Towards a Typology of Learning Workers: Latent Class Analysis of Adult Education Participation in the United States

This study identifies a typology of learning workers by investigating profiles of individuals participating in adult education. Using latent class analysis, we examined four classes and their associations with covariates

Učinci prenatalne i postnatalne izloženosti perfluorooktanskoj kiselini na ekspresiju glavnih gena povezanih s reprodukcijom u mišjem hipotalamusu i spolnim žlijezdama

Perfluorooctanoic acid (PFOA), a ubiquitous environmental pollutant reported to be an endocrine disruptor, is used in many industrial and consumer products. Although the adverse effects of PFOA on the reproductive health of animals and humans have been widely reported, most studies have focused on assessing the anatomical features and conventional histology of adult gonads. Therefore, the molecular mechanisms activated in the hypothalamus and gonads following PFOA exposure during the pre- and postnatal periods are not clear. This study used a mouse model to evaluate the effects of PFOA exposure on the alteration of molecular mechanisms in the hypothalamus and gonads during the prenatal and postpartum periods. Changes in gene and protein expression following PFOA exposure were evaluated by quantitative polymerase chain reaction and Western blotting, respectively. Kisspeptin 1 and gonadotropin-releasing hormone expression in the hypothalamus of female and male mouse pups was significantly decreased. Additionally, Cyp17a1 expression was upregulated in male offspring testes, while Cyp17a1 and Cyp19a1 expression was downregulated in female offspring ovaries. Changes at the molecular level due to PFOA exposure in the early stages of development did not show sex-related differences in the hypothalamus; however, such differences were confirmed in the gonads. These results could be used as basic data to study the molecular mechanisms underlying the reproductive dysfunction caused by PFOA exposure in the early stages of embryonic development.Perfluorooktanska kiselina (PFOA) sveprisutna je onečišćujuća tvar za okoliš, za koju je zabilježeno da uzrokuje i endokrinopatije, a upotrebljava se u mnogim industrijskim proizvodima. Bez obzira na poznate i zabilježene nuspojave PFOA-e na reproduktivno zdravlje životinja i ljudi, većina se istraživanja usredotočuje na procjenu anatomskih histoloških značajki u spolnim žlijezdama odraslih jedinki. Molekularni mehanizmi koji se aktiviraju u hipotalamusu i spolnim žlijezdama nakon izlaganja PFOA-i stoga nisu razjašnjeni. U ovom je istraživanju upotrijebljen mišji model za procjenu učinaka izlaganja PFOA-i na promjenu molekularnih mehanizama u hipotalamusu i spolnim žlijezdama za vrijeme prijeporođajnog i poslijeporođajnog razdoblja. Promjene u ekspresiji gena i proteina nakon izloženosti PFOA-i analizirane su kvantitativnom PCR metodom i metodom Western blotting. Ekspresija kispeptina 1 i hormona koji oslobađa gonadotropin u hipotalamusu ženske i muške mladunčadi bila je znakovito smanjena. Osim toga ekpresija Cyp17a1 bila je pojačana u testisima muških potomaka, dok je ekspresija Cyp17a1 i Cyp19a1 u jajnicima ženskih potomaka bila smanjena. Kod promjena na molekularnoj razini u hipotalamusu u ranim razvojnim stadijima nije bilo razlike među spolovima, dok je kod promjena u spolnim žlijezdama povrđena razlika među spolovima. Rezultati ovog istraživanja mogli bi biti korisni kao osnovni podaci u proučavanju molekularnih mehanizama podležeće reproduktivne disfunkcije uzrokovane izloženošću PFOA-i u ranim stadijima embrionalnog razvoja

Characterization of GDP-mannose Pyrophosphorylase from Escherichia Coli O157:H7 EDL933 and Its Broad Substrate Specificity

