bluuebunny/crossref_metadata_2025 huggingface dataset:
Urban regeneration of ghost cities
Authors: Devan Keerthana S , Bindu CA
Published: April 2021

Ghost cities are abandoned urban area, town, or city, usually one that contains substantial visible remains. Cities are socio-technical systems, precariously integral, capable of growing as well as becoming smaller and fragmented but still functioning. Even though they have a resilient inherent quality, many cities around the world are witnessing slow death. The reasons could be ecological and social debasement, diminishing opportunities for the young population, moving of financial focuses, poor administration, loss of character and so. Thus, a ghost city is reflected in everything from that point, in its type of capacity and in particular the functionaries – the city dwellers. Ghost cities are relinquished urban zone, town, or city, normally one that contains as yet existing noticeable remains. The greater part of the cities is confronting decline of social, economic, physical and environmental issues. Urban regeneration the practice to overcome the decline of the vitality and viability of town centres across several cities world over. Project handles the issues of decline and urban decay, have structured complex processes of urban regeneration. The regeneration strategies are mainly based on Enhancing & Protecting Social values, Development of Economic values, Improvement of Physical & environmental values. Urban regeneration is interlinked missions creating clean, sanitized, healthy, liveable, economically vibrant and responsive cities propagate ‘Planning’ as a fundamental tool for sustainable development. Urban regeneration processes focusing on all elements of an area that help contribute to the creation of a more sustainable city and environment.
Understanding the need of satellite towns in India
Authors: Ananda Krishnan S , Sujith K M
Published: April 2021

Satellite cities are planned cities, adjacent to a prime city. Such cities manage and contain the increasing urban sprawl. They are designed for a major city to extend in all possible ways. They are to house and utilize a mushrooming population; the individuals might fabricate an interest for development of the current settlement in a metropolitan city. Satellite cities are entirely standalone cities, planned, and developed outside metros. They are self-containing, independent cities. Here this paper aims to study the importance of satellite cities, its connection with parent city and how it is perceived in city planning. The paper also try to evolve a set of strategies that to be incorporated while planning so that a satellite town will become a feasible option for solving the issues of metropolitan cities. Satellite town is one of the main options that can be adopted in our current scenario. The government of India also encourages the development of satellite towns as one of the solutions to solve the issues of congested cities.
Urban liquid waste management: bane to boon-a study of Palakkad town in Kerala
Authors: Aneesa S , Arathi N , Geetha A
Published: April 2021

A clean and healthy environment is part and parcel of the wealth and the quality of life that desire for ourselves now and for children in the future. The mismanagement of wastewater in urban areas possesses a major challenge. Together, the waste water discharge and waste disposal had brought about degenerative effects on human well-being and environment which made uneasiness on urban day to day life. Thus, there is an immense need of an effective liquid waste management for a sustainable healthy environment. Since Palakkad municipal area which is chosen for the study lacks a well-defined sewerage network within the city which possesses immense health and environmental risks owing to chaotic urban life. Thus, there is a need for an integrated liquid waste management plan for the region for a booming and healthy urban life. This research explores the effective management of liquid wastes generated within the study domain as part of urban life and how it could be carried out in an effective manner minimizing environmental and health risks. Also, suggesting reuse alternatives from the processed wastes to restore the 3Rs to bring back sustainability. An effective liquid waste management is an essential service core of an urban area and a most important sector for a planned development which cannot be secluded and have to be given equal priority as that of other sectors. Thus, adopting some effective practices would minimize the issues spawned due to the haphazard management of liquid wastes, enabling a clean and healthy city.
Power spectral estimation of engine block vibrations to classify and predict the occurrence of knock
Authors: Antonio Joseph V K , Kumaran Thampi Gireesh
Published: April 2021

The study focuses on developing a sophisticated technology for determining the occurrence of knocking in SI engines. Fast Fourier Transform is performed on the engine block vibration signal to obtain the power spectral estimation. Window size of the signal is varied to extract the signals produced during the combustion inside each cylinder alone. The results obtained show that there is a clear demarcation between the power spectrum obtained during the occurrence of knock and normal combustion. Also, knock can be classified based on the intensity as strong, moderate or weak by analysing the vibration signals alone. This technique makes it suitable to be used in SI engine to investigate the combustion process in all the cylinders individually using an accelerometer mounted on the engine block.
Modelling and simulation of semi-automatic glass window cleaning machine
Authors: Abhijith Kumar A , Akhil R K , Ajnas A A , Abdul Vasih E V , Jithu J
Published: April 2021

The proposed design of the glass cleaning robot has two columns, each of whose ends are connected to four vacuum suction cups. Vacuum ducts connect the suction cups to the vacuum pump. Solenoid valves are used for controlling the suction in the suction cups so that the effective movement of the legs can be achieved. The vacuum supply to the two suction cups at the end of one column is cut off for moving the robot. Now, the pneumatic piston is used to move that column while keeping the other column fixed. This helps in the vertical motion of the robot. Similarly, another set of columns connected to a pneumatic piston is fixed perpendicular to the vertical column, which enables the robot to move in a horizontal direction. A cleaning unit is attached to the robot for the desired cleaning purpose. It consists of a microfiber brush, which continually cleans the surface as the robot moves with the help of a DC motor. A CAD model was designed and a static stress analysis while the robot is fixed on the surface was done using Autodesk® Fusion™ 360. The movement of the robot on vertical as well as on inclined surface is simulated. The results of the analysis show that the robot can successfully hold on to the wall with four suction cups and is able to climb vertical surfaces with more ease than inclined surfaces.
High specific strength steel as an alternative material for heavy vehicle chassis – an explicit analysis
Authors: Aathira K U , Keerthi V C , Arjun S , Kiran S J , Ramesh S
Published: April 2021

