bluuebunny/crossref_metadata_2025 huggingface dataset:
Basal and FSH‐Stimulated Steady State Levels of SGP‐2, α2‐Macroglobulin, and Testibumin in Culture Media of Rat Seminiferous Tubules at Defined Stages of the Epithelial Cycle
Authors: KANGASNIEMI MARKO , CHENG C. YAN , TOPPARI JORMA , GRIMA JOSEPHINE , STAHLER MICHAEL , BARDIN C. WAYNE , PARVINEN MARTTI
Published: October 2023

ABSTRACT: Production of several proteins by rat Sertoli cells is dependent on the stage of the cycle of the seminiferous epithelium. The authors have determined steady state levels and follicle‐stimulating hormone responsiveness of three Sertoli cell products in culture media of rat seminiferous tubule segments at different stages of the epithelial cycle: SGP‐2 (sulfated glycoprotein‐2), α2‐macroglobulin, and testibumin. Basal SGP‐2 levels were twofold higher in stages VII through VIII compared with stages XIII to I to VI (P < 0.05). Highest basal α2‐macroglobulin levels were found in stages II through VIII; this was about 35% greater than in stages XIII through I of the cycle (P < 0.05). Basal testibumin levels were twofold higher in stages II through VI compared with stages IX through XII of the cycle. Follicle‐stimulating hormone had no effect on SGP‐2, but by contrast it (50 mg/L) increased the level of α2‐macroglobulin significantly (P < 0.05) in stages XIII through I. Follicle‐stimulating hormone treatment (10 mg/L) elevated testibumin levels at each stage‐pool by about 40% (P < 0.05). The current results using staged tubular segments in vitro demonstrate cyclic basal steady‐state levels of the three proteins along the seminiferous tubules and follicle‐stimulating hormone regulation of α2‐macroglobulin and testibumin.
The Lack of Effect of Tumor Necrosis Factor‐Alpha, Interleukin‐1‐Alpha, and Interferon‐Gamma on Human Sperm Motility In Vitro
Authors: HANEY A.F. , HUGHES SUSAN F. , WEINBERG J. BRICE
Published: October 2023

ABSTRACT: Whether cytokines present in human peritoneal fluid reduce sperm motility, and thus contribute to infertility, is investigated. The human recombinant cytokines, tumor necrosis factor‐alpha, interleukin‐1‐alpha, and interferon‐gamma, were incubated with motile human sperm obtained from fertile men and separated by the swim‐up technique. These cytokines, alone or in combination, in higher doses than those observed in vivo (≥25,000 U/ml), did not alter the percentage of motile sperm after 90 minutes, 24 hours, and 48 hours under standard culture conditions. Similarly, penetration of a column of bovine cervical mucus was unchanged after preincubation of the sperm with individual cytokines or combinations of several cytokines for 24 hours. In contrast to those given in previous reports, these data do not support a direct effect of tumor necrosis factor‐alpha, interleukin‐1‐alpha, or interferon‐gamma on sperm motility, and suggest that other soluble factors are responsible for the observed effects of peritoneal fluid on sperm motility in vitro.
Heterogeneity of Adult Mouse Leydig Cells with Different Buoyant Densities
Authors: MENDIS‐HANDAGAMA S. M. L. CHAMINDRANI , de KRETSER DAVID M.
Published: October 2023

ABSTRACT: The authors investigated the morphologic characteristics and human chorionic gonadotrophin (hCG)‐stimulated testosterone production of adult mouse Leydig cells in vitro, which have different buoyant densities. Leydig cells from five testes of Swiss outbred male mice (15 weeks old) were isolated and purified by mechanical dispersion followed by density gradient centrifugation using Percoll. Two groups of Leydig cells were obtained with different buoyant densities: group 1 had densities of 1.0667 to 1.0515 g/cm3 and group 2 had densities of 1.0514 to 1.0366 g/cm3. In vitro testosterone production of these Leydig cells, in response to different doses of hCG (0, 5, 25,125, 625, and 3125 pg/mL), was determined by radioimmunoassay. Leydig cells were fixed and processed for electron microscopic stereology to quantify the organelles by volumes and surface area. In Leydig cells of Group 1, testosterone production per cell in vitro in response to 0 and 5 pg/mL hCG was not significantly different (P > 0.05). Increases in the dose up to 25 pg/mL produced a significant increase (P < 0.05) in testosterone production, although hCG doses of 125 and 625 pg/mL did not produce further increases in testosterone levels. However, 3125 pg/mL hCG further elevated the testosterone production by those Leydig cells with high buoyant density. In Leydig cells in group 2, the patterns of testosterone production in response to hCG doses of 0, 5, and 25 pg/mL were similar to those of Leydig cells in group 1. Those Leydig cells with low buoyant density, however, were unable to stimulate further testosterone production by an hCG dose of 3125 pg/mL. Comparison of testosterone production per Leydig cell between the two groups with different doses of hCG showed that Leydig cells in group 2 (lower buoyant density) showed a lower value than those in group 1 (higher buoyant density) for all hCG doses studied. Statistical significance (P < 0.05), however, was observed only with the hCG dose of 3125 pg/mL. These results demonstrated that Leydig cells with different buoyant densities were different in their sensitivity to hCG stimulation in vitro. Leydig cells in groups 1 and 2 were also different in their organelle composition, the most prominent feature being the differences in their lipid contents. Leydig cells with low buoyant density (group 2) were rich in lipid droplets, and Leydig cells with high buoyant density contained less lipid. Lipid‐rich Leydig cells with reduced testosterone production contained reduced surface area of smooth endoplasmic reticulum and membrane whorls, features characteristic to less differentiated Leydig cells in mice. Based on these results, the authors conclude that adult mouse Leydig cells exist as a heterogeneous population. Leydig cells with low buoyant density were less differentiated than those with high buoyant density with respect to their ultrastructure and their sensitivity to hCG stimulation in vitro.
Lipid Peroxidation and Antioxidant Enzyme Activities in the Rat Testis after Cigarette Smoke Inhalation or Administration of Polychlorinated Biphenyls or Polychlorinated Naphthalenes
Authors: PELTOLA VILLE , MÄNTYLÄ EERO , HUHTANIEMI ILPO , AHOTUPA MARKKU
Published: October 2023

