Effect of endogenous hormones, antisperm antibody and oxidative stress on semen quality of crossbred bulls.

The present study was designed to evaluate the effect of factors like hormones, antisperm antibody (ASA), and oxidative stress and its relation with semen quality in crossbred bulls. Ejaculates from two bulls were categorized into good (n = 12) and poor (n = 12) based on initial progressive motility, that is, ≥70% and ≤50%, respectively. The level of hormones like Testosterone (p < 0.05) and PGE2 (p < 0.01) was significantly higher in good-quality ejaculates compared to poor-quality ejaculates; however, estradiol (p < 0.05), progesterone, oxidative stress, and ASAs were significantly higher (p < 0.01) in poor-quality ejaculates compared to good-quality ejaculates. Therefore, it could be concluded that oxidative stress and hormonal imbalance might have resulted in high number of dead and defective spermatozoa which was ultimately responsible for poor quality semen ejaculates.

Correlation between dissolved oxygen level, antioxidants and oxidants in semen diluted with partially deoxygenated extender at various stages of cryopreservation.

BACKGROUND: Dissolved oxygen (DO) in semen dilutor may lead to the production of reactive oxygen species (ROS) and buffalo sperm may become more prone to deleterious effects of ROS due to the presence of high amounts of polyunsaturated fatty acids (PUFAs) in their membranes. OBJECTIVE: To study the correlation between dissolved oxygen level, antioxidants and oxidants in semen diluted with partially deoxygenated extender at various stages of cryopreservation. MATERIALS AND METHODS: Each semen sample was split into two aliquots viz., Aliquot I [diluted with Extender I (control: without deoxygenation)] and Aliquot II [diluted with Extender II: partially deoxygenated by liquid nitrogen (LN) flushing], which were diluted, filled in straws, cryopreserved and evaluated post-thaw. RESULTS: The DO levels (P < 0.05) decreased significantly after LN flushing of the extender and they increased significantly (P < 0.05) in post-thaw semen. The progressive motility, viability, hypo-osmotic swelling response, acrosomal integrity, glutathione peroxidase (GPx), total antioxidant capacity (TAC) and superoxide dismutase (SOD) decreased significantly (P < 0.05) in both control and treated semen after thawing. SOD and TAC were positively correlated in semen treated with normal extender at the pre-freeze stage; however, in semen treated with partially deoxygenated extender, no correlation was found between SOD and TAC at the pre-freeze stage. ROS and total TAC were negatively correlated in semen treated with partially deoxygenated extender at the pre-freeze stage; however, no correlation was found between ROS and TAC in control semen. CONCLUSION: The partial deoxygenation of extender affects the correlation between sperm quality parameters, antioxidants, and oxidants during different stages of semen cryopreservation. doi.org/10.54680/fr22310110712.

Cryoprotection of humanin-like peptides in seminal plasma for ejaculated spermatozoa of crossbred bulls.

BACKGROUND: Cryopreservation process negatively affects spermatozoa functions. Humanin, a small polypeptide encoded in the mitochondrial genome, is well known for its role in cell survival. OBJECTIVE: To quantify the endogenous levels of humanin in seminal plasma of crossbred Frieswal bulls and to study its role in cryoprotection. The presence of humanin in bull spermatozoa was also investigated. MATERIALS AND METHODS: A total of 40 semen samples were separated into two groups based on the initial progressive motility (IPM): Good (IPM >70%) and Poor (IPM <50%) groups; and/or based on the post-thaw motility (PTM): Freezable (PTM>50%) and Non-freezable (PTM < 50%) groups. Humanin concentration in seminal plasma (SP-HN) was quantified using ELISA. RESULTS: SP-HN concentration ranged from undetectable to 67.6 pg/mL with a median level of 35.2 pg/mL. SP-HN level was significantly higher in the good quality semen group than in the poor quality semen group (p<0.001), and also significantly higher in the freezable group than in the non-freezable group (p<0.001). SP-HN level was positively correlated with initial progressive motility, post-thaw semen motility, viability, acrosome intactness and plasma membrane integrity, but negatively correlated the level of reactive oxygen species and malondialdehyde content. Immunochemical localization showed the presence of humanin in the proximal region of the middle piece of spermatozoa. CONCLUSION: Endogenous humanin level had significant correlation with semen quality and might protect sperm cells against freeze-induced oxidative stress. doi.org/10.54680/fr22510110712.