GDP-mannose pyrophosphorylase gene (ManC) of Escherichia coli (E. coli) O157 was cloned and expressed as a highly soluble protein in E. coli BL21 (DE3). The enzyme was subsequently purified using hydrophobic and ion exchange chromatographies. ManC showed very broad substrate specificities for four nucleotides and various hexose-1-phosphates, yielding ADP-mannose, CDP-mannose, UDP-mannose, GDP-mannose, GDP-glucose and GDP-2-deoxy-glucose

Computational models for the ultimate strength analysis of steel stiffened plate structures under monotonic and cyclic compressive loadings

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New parameterization of air-sea exchange coefficients and its impact on intensity prediction under major tropical cyclones

Understanding and quantifying air-sea exchanges of enthalpy and momentum fluxes are crucial for the advanced prediction of tropical cyclone (TC) intensity. Here, we present a new parameterization of air-sea fluxes at extreme wind speeds from 40 m s−1 to 75 m s−1, which covers the range of major TCs. Our approach assumes that the TC can reach its maximum potential intensity (MPI) if there are no influences of external forces such as vertical wind shear or other environmental constraints.This method can estimate the ratio of the enthalpy and momentum exchange coefficient (Ck/Cd) under the most intense TCs without direct flux measurements. The estimation showed that Ck/Cd increases with wind speed at extreme winds above 40 m s−1. Two types of surface layer schemes of the Hurricane Weather and Research Forecast (HWRF) were designed based on the wind speed dependency of the Ck/Cd found at high winds: (i) an increase of Ck/Cd based on decreasing Cd (Cd_DC) and (ii) an increase of Ck/Cd based on increasing Ck (Ck_IC). The modified surface layer schemes were compared to the original HWRF scheme (using nearly fixed Cd and Ck at extreme winds; CTRL) through idealized experiments and real-case predictions. The idealized experiments showed that Cd_DC reduced frictional dissipation in the air-sea interface as well as significantly reduced sea surface cooling, making the TC stronger than other schemes. As a result, Cd_DC reduced the mean absolute error and negative bias by 15.0% (21.0%) and 19.1% (32.0%), respectively, for all lead times of Hurricane Irma in 2017 (Typhoon Mangkhut in 2018) compared to CTRL. This result suggests that new parameterization of Ck/Cd with decreasing Cd at high winds can help improve TC intensity prediction, which currently suffers from underestimating the intensity of the strongest TCs

An Index to Better Estimate Tropical Cyclone Intensity Change in the Western North Pacific

A revised predictor called the net energy gain rate (NGR) is suggested by considering wind dependent drag coefficient based on the existing maximum potential intensity theory. A series of wind speed dependent NGR, known as NGR‐w, is calculated based on pre‐tropical cyclone (TC) averaged ocean temperatures from the surface down to 120 m (at 10‐m intervals) to include the TC‐induced vertical mixing for 13 years (2004–2016) in the western North Pacific. It turns out that the NGR50‐w (NGR‐w based on temperature averaged over top 50 m) has the highest correlation with 24‐h TC intensity change compared with the commonly used sea surface temperature‐based intensification potential (POT), depth‐averaged temperature‐based POT (POTDAT), and constant drag coefficient in the NGR. To demonstrate the effectiveness of the NGR50‐w, we designed and conducted experiments for training (2004–2014) and testing (2015–2016). The model with the NGR50‐w shows greater skill than the model with POTDAT or POT by reducing prediction errors by about 16%

Electrical spin injection and accumulation in CoFe/MgO/Ge contacts at room temperature

We first report the all-electrical spin injection and detection in CoFe/MgO/moderately doped n-Ge contact at room temperature (RT), employing threeterminal Hanle measurements. A sizable spin signal of ~170 k{\Omega} {\mu}m^2 has been observed at RT, and the analysis using a single-step tunneling model gives a spin lifetime of ~120 ps and a spin diffusion length of ~683 nm in Ge. The observed spin signal shows asymmetric bias and temperature dependences which are strongly related to the asymmetry of the tunneling process.Comment: 28 pages, 5 figure