Lipid peroxidation products and antioxidant enzyme activities were studied in the rat testis following exposures to cigarette smoke, polychlorinated biphenyls (PCBs), or polychlorinated naphthalenes (PCNs). Three hours after a single 1‐hour period of smoke inhalation, the levels of fluorescent chromolipids and thiobarbituric acid‐reactive species (TBARS) were markedly increased in the testis (+49%, P < 0.01, and +43%, P < 0.05, respectively). Twelve hours after daily smoking for 1 hour, for 1, 5, or 10 days, such an increase was not found. Activities of the antioxidant enzymes superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH‐Px), glutathione transferase (GSH‐Tr), or hexose monophosphate shunt (HMS) were not affected immediately, 3 hours, or 12 hours after a single smoking session. Twelve hours after smoking for 5 days, the activity of catalase was decreased (‐16%, P < 0.05). Smoking exposures had no consistent effects on serum follicle‐stimulating hormone (FSH), luteinizing hormone (LH), or testosterone concentrations. Single i.p. injections of PCB or PCN mixtures resulted in decreases in testicular SOD activity 1 day after the exposures (‐14%, P < 0.05, and −51%, P < 0.01, respectively). Catalase activity also decreased after both exposures (−30 to −42%, P < 0.05, at days 1–7 after PCB exposure, and −37 to −43%, P < 0.05, at days 3–7 after PCN exposure). Ninety days after the PCN exposure, activities of GSH‐Px and GSH‐Tr were decreased in the testis (−20%, P < 0.05, and −26%, P < 0.05, respectively). The only statistically significant change in lipid peroxidation measurements in the testes of PCB‐ or PCN‐treated rats was a decrease in TBARS by 13% (P < 0.01) 1 day after PCN exposure. The main findings of this study were the increase in lipid peroxidation in the rat testis after cigarette smoke inhalation and the impairment of the function of the enzymatic antioxidant defense after exposures to PCBs or PCNs. These results suggest that free radical‐dependent mechanisms may play an important role in the testicular toxicity of environmental chemicals.
The Effect of Vasoactive Intestinal Polypeptide (VIP) on Rabbit Cavernosal Smooth Muscle Contractility
Authors: KIM YOUNG CHAN , CHOI HYUNG KI , AHN YOUNG SOO , KIM KYUNG HWAN , HAGEN PER‐OTTO , CARSON CULLEY C.
Published: October 2023

ABSTRACT: Vasoactive intestinal polypeptide (VIP) has emerged as a possible candidate for a nonadrenergic, noncholinergic inhibitory neurotransmitter in penile erection. In this study, the effect of VIP and Its relationship to the adrenergic and cholinergic mechanisms were examined using isolated corpus cavemosal strips from the rabbit penis. The mechanism of action of VIP on corporal relaxation was investigated with respect to the activation of cyclic GMP and the mobilIzation of calcium and potassium ions. VIP caused a dose‐dependent relaxation of the cavemosal strip. Pretreatment with VIP had no effect on the contraction induced by norepinephrine, phenylephrine, and clonidine. VIP had no synergistic effect on the relaxation produced by acetylcholine or isoproterenol. Neither atropine nor propranolol had any blocking effect on the VIP‐induced relaxation. Methylene blue decreased the VIP‐Induced relaxation of the cavemosal strip. VIP had no effect on the contraction induced by KCI at either 20 or 80mM. In calcium‐free high‐potassium physiologic salt solution, VIP inhibited the calcium‐induced contraction. These results suggests that the mechanism of action of VIP is not mediated through classical adrenergic and cholinergic neurotransmission on rabbit cavernosal strips, but that VIP may exert its action by the activation of cyclic GMP, which may be associated, in part, with the inhibition of calcium influx.
Phosphatidylcholine Enhances the Acrosomal Responsiveness of Human Sperm
Authors: CROSS NICHOLAS L.
Published: October 2023