Cryoprotectant with a mitochondrial derived peptide, humanin, improves post-thaw quality of buffalo spermatozoa.

BACKGROUND: Semen cryopreservation results in deleterious effects on spermatozoa, including lipid peroxidation and a reduction in the total antioxidant components of seminal plasma. The ultimate outcome of these changes is a reduction in post-thaw semen quality. A mitochondrial derived peptide, humanin, a potent cytoprotective and antioxidant agent was used in the present study. OBJECTIVE: To evaluate the efficacy of a mitochondrial-derived peptide, humanin to improve the post-thaw quality of buffalo spermatozoa. MATERIALS AND METHODS: A total of 18 ejaculates from three Murrah buffalo bulls (n=6 each) were collected. Each ejaculate was divided into four aliquots. The first aliquot was diluted with standard EYTG dilutor (Group I, control), whereas the other three aliquots were diluted with EYTG supplemented with 2 µM (Group II), 5 µM (Group III) and 10 µM humanin (Group IV), respectively. Semen was evaluated for physico-morphological and functional attributes such as progressive motility, viability, abnormality, acrosome integrity, plasmamembrane integrity of fresh samples, pre-freeze and post-thaw stages. Oxidative stress parameters [lipid peroxidation (LPO) and total antioxidant capacity (TAC)] were also measured at the pre-freeze and post-thaw stages. RESULTS: Humanin supplementation resulted in significantly higher (p < 0.05) post-thaw motility in all treatment groups and, higher (p < 0.05) viability in Groups III and IV in comparison to the control at the post-thaw stage. Spermatozoa with intact acrosome and plasma membrane were higher (p < 0.05) in Groups III and IV as compared to Groups I and II. The LPO levels at the post-thaw stage were found to be lower (p < 0.05) in all treatment groups versus the control group, whereas, higher (p≤0.05) TAC values were recorded in Groups III and IV in comparison to the control and Group II. CONCLUSION: Humanin supplementation in the extender improved the freezabilty of buffalo spermatozoa.

Effect of Cryopreservation on Semen Quality Parameters in Relation to Lipid Peroxidation and Antioxidant Profile in Indian Buffalo.

BACKGROUND: Lipid peroxidation (LPO) due to oxidative stress leads to structural and functional changes in spermatozoa. OBJECTIVE: To evaluate any association of various seminal characteristics at the pre- and post-cryopreservation stages with LPO and total antioxidant capacity (TAC) in Murrah buffalo semen samples. MATERIALS AND METHODS: Sixty-five ejaculates from seven bulls were processed for cryopreservation in liquid nitrogen. RESULTS: Only 31 (47.7%) samples were found satisfactory for inclusion in the further artificial insemination. A strong negative correlation was observed between LPO and individual progressive motility, TAC, viability, plasma membrane integrity as well as acrosome integrity of fresh spermatozoa. At the post-thaw stage, post-thaw motility, viability, plasma membrane integrity and acrosome integrity had strong positive correlation with TAC. CONCLUSION: The effort to minimize LPO and enhance TAC shall play a pivotal role in improving buffalo semen quality upon cryopreservation.

Effect of Mito-TEMPO Incorporated Semen Extender on Physico-morphological Attributes and Functional Membrane Integrity of Frozen Thawed Buffalo Spermatozoa.

BACKGROUND: Sperm mitochondria are the major site of reactive oxygen species (ROS) production and excess production during freezing-thawing process inflicts oxidative damages to spermatozoa. Buffalo spermatozoa are more prone to oxidative damage due to inherently more polyunsaturated fatty acids and low cholesterol to phospholipids ratio in the plasma membrane. A mitochondrial targeted antioxidant, Mito-TEMPO was used in this study. OBJECTIVE: To study the effect of Mito-TEMPO incorporated semen extender on the post-thaw semen quality in buffalo. MATERIALS AND METHODS: A total of 18 ejaculates from three murrah buffalo bulls with ≥70% individual progressive motility were utilized for the study. Each semen sample was equally divided and extended with five groups: Group I (Control, without Mito-TEMPO addition); Group II (10 µM Mito-TEMPO); Group III (50 µM Mito-TEMPO); Group IV (100 µM Mito-TEMPO); Group V (500 µM Mito-TEMPO) to have 80×106 progressive motile sperm/mL of extender, filled and sealed in French mini straws (0.25 mL) and frozen following equilibration. The effect of Mito-TEMPO was assessed at fresh/post-dilution and post-thaw stages by evaluating physico-morphological attributes and functional membrane integrity such as hypo-osmotic swelling test (HOST). RESULTS: Initial progressive motility, viability, acrosomal integrity and HOS response was significantly (p<0.05) improved and sperm abnormality was significantly (p<0.05) reduced in extended semen with Mito-TEMPO (50 µM) compared to control at post-thaw stage, although improvement was also observed at 10 and 100 µM in post-thaw samples. CONCLUSION: Mito-TEMPO incorporated semen extender at 50 µM concentration, could be part of a rationale for improving post-thaw semen quality in buffalo.

