare but serious patient safety incidents, known as ‘never events,’ is judged to be ‘avoidable.’ There is growing interest in this concept in international care settings, including UK primary care. However, issues have been raised regarding the well-intentioned coupling of ‘preventable harm’ with zero tolerance ‘never events,’ especially around the lack of evidence for such harm ever being totally preventable.

What is already known and gaps in knowledge?
We consider whether the ideal of reducing preventable harm to ‘never’ is better for patient safety than, for example, the goal of managing risk materializing into harm to ‘as low as reasonably practicable,’ which is well-established in other complex socio-technical systems and is demonstrably achievable.
We reflect on the ‘never event’ concept in the primary care context specifically, although the issues and the polarized opinion highlighted are widely applicable. Recent developments to validate primary care ‘never event’ lists are summarized and alternative safety management strategies considered, e.g. Safety-I and Safety-II.

Future areas for advancing research and practice
Despite their rarity, if there is to be a policy focus on ‘never events,’ then specialist training for key workforce members is necessary to enable examination of the complex system interactions and design issues, which contribute to such events. The ‘never event’ term is well intentioned but largely aspirational—however, it is important to question prevailing assumptions about how patient safety can be understood and improved by offering alternative ways of thinking about related complexities.
Dietary patterns of phyllostomid bats in interior Atlantic Forest of eastern Paraguay
Authors: Stevens Richard D , Amarilla-Stevens Heidi N 
Published: January 2021

Abstract
We examined patterns of dietary overlap of phyllostomid bats in interior Atlantic Forest of Paraguay. In addition, we examined microgeographic, seasonal, and species-specific, differences in dietary patterns. We obtained 4,519 dietary records for bats from two sites in eastern Paraguay representing 26 different kinds of resources. The three most abundant resources made up 85% of all dietary records. No significant difference in diets of phyllostomid bats existed between sites. Overlap was high and significantly greater than random. Overlap at both sites was higher in winter than in summer. Consumption of dietary items was different between seasons and reflected changes in consumption primarily of the three most consumed items. Resource breadth was narrower in winter than summer. Sites, season, and species together accounted for 71% of the variation in dietary items. Unique effects, after controlling for variation shared with other factors, of species and season were significant, whereas that of site was not. While much dietary variation in interior Atlantic Forest falls along phylogenetic lines, such patterns are weak and resource utilization appears to be substantively influenced by generalist ecology of bats and seasonal nature of the environment in this system.
Acceptability and perceived utility of different diagnostic tests and sample types for trachoma surveillance in the Bijagos Islands, Guinea Bissau
Authors: Sahota Ramandeep Singh , Sanha Salimato , Last Anna , Cassama Eunice , Goncalves Adriana , Kelly Ann H , Street Alice , Harding-Esch Emma M 
Published: January 2021

Abstract

Background
Trachoma is the leading infectious cause of blindness worldwide and is nearing elimination as a public health problem in Guinea Bissau. It is imperative that elimination is followed by a successful postvalidation surveillance programme. The aim of this study was to determine the acceptability and perceived utility of different diagnostic tests and sample types that could be used for postvalidation trachoma surveillance in the Bijagos Islands, Guinea Bissau.

Methods
Semistructured interviews with community members and stakeholders involved in trachoma elimination were followed by focus group discussions with community members, covering experiences with trachoma and views on trachoma diagnostic methods and sample types.

Results
In this setting, all diagnostic tests and sample types used for trachoma surveillance were generally considered acceptable by communities. A preference for laboratory-based testing and finger-prick blood samples was expressed as these results were considered more accurate and applicable to a range of diseases beyond trachoma.

Conclusions
Appropriate community and stakeholder engagement and communication regarding the purpose and processes around diagnostic practice prior to trachoma programme implementation are crucial for long-term successful disease-elimination efforts.
Effect of fluid resuscitation on cerebral integrity
Authors: Ziebart Alexander , Breit Christian , Ruemmler Robert , Hummel Regina , Möllmann Christian , Jungmann Florian , Kamuf Jens , Garcia-Bardon Andreas , Thal Serge C. , Kreitner Karl-Friedrich , Schäfer Michael K.E. , Hartmann Erik K. 
Published: January 2021

BACKGROUND
The treatment of haemorrhagic shock is a challenging task. Colloids have been regarded as standard treatment, but their safety and benefit have been the subject of controversial debates. Negative effects, including renal failure and increased mortality, have resulted in restrictions on their administration. The cerebral effects of different infusion regimens are largely unknown.

OBJECTIVES
The current study investigated the impact of gelatine-polysuccinate, hydroxyethyl starch (HES) and balanced electrolyte solution (BES) on cerebral integrity, focusing on cerebral inflammation, apoptosis and blood flow in pigs.

DESIGN
Randomised experimental study.