ABSTRACT: Supplementing bovine serum albumin‐containing medium with phosphatidylcholine (PC) accelerated the in vitro development of human sperm acrosomal responsiveness. Responsiveness was assessed by exposing the sperm to progesterone. The maximum effect was produced by incubation with 100 μ/ml, which resulted in 40% (23–56%) (mean, 95% confidence limits) of the sperm becoming responsive to progesterone at 24 hours, compared to 23% (10–40%) of control sperm. Enhancement was apparent after as little as 6 hours of incubation in vitro, and the number of responsive sperm was still increasing at the last time point tested (30 hours). PC had no apparent ill effects; it did not alter the percentage of motile sperm or the percentage of sperm stained with the supravital stain, Hoechst 33258. Enhanced responsiveness required prolonged incubation in PC, because PC was not effective when it was only applied at the same time as progesterone. Lysophosphatidyicholine did not enhance acrosomal responsiveness when used at concentrations from 10 ng/ml to 100 μg/ml, indicating that the effect of PC was not due to trace amounts of lysophosphatidylcholine. PC also increased the response of sperm to the Ca2+/H+‐exchanging ionophore, ionomycin, suggesting that PC modifies an event that is coincident with or subsequent to the rise in intracellular free Ca2+ that is triggered by progesterone.
Two‐Dimensional Electrophoretic Profile of Human Sperm Membrane Proteins
Authors: XU CHONG , RIGNEY DAVID R. , ANDERSON DEBORAH J.
Published: October 2023

ABSTRACT: The purpose of this study was to characterize highly enriched human spermatozoa membrane proteins by two‐dimensional electrophoresis and computer image analysis. Sperm membrane proteins were extracted by detergent solubilization from three different preparations: 1) washed semen cells following centrifugation and three wash steps in Ham's F‐10 medium (the standard sperm preparation, which is contaminated with seminal immature germ cells, white blood cells, and acellular material), 2) the motile sperm fraction following centrifugation of diluted semen cells through a Percoll density gradient to enrich (>98%) the viable mature sperm population, and 3) sperm membrane vesicles isolated from Percoll‐purified motile mature sperm by nitrogen cavitation followed by differential centrifugation. The two‐dimensional gel profiles of extracts of washed semen cells and motile spermatozoa contained more than 600 protein spots between pH 4 and 7 and apparent molecular mass ranging from 7.9 to 93.5 kDa. Only 73% of the major proteins in these two samples matched by computer image analysis. The highly enriched sperm membrane vesicle extract showed a much simpler protein pattern, with only 64 major protein spots, 61 of which could be matched with proteins detected in extracts from purified motile sperm.

The isoelectric point and molecular weight coordinates of these major human sperm membrane proteins could serve as a foundation for systematic isolation and further characterization of human sperm antigens for studies of mechanisms of fertilization and the development of contraceptive vaccines.
Volume Effect of Nerve Hydrodissection for Carpal Tunnel Syndrome
Authors: Huang Chien‐Yao , Lai Chia‐Ying , Reeves Kenneth Dean , Lam King Hei Stanley , Li Tsung‐Ying , Cheng Chin‐I , Wu Yung‐Tsan
Published: October 2023

Objectives

This study compared ultrasound‐guided nerve hydrodissection (HD) outcomes using two commonly used injectate volumes (10 and 5 mL) of normal saline to explore if there is a volume effect of HD for patients with moderate carpal tunnel syndrome (CTS).

Methods

Twenty‐four participants were randomly assigned to treatment with HD using ultrasound‐guidance and either 10 mL or 5 mL of normal saline (HD‐10 and HD‐5 groups respectively). Our primary outcome measures were the change scores of the two subscales of the Boston Carpal Tunnel Syndrome Questionnaire: The Symptom Severity Scale (SSS) and Functional Status Scale (FSS). We conducted a one‐way repeated analysis of variance for 3 time points (4, 12, and 24 weeks) for both SSS and FSS, respectively, for change scores from time 0, and percentage change from time 0.

Results

All participants (n = 12 per group) completed the study. From 0 to 24 weeks the HD‐10 group outperformed the HD‐5 group for improvement in SSS (median ± IQR; −0.8 ± 0.4 versus −0.5 ± 0.5; P = .024) and FSS scores (mean ± SD; −0.8 ± 0.2 versus −0.5 ± 0.5; P = .011). The HD‐10 group improvement in FSS subtest significantly exceeded the MCID percentage‐change‐based threshold of 27% (34%; P = .039).

Conclusions

Despite the limitations of small study size, a largely inert injectate, and a single injection approach, these findings in favor of the 10 mL group suggest that the volume used for ultrasound‐guided HD in moderate CTS matters, and a higher volume is more effective.
Dam‐induced riverbed degradation in the Saskatchewan River Delta
Authors: Li Lin , Sabokruhie Pouya , Lindenschmidt Karl‐Erich
Published: October 2023

River deltas formed by the uninterrupted flow of water carrying sediments and nutrients provide many benefits to humans, including natural resources (e.g., water, aquatic, and terrestrial species) and fertile land. However, the sustainability of river deltas is threatened by large hydraulic infrastructure (e.g., upstream dams), other human activities, and climate change. For example, the Saskatchewan River Delta in Northern Canada is threatened because dams upstream interrupt the sediment transport, resulting in declining sediment levels. The lack of sediment affects the ecology and environment of the delta. This paper will address how dam operation can be adapted to decrease erosion and maintain hydrological, ecological, and environmental outcomes from human activities in the Saskatchewan River Basin, especially the South Saskatchewan River and the river delta. The cross‐sectional data along the Saskatchewan River below the E.B. Campbell Dam were considered for unsteady flow simulations via HEC‐RAS. Insufficient sediment reaches the Saskatchewan River Delta, resulting in ecological changes. The purpose is to give decision‐makers or related stakeholders insight into developing strategies for reducing erosion, replenishing moisture, and restoring sediment in the Saskatchewan River Delta to minimize dam‐induced issues.
Enhancing Metallocene Catalyst Activity: Utilizing Layered Double Hydroxide for Ethylene–Propylene Copolymerization
Authors: Mazhar Hassam , Shehzad Farrukh , Hong Sung‐Gil , Al‐Harthi Mamdouh A.
Published: October 2023