Cosmic ray flux and lockdown due to COVID-19 in Kolkata - Any correlation?

Cosmic ray muon flux is measured by the coincidence technique using plastic scintillation detectors in the High Energy Physics Detector Laboratory at Bose Institute, Kolkata. Due to the COVID-19 outbreak and nationwide complete lockdown, the laboratory was closed from the end of March 2020 till the end of May 2020. After lockdown, although the city is not in its normal state, we still were able to take data on some days. The lockdown imposed a strict restriction on the transport service other than the emergency ones and also most of the industries were shut down in and around the city. This lockdown has significant effect on the atmospheric conditions in terms of change in the concentration of air pollutants. We have measured the cosmic ray flux before and after the lockdown to observe the apparent change if any, due to change in the atmospheric conditions. In this article, we report the measured cosmic ray flux at Kolkata (22.58 ∘ N 88.42 ∘ E and 11 m above the Sea Level) along with the major air pollutants present in the atmosphere before and after the lockdown.

Adrenal Myelolipoma Mimics Ectopic Adrenal or Renal Tissue: An Incidental Finding During Cadaveric Dissection.

CONTEXT: On naked eye examination adrenal myelolipoma (AML) tissue appears to be an ectopic adrenal or renal tissue, based on the similarity to their external texture. This necessitates a histo-pathological study for confirming the origin of the tissue. OBJECTIVE: To establish the origin and histological features of the incidental AML tissue found during cadaveric dissection and review the literature for similar findings with clinical picture and treatment description. SUBJECTS AND METHODS: Unilateral adrenal gland obtained from cadaveric dissection was subjected to histological study by H & E staining of the slides prepared. The literature review was done from articles published in PubMed indexed journals. CASE REPORT: A case of an incidental finding of AML during cadaveric dissection is presented which on naked eye examination was appearing to be an ectopic adrenal or renal tissue, based on the similarity to their external texture. On histological examination, a thin rim of adrenocortical tissue, surrounding the mature adipose tissue, and attenuated by islets of myeloid, erythroid and megakaryocytic cell lines in varying proportions, resembling the mature bone marrow morphology, was observed. The literature review on PubMed explains similar incidental post-mortem autopsy findings due to the asymptomatic nature of the tumor. The incidence of AML varied between 0.08% and 0.2% in the last decade of the 20th century, which increased up to 10 - 15% of incidental adrenal masses due to the widespread use of non-invasive imaging modalities leading to an increase in the diagnosis of the pathology. CONCLUSIONS: Before considering the ectopic incidence of tissue during cadaveric dissection, a histo-pathological examination is mandatory for confirmation. Adreno-myelolipoma is an asymptomatic post-mortem finding in 10-15% of cases of adrenal tissue which mimics ectopic adrenal gland or renal tissue due to its external texture.

Surface Activities of a Lipid Analogue Room-Temperature Ionic Liquid and Its Effects on Phospholipid Membrane.