The chassis frame forms the backbone of a heavy vehicle which carries the load for all designed operating conditions. An important consideration in chassis design is adequate bending stiffness along with strength for better handling characteristics. Maximum shear stress and deflection are the important criteria in chassis design. The present paper is on the design of heavy vehicle chassis and its strength and rigidity analysis. In the analysis under identical load conditions, currently used chassis materials like low and medium carbon steels and cast iron are compared with high specific strength steel which can be an effective substitute material for the chassis. High specific strength steel has low density and possesses high strength properties. The dimensions of an existing vehicle chassis of AMW 2523 TP truck is taken for analysis. Rectangular Box type cross section is considered as it is observed to undergo least deflection. For validation the design is done by applying the vertical loads acting on different horizontal cross sections. The modelling and analysis are performed using SOLIDWORKS 2016 and ANSYS16.0. The results show that HSSS has the least deformation and stress induced and the proposed material provides enough strength and rigidity to the chassis.
Mechanical, thermal and morphological characterization of PP/PS/HDPE ternary immiscible polymer blend for light weight automotive applications
Authors: Surej Rajan C , Alen Varghese Lity , Joseph Shiny , George Soney C
Published: April 2021

Thermoplastic polymer blends investigation is significant because of the broad applications in automotive, aerospace, electrical appliances, etc. In this study ternary polymer blends of polypropylene (PP)/polystyrene (PS)/high-density polyethylene (HDPE) were prepared which bear superior properties appropriate for light weight automobile applications. The mechanical, thermal and morphological properties of these mixes were analyzed which promotes the application areas to which it is suitable for. PP can enhance the properties when used as a blend with other thermoplastics namely polystyrene and high-density polyethylene. The dispersed phase of minor components strengthens continuous phase by energy barring properties within the limitations. The mechanical and thermal properties of ternary blend is found to be higher than that of binary blends. The maximum value obtained for tensile strength, flexural strength and impact strength are 39.72 MPa, 49.47 MPa, 28.80 kJ/m2 which are higher than binary blend and raw polymer. The results exhibit a stronger prospect for these blends even without the addition of compatibilizer.
Bioengineered in vitro 3D model of myotonic dystrophy type 1 human skeletal muscle
Authors: Fernández-Garibay Xiomara , Ortega María A , Cerro-Herreros Estefanía , Comelles Jordi , Martínez Elena , Artero Rubén , Fernández-Costa Juan M , Ramón-Azcón Javier
Published: April 2021

Myotonic dystrophy type 1 (DM1) is the most common hereditary myopathy in the adult population. The disease is characterized by progressive skeletal muscle degeneration that produces severe disability. At present, there is still no effective treatment for DM1 patients, but the breakthroughs in understanding the molecular pathogenic mechanisms in DM1 have allowed the testing of new therapeutic strategies. Animal models and in vitro two-dimensional cell cultures have been essential for these advances. However, serious concerns exist regarding how faithfully these models reproduce the biological complexity of the disease. Biofabrication tools can be applied to engineer human three-dimensional (3D) culture systems that complement current preclinical research models. Here, we describe the development of the first in vitro 3D model of DM1 human skeletal muscle. Transdifferentiated myoblasts from patient-derived fibroblasts were encapsulated in micromolded gelatin methacryloyl-carboxymethyl cellulose methacrylate hydrogels through photomold patterning on functionalized glass coverslips. These hydrogels present a microstructured topography that promotes myoblasts alignment and differentiation resulting in highly aligned myotubes from both healthy and DM1 cells in a long-lasting cell culture. The DM1 3D microtissues recapitulate the molecular alterations detected in patient biopsies. Importantly, fusion index analyses demonstrate that 3D micropatterning significantly improved DM1 cell differentiation into multinucleated myotubes compared to standard cell cultures. Moreover, the characterization of the 3D cultures of DM1 myotubes detects phenotypes as the reduced thickness of myotubes that can be used for drug testing. Finally, we evaluated the therapeutic effect of antagomiR-23b administration on bioengineered DM1 skeletal muscle microtissues. AntagomiR-23b treatment rescues both molecular DM1 hallmarks and structural phenotype, restoring myotube diameter to healthy control sizes. Overall, these new microtissues represent an improvement over conventional cell culture models and can be used as biomimetic platforms to establish preclinical studies for myotonic dystrophy.
Consider This Before Using the Severe Acute Respiratory Syndrome Coronavirus 2 Pandemic as an Instrumental Variable in an Epidemiologic Study
Authors: Dimitris Michelle C , Platt Robert W
Published: April 2021