This study reports the heterogenization of metallocene catalysts on sodium dodecyl sulfate (DDS)‐modified layered double hydroxides (LDHs) for efficient ethylene–propylene (EP) slurry‐phase copolymerization. The LDH support offers considerable compositional tunability. NiFe LDHs with different anions () and metallic compositions are applied as support for the metallocene catalysts; these significantly influence the catalytic properties of the heterogenized catalyst system. The supported‐catalyst intercalating DDS− anion in the galleries of NiFe and ZnAl LDHs demonstrates a high catalytic activity. They produce EP copolymers with high molecular weights (Mw) and wide polydispersity, compared with the homogeneous Zr catalyst. Further, the supported catalyst complex containing anion produces EP with a tenfold high Mw and demonstrate subdued catalytic activity. The higher basicity of the support is associated with the enhanced activity and the wider polydispersity of the EP pertaining to the different interactions of the catalyst molecule with the support. Overall, Ni‐containing LDH favors a higher activity, whereas Fe‐containing LDH favors a higher Mw. Therefore, NiFe‐based LDH results in both higher activity and molecular weight. 13C and 27Al magnetic angle spinning solid‐state nuclear magnetic resonance confirm the formation of the supported catalyst complex.
Comparison between statistical and dynamical downscaling of rainfall over the Gwadar‐Ormara basin, Pakistan
Authors: Attique Raazia , Rientjes Tom , Booij Martijn
Published: October 2023

This paper evaluated and compared the performance of a statistical downscaling method and a dynamical downscaling method to simulate the spatial–temporal rainfall distribution. Outputs from RegCM4 Regional Climate Model (RCM) and the CanESM2 Atmosphere–Ocean General Circulation Model (AOGCM) were selected for the data scarce Gwadar‐Ormara basin, Pakistan. The evaluation was based on the climatological average and standard deviation for historic (1971–2000) and future (2041–2070) time periods under Representative Concentration Pathways (RCP) 4.5 and 8.5 scenarios. The performance evaluation showed that statistical downscaling is preferred to simulate and project rainfall patterns in the study area. Additionally, the Statistical DownScaling Model (SDSM) showed low R2 values in calibration and validation of the simulations with respect to observed data for the historic period. Overall, SDSM generated satisfactory results in simulating the monthly rainfall cycle of the entire basin. In this study, RegCM4 showed large rainfall errors and missed one rainfall season in the historic period. This study also explored whether the grid‐based rainfall time series of the Asian Precipitation—Highly Resolved Observational Daily Integration Towards Evaluation (APHRODITE) dataset could be used to enlarge and complement the sample of in situ observed rainfall time series. A spatial correlogram was used for observed and APHRODITE rainfall data to assess the consistency between the two data sources, which resulted in rejecting APHRODITE data. For the future time period (2041–2070) under RCPs 4.5 and 8.5 scenarios, rainfall projections did not show significant difference for both downscaling approaches. This may relate to the driving model (CanESM2 AOGCM) and not necessarily suggests poor performance of downscaling; either statistical or dynamical. Hence, the study recommends evaluating a multi‐model ensemble including other GCMs and RCMs for the same area of study.
Extracranial germ cell tumours: Mature and immature (1990–2015). First report by the South African Association of Paediatric Haematology Oncology (SAAPHO)
Authors: Hendricks Marc , Cois Annibale , Geel Jennifer , van Heerden Jaques , Naidu Gita , Plessis Jan du , van Zyl Anel , Bassingthwaighte Mairi , Omar Fareed , Büchner Ané , Rowe Biance , Thomas Karla , Uys Ronelle , Mahlachana Ngoakoana , Davidson Alan , Frazier L A. Lindsay , Donald Kirsten A. , Kruger M Mariana
Published: October 2023

Background and objectives

Outcomes of rare paediatric teratomas have not previously been reported nor treatment regimens standardised in low‐ and middle‐income settings. We sought to evaluate treatment outcomes of children and adolescents with histologically confirmed extracranial germ cell tumours, both mature teratomas (MT) and immature teratomas (IT) in preparation for the development of the South African national treatment guideline.

Methods

Retrospective data by folder review were collated from nine South African paediatric oncology units. Kaplan–Meier analysis with Cox regression was performed to determine 5‐year overall survival (OS) and prognostic factors.

Results

From January 1990 to December 2015, 60 patients were diagnosed with MTs; 14 males (median age 2 months; interquartile range [IQR]: 0–8.75 months) and 46 females (median age 9 months; IQR: 0–88.5 months). Forty patients were diagnosed with ITs; 10 males (median age less than 1 month; IQR: 0–1.75 months) and 30 females (median age 4.5 months; IQR: 1–162 months). There were high rates of upfront surgical resections in patients with MTs (58/60; 96.6%) and ITs (36/40; 90%), and similarly satisfactory rates of complete resection in patients with both MTs (55/60; 91.7%) and ITs (32/40; 80%). The 5‐year OS for the whole group was 85.4%, significantly influenced by stage: Stage I (96.9%), Stage II (100%), Stage III (38.9%) (p < .001 [MT]; p = .013 [IT]). The event‐free survival (EFS) ratio for the whole cohort was 78.7%.