There are great efforts of synthesizing imidazolium-based ionic liquids (ILs) for developing new antibiotics as these molecules have shown strong antibacterial activities. Compared to a single-hydrocarbon-chained IL, the lipid analogues (LAs) with two chains are more effective. In the present study, the LA molecule MeIm(COOH)Me(Oleylamine)Iodide has been synthesized and its surface activities along with the effectiveness in restructuring of a model cellular membrane have been quantified. The molecule is found to be highly surface active as estimated from the area-pressure isotherm of a monolayer of the molecules formed at the air-water interface. The X-ray reflectivity (XRR) studies of a monolayer dip-coated on a hydrophilic substrate have shown the structural properties of the layer which resembles to those of unsaturated phospholipids. The LA molecules are observed to fluidize a phospholipid bilayer formed by the saturated lipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). At a lower surface pressure, the lipid monolayer of DPPC has exhibited a thickening effect at a low concentration of added LA and a thinning effect at higher concentration. However, at a high surface pressure of the monolayer, the thickness is found to decrease monotonically. The in-plane pressure-dependent interaction of LA molecules with model cellular membrane and the corresponding perturbation in the structure and physical properties of the membrane may be linked to the strong lysing effect of these types of molecules.

Evolution of structural and magnetic properties of FePtCu alloy films on annealing of FePt/Cu multilayers.

Thin films of ternary (FePt)100-xCux alloys were obtained by annealing of FePt (100 Å)/Cu (d Å) multilayers with d = 50 and 100 Å deposited by sputtering at room temperature on Si substrates. The evolution of structural and magnetic properties of these multilayers induced by isochronal and isothermal annealing in a vacuum has been studied using depth dependent characterization techniques. Isochronal annealing for 0.5 h at different temperatures (300 to 600 °C) showed very low interdiffusion at the interfaces with no signature of alloy phase formation. However, isothermal annealing of multilayers at 600 °C for longer times (1.5-6.5 h) showed significantly large interdiffusion accompanied by the formation of polycrystalline ternary alloy and iron silicide phases. The iron silicide formed at the substrate-film interface assists the growth of the L10 ordered ternary alloy phase, which showed different stoichiometry for different multilayers. The L10 phase formed with higher Cu content showed drastically different magnetic properties with a reduction in saturation magnetization and an increase in coercivity (∼6 kOe) at room temperature. The iron silicide formed on high temperature annealing showed ferromagnetic nature with a magnetization of ∼140 emu cm-3 at room temperature.

Exploring the role of E.coli derived enzyme, Oxyrase, as an oxygen scavenger to improve the cryotolerance of spermatozoa of Sahiwal bull.

The current study intended to optimize the concentration of Oxyrase in the semen dilutor and to evaluate its effect on freezability of spermatozoa of Sahiwal bulls. Supplementation of Oxyrase at 0.125 IU/mL concentration significantly reduced dissolved oxygen (DO) in the dilutor to 4 ppm in 16-18 min at 35 °C. For supplementation studies, a total of 24 ejaculates were categorized into poor and good ejaculates categories (n = 12 each) based on their initial progressive motility. Each ejaculate was further divided into two aliquotes. The first aliquote was diluted with tris-egg yolk extender without Oxyrase (control group) whereas, in the treatment group, Oxyrase was supplemented at the concentration of 0.125 IU/mL of extender. The parameters evaluated include cholesterol and plasma membrane phospholipids (PMP) at fresh, while IPM, acrosomal and plasma membrane integrity, cholesterol, PMP and oxidative stress parameters like lipid peroxidation (LPO), total antioxidant capacity (TAC) and reactive oxygen species (ROS) were evaluated at pre-freeze and post-thaw stages. The IPM and acrosomal intactness were higher (p < 0.05) in treatment group at post-thaw stage in good ejaculates. Oxyrase supplementation resulted in lower (p < 0.05) cholesterol leakage in both categories and lower (p < 0.05) LPO in good ejaculates at post-thaw stage. No statistical difference in ROS was observed between control and treatment groups at all stages whereas, level of TAC was higher (p < 0.05) in the treatment group compared to control group at post-thaw stage of both categories. Therefore, Oxyrase as an oxygen scavenging agent could preserve the post-thaw quality of Sahiwal bull spermatozoa.

EGF, GDNF, and IGF-1 influence the proliferation and stemness of ovine spermatogonial stem cells in vitro.