Epidemiologists sometimes use external sources of variation to explore highly confounded exposure-outcome relationships or exposures that cannot be randomized. These exogenous sources of variation, or natural experiments, are sometimes proposed as instrumental variables to examine the effects of given exposures on given outcomes. Previous epidemiologic studies have applied this technique using famines, earthquakes, weather events, and previous pandemics as exogenous sources of variation for other exposures; interest in applying this technique using the current severe acute respiratory system coronavirus 2 (SARS-CoV-2) pandemic is already documented. Yet large-scale events like these likely have broad and complicated impacts on human health, which almost certainly violates the exclusion restriction assumption of instrumental variable analyses. We review the assumptions of instrumental variable analyses, highlight previous applications of this method with respect to natural experiments with broad impacts or “shocks,” and discuss how these relate to our current observations of the SARS-CoV-2 pandemic. While we encourage thorough investigation of the broad impacts of the SARS-CoV-2 pandemic on human health, we caution against its widespread use as an instrumental variable to study other exposures of interest.
Knightian uncertainty: through a Jamesian window
Authors: Rizzo Mario J , Dold Malte
Published: April 2021

Frank Knight is famous for the distinction between risk and uncertainty. In this paper, we argue that Knight’s distinction is different from the one made by those who seek to interpret it within a neoclassical framework. Knight does not reduce ‘true uncertainty’ to the application of (axiomatic) subjective probability. Instead, Knight highlights the power of intuitive judgement in situations of uncertainty. Moreover, Knight conceptualises uncertainty along a continuum which means that many of our real-world problems must be seen as mixed cases of risk and uncertainty. This paper illustrates that Knight’s arguments can be more fully understood through the lens of William James’s psychology, which deeply influenced Knight’s way of thinking. Finally, this paper links Knight’s argument to a growing body of recent empirical literature that shows how effective judgemental–intuitive modes of reasoning are in cases of environmental instability. In doing so, this paper begins to fill out the uncertainty framework, which Knight has sketched in Risk, Uncertainty and Profit (1921).
A Survey on Recommender Systems for Internet of Things: Techniques, Applications and Future Directions
Authors: Altulyan May , Yao Lina , Wang Xianzhi , Huang Chaoran , Kanhere Salil S , Sheng Quan Z
Published: April 2021

Recommendation is a critical tool for developing and promoting the benefits of the Internet of Things (IoT). In recent years, recommender systems have attracted considerable attention in many IoT-related fields such as smart health, smart home, smart tourism and smart marketing. However, traditional recommender system approaches fail to exploit ever-growing, dynamic and heterogeneous IoT data in building recommender systems for the IoT (RSIoT). This article aims to provide a comprehensive review of state-of-the-art RSIoT, including the related techniques, applications and a discussion on the limitations of applying recommendation systems to IoT. Finally, we propose a reference framework for comparing existing studies to guide future research and practices.
Culture and Contracts: The Historical Legacy of Forced Labour
Authors: Blouin Arthur
Published: April 2021

Can divide-and-rule colonial policy be responsible for contemporary ethnic tension? This paper empirically investigates the role of a divisive and extractive colonial policy on Hutu–Tutsi discord in Rwanda and Burundi. It shows that Hutu with a family history of subjugation to forced labour by Tutsi chiefs are less trusting of Tutsi today and less willing to partner with Tutsi for a cooperative task. This may have implications for agriculture insurance agreements because Hutu are more agrarian and Tutsi are more pastoral. Indeed, Hutu with a forced labour family history make fewer inter-household insurance agreements and are more likely to experience default.
In-house 3D-printed aligners: effect ofin vivoageing on mechanical properties
Authors: Can Esad , Panayi Nearchos , Polychronis Georgios , Papageorgiou Spyridon N , Zinelis Spiros , Eliades George , Eliades Theodore
Published: April 2021

Objective

To investigate alterations in the mechanical properties of in-house three-dimensional (3D) printed orthodontic aligners after intraoral ageing.

Materials and methods

Sixteen 3D-printed aligners (TC-85DAC resin, Graphy, Seoul, Korea) were used for the purpose of the study, which were divided into 10 control (not used) aligners and 6 materials retrieved from 4 patients after 1-week service (retrieved group). Samples from the control group were analysed by attenuated total reflectance-Fourier-transform infrared (ATR-FTIR) spectroscopy. Samples from control/retrieved groups were embedded resin and subjected to instrumented indentation testing (IIT) to record force–indentation depth curves, calculating the following (as per ISO 14577-1, 2002 standard): Martens hardness (HM), indentation modulus (EIT), and elastic index (ηIT), and the indentation relaxation index (RIT). Differences between control and retrieved 3D-printed aligners were checked with Mann–Whitney/t-tests at an alpha = 5%.

Results

ATR-FTIR analysis showed that aligners were made of a vinyl ester–urethane material. The results of the IIT testing were: HM (control: median 91.5 N/mm2, interquartile range [IQR] 88.0–93.0/as-retrieved: median 90.5 N/mm2, IQR 89.0–93.0); EIT (control, mean 2616.3 MPa, standard deviation [SD] 107.0 MPa/retrieved, mean 2673.2 MPa, SD 149.4 MPa); ηIT (control: median 28.6%, IQR 28.2–30.9%/as-retrieved: median 29.0%, IQR 28.7–29.2%); and RIT (control: median 45.5%, IQR 43.0–47.0%/as-retrieved: median 45.1%, IQR 45.0–45.3%). No differences between as-retrieved and control aligners were found for any of the mechanical properties tested (P > 0.05 in all instances).