Conclusions

Five‐year OS for those with low‐stage disease was excellent, but was poorer for patients with advanced disease. The implementation of a national treatment guideline will facilitate the standardising of surgical approaches, indications for chemotherapy and specifications for follow‐up to improve survival and to collect more robust late effects data.
Peripheral structural modification for devising push–pull strategy into 1,3,5‐triaryl‐2‐pyrazoline‐based compounds for nonlinear optical insights via density functional theory approach
Authors: Arshad Muhammad Nadeem , Khalid Muhammad , Hani Umme , Asiri Abdullah M.
Published: October 2023

The nonlinear optical (NLO) insights of triarylpyrazoline‐based (Z)‐2‐(2‐((7‐(4‐(5‐[2,4‐dimethylphenyl]‐1‐phenyl‐4,5‐dihydro‐1H‐pyrazol‐3‐yl)phenyl)‐4,4,9,9‐tetramethyl‐4,4a,9,10a‐tetrahydro‐s‐indaceno[1,2‐b:5,6‐b′]dithiophen‐2‐yl)methylene)‐3‐oxo‐2,3‐dihydro‐1H‐inden‐1‐yl)malononitrile (PR) and its derivatives P1–P7 were explored in this study. The compounds: PR and P1–P7 having donor–π–acceptor configurations and M06/6‐311G(d,p) functional was selected to inquire the dipole moment (μ), linear polarizability (α), first hyperpolarizability (β), and second hyperpolarizability (γ). The findings of perturbed Kohn–Sham relations were deciphered to derive charge density of the molecules. The optical analysis was performed in gaseous phase and their findings were observed in 544.2–697.1 nm range. Moreover, the natural bond orbitals, frontier molecular orbitals, density of state, and transition density matrices for the aforesaid compounds were also calculated at aforesaid level. Global reactivity parameters of PR and P1–P7 were analyzed by using highest occupied molecular orbital–lowest unoccupied molecular orbital energies. Overall, all above‐mentioned findings revealed significant optical nonlinear response in these pyrazoline‐based scaffold (PR and P1–P7). However, among all the compounds, P3 has shown the highest nonlinearity with maximum μtot, <α>, βtot, and γtot values at 19.4 D, 1.78 × 10−22, 2.57 × 10−27, and 3.13 × 10−32 a.u., respectively. Hence, the current computational study might prove to be fruitful for the exploration of proficient NLO materials for optoelectronic devices.
Salt and solvent effects on alkaline hydrolysis of N‐hydroxyphthalimide. Kinetic evidence for ion‐pair formation
Authors: Khan M. Niyaz
Published: October 2023

The effects of the concentrations of LiCl, NaCl, KCl, CsCl, Na2CO3 and BaCl2 on the rates of reactions of hydroxide ion with ionized N‐hydroxyphthalimide (NHP−) at 30°C and in H2O–MeCN solvents containing 10, 50, 60, 66, 70, 76 and 80% (v/v) MeCN reveal the formation of ion‐pair complexes between cations of the salts, which probably exist in solvent‐separated loose ion‐pair forms (Mn+ ⃛Xk−) and NHP−. An increase in MeCN content from 2 to 76% (v/v) causes an increase in the association constants (K) by factors of 40, 21 and 9 for LiCl, NaCl and KCl, respectively, while the respective increase in the rate constants (k′s1) for the collapse of the ion‐pair complexes to product is ca two‐fold. The values of k′s1 remain almost unchanged whereas the values of K increase 7·5‐fold with an increase in MeCN content from 2 to 70% (v/v) for CsCl. Ion‐pair complex formation was not detected in the presence of Me4NCl at 70% (v/v) MeCN. The observed pseudo‐first‐order rate constants are highly sensitive to the valence state of cations and almost insensitive to the valence state of the anions of the salts.
VirulentPred 2.0: An improved method for prediction of virulent proteins in bacterial pathogens
Authors: Sharma Arun , Garg Aarti , Ramana Jayashree , Gupta Dinesh
Published: October 2023

Virulence proteins in pathogens are essential for causing disease in a host. They enable the pathogen to invade, survive and multiply within the host, thus enhancing its potential to cause disease while also causing evasion of host defense mechanisms. Identifying these factors, especially potential vaccine candidates or drug targets, is critical for vaccine or drug development research. In this context, we present an improved version of VirulentPred 1.0 for rapidly identifying virulent proteins. The VirulentPred 2.0 is based on training machine learning models with experimentally validated virulent protein sequences. VirulentPred 2.0 achieved 84.71% accuracy with the validation dataset and 85.18% on an independent test dataset. The models are trained and evaluated with the latest sequence datasets of virulent proteins, which are three times greater in number than the proteins used in the earlier version of VirulentPred. Moreover, a significant improvement of 11% in the prediction accuracy over the earlier version is achieved with the best position‐specific scoring matrix (PSSM)‐based model for the latest test dataset. VirulentPred 2.0 is available as a user‐friendly web interface at https://bioinfo.icgeb.res.in/virulent2/ and a standalone application suitable for bulk predictions. With higher efficiency and availability as a standalone tool, VirulentPred 2.0 holds immense potential for high throughput yet efficient identification of virulent proteins in bacterial pathogens.
TetR and OmpR family regulators in natural product biosynthesis and resistance
Authors: Patil Rachit S. , Sharma Siddhant , Bhaskarwar Aditya V. , Nambiar Souparnika , Bhat Niharika A. , Koppolu Mani Kanta , Bhukya Hussain
Published: October 2023