PURPOSE: The objective of the present study was to purify sheep spermatogonial stem cells (SSCs) from testicular isolate using combined enrichment methods and to study the effect of growth factors on SSC stemness during culture. METHODS: The testicular cells from prepubertal male sheep were isolated, and SSCs were purified using Ficoll gradients (10 and 12%) followed by differential plating (laminin with BSA). SSCs were cultured with StemPro®-34 SFM, additives, and FBS for 7 days. The various doses (ng/ml) of growth factors, EGF at 10, 15, and 20, GDNF at 40, 70, and 100 and IGF-1 at 50, 100, and 150 were tested for the proliferation and stemness of SSCs in vitro. The stemness in cultured cells was assessed using SSC markers PLZF, ITGA6, and GFRα1. RESULTS: Ficoll density gradient separation significantly (p < 0.05) increased the percentage of SSCs in 12% fraction (35.1 ± 3.8 vs 11.2 ± 3.7). Subsequently, purification using laminin with BSA plating further enriched SSCs to 61.7 ± 4.7%. GDNF at 40 ng/ml, EGF at 15 and 20 ng/ml and IGF1 at 100 and 150 ng/ml significantly (p < 0.05) improved proliferation and stemness of SSCs up to 7 days in culture. GDNF at 40 ng/ml outperformed other growth factors tested and could maintain the ovine SSCs proliferation and stemness for 36 days. CONCLUSIONS: The combined enrichment method employing density gradient centrifugation and laminin with BSA plating improves the purification efficiency of ovine SSCs. GDNF at 40 ng/ml is essential for optimal proliferation and sustenance of stemness of ovine SSCs in vitro.

Incubation with Cholesterol-loaded Cyclodextrin and Subsequent Dilution in Partially Deoxygenated Extender Improves the Freezability of Cross-bred Bull Sperm.

BACKGROUND: The cryopreservation process induces osmotic stress, membrane changes and production of reactive oxygen species resulting in damage to the spermatozoa. Together, the presence of oxygen in the extender aggravates the oxidative stress that further reduces the cryosurvival rate of sperm cells. OBJECTIVE: To study the combined effect of cholesterol loaded cyclodextrin (CLC) and partial deoxygenation on post-thaw semen quality in crossbred bulls. MATERIALS AND METHODS: A total of 18 ejaculates from three crossbred bulls with >3+ mass motility and >70% individual progressive motility were utilized for the study. Each semen sample was divided into four groups: Group I (containing extender without partial deoxygenation or CLC addition); Group II (extender containing 3 mg CLC/120X106 spermatozoa); Group III (extender containing 3 mg CLC/120X106 spermatozoa and 4 ppm dissolved oxygen (DO) level); Group IV (extender containing 3 mg CLC/120X106 spermatozoa and 6 ppm DO level). The samples in each group were finally extended to have 80×106 progressive motile sperm/mL of extender, filled and sealed in French mini straws (0.25 mL) and frozen following equilibration. The effect of CLC addition and partial deoxygenation was assessed at fresh (post-dilution), pre-freeze and post-thaw stages by evaluating various variables [sperm motility, viability, hypo-osmotic swelling (HOS) response, acrosomal integrity, capacitation status and mitochondrial membrane potential (MMP)]. RESULTS: The sperm population was significantly more positive for motility, viability, HOS response, acrosome intactness, high MMP and had less capacitation-like changes in groups supplemented with CLC and partially deoxygenation. However, the positive effect was most pronounced in the group that had extender with CLC+4 ppm DO. CONCLUSION: Partial deoxygenation of extender, and CLC addition in combination, could be part of a rationale for improving post-thaw semen quality in cross-bred bulls.

Detection of Atrial Fibrillation from Single Lead ECG Signal Using Multirate Cosine Filter Bank and Deep Neural Network.

Atrial fibrillation (AF) is a cardiac arrhythmia which is characterized based on the irregsular beating of atria, resulting in, the abnormal atrial patterns that are observed in the electrocardiogram (ECG) signal. The early detection of this pathology is very helpful for minimizing the chances of stroke, other heart-related disorders, and coronary artery diseases. This paper proposes a novel method for the detection of AF pathology based on the analysis of the ECG signal. The method adopts a multi-rate cosine filter bank architecture for the evaluation of coefficients from the ECG signal at different subbands, in turn, the Fractional norm (FN) feature is evaluated from the extracted coefficients at each subband. Then, the AF detection is carried out using a deep learning approach known as the Hierarchical Extreme Learning Machine (H-ELM) from the FN features. The proposed method is evaluated by considering normal and AF pathological ECG signals from public databases. The experimental results reveal that the proposed multi-rate cosine filter bank based on FN features is effective for the detection of AF pathology with an accuracy, sensitivity and specificity values of 99.40%, 98.77%, and 100%, respectively. The performance of the proposed diagnostic features of the ECG signal is compared with other existing features for the detection of AF. The low-frequency subband FN features found to be more significant with a difference of the mean values as 0.69 between normal and AF classes.