Conclusion

The mechanical properties of the in-house 3D-printed aligners tested were not affected after 1 week in service period.
Complications of implantable cardioverter-defibrillator treatment in arrhythmogenic right ventricular cardiomyopathy
Authors: Christensen Alex Hørby , Platonov Pyotr G , Svensson Anneli , Jensen Henrik K , Rootwelt-Norberg Christine , Dahlberg Pia , Madsen Trine , Frederiksen Tanja Charlotte , Heliö Tiina , Haugaa Kristina H , Bundgaard Henning , Svendsen Jesper H
Published: April 2021

Aims

Treatment with implantable cardioverter-defibrillators (ICD) is a cornerstone for prevention of sudden cardiac death in arrhythmogenic right ventricular cardiomyopathy (ARVC). We aimed at describing the complications associated with ICD treatment in a multinational cohort with long-term follow-up.

Methods and results

The Nordic ARVC registry was established in 2010 and encompasses a large multinational cohort of ARVC patients, including their clinical characteristics, treatment, and events during follow-up. We included 299 patients (66% males, median age 41 years). During a median follow-up of 10.6 years, 124 (41%) patients experienced appropriate ICD shock therapy, 28 (9%) experienced inappropriate shocks, 82 (27%) had a complication requiring surgery (mainly lead-related, n = 75), and 99 (33%) patients experienced the combined endpoint of either an inappropriate shock or a surgical complication. The crude rate of first inappropriate shock was 3.4% during the first year after implantation but decreased after the first year and plateaued over time. Contrary, the risk of a complication requiring surgery was 5.5% the first year and remained high throughout the study period. The combined risk of any complication was 7.9% the first year. In multivariate cox regression, presence of atrial fibrillation/flutter was a risk factor for inappropriate shock (P < 0.05), whereas sex, age at implant, and device type were not (all P > 0.05).

Conclusion

Forty-one percent of ARVC patients treated with ICD experienced potentially life-saving ICD therapy during long-term follow-up. A third of the patients experienced a complication during follow-up with lead-related complications constituting the vast majority.
Factors associated with changes in consumption among smokers and alcohol drinkers during the COVID-19 ‘lockdown’ period
Authors: Reynolds Ciara M E , Purdy Joanna , Rodriguez Lauren , McAvoy Helen
Published: April 2021

Background

The impact of the COVID-19 public health social measures (PHSM) on health behaviours is poorly understood. We aimed to identify factors associated with changes in alcohol and tobacco consumption during the strictest period of PHSM ‘lockdown’.

Methods

Logistic regression analysis was conducted using secondary data from the Central Statistics Office Social Impact Survey collected during the first lockdown in Ireland (23 April– 1 May 2020).

Results

Of the 1362 (33.8%) individuals that responded to the survey, 80.6% were current drinkers and 26.0% were smokers. The majority of smokers (60.9%) and drinkers (60.6%) reported no change in consumption. However, 30.5% of smokers and 22.2% of drinkers reported increased consumption. Being concerned about household stress from confinement [adjusted odds ratio (aOR) 1.9, 95% confidence interval (CI) 1.3–2.9, P = 0.002], working from home (aOR 2.1, 95 CI 1.4–3.3, P < 0.001) and urban living (aOR 2.0, 95 CI 1.5–2.9, P < 0.001) were associated with increases in alcohol consumption. Feeling very nervous (aOR 2.2, 95% CI 1.2–4.0, P = 0.009), feeling downhearted/depressed (aOR 2.4, 95% CI 1.3–4.4, P = 0.004), being concerned about someone else’s health (aOR 2.0, 95% CI 1.1–3.9, P = 0.031), working from home (aOR 2.3, 95% CI 1.0–5.3, P = 0.046) and increases in alcohol consumption (aOR 3.6, 95% CI 1.7–7.7, P = 0.023) were associated with increases in tobacco consumption.

Conclusion

A mixed picture was evident in terms of changes in consumption among current smokers and drinkers. Increased consumption was more commonly reported than reductions. Increased consumption was associated with psychological distress and socio-economic factors. Policies and services should consider a response to widening inequalities in harmful consumption.
Variants That Differentiate Wolf and Dog Populations Are Enriched in Regulatory Elements
Authors: Sahlén Pelin , Yanhu Liu , Xu Jinrui , Kubinyi Eniko , Wang Guo-Dong , Savolainen Peter
Published: April 2021

Research on the genetics of domestication most often focuses on the protein-coding exons. However, exons cover only a minor part (1–2%) of the canine genome, whereas functional mutations may be located also in regions beyond the exome, in regulatory regions. Therefore, a large proportion of phenotypical differences between dogs and wolves may remain genetically unexplained. In this study, we identified variants that have high allelic frequency differences (i.e., highly differentiated variants) between wolves and dogs across the canine genome and investigated the potential functionality. We found that the enrichment of highly differentiated variants was substantially higher in promoters than in exons and that such variants were enriched also in enhancers. Several enriched pathways were identified including oxytocin signaling, carbohydrate digestion and absorption, cancer risk, and facial and body features, many of which reflect phenotypes of potential importance during domestication, including phenotypes of the domestication syndrome. The results highlight the importance of regulatory mutations during dog domestication and motivate the functional annotation of the noncoding part of the canine genome.
GENE DIFFERENCES BETWEEN THE SEX RATIO AND STANDARD GENE ARRANGEMENTS OF THE X CHROMOSOME IN DROSOPHILA PERSIMILIS
Authors: Policansky David , Zouros E
Published: April 2021