This article provides a comprehensive review and sequence‐structure analysis of transcription regulator (TR) families, TetR and OmpR/PhoB, involved in specialized secondary metabolite (SSM) biosynthesis and resistance. Transcription regulation is a fundamental process, playing a crucial role in orchestrating gene expression to confer a survival advantage in response to frequent environmental stress conditions. This process, coupled with signal sensing, enables bacteria to respond to a diverse range of intra and extracellular signals. Thus, major bacterial signaling systems use a receptor domain to sense chemical stimuli along with an output domain responsible for transcription regulation through DNA‐binding. Sensory and output domains on a single polypeptide chain (one component system, OCS) allow response to stimuli by allostery, that is, DNA‐binding affinity modulation upon signal presence/absence. On the other hand, two component systems (TCSs) allow cross‐talk between the sensory and output domains as they are disjoint and transmit information by phosphorelay to mount a response. In both cases, however, TRs play a central role. Biosynthesis of SSMs, which includes antibiotics, is heavily regulated by TRs as it diverts the cell's resources towards the production of these expendable compounds, which also have clinical applications. These TRs have evolved to relay information across specific signals and target genes, thus providing a rich source of unique mechanisms to explore towards addressing the rapid escalation in antimicrobial resistance (AMR). Here, we focus on the TetR and OmpR family TRs, which belong to OCS and TCS, respectively. These TR families are well‐known examples of regulators in secondary metabolism and are ubiquitous across different bacteria, as they also participate in a myriad of cellular processes apart from SSM biosynthesis and resistance. As a result, these families exhibit higher sequence divergence, which is also evident from our bioinformatic analysis of 158 389 and 77 437 sequences from TetR and OmpR family TRs, respectively. The analysis of both sequence and structure allowed us to identify novel motifs in addition to the known motifs responsible for TR function and its structural integrity. Understanding the diverse mechanisms employed by these TRs is essential for unraveling the biosynthesis of SSMs. This can also help exploit their regulatory role in biosynthesis for significant pharmaceutical, agricultural, and industrial applications.
Feeding cessation after feeding on 20‐hydroxyecdysone in the Formosan subterranean termite
Authors: Lee Sang‐Bin , Carnohan Lucas , Gazdick Kaitlin , Chouvenc Thomas , Su Nan‐Yao
Published: October 2023

BACKGROUND

To control subterranean termite pests, chitin synthesis inhibitor (CSI) baits have been widely applied. Despite CSI baits having low impacts on the environment, they require a lengthy time period to eliminate colonies. 20‐hydroxyecdysone (20E) was proposed to speed up the baiting process as it showed faster mortality than CSI baits. However, the efficacy of 20E has previously not been tested at the colony level prior to applying in the field.

RESULTS

We compared the effect of 20E, 20E + noviflumuron, noviflumuron and untreated control using colonies of Coptotermes formosanus. Our result revealed that both 20E and 20E + noviflumuron did not accelerate colony elimination and termite activity remained relatively stable during the observation periods. To determine the limited effects of 20E, we further investigated feeding duration and consumption amount of 20E with different concentrations (control, 100 and 1000 ppm) for 10 days. Termites ceased feeding after 1 day in 100 and 1000 ppm treatment and 100% mortality was observed within 10 days in 1000 ppm 20E, while mortality in the 100 ppm 20E treated group was much lower than that in the 1000 ppm group. Furthermore, no termites molted in the control and termites died from hyperecdysonism in 1000 ppm 20E treatment, whereas about 20% of termites molted in 100 ppm 20E.

CONCLUSION

This study demonstrated that 20E may not be suitable as a sole active ingredient to accelerate elimination of a subterranean termite colony, while CSI baits and lower concentrations of 20E may reduce the lengthy time period in colony elimination. © 2023 Society of Chemical Industry.
Determination and gas‐phase stability evaluation of metal complexes by nanoelectrospray ionization and collision‐induced dissociation tandem mass spectrometry
Authors: Li Xi , Sawada Keisuke , Shioji Hirotaka
Published: October 2023

Rationale

The structures of metal complexes determine their stable functioning in product performance. Electrospray ionization mass spectrometry (ESI‐MS) is used in studying metal complexes despite exhibiting limitations in analyzing labile complexes. Therefore, identifying a method for detecting unstable complexes and evaluating their stabilities is necessary, providing a theoretical basis for material selection and performance evaluation.

Methods

The standard complexes Zn(BTZ)2, Fe(acac)3, and Sn(Oct)2 were analyzed using nanoESI quadrupole orbitrap MS (nanoESI‐MS) and compared with ESI‐MS for two temperature modes. The three complexes and alkylamine–Ag+ complexes were analyzed using nanoESI and collision‐induced dissociation MS/MS (CID‐MS/MS). Breakdown plots of the survival yield against collision energies expressed in terms of the center‐of‐mass were constructed according to the obtained product ion spectra. Quantum chemical calculations based on density functional theory were performed to calculate the binding energies between the alkylamines and Ag+.

Results

The three standard complexes were detected in the native structures using nanoESI‐MS, confirming the advantage of nanoESI over ESI for detecting unstable complexes. The gas‐phase stabilities of the amine–Ag+ complexes, estimated using the breakdown plots constructed by plotting the data obtained via nanoESI and CID‐MS/MS, were consistent with the established theories, previous studies, and binding energies calculated using computational methods.