Anatomy of nervous system and emergence of neuroscience: A chronological journey across centuries.

Scholars began exploring anatomy of nervous system from ancient times; however, considerable progress could only be made during the European Renaissance from the 14th century onwards. The present study aimed to document significant discoveries in this context in chronological order to establish the cascading pattern of advancement in knowledge. The findings of Leonardo da Vinci (15th century), Vesalius (16th century) and their contemporaries, which were based on macroscopic dissection, helped to break the shackles of misconceptions in hypotheses prevalent from the time of Galen. However, very little headway could be achieved beyond superficial descriptions. Willis (17th century), through his experimental studies, provided the much-needed impetus and his discoveries put the study of brain and nervous system on their modern footing. In the following years, prominent researchers through their observations based on the use of microscopy and advanced histological techniques (prevalent after invention of microtome) contributed towards significant discoveries related to the morphological details of different components of nervous system. Such scientific activities culminated in remarkable advancements by the middle of 19th century. The advent of Golgi's staining technique and subsequent histological exploits of Cajal (late 19th century) established the neuron theory, which is central to comprehending the functioning of nervous system. Availability of Golgi's staining technique remarkably contributed in detailing the anatomical structure of nervous system at microscopic level. Access to structural details pertaining to living anatomy (late 20th century) and focus on findings at the molecular level by turn of 21st century have firmly established neuroscience as a sovereign academic discipline.

Ossification around intercavernous sinus: An osteological finding that can complicate trans - sphenoidal surgery.

The aim of the study was to document an anatomical variation around the sella turcica which was unique and lacked any reference in the literature. A low lying osseous bar connecting the right middle clinoid process to the midpoint of the right lateral border of the dorsum sella was observed in a human skull specimen. The osseous bar was forming a foramen close to the floor of the sella, and the structure in association with this part of sella is the inferior intercavernous sinus. Measurements of the sella turcica bridge (STB), carotico-clinoid foramen (CCF), interclinoid foramen (ICF) on both sides and that of the ossified bar and foramen formed by itself were taken with the help of ImageJ software. The values observed for the measurements of different parameters of STB and its components, for CCF and ICF were bilaterally different. While the values for the osseous bar and foramen formed by it cannot be compared because of its unilateral occurrence. The presence of foramen around the inferior intercavernous sinus may lead to difficulty in performing procedures like transsphenoidal surgery (TSS) or extended TSS (eTSS) while extracting intradural lesions, thus increasing the chances of haemorrhage.

Probing the effect of a room temperature ionic liquid on phospholipid membranes in multilamellar vesicles.

The large number of potential applications of ionic liquids (ILs) requires an understanding of their environmental impacts including their adverse effects on microorganisms living in soil and water. The molecular mechanism of toxic activities of these liquids is yet to be understood in detail. Any foreign molecules, interacting with an organism, have to encounter first the cellular membrane, which is predominantly composed of the lipid bilayer. In this work, multilamellar vesicles (MLV) of phospholipids have been used to shed light on the effect of an IL on the structure of a cellular membrane. The MLVs formed by the zwitterionic lipid, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) are found to shrink as a consequence of interaction with an imidazolium-based IL, 1-decyl-3-methylimidazolium tetrafluoroborate ([DMIM] [BF4]). The absorbed ILs significantly modify the surface charge of the MLVs. While these observations indicate a strong membrane-IL interaction, synchrotron-based small angle X-ray diffraction (SAXD) measurements provide a structural description of the interaction. SAXD and Fourier transform infrared spectroscopy studies clearly reveal a disordering effect of the IL on the conformational organization of the lipid chains. The presence of the negatively charged lipid 1,2-dipalmitoyl-sn-glycero-3-phospho-L-serine sodium salt (DPPS) in MLVs plays an important role in disordering the chains in the membrane and inter-bilayer interactions.

Time-Reversal Symmetry Breaking in Re-Based Superconductors.