SETTING
University-affiliated large animal research unit.

ANIMALS
Twenty-four juvenile pigs aged 8 to 12 weeks.

INTERVENTION
Haemorrhagic shock was induced by controlled arterial blood withdrawal to achieve a combination of relevant blood loss (30 to 40 ml kg−1) and haemodynamic deterioration. After 30 min of shock, fluid resuscitation was started with either gelatine-polysuccinate, HES or BES. The animals were then monitored for 4 h.

MAIN OUTCOME MEASURES
Cerebral perfusion and diffusion were measured via arterial-spin-labelling MRI. Peripheral tissue perfusion was evaluated via white light spectroscopy. Cortical and hippocampal samples were collected at the end of the experiment. The numbers of cerebral cell nuclei were counted and mRNA expression of markers for cerebral apoptosis [glucose transporter protein type 1 (SLC2A), lipocalin 2 (LCN-2), aquaporin-4 (AQP4)] and inflammation [IL-6, TNF-α, glial fibrillary acidic protein (GFAP)] were determined.

RESULTS
The three fluid protocols all stabilised the macrocirculation. Fluid resuscitation significantly increased the cerebral perfusion. Gelatine-polysuccinate and HES initially led to a higher cardiac output but caused haemodilution. Cerebral cell counts (as cells μm−2) were lower after colloid administration in the cortex (gelatine-polysuccinate, 1.8 ± 0.3; HES, 1.9 ± 0.4; each P < 0.05 vs. BES, 2.3 ± 0.2) and the hippocampus (gelatine-polysuccinate, 0.8 ± 0.2; HES, 0.9 ± 0.2; each P < 0.05 vs. BES, 1.1 ± 0.1). After gelatine-polysuccinate, the hippocampal SLC2A and GFAP were lower. After gelatine-polysuccinate, the cortical LCN-2 and TNF-α expression levels were increased (each P < 0.05 vs. BES).

CONCLUSION
In a porcine model, fluid resuscitation by colloids, particularly gelatine-polysuccinate, was associated with the occurrence of cerebral injury.

ETHICAL APPROVAL NUMBER
23 177-07/G 15-1-092; 01/2016.
Assessing the antinociceptive effect of nitrous oxide to tetanic stimulation in anaesthetised patients with new intra-operative nociception monitors
Authors: Coulombe Marie-Andrée , Décary Elizabeth , Maximos Sarah , Brulotte Véronique , Drolet Pierre , Tanoubi Issam , Issa Rami , Zaphiratos Valérie , Verdonck Olivier , Fortier Louis-Philippe , Godin Nadia , Idrissi Moulay , Raft Julien , Richebé Philippe 
Published: January 2021

BACKGROUND
Nitrous oxide (N2O) has been used since the 19th century for its analgesic, antinociceptive and anxiolytic effects during surgical procedures in awake and anaesthetised patients. However, quantification of noxious stimuli that occur under general anaesthesia is a constant challenge for anaesthesiologists, and recently two new indices have been developed to assess intra-operative nociception.

OBJECTIVE
The aim of this study was to quantify with new indices as well as with more classical clinical parameters the antinociceptive effect of N2O during general anaesthesia.

DESIGN
Prospective, open label, patient-blinded, observational and descriptive trial.

SETTING
Single-centre academic hospital.

PARTICIPANTS
Forty American Society of Anesthesiologists’ physical status 1 to 3 patients undergoing general anaesthesia for elective abdominal surgery via laparotomy were recruited.

MAIN OUTCOMES MEASURES
Intra-operative pain was assessed using a standardised electrical stimulation of the forearm (tetanic stimulation at 70 mA, 100 Hz for 30 s), at 0, 25 and 50% inhaled N2O/O2. Heart rate (HR), mean arterial blood pressure, bispectral index, the analgesia nociception index and the nociception level (NOL) index were used to evaluate intra-operative nociception before and after each standardised tetanic stimulation.

RESULTS
There was a 16% reduction of the analgesia nociception index reaction, a 31% reduction of the NOL reaction and a 51% reduction of the HR reaction to a standardised electrical tetanic nociceptive stimulation during administration of 50% N2O. Administration of 50 or 25% inhaled N2O produced the same quality of antinociception based on HR and NOL index analyses. HR and the NOL index were the best parameters to identify the antinociceptive effect of intra-operatively administered N2O.

CONCLUSION
In anaesthetised patients, our study demonstrated clinically significant antinociceptive properties of N2O. Our results showed that low concentrations of N2O (25%) are as effective as higher concentrations (50%) to achieve a significant antinociceptive effect. These findings may help decrease negative effects of using higher concentrations of N2O, including its side effects and its environmental pollution.

TRIAL REGISTRATION
ClinicalTrials.gov registration identifier: NCT02701478.