Conclusions

NanoESI‐MS is suitable for detecting labile complexes and enables the structural analyses of unknown complex additives. A novel approach based on nanoESI and CID‐MS/MS was developed to determine the gas‐phase stabilities of complexes, enabling their quantification and comparison and providing a technical basis for product improvement, which is essential in developing industrial materials.
Probing the Phase Transition to a Coherent 2D Kondo Lattice
Authors: Ayani Cosme G. , Pisarra Michele , Ibarburu Iván M. , Garnica Manuela , Miranda Rodolfo , Calleja Fabián , Martín Fernando , Vázquez de Parga Amadeo L.
Published: October 2023

Kondo lattices are systems with unusual electronic properties that stem from strong electron correlation, typically studied in intermetallic 3D compounds containing lanthanides or actinides. Lowering the dimensionality of the system enhances the role of electron correlations providing a new tuning knob for the search of novel properties in strongly correlated quantum matter. The realization of a 2D Kondo lattice by stacking a single‐layer Mott insulator on a metallic surface is reported. The temperature of the system is steadily lowered and by using high‐resolution scanning tunneling spectroscopy, the phase transition leading to the Kondo lattice is followed. Above 27 K the interaction between the Mott insulator and the metal is negligible and both keep their original electronic properties intact. Below 27 K the Kondo screening of the localized electrons in the Mott insulator begins and below 11 K the formation of a coherent quantum electronic state extended to the entire sample, i.e., the Kondo lattice, takes place. By means of density functional theory, the electronic properties of the system and its evolution with temperature are explained. The findings contribute to the exploration of unconventional states in 2D correlated materials.
Mechanical–electrical‐grid model for the doubly fed induction generator wind turbine system considering oscillation frequency coupling characteristics
Authors: Wang Zheng , Lu Yimin
Published: October 2023

With the evolution of renewable energies, many doubly fed induction generators (DFIGs) are being connected to the power grid, whose operation and grid‐connection stability have a major impact on the power grid. Currently, most studies focus on either modeling the mechanical–electrical section or the electrical‐grid section, and discussions have been limited to shaft oscillation or frequency coupling problems. In this study, a mechanical–electrical‐grid model of a DFIG was established to examine the impacts of wind speed and system control parameters on electrical damping and grid‐connection stability. The accuracy of the proposed model and validity of the analyses were verified using simulations. The following were observed: (1) In the case of changing wind speeds, the wind speed and the applied control model determine the shaft oscillation of DFIG, whereas the grid‐connected impedance on the rotor side is dependent on the wind speed. (2) At a constant wind speed, changes in control parameters under different control modes affect the dynamic characteristics of the drive train differently, whereas the grid‐connected impedance on the rotor side is primarily determined by the proportional gain of the inner/outer loop of the control system. The conclusions drawn from this study can further improve the safe and stable operation of DFIG wind power generation systems as well as their connection to the power grid.
Protecting the resource: an assessment of mitigation methods used to protect large trees from African elephant impact in a savanna system
Authors: Cook Robin M. , F. Witkowski Edward T. , Henley Michelle D.
Published: October 2023

African elephants Loxodonta africana can alter the structural components of savanna ecosystems, often through the reduction of the large tree (≥ 5 m height) cover component. Elephant impact can be amplified in small, protected areas, or areas where water is readily available to elephants. One management option is to protect large trees directly using applied mitigation methods to limit elephant impact. In this paper, we assessed and compared the effectiveness and logistical requirements of four mitigation methods that have been applied to protect large trees from elephant impact in South Africa's Greater Kruger National Park – namely African honeybees Apis mellifera scutellata in beehives; creosote oil in glass jars, concrete pyramids arranged in circles around trees, as well as wire‐netting the trees' main stems. For each method, elephant impact levels and tree mortality rates were measured over a 2–5‐year period depending on the method in use. Sample sizes ranged from 43 to 59 trees per mitigation method, with a comparable control, which was a tree of the same species and morphological dimensions but lacking any mitigation application. Beehives were the most effective method at reducing tree loss, significantly reducing tree mortality from 34% (6.8%/year) in control trees to only 10% (2% year‐1) over the five‐year experimental period. However, beehives were the most expensive method to apply to a tree, although this cost can be compensated through honey sales. Concrete pyramids reduced tree loss when the combined pyramid radius was > 1.5 m in length, whilst wire‐netting was effective against bark‐stripping by elephants but was still vulnerable to heavier forms of impact such as uprooting and stem snapping. Creosote jars did not prevent elephants from impacting treated trees. Our results provide managers with a toolkit for protecting large trees against elephant impact, commenting on both the efficacy and the logistical constraints for each method.
Water–energy–food nexus in Kenya: A review of policy interventions
Authors: Kanda Edwin Kimutai , Lusweti Elizabeth , Odhiambo Kevin O.
Published: October 2023