The sibling species Drosophila pseudoobscura and D. persimilis each carry two gene arrangements in the right arm of the X chromosome; Standard (ST) and Sex Ratio (SR). The SR sequence of D. persimilis and the ST sequence of D. pseudoobscura have the same banding pattern. These cytologically identical arrangements carry different alleles at the esterase-5 (Est-5) and phosphoglucomutase-1 (Pgm-1) loci. All the alleles on the SR arrangement of D. persimilisare also present on the ST arrangement of that species, and the same allele was most common in all cases. However, the allele frequencies at the Pgm-1 locus are significantly different between the two arrangements. Within the ST arrangement of D. persimilis, the alleles at the Est-5 and Pgm-1 loci are in linkage equilibrium.
EPIDERMIS IS THE SITE OF ACTION OF TABBY (TA) IN THE MOUSE
Authors: Mayer Thomas C , Green Margaret C
Published: April 2021

The site of action of the sex-linked tabby (Ta) locus was analyzed by the technique of dermal-epidermal recombination grafting. Skin components from normal and tabby 14-day embryos were separated, recombined and grown 21 days in testes of histocompatible mice. Grafts of the combinations normal epidermis-normal dermis and normal epidermis-tabby dermis produced predominantly zig-zag hairs. Grafts of the combination tabby epidermis-normal dermis and tabby epidermis-tabby dermis produced hairs with a morphology similar to hairs found in tabby mice. We conclude from these results that the tabby locus acts within the epidermis, and has no effect on the dermis.
EVIDENCE FOR CO-DOMINANCE OF THE HOMOTHALLIC GENES, HMα/hmα AND HM
a/hm
a, IN SACCHAROMYCES YEASTS
Authors: Arima Kenji , Takano Isamu
Published: April 2021

To investigate the dominance and recessiveness of the homothallism genes, HMα/hmα and HMa/hma, for mating-type conversion, we constructed hybrids with various configurations of the homothallic genes by fusion of protoplasts prepared from haploid strains having identical mating types. Eight different combinations of the homothallic genes were tested for their function by observing the mating and sporulation abilities of the fusion products. With few exceptions, nonmating and sporogenous fusion products were obtained from the following combinations: α HO hmα  HMa + α ho hmα hma, α HO hmα HMa + α ho HMα hma, α HO hmα HMa + α ho HMα HMa, α HO HMα hma + a ho hmα hma, a HO HMα hma + a ho hmα HMa and a HO HMα hma + α ho HMα HMa. All the fusion products from the α HO hmα HMa + α ho hmα HMa and a HO HMα hma + a ho HMα hma combinations showed mating types identical to those of the respective haploid strains. These results clearly support the co-dominance of the HMα/hmα and HMa/hma alleles and indicate that the hmα allele has the same function as the HMa allele and that the hma allele has the same function as the HMα allele.
RELATIVE RATES AT WHICH DOMINANT-LETHAL MUTATIONS AND HERITABLE TRANSLOCATIONS ARE INDUCED BY ALKYLATING CHEMICALS IN POSTMEIOTIC MALE GERM CELLS OF MICE
Authors: Generoso Walderico M , Huff Sandra W , Cain Katherine T
Published: April 2021

There is a close relationship between the rates at which dominant lethal mutations and heritable translocations are induced by ethyl methanesulfonate (EMS) or triethylenemelamine (TEM) in male postmeiotic germ cells. This relationship does not hold for isopropyl methanesulfonate (IMS), which induced only negligible frequencies of heritable translocations at doses that induced high levels of dominant lethal mutations. Nor does IMS behave like EMS and TEM in the degree to which eggs of different stocks of females repair premutational lesions that are carried in the sperm—large differences between stocks for IMS treatment and small differences for EMS or TEM treatment. These dissimilarities between IMS and the other two alkylating chemicals are postulated to be attributable to differences in the types of lesions present at the time of repair activity and to whether or not chromosomal aberrations are already fixed prior to postfertilization pronuclear DNA synthesis.
CONTROL OF ENDOSPERM PROTEINS IN TRITICUM AESTIVUM (var. CHINESE SPRING) AND AEGILOPS UMBELLULATA BY HOMOEOLOGOUS GROUP 1 CHROMOSOMES
Authors: Brown John W S , Kemble Roger J , Law Colin N , Flavell Richard B
Published: April 2021

The genetic control of major wheat endosperm proteins by homoeologous group 1 chromosomes has been studied by two-dimensional polyacrylamide gel electrophoresis. The control of at least 15 distinct protein subunits or groups of protein subunits has been allocated to chromosomes 1A, 1B and 1D of Chinese Spring wheat from the analysis of grains of aneuploid genotypes. In addition, six protein subunits have been shown to be controlled by chromosome 1Cu of the related species, Aegilops umbellulata, from studies of wheat lines carrying disomic substitutions of 1Cu chromosomes. On the basis of protein subunit patterns, chromosome 1Cu is more closely related to chromosome ID of wheat than to chromosomes 1A or 1B.
GENE FLOW AND LIFE HISTORY PATTERNS
Authors: Endler John A
Published: April 2021