To trace the origin of time-reversal symmetry breaking (TRSB) in Re-based superconductors, we performed comparative muon-spin rotation and relaxation (µSR) studies of superconducting noncentrosymmetric Re_{0.82}Nb_{0.18} (T_{c}=8.8 K) and centrosymmetric Re (T_{c}=2.7 K). In Re_{0.82}Nb_{0.18}, the low-temperature superfluid density and the electronic specific heat evidence a fully gapped superconducting state, whose enhanced gap magnitude and specific-heat discontinuity suggest a moderately strong electron-phonon coupling. In both Re_{0.82}Nb_{0.18} and pure Re, the spontaneous magnetic fields revealed by zero-field µSR below T_{c} indicate time-reversal symmetry breaking and thus unconventional superconductivity. The concomitant occurrence of TRSB in centrosymmetric Re and noncentrosymmetric ReT (T=transition metal), yet its preservation in the isostructural noncentrosymmetric superconductors Mg_{10}Ir_{19}B_{16} and Nb_{0.5}Os_{0.5}, strongly suggests that the local electronic structure of Re is crucial for understanding the TRSB superconducting state in Re and ReT. We discuss the superconducting order parameter symmetries that are compatible with the experimental observations.

Village-scale (Phase III) evaluation of the efficacy and residual activity of SumiShield® 50 WG (Clothianidin 50%, w/w) for indoor spraying for the control of pyrethroid-resistant Anopheles culicifacies Giles in Karnataka state, India.

OBJECTIVE: There is an urgent need to test and incorporate new molecules with promising efficacy and novel mode of action to control insecticide-resistant mosquito vectors for disease control. We tested a new compound, clothianidin (SumiShield 50 WG), for its efficacy as an indoor residual spray (IRS) for the control of pyrethroid-resistant Anopheles culicifacies (Diptera: Culicidae) in comparison with pirimiphos methyl (Actellic CS) as a positive control. METHODS: Ten villages were selected, five each for IRS with clothianidin (300 mg AI/m2 ) and pirimiphos methyl (1000 mg AI/m2 ) in Almatti Dam catchment area in Karnataka state, India. Entomological parameters were monitored in these sprayed villages using standard methods. Assessment of quality of spray was performed by analysing the insecticide content in the filter paper samples collected from sprayed houses. Perceptions of spray men and inhabitants were recorded post-spray on safety of these molecules. RESULTS: The mean applied to target ratio of content was 1.7 (n = 29) for clothianidin and 1.8 (n = 50) for pirimiphos methyl on filter paper samples analysed. Residual activity (≥80% mortality in exposed mosquitoes) after 24 h post-exposure of SumiShield WG was 5 months and increased to 6 months when the holding period was extended to 120 h and that of Actellic CS was 3 months at 24-h holding period and extended to 4 months at 120-h extended holding period. The mean densities of An. culicifacies in both arms fell drastically post-spray. In light trap collections, density of mosquitoes collected indoors was lower than outdoors in both arms indicating effectiveness of IRS. SumiShield WG was more efficacious in reducing the per-structure density than Actellic CS. The proportion of nulliparous mosquitoes was higher than that of parous mosquitoes during post-spray collections in both arms. The majority of adverse events reported were transitory and subsided without medication. CONCLUSION: Indoor residual spraying with SumiShield WG was found effective, operationally feasible and safe, and it is effective for up to 6 months.

Interface induced magnetic properties of Gd/Co heterostructures.

Antiferromagnetic coupling between rare-earth and transition metal ferromagnetic layers gives rise to various magnetic ground states in heterostructures of these materials. Interface structure and morphology tend to play important roles in magnetic properties of such systems. Interface induced magnetization in Gd/Co heterostructures has been studied using a combination of structural and magnetic characterization techniques. The interface morphology of the Gd/Co system was varied by growing Gd/Co multilayers using magnetron sputtering under different argon partial pressures. Interfacial properties were further modified by annealing the multilayers under high vacuum. The macroscopic magnetization measurements have been correlated with depth dependent structure and magnetic properties of multilayers studied using X-ray and polarized neutron reflectometry techniques. Secondary ion mass spectrometry measurements from both as-deposited and annealed samples also confirmed modification at the interfaces. It has been shown that the interface structure, together with roughness, leads to a unique low-temperature magnetic phase characterized by twisting of Gd and Co moments.