The water–energy–food (WEF) nexus approach is important in promoting sustainable management of resources, alleviating poverty and achieving sustainable development goals (SDGs). Given the importance of the WEF nexus, it is currently being promoted and developed in most countries via policy interventions as a response to climate change‐related problems and other nexus challenges. In the past, Kenya faced numerous challenges in achieving SDGs concerning food, water, and energy security. To address this, cross‐sectorial policy interventions, legal instruments, and institutional frameworks have been developed. Therefore, this review evaluates the major policies, interventions, and strategies related to WEF, their interconnection, and their relevance to SDG targets. The review also assesses the efficacy of the policies and highlights gaps and potential for policy change. The key strategic interventions considered include Kenya Vision 2030, agriculture, energy, and water policies. From the review, there have been some successful policy measures. However, the intricate interconnections between the water, energy, and food sectors necessitate a more integrated strategy for achieving sustainability. The water policy is central to the achievement of SDGs for WEF security. Therefore, there is a need for the implementation of a holistic approach between the WEF agencies and stakeholders to address the policy interventions required for sustainable development. Water policies should be aligned with other interlinked policies on food, energy, and the environment.
Kalkaneoplastie mit Radiofrequenzzementierung nach Ballonaufrichtung
Authors: Rathjen J. , Völlmecke M. , Bieler D. , Franke A. , Kollig E.
Published: October 2023

Als operatives Standardverfahren von komplexen Kalkaneusfrakturen gilt die offene Reposition und interne winkelstabile Plattenosteosynthese über einen lateralen Zugang. In jüngerer Zeit wurden auch Optionen für minimalinvasive und perkutane Verfahrensstrategien vorgestellt [7, 4]. Als mögliche Verfahrensalternative für eine gedeckte, operative Versorgung von Fersenbeinbrüchen wird in diesem Zusammenhang die Kalkaneoplastie diskutiert und angewendet [5]. In der hier vorgestellten Fallserie von 5 versorgten, komplexen Kalkaneusfrakturen wurde ein Ballonkatheter zur perkutanen Reposition verwendet, um das Alignment des Kalkaneus wiederherzustellen.

Anschließend erfolgten das Einbringen von PMMA-Zement in Radiofrequenzanwendung und die Osteosynthese mittels perkutanen, kanülierten Schrauben. Diese Technik erlaubt nach Vicenti eine stabile Reposition und Retention mit früher Teilbelastung bei insgesamt geringer Komplikationsrate [17].
Detrimental impact of a heatwave on male reproductive behaviour and fertility
Authors: Grandela Afonso , Antunes Marta A. , Santos Marta A. , Matos Margarida , Rodrigues Leonor R. , Simões Pedro
Published: October 2023

Understanding how heatwaves impact on different aspects of mating behaviour and fertility is getting increasingly important. In this context, laboratory fertility and mating experiments involving manipulation and exposure of insects to different thermal conditions are common procedures. To conduct such experiments practical methods such as dyes are needed for an easy, non-invasive discrimination of individuals. We report here a study measuring the effect of an extended heat stress applied to males on several parameters of mating behaviour and fertility of laboratory populations of Drosophila subobscura derived from two distinct European locations. We found highly detrimental effects of heatwave on mating behaviour—with longer (courtship and copulation) latencies and lower mating occurrence but no changes in mating duration—and fertility, with reduced fecundity and reproductive success. Furthermore, we also tested the efficacy of food dye as a marker for individual discrimination and mating occurrence. While food dye did not allow to infer the occurrence of a mating based on a transfer of coloration from male to female, it did not affect mating and fertility, attesting its utility has a method for discriminating individuals within mating experiments in the context of thermal studies. Importantly, despite the fact that the heatwave was only applied in males, we observed an impact on behaviour of females that mated with stressed males, by often refusing their nuptial feeding. This opens possibilities for further integrated research on the changes of female and male mating behaviour and fertility under different thermal scenarios.
Priority regions for eliminating open defecation in Africa: implications for antimicrobial resistance
Authors: Fagunwa Omololu Ebenezer , Mthiyane Thobile , Fagunwa Ayokunle , Olayemi Kassim Idowu , Alozie Alaoma , Onyeaka Helen , Akinsemolu Adenike , Ojo Adegbola
Published: October 2023

Sanitation, which offers safe and effective methods for waste disposal, is important for development. However, in Africa and other developing regions, the prevalent practice of open defecation (OD) impedes attaining the sustainable development goals (SDGs). This research delves into the analysis of OD in Africa and proposes a three-tier priority system, comprising critical, high, and medium areas, through which developmental endeavours can be targeted. To achieve this, the study utilizes data from demographic and health surveys (DHS) and the World Bank. The rates of OD at country and sub-country/region levels were calculated to define the priority system, and regression analyses were used to determine predictors of OD practice. The findings are that Nigeria, Ethiopia, Niger, the Democratic Republic of Congo, Burkina Faso, and Chad have a high number of people struggling with open defecation. In addition, disparities in access to proper sanitation facilities were identified among impoverished individuals and those residing in rural areas. After adjusting for education and residence, the poorest are 43 times (95% confidence interval 42.443–45.290) more likely to practice open defecation in comparison with the wealthiest. Consequently, wealth index is a pivotal factor in eradicating open toileting. To address this pressing issue in Africa, it is imperative to prioritize evidence-based targeted interventions that concentrate on regions and communities urgently needing improved sanitation infrastructure and programmes. Special attention should be paid to West Africa since many of its communities are in the critical category. Poverty and inequality must be addressed and investments in sanitation infrastructure, behavioural change promotion, and support multistakeholder collaborations should be encouraged. To evaluate OD interventions and monitor health impact, variables such as antimicrobial resistance (AMR) should be included in important health surveys (e.g. DHS). This study is the largest meta-data analyses of OD in Africa detailing drivers and communities that should be prioritised on sanitation interventions.