Dispersal distances overestimate the gene-flow scale l (the square-root of the mean squared distance travelled from birth to reproduction) when egg laying is concentrated early in dispersal and when there is mortality during dispersal. If egg laying follows a square-root normal distribution in time, as it does in several Drosophila species, then l is reduced to about 0.6 of that estimated from dispersal alone, unless egg laying is concentrated in a very brief period. If mortality is such that the half-life is earlier than the mean fecundity day, then l will be reduced still more relative to the dispersal estimate, and will be very sensitive to small changes in mortality. Overestimating l yields overestimates of the amount of selection needed to maintain geographic differences in gene frequencies. If mortality increases in suboptimal habitats, then the neighborhood size will be smaller in those areas, because increased mortality decreases l. This means that l is smallest, allowing the greatest differentiation and genetic innovation, precisely where it is most needed. This lends support to WRIGHT'S shifting balance hypothesis. If l is adjusted to local conditions, then we do not necessarily expect a positive relationship between environmental and genetic heterogeneity. Data from Drosophila pseudoobscura are used to make the models realistic, and it is shown that l depends on the distances among traps or breeding sites. It is therefore essential to know the geometry of breeding sites and the life history parameters to estimate l.
SELECTION OF lys2 MUTANTS OF THE YEAST SACCHAROMYCES CEREVISIAE BY THE UTILIZATION OF α-AMINOADIPATE
Authors: Chattoo Bharat B , Sherman Fred , Azubalis Dalia A , Fjellstedt Thorsten A , Mehnert David , Ogur Maurice
Published: April 2021

Normal strains of Saccharomyces cereuisiae do not use α-aminoadipate as a principal nitrogen source. However, α-aminoadipate is utilized as a nitrogen source by lys2 and lys5 strains having complete or partial deficiencies of α-aminoadipate reductase and, to a limited extent, by heterozygous lys2/ + strains. Lys2 mutants were conveniently selected on media containing α-aminoadipate as a nitrogen source, lysine, and other supplements to furnish other possible auxotrophic requirements. The lys2 mutations were obtained in a variety of laboratory strains containing other markers, including other lysine mutations. In addition to the predominant class of lys2 mutants, low frequencies of lys5 mutants and mutants not having any obvious lysine requirement were recovered on α-aminoadipate medium. The mutants not requiring lysine appeared to have mutations at the lys2 locus that caused partial deficiencies of a-aminoadipate reductase. Such partial deficiencies are believed to be sufficiently permissive to allow lysine biosynthesis, but sufficiently restrictive to allow for the utilization of α-aminoadipate. Although it is unknown why partial or complete deficiencies of α-aminoadipate reductase cause utilization of α-aminoadipate as a principal nitrogen source, the use of α-aminoadipate medium has considerable utility as a selective medium for lys2 and lys5 mutants.
GENETIC AND PHENOTYPIC CHARACTERIZATION OF ROLLER MUTANTS OF CAENORHABDITIS ELEGANS
Authors: Cox George N , Laufer John S , Kusch Meredith , Edgar Robert S
Published: April 2021

Eighty-eight mutants of C. elegans that display a roller phenotype (a helically twisted body) have been isolated and characterized genetically and phenotypically. The mutations are located in 14 different genes. Most genes contain a number of alleles. Their distribution among the chromosomes appears nonrandom, with seven of the genes being located on linkage group 11, some very closely linked. The phenotypes of the mutants suggest that there are five different classes of genes, each class representing a set of similar phenotypic effects: Left Roller (four genes), Right Roller (one gene), Left Squat (one gene), Right Squat (two genes) and Left Dumpy Roller (six genes). The classes of mutants differ with respect to a number of characteristics that include the developmental stages affected and the types of aberrations observed in cuticle structure. A variety of gene interactions were found, arguing that these genes are involved in a common developmental process. The presence of alterations in cuticle morphology strongly suggests that these genes are active in the formation of the nematode cuticle.
GENETIC ANALYSIS OF THE ANTENNAPEDIA GENE COMPLEX (ANT-C) AND ADJACENT CHROMOSOMAL REGIONS OF DROSOPHILA MELANOGASTER. I. POLYTENE CHROMOSOME SEGMENTS 84B-D
Authors: Lewis R A , Kaufman T C , Denell R E , Tallerico P
Published: April 2021

A deficiency spanning section 84B-D of the proximal right arm of chromosome 3 of Drosophila melanogaster has been utilized as a screen for mutations that aid in the genetic dissection of this developmentally interesting region.——Ninety-two mutations have been recovered, of which 12 have been localized by deficiency and complementation mapping to the 84B1,2 doublet, the site of the Antennapedia complex (ANT-C). This has permitted a more precise description of the genetic organization of this complex locus.——A collection of 31 mutations that reside in 84Cl-D2 displays an intricate circular complementation pattern, characterized by two clusters of mutations that exhibit semi-lethality, negative complementation and temperature sensitivity. Mutations affecting seven additional functional groups within the 84B-D region were also recovered.
ANALYZING GENE-FREQUENCY DATA WHEN THE EFFECTIVE POPULATION SIZE IS FINITE
Authors: Wilson Susan R
Published: April 2021

The statistical methods used by SCHAFFER, YARDLEY and ANDERSON (1977) and by GIBSON et al. (1979) to analyze the variation in allele frequencies in two common types of experimental procedure, where the effective population size is finite, are extended to a more general situation involving a greater range of experiments. The analysis developed is more sensitive in detecting changes in allele frequency due to both fluctuating and balancing selection, as well as to directional selection. The error involved in many studies due to ignoring the effective population size structure would appear to be large. The range of hypotheses that can be considered may be increased as well. Finally, the method of determining bounds for the effective population size, when a particular genetic model is known to hold for a data set, is also outlined.
THE IMPACT OF RANDOM AND LINEAL FISSION ON THE GENETIC DIVERGENCE OF SMALL HUMAN GROUPS: A CASE STUDY AMONG THE YANOMAMA
Authors: Smouse Peter E , Vitzthum Virginia J , Neel James V
Published: April 2021

Most of the genetic divergence that currently separates populations of Homo sapiens must have arisen during that long period when the local village (or band) was the basic unit of biological evolution. Studies of tribally intact Amerindian groups exhibiting such small-group organization have demonstrated marked genetic divergence between nearby villages. Some of this genetic radiation can be attributed to the effects of random genetic drift over time within these small demes. Some of it, however, might be better ascribed to the consequences of nonrandom genetic assortment at the time of village fission, a recurring event for such groups. Even random genetic assortment at the time of fission would lead to some genetic divergence, due to the finite size of the parent gene pool. We term the genetic consequences of random assortment the random fission effect. Routinely, village fission occurs along family lines, leading to even greater genetic divergence between the daughter villages. We use the term lineal fission effect to describe the genetic consequences of nonrandom assortment and contrast these results with those derived from random assortment.——A formal treatment of random and lineal fission effects is developed, first for the single-locus case, then for the multiple-locus extension. Using this formulation, three Yanomama fission events were examined. Fission in the Yanomama often involves a great deal of mutual hostility between the two factions, so that subsequent gene flow between the two daughter villages is minimal. The first two examples are typical of the Yanomama behavior norm, and are accompanied by a minimum of subsequent gene flow between the daughter villages. In these two cases, the observed divergence values are very large and are also very unlikely under random fission. The lineal fission effect is pronounced. The net impact of lineal fission is to reduce the effective size of the village at the time of fission by a factor of four, relative to expectation from random fission. The third example, however, involved an unusually amicable split of a village, followed by free genetic exchange between the fission products. This "friendly fission" yields an observed divergence value not much in excess of the expectation from random fission.—The long-term consequences of such fission bottlenecks in effective population size are discussed for both intra- and inter-tribal genetic diversity. It appears that the rate of genetic divergence for tribal and subtribal groups may have been somewhat greater than would be expected from classical drift arguments.
MUTANTS OF YEAST DEFECTIVE IN SUCROSE UTILIZATION
Authors: Carlson Marian , Osmond Barbara C , Botstein David
Published: April 2021

Utilization of sucrose as a source of carbon and energy in yeast (Saccharomyces) is controlled by the classical SUC genes, which confer the ability to produce the sucrose-degrading enzyme invertase (Mortimer and Hawthorne 1969). Mutants of S. cerevisiae strain S288C (SUC2  +) unable to grow anaerobically on sucrose, but still able to use glucose, were isolated. Two major complementation groups were identified: twenty-four recessive mutations at the SUC2 locus (suc2  -); and five recessive mutations defining a new locus, SNF1 (for sucrose nonfermenting), essential for sucrose utilization. Two minor complementation groups, each comprising a single member with a leaky sucrose-nonfermenting phenotype, were also identified. The suc2 mutations isolated include four suppressible amber mutations and five mutations apparently exhibiting intragenic complementation; complementation analysis and mitotic mapping studies indicated that all of the suc2 mutations are alleles of a single gene. These results suggest that SUC2 encodes a protein, probably a dimer or multimer. No invertase activity was detected in suc2 mutants.—The SNF1 locus is not tightly linked to SUC2. The snf1 mutations were found to be pleiotropic, preventing sucrose utilization by SUC2  + and SUC7  + strains, and also preventing utilization of galactose, maltose and several nonfermentable carbon sources. Although snf1 mutants thus display a petite phenotype, classic petite mutations do not interfere with utilization of sucrose, galactose or maltose. A common feature of all the carbon utilization systems affected by SNF1 is that all are regulated by glucose repression. The snf1 mutants were found to produce the constitutive nonglycosylated form of invertase, but failed to produce the glucose-repressible, glycosylated, secreted invertase. This failure cannot be attributed to a general defect in production of glycosylated and secreted proteins because synthesis of acid phosphatase, a glycosylated secreted protein not subject to glucose repression, was not affected by snf1 mutations. These findings suggest that the SNF1 locus is involved in the regulation of gene expression by glucose repression.
In-Depth Analyses of the Effects of a Diet and Resistance Exercise Intervention in Older Adults: Who Benefits Most From ProMuscle in Practice?
Authors: Dorhout Berber G , Doets Esmée L , van Dongen Ellen J I , de Groot Lisette C P G M , Haveman-Nies Annemien
Published: April 2021

Background

The ProMuscle in Practice intervention, comprising resistance exercise and an increased protein intake, was effective in improving muscle strength, lean body mass, and physical functioning in older adults aged 65 years and older (N = 168). However, a heterogeneous response to such interventions is common. Therefore, we explored the differences in responsiveness to the intervention in subgroups based on demographic characteristics and mobility-impairing disorders.

Method

Multiple regression analyses were performed to study mean changes between baseline and 12 weeks on the Short Physical Performance Battery, chair rise test, lean body mass, knee extension strength, leg press strength, and leg extension strength. The interaction term Treatment × Subgroup was included to study differences in effects between subgroups. Subgroups comprised age (≤75 vs >75 years), sex (men vs women), presence of frailty, presence of sarcopenia, and presence of osteoarthritis.

Results

A significant interaction effect including age was found on lean body mass (β = −0.8; 95% CI: −1.5, −0.2), favoring participants aged 75 years and younger. A significant interaction effect including sex was found on leg press strength (β = 15.5; 95% CI: 0.6, 30.3), favoring women. Participants with or without frailty, sarcopenia, or osteoarthritis responded equally to the intervention in terms of absolute effects.

Conclusions

Participants aged 75 years and younger and women benefited to a great extent from the intervention, as they improved significantly on nearly every outcome. Effects in participants with and without a mobility-impairing disorder were comparable, indicating that the intervention is suitable for both groups.
Body Composition by Computed Tomography vs Dual-Energy X-ray Absorptiometry: Long-Term Prediction of All-Cause Mortality in the Health ABC Cohort
Authors: Farsijani Samaneh , Xue Lingshu , Boudreau Robert M , Santanasto Adam J , Kritchevsky Stephen B , Newman Anne B
Published: April 2021

Background

Body composition assessment by computed tomography (CT) predicts health outcomes in diverse populations. However, its performance in predicting mortality has not been directly compared to dual-energy X-ray absorptiometry (DXA). Additionally, the association between different body compartments and mortality, acknowledging the compositional nature of the human body, is not well studied. Compositional data analysis, which is applied to multivariate proportion-type data set, may help to account for the interrelationships of body compartments by constructing log ratios of components. Here, we determined the associations of baseline CT-based measures of mid-thigh cross-sectional areas versus DXA measures of body composition with all-cause mortality in the Health ABC cohort, using both traditional (individual body compartments) and compositional data analysis (using ratios of body compartments) approaches.

Methods

The Health ABC study assessed body composition in 2911 older adults in 1996–1997. We investigated the individual and ratios of (by compositional analysis) body compartments assessed by DXA (lean, fat, and bone masses) and CT (muscle, subcutaneous fat area, intermuscular fat, and bone) on mortality, using Cox proportional hazard models.

Results

Lower baseline muscle area by CT (hazard ratio [HR]men = 0.56; 95% confidence interval [95% CI]: 0.48–0.67, HRwomen = 0.60; 95% CI: 0.48–0.74) and fat mass by DXA (HRmen = 0.48; 95% CI: 0.24–0.95) were predictors of mortality in traditional Cox regression analysis. Consistently, compositional data analysis revealed that lower muscle area versus IMF, muscle area versus bone area, and lower fat mass versus lean mass were associated with higher mortality in both sexes.

Conclusion

Both CT measure of muscle area and DXA fat mass (either individually or relative to other body compartments) were strong predictors of mortality in both sexes in a community research setting.
Anti-Tumor Necrosis Factor-Alpha Withdrawal in Children With Inflammatory Bowel Disease in Endoscopic and Histologic Remission
Authors: Scarallo Luca , Bolasco Giulia , Barp Jacopo , Bianconi Martina , di Paola Monica , Di Toma Michele , Naldini Sara , Paci Monica , Renzo Sara , Labriola Flavio , De Masi Salvatore , Alvisi Patrizia , Lionetti Paolo
Published: April 2021

Background

The aim of the present study was to investigate outcomes of anti-TNF-alpha (ATA) withdrawal in selected pediatric patients with inflammatory bowel disease who achieved clinical remission and mucosal and histological healing (MH and HH).

Methods

A retrospective analysis was performed on children and adolescents affected by Crohn disease (CD) and ulcerative colitis (UC) who were followed up at 2 tertiary referral centers from 2008 through 2018. The main outcome measure was clinical relapse rates after ATA withdrawal.

Results

One hundred seventy patients received scheduled ATA treatment; 78 patients with CD and 56 patients with UC underwent endoscopic reassessment. We found that MH was achieved by 32 patients with CD (41%) and 30 patients with UC (53.6%); 26 patients with CD (33.3%) and 22 patients with UC (39.3%) achieved HH. The ATA treatment was suspended in 45 patients, 24 affected by CD and 21 by UC, who all achieved concurrently complete MH (Simplified Endoscopic Score for CD, 0; Mayo score, 0, respectively) and HH. All the patients who suspended ATA shifted to an immunomodulatory agent or mesalazine. In contrast, 17 patients, 8 with CD and 9 with UC, continued ATA because of growth needs, the persistence of slight endoscopic lesions, and/or microscopic inflammation. Thirteen out of 24 patients with CD who suspended ATA experienced disease relapse after a median follow-up time of 29 months, whereas no recurrence was observed among the 9 patients with CD who continued treatment (P = 0.05). Among the patients with UC, there were no significant differences in relapse-free survival among those who discontinued ATA and those who did not suspend treatment (P = 0.718).

Conclusions

Despite the application of rigid selection criteria, ATA cessation remains inadvisable in CD. In contrast, in UC, the concurrent achievement of MH and HH may represent promising selection criteria to identify patients in whom treatment withdrawal is feasible.